JPH0620321B2 - AC power supply for automobile work - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is used as a power unit for a special vehicle having a working power unit in addition to a traveling power unit for a crane truck, a mixer truck, a power shovel, and other vehicles. To be done.

[Conventional technology]

The rotary power for the work of conventional special vehicles is used by branching the output of the internal combustion engine for vehicle travel by an auxiliary power unit (power take-off, PTO) that extracts the rotational force from the transmission gear to the auxiliary power shaft. It is supposed to do.

On the other hand, in connection with an electric braking system of an automobile, a squirrel-cage three-phase induction machine is connected to an internal combustion engine for driving a vehicle, and an inverter circuit for applying a rotating magnetic field to a stator portion of the squirrel-cage three-phase induction machine Then, a first inverter circuit) is provided, and the rotation speed of the rotating magnetic field is controlled to a range that gives positive and negative slips to the rotation speed of the rotor portion of the cage-type three-phase induction machine. A device for operating a three-phase induction machine as a generator to give a braking force and as a motor to give an auxiliary driving force was invented, and a patent application was filed by the applicant and joint applicant (Japanese Patent Application No. 62-36278). issue).

[Problems to be solved by the invention]

In the above-mentioned conventional auxiliary power unit, since the internal combustion engine for traveling is continuously rotated during the work period, the noise associated with the work is large and the night work in the residential area cannot be performed. Further, since the output of the internal combustion engine for traveling is large as compared with the auxiliary power used, there is a drawback that the utilization efficiency of fuel is poor and the cost for output is large.

An object of the present invention is to improve this, and to provide a working AC power supply device that produces less noise during operation and has low output cost.

[Means for solving problems]

The present invention is a cage three-phase induction machine connected to an internal combustion engine,
An AC power supply device for a vehicle, comprising an inverter circuit, a battery, a converter circuit, a switching circuit, and a control circuit, the switching circuit having an input side connected to a squirrel cage three-phase induction machine or a three-phase power outlet. The output side is connected to the AC side input of the inverter circuit, the converter circuit is connected to the output side of the inverter circuit or the battery to the input side,
A three-phase electric motor is connected to the output side, and the control circuit has three control modes.In the first control mode, the inverter circuit is connected to the squirrel cage three-phase induction machine by the switching circuit, and the three-phase AC The power generation output of the converter is converted into direct current, and this direct current is converted into a three-phase alternating current by the converter circuit for output.In the second control mode, the switching circuit connects to the commercial power source via the three-phase power outlet and the commercial power is supplied. The power is converted to direct current, and the direct current is converted to three-phase alternating current by the converter circuit for output.In the third control mode, the battery output is supplied to the converter circuit and this direct current is converted to three-phase alternating current and output. It is characterized by doing.

The converter circuit can be connected to a three-phase electric motor for work power on the output side.

Also, the inverter circuit can connect the DC output to the battery.

[Action]

Rotational power for cranes, mixers, power shovels, and other work is supplied from a three-phase electric motor mounted on the vehicle. The three-phase motor is a squirrel-cage induction motor, a synchronous motor or the like.

In the first mode, the energy supplied to the three-phase electric motor is supplied from the running internal combustion engine of the vehicle to operate. At this time, the cage-type three-phase induction machine connected to the internal combustion engine is operated as a generator to generate three-phase alternating current, and this three-phase alternating current is converted into direct current by the inverter circuit, and this direct current is converted into the second inverter circuit. Is converted into alternating current again and supplied to the three-phase motor.

In the second mode, the electric power supplied to the three-phase electric motor is supplied from the commercial power supply. At this time, the AC side circuit of the inverter circuit is connected to the commercial power source by the switching circuit, and the energy obtained on the DC side is converted into three-phase AC by the converter circuit and supplied to the three-phase electric motor.

In the third mode, the electric power supplied to this three-phase electric motor is supplied from the battery mounted on the vehicle. At this time, the battery current is supplied to the DC side of the converter circuit, and the three-phase AC obtained in the AC side circuit is supplied to the three-phase electric motor.

In the first mode, the auxiliary power can be continuously used by operating the internal combustion engine of the vehicle even in a place where there is no commercial power supply. However, the rotation noise of the internal combustion engine is large.
Also, the energy cost is high.

In the second mode, the noise is low because the internal combustion engine does not rotate. The energy cost is a charge for the commercial power source and is small. However, it cannot be used except where commercial power can be taken into the car.

In the third mode, the auxiliary power can be used without operating the internal combustion engine even in a place without a commercial power source. However, since the battery capacity is finite in this third mode, continuous operation is not possible, and work is limited to a very short time. Energy costs are high.

Since the rotational power for work is obtained from the three-phase motor, it is possible to rotate in both forward and reverse directions by changing the electrical connection. Further, by controlling the AC frequency generated in the converter circuit, the rotation speed can be arbitrarily controlled.

〔Example〕

Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram for explaining the principle of a power unit for a special vehicle according to an embodiment of the present invention, and FIG. 2 is an electric circuit diagram for explaining an embodiment of the present invention.

An alternating current power supply device for a vehicle according to an embodiment of the present invention includes an internal combustion engine 1, a squirrel-cage three-phase induction machine 2 connected to the internal-combustion engine 1, and a stator portion of the squirrel-cage three-phase induction machine 2. An inverter circuit 4 for applying a magnetic field to convert the three-phase alternating current generated by the squirrel cage three-phase induction machine 2 into direct current or convert the commercial three-phase alternating current supplied via the three-phase power outlet 9 into direct current.
And a battery 5 connected to the DC side of this inverter circuit 4.
The DC circuit was connected to the battery 5, and the AC side circuit was connected to the three-phase electric motor 7 which is connected to the load 6 such as an oil pump used for a crane truck, a mixer truck, a power shovel, etc. and which operates as work power. Converter circuit 8
And a switching circuit 10 for switching and connecting the AC side circuit of the inverter circuit 4 to the squirrel cage three-phase induction machine 2 and the commercial three-phase power input from the three-phase power outlet 9 and the control of the inverter circuit 5 and the converter circuit 8. The control circuit 3 which performs is provided.

The control circuit 3 controls the rotation speed of the rotating magnetic field applied to the stator portion of the squirrel cage three-phase induction machine 2 to a range that gives positive and negative slips to the rotation speed of the rotor portion, and drives the inverter circuit 4. The converter circuit 8 is controlled so as to operate as a generator or an electric motor and to give a three-phase alternating current of a predetermined frequency to the three-phase electric motor 7.

As shown in FIG. 2, in the embodiment of the present invention, the switching circuit 10 is connected to the AC side input of the inverter circuit 4, and the DC side terminals E ₁ and E ₂ of the inverter circuit 4 are connected to the converter circuit 8. The DC side terminals E ₁ and E ₂ are connected to each other. A capacitor C ₁ , a series circuit of a switch SW and a load resistor 11 is connected to both ends of the DC side terminals E ₁ and E ₂ of these circuits.

A series circuit of a reactor L and a backflow prevention diode D ₁ is connected between the positive terminal of the battery 5 and a terminal E _1, and a collector / emitter circuit of a transistor Q ₁ is connected in parallel with the diode D ₁ . Transistor Q ₂ is between the reactor L and the diode connection point and the terminal E ₂ of the D ₁
The collector-emitter circuit of is connected, and the diode D ₂ is connected in parallel with the transistor Q ₂ . further,
A control circuit CT that receives the voltage of the terminal E _{1 and} the voltage of the positive terminal of the battery 5 is provided.

The inverter circuit 4 includes switch elements Q _a , Q _b , Q _c , Q _d , Q _e , and Q _f connected to the switching circuit 10, and these switch elements are respectively provided between the transistor and the collector / emitter of the transistor. It is composed of diodes connected in parallel in opposite directions. Further, the inverter circuit 4 includes an opening / closing control signal generating circuit PWM which gives an opening / closing control signal to the control electrodes of the respective switch elements.

This open / close control signal generation circuit PWM adds an analog signal output from the rotation sensor 12 provided in the squirrel cage three-phase induction machine 2 through the D / A converter 13 and a signal output from the control circuit 14 and inputs it. To be connected.

The converter circuit 8 includes switch elements Q _g , Q _h , Q _i , and Q connected to the three-phase electric motor 7 similarly to the inverter circuit 4.
_j, Q _k, comprises a Q _L, the switch elements is composed of a transistor, respectively, in opposite directions in parallel connected diode between the collector and emitter of the transistor. Further, the converter circuit 8 includes an opening / closing control signal generating circuit PWM which gives an opening / closing control signal to the control electrodes of the respective switch elements. This open / close control signal generation circuit PWM is connected to a clock generator 15 that controls the AC frequency. A variable resistor 16 is connected to the clock generator 15, and by operating the variable resistor 16, the generated clock frequency can be changed.

A working power unit to which the embodiment of the present invention is applied is equipped with a work power load 6 in addition to a vehicle power unit such as a crane truck, a mixer truck, and a power shovel. This power is supplied from the three-phase electric motor 7.

Next, the operation of the alternating-current power supply device of the present invention configured as described above will be described.

This device has three operation modes.

First, in the first mode, the energy supplied to the three-phase electric motor 7 is supplied from the traveling internal combustion engine 1 of the vehicle to be operated. The cage-type three-phase induction machine 2 connected to the internal combustion engine 1 is operated as a generator to generate three-phase alternating current, and the three-phase alternating current is sent to the inverter circuit 4 connected by the switching circuit 10 to be converted into direct current, This direct current is sent to the converter circuit 8 and converted again into alternating current and supplied to the three-phase electric motor 7 to supply its power to the load 6
Supply to.

The open / close control signal generation circuit PWM of the inverter circuit 4 includes
The rotation speed signal of the squirrel cage three-phase induction machine 2 detected by the rotation sensor 12 is input via the D / A converter 13, and the control signal of the control circuit 14 is added to this and input. At this time, the rotation speed of the rotating magnetic field applied to the squirrel cage three-phase induction machine 2 is lower than the rotation speed of the rotor portion, and a negative slip is applied. That is, the control circuit 14 generates a negative voltage.

Further, the switching control signal generation circuit PWM of the converter circuit 8
A control signal for controlling the AC frequency from the clock generation circuit 15 is input to the three-phase electric motor 7.

In this mode, the squirrel cage three-phase induction machine 2 operates as a generator. At this time, the control circuit CT selects the terminal _Br ,
Given repetition pulse to the control input terminal B _r of the transistor Q _1, the transistor Q ₁ is intermittently conductive. As a result, the closed loop of the capacitor C ₁ (terminals E ₁ and E ₂ ), the capacitor C ₂ , the reactor L and the transistor Q ₁ is intermittently closed, and energy is stored in the reactor L. When the terminal voltage of the reactor L becomes higher than the terminal voltage of the battery 5, a closed loop is formed in the reactor L, the battery 5, and the diode D ₂ , and a current flows and the battery 5
Is charged. The terminal voltage of the battery 5, that is, the terminal voltage of the capacitor C ₂ is compared with the reference voltage applied to the control circuit CT by the control circuit CT, and its pulse width and repetition period are adjusted so that the terminal voltage falls within a predetermined range. Is adjusted.

In this first mode, the three-phase electric motor 7, which is the auxiliary power, can be continuously driven by operating the internal combustion engine 1 of the vehicle even in a place where there is no commercial power source. Is large and the energy cost is large.

In the second mode, the switching circuit 10 has a three-phase power outlet 9
The three-phase electric motor 7 is supplied with electric power from a commercial power source. At this time, the squirrel cage three-phase induction machine 2 is disconnected and the internal combustion engine 1 can be stopped. At this time, the AC side circuit of the inverter circuit 4 is connected to a commercial power source, and the energy obtained on the DC side thereof is converted into a three-phase AC by the converter circuit 8 and supplied to the three-phase electric motor 7, and the load 6
Is powered by. Other operations are the same as those in the first mode.

In this mode, the internal combustion engine 1 is stopped or has no load, so that the noise is low and the energy cost is low because the charge of the commercial power source is sufficient. However, it cannot be used except where there is a facility that can supply commercial power to an automobile.

In the third mode, electric power supplied to the three-phase electric motor 7 is obtained from the battery 5 mounted on the vehicle. In this case, the current of the battery 5 is supplied to the DC side of the converter circuit 8, and the three-phase AC obtained in this AC circuit is supplied to the three-phase electric motor 7.
The load 6 is powered.

At this time, the control circuit CT selects the terminal D _r and gives an intermittent signal to the control electrode of the transistor Q ₂ . As a result, a current flows through the loop of the battery 5, the reactor L, and the transistor Q ₂ for a short time, and energy is stored in the reactor L. At the next moment, the transistor Q ₂ is opened, and the sum of the terminal voltage of the reactor L and the terminal voltage of the battery 5 appears across the capacitor C ₁ via the diode D ₂ . The voltage across the capacitor C ₁ serves as a DC power source for the converter circuit 8.

In the third mode, auxiliary power can be obtained without operating the internal combustion engine 1 even in a place where there is no commercial power source, but continuous operation is impossible because the battery capacity is limited. , The energy cost will be higher.

In the device of the present invention, since the rotary power for work is obtained from the three-phase electric motor 7 in any mode, the switching control signal generating circuit P
By changing the output signal generation order of the WM, the rotation direction can be set to both the forward and reverse directions.
By controlling the variable resistor 16 with respect to the AC frequency generated at 1, the rotation speed of the three-phase electric motor 7 can be arbitrarily controlled.

Although each of the above-described embodiments has been described using the transistor as the switch element, the present invention can be similarly implemented by using other switch elements such as a thyristor and a GTO.

〔The invention's effect〕

As described above, according to the present invention, work power can be obtained in the following three modes as a work power device for a crane truck, a mixer truck, a power shovel, and the like.

1. A squirrel-cage three-phase induction machine is operated as a generator by an internal combustion engine for running, and its three-phase alternating current is supplied to a three-phase motor.

2. Supply the three-phase alternating current from the commercial power source to the three-phase motor as a power source.

3. Three-phase alternating current is supplied to the three-phase electric motor from the battery installed in the vehicle.

Furthermore, in the first mode, it can be used continuously in places where there may be noise due to work or in places where there is no commercial power source, and in the second mode, operation noise is small, so work in the residential area, In particular, it can be used for night work, and its energy cost is low, and in the third mode, it can be used in places where there is no commercial power source or when short-time operation is sufficient. These three modes can be freely selected according to the situation of the work site.

In addition, since rotation power for work is obtained from the three-phase electric motor in either mode, it is possible to obtain rotation in both the forward and reverse directions by switching the electrical connection, and the AC frequency to the three-phase electric motor can be obtained. Since it can be controlled, there are many excellent effects such that the rotation speed can be arbitrarily controlled in a wide range.

[Brief description of drawings]

FIG. 1 is a block diagram showing the principle of a power unit for a special vehicle according to an embodiment of the present invention. FIG. 2 is an electric circuit diagram for explaining an embodiment of the present invention. 1 ... Internal combustion engine, 2 ... Cage-shaped three-phase induction machine, 3, 14 ...
Control circuit, 4 ... Inverter circuit, 5 ... Battery, 6 ...
Load, 7 ... Three-phase motor, 8 ... Converter circuit, 9 ...
… Three-phase power outlet, 10 …… Switching circuit, 11 …… Load resistance, 12 …… Rotation sensor, 13 …… DA converter, 15 …… Clock generator, 16 …… Variable resistor.

Claims (3)

[Claims] 1. A cage-type three-phase induction machine (2) connected to an internal combustion engine (1), an inverter circuit (4), and a battery (5).
An AC power supply apparatus for a vehicle, comprising: a converter circuit (8); a switching circuit (10); and a control circuit (3), wherein the switching circuit (10) has a squirrel-cage three-phase induction machine on the input side. Alternatively, the output side is connected to the AC side input of the inverter circuit (4), and the converter circuit (8) is connected to the output of the inverter circuit or the battery (5). , A three-phase electric motor (7) is connected to the output side, and the control circuit (3) has three control modes. In the first control mode, the switching circuit (10) causes the inverter circuit (4) to drive the car. Form three-phase induction machine (2),
The generated output of the three-phase alternating current is converted into direct current, and this direct current is converted into three-phase alternating current by the converter circuit (8) for output. In the second control mode, the three-phase power outlet ( 9) is connected to a commercial power source to convert the commercial power into direct current, and the direct current is converted into a three-phase alternating current by the converter circuit (8) for output. In the third control mode, the converter circuit (8) is used. An AC power supply device for automobiles, which supplies the output of the battery (5) to, and converts this DC into three-phase AC for output. 2. The working AC power supply device for an automobile according to claim 1, wherein the converter circuit (8) has a three-phase electric motor (7) for working power connected to the output side. 3. The AC power supply device for a vehicle according to claim 1, wherein the inverter circuit (4) has a DC output connected to a battery.