JPH09215322A - Control circuit of multi-phase multiplexing chopper apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain parallel output current of each chopper apparatus forming a multi-phase multiplexing chopper apparatus without enlarging and complicating the apparatus and lowering the efficiency. SOLUTION: A deviation between an output current and average current of each chopper is input to a PID(Proportional Integral and Differential) adjusting device. Even if an integral time of the PID adjusting device is longer, the PID adjusting device outputs an amount of compensation corresponding to the change of time of a current deviation because a differential operation function is provided. Moreover, an absolute value of the current deviation is calculated and whether this absolute value has exceeded the reference voltage source 5 or not is judged by the comparator and NOR element. The switch provided in the output side of the PID adjusting device is turned on and off corresponding to the judging result to prevent unwanted compensating operation only with a little current deviation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-phase multiplex system in which a plurality of chopper devices are connected in parallel, and a value obtained by dividing 360 degrees by the number of chopper devices is used as a phase difference, and each chopper device is operated with this phase difference. The present invention relates to a control circuit for a chopper device.

[0002]

2. Description of the Related Art FIG. 3 is a main circuit connection diagram showing a conventional example of a multi-phase multiple chopper device. In FIG. 3, m chopper devices are connected in parallel. For example, the first chopper device of the first unit is composed of a first chopper section 11 which is an antiparallel connection of a transistor and a diode, a first reactor 21 and a first freewheel diode 31, and a second chopper of the second unit. Similarly, the device is composed of the second chopper unit 12, the second reactor 22, and the second freewheel diode 32. The m-th m-th chopper device is also the m-th chopper unit 13.
And the mth reactor 23 and the mth freewheel diode 33. These m chopper devices are connected in parallel to convert DC power from the common DC power supply 1,
The DC motor 2 as a common load is driven. Here, the current supplied by each chopper device to the DC motor 2 is given a common flow rate command value to each chopper device so that each of them contributes 1 / m of the total current, and the chopper devices mutually operate. Each chopper device is equipped with a separate phase shift conversion circuit (not shown) so that the phase difference between them is maintained at 360 degrees divided by m.

That is, the multi-phase multi-chopper device operates while the phases of the chopper devices are evenly shifted and the currents supplied to the loads are equally shared by the chopper devices.

[0004]

In the case where the control circuit of the multi-phase multiple chopper device is composed of analog circuits, if there is an error in the adjustment of each phase shift conversion circuit, this error will be given to each chopper device. There is an error in the duty ratio command value, which causes imbalance in the output current of each chopper device. Even if the error of the duty ratio command value is small at first, the output current of the chopper device with the larger value of the duty ratio command value flows back to the chopper device with the smaller duty ratio command value. The degree of current imbalance shared by each chopper device gradually increases, and eventually the rated value is exceeded. Even if there is no imbalance in the duty ratio command values, if there is a difference in the operating characteristics of the semiconductor switch elements that make up the respective chopper sections, this also causes an imbalance in the output current. As a result, a current concentrates on a specific chopper device, which overloads the chopper device, causing a failure of the main circuit element. Alternatively, even if the main circuit element is not damaged, the operation of the multi-phase multiple chopper device cannot be continued.

Therefore, in order to prevent the occurrence of such a problem, a diode for preventing backflow is connected in series to the chopper portion of each chopper device so that the current flows from the chopper device with the larger value of the conduction ratio command value. The current is prevented from flowing backward to the chopper device having the smaller rate command value. Or, by providing each chopper device with a current control circuit,
A predetermined output current can be maintained to prevent an overcurrent state. However, providing a backflow prevention diode in each chopper device causes the device to become large in size and reduces operating efficiency, and providing a separate current control circuit in each chopper device makes the device large and complicated. There is a drawback that brings.

Therefore, an object of the present invention is to increase the size of the device.
The object is to balance the output currents of the chopper devices constituting the multi-phase multiple chopper device without complicating or reducing the efficiency.

[0007]

In order to achieve the above object, the control circuit of the multi-phase multi-chopper device of the present invention is connected to a DC power supply and outputs a DC voltage different from that of the DC power supply. A plurality of devices are connected in parallel and a common flow rate command value is given to each of these chopper devices.
In a multi-phase multiple chopper device for operating each of the chopper devices, a value obtained by dividing 0 degree by the number of the chopper devices is set as an operation phase difference between the chopper devices. The total value is detected by the total current detector, and the divider calculates the average current by dividing the total current by the number of chopper devices. The current deviation between this average current and the output current of each chopper device is determined by the difference current detector, and this is input to the proportional-plus-integral-derivative controller, and the adjustment signal for making this input-current deviation zero is the relevant proportional-integral-derivative adjustment. The output time is set to be sufficiently longer than the operating cycle of the chopper device to prevent mutual interference between the conduction ratio control and the chopper current imbalance suppression operation. I'm out. However, if the integration time is long, the transient response performance when a steep current deviation occurs decreases.
According to the invention, the controller is provided with the differential operation function and outputs a large adjustment signal when the current deviation occurs, thereby improving the transient response. Furthermore, a switch is provided on the output side of the proportional-plus-integral-derivative controller, and this switch is turned on only when the absolute value of the current deviation exceeds a predetermined value, which is unnecessary when the current deviation is small. It is possible to prevent the correction operation from being performed.

In the second invention, the total value of the output currents of the chopper devices is detected by the total current detector, and the divider divides the total current by the number of chopper devices to calculate the average current. The current deviation between the average current and the output current of each chopper device is obtained by the difference current detector, and this is input to the proportional-plus-integral regulator, and the adjustment signal that makes this input-current deviation zero is output from the proportional-plus-integral regulator. The output is performed, but the integration time of the proportional-plus-integral regulator is set to be sufficiently longer than the operation cycle of the chopper device to prevent mutual interference between the conduction ratio control and the chopper current imbalance suppression operation. However, if the integration time is long, the transient response performance when a steep current deviation occurs decreases, but in the second invention, the product of the output value of the proportional-plus-integral regulator and the absolute value of the above-mentioned current deviation is calculated. By providing a multiplier and correcting this multiplication operation result,
The transient response when a steep current deviation occurs is improved. Furthermore, a switch is provided on the output side of the proportional-plus-integral controller, and this switch is turned on only when the absolute value of the current deviation exceeds a predetermined value, and unnecessary correction is made when the current deviation is small. Avoid taking action.

In a third aspect of the invention, the total value of the output currents of the chopper devices is detected by a total current detector, and the divider divides the total current by the number of chopper devices to calculate an average current. A current deviation between this average current and the output current of each chopper device is obtained by a difference current detector, and this is input to a proportional controller, and an adjustment signal for making this input current deviation zero is output from the proportional controller. However, by setting the proportional gain of this proportional controller to a desired value, the correction amount can be obtained without a time delay, and the transient response is improved. Furthermore, a switch is provided on the output side of the proportional controller, and this switch is turned on only when the absolute value of the current deviation exceeds a predetermined value, and unnecessary correction is made when the current deviation is small. Avoid taking action.

In a fourth aspect of the invention, the total value of the output currents of the chopper devices is detected by a total current detector, and the divider divides the total current by the number of chopper devices to calculate an average current. A current deviation between this average current and the output current of each chopper device is obtained by a difference current detector, and this is input to a proportional controller, and an adjustment signal for making this input current deviation zero is output from the proportional controller. However, by setting the proportional gain of this proportional controller to a desired value, the correction amount can be obtained without a time delay, and the transient response is improved. Further, a switch is provided between the input and output of the operational amplifier of the proportional controller, and the switch is turned off only when the absolute value of the current deviation exceeds a predetermined value, so that the current deviation is small. Avoiding unnecessary correction operations sometimes being performed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a circuit diagram showing a first embodiment of the present invention and corresponds to claim 1. In this first embodiment circuit as well, m chopper devices are connected in parallel to form a polyphase multiplexer, but in order to avoid complicating the drawing, only the first and mth units are shown. The remaining chopper device is not shown.

In this first embodiment circuit, the output current of the first chopper device is detected by the first current detector 131, and the output current of the mth chopper device is detected by the mth current detector 133. Further, the total current detector 3 detects all the currents flowing to the DC motor 2. The divider 4 divides the total current detected by the total current detector 3 by the operating number m to obtain the average current per unit. When the first difference current detector 41 obtains the deviation between this average current and the output current of the first chopper device, and inputs this deviation to the first proportional-plus-integral-derivative controller (abbreviated as PID controller below) 51. , An adjustment signal for making the input deviation zero is transmitted via the first switch 61 to the first adder 71.
To the correction signal. The first adder 71 gives the result obtained by adding the correction signal to the flow rate command value to the first phase shift converter 81, and this is given to the first chopper section 11 as the flow rate command value. Similarly, in the m-th chopper device, the m-th differential current detector 43 calculates the deviation between the average current and the m-th chopper device output current, and this deviation is calculated as
Since the input signal is input to the ID adjuster 53, an adjustment signal for making the input deviation zero is output via the m-th switch 63.
3 as a correction signal, and the result of adding the correction signals is sent to the m-th chopper unit 13 via the m-th phase shift converter 83.
Is given as a flow rate command value.

Here, the integration time of each PID controller is set to a time sufficiently longer than the operation cycle of each chopper section in order to avoid interference during control. In order to prevent the deterioration of the transient response performance due to this long integration time, the regulator is equipped with a differential operation function,
The correction amount corresponding to the magnitude of the temporal change in the current deviation is output. Further, the first absolute value calculator 101 and the m-th absolute value calculator 103 calculate the absolute value of the current deviation, and it is determined whether the absolute value exceeds the reference voltage source 5 by the first comparator 111 and the first comparator 111. The 1-NOR element 121 or the m-th comparator 113 and the m-NOR element 123 make a decision, and the first switch 61 or the m-th switch 63 is turned on / off according to the decision result. That is, when the current deviation does not exceed the value defined by the reference voltage source 5, each switch is turned off to prevent unnecessary correction operation with a slight current deviation.

FIG. 2 is a circuit diagram showing a second embodiment of the present invention and corresponds to claim 2. In this second embodiment circuit as well, m chopper devices are connected in parallel to form a polyphase multiplexer, but in order to avoid complicating the drawing, the control circuits are the first and mth units. It is the same as in the case of the first embodiment circuit described above, in which only the illustration is shown and the rest is omitted.

In the second embodiment circuit, instead of the first PID controller 51 and the mPID controller 53, a first PI controller 151, a first multiplier 161, and an mPI controller 1 are provided.
The third embodiment is different from the above-described first embodiment circuit in that it is provided with 53 and the m-th multiplier 163, and is otherwise the same, so the description of the same parts will be omitted. In the circuit of the second embodiment, the current deviation is input to the PI controller (proportional-integral controller), but since it does not have a differential operation function, the transient response performance is inferior to that of the PID controller. Therefore, by providing a multiplier that calculates the product of the output signal of the PI controller and the absolute value of the current deviation, and adding the multiplication calculation result as a correction signal to the flow rate command value, transient response performance is not deteriorated. I have to.

FIG. 4 is a circuit diagram showing a third embodiment of the present invention and corresponds to claim 3. This third embodiment circuit also connects m chopper devices in parallel to form a polyphase multiplexer. However, in order to avoid complicating the drawing, the control circuits are the first and mth units. It is the same as in the case of the first embodiment circuit described above, in which only the illustration is shown and the rest is omitted.

The circuit of the third embodiment includes the first P controller 251 and the mP controller 253 instead of the first PID controller 51 and the mPID controller 53. Since it is different from the circuit and is otherwise the same, the description of the same parts will be omitted.
In the circuit of the third embodiment, the current deviation is input to the P adjusters (proportional adjusters), but by optimizing the proportional gain of each P adjuster, the correction amount can be obtained without a time delay. The transient response performance is not reduced.

FIG. 5 is a partial circuit diagram showing a fourth embodiment of the present invention and corresponds to claim 4. The partial circuit of the fourth embodiment includes a first P regulator 251 and an mP regulator 253 of the third embodiment circuit, and a first P regulator 251 and an mP regulator 253. The first analog switch 261 and the m-th analog switch 263 are provided, and the first switch 61 and the m-th switch 63 of the circuit of the third embodiment are deleted, and the first NOR gate element 121 and the m-th NOR gate element 123 are included. Instead, it is different from the circuit of the third embodiment described above in that the first OR element 221 and the m-th element 223 are provided, and the other parts are the same, and therefore the description of the same parts will be omitted. To do.

That is, the first absolute value calculator 101, the m-th
The absolute value calculator 103 calculates the absolute value of the current deviation, and it is first determined whether the absolute value exceeds the reference voltage source 5.
The comparator 111 and the first logical sum element 221 or the mth comparator 113 and the mth logical sum element 223 make a decision, and the first analog switch 261 or the mth analog switch 63 is turned on according to the decision result. Turn off. That is, when the current deviation does not exceed the value determined by the reference voltage source 5, each analog switch is turned on to short-circuit the input and output of the operational amplifier of each of the first P regulator 251 and the mP regulator 253. , The output values of the first P adjuster 251 and the mP adjuster 253 become zero, which prevents useless correction operation with a slight current deviation.

In the partial circuit of the fourth embodiment, the current deviation is P
Although it is input to the regulators (proportional regulators), the proportional gain of each P regulator is optimized so that the correction amount can be obtained without a time delay and the transient response performance is not deteriorated. Although not shown in the drawings, the first PID controller 51 and the mPI
The first analog switch 261 and the m-th analog switch 26 are provided between the input and output of the operational amplifiers of the D adjuster 53 or the first PI adjuster 151 and the m-th PI adjuster 153, respectively.
3 and includes a first switch 61 and an m-th switch 63.
May be deleted, and instead of the first NOR element 121 and the m-th NOR element 123, a first OR element 221 and an m-th element 223 may be provided.

[0021]

According to the present invention, in a multi-phase multiple chopper device in which a plurality of chopper devices are connected in parallel and operated, a current deviation of each chopper device is detected and the PID controller that makes this deviation zero. Correction signal obtained from the PI controller and the multiplier that calculates the product of the output signal and the absolute value of the current deviation, or the correction signal from the P controller that makes this deviation zero. By adding the duty factor command value to each chopper device, it becomes unnecessary to install a backflow prevention diode in each chopper device, or a current control circuit provided in each chopper device becomes unnecessary. It is possible to obtain an effect that each chopper device can operate while sharing the current evenly without making the device complicated and complicated and without lowering the operating efficiency and transient response performance of the device.

[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 multiphase multiple chopper device.

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

FIG. 5 is a partial circuit diagram showing a fourth embodiment of the present invention.

[Explanation of symbols]

1 DC power supply 2 DC motor as load 3 Total current detector 4 Divider 5 Reference voltage source 11, 12, 13 1st, 2nd, 2nd m-th chopper part 21, 22, 23 1st, 2nd-mth reactor 31, 32, 33 1st, 2nd, mth freewheeling diode 41, 43 1st, mth difference current detector 51, 53 1st, mth PID controller 61, 63 1st, mth switch 71, 73 1st, mth adder 81, 83 1st, mth phase shift converter 101, 103 1st, mth absolute value calculator 111, 113 1st, mth comparator 121, 123 1st, mth negative logic Sum element 131, 133 1st, mth current detector 151, 153 1st, mth PI regulator 161, 163 1st, mth multiplier 221, 223 1st, mth NOR element 251, 253 1st , MP regulator 2 1,263 first, the m-th analog switch

Claims (4)

[Claims] 1. A plurality of chopper devices which are connected to a DC power source and output a DC voltage different from the DC power source are connected in parallel, and a common flow rate command value is given to each of these chopper devices. In a multi-phase multiple chopper device that operates each of the chopper devices, a value obtained by dividing 360 degrees by the number of the chopper devices is used as an operation phase difference between the chopper devices, and a total value of output currents of the chopper devices is detected. A total current detector, a divider that calculates the average current by dividing the total current by the number of chopper devices, and a difference current detector that separately detects the difference between the average current and the output current of each chopper device, An absolute value calculator for individually calculating the absolute value of each of the differential current detection values, and a proportional-integral-derivative adjustment for separately inputting each of the differential current detection values and individually outputting an adjustment signal for making the input signal zero. A vessel, A switch provided separately on the output side of each of the proportional-plus-integral-derivative regulators, an adder for separately adding the regulation signal and the duty ratio command value obtained through the respective switches, and each of the differential current detectors. The absolute value and a reference value set separately are compared separately, and a comparison calculator that operates the switches belonging to the chopper device corresponding to the difference current detection value based on the comparison result is provided. A control circuit for a multi-phase multiple chopper device, wherein each chopper device is individually controlled based on the calculation result of the adder. 2. A plurality of chopper devices which are connected to a DC power source and which output a DC voltage different from that of the DC power source are connected in parallel, and a common flow rate command value is given to each of these chopper devices. In a multi-phase multiple chopper device that operates each of the chopper devices, a value obtained by dividing 360 degrees by the number of the chopper devices is used as an operation phase difference between the chopper devices, and a total value of output currents of the chopper devices is detected. A total current detector, a divider that calculates the average current by dividing this total current by the number of chopper devices, and a difference current detector that separately calculates the difference between this average current and the output current of each chopper device, An absolute value calculator that separately calculates the absolute value of each of the differential current detection values, and a proportional-plus-integral controller that individually inputs the differential current detection values and separately outputs an adjustment signal that makes the input signal zero. And this Switch provided separately on the output side of each proportional-plus-integral regulator, a multiplier for separately computing the product of the regulation signal obtained through each of these switches and the absolute value of the difference current detection value, and each multiplication Corresponding to the difference current detection value by separately comparing the absolute value of each of the difference current detection values and the reference value set separately, with an adder that adds the calculation result and the conduction ratio command value separately A multi-phase multiple chopper device, comprising: a comparison operator that operates the switch belonging to the chopper device based on the comparison result, and individually controls each chopper device based on the operation result of each adder. Control circuit. 3. A plurality of chopper devices which are connected to a DC power source and which output a DC voltage different from that of the DC power source are connected in parallel, and a common flow rate command value is given to each of these chopper devices. In a multi-phase multiple chopper device that operates each of the chopper devices, a value obtained by dividing 360 degrees by the number of the chopper devices is used as an operation phase difference between the chopper devices, and a total value of output currents of the chopper devices is detected. A total current detector, a divider that calculates the average current by dividing the total current by the number of chopper devices, and a difference current detector that separately detects the difference between the average current and the output current of each chopper device, An absolute value calculator that separately calculates the absolute value of each of the differential current detection values, and a proportional controller that separately inputs the differential current detection values and separately outputs an adjustment signal that makes the input signal zero. , Each of these A switch provided separately on the output side of the proportional controller, an adder for separately adding the adjustment signal and the duty ratio command value obtained via these respective switches, and each absolute value of the difference current detection value A comparator for separately performing a comparison with a reference value set separately, and operating the switches belonging to the chopper device corresponding to the differential current detection value based on the comparison result. A control circuit for a multi-phase multiple chopper device, wherein each chopper device is controlled individually based on the result. 4. A plurality of chopper devices connected to a direct current power source and outputting direct current of a voltage different from the direct current power source are connected in parallel, and a common flow rate command value is given to each of these chopper devices. In a multi-phase multiple chopper device that operates each of the chopper devices, a value obtained by dividing 360 degrees by the number of the chopper devices is used as an operation phase difference between the chopper devices, and a total value of output currents of the chopper devices is detected. A total current detector, a divider that calculates the average current by dividing the total current by the number of chopper devices, and a difference current detector that separately detects the difference between the average current and the output current of each chopper device, An absolute value calculator that separately calculates the absolute value of each of the differential current detection values, and a proportional controller that separately inputs the differential current detection values and separately outputs an adjustment signal that makes the input signal zero. , Each of these A switch provided separately between the input and output of the operational amplifier of the proportional controller, an adder for adding the angle adjustment signal and the duty ratio command value separately, and the absolute value of each differential current detection value separately. The comparison with the reference value to be set is performed separately, and the comparator belonging to the chopper device corresponding to the difference current detection value is operated based on the comparison result. A control circuit for a multi-phase multiple chopper device, wherein each chopper device is controlled individually based on the above.