JPH05146007A - Control circuit for vehicle driver - Google Patents

Abstract

PURPOSE:To enhance comfortableness by preventing motor torque, on the side of non-idling wheel, from lowering even when the feeder voltage is low thereby suppressing variation of acceleration when the capacitor voltages on the input side of inverters are balanced at the time of idling or slippage of wheel. CONSTITUTION:Voltages V1, V2 of parallel capacitors in two series connected inverters are fed to an average value operating circuit 201 in order to determine an average capacitor voltage. Thus determined average voltage is then fed to a set voltage operating circuit 202. In the operating circuit 202, the average voltage is added with bias voltages VX, VY to produce first and second set voltages Vr1, Vr2. The set voltages Vr1, Vr2 are then compared with the capacitor voltages V1, V2 thus producing signals for turning a corresponding chopper ON/OFF upon occurrence of idling or slippage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control circuit for a vehicle drive device, and more particularly, to a vehicle drive device in which a plurality of inverters are connected in multiple stages in series and a train is driven by a motor connected to each inverter, The present invention relates to a control circuit that controls so as to maintain the voltage balance of a filter capacitor when a wheel slips or skids.

[0002]

2. Description of the Related Art FIG. 3 shows a circuit configuration of a vehicle drive device constituted by a multi-stage series inverter. In this figure, in order to simplify the description, the case where a two-stage series inverter is used is shown. In the figure, 1 is a train line,
2 is a pantograph, 3 is a reactor for filters, 41,
42 is an inverter such as a voltage-type PWM inverter connected in series, 51 and 52 are filter capacitors connected in parallel to the respective inverters 41 and 42 to equally divide the input voltage, 71 and 72 are choppers composed of transistors and the like,
81 and 82 are resistors connected in series to these choppers 71 and 72, 9 is a wheel, 10 is a rail, 61,
Reference numeral 62 is a motor driven by each inverter 41, 42. Wheels are coupled to the output shafts of the motors 61 and 62 via a mechanical system such as a gear (not shown).

In the above-described vehicle drive device, when the wheel spins or slides to reduce the load on one motor 61, for example, the output current of the corresponding inverter 41 decreases and re-adhesion between the wheel and the rail is achieved. Therefore, the torque of the motor 61 is reduced. If only the output current of one inverter 41 decreases in this way, the voltages of the capacitors 51 and 52, which divide the input voltage, become unbalanced, which may cause the inverter 41 to malfunction due to overvoltage. Therefore, in the vehicle drive device of FIG.
The change in the voltage of the capacitors 51 and 52 due to the decrease in the output current is detected, and the chopper 71 is turned on / off according to the change in the output current, so that the decrease in current is passed to the series resistor 81. The current value flowing through this resistor 81 is the chopper 71.
It can be adjusted by changing the on / off ratio of. That is, conventionally, the difference in the input power of the two inverters 41 and 42 is consumed by the chopper 71 and the resistor 81 or the chopper 72 and the resistor 82 to maintain the voltage balance of the capacitors 51 and 52.

Therefore, by performing the above-mentioned control by the chopper 71 or 72 on the side where the load is reduced, the voltages of the capacitors 51 and 52 are balanced even if the loads of the inverters 41 and 42 are unbalanced. Can be made As a concrete control circuit thereof, in FIG. 3, on / off control circuits 111 and 112 are provided corresponding to the choppers 71 and 72, and the base drive circuits 101 and 102 are connected to the output side thereof. Then, the voltages V1 and V2 of the capacitors 51 and 52 are input to the on / off control circuits 111 and 112, respectively, and the first and second
Of the voltage setting values Vr ₁ and Vr ₂ (Vr ₁ > Vr ₂ ) of the control circuit 11
Input to both 1 and 112.

With this control circuit, for example, the capacitor 5
When the voltage V1 of ₁ becomes higher than the voltage setting value Vr _1, it is determined that the capacitor 51 is in the overvoltage state, and the control circuit 111
Outputs a signal to turn on the chopper 71, and the base drive circuit 101 turns on the transistor in the chopper 71 to cause a current to flow through the resistor 81. This operation is the same for the control circuit 112 for taking in the voltage V2 and the voltage setting value Vr ₁ of the other capacitor 52. On the other hand, when the voltage V1 of the capacitor 51 becomes lower than the voltage set value Vr _2,
A signal for turning off the chopper 71 is output from the control circuit 111, and the base drive circuit 101 turns off the transistor in the chopper 71 to cut off the current. This operation is the same for the control circuit 112 for taking in the voltage V2 and the voltage setting value Vr ₂ of the other capacitor 52. The relationship between these voltage setting values Vr ₁ and Vr ₂ and the operation of the choppers 71 and 72 is shown in FIG.

Next, an example of the case where the chopper operates due to the idling of the wheels will be described with reference to FIG. However, for convenience of explanation, a current reduction (current throttling) pattern during idling,
The startup pattern was rectangular. Now, at time t _{1 in} FIG.
When the wheel corresponding to the inverter 41 idles at
This is detected by the number of rotations of the motor 61, etc., and the output current of the inverter 41 is narrowed down so that the input current becomes as shown in FIG. Due to this decrease in the input current, the voltage V1 of the capacitor 51 rises, and when it exceeds the set value Vr ₁ , the chopper 71 is turned on as described above. As a result, the resistor 81
Through which the discharge current of the capacitor 51 flows, and its voltage V
1 begins to drop. Then, the voltage V1 chopper 71 is turned off when the voltage V1 is smaller than the set value Vr ₂ begins to rise again. This operation is performed at time t _{2 as} shown in FIG.
The process is repeated until the idling control is completed at. The voltage V2 of the capacitor 52 during this period has a value such that the sum of the voltage V1 and the voltage V1 is always a constant value equal to the train line voltage.

[0007]

The fluctuation range of the electric line voltage is generally large, and in the case of a direct current 1500 [V] feeding system, the electric line voltage is as high as 1000 to 2000 [V]. Chopper 7 in normal conditions other than idling and sliding
In order to prevent 1 and 72 from operating, the voltage setting value Vr ₁
Must be determined so as to satisfy the following equation in relation to the maximum value of the train line voltage. Here the voltage setting value _{Vr 1> Vsmax / 2 + α} , Vsmax the maximum value of the catenary voltage, alpha is Vr ₁ -Vr
_It is the hysteresis width represented by ₂ , and from this equation,
Vr ₁ must be set to 1000 + α [V] or higher.

However, when Vr ₁ has a relatively high value as described above but the train line voltage is low, the wheels corresponding to the inverter 41 idle and the chopper 71 is controlled as described above. And during the time t ₁ to t ₂ when this control is performed, the voltage V1 of the capacitor 51 is
6 has a relatively high value between Vr ₁ and Vr ₂ as shown in FIG. 6, the voltage V2 of the capacitor 52, which is the difference between the line voltage and this voltage V1, is a low value as shown in the figure. turn into. That is, the input capacitor voltage of the inverter 42 corresponding to the wheel in which the idling does not occur decreases, and the motor torque decreases sharply. In an extreme case, if the power line voltage drops to 1000 [V],
The voltage V2 of the capacitor 52 becomes zero and the motor torque also becomes zero.

As a result, when the idling occurs, the torque of the two motors is reduced, so that the acceleration is drastically reduced, and a sudden change in the acceleration causes a back-and-forth movement of the vehicle, resulting in a bad riding comfort. The present invention has been made to solve the above problems, and an object of the present invention is to prevent slipping or the like even if a train line voltage is reduced when a wheel slips or slides. It is an object of the present invention to provide a vehicle drive device that prevents a reduction in motor torque corresponding to wheels and improves ride comfort.

[0010]

In order to achieve the above object, the present invention provides a plurality of inverters, each of which has a motor for driving a vehicle connected to the AC side, connected in series in multiple stages, and the inverter is connected to the inverter. The filter capacitors are respectively connected in parallel, and the series circuits of the chopper and the resistor are respectively connected in parallel to these filter capacitors, and when the voltage of the capacitors becomes higher than the first voltage setting value, the capacitors are concerned. Side chopper is turned on to reduce the voltage of the capacitor, and when the voltage of the capacitor is lower than a second voltage setting value lower than the first voltage setting value, the capacitor side chopper is turned off. In the control circuit of the vehicle drive device that controls
It is provided with a voltage setting means for setting the first and second voltage set values high when the electric line voltage is high and low when the electric line voltage is low.

The voltage setting means adds an average value calculation circuit for obtaining an average value of the voltages of the plurality of filter capacitors and a constant ON operation bias voltage to the average value to obtain a first voltage setting value. It is preferable to be configured by a voltage setting value calculation circuit that obtains the second voltage setting value by adding a constant OFF operation bias voltage to the average value.

[0012]

According to the present invention, idling or the like occurs by changing the first and second voltage setting values, which are the threshold values for turning on and off the chopper, in accordance with the fluctuation of the power line voltage. It acts so as to reduce the difference between the voltage of the capacitor on the charging side and the voltage of another capacitor (the capacitor on the side on which no idling etc. has occurred) connected in series to this. Therefore, even if the train line voltage is low, it is possible to prevent the voltage drop of the capacitor on the side where idling does not occur, and to prevent the reduction of the motor torque driven by the inverter using this capacitor voltage as the input voltage. It is possible to improve the ride comfort by continuing to accelerate the vehicle.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. Since the control circuit according to the present invention is applied to the vehicle drive device having the configuration shown in FIG. 3, the description will be given below with reference to the components and reference numerals of FIG. 3 as necessary. First, FIG. 1 shows a main part of this embodiment. In FIG. 1, reference numeral 300 designates first and second voltage setting values Vr _{1 which} are threshold values for turning on and off the choppers 71 and 72. , Vr ₂ is a voltage setting means for setting Vr ₂ according to the fluctuation of the train line voltage. In the setting means 300, 201 is an average value calculation circuit, and this calculation circuit 20
1 is the voltage V1 of the capacitors 51 and 52 in FIG.
V2 is input, and the average value of these is calculated and output.

The capacitor average voltage output from the arithmetic circuit 201 is input to the voltage set value arithmetic circuit 202. This arithmetic circuit 202 has a first and second voltage setting value V which is compared with the voltages V1 and V2 of the capacitors 51 and 52.
is a circuit for calculating r ₁ and Vr ₂ , and is a bias voltage V for ON operation which is input separately with respect to the average voltage of the capacitor.
_The voltage setting values Vr ₁ and Vr ₂ are calculated by adding _X and the OFF operation bias voltage V _Y , respectively.

Next, this operation will be described with reference to FIG. As described above, since the average value calculation circuit 201 obtains the average value of the voltages V1 and V2 of the capacitors 51 and 52, it is assumed that the wheels on the inverter 41 side idle and the voltage V
1 rises and the voltage V2 falls relatively, the voltage V
As long as there is no change in the sum of 1 and V2, the average value calculation circuit 20
The same voltage value is always output from 1.

For example, when the train line voltage is high and the average value of the capacitor voltage is also high as indicated by V _B in FIG. 2, the voltage setting value calculation circuit 202 sets this voltage V _B to the ON operation bias voltage V _X and OFF. The operation bias voltages V _Y are added to calculate the voltage set values Vr ₁ and Vr ₂ . As a result, the chopper 71 on the inverter 41 side causes the capacitor voltage V1 to change to the first voltage setting value V by the operation of the on / off control circuit 111 and the base drive circuit 101 shown in FIG.
When it becomes higher than r ₁ , it is turned on to lower the voltage V 1,
When the voltage becomes lower than the voltage setting value Vr _{2 of} the above, it is controlled to turn off. At this time, the voltage V2 of the other capacitor 52
Takes a value between V _B -V _X and V _B -V _Y.

Further, when the train line voltage is low and the average value of the capacitor voltage is also low as indicated by V _A in FIG. 2, the voltage setting value calculation circuit 202 sets this voltage V _A to the ON operation bias voltage V _X and the OFF voltage. The operation bias voltages V _Y are added to calculate the voltage set values Vr ₁ and Vr ₂ . This allows
Similarly to the above, the chopper 71 on the side of the inverter 41 is controlled so as to turn on when the capacitor voltage V1 becomes higher than Vr ₁ and lower the voltage V1 and turn off when it becomes lower than Vr ₂ . At this time, the voltage V2 of the other capacitor 52 is
It takes a value between V _A -V _X and V _A -V _Y.

That is, according to this embodiment, the voltage set values Vr ₁ and Vr ₂ are changed according to the level of the electric line voltage, so that the voltages V1 and V2 of the two capacitors 51 and 52 are changed.
Is controlled to a voltage within a certain range such that there is a maximum difference of 2V _X around these average values (for example, V _A and V _B ). Therefore, when the train line voltage is low, there is no inconvenience that the voltage of the capacitor corresponding to the wheel in which the idling does not occur is greatly reduced and the motor torque is drastically reduced. As a result, the vehicle that is not spinning or slipping continues to accelerate the vehicle, so that the riding comfort can be improved as compared with the conventional case.

In the above embodiment, each capacitor 51,
The voltages V1 and V2 of 52 are input to the arithmetic circuit 201 and the average value thereof is calculated.
A method of calculating the average value by inputting the added value of 1 and V2 may be used. Further, although the case where the series inverter has a two-stage configuration has been described in the above embodiment, the present invention can be similarly applied even if the number of series stages is increased.

[0020]

As described above, according to the present invention, even if the power line voltage fluctuates, the voltage value of each filter capacitor during idling or sliding is maintained within a certain range, and idling does not occur. It is possible to avoid a situation in which the voltage of some capacitors corresponding to the wheels drops significantly. For this reason, it is possible to prevent a decrease in the torque of the motor corresponding to the capacitor-side inverter, suppress a change in the acceleration of the vehicle to a small extent, and significantly improve the riding comfort.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main part of an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a capacitor voltage and a chopper operation in the embodiment of FIG.

FIG. 3 is a circuit configuration diagram of a main part of a vehicle drive device to which the embodiment of FIG. 1 is applied.

FIG. 4 is a diagram showing a relationship between a capacitor voltage and a chopper operation.

FIG. 5 is an explanatory diagram of an inverter input current and a capacitor voltage when idling occurs.

FIG. 6 is an explanatory diagram of an inverter input current and a capacitor voltage when idling occurs when the train line voltage is low.

[Explanation of symbols]

 41,42 Inverter 51,52 Filter capacitor 61,62 Motor 71,72 Chopper 81,82 Resistor 101,102 Base drive circuit 111,112 On / off control circuit 201 Average value calculation circuit 202 Voltage setting value calculation circuit 300 Voltage setting means

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kazunori Hasebe 1-6-5 Marunouchi, Chiyoda-ku, Tokyo East Japan Railway Company (72) Inventor ▲ Haruyuki Kawa ▼ Shin Tanabe, Kawasaki-ku, Kawasaki-shi, Kanagawa No. 1 No. 1 in Fuji Electric Co., Ltd. (72) Inventor Michio Iwahori No. 1 Tanabe Nitta, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture No. 1 within Fuji Electric Co., Ltd. (72) Naoto Yoshinori Shin Tanabe, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture No. 1 No. 1 within Fuji Electric Co., Ltd. (72) Inventor Hiroaki Tamura No. 1 No. 1 Nitta Tanabe, Kawasaki-ku, Kawasaki-shi, Kanagawa Inside Fuji Electric Co., Ltd.

Claims (2)

[Claims] 1. A plurality of inverters each having a motor for driving a vehicle connected to an alternating current side are connected in series in multiple stages, and filter capacitors are respectively connected in parallel to the inverters, and these filter capacitors are also connected. A series circuit of a chopper and a resistor is respectively connected in parallel, and when the voltage of the capacitor becomes higher than a first voltage setting value, the chopper on the capacitor side is turned on to reduce the voltage of the capacitor, In the control circuit of the vehicle drive device, which controls to turn off the chopper on the side of the capacitor when the voltage of the capacitor becomes lower than the second voltage setting value which is lower than the first voltage setting value, And a voltage setting means for setting the second voltage set value high when the train line voltage is high and low when the train line voltage is low. The control circuit of the vehicle drive unit, characterized in that. 2. A voltage setting means calculates an average value of voltages of a plurality of filter capacitors, and an average value calculation circuit for adding a constant ON operation bias voltage to the average value to obtain a first voltage setting value. 2. A control circuit for a vehicle drive device according to claim 1, further comprising a voltage setting value calculation circuit for adding a constant off-operation bias voltage to the average value to obtain a second voltage setting value.