JPH08228475A - Control circuit of two-phase double chopper device - Google Patents

Abstract

PURPOSE: To quickly correct the current deviation by improving the response speed in transition state without marring the stability in control. CONSTITUTION: A proportional integration and differentiation adjuster is provided on the next stage of a differential current detector 5, and when the detection value of the differential current detector 5 exceeds a specified value, a switch 32 closes the circuit by the action of a comparator 34 and a negative OR element 36, and the output signal of a proportional integration and differentiation adjuster 31 corrects the conduction ratio command value. Or, a proportional integration adjuster and a multiplier are installed on the next stage of the differential current detector 5, and when the differential current detection value gets over the specified value, the switch 32 closes the circuit, and the multiplier operates the product of the output value of the proportional differentiation adjuster and the differential detection value absolute value, and corrects the conduction ratio command value with this operation result. Or, in place of the proportional differentiation adjuster 31, a proportional adjuster is provided, and when differential current value exceeds the specified value, the switch 32 is made to close the circuit to correct the conduction ratio command value, whereby transient response performance is improved.

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 two-phase double chopper device in which two sets of chopper devices are connected in parallel and operated with a phase difference of 180 degrees.

[0002]

2. Description of the Related Art FIG. 3 is a main circuit connection diagram showing a conventional example of a two-phase double chopper device, which is a circuit described in JP-A-5-138136. In FIG. 3, for example, a first chopper unit 11 including a transistor and a diode (not shown) that are connected in antiparallel to each other, a first reactor 12, and a first freewheel diode 13 constitute a first chopper device, Similarly, the second chopper device also includes a second chopper portion 21, which is an antiparallel connection of a transistor and a diode, a second reactor 22, and a second freewheel diode 23. These first chopper device and second chopper device Common DC power supply 1 with chopper device in parallel
The DC motor 2 as a load is connected in common and is driven. Here, a common flow rate command value is given to both chopper devices so that the currents supplied from the chopper devices to the DC motor 2 are 50% each, and their operations have a phase difference of 180 degrees from each other. Drive to keep.

As described above, the two-phase double chopper device has one
When operating with a phase difference of 80 degrees, if the conduction ratio exceeds 50%, there is a period in which both chopper devices are on, so the first chopper unit 11 and the second chopper unit 21 In order to control each switching operation, each is provided with phase shift conversion circuits 18 and 28.
However, when the control circuit of the chopper device is configured by an analog circuit, if there is an error between the adjustment of one phase shift conversion circuit and the adjustment of the other phase shift conversion circuit, this error will cause the respective conduction ratios to increase. This causes an error in the command value, resulting in imbalance in the output currents of both chopper devices. As a result, the output current of the chopper device with the larger value of the conduction ratio command value flows back to the chopper device with the smaller value of the conduction ratio command value, even if the difference in the conduction ratio command value is small at the beginning. As a result, there arises an inconvenience that the difference between the currents flowing through both chopper devices becomes a large value. Alternatively, if there is a difference in characteristics between the main circuit elements of the chopper device, for example, the transistors forming the respective chopper parts, this also causes an imbalance in the current.

Therefore, the first detected by the first current detector 15
The output current of the chopper device and the output current of the second chopper device detected by the second current detector 25 are input to the difference current detector 5 to detect the difference between the two currents, and the difference current detection value is proportional-integrally adjusted. Input to the container 6. Since the proportional-plus-integral controller 6 outputs a control signal for adjusting its input to zero, the first adder 17 adds the conduction ratio command value with the polarity corrected by the output signal of the proportional-plus-integral controller 6. , The result of the addition is given to the first phase shift conversion circuit 18, whereby the first phase shift conversion circuit 1
An operation signal having an appropriate flow rate is given from 8 to the first chopper section 11. The output signal of the proportional-plus-integral controller 6 is fed to the second adder 2
7 is applied with a polarity opposite to that of the first adder 17 described above, so the reverse polarity control signal and the conduction ratio command signal are added,
The addition result is given to the second chopper unit 21 via the second phase shift conversion circuit 28.

[0005]

As shown in the conventional circuit of FIG. 3, the circuit for correcting the unbalanced current of the two-phase double chopper device is composed of the current detectors 15, 25 of the respective chopper devices.
Difference current detector 5, proportional-plus-integral controller 6, adders 17, 18
Etc., and these emphasize the average correction. Therefore, the integration time of the proportional-plus-integral adjuster 6 is extremely long (several tens to several hundreds of times) as compared with the operation cycle of the choppers 11 and 21.

Therefore, even if there is no hindrance to the steady operation of the chopper device, in a transient state in which the load is rapidly increased / decreased, the delay of the response of the control circuit causes a problem that the correction cannot be made in time. . That is, when the current of each chopper device fluctuates rapidly and a sudden current deviation occurs,
The operation of correcting the unbalanced current cannot follow this, and an excessive current may flow only to one of the chopper devices, which may damage the device. However, if the integration time of the proportional-plus-integral regulator 6 is shortened to near the operating cycle of the chopper section, the chopper devices interfere with each other to control the conduction ratio,
This causes a problem that stable control cannot be performed.

Therefore, the present invention is to enable quick correction of current deviation by improving the response speed in a transient state without impairing control stability.

[0008]

In order to achieve the above-mentioned object, the control circuit of the two-phase double chopper device of the present invention is connected to a DC power source and outputs a DC voltage having a voltage different from that of the DC power source. A two-phase double chopper device in which the first chopper device and the second chopper device are connected in parallel, and the operating phases are mutually shifted by 180 degrees with common flow rate command values given to both chopper devices. At, the difference current detector detects the difference between the output currents of the both chopper devices, and supplies this detected value to the proportional-plus-integral-derivative controller. This proportional-plus-integral-derivative regulator has a built-in differential operation circuit so as to output a large control signal so as to make the detected value zero at the initial time when the detected difference current value suddenly changes. Further, the absolute value of the difference current detected by the difference current detector is calculated, and this difference current absolute value is compared with a reference value that is set separately, and the difference current absolute value is higher than the reference value. When it is large, the switch provided on the output side of the proportional-plus-integral-plus-derivative regulator is closed, and the control signal output from this proportional-plus-integral-plus-derivative regulator is added to one of the adders with a positive polarity to the conduction ratio command value. Then, the other adder has a negative polarity and is added to the conduction ratio command value. That is, the output of the proportional-plus-integral-derivative regulator is added to one of the conduction ratio command values of the chopper device with the polarity that corrects this conduction ratio command value, and the other of the conduction ratio command values of the other chopper device is the above-mentioned. Since the output of the proportional-plus-integral-plus-derivative regulator is added in the opposite polarity to the above, the larger the current of the chopper device suddenly changes and the greater the temporal change of the difference current detection value, the greater the proportional-plus-plus-integral-derivative adjustment. Since the device outputs a control signal having a magnitude corresponding to the temporal change and corrects the duty ratio command values of both chopper devices, the transient response performance is improved.

Alternatively, the difference current detector detects the difference between the output currents of the both chopper devices and supplies the detected value to the proportional-plus-integral regulator. A multiplier is provided on the output side of the proportional-plus-integral regulator to calculate the product of the control signal output from the proportional-plus-integral regulator and the absolute value of the difference current detection value. As a result, even if the proportional-plus-integral controller has a control time delay, the larger the difference current detection value, the larger the calculation result of the multiplier.
Further, the absolute value of the difference current detected by the difference current detector is calculated, and this difference current absolute value is compared with a reference value that is set separately, and the difference current absolute value is higher than the reference value. When it is large, the switch provided on the output side of the proportional-plus-integral regulator is closed, and the calculation result of the multiplier is added to one of the adders by the positive polarity to the conduction ratio command value, and the other adder. Has a negative polarity and is added to the flow rate command value. That is, the calculation result of the multiplier is added to one of the conduction ratio command values of the chopper device with the polarity for correcting the conduction ratio command value, and the multiplication ratio command value of the other chopper device is also multiplied by the multiplication result. Since the calculation result of the multiplier is added with the opposite polarity to that described above, the larger the difference current detection value due to the sudden change in the current of the chopper device, the larger the calculation result output from the multiplier. Since the duty ratio command values of both chopper devices are corrected, the transient response performance is improved.

Alternatively, the difference current detector detects the difference between the output currents of the both chopper devices and supplies the detected value to the proportional controller. Unlike the proportional-plus-integral adjuster, the proportional adjuster does not have a control time delay and can quickly output a large control signal proportional to the detected difference current value. In addition, the proportional-integral-derivative controller requires adjustment for each of the proportional, integral, and derivative elements, and adjustment of these three elements requires skill and effort, whereas
Adjustment of the proportional controller is easy, and a large control signal can be output quickly in response to fluctuations in the differential current detection value. Further, the absolute value of the difference current detected by the difference current detector is calculated, and this difference current absolute value is compared with a reference value that is set separately, and the difference current absolute value is higher than the reference value. When it is large, close the switch provided on the output side of the proportional controller,
The control signal output by the proportional controller is added to one of the adders with a positive polarity to the conduction ratio command value and to the other adder with a negative polarity to the conduction ratio command value. That is, the output of the proportional controller is added to one of the flow rate command values of the chopper device with the polarity that corrects this flow rate command value, and the proportional control is added to the flow rate command value of the other chopper device. If the current of the chopper device suddenly changes and the difference current detection value changes, the proportional controller is proportional to the magnitude of its input value because the output of the device is added with the opposite polarity. Since a large value of the control signal is quickly output to correct the duty ratio command values of both chopper devices, the transient response performance is improved.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A first chopper device and a second chopper device are connected in parallel, and the operation phases are mutually shifted by 180 degrees with the common flow rate command values given to both chopper devices being operated by 2 degrees. In the phase double chopper device, a control signal for inputting the detected difference current of both chopper devices to the controller and taking the difference current detection value to zero is taken out from the controller, and the current output rate is obtained by the controller output value. Although the command value is corrected, in the present invention, a large correction amount is obtained when the difference current is detected by using a proportional-integral-derivative controller so that a change in the difference current detection value can be quickly responded to. Be given to the command value. Alternatively, the proportional-integral regulator and the multiplier provided on the output side of the proportional-integral regulator calculate the product of the output value of the proportional-plus-integral regulator and the difference current detection value, and use this as the correction amount to detect the difference current. A large correction amount proportional to the value is obtained to cover the control time delay caused by the integral calculation element. Or by using a proportional controller,
Make sure that the correction amount is obtained without a time delay. It should be noted that the circuit is configured so that the output signal of each of these regulators is given only when the absolute value of the differential current detection value exceeds a preset reference value.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a circuit diagram showing a first embodiment of the present invention, which corresponds to claim 1. The direct current power source 1 and the direct current shown in the first embodiment circuit of FIG. Electric motor 2, differential current detector 5, first chopper section 11, first reactor 12, first freewheel diode 13, first current detector 1
5, first adder 17, first phase shift conversion circuit 18, second chopper unit 21, second reactor 22, second freewheel diode 23, second current detector 25, second adder 2
7, and the names, uses, and functions of the second phase shift conversion circuit 28 are
Since this is the same as the case of the conventional circuit described above in FIG. 3, description thereof will be omitted.

In the circuit of the first embodiment of FIG. 1, since the proportional-plus-integral-derivative regulator 31 is installed at the next stage of the differential current detector 5, the flow current of the chopper device fluctuates transiently to cause the differential current. When the detected value changes, the proportional-plus-integral-derivative regulator 31 outputs a large signal at the beginning of the change in the detected difference current value due to the function of the differentiating circuit. If the switch 32 is closed, the output signal of the proportional-plus-integral-derivative adjuster 31 is given to the first adder 17 and the second adder 27 via the switch 32 with the polarity for correcting the flow rate command value. .

The absolute value calculator 33 calculates the absolute value of the differential current detection value, and the comparator 34 determines whether this value exceeds the reference voltage V _S set by the reference voltage source 35. In response to this judgment result, the NOR element 36
Sends an opening / closing operation signal to the switch 32 described above. That is,
If the absolute value of the detected difference current is larger than the reference voltage V _S , the switch 32 is closed and the output signal of the proportional-plus-integral-derivative controller 31 corrects the conduction ratio command value. If the voltage is lower than the reference voltage V _{S, the} switch 32 opens, so that the ground resistance 3 is applied to the first adder 17 and the second adder 27.
Zero is provided via 7. That is, no correction amount is given to the flow rate command value.

FIG. 2 is a circuit diagram showing a second embodiment of the present invention, which corresponds to claim 2. The difference between this second embodiment circuit and the above-mentioned first embodiment circuit. Instead of the proportional-plus-integral-derivative regulator 31, the proportional-plus-integral regulator 6 and the multiplier 4
1 is used, and the names, applications, and functions of the remaining parts except this are the same as those of the circuit of the first embodiment already described in FIG.

In the circuit of the second embodiment of FIG. 2, since the detected difference current value is input to the proportional-plus-integral adjuster 6, even if the detected difference current value suddenly changes transiently, the change in the output does not immediately increase. . However, since the multiplier 41 provided in the next stage of the proportional-plus-integral regulator 6 calculates the product of the output signal of the proportional-plus-plus-integral regulator 6 and the absolute value of the difference current output by the absolute value calculator 33, the difference current If the detected value suddenly changes, the calculation result of the multiplier 41 becomes a large value. The calculation result of the multiplier 41 is given to the first adder 17 and the second adder 27. That is,
The flow rate command value is corrected by the calculation result of the large value output from the multiplier 41.

FIG. 4 is a circuit diagram showing a third embodiment of the present invention, which corresponds to claim 3, but the difference between this third embodiment circuit and the above-mentioned first embodiment circuit. Means that the proportional adjuster 38 is used instead of the proportional-integral-derivative adjuster 31, and the names, applications, and functions of the remaining parts excluding this are the same as those of the circuit of the first embodiment described in FIG. Is. In the third embodiment circuit of FIG. 4, the differential current detection value is set to the proportional controller 3.
Since the value is input to 8, the output of the proportional controller 38 immediately outputs a value corresponding to the input value without causing a time delay when the differential current detection value suddenly changes.
If the proportional constant of is properly selected, a large output signal
It is given to the adder 17 and the second adder 27. That is, the flow rate command value is quickly corrected by the large value output by the proportional controller 38.

[0018]

In the two-phase double chopper device in which two sets of chopper devices are operated in parallel, conventionally, the difference current detection value is made zero by inputting the difference between the output currents of both chopper devices to the proportional-plus-integral controller. The control signal to be obtained is calculated, and the conduction ratio command value common to both chopper devices is corrected by this control signal, but since the integration time of the proportional-plus-integral regulator is much longer than the operating cycle of the chopper device, I could not follow the rapid change in the difference current. Therefore, the current deviation is increased, and there is a risk that one of the chopper devices is destroyed by an overcurrent.

In the first aspect of the present invention, a proportional-plus-integral-derivative adjuster is adopted in place of the proportional-plus-integral adjuster so that a large correction signal command signal is obtained when a difference current is detected. Further, although the proportional-integral regulator is used as it is in the second invention, a multiplier for computing the product of the output of the proportional-integral regulator and the difference current detection value is installed, and the output of this multiplier is used to set the conduction ratio command. The value is corrected. In the third aspect of the invention, a proportional controller is used instead of the proportional-integral controller so that the correction signal command signal can be obtained without causing a time delay when detecting the difference current. With such a configuration, when the difference current between both chopper devices fluctuates abruptly due to a sudden change in current, the proportional-integral-derivative-derivative controller, the multiplier, or the proportional controller quickly outputs a large correction signal in either invention. Then, the flow rate command value is corrected. Therefore, in the first invention that uses the proportional-plus-integral-derivative regulator and the second invention that uses the proportional-plus-integral regulator and the multiplier in combination, the difference current can be corrected quickly without shortening the integration time to destroy the device. Since it is prevented in advance, the effect of avoiding instability of control due to shortening of the integration time can be obtained. Further, in the third invention using the proportional controller, since it is not necessary to adjust the integral element and the derivative element, it is possible to prevent the destruction of the device by correcting the difference current quickly while significantly reducing the labor of the adjustment. Is obtained.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a second embodiment of the present invention.

FIG. 3 is a main circuit connection diagram showing a conventional example of a two-phase double chopper device.

FIG. 4 is a circuit diagram showing a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 DC power supply 2 DC motor 5 Differential current detector 6 Proportional integration regulator 11 1st chopper part 12 1st reactor 13 1st freewheel diode 15 1st current detector 17 1st adder 18 1st phase shift conversion circuit 21 2nd chopper part 22 2nd reactor 23 2nd freewheel diode 25 2nd current detector 27 2nd adder 28 2nd phase shift conversion circuit 31 proportional-plus-integral-derivative regulator 32 switch 33 absolute value calculator 34 comparator 35 reference voltage Source 36 NOR element 37 Ground resistance 38 Proportional adjuster 41 Multiplier

Claims (3)

[Claims] A first chopper device and a second chopper device, which are connected to a direct current power source and output a direct current having a voltage different from that of the direct current power source, are connected in parallel, and a conduction ratio command is given to both chopper devices. The values are common and the operating phases are 180
In a two-phase double chopper device that is operating with a staggered operation, a differential current detector that detects the difference between the output currents of the two chopper devices, and a proportional-plus-integral-derivative regulator that outputs a control signal that makes the difference current zero. A first adder for adding the output of the proportional-plus-integral-derivative controller to the conduction ratio command value of the one chopper device with a polarity for correcting, and the proportional ratio to the conduction ratio command value of the other chopper device. A second adder for adding the output of the integral / differential controller with a polarity opposite to the above, an absolute value calculator for calculating the absolute value of the difference current detected by the difference current detector, and this difference current absolute value And a reference value, and a switch that operates with the output signal of the comparison operator, and when the absolute value of the difference current is larger than the reference value, the switch is closed, and The output of the proportional-plus-integral-derivative regulator is output via a switch. The control circuit of the two-phase double chopper device, wherein the force is added to the conduction ratio command value with a positive polarity in the one adder and is added to the conduction ratio command value with a negative polarity in the other adder. . 2. A first chopper device and a second chopper device, which are connected to a direct current power source and output a direct current having a voltage different from that of the direct current power source, are connected in parallel, and a conduction ratio command is given to both chopper devices. The values are common and the operating phases are 180
Along with the offset, a difference current detector that detects the difference between the output currents of the both chopper devices, a proportional-plus-integral regulator that outputs a control signal that makes this difference current zero, and a conduction ratio command value for one chopper device. Is a first adder that adds the output of the proportional-plus-integral controller with a polarity that corrects the output of the proportional-plus-integral regulator with the opposite polarity to the conduction ratio command value of the other chopper device. Two-phase two with a second adder for adding
In the control circuit of the heavy chopper device, an absolute value calculator for calculating the absolute value of the difference current detected by the difference current detector, a comparison calculator for comparing the difference current absolute value with a reference value, and this comparison calculation A switch that operates with the output signal of the switch, and a multiplier that calculates the product of the output signal of this switch and the absolute value of the difference current, and the switch when the absolute value of the difference current is greater than the reference value Is closed, and the multiplication result of the output of the proportional-plus-integral regulator and the absolute value of the difference current is added through this switch to the conduction ratio command value with positive polarity in the one adder, and the addition of the other is added. 2 phase 2 which is characterized by adding negative current to the flow rate command value
Control circuit for heavy chopper device. 3. A first chopper device and a second chopper device, which are connected to a direct current power source and output a direct current of a voltage different from that of the direct current power source, are connected in parallel, and a conduction ratio command is given to both chopper devices. The values are common and the operating phases are 180
In a two-phase double chopper device that is operating with a staggered operation, a difference current detector that detects a difference between the output currents of the both chopper devices, and a proportional controller that outputs a control signal that makes the difference current zero. A first adder for adding the output of the proportional controller with a polarity for correcting the duty ratio command value of one chopper device, and the output of the proportional regulator for the duty ratio command value of the other chopper device. With a polarity opposite to the above, an absolute value calculator for calculating the absolute value of the difference current detected by the difference current detector, and a comparison of this difference current absolute value with a reference value. And a switch operated by an output signal of the comparison calculator, and when the absolute value of the difference current is larger than the reference value, the switch is closed and the proportional circuit is connected through the switch. The output of the regulator is positive in the one adder It is characterized in that the current is added to the flow rate command value, and the other adder is negatively added to the flow rate command value.
Control circuit for the phase double chopper device.