JPS5846923B2 - Denkijidoushi Yaseigiyosouchi - Google Patents

Description

[Detailed Description of the Invention] The present invention uses a shunt motor as a drive motor, and sets the armature current of this drive motor according to the amount of accelerator pedal depression.
The present invention relates to an electric vehicle control device that performs speed control using closed-loop field system control by matching this set value with the feedback value of the armature current.

Figure 1 shows a typical main circuit of a conventional electric vehicle using a field chopper type shunt motor, where E is a DC power source such as a battery, and MA and MF are the armature of the shunt motor M and the shunt field winding. lines, R1 and R2 are the armature circuit (starting resistors inserted in series, CTT1 to CTT3 are electromagnetic contactors for switching the starting resistance, CH is a field winding inserted in the MF circuit, for example, a transistor chopper, Dl and D2 is a flywheeling diode.

In the circuit shown in Fig. 1, the rotation speed of the electric motor M is set by the amount of depression of the accelerator pedal, and the rotation speed of the electric motor M is switched in three stages, that is, the electromagnetic contactors CTT1 to CTT3 are sequentially turned on depending on the motor rotation speed level. starting resistance R1,
The gear progression is accelerated by voltage control of the R2 short circuit, and the field control area is set in a predetermined pattern, and the conduction angle of the field chopper CH is reduced depending on the amount of accelerator depression, that is, the speed, and the field current is reduced to control the speed. Also, during braking, the electromagnetic contactors CTTI to CTT3 are turned off, power is regenerated by the diode D1, and the vehicle is decelerated to a stop.

At this time, regenerative braking is performed by changing the field current in stages from the rotational speed of the electric motor M by utilizing the resistance switching of the advance gear during the car travel.

In this conventional method, the field control range is set by the motor M rotational speed, so the acceleration power is suppressed, and torque fluctuations occur without changing the field control range while driving with a constant pedal stroke amount, and the field current changes during regeneration. Since the setting value is changed over several stages, the braking force is applied in stages, which has the disadvantage of deteriorating the driving feeling.

Moreover, since the field control system is open loop, the power supply voltage E
The field current range fluctuates due to fluctuations in the field current, which may cause problems such as rectification problems in the motor and destruction of the transistor CH.

In addition, as a method other than this field control, there is an armature chopper method that uses a series-wound DC motor and has a chopper in its armature circuit, but in this method, the armature current is intermittent from the chopper O, so the power discharge current is Since the waveform is in the form of a pulse wave, radio wave interference, the noise of semiconductor elements during chopper operation, the noise of the smoothing reactor commutation element installed in the armature circuit remain and are audible while driving, and commutation errors and commutation elements Since the safety device is required to operate at high speed due to the destruction of the motor, there are disadvantages such as high cost (as well as large losses during steady running such as commutation loss and element loss).

The present invention is a field control type motor in which a shunt motor is used as a drive motor.The armature current of the drive motor is set by the accelerator pedal depression amount, and the armature current feedback value is matched against this set value. An object of the present invention is to provide an electric vehicle control device intended to improve the driving feeling by controlling the speed by controlling a magnetic system and controlling the switching of starting resistance by the sum of the motor rotation speed and the amount of accelerator depression.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows the main circuit configuration of the present invention, with the same parts as in FIG. f is a field current detector such as a shunt or a Hall element.

As is clear from this circuit, the power regeneration diode D1 provided in the conventional device is omitted.

In the present invention, as described above, the armature current of the drive motor M is set by the accelerator pedal depression amount, and the control of the electromagnetic contactors CTTI to CTT3 for shorting the starting resistor is determined by the sum of the motor rotation speed and the accelerator depression amount. Let's do it.

FIG. 3 shows the speed control characteristics of the electric motor M when the vertical axis represents the motor rotation speed (rpm) and the horizontal axis represents the amount of accelerator pedal depression, that is, the motor armature current.

In this characteristic diagram, the vertical one-dot chain line L1 is the current setting value when the accelerator depression amount is maximum, and the vertical two-dot chain line L2 is the current value at the time of overload such as when traveling uphill.

Also, in the area between lines 11 and 12, the starting resistance is R1+R2
In the speed control range when , 11 is when the field is maximum strengthened, and 12 is when the field is maximum weak.

The area between lines 13 and 14 is the speed control area when the starting resistance is R2, 13 is the maximum field strength and 14 is the field maximum weaken.

The area between lines 15 and 16 is the speed control area when the starting resistance is zero, 15 is the maximum field strength and 16 is the field maximum weaken.

In the present invention, line 13 (maximum field strength when starting resistance R2) is the switching level of electromagnetic contactor CTT2, and line 15 (maximum field strength when starting resistance is zero) is the switching level of electromagnetic contactor C
Set to the switching level of TT3.

The speed range that exceeds the xty point of level 13.15 overlaps with the speed range of the next gear, so if you switch in those speed ranges, you can eliminate the fluctuation of the voltage drop of the starting resistor and accelerate the gear progression without shock. By switching at the X and Y points, the control range for inserting a starting resistor can be minimized.

In the present invention, the x and y points are determined from the sum of the accelerator depression amount and the signal amount of the motor M rotational speed, and the electromagnetic contactors are switched respectively.

Next, the control system will be explained.

FIG. 4 shows a control circuit for when the vehicle is moving.A is an accelerator depression amount detector which includes a variable resistor, a magnetic resistance element, etc. and outputs a signal corresponding to the amount of accelerator depression, and the signal is added.

given to j.

C is a comparator that outputs a field control signal according to the output of the adder S, d is an amplifier, CH and f are the field current control transistor and field current detector shown in FIG. 2, and g is the transistor. A field current maximum value limiter circuit that sets the allowable current range of CH or field winding MF, and outputs when the detected value of the field current detector f exceeds the set value, h
Is is a field current minimum value limiter circuit that sets a minimum current value in order to eliminate problems with rectification of the electric motor M, and outputs an output when the detected value of the field current detector f is below the set value, and Is is the second minimum value limiter circuit. In the armature current detector shown in the figure, each of these elements constitutes a closed-loop field current detector.

This control system compares the armature current setting value (accelerator depression amount) with the armature current from the detector Is and controls the field current based on the deviation, thereby making the armature current match the setting value. It's in control.

Next, k is a motor rotation speed detector that outputs a DC analog value according to the rotation speed of the electric motor M, and l is the accelerator depression amount and motor rotation from the operating point of the electromagnetic contactor CTT1 and addition point j according to the accelerator depression amount. The electromagnetic contactor CTT2. A level detector detects the switching operation point of the above-mentioned points x and y in Fig. 3 of CTT3, m is a micro reed relay that operates by detecting the field current shown in Fig. 2, and p is an electromagnetic contactor CTTI, CTT2. , CTT3 excitation circuit,
i' is an excessive current detector that detects when an excessive current flows when the vehicle is on a slope, etc., turns off the electromagnetic contactors CTT1, CTT2, and CTT3, and instructs the vehicle to drive again after gearing down; m' indicates the amount of accelerator depression. A row command switch that detects the accelerator pedal switch that turns on when the pedal is depressed and generates an output, n is an AND circuit, and each of these elements is an electromagnetic contactor CTTI.

Configures the control system of CTT2 and CTT3.

Next, the operation at the time of G will be explained based on the circuit shown in FIG.

When the key switch is turned on, a power supply (about 12 V DC) is applied to the control circuit, and when the accelerator pedal switch is operated by maximum depression of the accelerator, the circuit shown in the block diagram of FIG. 4 is formed.

However, in the main circuit, the magnetic contactor CTT1 is not yet closed, and no armature current flows.

On the other hand, at this time, the field current detector f output is smaller than the set value of the minimum limiter circuit, so an output in the direction of increasing the field current is generated from this limiter circuit, and this output is applied to the comparator C through the summing point. The comparator C generates an output and makes the field control transistor CH conductive.

As a result, a current set by the minimum limiter circuit flows through the field winding circuit.

Therefore, the field current detection micro reed relay m shown in FIG. 2 is activated, and an output is generated from the circuit m shown in FIG.

That is, the operating point of the micro reed relay m is set to the minimum current value set by the minimum limiter circuit.

Furthermore, the micro reed relay m is provided with a hysteresis characteristic so that it does not turn off due to slight variations in the minimum limiter value due to temperature or other conditions.

When the maximum accelerator depression reaches approximately % of the maximum depression amount, the level detector l generates a level output for closing the electromagnetic contactor CTT1 based on the signal from the accelerator depression amount detector a, and at this time, the micro reed relay Since the outputs of the m and row command switch m' are both generated, the AND circuit n
is established, and the electromagnetic contactor C in the electromagnetic contactor excitation circuit p
The excitation circuit of the TTI is activated, and the CTTl shown in Fig. 2 is closed.
A voltage is applied to the motor armature MA circuit with starting resistors R1 and R2 inserted, and the motor M is started.

At this time, armature MA has a power supply voltage EB and a sum r of the power supply internal resistance and wiring resistance.

When closed, i=E/R1+R2+r.

A current flows. The starting current due to the closing of the electromagnetic contactor CTT1 is set to be larger than the current setting value L1 when the accelerator is depressed to the maximum, as shown in Fig. 3, so the field control system detects the signal from the armature current detector By increasing the field control transistor CH, the output of the addition point increases.
The degree of conductivity increases, thereby increasing the field current, but while the value exceeds the set value of limiter circuit g, the limiter circuit g outputs an output to reduce the field current. Since it is fed back, the field current is suppressed to a set value determined by the limiter circuit g, thereby also limiting the armature current.

Thereafter, when the rotational speed of the electric motor M increases and the armature current i decreases due to an increase in the back electromotive voltage, the current setting value corresponds to the maximum accelerator pedal depression.

The field control system matches the accelerator depression amount a and the armature current i, and when the armature current i is smaller than the set value a, the comparator C outputs the off direction output of the field control transistor CH, and vice versa. produces an on-direction output of transistor CH.

Therefore, by further depressing the accelerator, the field current is reduced within the range set by limiter circuits g and h.
As a result, the speed of the electric motor M is controlled to increase gradually between speed ranges 11 and 12 in FIG.

When the rotational speed of the electric motor M reaches the X point of the thick line 13 in FIG.
A level output for closing TT2 is generated, and based on this output, the contactor CTT2 excitation circuit in the electromagnetic contactor excitation circuit p is operated, and the electromagnetic contactor CTT2 shown in FIG. 2 is closed, shorting the starting resistor R1. , the speed range of electric motor M is 13 to 1 in Fig. 3.
Transition to between 4 and 4.

However, since point X overlaps with this 13-14 speed range, the speed shift due to the short circuit of resistor R1 is carried out without shock.

Then, with the same operation as when closing the electromagnetic contactor CTTI,
The armature current is limited by resistor switching, and by depressing the accelerator, the field current is gradually decreased within the setting range of the limiter circuits g and h, thereby controlling the motor M speed to gradually increase within the speed range 13 to 14. be done.

With this control, the rotational speed of the electric motor M further increases and when it reaches the y point of line 15 in Fig. 3, the level detector l generates a level output for exciting the electromagnetic contactor CTT3. Magnetic contactor CTT3 of base magnetic contactor excitation circuit p
The excitation circuit is excited and CTT3 in Fig. 2 is closed and resistor R2
is short-circuited, and the speed range of the electric motor M shifts to shockless between 15 and 16 in FIG.

In this case as well, speed control is performed according to armature current control and field current control similar to those described above, and the automobile is accelerated forward.

In the improvement article, if you raise the setting value of the minimum limiter circuit when starting, that is, do not weaken the field, but lower it to the specified limit value as the rotation speed increases, the inconvenience of not starting due to insufficient torque at starting can be avoided. Does not occur.

Further, the set value of the maximum limit circuit g can be soft-started by lowering the set value in advance and gradually increasing it to the specified limit value with a delay from the limiter circuit.

As a result of the above motor action, when the armature current increases and reaches the value of level L2 in Fig. 3 while the vehicle is traveling at high speed, such as when the vehicle runs uphill, the overcurrent detector i' detects this. Since gear down is instructed to the level detector l, the output from the level detector l causes the electromagnetic contactor excitation circuit p to
deenergizes each electromagnetic contactor excitation circuit, and thus the electromagnetic contactors CTT1, CTT2, and CTT3 in FIG. 2 are opened and the armature current becomes zero.

In this case, once the accelerator pedal is released, the accelerator pedal switch is turned off, that is, the gear is down, and then the vehicle is driven again by pressing the accelerator pedal to prevent overcurrent in the electric motor.

In this case, although not shown in the figure, for example, an overcurrent detector i
'Due to operating conditions, etc., the structure is such that regenerative braking will not be applied even if the accelerator pedal switch is turned off.

Next, regenerative braking will be explained with reference to FIG.

In Fig. 5, the same symbols as in Fig. 4 are the same parts, so only the different parts will be explained. ■ is a setting device that generates a regenerative current setting value signal during braking, and S detects the minimum value of regenerative current and stops regeneration. armature current level detector, q
is a level detector that detects that the rotational speed of the motor is within the range where regeneration is possible; CTT1, CTT2, CTT3 are closed,
A delay circuit for waiting for the regenerative current to rise, t is an OR circuit,
U is a level detector that detects that the rotational speed of the motor is in the non-regenerative range and sets the field current to zero to prevent unnecessary current from flowing.

Next, the regeneration operation will be explained.

When the accelerator pedal is released while the vehicle is running and the accelerator pedal switch is turned off, the regeneration control circuit shown by the block in FIG. 5 is closed.

In addition, the main circuit in Figure 2 is an electromagnetic contact & TT1゜CTT2
, CTT3 closes, and the armature MA-magnetic contactor CTT3
-CTT2-CTTl-Protection fuse F-Power supply E-Armature current detector ■8-The path of armature MA becomes a regeneration circuit.

In Fig. 5, if the output to the motor rotation speed detector is equal to or higher than the regenerative rotation speed, the level detector q is activated by this output, and the AND circuit n is established under the condition that there is an output from the micro reed relay m. Therefore, the electromagnetic contactor excitation circuit p operates and the CTTI shown in FIG. 2 occurs.

CTT2 and CTT3 are closed, or the delay circuit r is operated by its auxiliary contact which operates when CTT1 is closed;
A short output of about several hundred ms is generated, and the electromagnetic contactor CTTI is activated by the operation of the OR circuit.

Maintain the closure of CTT2 and CTT3.

In other words, during this time, a rise in the regenerative current corresponding to the output of the regenerative current setting value V is waited for.

This regenerative current is detected by the armature current detector 8, and if it rises above the current value set by the level detector S, this detector S operates and the OR circuit t causes the electromagnetic contactor CT in FIG.
TI, CTT2, and CTT3 are kept closed to perform power regeneration.

That is, at this time, if the rotation speed is sufficiently high and the voltage generated by the armature MAj is sufficiently larger than the voltage of the power supply E, regeneration is possible, and the electromagnetic contactors CTT1 and CTT
2. It is possible to close the CTT 3 and perform regeneration without power loss.

This type of regeneration is possible because the armature current is monitored and fed back to the field control system to perform field strengthening control, so the armature current does not rise suddenly. .

If the armature current does not rise within the time determined by the delay circuit r, the electromagnetic contactors CTTI and CTT2 in Fig. 2
, CTT3 is closed for a time determined by the delay circuit r, and then opened.

This means that when a gear shift occurs due to a manual gear (generally, this type of electric vehicle is equipped with a manual gear using a mechanical gear in addition to an electrical control system), for example, the manual gear is shifted during regeneration. Even if regeneration stops when a gear is shifted up, regeneration is performed without the need to press the accelerator or go into gear, and even if regeneration is stopped once in the regeneration state by turning off the accelerator pedal switch during manual gear shifting. This is to ensure that if the operation continues, the vehicle returns to the running state immediately (after the above-determined time).

When the regenerative circuit is configured, the addition point is already matched with the regenerative current i from the armature current detector 8 using the regenerative current setting value .

If the regenerative current i is larger than the setting value of the regenerative current setting device ■, the comparator C is connected to the field control transistor CH.
In the opposite case, an output is generated that turns on the field current control transistor CH.

That is, the operations of the maximum and minimum limiter circuits g and h are the same as in the case of row 1, and the hysteresis of comparator C becomes the ripple value of the regenerative current, and control is performed in the opposite manner to that in row 2.

That is, as the vehicle speed decreases, the electromagnetic contactor CTT3
, CTT2, and CTTI are sequentially opened to open the starting resistors R2 and R.
1 in sequence, and the field current is controlled in the increasing direction (in this speed range) to generate a predetermined torque and perform braking.

When the motor rotation speed decreases and the regenerative current decreases even if the excitation current set by the maximum limiter circuit g is applied, and it becomes below the set value of the regenerative current detector S, the output of the OR circuit t disappears and the magnetic contactor is excited. The holding signal to circuit p disappears, the magnetic contactor excitation circuit p is deenergized, and CTTl, CTT in Fig. 2
2. CTT3 is opened, power regeneration operation is stopped, and the vehicle is subsequently brought to a stop by mechanical braking.

The output to the motor rotational speed detector is detected by a level detector U, and when the rotational speed becomes lower than the regeneration possible range, the level detector U is activated and returns to the summing point to make the field current zero.

This prevents field current loss when regeneration is not possible.

In this regenerative operation, when the regenerative current setting value V is equivalent to engine braking, it is applied as a fixed bias to perform constant current control, but when adding pedal force proportional control or brake pedal position control to equivalent to engine braking, the regenerative current setting value The regenerative current setting value (2) is varied by the output of a pedal force detector or a brake pedal position detector, etc., and the braking force is variably controlled.

FIG. 6 shows the main circuit of another embodiment, and this example shows the starting resistance R
1 and R2 are switched by thyristor 5CR1.

This is done in 5CR2.

That is, in this circuit, thyristors 5CRI and 5CR2
Switching by commutation is performed using regenerative current, and if the rotation speed has not increased enough to enable regeneration, the electromagnetic contactor CTTI
Open the circuit.

In the example shown in FIG. 7, an electromagnetic contactor CTT4 is provided in parallel with the starting resistor R2 and the armature MA, and when the electromagnetic contactor CTT4 is closed, the resistor R2 is inserted to perform dynamic braking.

In other words, when the motor rotation speed is high, each electromagnetic contactor CTT3
, CTT2.

Electric power is regenerated via CTTl, and when regeneration becomes insufficient, each electromagnetic contactor is opened and electromagnetic contactor CTT4 is closed to perform dynamic braking.

According to the present invention, the following effects can be obtained.

In the present invention, since the instantaneous value control of the armature current is performed using the field current, compared to conventional pattern control, the linear variable range is not only widened even though only the starting resistance is switched.
Since the braking force is obtained linearly rather than in stages, the driving feeling is good.

Furthermore, since the switching of the starting resistance is controlled by the sum of the amount of accelerator depression and the rotation speed, it is possible to reduce as much as possible the driving shock caused by power fluctuations when switching the resistance.

Furthermore, since a braking diode is not required, equipment such as a heat sink is also not required, making it compact, lightweight, and economical.

Furthermore, in the present invention, a small-capacity semiconductor switching element such as a transistor is used for field current control, but unlike the armature chopper method, a large current chopper that cuts off the armature current is not required. It is possible to reduce the amount of noise caused by magnetic noise, and there is no risk of electromagnetic interference.

Moreover, since the regeneration is performed using direct current, the regeneration efficiency is high, and the advantage is that the distance traveled per charge can be increased.

[Brief explanation of the drawing]

Fig. 1 is a main circuit diagram of a conventional electric vehicle, Fig. 2 is a main circuit diagram of an embodiment of the present invention, Fig. 3 is a speed characteristic curve diagram of the electric drive according to the present invention, and Fig. 4 is a diagram of the same embodiment. FIG. 5 is a block diagram of the regeneration control circuit of the same embodiment, and FIGS. 6 and 7 are main circuit diagrams of other embodiments. E... DC power supply, MA, MF... Armature and field winding of DC shunt motor, R1, R2... Starting resistance, CTT
l, CTT2, CTT3, CTT4...Magnetic contactor, CH...Transistor for field current control, ■8...
・Armature current detector, 5CR1, 5CR2...thyristor.

Claims (1)

[Claims] 1 The driving motor is a shunt-wound or compound-wound motor that has several stages of starting resistors in series with the armature circuit, short-circuiting elements that short-circuit or insert these starting resistors, and a closed-loop field current control system. In this case, the armature current for vehicle travel is set by the amount of accelerator depression, and the armature current is controlled through the field current control system, and the short-circuiting element is operated using the signal of the amount of accelerator depression and the motor rotation speed, and when braking An electric vehicle control device that sets a braking armature current by releasing the accelerator, controls the armature current through a field current control system, and opens the short circuit element using signals of the armature current and motor rotation speed.