JPH0118675B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shunt motor control device using a microcomputer, and particularly to a shunt motor control device suitable for use in an electric vehicle.

When a shunt motor is controlled by a chopper circuit, it has two chopper circuits, an armature chopper circuit and a field chopper circuit, as disclosed in Japanese Unexamined Patent Publication No. 157821/1982. By the way, the period of the armature chopper is generally changed according to the conduction rate of the chopper in order to keep the pulsation of the armature current constant. On the other hand, since the inductance of the field winding is large, the current ripple is small and is controlled at a constant cycle.

When such two choppers are controlled by a microcomputer, conventionally, interrupt pulses are provided at fixed time intervals for controlling the armature chopper circuit and interrupt pulses at fixed time intervals for controlling the field chopper circuit. Each had an independent interrupt processing program to perform control processing. In this case, the interrupt processing program becomes complicated, and generally generates interrupt pulses at a faster rate than the chopper cycle, which occupies much of the microcomputer's processing time, leaving time for other processes to be executed. was decreasing.

An object of the present invention is to simplify the interrupt processing of a microcomputer by synchronizing the operation of the armature chopper circuit and the field chopper circuit.

A feature of the present invention is that an interrupt pulse is generated in the microcomputer in synchronization with the operation of the armature chopper circuit, and the operation of the field chopper circuit is also synchronized with the operation of the armature chopper.

Embodiments of the present invention will be explained with reference to FIG. 1 and subsequent figures.
FIG. 1 is a basic configuration diagram of an electric vehicle control device according to an embodiment of the present invention. Reference numeral 1 designates a microcomputer, which includes a microprocessor 2, a random access memory 3, a read-only memory 4, an oscillator 5, and a bus line 6 for address, data, and control. 7 is an analog input circuit,
Analog electric signals ACA and BRA corresponding to the amount of depression of the accelerator device 8 and brake device 9, respectively.
FIG. 2 shows an embodiment of the circuit which converts the operating state detection signal of the main circuit 10 and a plurality of analog signals obtained through the level conversion circuit 11 into digital signals and takes them in. Level conversion circuit 11
is composed of six circuits, including an amplifier 101 that amplifies the output IM of the armature current detector, an amplifier 102 that amplifies the output IF of the field current detector,
An amplifier 103 that amplifies the output TB of the battery temperature detector, an amplifier 104 that amplifies the output TM of the motor temperature detector, and an amplifier 105 that detects the temperature of the main thyristor of the main circuit 10 and amplifies its output signal TT. and a voltage divider circuit 106 that lowers the battery voltage VB to a low voltage. Further, the analog input circuit 7 is an analog multiplexer 10.
7, an A/D converter 108, a register 109, and an analog input control circuit 110. Now, when a signal is given from the microprocessor 2 to the AIC shown in FIG. 2, the analog input control circuit 110 operates the multiplexer 107 to connect the analog input specified by the AIC to the A/D converter 108. . Then, the A/D converter 108 is activated, the specified analog quantity is converted into a digital quantity, and a data value corresponding to the converted quantity is held in the register 109. As a result, the microprocessor 2 can take in the specified analog amount by reading the AI value.

12 is a digital input circuit, which includes a 1-bit accelerator switch signal ACD from the accelerator device 8 that indicates that the accelerator pedal has been depressed;
1-bit brake switch signal from brake device 9 indicating that the brake pedal has been depressed
BRD and the signal KSD from the key switch 13 are taken in, and the signal is converted by the circuit shown in FIG. 3 to be input to the microcomputer.

The digital input circuit 12 includes resistors R ₁ , R ₃ , and resistors connected to the power supply of the microcomputer 1.
R ₅ and the resistors R ₂ , R ₄ , which constitute the first-order lag filter,
It consists of R ₆ , capacitors C ₁ , C ₂ , and C ₃ . Now, when the switch SWA of the accelerator device 8 is open, the digital input signal DIA of the microcomputer 1 becomes the power supply voltage Vcc. Further, when the accelerator switch SWA is closed, DIA becomes 0 [V]. Note that the filter consisting of resistor R ₂ and capacitor C ₁ is for noise prevention. Similarly, when brake switch SWB and key switch SWK operate,
Other digital input signals DIB, depending on its operation
DIK becomes the power supply voltage Vcc or 0 [V].

The interrupt circuit 14 has a configuration as shown in FIG. In the example shown in FIG. 4, the circuit receives interrupt pulses INP1 to INP4 from four sources. Now, when a pulse is generated at INP1, the flip-flop circuit 11 is set and the output becomes the IND1 level. On the other hand, interrupt pulse INP1 is OR circuit 1
15, and provides an interrupt pulse INT to the microprocessor 2. As a result, microprocessor 2 imports the contents of IND and
Generates reset pulse INRE for flip-flops 111-114. Then, the contents of IND are checked, and if IND1 is at the "1" level, it is assumed that an interrupt has occurred in that part, and the interrupt processing is executed. The same applies when an interrupt pulse is input to INP2 to INP4. Returning to FIG. 1, 15 is a conduction rate control circuit for the armature chopper and field chopper, and the two square waves of this output are sent to the pulse distribution circuit 1.
6, the armature chopper is divided into on-pulse and off-pulse. These pulse signals are amplified by the amplifier circuit 17 and become control signals for the chopper in the main circuit 10. Figure 5 shows the details of this part of the circuit, and part of its operating waveforms are shown in Figure 6.
As shown in the figure. The conduction rate control circuit 15 includes a first counter 400, a second counter 401, a first register 403, a second register 404, a third register 405, a first digital comparator 406, and a second
digital 407, third digital comparator 4
Consists of 08. The counter 400 counts the clock pulses CLO produced by the oscillator 5. As a result, the output COUI of the counter 400 increases as shown in FIG.
Then, in the first digital comparator 406, the
Pulse CL1 is generated when DCT and COU1 match. This pulse becomes the reset pulse for the first counter 400 and the clock pulse for the second counter 401. Now clock pulse CLO
When the frequency of is (Hz), the pulse interval ΔT of CL1 is expressed by the following equation using the value Nc of DCT.

△T=N _c・ ...(1) From equation (1), the pulse period △T of CL1 is the value of DCT
It can be seen that it changes in proportion to N _c . That is, N _c
The frequency of CL1 can be changed by

The pulse thus obtained becomes the clock pulse for the N-bit second counter 401.
As a result, the second counter 401 is reset every time it counts ^2N pulses, resulting in a waveform as shown in FIG. 6b. The overflow pulse of this counter becomes INP1, which becomes the interrupt pulse shown in FIG. 4, and interrupts the microprocessor 2.

On the other hand, the output value COU2 of the second counter 401
becomes an input to the second digital comparator 407 and the third digital comparator 408.

The respective output signals AP and FP of the second digital comparator 407 and the third digital comparator 408
generates a “1” level signal in synchronization with the interrupt pulse INP1 generated by the second counter 401. Then, as shown in FIG. 6b, the output value COU2 of the second counter 401 increases, and the output values N _a ,
are compared with N _f respectively.

As a result, the data held in the second register 404
The value Na of DUA is the value COU of the second counter 401
When the value is greater than 2, the output signal AP of the digital comparator 407 is output as "0".

Similarly held in the third register 405
The value N _f of DUF is the value COU2 of the second counter 401
When the value is larger than that, the output signal FP of the digital comparator 408 is outputted as "0". Regarding the square wave signals AP and FP obtained in this way, their period T _c and conduction rate α _a , α _f (time at 1 level/
T _c ) is determined by the following formula.

T _c = △T・2 ^N = N _c・・2 ^N ……(2) α _a ＝N _a・△T／T _c = N _a ／2 ^N ……(3) α _f ＝N _f・△T /T _c = N _f /2 ^N ...(4) In this way, the chopper period T _c is the register 40.
According to the value N _c of 3, that is, the value of DCT, the current flow rate α _a of the armature chopper is determined by the value N _a of register 404, that is, the value of DCT.
Depending on the value of DUA, the current flow rate of the field chopper α _f
is controlled by the value N _f of register 405, that is, the value of DUF.

The pulse distribution circuit 16 shown in FIG. 1 is constructed as shown in FIG. A monostable circuit 122 that generates a constant width pulse in synchronization with the rising edge of the output square wave of the digital comparator 407, a monostable circuit 123 that generates a constant width pulse in synchronization with the falling edge of the output square wave, and two AND gate circuits 124. , 125. One input of the AND gate circuits 124 and 125
SUP is performed by setting this signal to the "0" level when the microcomputer 2 stops generating pulses. Now SUP is “1”
When the level is reached, the monostable circuit 122,
The output of 123 is sent directly to AND gate circuit 12
The output is 4,125, and the APO and APF in Figure 6
The signal will be as follows. The AND gate circuit 12
The output of 4,125 is a pulse amplifier 126,127
The gate pulses for turning on the thyristor chopper for armature current control, which will be described later, are amplified by
APGO becomes the off gate pulse APGF. or,
The output square wave of digital comparator 408 is output to amplifier 1.
28, and becomes a base drive signal FPB of a field current control transistor chopper, which will be described later. The main circuit 10 has the configuration shown in FIG. A battery 130 is used as a power source, a thyristor chopper circuit 131 controls the armature current of a shunt motor 132, and a transistor chopper circuit 133
controls the current flowing through the field winding 134 of the shunt motor 132. Also, the thyristor chopper circuit 131
are the main thyristor 135, the auxiliary thyristor 136,
It consists of a diode 137, a commutating capacitor 138, and a commutating reactor 139. The commutating capacitor 138 includes an auxiliary charging diode 140 and a resistor 1.
41 is connected. Furthermore, 142 is a flywheel diode for the shunt motor 132 and the DC reactor 144. Furthermore, 143 is a flywheel diode for the field winding. 145 is a power supply/disconnection switch, which is turned on with a manual lever installed in the driver's seat, and the signal is turned on.
Pull it open with a FET. 146A and 146B are the contact points of the contactor, and the contactor control signal
When CON is at 0 level, the state shown in Figure 7 is reached, and when the contactor excitation signal CON is at "1" level, each contact operates, terminal CA is connected to CAM, and other terminals are connected to CAM.
CB is connected to CBM. This contactor 14
6, switching between power running and regeneration is performed. That is, the state shown in FIG. 7 indicates the regeneration mode, and when the thyristor chopper circuit 131 is turned on, the induced voltage of the shunt motor 132 is increased to the DC reactor 1.
44 and is turned off after a certain period of time, the induced voltage in the shunt motor 132 and DC reactor 144 is regenerated to the battery 130 via the flywheel diode 142. During this time, the field current is controlled by the chopper circuit 133. In this way, regeneration operation is performed. On the other hand, when the contactor excitation signal CON reaches the "1" level and the contactor 146 operates, the terminals CA and COM are connected again.
CB and CBM are connected. When the thyristor chopper circuit 131 is turned on in this state, the voltage of the battery 130 is applied to the shunt motor 132, and the current flowing through the shunt motor 132 increases. Further, when the thyristor chopper circuit 131 is turned off, the current flowing through the shunt motor 132 is attenuated through the DC reactor 144 and the flywheel diode 142, and a powering operation is performed.

Note that 147 and 148 are fuses for protection. Further, 149 and 150 are a shunt resistor for armature current detection and a shunt resistor for field current detection, respectively, and are connected to the amplifiers 101 and 10 in FIG.
The value is taken into the microcomputer 1 via the microcomputer 2. 151, 152, and 153 are thermistors that detect the temperatures of the battery 130, the main thyristor 135, and the shunt motor 132, respectively, and the amplifiers 103, 104, and 1 of FIG.
The value is taken into the microcomputer 1 via the microcomputer 05.

Returning to FIG. 1, 18 is a power digital output circuit, which generates a signal SUP for suppressing the gate pulse shown in FIG. 5, and excitation signals CON and FFT for the contactor 146 and switch 145 shown in FIG. do.

19 is a speed detection circuit, and a shunt motor 132
The speed is digitally detected based on the output pulse train PLP of the pulse generator 20 which generates pulses proportional to the speed of the motor, and is input into the microcomputer 1.

An embodiment of the speed detection circuit is shown in FIG. The counter 155 generates pulses at time intervals that serve as a reference for measuring speed. The monostable 156 generates a pulse of a constant width in synchronization with the fall of the overflow pulse of the counter 155. The counter 157 is the output pulse of the pulse generator 20.
This is for counting PLP. register 1
Reference numeral 58 is for holding the output of the counter 157 at regular intervals. Since the counter 157 is reset at fixed time intervals by the output pulses of the monostable circuit 156, the speed is detected from the number of pulses that have arrived at a fixed time, that is, the output of the counter. Note that the output of the counter is set in the register 158 by the overflow pulse of the counter 155 immediately before the reset pulse is input. The microcomputer 1 can detect the speed by reading the contents of this register 158. Note that the clock pulse of the counter 155 uses the reference pulse CLO of the oscillator 5 shown in FIG.

Returning to FIG. 1 again, 21 is a digital output circuit, which is provided to light up a lamp on a panel 22 provided at the driver's seat.

All operations of the control device shown in FIG. 1 are performed by sequentially processing the contents of the program written in the read-only memory 4. The details of this process will be explained below.

There are roughly two types of programs written in the read-only memory 4 shown in FIG. The first program is a MAIN program that is constantly executed, and its processing contents are shown in FIG.
The second program is an INT program that is activated by the generation of an interrupt pulse, and its processing contents are shown in FIG. 9 and 10 will be explained in relation to FIG. 1.

When the power is turned on to the microcomputer 1, the process of step 200 in FIG. 9 is first performed to set initial values of each register and the random access memory 3 shown in FIG. Next, the key switch signal KSD, accelerator switch signal ACD, and brake switch signal BRD are taken in via the digital input circuit 12, and a key switch determination is made in step 201. If the key switch is off, step 2
Specify a stop by performing the process of 02,
Return to key switch judgment. When the key switch is turned on, the state of the accelerator switch is checked in step 203. When the accelerator is depressed, the power running mode is specified in step 204, and at the same time, via the analog input circuit 7,
The analog output ACA of the accelerator device 8 is taken in.
On the other hand, when the accelerator switch is in the off state, the state of the brake switch is determined in step 205. When the brake switch is off, a stop is designated and the process returns to step 202. When the brake switch is on, the regeneration mode is specified in step 205, and the analog output BRA of the brake device 9 is taken in via the analog input circuit 7.

Next, in step 208, the values of the temperatures TM, TT, and TB of the motor, main thyristor, and battery are taken in via the level conversion circuit 11 and analog input circuit 7, and if the values are abnormal, the process moves to step 209, where the current A protective operation is performed to reduce the command, and an alarm is displayed on a lamp on the panel 21 via the digital output circuit 20.

Further, in step 211, the level conversion circuit 11,
The battery voltage VB is taken in through the analog input circuit 7. If the battery voltage is too low to continue operating the electric vehicle, an abnormality is determined in step 212, and steps 209 and 2 are performed.
10 protection and alarm display. Next, in step 213, the rotational speed of the electric motor is acquired via the speed detection circuit 19. If this rotational speed is abnormally high, it is determined in step 214 that overspeeding has occurred, and protection and warning display are performed. If the engine is not over-speeding, it operates normally and issues armature current commands and field current commands based on the accelerator pedal depression amount, brake pedal depression amount, and motor rotation speed detected in steps 215 and 216. The calculation is performed and the process returns to step 201. This kind of operation is executed repeatedly in the MAIN program.

If the interrupt pulse shown at INP1 in Figure 5 is input while such a MAIN program is being executed, the first
Execute the INT program shown in Figure 0. In the INT program, it is first determined whether a stop specification has been made. When specifying stop, step 302
The process moves on to output the numerical value N _c determining the chopper period T _c to the register 403 in FIG. 5 as DCT. The counter 401 sets the chopper cycle _Tc when the chopper operation is stopped.
overflow pulse, i.e., interrupt pulse INP
It is 1. Therefore, the cycle used in normal chopper operation to synchronize with the interrupt pulse (several ms to +
ms) can be set to a faster value (for example, 1ms). In this way, the delay for determining when restarting the chopper operation from a stopped state is shortened, and the switching operation can be performed quickly. After completing the process in step 302, step 303 is performed.
The power digital output circuit 1
Set SUP to "0" level via 8 to stop the pulse of the chopper.

If there is no stop instruction, steps 304-3
05, digital values N _c , N _a , N _f corresponding to the chopper period T _e , armature chopper conductivity α _a , and field chopper conductivity α _f obtained in the previous interrupt process are obtained.
are set in registers 403, 404, and 405 in FIG. After the setting, the process moves to step 306 and the armature current value IM is input into the microcomputer 1 via the analog input circuit 7. and,
If the value is very large, it is abnormal, so the switch 145 shown in FIG. 7 is opened via the power digital output circuit 18, and the shunt motor 132
At the same time, an alarm is displayed on the panel 21 via the digital output circuit 20. If there is no overcurrent, the process moves to step 308, where the value of the field current is input via the analog input circuit 7.
Load the IF into microcomputer 1. If this value is very large, it is abnormal, so the process moves to steps 310 and 311, and the switch 145
is opened, an alarm is displayed, the interrupt processing program is terminated, and the process returns to the MAIN program. Also, if there is no overcurrent, the process moves to step 312,
Based on the armature current command given in advance by the MAIN program and the detected value of armature current IM detected earlier, control calculations are performed to match the actually flowing current with the command value, and the Find the conductivity α _a of the child Chiyotsupa. Next, step 3
In step 13, the chopper period T _c is determined from the current flow rate α _a of the armature chopper. For example, in order to make the armature current pulsation constant at all operating points, T _c・α _a (1−
It is sufficient to find T _c according to α _a so that α _a ) is constant. Furthermore, in step 314, control is performed to match the actually flowing current with the command value based on the field current command given in advance by the MAIN program and the detected value of the field current IF detected earlier. Calculate the current flow rate α _f of the field chopper
seek.

Finally, in step 315, time is calculated.
This is a process in which the value of the digital value N _c that determines the chopper period T _c is added, and the following equation is calculated.

N= _k+j 〓 ^i=k N _c (i) ...(5) However, N _c (i) is a digital value that determines the chopper period obtained in the i-th interrupt process. k means that the interrupt processing that resets the time addition is the kth time.

Using N in equation (5), it is possible to determine how much time has passed since the kth reset. especially,
Even if the chopper period changes from moment to moment, equation (5) correctly calculates the result of changing the period, so time can be calculated with the accuracy of the chopper period. By using this value N, for example, a timer operation when switching between power running and regeneration can be realized without adding a hardware timer.

When a shunt motor is controlled with the configuration described above, since a microcomputer is used, the control performance does not change due to temperature and environmental changes, and a highly reliable and compact device can be realized. Furthermore, since the field chopper is synchronized with the armature chopper and the armature chopper is synchronized as an interrupt process, processing by the microcomputer is simplified. Furthermore, even if the period of the armature chopper changes, the use of a conduction rate control oscillation circuit as shown in FIG. 5 has the effect that the conductivity of the field chopper can be controlled independently. Furthermore, in the interrupt processing program shown in Figure 10, the chopper cycle at the time of stop is independently set to a smaller value than normal, so the interrupt pulse INP
1 is activated more frequently than usual, and the delay time when switching from stop to chopper operation is reduced. In addition, by using a timer based on the tip-over period T _c , the hardware configuration becomes simple without requiring a hardware timer, and the software is also simple because all you have to do is add the tip-up period. be.

As explained above, according to the present invention, the field chopper is synchronized with the armature chopper, and the generation of interrupt pulses is also synchronized, which has the effect of simplifying processing by a microcomputer.

[Brief explanation of drawings]

1 is a block diagram showing an embodiment of an electric vehicle control device according to the present invention, FIG. 2 is a block diagram showing an embodiment of the analog input control circuit of FIG. 1, and FIG. 3 is a block diagram of an embodiment of the analog input control circuit of FIG. 4 is a circuit diagram showing an embodiment of the input circuit. FIG. 4 is a circuit diagram showing an embodiment of the interrupt circuit in FIG. 1. FIG. 5 is a circuit diagram showing an embodiment of the interrupt circuit in FIG. 1. A circuit diagram showing an embodiment, FIG. 6 is an operation waveform diagram of FIG. 5, FIG. 7 is a circuit diagram showing an embodiment of the main circuit of FIG. 1, and FIG. 8 is a diagram of the speed detection circuit of FIG. 1. A circuit diagram showing one embodiment, FIG. 9 is a flowchart of an embodiment of the MAIN program showing control operations, and FIG. 10 shows the control operations of FIG. 1.
1 is a flowchart of an example of an INT program. 1... Microcomputer, 7... Analog input circuit, 10... Main circuit.

Claims (1)

[Claims] 1. A shunt motor having a field winding, a battery that supplies power to the motor, an armature chopper that controls the armature current of the motor, a field chopper that controls the field current of the motor, and the armature. A chopper conduction rate control circuit that synchronizes and drives the operating points of a chopper and a field chopper, wherein the chopper conduction rate control circuit is controlled by a first counter that counts clock pulses from an oscillator; a first register that determines the period of the conduction rate;
a first comparator that compares the output value of the first counter and the first register; a second register that determines the value of the conduction rate of the armature chopper; Counts the output pulses and generates an interrupt pulse (INPI) synchronized with the on-time of the armature chopper and field chopper each time there is an overflow.
a second comparator that compares the count value of the output pulse of the counter with the value of the second register to determine the off timing of the duty waveform of the armature chopper; a third comparator that compares the count value of the output pulses of the counter with the value of the third register and determines the off timing of the conductivity waveform of the field chopper; Means for calculating the conduction rate and cycle of the chopper for controlling the slave current and the field current is provided, and the cycle and conduction rate of the chopper are controlled in synchronization with the interrupt pulse. Control device for winding motor.