RU2401504C1 - Electric power converter - Google Patents

Abstract

FIELD: electricity. ^ SUBSTANCE: hereunder is description of specific abnormalities and fault details as well as corrective measures against them which could possibly occur in electric power converters that actuate and control permanent-magnet synchronous motors. Electric power converter capable to work stably has protective function and takes adequate measures against such faults that could possibly occur. ^ EFFECT: reliability improvement. ^ 3 cl, 4 dwg

Description

FIELD OF THE INVENTION

The present invention relates to electric power converters that drive and control permanent magnet synchronous motors.

State of the art

Permanent magnet synchronous motors (hereinafter referred to simply as “electric motors”) are known as highly efficient electric motors compared to the most commonly used conventional asynchronous electric motors, since the magnetic field is set using a permanent magnet, which eliminates the need for an excitation current, and the current is not flows through the rotor, which leads to the absence of secondary losses in copper. While induction motors are commonly used in electric rail cars, the use of permanent magnet synchronous motors in rail cars has been shown to improve their efficiency in recent years.

In electric power converters used in controllers of electromotor railway cars that drive and control permanent magnet synchronous motors, stable operation is required, in which the possibility of suspension of work due to failure or breakdown is reduced to an extremely small degree, to ensure stable operation of electromotor railway wagons. To meet this requirement, how to protect power circuit controllers is the most important issue when using permanent magnet synchronous motors in electric rail cars. In other words, it is necessary to find out anomalous phenomena that could possibly occur in electric power converters, and take appropriate measures against these anomalies in order to eliminate emergency suspensions of power converters and to maintain power converters without breakage.

An electric power converter is made of a large number of electrical / electronic parts, for example electronic parts, such as sensors and a microprocessor, semiconductor parts, such as switching elements, conductive elements such as cables and busbars that connect these parts to each other, and insulating elements. For this reason, failure or malfunctioning can in principle occur in the constituent element, i.e. in each of the parts making up the electric power converter, and, in this case, abnormal phenomena occur in the circuits, such as overcurrent and voltage overload. In addition to this, temporary overcurrent or voltage overload can sometimes occur in circuits due to fluctuations in the supply voltage specific to electric railways, or due to various disturbances associated with vibration of a railway carriage and vibration of rails.

In addition, permanent magnet synchronous motors, other than the most commonly used asynchronous motors, always generate voltage during rotation by interacting with the magnetic field of the built-in permanent electromagnets, even without externally supplied electrical energy.

Typically, electromotor rail cars move together, with a plurality of cars connected in the form of a train, and a plurality of electric power converters and electric motors, each, are distributed on a plurality of cars. Thus, even when, for example, one of the electric power converters, among the plurality of electric power converters on a train, accidentally stops due to a failure, railway cars can continue to move using other normal electric motors. On the other hand, an electric motor connected to a stopped electric power converter is still forced to rotate the wheels continuously, generating a voltage proportional to its rotation speed.

Accordingly, depending on the types of failures occurring in the electric power converter during the movement of railroad cars, current is continuously supplied to the damaged part by means of a voltage generated by the electric motor, so that the damaged part may be further damaged, or this may cause heat accumulation.

For such a case, a protective function is required to prevent breakage of the electric power converter in such a way that the system controller monitors the signals from the voltage sensor, current sensor or the like provided in the electric power converter, and when the monitored value, for example, exceeds a predetermined value or something similar, the system controller determines that an abnormal phenomenon has occurred, and disconnects the internal contactors and switching elements in accordance with previously specified logical rules.

However, it is wrong to disconnect all contactors and switching elements in the electric power converter when an abnormal phenomenon occurs, since time is spent restarting the electric power converter, which temporarily slows down the operation of railway cars, and the number of contactor operations and the like increases unnecessarily, which accelerates the wear of their moving parts. In addition, damage to abnormal areas may increase if improper measures are taken. For this reason, the electric power converter must have a protective function, which makes it possible to take the right measures against various types of abnormal phenomena and failures occurring in the electric power converter, in order to prevent the converter from breaking, while at the same time preventing unnecessary suspension of its operation.

One of the methods is described as known from the literature in Patent Document 1, in which a case is considered where a failure occurs in an inverter that drives and controls a permanent magnet synchronous electric motor while electric rail cars move, contactors are provided for disconnecting the connection between the inverter and the permanent magnet synchronous motor so as not to cause additional damage to the inverter electrically generated by the electric motor energy, while the inverter and the permanent magnet synchronous motor are isolated from each other by contactors when an inverter failure is detected.

Patent Document 1: Japanese Patent Application Laid-Open No. H08-182105.

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

According to the method of Patent Document 1, since the inverter and the permanent magnet synchronous motor can be isolated from each other by contactors when an inverter failure is detected, further damage to the damaged portion, as described above, from electric energy generated by the electric motor during movement can be prevented. Patent Document 1, cited above, describes that contactors located between the inverter and the motor are disconnected when the inverter breaks, but does not describe any specific abnormal phenomena that could possibly occur in every part, including the inverter, the electric power converter, nor how to take action against the details of individual anomalous phenomena.

As described above, for the stable service of electromotor railcars, it is critical to provide in advance the protective function of taking the right measures against specific anomalous phenomena that could possibly occur in electric power converters. However, using the subject matter of Patent Document 1, it is not possible to take measures against specific abnormal phenomena that could possibly occur in electric power converters.

The present invention is intended to solve the problem described above, and the aim of the present invention is to provide an electric power converter having a protective function that makes it possible to take measures against various abnormal phenomena that might possibly occur in an electric power converter that drives and controls a permanent magnet synchronous motor.

Problem Solving Tools

An electric power converter is provided in accordance with the present invention with a converter having switching elements for converting AC energy from an AC power source to DC energy; with a capacitor connected in parallel on the DC side of the converter; with an inverter having switching elements connected in parallel with a capacitor for driving and controlling a permanent magnet synchronous motor; with a discharge circuit connected in parallel with said capacitor; with a switch on the side of the power source located between the AC power source and the AC side of the converter; with a switch on the motor side located between the inverter and the permanent magnet synchronous motor; with a voltage sensor of the power source for measuring the voltage of the AC power source; with capacitor voltage sensor for measuring capacitor voltage; with an input current sensor for measuring alternating current on the converter; with an output current sensor for measuring alternating current from the inverter; and with a system controller for controlling the switch on the power supply side, the converter, the discharge circuit, the inverter and the switch on the motor side by receiving input signals from the voltage sensor of the power source, the voltage sensor on the capacitor, the input current sensor and the output current sensor, wherein the system controller when the voltage measured by the voltage sensor on the capacitor becomes equal to or less than the first predetermined value, it turns off all switching elements eobrazovatelya and all the switching elements of the inverter; and when the voltage measured by the capacitor voltage sensor becomes equal to or less than the second predetermined value, which is less than the first predetermined value, turns off the switch on the power supply side; wherein the second predetermined value is set smaller than the first predetermined converter having switching elements for converting alternating current energy from an alternating current power source to direct current energy; with a capacitor connected in parallel with the DC side of the converter; with an inverter having switching elements and connected in parallel with a capacitor for actuating and controlling a permanent magnet synchronous motor; with a discharge circuit connected in parallel with a capacitor; with a switch on the side of the power source located between the AC power source and the AC side of the converter; with a switch on the motor side located between the inverter and the permanent magnet synchronous motor; with a voltage sensor for measuring the voltage of the AC power source; with capacitor voltage sensor for measuring capacitor voltage; with an input current sensor for measuring alternating current in the converter; with an output current sensor for measuring alternating current from the inverter; and with a system controller for controlling a switch on the power supply side, a converter, a discharge circuit, and a switch on the motor side by receiving input signals from a supply voltage sensor, a capacitor voltage sensor, an input current sensor and an output current sensor, where the system controller when the voltage measured by the voltage sensor across the capacitor becomes equal to or less than the first predetermined value, turns off all switching elements of the converter and all switching elements of the inverter; and when the voltage measured by the voltage sensor on the capacitor becomes equal to or greater than the second predetermined value, which is less than the first predetermined value, turns off the switch on the motor side; and wherein the second predetermined value is set smaller than the first predetermined value to reduce the number of switching operations of the contactor on the motor side.

The effect of the present invention

An electric power converter is provided in accordance with the present invention with a converter having switching elements for converting AC energy from an AC power source to DC energy; with a capacitor connected in parallel on the DC side of the converter; with an inverter having switching elements and connected in parallel with a capacitor for actuating and controlling a permanent magnet synchronous motor; with a discharge circuit connected in parallel with a capacitor; with a switch on the side of the power source located between the AC power source and the AC side of the converter; with a switch on the motor side located between the inverter and the permanent magnet synchronous motor; with a voltage sensor of the power source for measuring the voltage of the AC power source; with capacitor voltage sensor for measuring capacitor voltage; with an input current sensor for measuring alternating current for the converter; with an output current sensor for measuring alternating current from the inverter; and with a system controller for controlling a switch on the power supply side, a converter, a discharge circuit, an inverter and a switch on the electric motor side by receiving input signals from a voltage source voltage sensor, a capacitor voltage sensor, an input current sensor and an output current sensor, where the system controller, when the voltage measured by the voltage sensor on the capacitor becomes equal to or less than the first predetermined value, it turns off all switching elements of the converter the selector and all switching elements of the specified inverter; when the voltage measured by the voltage sensor on the capacitor becomes equal to or less than the second predetermined value, which is less than the first predetermined value, turns off the switch on the side of the power source; and the second predetermined value is smaller than the first predetermined value due to the reduction in the number of switching operations of the contactor on the side of the power source. For this reason, reliable protection work in the event of a short circuit can be achieved and at the same time unnecessary switching of the switch on the power supply side is prevented.

An electric power converter in accordance with another aspect of the present invention is provided with a converter having switching elements for converting AC energy from an AC power source to DC energy; with a capacitor connected in parallel with the DC side of the converter; with an inverter having switching elements and connected in parallel with a capacitor for actuating and controlling a permanent magnet synchronous motor; with a discharge circuit connected in parallel with a capacitor; with a switch on the side of the power source located between the AC power source and the AC side of the converter; with a switch on the motor side located between the inverter and the permanent magnet synchronous motor; with a voltage sensor for measuring the voltage of the AC power source; with capacitor voltage sensor for measuring capacitor voltage; with an input current sensor for measuring alternating current in the converter; with an output current sensor for measuring alternating current from the inverter; and with a system controller for controlling a switch on a power supply side, a converter, a discharge circuit, an inverter and a switch on a motor side by receiving input signals from a supply voltage sensor, a capacitor voltage sensor, an input current sensor and an output current sensor, where the system controller when the voltage measured by the voltage sensor on the capacitor becomes equal to or less than the first predetermined value, disconnects all switching elements of the converter and all switching elements of the inverter; and when the voltage measured by the capacitor voltage sensor becomes equal to or less than the second predetermined value, which is less than the first predetermined value, turns off the switch on the motor side; and wherein the second predetermined value is smaller than the first predetermined value due to the reduction in the number of switching operations of the contactor on the motor side. For this reason, reliable protection work in the event of a short circuit can be achieved and at the same time unnecessary switching of the switch on the motor side is prevented.

Brief Description of the Drawings

Figure 1 is a diagram illustrating an example configuration of an electric power converter applicable to an electric motor rail car controller in accordance with one embodiment 1 of the present invention;

2 is a diagram illustrating an example configuration of a contactor on a power supply side and a contactor on a motor side in accordance with one embodiment 1;

3 is a diagram illustrating an earthing system of an electric power converter in accordance with one embodiment 1 under normal conditions; and

4 is a diagram illustrating the grounding system of an electric power converter in accordance with Embodiment 1 under conditions of an earth fault of its main circuit.

Reference Numbers

1: air wire

2: current collector

3: wheels

4: rails

5: breaker

6: transformer

10, 10u, 10v: contactor on the side of the power supply

11: main contact

12: electromagnetic coil

13: auxiliary contact

20: converter

21-24: switching elements

30: capacitor

40: ground circuit

41, 42, 43: impedance element

44: ground fault detector

50: discharge circuit

51: resistor

52: switching device

60: inverter

61-66: switching elements

70, 70u, 70v, 70w: motor-side contactor

80: permanent magnet synchronous motor (electric motor)

90: voltage sensor

91: current sensor

92: voltage sensor

93-95: current sensors

96: rotation sensor

100: system controller and

200: electric power converter housing / railway carriage housing.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1

1 is a diagram illustrating an example configuration of an electric power converter applicable to an electric motor railcar controller in accordance with Embodiment 1 of the present invention. As shown in figure 1, electric energy is supplied to the main circuit of the power converter from the air wire 1 (its AC voltage, as a rule, is equal to 20-25 kV) through the current collector 2 and is supplied to the primary side of the transformer 6 through the chopper 5. The other end the transformer 6 is connected to the rails 4 with the ground potential through the wheels 3. Note that the chopper 5 has the ability to interrupt the fault current generated when a short circuit occurs; on the other hand, the contactor 10 on the side of the power source and the contactor 70 on the side of the motor, which will be described later, do not have the ability to interrupt such a fault current.

The transformer 6 stepwise reduces the voltage supplied to its primary winding to output corresponding stepwise reduced voltages to its secondary and tertiary windings. The voltage from the secondary winding is supplied to the input of the converter 20 through the contactor 10 on the side of the power source, which is a switch on the side of the power source, and through a current sensor 91, which measures the current supplied to the input of the converter. On the other hand, the voltage of the tertiary winding is measured as the voltage of the AC power source VS using the voltage sensor 90 and is supplied to the input of the system controller 100.

It is noted here that the voltage sensor 90 is provided for measuring the voltage of the air wire 1. The voltage sensor 90, although it is preferably located on the tertiary side of the transformer 6, as shown in figure 1, due to the weakening of the influence of higher harmonics from the Converter 20, and also, for ease of isolation, it can be located not only on the side of the AC power source, that is, on the secondary side of the contactor 10 on the side of the power source, but also on the side of the primary winding a 6.

The contactor 10 on the side of the power source is located between the secondary winding of the transformer 6 and the converter 20. The switching operation of the contactor can be controlled by the system controller 100 by the signal K output from it, and its operating state is supplied to the system controller 100 by the signal FK. Although FIG. 1 illustrates such a configuration that two input AC lines, both are switched by contactors 10u and 10v on the power supply side, a contactor may be provided on any one of the input AC lines. The configuration of these contactors will be described in detail later.

A current sensor 91 measures the input current IS of the converter 20 to output the measured value to the input of the system controller 100. Converter 20 consists of a bridge circuit formed by switching elements 21, 22, 23 and 24, and converts the input AC voltage to DC voltage by means of pulse-width-modulation (PWM) control of each switching element in response to a CG signal from a system controller 100 for receiving converted voltage at the output. The state of each switching element is input back to the system controller 100 by a CGF signal. When current overload occurs in one of the switching elements, when the control voltage for the switching elements decreases, when an excessive temperature is detected in one of the switching elements, and when the operation of the switching elements does not correspond to the CG signal, this information is input to the system controller 100 by the CGF signal.

The switching elements 21-24 are preferably made from elements of insulated gate bipolar transistors (IGBTs) or elements of an intelligent power management module (IPM), in each of which an antiparallel diode is embedded. Since the control methods of the converter 20 and its configuration are described in detail in various sources of the prior art, their detailed descriptions are omitted. The converter 20, although shown in FIG. 1 as a two-level converter circuit, may be a converter circuit with three or more levels.

The output side of the converter 20 is connected in parallel with the capacitor 30 to smooth the DC voltage. The voltage VDC of the capacitor 30 is measured using a voltage sensor 92 for supplying to the system controller 100.

The output side of the converter 20 is additionally connected to the ground circuit 40. The ground circuit 40 separates the DC voltage of the VDC of the converter 20 using the impedance elements 41 and 42, and the connection point of the impedance elements 41 and 42 is grounded to the electric power converter housing 200 / railroad car body through the impedance element 43. The voltage on the impedance element 43 or the current through it is monitored by an earth fault detector 44, and the monitored value is supplied to the input of the system controller 100 by an IGS signal. The impedance elements 41 and 42 each consist of a capacitor and a resistor, or a combination thereof. The impedance element 43 preferably consists of a resistor.

The discharge circuit 50, which is a discharge means consisting of a resistor 51 and a switching device 52, is provided for discharging the capacitor 30. The switching device 52 is turned on and off by the system controller 100 at the OVG signal at its output, and the operating states of the switch are supplied to the controller 100 systems by OVF signal. The switching device 52 preferably consists of a switching element, such as a thyristor, IGBT or IPM.

An inverter 60 is provided for receiving a DC voltage from a capacitor 30 and converting it to a predetermined AC voltage having a predetermined frequency at the output. The inverter 60 consists of a bridge circuit formed by switching elements 61, 62, 63, 64, 65, and 66, for controlling with PWM (pulse-width modulation) each switching element based on an IG signal from the system controller 100. The state of each switching element is input back to the system controller 100 by an IGF signal. When current overload occurs in one of the switching elements, when the control voltage for the switching elements decreases, when an excess temperature is detected in one of the switching elements, or when the operation of the switching elements does not correspond to the IG signal, this information is supplied to the system controller 100 by the IGF signal.

The switching elements 61-66 preferably consist of IGBT elements or IPM elements, in each of which an antiparallel diode is integrated. Since the control methods of the inverter 60 and its configuration are described in detail in various sources of the prior art, their detailed descriptions are omitted. The inverter 60, although shown as a two-level inverter circuit in FIG. 1, may be an inverter circuit with three or more levels.

Current sensors 93, 94 and 95, which measure the output currents from the inverter 60, are provided on its output side. The values measured by each current sensor are supplied to the system controller 100 as U-phase IU current, V-phase IV current and W-phase IW current.

A contactor 70 on the motor side, which is a switch on the motor side, is provided on the output side of the current sensors 93, 94 and 95 for switching the electric motor. The contactor 70 on the motor side consists of a U-phase contactor 70u, a V-phase contactor 70v, and a W-phase contactor 70w, and each of their switching operations is controlled by the system controller 100 by its output signal MMK, and the operational state of each contactor is input to the controller 100 systems by MMKF signal. The configuration of these contactors will be described in detail later.

The output side of the contactor 70 on the motor side is connected to the synchronous electric motor 80 with a permanent magnet (“electric motor”), which drives an electric motor railroad car. The position of the rotor of the electric motor is measured using the sensor 96 of rotation and is input to the controller 100 of the system as a signal of position θ. A sensorless control that calculates the position signal θ from the voltage and current of the motor 80 can be used without the rotation sensor 96 provided.

The power supply side contactors 10u and 10v and the motor side contactors 70u, 70v and 70w are described in detail here. FIG. 2 is a diagram illustrating an example configuration of contactors 10u and 10v on the side of power supplies and contactors 70u, 70v and 70w on the motor side of Embodiment 1. As shown in FIG. 2, each of these contactors consists of a main contact 11, which turns on and off the main circuit, the electromagnetic coil 12, which drives the main contact 11, and the auxiliary contact 13, which mechanically connects the main contact so that it closes synchronously with the closure of the main contact 11 and opens repented simultaneously with his release.

The electromagnetic coil 12 is turned on and off in response to a signal K or a signal MMK supplied from the system controller 100, so that the main contact 11 closes and opens using the driving force of the coil. By providing two different electromagnetic coils, the opening and closing operations of the main contact 11 can be carried out using individual coils, respectively, or by providing a single electromagnetic coil, the main contact 11 can be closed by the force produced by energizing the coil, and opened using a release device a main contact, such as a spring, when there is no force created by powering the coil.

Regarding the motor side contactors 70u, 70v and 70w, they are preferably configured so that the main contact 11 is not opened by the driving force of the electromagnetic coil 12, but by the force of a spring or the like, bearing in mind the situation when the power supply to coil 12 is terminated. This ensures that the motor 80 is isolated from the inverter 60, even when the power source control of the system controller 100 becomes unavailable, as will be described below. The operating state of the main contact 11, detected through the auxiliary contact 13, is input to the system controller 100 by the signal FK or signal MMFK.

While the contactors 10u and 10v on the power supply side and the contactors 70u, 70v and 70w on the motor side are described above as mechanical type contactors, each of the contactors is not limited to them, insofar as it works when the circuit is switched (on and off) and capable of checking operation, and may, for example, be a semiconductor type proximity switch. In addition, although the auxiliary contact 13 is configured to synchronously close with the closure of the main contact 11 and synchronously open with its opening, the auxiliary contact, in contrast, can be configured to synchronously open with the closure of the main contact 11 and synchronously close with its opening. Thus, by summing the status of the auxiliary contact 13 to the input of the system controller 100, the operations of the contactors 10u and 10v on the power supply side and the contactors 70u, 70v and 70w on the motor side can be continuously monitored, as will be described below, by the system controller 100, which makes it possible to detect contactor anomalies.

A system controller 100 is described herein. The controller 100 of the system receives, from outside, for example, from a driver’s cabin (not shown) an electric railcar or the like, signals, including each operation mode command for moving forward, moving backward, moving with energy consumption and regenerative movement, stop motion commands and commands braking force to control each component of the electric power converter described above. The system controller 100 also receives signals from each component indicating their operating states, as described above. By such a configuration of the system controller 100, each component of the electric power converter can be optimally controlled in response to signals from a driver's cab or the like.

Although FIG. 1 shows such a configuration that one circuit of the converter 20 is connected to the second winding of the transformer 6, and another circuit of the inverter 60 is connected to the output side of the converter 20, a plurality of circuits can be configured, each of which has a converter 20 that connects to the secondary winding of the transformer 6, and a plurality of circuits, each of which has an inverter 60, which is connected in parallel on the output side of the converter 20. This configuration can also be applied when the secondary winding tr nsformatora 6 is divided into a plurality of windings to which the converter 20 and inverter 60 are attached individually.

With this configuration of the electric power converter, the details of the anomalous phenomena that are likely to occur, and the corresponding measures that should be taken if anomalous events occur, will be described below.

Here, anomalous phenomena are classified into the following three categories for taking various measures in accordance with the importance of the anomalies and whether the anomalies are short-term or not, after the operation of the power converter is stopped by disconnecting the switching elements, the contactor 10 on the side of the power source, the contactor 70 on side of an electric motor or the like.

Category A: an anomaly that makes it possible to automatically restart the power converter, provided that a predetermined time has passed (about several seconds) after the disappearance of a situation that is defined as an anomaly;

Category B: an anomaly that makes it possible to restart the power converter, provided that the situation that is defined as an anomaly disappears, and manual manipulation is also performed, such as manipulating the reset button; and

Category C: An anomaly that prohibits restarting as such.

The reasons for classifying anomalies by Category A, Category B and Category C are described. Category A means anomalies that are thought to occur temporarily under the influence of disturbances such as voltage fluctuation of the overhead wire 1, the influence or operating conditions of other electromotor rail cars, and slippage wheels. Since such anomalies do not lead to a direct breakdown of the power converter, an automatic restart is allowed, which eliminates the deterioration in the performance of the movement of the electric motor railway car due to the stop of the power converter.

Category B means anomalies that probably do not occur under the influence of the above disturbance, but occur, probably, under the influence of anomalies in the power converter itself and can further increase its damage during automatic restart. For this reason, a restart is allowed through manual manipulation, that is, only when a person explicitly chooses a restart.

Category C means anomalies that obviously increase damage to the power converter during a restart, and therefore prohibits restarting by itself.

Furthermore, if an anomaly classified by Category A occurs a predetermined number of times during a predetermined time interval, this anomaly is preferably considered Category B. For example, if a Category A anomaly occurs twice in a row within three minutes, it is considered that the anomaly probably not due to disturbance, but in the circuit itself. Since repeating an automatic restart can damage the power converter, in this case the anomaly is Category B, that is, the power converter is preferably restarted provided that manual manipulation is performed, such as manipulating the reset button (not shown) provided in the driver's cab, or or the like, after the power converter stops when an anomaly occurs by switching off the switching elements, the contactor 10 on the source side Power, contactor 70 on the side of the electric motor and the like.

The classification of each of the anomalies is listed below.

Category A

(1) Input overload (abbreviation: VSOV)

(2) Input voltage reduction (abbreviation: VSLV)

(3) Current overload at the input of the converter (abbreviation: ISOC)

(4) Capacitor voltage overload (abbreviation: FCOV)

(5) Undervoltage on the capacitor (abbreviation: FCLV)

(6) Motor overcurrent (abbreviation: MMOC)

Category B

(7) Discharge Circuit Anomaly (abbreviation: OVCRFF)

(8) Charging anomaly (abbreviation: CHGF)

(9) Microcomputer Anomaly (abbreviation: WDT)

(10) Controlled Power Supply Anomaly (abbreviation: PSLV)

(11) Motor current imbalance (abbreviation: PUB)

(12) Rotation Sensor Anomaly (abbreviation: RSD)

(13) Ground fault of the main circuit (abbreviation: GD)

(14) Contactor Anomaly (abbreviation: KD)

Category C

(15) Converter Switch Element Anomaly (Short: IPMFDC)

(16) Inverter switching element anomaly (abbreviation: IPMFDI)

Methods for determining each anomaly and taking action against them will be described below.

(1) Input overload (abbreviation: VSOV)

When the voltage value VS measured by the voltage sensor 90 becomes equal to or higher than a predetermined value, the system controller 100 determines the voltage as an overload by the input voltage (hereinafter referred to as "VSOV"). It is believed that this phenomenon occurs due to a temporary increase in voltage due to a disturbance on the side of the power source.

The system controller 100, when it detects a “VSOV,” disables the switching elements 21-24 of the converter 20 by a signal CG to stop their switching operations, to prevent damage to them. At the same time, the system controller also turns off the switching elements 61-66 of the inverter 60 by the IG signal, since turning off the switching elements 21-24 prevents the capacitor 30 from supporting the VDC voltage.

If the converter 20 continues to remain in its stopped state, the voltage VDC of the capacitor 30 may drop below the maximum voltage generated by the electric motor 80. In this case, the capacitor 30 is charged by the voltage generated by the electric motor 80 through the diodes of the switching elements 61-66, so that the voltage VDC becomes equal to the maximum generated voltage. However, since the maximum generated voltage of the electric motor 80 at the maximum speed of the electric motor railway car is usually set to lower than the maximum acceptable voltage VDC, determined by the voltage that the switching elements 21-24 and the switching elements 61-66 can withstand, the converter power does not get damaged. Accordingly, the contactor 70 on the motor side can remain in the on state.

In this case, the contactor 70 on the motor side can, of course, be switched off. However, this is not preferable, since the contactor 70 performs a mechanical action, and therefore, frequent switching of the contactor leads to wear of its contacts and the drive mechanism, shortening its useful life. Disconnecting the contactor 70 is also not preferable, since the steps for turning it on necessary to restart the power converter make the restart time longer.

If the maximum voltage generated by the electric motor 80 at the maximum speed of the electric railcar is higher than the maximum acceptable voltage VDC of the capacitor 30, determined by the voltage that the switching elements 21-24 and the switching elements 61-66 can withstand, the contactor 70 on the motor side is turned off .

(2) Input voltage reduction (abbreviation: VSLV)

When the voltage value VS measured by the voltage sensor 90 becomes equal to or less than a predetermined value, the system controller 100 determines that a power failure occurs in the overhead wire 1, and determines the voltage as an input voltage reduction (hereinafter referred to as "VSLV") . It is believed that this phenomenon occurs due to power failure or an abnormal voltage drop in the overhead wire 1.

The system controller 100, when "VSLV" is detected, takes measures similar to the measures against "VSOV" to prevent the reverse application of the air wire 1 with voltage from the converter 20. The contactor 70 on the motor side can also remain in the on state, similar to the case with "VSOV".

(3) Current overload at the input of the converter (abbreviation: ISOC)

When the current value IS measured by the current sensor 91 becomes equal to or greater than a predetermined value, the system controller 100 determines the input current of the converter 20 as excessively large and determines the current as current overload at the input of the converter (hereinafter referred to as “ISOC”). It is believed that this phenomenon occurs due to a disturbance, such as a sudden change in the voltage of the air wire 1, an anomaly in the control of the converter 20, an anomaly in the switching elements 21-24 and a failure due to a short circuit in the main circuit around the input and output nodes of the converter 20 .

The system controller 100, when "ISOC" is detected, disables the switching elements 21-24 of the converter 20 by the CG signal to stop their switching operations, so that they do not fail due to overcurrent. The system controller also turns off the switching elements 61-66 of the inverter 60 according to the IG signal, since turning off the switching elements 21-24 prevents the capacitor 30 from supporting the VDC voltage. The system controller also disconnects the contactor 10 on the side of the power source by signal K, if overcurrent is caused by the malfunctioning of switching elements 21-24 (in a state that does not allow operation for switching in accordance with the signal CG), due to a short circuit in them or due to damage due to a short circuit in the main circuit around the input and output nodes of the converter 20, since it is difficult to reliably prevent overcurrent only by disconnecting the switching elements ntov 21-24.

It is believed that "ISOC" is caused mainly by such a disturbance as a sudden change in voltage of the air wire 1. Since both ends of the capacitor 30 are not short-circuited, unless a short circuit occurs simultaneously in the switching element in the upper arm and in the switching element in the lower the shoulder of the converter 20, or when a fault due to a short circuit occurs on its output side, no current flows to the converter from the motor 80. For this reason, the contactor 70 on the electric side vigatelya not disabled.

In the event that a short circuit occurs simultaneously in the switching element in the upper arm and in the switching element in the lower arm of the converter 20, or a failure due to a short circuit occurs on its output side, the voltage VDC of the capacitor 30 decreases rapidly, as described below. Since the contactor 70 on the motor side is turned off when such a sharp decrease is detected, the power converter can be protected even in such a situation.

Although the voltage VDC of the capacitor 30 may drop below the maximum voltage generated by the motor 80, if the converter 20 continues to remain in its stopped state, the contactor 70 on the motor side may remain in the on state, as discussed above.

(4) Capacitor voltage overload (abbreviation: FCOV)

When the voltage value VDC measured by the voltage sensor 92 becomes equal to or greater than a predetermined value, the system controller 100 determines the voltage of the capacitor 30 as excessively large and determines the voltage as an overload by the voltage of the capacitor (hereinafter referred to as “FCOV”). It is believed that this phenomenon occurs when the voltage VDC of the capacitor 30 cannot be controlled normally due to the abnormal control of the converter 20, or occurs due to a temporary disturbance on the part of the power source.

The system controller 100, when “FCOV” is detected, disables the switching elements 21-24 of the converter 20 and the switching elements 61-66 of the inverter 60 by the CG signal and the IG signal, respectively, to stop their switching operations, so that they do not fail under the action VDC capacitor voltage, if it exceeds the voltage that these elements can withstand. At the same time, the system controller includes a discharge circuit 50 by an OVG signal to discharge the capacitor 30 through a switching device 52 and a resistor 51.

In this case, when the voltage VDC of the capacitor 30 becomes lower than the voltage on the power supply side of the converter 20, current flows into the capacitor 30 and the connected discharge circuit 50 from the power supply side through antiparallel diodes built into the switching elements 21-24 of the converter 20, at this, the resistor 51 could be damaged due to heat. For this reason, the contactor 10 on the side of the power source is turned off by signal K.

Similarly, when the voltage VDC becomes lower than the maximum voltage generated by the motor 80, current flows into the capacitor 30 and the discharge circuit 50 from the side of the motor 80 through antiparallel diodes built into the switching elements 61-66 of the inverter 60, while the resistor 51 could would be damaged due to heat. For this reason, the contactor 70 on the motor side is switched off by the signal MMK.

(5) Undervoltage of the capacitor (abbreviation: FCLV)

When the value of the VDC voltage measured by the voltage sensor 92 becomes equal to or lower than the first predetermined value, the system controller 100 determines the voltage VDC of the capacitor 30 as excessively low and determines the voltage as a voltage reduction of the capacitor (hereinafter referred to as "FCLV"). It is believed that this phenomenon occurs mainly in situations where the voltage of the overhead wire 1 drops due to the high value of its impedance, for example, when an electromotor railway car moves far from the transformer substation that supplies energy to the overhead wire 1, or when, simultaneously, another electromotor railway carriage, when driving with energy consumption, is located on the same air wire from which the carriage receives electric energy.

The system controller 100, when "FCLV" is detected, disables the switching elements 21-24 and the switching elements 61-66 by the CG signal and the IG signal, respectively, to stop their switching operations, to prevent further voltage drop of the capacitor VDC, and suppresses the voltage drop VDC capacitor 30 by reducing energy consumption of the electric motor 80.

When the voltage drop VDC of the capacitor 30 is caused by a change in the impedance of the air wire 1, as discussed above, the voltage drop of the capacitor VDC can be suppressed using the above operation. However, if a short circuit occurs at or adjacent to both ends of the capacitor 30, and then the voltage VDC of the capacitor 30 decreases due to discharge, even the above operation cannot preclude the voltage drop of the capacitor VDC. In this case, the voltage VDC is further reduced lower than the first predetermined value. When the voltage of the VDC capacitor drops below the voltage from the power supply side of the converter 20, current flows into the capacitor 30 from the power supply side through the internal antiparallel diodes of the switching elements 21-24 of the converter 20, while the current flows to the short-circuited section, so that the power converter could be damaged due to heat. For this reason, when the voltage of the capacitor VDC drops lower than the second predetermined value, which is set lower than the first predetermined value, the contactor 10 on the side of the power supply is also turned off by the signal K.

In addition, if the voltage VDC of the capacitor 30 drops lower than the maximum voltage generated by the electric motor 80, the current flows into the capacitor 30 from the motor 80 through the internal anti-parallel diodes of the switching elements 61-66 of the inverter 60, while the current flows to the short-circuited section, so The power converter may be damaged due to heat. For this reason, when the voltage of the capacitor VDC drops lower than the second predetermined value, the contactor 70 on the motor side is also turned off by the signal MMK.

The second predetermined value for disabling the contactor 10 on the power supply side and the value for disabling the contactor 70 on the motor side can be set as values different from each other. In addition, the conditions necessary to turn off the contactor 10 on the side of the power supply and the contactor 70 on the side of the electric motor can vary based on the voltage from the side of the power supply VS or the rotational speed of the electric motor 80. For example, when the electric motor 80 rotates at low speed, the second the predetermined value is set to a lower value since the low voltage generated by the motor 80 makes it possible to correspondingly low the voltage of the capacitor VDC, pr which contactor 70 on the side of the motor must be switched off. Using this method, the number of switching operations of the contactor 10 on the side of the power supply and the contactor 70 on the side of the motor can be reduced due to the reduction of the cases when they should work, making it possible to suppress the wear of the moving parts of the contactors and, for this reason, extend their service life .

(6) Motor overcurrent (abbreviation: MMOC)

When any value of currents IU, IV, and IW, measured by current sensors 93, ..., 95, becomes a predetermined value or exceeds it, the system controller 100 determines the current of the motor as excessively large and determines the current as current overload of the motor (hereinafter referred to as "MMOC "). It is believed that this phenomenon occurs due to a temporary disturbance, such as a short circuit between the output lines of the inverter 60, a short circuit of the motor windings 80, a malfunction of the control of the inverter 60, and a sudden change in the voltage of the power source.

When the system controller 100 detects an “MMOC”, in particular if this is caused by a short circuit between the output lines of the inverter 60, a current caused by the voltage generated by the electric motor 80 could flow in the short-circuited section and increase its damage. For this reason, the system controller disconnects the switching elements 61-66 of the inverter 60 by the IG signal to stop their switching operations and then disconnects the contactor 70 on the motor side by the MMK signal.

The switching elements 21-24 of the converter 20 and the contactor 10 on the side of the power supply can also be switched off by a signal CG and a signal K, respectively, to stop their switching operations.

(7) Discharge Circuit Anomaly (abbreviation: OVCRFF)

The system controller 100, when the feedback signal OVF is input from the switching device 52 of the discharge circuit 50, shows an anomaly of the switching device 52, defines the anomaly as an anomaly of the discharge circuit (hereinafter referred to as “OVCRFF”). The anomaly of the switching device 52 denotes any situation where current overload occurs in an internal switching element embedded in it (not shown), the control voltage for the switching element is reduced, an excess temperature in the switching element is detected, and a difference between the operation performed by the switching element and is detected the command 'enable' / 'disable'.

When the system controller 100 detects “OVCRFF”, it is believed that the voltage of the VDC capacitor may lose the ability to discharge, or the discharge operation may lose the ability to stop, predicting a situation where the switching device 52 cannot be turned on or cannot be turned off at the same time staying on.

When the voltage of the VDC capacitor cannot be discharged due to the impossibility of turning on the switching device 52, the voltage of the VDC capacitor can exceed the voltages that the switching elements 21-24 of the converter 20 and the switching elements 61-66 of the inverter 60 can withstand and disable these switching elements. Accordingly, the system controller disconnects these switching elements 21-24 and 61-66 to stop their switching operations on the signal CG and signal IG. At the same time, the system controller isolates the power supply side and the motor side from the discharge circuit 50 by disconnecting the contactor 10 on the power supply side and the contactor 70 on the motor side according to the signal K and the signal MMK, respectively, so as to eliminate the possibility of the voltage rise of the capacitor 30 from for flowing current.

When the discharge operation of the switching device 52 loses the ability to stop due to the inability to turn it off while remaining in the on state, the voltage VDC of the capacitor 30 drops to zero. In this case, current flows into the discharge circuit 50 from the power source through the internal antiparallel diodes of the switching elements 21-24 of the converter 20, while the resistor 51 may be damaged due to heating. To prevent this, the contactor 10 on the side of the power supply is turned off.

In addition, current flows into the discharge circuit 50 from the motor 80 through the internal antiparallel diodes of the switching elements 61-66 of the inverter 60, and the resistor 51 may be damaged due to heating. To prevent this, the contactor 70 on the motor side is also turned off.

(8) Charging anomaly (abbreviation: CHGF)

When charging the capacitor 30, when the charging of the capacitor 30 does not complete within a predetermined time interval, the system controller determines this incompleteness as a charging anomaly (hereinafter referred to as "CHGF"). While the capacitor 30 is charged, when starting and restarting the electric power converter, from the tertiary winding of the transformer 6 or from the output of an auxiliary power source (not shown) through a charger (not shown), which consists of a transformer and a rectifier, "CHGF" is detected provided that the voltage value VDC of the capacitor 30 does not reach a predetermined value when passing a predetermined period of time after the start of charging.

When "CHGF" is detected, an earth fault or short circuit is likely to occur in the capacitor 30 or in part of the circuit around it. The system controller 100, for this reason, disables the switching elements 21-24 and the switching elements 61-66 by the signal CG and the signal IG, respectively, to stop their switching operations. At the same time, the system controller disconnects the contactor 10 on the side of the power source and the contactor 70 on the side of the motor according to the signal K and the signal MMK, respectively, to isolate the side of the power source and the side of the motor from the capacitor 30, while preventing the flow of current in the short-circuited section of the circuit with power supply side or motor side 80.

(9) Microcomputer Anomaly (abbreviation: WDT)

When an abnormality of the internal microcomputer (hereinafter referred to as “mikom”) is detected by the mikomu abnormality detector (not shown), the system controller 100 determines the abnormality as a mikomu abnormality (hereinafter referred to as “WDT”).

Since there are various methods for detecting mycoma anomalies in the prior art, their detailed descriptions are omitted. The mikoma anomaly detector consists of hardware components other than the mikoma execution software components and is configured to be able to disable, not through the mikom, the contactor 10 on the side of the power supply, the contactor 70 on the side of the electric motor, converter 20 and inverter 60 and switching on the discharge circuit 50. It is believed that the abnormal phenomenon of the mycoma occurs due to the anomalous result of the operation of the mycoma software under the influence of temporary noise, when the work stops s software by Mick is stopped due to the damage of parts and the like on the circuit board, wherein Mick installed, or a hardware fault and the like in software executed by Mick.

When "WDT" is detected, the software could run abnormally, so that the system controller 100 could give an incorrect output to the converter 20, inverter 60, discharge circuit 50, contactor 10 on the power supply side, or contactor 70 on the motor side, which could cause to the failure of the switching elements 21-24 and the switching elements 61-66. For this reason, the mycoma anomaly detector by the CG signal, the IG signal and the OVG signal, and not through the mikom, turns off the switching elements 21-24 and switching elements 61-66 to stop their switching operations and at the same time turns on the discharge circuit 50 for discharging the capacitor 30, thereby preventing the application of voltage to these switching elements. Since the voltage of the capacitor 30 decreases during discharge, the current flows in the discharge circuit 50 from the power source through the internal antiparallel diodes of the switching elements 21-24 of the converter 20, while the resistor 51 could be damaged due to heating. For this reason, the contactor 10 on the side of the power source is turned off by signal K. Similarly, current can also flow in the discharge circuit 50 from the motor 80 through the internal antiparallel diodes of the switching elements 61-66 of the inverter 60, while the resistor 51 could be damaged due to heating. The contactor 70 on the motor side is therefore switched off by the MMK signal.

(10) Controlled Power Supply Anomaly (abbreviation: PSLV)

When such an anomaly is detected that the voltage of the built-in controlled power supply (not shown) that goes out of a predetermined range, the anomaly detector of the controlled power supply (not shown) is detected - a low-voltage power supply, which, as a rule, produces voltages of 15 V, 5 V and the like for mikoma and electronic circuits, the system controller 100 defines the anomaly as an anomaly of a controlled power supply (hereinafter referred to as "PSLV"). When a situation arises where the voltage of the power source for each electromagnetic coil 12 of the contactor 10 on the side of the power source and the contactor 70 on the motor side and the voltage of the power source for driving the switching elements of the converter 20 and the switching elements of the inverter 60 drops to the corresponding predetermined values or below, the system controller also defines these low voltages as PSLV.

When “PSLV” is detected, the mikom might not work normally, and switching elements 21-24 and switching elements 61-66 could fail due to voltage reduction if the voltage of the power supply to drive the switching elements of the converter 20 and the switching elements of the inverter 60 is reduced. In this case, the system controller 100 directly turns off the switching elements 21-24 and the switching elements 61-66 to stop their switching operations and at the same time turns on the discharge circuit 50 for discharging the capacitor 30, thereby preventing the application of voltage to these switching elements. Since the voltage of the capacitor 30 decreases during discharge, current flows into the discharge circuit 50 from the power source through the internal antiparallel diodes of the switching elements 21-24 of the converter 20, while the resistor 51 could be damaged due to heating. The contactor 10 on the side of the power supply is therefore turned off by signal K. Similarly, current also flows into the discharge circuit 50 from the motor 80 through the internal antiparallel diodes of the switching elements 61-66 of the inverter 60, while the resistor 51 could be damaged from due to heating. The contactor 70 on the motor side is therefore switched off by the MMK signal.

Since the discharge circuit 50 must be reliably turned on even in a situation where the power supply from the controlled power source is completely interrupted, the system controller 100 and the discharge circuit 50 each have a backup power supply circuit (not shown) consisting of an energy storage element such as electrolytic capacitor, to maintain the voltage of the controlled power source after stopping the supply of energy from the controlled power source and to maintain the state of the "on" of the switching device 52 until complete Nia discharge (usually for about three seconds). With the above configuration, even if the power supply from the controlled power source is suddenly cut off during operation, the capacitor 30 can be reliably discharged, and the contactor 10 on the side of the power supply and the contactor 70 on the motor side can be turned off, so that a converter failure can be prevented. electrical power, including switching elements 21-24 and switching elements 61-66.

(11) Motor current imbalance (abbreviation: PUD)

When the imbalance value between the motor currents IU, IV and IW, measured by the current sensors 93-95, becomes larger than the predetermined value, the system controller 100 determines the imbalance as the imbalance of the motor current (hereinafter referred to as "PUD").

When a “PUD” is detected, a winding of the motor 80 or a phase loss by the switching element (failure to turn on) may occur. In this case, the system controller 100 determines that the operation of the power converter is difficult, and turns off the switching elements 21-24 and switching elements 61-66 to stop their switching operations, and turns off the contactor 10 on the side of the power source and the contactor 70 on the side of the electric motor signal K and signal MMK, respectively.

(12) Rotation Sensor Anomaly (abbreviation: RSD)

When the position signal θ measured by the rotation sensor 96 is abnormal, the controller of the system 100 determines the anomaly as an anomaly of the rotation sensor (hereinafter referred to as “RSD”). Since methods for detecting anomalies of the position signal θ are available in the prior art, their description is omitted here.

When "RSD" is detected, the current control of the motor 80 is not carried out normally, and this phenomenon is considered to be an overcurrent of the electric motor due to improper operation of the control and damage to the switching element associated with this, and the voltage overload of the capacitor VDC due to for the electric energy generated by the electric motor 80 flowing in the capacitor 30. For this reason, the system controller determines that the continuation of the power converter is difficult m, and turns off the switching elements 21-24 and switching elements 61-66 to stop their switching operations, and turns off the contactor 10 on the side of the power source and the contactor 70 on the side of the electric motor according to the signal K and the signal MMK, respectively.

(13) Ground fault of the main circuit (abbreviation: GD)

The controller of the system 100, when the IGS signal supplied to its input from the ground fault detector 44 provided in the ground circuit 40, shows a ground fault of the main circuit, defines the indication as a ground fault of the main circuit (hereinafter referred to as "GD").

Here, a description will be made of the grounding system of the electric power converter in accordance with the present invention and the earth fault phenomenon of the main circuit. FIG. 3 is a diagram illustrating a ground system of an electric power converter for Embodiment 1 under normal conditions. As shown in FIG. 3, the grounding system is configured such that the voltage VDC of the capacitor 30 is separated by impedance elements 41 and 42 included in the grounding circuit 40 to ground a potential intermediate with respect to the voltage VDC to the power converter body 200 / housing railway carriage through impedance element 43. In this configuration, since a large current, with the exception of the high frequency current associated with the operations of the switching elements 21-24 and the switching elements 61-66, does not pass through the impedance element 43 under normal conditions, the IGS signal at the input to the system controller 100 from the detector 44 earth fault indicates the absence of a large earth fault in the main circuit.

4 is a diagram illustrating a ground system of an electric power converter for Embodiment 1 in a state of earth fault of a main circuit. Figure 4 shows a case, as an example, in which one of the three phase lines of the motor 80 is grounded to the body 200 of the electric power converter / body of a railway carriage. In this case, the earth fault current flows through the impedance element 43, through the electric power converter housing 200 / railway car body, as shown by the broken line in FIG. 4, and the earth fault detector 44 informs the system controller 100 on this basis of the fault to ground of the main circuit by the IGS signal supplied to the controller input.

When the electric motor railway car moves, in this case, even though the switching elements 61-66 of the inverter 60 are disconnected, the earth fault current continues to flow through the internal diodes of the switching elements 61-66 due to the voltage generated from the rotation of the electric motor 80, damaging power converter. For this reason, the contactor 70 on the motor side must be disconnected.

In the case where the electric motor railway car moves, even though the switching elements 61-66 of the inverter 60 are disconnected, the earth fault current continues to flow through the internal diodes of the switching elements 61-66 due to the voltage generated from the rotation of the electric motor 80, damaging the converter power. For this reason, the contactor 70 on the motor side must be disconnected.

When an earth fault occurs around the input and output nodes of the converter 20, other than the earth fault path shown in FIG. 4, the contactor 10 on the power supply side must also be turned off to interrupt the earth fault current on the power supply side. In addition, the discharge circuit 50 is turned on to discharge the capacitor 30, which otherwise could be a fault current source.

As described above, the system controller 100, when it detects “GD,” turns off the switching elements 21-24 and switching elements 61-66 and turns on the discharge circuit 50 by the OVG signal to discharge the capacitor 30, and also turns off the contactor 10 on the power supply side and the contactor 70 on the motor side by signal K and signal MMK, respectively.

(14) Contactor Anomaly (abbreviation: KD)

When the following situation occurs: although the system controller commands the contactor 10 on the side of the power supply or the contactor 70 on the motor side to turn on by signal K or signal MMK, respectively, the corresponding main contacts 11 and auxiliary contacts 13 synchronized with them are not turned on, and as a result the state continues for a predetermined time interval when the feedback signal KF or the feedback signal MMKF do not show their 'on' status,

or, although the controller instructs any of the contactors to trip on signal K or signal MMK, the corresponding main contacts 11 and auxiliary contacts 13 synchronized with them are not disabled, and as a result, this state continues for a predetermined time interval when the feedback signal KF or MMKF feedback signal does not show their status is 'disabled',

the system controller 100 determines the situation as a malfunctioning of the contactor 10 on the side of the power supply or the contactor 70 on the motor side and defines the situation as an anomaly of the contactor (hereinafter referred to as "KD"). This is due to the fact that the determination of the contactor anomaly is carried out by detecting the occurrence of a specific phenomenon, in which the operating time of the contactors is extended over a predetermined time value. By detecting, therefore, such an anomaly, measures can be taken before the further development of the anomaly in order to achieve a situation where the contactor is not working from a team for him.

In addition, the detection of such an anomaly of contact can be carried out on the basis of the block of the contactor 10 on the side of the power source and the contactor 70 on the side of the electric motor or individually for the contactor 10u and 10v on the side of the power supply and the contactor 70u, 70v and 70w on the side of the electric motor.

When "KD" is detected, not only the main circuit cannot operate normally, but also the motor 80 cannot be isolated from the inverter 60, or the converter 20 cannot be isolated on the side of the power supply, even if such isolation is necessary when each of the anomalies occurs, which are described, which can lead the power converter to a more damaged state.

For this reason, the system controller disconnects the switching elements 21-24 and the switching elements 61-66 according to the signals CG and IG, respectively, to stop their switching operations and turns on the discharge circuit 50 by the OVG signal to discharge the capacitor 30, and disconnects the contactor 10 on the side of the power supply and a contactor 70 on the motor side according to the signals K and MMK, respectively.

In addition to this, with respect to the contactors discussed here, it is believed that they can turn on and off, but their operations take a longer time. Accordingly, with respect to the contactor 10 on the side of the power source and the contactor 70 on the side of the motor, it is believed that they can be disconnected. When an anomaly of the contactor 10 on the power supply side is detected, the chopper 5 may also trip, taking into account the situation where the contactor 10 on the power supply side cannot be turned off.

(15) Converter Switch Element Anomaly (Short: IPMFDC)

The system controller 100 monitors the signal CGF supplied to its input from the converter 20, and when the signal CGF shows any situation where current overload occurs in one of the switching elements, the control voltage for the switching elements is reduced, an excess temperature is detected in one of the switching elements and a mismatch between the on / off state of the switching elements and the on / off switch for them is detected, the controller defines the situation as an anomaly of the switching elec ment converter (hereinafter referred to as "IPMFDC"). Any of these phenomena could lead to the failure of the switching elements.

The system controller 100, when an “IPMFDC” is detected, disables the switching elements 21-24 of the converter 20 by the CG signal to stop their switching operations, so that they do not fail, and at the same time turns on the discharge circuit 50 by the OVG signal to discharge the capacitor 30 through a switching device 52 and a resistor 51. In addition, the controller simultaneously turns off the switching elements 61-66 of the inverter 60 by an IG signal to stop their switching operations.

In this case, when the voltage VDC of the capacitor 30 drops below the voltage on the current source side of the converter 20, current flows in the capacitor 30 and in the discharge circuit 50 from the power source through the internal antiparallel diodes of the switching elements 21-24 of the converter 20, while the resistor 51 can be damaged due to heat. For this reason, the contactor 10 on the power supply side is switched off by signal K. Similarly, when the voltage VDC drops below the maximum voltage generated by the electric motor 80, current flows in the capacitor 30 and in the discharge circuit 50 from the electric motor 80 through the internal antiparallel diodes of the switching elements 61-66 of the inverter 60, while the resistor 51 could be damaged due to heating. The contactor 70 on the motor side is therefore switched off by the MMK signal.

(16) Inverter switching element anomaly (abbreviation: IPMFDI)

The system controller 100 monitors the IGF signal received at its input from the inverter 60, and when the IGF signal shows any situation where current overload occurs in one of the switching elements, the control voltage for the switching elements decreases, an excess temperature is detected in one of the switching elements and a mismatch between the on / off state of the switching elements and the on / off switch for them is detected, the controller defines the situation as an anomaly of the switching element inverter (hereinafter referred to as "IPMFDI"). Any of these phenomena could lead to the failure of the switching elements.

The system controller 100, when detecting "IPMFDI", disables the switching elements 61-66 of the inverter 60 on the IG signal to stop their switching operations, so that they do not fail, and at the same time turns on the discharge circuit 50 according to the OVG signal for discharging the capacitor 30 through a switching device 52 and a resistor 51. In addition, the controller simultaneously turns off the switching elements 21-24 of the converter 20 by the signal CG to stop their switching operations.

In this case, when the voltage VDC of the capacitor 30 drops below the voltage on the power supply side of the converter 20, current flows in the capacitor 30 and in the discharge circuit 50 from the power supply side through the internal antiparallel diodes of the switching elements 21-24 of the converter 20, while the resistor 51 could would be damaged due to heat. For this reason, the contactor 10 on the power supply side is switched off by signal K. Similarly, when the voltage VDC drops below the maximum voltage generated by the electric motor 80, current flows in the capacitor 30 and in the discharge circuit 50 from the electric motor 80 through the internal antiparallel diodes of the switching elements 61-66 of the inverter 60, while the resistor 51 could be damaged due to heating. The contactor 70 on the motor side is therefore switched off by the MMK signal.

At this point, a description of the methods for detecting each anomalous phenomenon and the measures that should be taken against them ends. In addition, the system controller 100 is configured to register in it the details of the above-mentioned anomalous phenomena when any of them occurs, and at the same time informs about the anomaly of an external device provided in the driver's cab, or something similar. This configuration makes it possible to quickly determine the causes of abnormal phenomena.

When one of the anomalies listed below specifically occurs, the main circuit is likely to undergo a short circuit or ground fault, which can lead to a large fault current. For this reason, the chopper 5 is further turned off.

(8) Charging anomaly (abbreviation: CHGF)

(13) Ground fault of the main circuit (abbreviation: GD)

(15) Converter Switch Element Anomaly (Short: IPMFDC)

(16) Inverter switching element anomaly (abbreviation: IPMFDI)

The following anomalies, on the other hand:

(11) Motor current imbalance (abbreviation: PUD)

(12) Rotation Sensor Anomaly (abbreviation: RSD)

would not have occurred, or they have little effect if they occur during the movement of a railway carriage by inertia. Accordingly, the detection processes of both anomalies can be stopped so as not to detect them while driving by the inertia of the railway car (that is, when the converter 20 and the inverter 60 are stopped).

As described above, descriptions are given of specific anomalies and failure details that may possibly occur in an electric power converter that drives and controls a permanent magnet synchronous motor, and measures are taken against specific details. By creating a system controller with a protective function that can take appropriate measures against failures that may possibly occur, it is possible to prevent, for example, shortening the life of contactors due to an increase in the number of switching operations, due to excessive protection operations in the event of anomalies which provide time for restarting the power converter in connection with the time required to reconnect the contactors and charge the capacitor, and disturbing maintenance rail car due to frequent stops the electric power converter. In addition, an increase in damage to the abnormal area due to inappropriate measures can be prevented. For this reason, an electric power converter can be obtained that can operate stably.

Thus, in accordance with the present invention, it is possible to create an electric power converter that can carry out a method of taking measures against specific abnormal phenomena that could possibly occur in electric power converters that drive and control permanent magnet synchronous motors , and also have a protective function, having the ability to take appropriate measures against various abnormal phenomena that could possibly occur it.

The configuration described in the above embodiment is an example of the subject matter of the invention and may be combined with other technology known in the art and may also be modified, for example partially omitted, within the scope of the present invention.

Although the objects of the present invention are described in the description for the case where an electric power converter is used for a controller for an electric motor railway car, the scope is not limited to this. The present invention can also be applied in various related fields, such as electric vehicles and forklifts.

Claims (3)

1. An electric power converter, comprising: a converter having switching elements for converting AC energy from an AC power source to DC energy; a capacitor connected in parallel with the converter on the DC side; an inverter having switching elements and connected in parallel with a capacitor for actuating and controlling a permanent magnet synchronous motor; a discharge circuit connected in parallel with said capacitor; a switch on the side of the power source, located between the AC power source and the AC side of the specified Converter; a switch on the motor side located between said inverter and a permanent magnet synchronous electric motor; a power source voltage sensor for measuring an AC power source voltage;
a capacitor voltage sensor for measuring a voltage on said capacitor; input current sensor for measuring alternating current in the converter; an output current sensor for measuring alternating current from the inverter and a system controller for controlling a switch on the power supply side, a converter, a discharge circuit, an inverter and a switch on the motor side by receiving input signals from a voltage source sensor, a voltage sensor on a capacitor, an input current sensor, and the specified output current sensor, while when the voltage measured by the specified voltage sensor on the capacitor becomes equal to or less than the first previously set value, the system controller turns off all the switching elements of the converter and all switching elements of said inverter; and when the voltage measured by the voltage sensor on the capacitor becomes equal to or less than the second predetermined value, which is less than the first predetermined value, turns off the switch on the side of the power source; and wherein the second predetermined value is set smaller than the first predetermined value to reduce the number of switching operations of the contactor on the power supply side. 2. An electric power converter, comprising: a converter having switching elements for converting AC energy from an AC power source to DC energy; a capacitor connected in parallel on the DC side of the converter; an inverter having switching elements and connected in parallel with a capacitor for actuating and controlling a permanent magnet synchronous motor; a discharge circuit connected in parallel with a capacitor; a switch on the side of the power source located between the AC power source and the AC side of the converter; a switch on the motor side located between the inverter and the permanent magnet synchronous motor; a power source voltage sensor for measuring an AC power source voltage;
a capacitor voltage sensor for measuring a voltage on said capacitor; input current sensor for measuring alternating current from the converter; output current sensor for measuring alternating current from the inverter; and a system controller for controlling a switch on the side of the power source of the converter, a discharge circuit, an inverter and a switch on the side of the electric motor by receiving input signals from a voltage sensor of the power source, a voltage sensor on the capacitor, an input current sensor and an output current sensor, where
the system controller, when the voltage measured by the voltage sensor on the capacitor becomes equal to or less than the first predetermined value, it turns off all switching elements of the converter and all switching elements of the inverter; and when the voltage measured by the capacitor voltage sensor becomes equal to or less than the second predetermined value, which is less than the first predetermined value, turns off the switch on the motor side; and wherein the second predetermined value is set smaller than the first predetermined value to reduce the number of switching operations of the contactor on the motor side. 3. The electric power converter according to claim 1 or 2, in which the system controller sets a second predetermined value based on the voltages measured by the voltage sensor of the power source, or based on the frequency of the output voltage of the inverter.

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