JPH08168252A - Method for controlling ac-dc converter - Google Patents

Abstract

PURPOSE: To obtain an AC-DC converter control method by which such a system that the outputs of controllers can become almost the same without being affected by the transmission time lags between signals transmitted between the controllers at the time of controlling an AC-DC converter with the multiplexed controllers. CONSTITUTION: The output values of its own device and another device are corrected so that they can become equal to each other by feeding back the difference between the output values of control circuits, such as the constant- current control circuits 9A and 9B, constant-voltage control circuits 10A and 10B, etc., of its own device and another device to the input sections of the devices through correction control circuits having large time constants, such as correction control circuits 22A and 22B for constant-current control circuits, correction control circuits 25A and 25B for constant-voltage control circuits, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of controlling an AC / DC converter, which controls the AC / DC converter by a multiplexed control device.

[0002]

2. Description of the Related Art FIG. 5 shows, for example, JP-A-5-176542.
FIG. 6 is a block diagram showing a configuration of a control device to which a conventional method for controlling an AC-DC converter shown in Japanese Patent Publication is applied. In the figure, 1 is a conversion transformer, 2 is a forward converter that converts AC power into DC power, and a thyristor converter that operates as an inverse converter that converts DC power into AC power, and 3 is a thyristor converter. 2 is a DC reactor for smoothing the output. Reference numerals 4A and 4B are multiplexed control devices of the AC / DC converter, and reference numeral 5 is a gate pulse generator that generates a gate pulse to the thyristor converter 2 based on signals from the control devices 4A and 4B. Reference numeral 6 denotes a DC current transformer (hereinafter referred to as DCCT) that detects a DC current Idc of the thyristor converter 2 and inputs it to each of the control devices 4A and 4B. Reference numeral 7 denotes a DC transformer (hereinafter referred to as DCPT) that detects the DC voltage Vdc of the thyristor converter 2 and inputs it to each of the control devices 4A and 4B. Reference numeral 8 denotes an AC transformer (hereinafter referred to as ACPT) that detects the voltage of the AC system and inputs the AC voltage Vac to each of the control devices 4A and 4B.
Is.

Further, inside the control devices 4A and 4B, 9A and 9B are constant current control circuits as control circuits for controlling DC current to a predetermined value, and 10A and 10B control DC voltage to a constant value. It is a constant voltage control circuit as a control circuit that operates. Reference numerals 11A and 11B denote constant margin angle control circuits for ensuring a minimum margin angle to prevent commutation failure. 12A and 12B are direct current I from DCCT6
Current command value to be added (subtracted) to dc, 13A, 1
Reference numeral 3B is an adder that adds the current command values 12A and 12B to the DC current Idc in reverse polarity and supplies the current command values 12A and 12B to the constant current control circuits 9A and 9B. 14A and 14B are voltage command values to be added (subtracted) to the DC voltage Vdc from the DCPT 7, and 15
A and 15B are the DC voltage Vdc and the voltage command values 14A and 1
4B are added in reverse polarity, and constant voltage control circuits 10A and 10B are added.
It is an adder that supplies to.

16A and 16B are constant current control circuits 9A and 9B.
B is a selection circuit that selects an output to be used for control from the outputs of the constant voltage control circuits 10A and 10B and the constant margin angle control circuits 11A and 11B. 17A and 17B are transmission circuits between the redundant control devices 4A and 4B.
A and 18B are dual system selections for selecting an appropriate control output from the output of the selection circuit 16B (16A) of the partner device and the output of the selection circuit 16A (16B) of the own device exchanged by the transmission circuits 17A and 17B. Circuit. 19A and 19B are phase control circuits that determine the timing of the gate pulse based on the control output selected by the dual system selection circuits 18A and 18B. 20A and 20B are phase control circuits 19A based on the AC voltage Vac from the ACPT 8. , 19B for producing a synchronization detection circuit.

Next, the operation will be described. Current command value 1
2A and 12B and voltage command values 14A and 14B are given to the two control devices 4A and 4B, respectively. The same DC current Idc from DCCT6, DC voltage Vdc from DCPT7, AC voltage from ACPT8 are given. Vac is also 2
The same input is given to the two controllers 4A and 4B. The DC current Idc and the current command values 12A and 12B are input to the adders 13A and 13B with opposite polarities. When the DC current Idc deviates from the current command values 12A and 12B, the adders 13A and 13B Output is constant current control circuit 9
The control angle of the thyristor converter 2 is changed in order to make the current constant by being input to A and 9B.

Similarly, in the adders 15A and 15B, when the direct current voltage Vdc and the voltage command values 14A and 14B input with opposite polarities are deviated from each other, the adders 15A and 1B are added.
The output of 5B is input to the constant voltage control circuits 10A and 10B, and the control angle of the thyristor converter 2 is changed so that the voltage becomes constant. In addition, the constant margin angle control circuit 11
A and 11B also output a signal that determines the control angle of the thyristor converter 2 based on the information on the DC current Idc and the AC voltage Vac. These constant current control circuits 9A, 9B, constant voltage control circuits 10A, 10B, and constant margin angle control circuits 11A, 1
From the signals output from 1B, the selection circuits 16A and 16B
Depending on, for example, by selecting the minimum value, the control device 4
Determine the control output of A and 4B.

However, as shown in the figure, a plurality of (two) control devices 4A and 4B are multiplexed (duplexed).
If so, the outputs of the selection circuits 16A and 16B do not always match due to changes in circuit constants and constituent elements. Therefore, the selection circuits 16A of the two control devices 4A and 4B,
It is necessary to exchange the output of 16B via the transmission circuits 17A and 17B and collate with each other. As a result of the collation, if the two do not match, the dual control circuit 18A selects the control angle with the larger control angle on the forward converter side and the smaller control angle on the inverse converter side to take the safety side. , 18B. The control output selected by the dual system selection circuits 18A, 18B is input to the phase control circuits 19A, 19B, and the phase control circuits 19A, 19B determine the timing of the gate pulse based on the input. This timing signal is sent to the gate pulse generator 5, a gate signal based on the timing is output from the gate pulse generator 5, and the thyristor converter 2 is controlled.

[0008]

Since the conventional method of controlling the AC-DC converter is configured as described above, the two constant current control circuits 9A and 9B and the two constant voltage control circuits 10A and
Since no correction is applied to 10B, once a difference occurs in the output between the two control devices 4A and 4B, the output will not be reduced forever and the control will not be improved. Since the control output is selected while comparing the outputs, there is a problem that the system becomes unstable because a delay element is included for the data transfer time between both systems.

The present invention has been made to solve the above problems, and an object thereof is to obtain a control method for an AC / DC converter in which the outputs of the control circuits in each series are matched.

Another object of the present invention is to provide a control method for an AC / DC converter in which one-sided control device outputs an abnormal value so as not to affect the other side as much as possible. Further, it is another object of the present invention to obtain a control method of an AC / DC converter, which can judge only by the information in its own device when comparing outputs.

[0011]

According to a first aspect of the present invention, there is provided a control method for an AC / DC converter according to a difference between output values of control circuits of its own device and other devices in each of a plurality of series of control devices. The amount is added to the input value of the control circuit of the device itself.

According to a second aspect of the present invention, there is provided a control method for an AC / DC converter, wherein in each of the control devices of a plurality of systems, the control of the own device is performed according to the difference between the output values of the control circuits of the own device and other devices. The circuit parameters are modified.

According to a third aspect of the present invention, there is provided a method for controlling an AC / DC converter, wherein in each control device of a plurality of systems, the normal / normal condition of each control device is determined based on the output values of the control circuits of the own device and other devices. An abnormality is discriminated, and only when the abnormality is normal, an amount corresponding to the difference between the output values is added to the input value of the control circuit of the own device.

According to a fourth aspect of the present invention, in a control method for an AC / DC converter, in each of the control devices of a plurality of systems, the difference between the previous output value of this device and the present output value is within a specified value. In that case, the output value is immediately transmitted, and when the output value is equal to or larger than the specified value, the output value is transmitted according to the result of comparison with the output value of another device.

[0015]

According to the control method of the AC / DC converter in the invention described in claim 1, an amount corresponding to the difference between the output value of the control circuit of the own device and the output value of the control circuit of the other device is input to the control circuit of the own device. By adding it to the value, the output values are corrected so that they are the same, eliminating the need to exchange the control output of each system each time and collating, and it is possible to perform stable control without the influence of time delay. Realize a converter control method.

According to a second aspect of the present invention, there is provided a method for controlling an AC / DC converter, wherein a parameter of a control circuit of its own device is set according to a difference between an output value of its own control circuit and an output value of a control circuit of another device. By correcting the parameters of the control circuit and structure of each system to match them and eliminate the need to check the control output of each system every time, stable control without the influence of time delay is possible. To realize a simple AC / DC converter control method.

Further, in the control method of the AC / DC converter according to the third aspect of the invention, when the normality is confirmed by the discrimination based on the output value of the control circuit of the own device and the output value of the control circuit of the other device. Only by adding an amount corresponding to the difference between the output values to the input value of the control circuit of the own device, the output of each system is output when one system becomes abnormal and outputs a ridiculous output value. The normality of the control system is maintained by preventing the correction of the normal system in an attempt to match the values.

The control method of the AC / DC converter according to the invention of claim 4 compares the previous output value and the present output value of the device, and only when the difference is equal to or more than the specified value, the other When the control output is sent according to the result of comparison with the output value of the device, the judgment is always made using the information of the device itself to eliminate the influence of the time delay, and the output value greatly deviates from the previous value. Also, the reliability is secured by checking the output values of other devices.

[0019]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a control device to which the AC / DC converter control method according to the first embodiment is applied. In the figure, 1 is a conversion transformer, 2 is a thyristor converter,
3 is a DC reactor, 4A and 4B are control devices, 5 is a gate pulse generator, 6 is DCCT, 7 is DCPT, and 8 is A.
CPT, 9A and 9B are constant current control circuits as control circuits, 10A and 10B are constant voltage control circuits as control circuits, 11A and 11B are constant margin angle control circuits, and 12A and 12B.
B is a current command value, 13A and 13B are adders, and 14A and 1
4B is a voltage command value, 15A and 15B are adders, 16A,
16B is a selection circuit, 19A and 19B are phase control circuits, 2
Reference numerals 0A and 20B denote synchronization detection circuits, which are the same as or equivalent to those of the conventional one denoted by the same reference numeral in FIG.

Further, 21A and 21B are adders for adding the outputs of the constant current control circuits 9A and 9B of the partner device and the own device in opposite polarities, and 22A and 22B are constants based on the outputs of the adders 21A and 21B. A correction control circuit for a constant current control circuit that generates a correction signal for correcting the inputs of the current control circuits 9A and 9B, and 23A and 23B add the correction signal to the outputs of the adders 13A and 13B with opposite polarities. It is an adder. 24A and 24B are adders for adding the outputs of the constant voltage control circuits 10A and 10B of the partner device and the own device in opposite polarities, 2
Reference numerals 5A and 25B are correction control circuits for constant voltage control circuits that generate correction signals for correcting the inputs of the constant voltage control circuits 10A and 10B based on the outputs of the adders 24A and 24B, and 26A and 26B are The correction signal is added to the adder 15
It is an adder that adds the outputs of A and 15B with opposite polarities. Two
Reference numerals 7, 28, 29 and 30 denote transmission circuits which are mutually exchanged between the control devices 4A and 4B and which transmit the outputs of the constant current control circuits 9A and 9B and the constant voltage control circuits 10A and 10B.

The control unit 4 in the first embodiment
A and 4B are addition circuits 21A, 21B, 23A,
23B, 24A, 24B, 26A, 26B, constant current control circuit correction control circuits 22A, 22B, constant voltage control circuit correction control circuits 25A, 25B, and dual system selection circuits 18A, 18B are omitted. 5 is different from the conventional one shown in FIG.

Next, the operation will be described. This Example 1
In the same manner as in the conventional case, the current command values 12A, 1
2B and the voltage command values 14A and 14B are controlled by the two control devices 4
The same is given to A and 4B, and DCCT
DC current Idc from 6 and DC voltage Vd from DCPT7
c, AC voltage Vac from ACPT8 is also two control devices 4
The same input is given to A and 4B. The direct current Idc is added to the adders 13A, 23A or 13B, 2
The DC voltage Vdc is applied to the constant current control circuits 9A and 9B via 3B and to the constant voltage control circuits 10A and 10B via adders 15A and 26A or 15B and 26B.
The outputs of the constant current control circuits 9A, 9B and the outputs of the constant voltage control circuits 10A, 10B are exchanged between the two control devices 4A, 4B via the transmission circuits 27, 28, 29, 30, respectively. The outputs of the constant current control circuits 9A and 9B are added by the adders 21A and 21B, and the constant voltage control circuits 10A and 10B are output.
The outputs of B are added in opposite polarities by adders 24A and 24B.

The outputs of the adders 21A and 21B are constant current control circuit correction control circuits 22A and 22A having a large time constant.
22B, and correction signals from the constant current control circuit correction control circuits 22A and 22B are input to the adders 23A and 23B. Similarly, the outputs of the adders 24A and 24B are input to the constant voltage control circuit correction control circuits 25A and 25B having a large time constant, and the correction signals are added from the constant voltage control circuit correction control circuits 25A and 25B. Vessel 26A,
26B is input. In the adders 23A and 23B, the outputs of the constant current control circuit correction control circuits 22A and 22B are
The adders 13A and 13B have the direct current Idc and the current command value 12
A and 12B are added with opposite polarities and added to the output signal with opposite polarities, which are input to the constant current control circuits 9A and 9B. Similarly, in the adders 23A and 23B, the outputs of the constant voltage control circuit correction control circuits 25A and 25B are added to the adder 15
A and 15B are DC voltage Vdc and voltage command values 14A and 14B
And are added in opposite polarities and added to the output signal in opposite polarities,
It is input to the constant voltage control circuits 10A and 10B. In this way, the correction is performed so that the output difference between the two control devices 4A and 4B becomes small.

The outputs of the constant current control circuits 9A and 9B and the constant voltage control circuits 10A and 10B which have been subjected to such correction,
Since the signals selected by the selection circuits 16A and 16B from the outputs of the constant margin angle control circuits 11A and 11B are already substantially in agreement between the two control devices 4A and 4B, the dual system selection circuit. It is input to the phase control circuits 19A and 19B without performing verification by the above. The phase control circuits 19A and 19B determine the timing of the gate pulse based on it, and the gate pulse generator 5 generates a gate signal based on the timing signal sent from the phase control circuits 19A and 19B to generate a thyristor converter. Control 2

As described above, in the two control devices 4A and 4B, the difference between the output values of the constant current control circuits 9A and 9B and the difference between the output values of the constant voltage control circuits 10A and 10B are determined with a large time constant. Correction control circuits 22A, 22 for current control circuit
B or correction control circuit 25A, 25 for constant voltage control circuit
Since it is fed back to each input section through B, it is corrected so that the output values of both are the same, and it is not necessary to exchange the outputs of both systems each time and collate, so there is no time delay effect. A stable control system can be realized.

Although the constant current control circuit correction control circuits 22A and 22B and the constant voltage control circuit correction control circuits 25A and 25B are described as first-order delay circuits in FIG. 1, control circuits other than the first-order delay are used. However, the same effect as described above can be obtained.

Example 2. Next, another embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a block diagram showing the configuration of a control device to which the control method for an AC / DC converter according to the second embodiment is applied. Corresponding parts are designated by the same reference numerals as those in FIG. 1 and their description is omitted. In the figure, 31A and 31B are parameters and initial values of the constant current control circuits 9A and 9B based on the difference between the output values of the constant current control circuits 9A and 9B exchanged with each other via the transmission circuits 27 and 28. 32A and 32B are parameter correction circuits for correcting
This is a parameter correction circuit that corrects the parameters and initial values of the constant voltage control circuits 10A and 10B based on the difference between the output values of the constant voltage control circuits 10A and 10B that are exchanged with each other via 9 and 30. The control devices 4A and 4B according to the second embodiment use the parameter correction circuit 3
1A, 31B and 32A, 32B, adder circuit 2
1A, 21B, 23A, 23B, 24A, 24B, 26
Correction control circuit 22 for A, 26B and constant current control circuit
A, 22B, correction control circuit for constant voltage control circuit 25A, 2
5B is omitted, which is different from that of the first embodiment denoted by the same reference numeral in FIG.

Next, the operation will be described. As in the case of the first embodiment, the two controllers 4A and 4B output the constant current control circuits 9A and 9B and the constant voltage control circuit 10 respectively.
The outputs of A and 10B are transmitted to the transmission circuits 27, 28, 29 and 30.
Have exchanged with each other via. In each of the control devices 4A and 4B, the output of the constant current control circuit 9A (9B) of the own device and the output of the constant current control circuit 9B (9A) of the partner device are input to the parameter correction circuits 31A and 31B, and the parameter correction circuits 31A and 31B are input. The constant voltage control circuit 10A of its own device is provided for 32A and 32B.
Output of (10B) and constant voltage control circuit 10B of partner device
The output of (10A) is input. Parameter correction circuit 3
In 1A and 31B, when there are differences in the output values of the two series of constant current control circuits 9A and 9B, the gain constant and time constant of the constant current control circuits 9A and 9B are corrected. Similarly, the parameter correction circuits 31A and 31B also correct the gain constants and time constants of the constant voltage control circuits 10A and 10B when there are differences in the output values of the two series of constant voltage control circuits 10A and 10B. As a result, the correction is made so that the output difference between the two control devices 4A and 4B becomes small.

The selection circuits 16A and 16B select from the outputs of the constant current control circuits 9A and 9B and the constant voltage control circuits 10A and 10B and the constant margin angle control circuits 11A and 11B corrected in this way. Since the signals are already in a state of substantially matching between the two control devices 4A and 4B, they are input to the phase control circuits 19A and 19B without re-checking, and the timing of the gate pulse is determined there. . This timing signal is sent to the gate pulse generator 5, a gate signal based on the timing is output from the gate pulse generator 5, and the thyristor converter 2 is controlled.

As described above, in the two control devices 4A and 4B, the constant current control is performed according to the difference between the output values of the constant current control circuits 9A and 9B and the difference between the output values of the constant voltage control circuits 10A and 10B. Circuits 9A and 9B and constant voltage control circuit 10
By changing the parameters and initial values of A and 10B, the constant current control circuits 9A and 9B and the constant voltage control circuit 10A of both systems are changed.
Since the deviations of the parameters and structure of 10B are corrected so that the output values of both systems match, it is possible to construct a system without problems even if the outputs of both systems are not exchanged and collated each time.

In the above embodiment, the gain constant and the time constant are shown as examples of the parameters to be modified, but the parameters of other constituent elements may be modified.

Example 3. Next, still another embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a block diagram showing the configuration of a control device to which the control method for an AC / DC converter according to the third embodiment is applied. Corresponding parts are designated by the same reference numerals as in FIG. 1 and their description is omitted. In the figure, 33A and 33B are determination circuits for determining whether the system is normal or abnormal by taking in both the outputs of the constant current control circuits 9A and 9B exchanged with each other via the transmission circuits 27 and 28. , 34B
Is an output contact of the discrimination circuits 33A and 33B. 35
Reference numerals A and 35B are determination circuits that take in both the outputs of the constant voltage control circuits 10A and 10B exchanged with each other via the transmission circuits 29 and 30 and determine whether the system is normal or abnormal, and 36A and 36B are These are output contacts of the discrimination circuits 35A and 35B. In addition, these discrimination circuits 33A, 33B,
35A and 35B determine that one system is abnormal when the difference between the captured output values is large, when one of them has no output, or when the output value is oscillating, and its output contact 3
4A, 34B, 36A, 36B are opened.
The control devices 4A, 4B according to the third embodiment include the determination circuits 33A, 33B and 35A, 35B.
It is different from the first embodiment in which the same reference numerals are assigned in FIG. 1 in that the output contacts 34A, 34B and 36A, 36B are provided.

Next, the operation will be described. Also in this case, as in the case of the first embodiment, in the two control devices 4A and 4B, the outputs of the constant current control circuits 9A and 9B and the outputs of the constant voltage control circuits 10A and 10B are transmitted to the transmission circuits 27 and 28, respectively.
They are mutually exchanged via 29 and 30. Each control device 4
In A and 4B, the output values of the exchanged constant current control circuits 9A and 9B are input to the adders 21A and 21B with opposite polarities and also to the determination circuits 33A and 33B. The outputs of the adders 21A and 21B are input to the constant current control circuit correction control circuits 22A and 22B having a large time constant, and the correction signals output from the constant current control circuit correction control circuits 22A and 22B are determined. Output contacts 34 of circuits 33A and 33B
It is input to the adders 23A and 23B via A and 34B.

On the other hand, in the discriminating circuits 33A and 33B, when the difference between the two output values inputted is large, when one side has no output,
Furthermore, when the output is oscillating, it is discriminated, and in those cases, it is considered that one system is abnormal, and the output contact 34
A and 34B are opened, and the correction signals from the constant current control circuit correction control circuits 22A and 22B are added to the adders 23A and 23B.
Please do not give feedback to. Therefore, the correction signals from the constant current control circuit correction control circuits 22A and 22B are input to the adders 23A and 23B only when it is confirmed by the determination circuits 33A and 33B that they are normal, and the difference between the output values of both systems is calculated. A corresponding correction is performed.

Similarly, in each of the control devices 4A and 4B, the output values of the exchanged constant voltage control circuits 10A and 10B are input to the adders 24A and 24B in reverse polarity and also to the determination circuits 35A and 35B. This adder 24A, 24
The output of B is the correction control circuits 25A, 25 for the constant voltage control circuit.
B, and the correction signal is input to the discrimination circuits 35A and 35B.
26A, 26 via the output contacts 36A, 36B of
Input to B. The discriminating circuits 35A and 35B discriminate a case where there is a large difference between the two input output values, a case where one side has no output, and a case where the output is oscillating. In these cases, there is an abnormality in one system. I think that the output contact 36
A and 36B are opened, and the correction signals from the constant voltage control circuit correction control circuits 25A and 25B are added to the adders 26A and 26B.
Please do not give feedback to. Therefore, correction is made according to the difference between the output values of both systems only when it is confirmed to be normal by the determination circuits 35A and 35B.

Thus, in the two control devices 4A and 4B, the constant current control circuits 9A and 9B and the constant voltage control circuit 1 are provided.
When the difference between the output values of 0A and 10B exceeds the specified value, when one system becomes no output, or when there is an abnormal state such as the output vibrating, correction according to the difference between the output values of both systems Since it is stopped, when one system is abnormal and output is ridiculous, it is possible to prevent correcting the normal system in order to match both systems and maintain a normal control system. I am trying. Further, with this configuration, it is possible to continue the normal operation without affecting the partner system even when one system is not producing an output due to a stop or an accident.

Embodiment 4 FIG. Next, still another embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a block diagram showing the configuration of a control device to which the control method for an AC / DC converter according to the fourth embodiment is applied. Corresponding parts are designated by the same reference numerals as those in FIG. 5 and their description is omitted. In the figure, 37A and 37B are storage circuits for storing the previous output values of the selection circuits 16A and 16B, and 38A and 38B are selection circuits 16A and 16B.
It is a comparison circuit for comparing the previous output value of and the output value of this time. 39A and 39B are switching circuits for switching between passing and blocking of the outputs of the selection circuits 16A and 16B according to the outputs of the comparison circuits 38A and 38B, and 40A and 40B are according to the outputs of the comparison circuits 38A and 38B.
7B is a dual system comparison circuit that compares the output values of the selection circuits 16A and 16B exchanged with each other. It should be noted that the control devices 4A and 4B according to the fourth embodiment are the same as those of the dual system selection circuit 18
Instead of A and 18B, these storage circuits 37A and 37B,
The comparison circuits 38A and 38B, the switching circuits 39A and 39B, and the dual system comparison circuits 40A and 40B are included.
This is different from the conventional one shown in FIG.

Next, the operation will be described. Each control device 4
In A and 4B, the previous output values of the selection circuits 16A and 16B are stored in the storage circuits 37A and 37B. Comparison circuit 3
8A and 38B compare the current output values of the selection circuits 16A and 16B with the previous output values of the selection circuits 16A and 16B stored in the storage circuits 37A and 37B, and switch the switching circuit 39A according to the difference. , 39B and the dual system comparison circuits 40A, 40B are controlled. That is, if the difference is less than or equal to the set specified value, the switching circuits 39A, 39B
Is made conductive, and the outputs of the selection circuits 16A and 16B of the own device are controlled by the phase control circuit 19 regardless of the output of the other device.
Input to A and 19B. Further, the comparison circuits 38A and 38B
When it is judged that the difference is more than the specified value in,
The outputs of the selection circuits 16B and 16A of the partner device are transmitted to the transmission circuit 1
7A and 17B are exchanged with each other, and after the double system comparison circuits 40A and 40B confirm that the difference between the output values of both systems is within a certain value, the output value is changed to the phase control circuit 19A.
Input to A and 19B.

As described above, since the selection operation is performed only by comparing the previous control output and the present control output possessed by the own device, the difference between the present output and the previous output is defined under normal conditions. If it is within the value, it will be possible to output as it is, it is possible to eliminate the influence of the time delay for exchanging control outputs on the control characteristics, etc., and it is possible to build a stable control system. When an output that greatly deviates from the value is generated, it is possible to prevent a decrease in reliability by checking the output value of the partner device.

[0040]

As described above, according to the first aspect of the present invention, an amount corresponding to the difference between the output values of the control circuits such as the constant current control circuit and the constant voltage control circuit of the self device and the other device is set as follows. Since it is configured to feed back to the input of the control circuit of its own device, correction is performed so that the difference in the output value of each control device becomes small, and it is not necessary to exchange the output of each system and collate each time. The effect that a stable control that is not affected by a time delay can be performed, and even if one system cannot be used due to a failure or the like, a control method for an AC / DC converter that can smoothly switch to a healthy system can be obtained. There is.

According to the second aspect of the invention, the parameter of the control circuit of the own device is modified according to the difference between the output values of the control circuits of the own device and the other device.
It is possible not only to add a correction signal to the input of the control circuit to correct it, but also to correct the configuration by correcting the parameter so that the deviation of the parameter and structure of the control circuit of each system can be eliminated. Since it is not necessary to compare the outputs of the respective systems, there is an effect that a control method of the AC / DC converter capable of performing stable control without being affected by the time delay can be obtained.

According to the third aspect of the invention, the difference in the output values is dealt with only when the normality is confirmed by the discrimination based on the output values of the control circuits of the own device and the other device. Since the quantity is configured to be fed back to the input value of the control circuit of the device itself, when one system becomes abnormal and is sending out a ridiculous output value, it is possible to follow it to correct the normal system. It is possible to obtain the control method of the AC / DC converter, which can prevent the normality of the control system at all times.

Further, according to the invention described in claim 4, the control output is sent out according to the result of comparison with the output value of the other device only when the difference between the previous output value and the current output value in the own device is equal to or more than the specified value. Since it is configured so that it is always judged using the information of its own device, it will not be affected by the time delay, and if the output value greatly deviates from the previous value, the output value of other device will be checked. By doing so, there is an effect that a control method of the AC / DC converter capable of ensuring reliability can be obtained.

[Brief description of drawings]

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

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

FIG. 3 is a block diagram showing a third embodiment of the present invention.

FIG. 4 is a block diagram showing a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a conventional device.

[Explanation of symbols]

4A, 4B control device, 9A, 9B control circuit (constant current control circuit), 10A, 10B control circuit (constant voltage control circuit).

Claims (4)

[Claims] 1. A method of controlling an AC / DC converter, wherein an AC / DC converter is controlled by a multiplexed control device, wherein outputs of respective control circuits of the respective control devices are exchanged with each other, and the control circuit of the own device is exchanged. A method of controlling an AC / DC converter, comprising adding an amount corresponding to a difference between an output value and an output value of the control circuit of another device to an input value of the control circuit. 2. A method of controlling an AC-DC converter, wherein the AC-DC converter is controlled by a multiplexed control device, wherein the output values of the respective control circuits are exchanged between the control devices.
A method of controlling an AC / DC converter, wherein the parameter of the control circuit is modified according to a difference between an output value of the control circuit of the own device and an output value of the control path of another device. 3. A method of controlling an AC / DC converter, wherein an AC / DC converter is controlled by a multiplexed control device, wherein outputs of respective control circuits of the respective control devices are exchanged with each other, and the control circuit of the own device is exchanged. Based on the output value and the output value of the control circuit of the other device, the normality / abnormality of each control device is determined, and only when the normality is confirmed by the determination, the output value of the own device and the other device A method of controlling an AC / DC converter, comprising adding an amount according to a difference to an input value of the control circuit. 4. A method of controlling an AC / DC converter, wherein an AC / DC converter is controlled by a multiplexed control device, wherein each control device compares a previous output value of its own device with a current output value, If the difference between the two is within a specified value, the output value is immediately sent out, and if it is above the specified value, the output value is sent out according to the result of comparison with the output value of another device. Control method.