JP2002120973A - Elevator control device - Google Patents

Abstract

(57) [Problem] To provide an inexpensive elevator control device that can safely rescue a passenger trapped between floors even if a failure occurs in an electric motor control system of the elevator. SOLUTION: A hoisting machine driven by an electric motor 1 in which at least a part of a field is constituted by a permanent magnet to elevate an elevator, and an inverter 11 for mutually converting direct current into variable frequency alternating current and alternating current into direct current. , A capacitor 10, which is a storage device provided on the DC side of the inverter 11, and a resistor 14 and an energizing element 15 provided in parallel with the capacitor 10.
, A DC voltage detecting means 20 for detecting a voltage on the DC side of the inverter 11, and a DC voltage commanding means 23 for determining a voltage command value of the DC power supply. The conduction control of the current-carrying element 15 of the power consuming circuit is performed based on the deviation between the DC voltage and the voltage command value output by the DC voltage command means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elevator control apparatus for controlling a permanent magnet type synchronous motor by supplying AC power of a variable voltage and variable frequency converted by an inverter, and more particularly to control of an electric braking force of the motor. It concerns the device.

[0002]

2. Description of the Related Art FIG. 7 shows an elevator control device for controlling an electric motor by supplying AC power of a variable voltage and variable frequency converted by a conventional inverter device described in, for example, JP-A-6-9164. FIG. 2 is an overall configuration diagram. 7, reference numeral 1 denotes an electric motor, 2 denotes a hoisting machine driven by the electric motor 1, 3 denotes a main rope wound around the hoisting machine 2, 4 denotes an elevator car attached to one end of the main rope 3, 5 Is a counterweight attached to the other end of the main rope 3, and 6 is a brake for generating a mechanical braking force. The brake 6 is released and the electric motor 1 is driven to move the elevator car 4 up and down.

Further, 7 is a three-phase AC power supply, 8 is a contact of an electromagnetic contactor which is closed when the elevator is started, 9 is a converter for converting AC to DC, and 10 is installed between DC buses to smooth DC. A smoothing capacitor 11 is a voltage-type inverter device in which a switching element 11a and a diode 11b are connected in anti-parallel for each phase, and converts a DC bus voltage into an AC voltage having a variable voltage and a variable frequency. First current detector for detecting for feedback, 1
An inverter control circuit 3 controls a switching element of the inverter.

Further, 14 is a resistor for consuming regenerative power, 15 is a current-carrying element for flowing a current through the resistor 14, 1
6 is when the voltage of the smoothing capacitor 10 is equal to or higher than a predetermined value.
This is a bus voltage control circuit that issues a conduction command to the energizing element 15.

Reference numeral 17 denotes a speed detector provided on the rotating shaft of the motor 1 for detecting a return speed of the motor 1;
Is a speed command generation circuit that generates an elevator speed command,
19 is a speed control circuit for generating a current command based on the feedback speed and the speed command, 20 is a DC voltage detector for detecting the voltage of the DC bus, 21 is a second current detector for detecting the current of the DC bus, 22 Is an overcurrent detection circuit for monitoring the signal of the current detector 21.

Next, the operation according to the above configuration will be described. When a start command is input to the elevator, the contact 8 of the electromagnetic contactor is closed, and AC power is supplied from the three-phase AC power supply 7 to the converter 9. Converter 9 converts AC power into DC power and supplies the power to inverter device 11. Then, when the brake 6 is released, a speed command is generated from the speed command generation circuit 18, and the feedback speed of the electric motor 1 is detected from the speed detector 17. The speed control circuit 19 sends a current command to the inverter control circuit 13 based on the speed command and the feedback speed. The inverter control circuit 13 has a speed control circuit 19
The inverter device 11 is controlled based on the current command from the first current detector 12 and the feedback current from the first current detector 12 to generate an AC voltage having a variable voltage and a variable frequency to rotate the electric motor 1, and The elevator car 4 is moved up and down through the machine 2 and the main cable 3.

Further, when the electric motor 1 enters a regenerative operation, for example, when the inside of the car performs an ascending operation with no load, the regenerative electric power is charged to the smoothing capacitor 10 through the inverter device 11 to increase the voltage. The bus voltage control circuit 16 detects that this voltage has become equal to or higher than a predetermined value.
, The power of the DC bus is consumed by the resistor 14, the smoothing capacitor 10 is discharged, and the voltage decreases. By repeating this, regenerative electric power from the electric motor is consumed, and the voltage between the DC buses is maintained at a predetermined value or less.

The overcurrent detection circuit 22 constantly monitors the DC current flowing into and out of the inverter 11 by the DC bus current detector 21. If the current value exceeds a predetermined value due to a fault such as a load short circuit, the overcurrent detection circuit 22 will be described. The overcurrent detection circuit 22 recognizes the abnormality, stops the operation of the inverter, activates the brake 6, and immediately stops the elevator immediately.

The AC power supplied to the motor cannot be controlled due to a failure of the motor control system, for example, a failure of the feedback current detector 12, the speed detector 17, the switching element 11a of the inverter, or the contact 8 of the electromagnetic contactor to be OFF. In such a case, the startup of the elevator is prevented due to a serious failure.

[0010]

Since the conventional elevator control apparatus is configured as described above, when the elevator car stops between floors due to a failure of the motor control system,
There was a problem that the elevator could not be restarted and passengers were trapped in the car. Further, in order to prevent confinement, it is conceivable to prepare two systems of detectors and drive circuits as a double system and use them by switching, but there is a problem that the control device becomes expensive.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and even if a failure occurs in an electric motor system of an elevator, a passenger trapped between floors can be safely guided to the nearest floor. It is an object of the present invention to provide an elevator control device that can be rescued.

Still another object of the present invention is to provide an inexpensive elevator control device without providing a dedicated detector or drive device.

[0013]

SUMMARY OF THE INVENTION An elevator control apparatus according to the present invention comprises: a hoist that is driven by an electric motor having at least a part of a field formed by permanent magnets to raise and lower an elevator; and drives the hoist. Device having a switching element and a diode connected in anti-parallel, a smoothing capacitor connected to the DC bus voltage side of the inverter device, and an electromagnetic contactor for electrically separating the inverter device from the three-phase AC power supply A power consumption circuit comprising a resistor and a current-carrying element, provided in parallel with the smoothing capacitor, a DC voltage detecting means for detecting a bus voltage on the DC side of the inverter, and a DC for outputting a voltage command value of the DC power supply. Voltage command means, and a deviation between the DC voltage detected by the DC voltage detection means and the voltage command value output by the DC voltage command means. It is characterized in that a bus voltage control means for conducting control energization elements of the power circuit to the original.

The bus voltage control means may release the brake of the hoist while keeping the electromagnetic contactor and the switching element of the inverter device in a cut-off state.
The bus voltage is controlled to be equal to or less than the voltage command value.

Further, the DC voltage command means is required when the elevator is driven up and down by a DC power supply, and the DC voltage value which is a limit value mainly for the purpose of equipment protection and the power supply is cut off. Sometimes, a motor provided in a hoisting machine driven by an elevator that moves up and down by releasing the brake generates power and selects from at least two DC voltage values that are limiting values of a braking voltage that is regenerated to a DC power supply via an inverter. A voltage command is given to the set value.

The voltage command value of the DC voltage command means corresponds to the unbalanced load of the elevator car and the counterweight in order to suppress the elevating speed when the brake of the elevator is released to an allowable speed, and is provided on the hoist. The motor generates power at the allowable speed, and has a value not exceeding a voltage regenerated by a DC power supply via an inverter device.

Further, the apparatus further comprises a speed detector for detecting a return speed of the motor, and speed command generating means for outputting an elevator speed command, wherein the DC voltage command means is detected by the speed detector. The voltage command value is corrected in accordance with a deviation between the feedback speed and the rescue operation speed output by the speed command generating means.

A current detector for detecting a pulsation of a DC current flowing through the DC bus, and a rotation speed detecting means for detecting a rotation speed of the motor based on the pulsation of the DC current detected by the current detector And a speed command generation means for outputting an elevator speed command, wherein the DC voltage command means includes a rotation speed detected by the rotation speed detection means, and a rescue operation output by the speed command generation means. The voltage command value is corrected according to a deviation from the speed.

Further, the voltage detecting means detects a pulsation of the DC voltage between the DC buses, and a rotation speed detecting means for detecting a rotation speed of the electric motor based on the detected pulsation of the DC voltage; Speed command generating means for outputting the rotation speed detected by the rotation speed detecting means and the rescue operation speed output by the speed command generating means. The voltage command value is modified accordingly.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a configuration diagram of an elevator control device according to Embodiment 1 of the present invention, and particularly shows a configuration during a rescue operation. The same parts as those of the conventional example shown in FIG. However, in the first embodiment, the electric motor 1 is a permanent magnet synchronous motor. Further, as a new code, 23 is a DC voltage command circuit for determining the voltage of the DC bus, 24 is an auxiliary power supply for the DC voltage command circuit 23 and the bus voltage control circuit 16, and the three-phase AC power supply 7 is cut off, This is a backup power supply that operates when the control power supply stops. The elevator control device according to the first embodiment has the same configuration as the above-described conventional example during normal operation, and operates in the same manner.

Next, the operation of the elevator control apparatus according to the first embodiment during the rescue operation will be described.
When the elevator is stopped between floors and cannot be restarted due to a failure in the motor control system, the present control device operates as follows. First, with the contact 8 of the electromagnetic contactor open,
Release the brake 6. In addition, the inverter control circuit 13
, The switching element 11a of the inverter device is kept electrically disconnected.

Normally, there is some unbalanced load between the car 4 and the counterweight 5, and when the brake is released, the hoist 2 rotates so as to be pulled to the heavier one, and the hoist 2 is connected. The electric motor 1 rotates. When the motor 1 is a permanent magnet synchronous motor, the motor 1 acts as a generator due to rotation by external force, and the generated output is supplied to the inverter 11. Since the switching element 11a of the inverter is electrically disconnected, the power generated from the motor 1 is supplied to the DC bus via the diode 11b of the inverter. The electric motor generates a braking force by the current generated here.

However, since converter 9 does not regenerate power to the power supply side, the bus voltage gradually rises, and when the induced voltage of the motor and the bus voltage are balanced, power does not flow from the motor to the DC bus, and Becomes zero. Therefore, in the control device according to the first embodiment, in order to suppress the speed of the electric motor to be equal to or less than the rescue operation speed commanded from the speed command generation circuit 18, based on the unbalanced load set in advance according to the load in the car, DC voltage command circuit 23 outputs a voltage command value. When the bus voltage exceeds the voltage command value, the bus voltage control circuit 16 turns on the energizing element 15 so that the power stored in the DC bus is
4 and the voltage of the capacitor 10 is reduced. By repeating this, the bus voltage is kept below the voltage command value, and the braking force of the electric motor is continuously ensured.

The resistor 14 functions equivalently as a braking resistor of the motor 1. By setting the bus voltage to be equal to or less than the voltage command value, the car can be driven to the nearest floor while keeping the speed of the elevator car at a safe speed.

The reason why the elevator car can be controlled by controlling the bus voltage is as follows.
Considering that the induced voltage is proportional to the speed, the current is proportional to the voltage difference between the induced voltage and the bus voltage, and the braking torque is proportional to the current in the permanent magnet type synchronous motor, the bus voltage and the motor speed, the braking torque Has the relationship shown in FIG. Also, considering the steady speed, the braking torque can be regarded as an unbalanced load, so if the bus voltage is controlled according to the unbalanced load, the motor speed can be suppressed to a predetermined value or less, and the elevator car Speed can be controlled.

As described above, the elevator control apparatus according to the first embodiment of the present invention provides a speed detector, a feedback current detector, a switching element of an inverter, and a magnetic contactor which are considered to be faulty during rescue operation. It is possible to safely drive the elevator car to the nearest floor and rescue the passengers without using the vehicle. In the above method, it is necessary to grasp the relationship between the bus voltage, the motor speed, and the braking torque shown in FIG. 2 for each motor, and to accurately detect the unbalanced load during the rescue operation.

On the other hand, as a configuration not using the relational data of the bus voltage, the motor speed, and the braking torque shown in FIG.
Embodiment 2 of the present invention shown in FIG. 3 is conceivable.

Embodiment 2 FIG. 3 is a configuration diagram of an elevator control apparatus according to Embodiment 2 of the present invention, and the same parts as those of Embodiment 1 of the present invention shown in FIG. The DC voltage command circuit 23 is a circuit that creates a voltage command value based on a difference between the speed command from the speed command generation circuit 18 and the feedback speed from the speed detector 17. The description is omitted because it is the same as FIG.

By providing the DC voltage command circuit 23, the elevator car can be reliably operated at the command speed based on the detected value of the motor speed, so that passengers can be rescued more safely.

However, in the second embodiment of the present invention, since the speed detector 17 is used to obtain the feedback speed, a structure that does not depend on the speed detector is necessary in consideration of the failure of the speed detector. . Therefore, a third embodiment of the present invention shown in FIG. 4 can be considered.

Embodiment 3 FIG. 4 is a configuration diagram of an elevator control apparatus according to Embodiment 3 of the present invention. The same parts as those of Embodiment 2 of the present invention shown in FIG. Also, as a new code, 25
Reference numeral denotes a rotation speed detection circuit for obtaining a rotation speed from the DC bus current detected by the current detector 21.

Next, the operation according to the above configuration will be described. As described above, the switching element 11 of the inverter
Since a is electrically cut off, the electric power generated from the electric motor 1 is supplied to the DC bus via the diode 11b of the inverter. At this time, since the diode 11b operates in the same manner as a diode converter for a three-phase power supply, the voltage and current of the DC bus change as shown in FIG. FIG.
As shown in (1), the current in the DC bus generated by the electric power generated from the motor 1 corresponds to the ripple of the induced voltage of the motor, and exhibits six pulsation waveforms per one electrical angle cycle. By monitoring the pulsation of the current of the DC bus with the current detector 21, the electric angular velocity of the electric motor can be detected. Further, the rotational speed of the electric motor is detected by dividing the electric angular velocity by the number of pole pairs of the motor. be able to.

Embodiment 4 Also, by monitoring the pulsation of the DC bus voltage by the configuration shown in FIG.
It is possible to detect the rotation speed of the electric motor as in the third embodiment of the present invention.

Next, the operation according to the above configuration will be described. As described above, the voltage and current of the DC bus change as shown in FIG. As shown in FIG. 6, the voltage of the DC bus generated by the electric power generated from the electric motor 1 corresponds to the ripple of the induced voltage of the electric motor, and exhibits six pulsation waveforms for one electric angle cycle. By monitoring the pulsation of the voltage of the DC bus with the voltage detector 21, the electric angular velocity of the electric motor can be detected. Further, the rotational speed of the electric motor is detected by dividing the electric angular velocity by the number of pole pairs of the motor. be able to.

[0035]

As described above, according to the present invention, the power consumption circuit is controlled based on the difference between the DC voltage detected by the DC voltage detecting means and the voltage command value output by the DC voltage command means. By controlling the conduction of the current-carrying elements, even when a failure occurs in the motor system, the braking of the elevator can be continuously maintained, and the elevator car can be guided to the nearest floor. Further, it is not necessary to separately provide a detector and a drive circuit, so that an inexpensive elevator configuration can be obtained.

Further, the motor can be maintained at a safe speed, and the elevator car engaged with the motor can be guided to the nearest floor while maintaining the safe speed.

Further, by directing the selection of the DC voltage value, the protection of the equipment is ensured, and the elevator can be controlled at a safe speed even in the event of an elevator failure.

In addition, the elevator speed can be controlled, and the bus voltage can always be reduced to a predetermined value or less even in the case of an elevator failure, so that continuous operation is possible.

Further, it is possible to control the elevator at the command speed reliably, and it is possible to maintain the elevator speed more safely.

Further, since the rotation speed of the motor can be monitored without using the speed detector, the elevator can be guided to the nearest floor at a safe speed even when the speed detector fails.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an elevator control device according to Embodiment 1 of the present invention during a rescue operation.

FIG. 2 is a diagram showing control characteristics of a permanent magnet type synchronous motor according to the present invention.

FIG. 3 is a configuration diagram of an elevator control device according to Embodiment 2 of the present invention during a rescue operation.

FIG. 4 is a configuration diagram of an elevator control device according to Embodiment 3 of the present invention at the time of rescue operation.

FIG. 5 is a configuration diagram of an elevator control device according to Embodiment 4 of the present invention during a rescue operation.

FIG. 6 is a diagram showing voltage and current waveforms of the DC bus during a rescue operation according to the present invention.

FIG. 7 is a configuration diagram of a conventional elevator control device.

[Explanation of symbols]

1 electric motor, 2 hoisting machines, 3 main ropes, 4 elevator cars, 5 counterweights, 6 brakes, 7 three-phase AC power supply, 8 contacts of electromagnetic contactor, 9 converter, 10 capacitor, 11 voltage type inverter device, 11a switching element, 11b diode, 12 current detector, 13 inverter control circuit, 14 resistor, 15 conducting element, 16 voltage control circuit, 17 speed detector, 18
Speed command circuit, 19 speed control circuit, 20 DC voltage detector, 21 current detector, 22 overcurrent detection circuit, 23
DC voltage command circuit, 24 backup power supply circuit, 2
5 rotation speed detection circuit.

Claims (7)

[Claims] 1. An hoisting machine driven by an electric motor having at least a part of a field made of a permanent magnet to raise and lower an elevator, and an inverter device having a switching element and a diode connected in antiparallel to drive the hoisting machine. A smoothing capacitor connected to the DC bus voltage side of the inverter device; an electromagnetic contactor for electrically separating the inverter device from the three-phase AC power supply; a resistor provided in parallel with the smoothing capacitor; A power consumption circuit composed of a current-carrying element; a DC voltage detecting means for detecting a bus voltage on the DC side of the inverter; a DC voltage commanding means for outputting a voltage command value of a DC power supply; Based on the deviation between the DC voltage and the voltage command value output by the DC voltage command means, the conduction control of the energizing element of the power consumption circuit is performed. Control device for an elevator, characterized in that a line voltage control means. 2. The elevator control device according to claim 1, wherein the bus voltage control unit releases a brake of the hoist while keeping the electromagnetic contactor and the switching element of the inverter device in a cutoff state. And controlling the bus voltage to be equal to or less than the voltage command value. 3. The elevator control device according to claim 1, wherein the DC voltage command means is required when the elevator is driven up and down by a DC power supply, and is mainly used for equipment protection. The DC voltage value is a value of the braking voltage that is generated by an electric motor provided on a hoisting machine driven by an elevator that moves up and down by releasing the brake when the power supply is cut off, and is regenerated to the DC power supply through an inverter. An elevator control device, wherein a voltage command is given to a value selected from at least two DC voltage values as limit values. 4. The elevator control device according to claim 1, wherein the voltage command value of the DC voltage command means is controlled by an elevator to reduce an elevator speed to an allowable speed when the brake of the elevator is released. An elevator corresponding to the unbalanced load of the counterweight, wherein the motor provided on the hoist generates power at the allowable speed and does not exceed a voltage regenerated to a DC power supply via an inverter device. Control device. 5. The elevator control device according to claim 1, further comprising: a speed detector for detecting a return speed of the electric motor; and speed command generating means for outputting an elevator speed command. The voltage command means is configured to correct the voltage command value according to a deviation between the feedback speed detected by the speed detector and the rescue operation speed output by the speed command generation means. Control device. 6. The elevator control device according to claim 1, wherein a current detector for detecting a pulsation of the DC current flowing through the DC bus, and a pulsation of the DC current detected by the current detector. A rotation speed detection unit that detects a rotation speed of the electric motor, and a speed command generation unit that outputs an elevator speed command.The DC voltage command unit includes a rotation speed detected by the rotation speed detection unit. An elevator control device for correcting the voltage command value in accordance with a deviation from the rescue operation speed output by the speed command generating means. 7. The elevator control device according to claim 1, wherein the DC voltage detecting means detects a pulsation of the DC voltage between the DC buses, and the rotation of the electric motor is performed based on the detected pulsation of the DC voltage. Rotation speed detection means for detecting a speed, and speed command generation means for outputting an elevator speed command, wherein the DC voltage command means includes: a rotation speed detected by the rotation speed detection means; An elevator control device, wherein the voltage command value is corrected according to a deviation from the rescue operation speed output by the generation means.