JPH11150859A - Method and apparatus for controlling operation of direct-current transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the fluctuations in system alternating-current voltage due to the reduction in consumed reactive power by reducing a direct current command value and advancing a control angle of leading. SOLUTION: If a converter 3 is in operation and a series-connected converter 3' is additionally operated, the converter 3' is brought into a bypass pair state (S11, S12), and the direct current command value of the converters is reduced on the transmission side. Further, a control angel of lead β on the receiving side is advanced to a specified value (S13). At some midpoint in the process that the value for the output current of the transmission-side converter 3 is reduced, and the control angle of lead β advances, a bypass switch 5' is opened (S14). When the measured direct current value is reduced to a minimum direct current command value and the control angle of lead reaches a predetermined value (S15, S16), the actuation of the converter 3' is stated both on the transmission side and on the receiving side, and the direct current command value on the transmission side is reduced to half the original value at the same time as starting (S17). When the measured direct current is halved, the control is ended (S18, S19).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control method for suppressing voltage fluctuations of an AC system in consideration of fluctuations in active / reactive power when additionally starting or partially stopping a converter of a DC power transmission device. The present invention relates to an operation control device.

[0002]

2. Description of the Related Art In a DC power transmission device configured by connecting a plurality of AC / DC converters in series, converters connected in series are additionally started and stopped due to failure, inspection, or increase / decrease in power demand of the converters. There is a need. However, the addition of the converter increases the transmission active power and the reactive power consumption of the entire converter, but the fluctuations in the active power and the reactive power cause fluctuations in the AC voltage of the system. . It is desirable to minimize this AC voltage fluctuation.

FIG. 25 is a publication of Japanese Patent Application Laid-Open No. 54-7137.
This is a device configuration of a conventional DC power transmission device disclosed in Japanese Patent Application Laid-Open Publication No. HEI 9-209, which is a common configuration of a power transmission side and a power receiving side, and either one may be a power transmission side or a power receiving side. FIG. 26 shows a control circuit for controlling the converter of the DC power transmission device, and this control circuit is disposed on each of the power transmission side and the power receiving side. FIG.
27 is a time chart in a case where additional activation is performed using the control circuit of FIG.

In FIG. 25, 101, 101 ', 10
2, 102 'is an AC system, 103, 103', 104,
104 'is a converter, 105, 105', 106, 10
6 'is a bypass switch, 107 and 107' are DC reactors, and 108 is a DC line.

In FIG. 26, reference numeral 110 denotes a central command center, 1
11 is a current margin, 112 is a DC current set value, 113
Is a current set value correction control signal, 114 is a current correction value setter, 115 is a switch, 116 is a primary delay circuit, 117
Is a DC amplifier, 118 is a constant margin angle control unit, 119 is a minimum value selection unit, 120 and 120 ′ are voltage limiters, 121 and
121 'is a pulse phase shifter, 122 and 122' are pulse generators, and 123 is a DC current transformer.

In FIG. 27, reference numeral 80 denotes a current command value;
Is a DC voltage, 82 is a reactive power, and 83 is an AC voltage fluctuation amount.

Next, the operation will be described. In FIG. 25, the converters 103 and 103 'are used as converters on the power transmission side, and
4, 104 'is a power receiving side converter. Converter 103,
When the converters of the remaining 103 ′ and 104 ′ are activated while the 104 is operating, the voltage of the AC system may drop sharply and the DC system may not be able to operate stably. It adversely affects excessive stability.

In the prior art, when the converter is additionally started to eliminate this drawback, in order to reduce the reactive power required by the additionally started converter, as shown in FIG. Performed with the command value 80 (Idp) lowered,
The reactive power consumption 82 (Q) at this time decreases as the DC current is reduced, and the AC power fluctuation 83 (ΔVac) is suppressed to enable continuous operation. Note that the DC voltage (Vd), which is the output voltage of the converter, is additionally activated and the converters 3 and 3 '
Are connected in series, so that the voltage is doubled.

[0009]

In the conventional method, the fluctuation of the AC system voltage is reduced by reducing the reactive power consumption. For example, when one additional unit is started during the operation of one unit, the additional start-up is performed. After that, since the DC voltage is doubled, if the current is returned as it is, there is a problem that the active power suddenly doubles before the additional start. In addition, there is a problem that the reactive power also increases abruptly, and is not sufficient for suppressing the fluctuation of the AC system voltage. Further, in the conventional technique, there is a problem that a rise time from a start point of the constant current control is required immediately after the start, and the rise is difficult depending on a time constant.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described drawbacks, and it has been made possible to reduce fluctuations in reactive power consumption, fluctuations in AC system voltage after additional startup, and
An object of the present invention is to provide a start-up method capable of starting up without occurrence of overcurrent immediately after start-up by a limiter of constant current control.

[0011]

(1) An operation control method for a DC power transmitting apparatus according to the present invention is a method for controlling an operation of a DC power transmitting apparatus in which a plurality of converters connected in series are arranged on a power transmission side and a power reception side. In the case where the M converters are additionally activated while the N converters are operating in series, the output DC current values of the N operating converters on the power transmission side are reduced before the M converters are activated. Additional start-up, the output DC current value of the converter operating at the time of this additional start-up and the converter to be additionally started is set to a current value that is approximately N / (N + M) times the output DC current value of the N converters before the decrease. Is controlled.

(2) In an operation control method of a DC power transmitting device in which a plurality of converters connected in series are arranged on a power transmission side and a power reception side, a converter in which a part of the converters is stopped during a serial operation. In the case of additional activation, the output DC current value of the converter on the power transmission side during operation is reduced, and the control lead angle of the converter during operation on the power reception side is increased and then additionally activated. .

(3) In a method for controlling the operation of a DC power transmitting device in which a plurality of converters connected in series are arranged on a power transmission side and a power reception side, a converter in which a part of the converters is stopped during a serial operation. In addition, the output DC current value of the converter on the power transmission side during operation is reduced, and the control lead angle of the converter on the power reception side during operation is adjusted to the value before the output DC current value of the converter during operation. Are additionally activated after a control lead angle corresponding to the DC current value of the control signal.

(4) In the operation control method of a DC power transmitting device in which a plurality of converters connected in series are arranged on a power transmission side and a power receiving side, M converters (N>
When the M) converters are stopped, the M converters to be stopped are put into the bypass pair state, and then the output DC current values of the converters on the power transmission side that are not stopped are approximately N / (N−M) of the current value. The current value is doubled, and then the M converters are stopped.

(5) In the operation control method of a DC power transmitting apparatus in which a plurality of serially connected converters are arranged on the power transmission side and the power receiving side, M converters (N
> M) When the converter is stopped, the output DC current value of the operating converter on the power transmission side is reduced, the M converters to be stopped are put into the bypass pair state, and then the conversion on the power transmission side that does not stop is performed. The output DC current value of the filter is approximately N / (N
-M) times to increase the current value and then stop the M converters.

(6) A method for controlling the operation of a DC power transmitting apparatus in which a plurality of converters connected in series are arranged on a power transmission side and a power receiving side, wherein a part of the converters are stopped during a serial operation. Additional startup, the output DC current value of the converter on the power transmission side during operation is reduced by a predetermined time constant, and the control lead angle of the converter on the power reception side during operation is substantially the same as the predetermined time constant. After the time constant has been increased, additional startup is performed.

(7) In the operation control method of a DC power transmitting device in which a plurality of serially connected converters are arranged on the power transmission side and the power receiving side, the control of the output DC current value of the converter on the power transmission side is performed by a constant current. When controlling, the DC current command value by the constant current control is controlled to the converter on the power transmission side via the control angle limiter having the movable limiter characteristic, and a part of the converter is operated in series operation. When additional converters are stopped during startup, the DC current command value of the operating converter on the power transmission side is reduced to reduce the output DC current value, and the control of the operating converter on the power receiving side is advanced. It is designed to additionally start after increasing the corner.

(8) The above (2), (3) and (6)
In any one of the above items (7), during the additional startup, the output DC current value of the operating converter on the power transmission side and the output DC current value of the converter to be additionally activated on the power transmission side are reduced by the output DC current value. The current value is controlled to be N / (N + M) times the current value.

(9) In the above (8), the output DC current value of the operating converter on the power transmission side after the completion of the additional startup is controlled to the current value before the output DC current value decreases. It was made.

(10) An operation control device for a DC power transmission device according to the present invention is an operation control device using the operation control method for a DC power transmission device according to any one of the above (1) to (9). .

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, embodiments of the present invention will be described with reference to the drawings. The configuration of the entire DC power transmitting device is the same as that of the conventional DC power transmitting device shown in FIG. FIG. 1 is a block diagram of a control circuit according to this embodiment. The control circuit is arranged on each of a power transmission side and a power receiving side. FIG. 2 is a time chart when the converter is additionally activated, and FIG. 3 is a flowchart of the control operation.

In FIG. 1, reference numeral 10 denotes an operation controller, 11 denotes a current margin, 12 denotes a DC current command value, 13 denotes an additional start command, 14 denotes a transmission power command value, and 30 denotes a DC current command value 1.
Reference numeral 31 denotes a DC current command value control unit for controlling the DC current command value 12, 32 denotes a first-order lag filter, 33 denotes a constant current control unit, 34 denotes a constant voltage control unit, and 35 and 35 ′ denote control angle limiters. , 18 are constant margin angle control units, 19 is a minimum value selection unit, 21 and 21 'are phase controllers, 22, 22' are pulse generators, 3, 3 'are AC / DC converters, and 5, 5' are bypass switches. , 7 are DC reactors and 23 is a DC current transformer.

Next, the operation will be described. This operation control circuit measures the DC current and DC voltage, feeds back the values, and calculates the control angle based on the measured values. During a steady operation, the constant current control unit 33 is selected on the power transmission side, and the power reception is performed. On the side, the constant voltage control unit 34 or the constant margin angle control unit 18 is designed to be selected.

(1) It is assumed that the AC / DC converters 3 'on the power transmitting side and the power receiving side are stopped, and the AC / DC converters 3' on the power transmitting side and the power receiving side are additionally activated on the assumption that the AC / DC converters 3 are already operating on the power transmitting side and the power receiving side, respectively. S1). (2) On both the power transmission side and the power receiving side, the AC / DC converter 3 ′ is set to the bypass pair state by the additional start command (S2).

(3) On the power transmission side, the DC current command value limiter 3
0 is the DC current command value used so far (see FIG. 2, 80
From the Idp a) of (1) to the minimum DC current command value (b in FIG. 2, 80) for reducing the consumed reactive power (Sd).
3). Here, the minimum DC current command value is usually about 1/10 of the rated current.

(4) The minimum DC current command value is input to the adder 36 via the first-order lag filter 32, and the output current value of the converter 3 on the power transmission side is reduced. The switch 5 'is opened (S4).

(5) Further, the output current of the converter 3 on the power transmission side decreases (S5), and (6) it is confirmed by the DCCT 23 that the actually measured current value has decreased to this minimum current command value (S6). (7) If it has decreased, the converter 3 'to be added to both the power transmitting side and the power receiving side is set in the DEB state (deblocking state in which a firing pulse is output to the thyristor valve), and activation is started. At the same time as the startup, the DC current command value on the power transmission side is set to half of the initial DC current command value (80 in FIG. 2) so that the active power after the additional startup is made equal to the power before the additional startup by the DC current command value control unit 31. C) (S7).

(8) When the measured DC current value increases according to the DC current command value and becomes half of the initial value, the control is terminated (S
8, S9). In this case, the reactive power value (Q) is suppressed as compared with 82 in FIG. As a result, the AC voltage fluctuation (Δ) decreases as indicated by 83 in FIG.

The case where two converters are connected in series has been described above. However, when M converters are additionally activated from a state in which N converters are operated, the DC current after activation is increased. The same effect can be obtained by setting the command value (Idp ') to a value obtained by multiplying the initial DC current command value (Idp) by N / (N + M) as shown in Expression (1). Idp ′ = [N / (N + M)] · Idp (1) In the case of the additional startup in the following embodiments,
Equation (1) can be applied.

As described above, after the DC current command value of the operating AC / DC converter is reduced, the DC / DC converter is additionally started, and thereafter the DC current command value is reduced according to the number of converters to be operated / added in series. As a result, additional startup with reduced voltage fluctuation can be realized.

Embodiment 2 FIG. 4 shows a control block diagram for realizing the second embodiment. FIG. 5 is a time chart when the converter is additionally activated, and FIG. 6 is a flowchart of the control operation.

In FIG. 4, reference numeral 40 denotes a start signal, 41 denotes an additional start signal, 42 denotes a signal indicating that the power is on the receiving side, 43 denotes a predetermined value when the control advance angle β is advanced, 44
Is a limiter control signal, 45 is a control angle limiter control block for controlling the control angle limiter, and 95 is a control angle limiter control signal.

Next, the operation will be described. (1) The control angle limiters 35 and 35 'are opened from about 90 ° by a signal from a control angle limiter control block 45 for controlling the control angle limiter by a start signal 40 at the time of normal startup, and return to about 90 ° at the time of stop. I do.

(2) It is assumed that the AC / DC converters 3 on the power transmission side and the power receiving side are already operating, and the AC / DC converters 3 ′ on the power transmission side and the power receiving side are stopped and are additionally activated ( S11). (3) On both the power transmission side and the power receiving side, the AC / DC converter 3 ′ is set to the bypass pair state by the additional start command (S12).

(4) On the power transmission side, the additional start signal 4
1 to output the limiter control signal 44 to limit the DC current command value limiter 30 to the minimum current command value in order to reduce the reactive power consumption, and at the same time, on the power receiving side, the control angle limiter 35 sets the control advance angle β to a predetermined value. The value is advanced to the value (S13) (see 84 in FIG. 5).

(5) The minimum DC current command value is input to the adder 36 via the primary delay filter 32, so that the output current value of the converter 3 on the power transmission side decreases and the control advance angle β is advanced. While the output current is decreasing, the bypass switch 5 'is opened (S14). (6) Further, the output current of the converter 3 on the power transmission side decreases, and the control advance angle β advances (S15).

(7) After confirming that the DC current measured value has reached the minimum value by the DCCT 23 and that the control advance angle β has reached the predetermined value (S16), (8) both the power transmission side and the power reception side The converter 3 'is set to the DEB state (a deblocking state in which a firing pulse is output to the thyristor valve), and additional activation is started. At the same time as the startup, the DC current command value on the power transmission side is reduced to half of the initial value in order to return to the transmission power before the additional startup (S17).

(9) When the measured DC current value increases according to the DC current command value and becomes half of the initial value, the control is terminated (S
18, S19).

In FIG. 5, reference numeral 84 denotes a control lead angle (β), which reduces the DC current command value (Idp) and
By adding the advance, it is possible to reliably suppress the AC system voltage fluctuation due to the reduction of the reactive power consumption.

Embodiment 3 FIG. 7 is a control block diagram for realizing the third embodiment, FIG. 8 is a time chart when the converter is additionally activated, and FIG. 9 is a flowchart of the control operation. In FIG. 7, reference numeral 46 denotes a timer, which is obtained by adding the timer 46 to FIG. 4 of the second embodiment.

Next, the operation will be described. (1) Steps S21 to S26 are the same as steps S11 to S16 in FIG. 6 of the second embodiment, and are executed.

(2) In step S26, when the measured DC current value reaches the minimum DC current command value and the control lead angle β reaches a predetermined value, both the power transmitting side and the power receiving side convert the converter 3 '.
Is set to a DEB state (a deblocking state in which a firing pulse is output to the thyristor valve), and additional activation is started. At the same time as the startup, the DC current command value on the power transmission side is reduced to half of the initial value in order to return to the transmission power before the additional startup. At the same time, the timer 46 is started on the power transmission side (or power reception side) (S2).
7). The timer 46 is started at time t1 of 80 in FIG. 8 and times out after T time.

(6) The measured DC current value increases according to the DC current command value (S28). (7) The timer 46 is set so as to time up when the measured DC current value becomes half of the initial value (at time t2 of 80 in FIG. 8), and when the timer 46 times out (S29), 8) The DC current command value is increased to the initial value and the converter 3 '
Output current value as its command value and output power
The control is terminated (S30).

As described above, by reducing the DC current command value on the power transmission side and advancing the control advance angle β on the power reception side, the decrease in the reactive power consumption is compensated for. Is reduced to half and the DC current value is returned to the initial value again after a certain period in which the DC current value is reduced to half before the additional activation, so that there is an effect that the transmission power can be smoothly increased.

It should be noted that the timer may be started at time t0 of 80 in FIG. 8 and timed out at time t2.

Embodiment 4 FIG. FIG. 10 is a control block diagram for realizing the fourth embodiment, FIG. 11 is a time chart when the converter is additionally activated, and FIG. 12 is a flowchart of the control operation. In FIG. 10, reference numeral 91 denotes a control angle limiter control block, which takes in a DC current and advances the control angle in accordance with the DC current.
A control angle control signal 95 for controlling 35 'is transmitted.

The operation will be described. (1) Steps S41 to S43 are the same as steps S1 to S3 in FIG. 3 of the first embodiment and are executed. (2) The control angle limiter control block 91 on the power receiving side sets the control advance angle β to the optimal advance angle in accordance with the measured DC current value before the output DC current value is reduced from the input DCCT 23,
The control angle limiter 35 is controlled to advance to the optimum advance angle (S44).

(3) The minimum DC current command value is input to the adder 36 via the primary delay filter 32 to reduce the output DC current value of the converter 3 on the power transmission side and to advance the control advance angle β. . While the output current is decreasing, the bypass switch 5 'is opened (S45).

(4) Further, the output current of the converter 3 on the power transmission side decreases, and the control advance angle β advances (S46). (5) The measured DC current value decreases to the minimum DC current value, and the control advances. When the angle β becomes the optimum advance angle (S47), (6) both the power transmitting side and the power receiving side start the activation of the converter 3 ′. At the same time as the startup, the DC current command value on the power transmission side is reduced to half of the initial DC current command value by the DC current command value control unit 31 so that the active power after the additional startup is the same as the power before the additional startup ( S48).

(7) When the measured DC current value increases according to the DC current command value and becomes half of the initial value, the control is terminated (S
49, S50).

By controlling the control angle, it is possible to set an optimum advance value in accordance with the current value of the transmission current, thereby preventing the generated reactive power from becoming excessive. Judgment of this value is based on the percentage of system AC voltage fluctuation in steady state operation.
It is determined depending on whether it is kept within.

For example, as shown in FIG. 11, the dotted line (a) and broken line (b) of the current command value and the control lead angle correspond to each other, and the value of β is changed depending on the DC current command value. .

As described above, the optimum value of β advance is determined based on the result of actually measuring the DC current value.
There is an effect that an optimum additional activation according to the power transmission state can be realized.

Embodiment 5 FIG. Embodiments of the present invention
This is control when a part of converters connected in series is stopped. FIG. 13 is a control block diagram for realizing the partial stop according to the fifth embodiment, FIG. 14 is a time chart when the converter is partially stopped, and FIG. 15 is a flowchart of the control operation. In FIG. 13, 47 is a partial stop command, 48
Denotes a current command value control unit.

Next, the operation in the case of application at the time of partial stop will be described. (1) The converter 3 and the converter 3 'are both operating on the power transmission side and the power reception side (S60). (2) The DC current limiter 30 on the power transmission side is limited to the minimum current command value by the partial stop signal 47. (S61).

(3) When the measured DC current value reaches the minimum DC current command value (S62), (4) The control angle limiter 35 'of the converter 3' which stops on both the power transmission side and the power reception side sets the control angle to 90. Control each time (S6
3).

(5) The converters 3 'on the power transmission side and the power reception side are set to the bypass pair state (S64). (6) The DC current command value of the operating converter 3 on the power transmission side is set to 2
Double (within the rated value) (S65). (80 in FIG. 14)

(7) The doubled DC current command value is input to the adder 36 via the one-hour delay filter 32, and the output current of the power transmitting side converter 3 is increased (S66). (8) While the output current value of the power transmission side converter is increasing, the bypass switch 5 'is turned on. (S67)

(9) Further, if the output current value of the converter 3 increases and the measured DC current increases to twice the DC current command value (S68, S69), (10) both the power transmission side and the power reception side Stop the converter 3 '(S
70).

The reason for doubling the measured DC current is that if it is not doubled, the DC voltage value is halved and the transmission power is also halved, which may cause fluctuations in the power system and cause an unstable situation. To prevent this, the DC current command value is doubled, and as long as this value does not exceed the rated value, the same transmission power as before the partial stop can be secured, and the influence on the power system can be reduced. Thereafter, the current command value may be changed according to the target transmission power.

Here, the case where one unit is stopped from the operation of two units is described, and the DC current command value is doubled.
When M units are stopped during operation, the DC current command value (Id
p ′) is calculated from the initial value (Idp) by N, as in equation (2).
The same effect can be obtained by setting the value to be multiplied by / (N−M). Idp '= [N / (N−M)] · Idp −−−−−−− (2)

As described above, in the case of partial stop, the DC current command value is doubled (or N / (NM) times), and the DC current value is doubled (or N / ( NM))
After a certain period of time, the converter was stopped, and the converter was moved to the desired DC current command value.
In the case of partial stop, there is an effect of providing a means that can be executed without giving any disturbance to the system.

In the flowchart of FIG.
Although the output current value of the converter is reduced to the minimum current instruction value in steps S61 and S62, these steps may not be executed, and the process may jump from step S60 to step S63 and execute. Although the voltage fluctuation value on the AC side increases to some extent, the fluctuation of the system can be reduced by doubling the DC current command value after step S65.

Embodiment 6 FIG. FIG. 16 is a control block diagram for realizing the sixth embodiment, FIG. 17 is a time chart when the converter is additionally activated, and FIG. 18 is a flowchart of the control operation. In FIG. 16, reference numeral 50 denotes the operation controller 1
Time constant command value output from 0.

The operation will be described. (1) It is assumed that the AC / DC converter 3 on the power transmission side and the power receiving side are already operating and the AC / DC converter 3 ′ on the power transmission side and the power receiving side are stopped and are additionally activated (S71). (2) On both the power transmission side and the power receiving side, the AC / DC converter 3 ′ is set to the bypass pair state by the additional start command (S72).

(2) On the power transmission side, the additional activation signal 41
As a result, the DC current command value limiter 30 limits the DC current command value to the minimum DC current command value, and on the receiving side, the time constant command value 50 reduces the DC current command value by the primary delay filter 32 after the DC current command value limiter 30. And the time constant for causing the control advance angle β by the control angle limiter control block 91 ′ to advance to a predetermined value are set to the same time constant (τ) (S73).

In this manner, the measured DC current value and the control advance angle β are measured without confirming that they have reached the predetermined values, and can be determined from the time constant (τ). After T1), additional activation can be started. (80, 84 in FIG. 17)

(3) The minimum DC current command value is input to the adder 36 via the first-order lag filter 32, the output current value of the converter 3 decreases, and the control advance angle β advances. While the output current value is decreasing, the bypass switch 5 'is opened (S7).
4).

(4) Further, the output current value of the converter 3 on the power transmission side decreases, and the control advance angle β advances, and the time constant (τ)
After a lapse of a predetermined time (time T1) derived from
5, S76), (5) Both the power transmission side and the power receiving side start the activation of the converter 3 ′,
At the same time as the activation, the DC current command value on the transmission side is reduced to half of the initial value (S77).

(6) When the measured DC current value increases according to the DC current command value and becomes half of the initial value, the control is terminated (S
78, S79).

As described above, by making the time constant for decreasing the DC current command value equal to the time constant for increasing β, the time constant of the control circuit can be obtained without checking the current of the main circuit. There is an effect that the control time can be controlled.

Embodiment 7 FIG. In the seventh embodiment, after the sixth embodiment is executed, the DC current command value is returned to the initial value, and the transmission power is doubled.

FIG. 19 is a control block diagram for realizing the sixth embodiment, FIG. 20 is a time chart when additional activation of the converter is performed, and FIG. 21 is a flowchart of the control operation. In FIG. 19, 50 is a time constant set value, and 51 is a current command value / β advance command recovery command.

(1) As in the case of the sixth embodiment, the same time constant 50 is passed to the first-order lag filter 32 after the current command value limiter 30 on the power transmission side and the control angle limiter control 41 on the power reception side. By doing so, the additional activation can be started after a time (T1 time) that can be determined from the time constant without measuring the value of the measured DC current value and the value of the control lead angle β (see the sixth embodiment). (Same as steps S71 to S76),

(2) On both the power transmission side and the power receiving side, the converter 3 'is additionally activated. The DC current command value at the time of additional startup is reduced to half of the initial value (S77).

(3) After the additional startup, the recovery command 51 indicating the time (Ts time) until the recovery (the measured DC current value is reduced to half of the initial value) is transmitted to the current command value control unit 31 on the power transmission side and the recovery command 51 on the power reception side. By inputting to both of the control angle limiter controls 91 ", the DC current command value after the additional startup is returned to the initial value (S81). In this way, the timing can be coordinated. This timing Ts For the time, usually use a timer, start the timer at the same time as the additional start of the converter,
The time is up after Ts time.

(4) When the DC current command value after the additional startup is returned to the initial value, the measured DC current value (the output current value of the converter 3 on the power transmission side) increases according to the DC current command value ( S8
2), (5) When the measured DC current value reaches the initial value, the process ends (S83).

The time chart at this time is shown in FIG. 20, and the DC current command value is increased to the initial value at Ts end time t2 of 80 and 84.

As described above, the transmission power is increased with the DC current command value as the initial value after a certain period during which the additional startup is stabilized, so that the transmission power can be smoothly increased. effective.

Embodiment 8 FIG. FIG. 22 is a control block diagram for realizing the eighth embodiment, and FIG. 23 is a characteristic diagram of the control angle limiter, where (a) shows the characteristics on the power transmission side and (b) shows the characteristics on the power reception side. In FIG. 22, 35 ″ of the constant current control unit 33 is a control angle limiter having the same function (movable limiter) as the control angle limiter 35, and the output of this limiter is the constant current control unit 3
3 has been fed back.

The operation will be described. On the power transmission side, the control angle output from the constant current control unit 33 is passed through a movable limiter 35 ″ equivalent to the control angle limiters 35 and 35 ′, so that the constant current is output from the initial stage. The movement during the period until the control actually shows the control effect can be stabilized, and the control can be smoothly performed by controlling with the control angle limiter 35 ″ having the characteristics shown in FIG. .

In FIG. 22, the feedback output from the control angle limiter 35 ″ to the constant current control unit 33 does not start at a control angle of 0 ° at the time of startup, but starts at about 90 ° (eg, 85 °) for stable operation. It is to make it.

In FIG. 24, in the constant current control,
When the control angle limiter 35 ″ is provided, the control angle limiter 3
5, 35 'do not have to have the same characteristics. However, in the case of control by the constant margin angle control unit 18 and the constant voltage control unit 34, control angle limiters 35 and 35 'are required.

Embodiment 9 FIG. In the ninth embodiment, in addition to the eighth embodiment, the DC current command value is returned to the initial value, and the transmission power is doubled. FIG. 24 shows a control block diagram for implementing the ninth embodiment. In the figure, 52 is a command for returning the DC current command value to the initial value.

The operation will be described. On both the power transmitting side and the power receiving side, the control angle output from the constant current control unit 33 is set via the same movable limiters as the control angle limiters 35 and 35 ', so that the control angle is fixed from the beginning of startup. The movement of the time until the current control actually shows the control effect can be stabilized. Thereby, it is possible to start up smoothly. The operation so far is the same as that of the eighth embodiment.

In addition to the operation of the eighth embodiment, a command 52 for returning the DC current command value to the initial value after the start of the start is given by
Controls the timing of switching to the initial DC current command value. In this way, there is an effect that smooth control can be realized for the entire period from immediately after the additional startup to the increase in power.

The timing is controlled using a timer or the like as in the third and sixth embodiments.

Embodiment 10 FIG. In the third embodiment, the DC power command value at the time of additional startup is reduced to half of the initial value, and the power is transmitted.
However, even when β is changed according to the output current value of the converter of the fourth embodiment, the transmission power may be increased by setting the DC current command value to the initial value after the additional startup is stabilized. Good.

Embodiment 11 FIG. In the case of determining a value to advance β according to the measured DC current value of the fourth embodiment,
The control angle limiter 35 ″ of the eighth embodiment may be provided to stabilize the startup. That is, the features of both the fourth and eighth embodiments can be provided.

In the case where the time constant for reducing the DC current command value in the sixth embodiment is made equal to the time constant for increasing β, the control angle limiter 35 ″ of the eighth embodiment is provided. In other words, it is possible to stabilize the start-up, that is, it is possible to provide the features of the sixth embodiment and the eighth embodiment together.

[0091]

As described above, according to the present invention, it is possible to suppress the fluctuation of the system AC voltage from increasing due to a decrease in the reactive power consumption when the converter is additionally started. In addition, even in the case of a partial stop, the fluctuation of the system AC voltage can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of a control circuit of a converter of a DC power transmitting device according to Embodiment 1 of the present invention.

FIG. 2 is a time chart of additional activation of the converter according to the first embodiment of the present invention.

FIG. 3 is a flowchart of additional activation of the converter according to the first embodiment of the present invention.

FIG. 4 is a block diagram of a control circuit of a converter of a DC power transmitting device according to Embodiment 2 of the present invention.

FIG. 5 is a time chart of additional activation of the converter according to the second embodiment of the present invention.

FIG. 6 is a flowchart of additional activation of a converter according to Embodiment 2 of the present invention.

FIG. 7 is a block diagram of a control circuit of a converter of a DC power transmitting device according to Embodiment 3 of the present invention.

FIG. 8 is a time chart of additional activation of a converter according to Embodiment 3 of the present invention.

FIG. 9 is a flowchart of additional activation of a converter according to Embodiment 3 of the present invention.

FIG. 10 is a block diagram of a control circuit of a converter of a DC power transmitting device according to Embodiment 4 of the present invention.

FIG. 11 is a time chart of additional activation of a converter according to a fourth embodiment of the present invention.

FIG. 12 is a flowchart of additional activation of a converter according to Embodiment 4 of the present invention.

FIG. 13 is a block diagram of a control circuit of a converter of a DC power transmitting device according to Embodiment 5 of the present invention.

FIG. 14 is a time chart of a partial stop of a converter according to a fifth embodiment of the present invention.

FIG. 15 is a flowchart of additional activation of a converter according to Embodiment 5 of the present invention.

FIG. 16 is a block diagram of a control circuit of a converter of a DC power transmitting device according to Embodiment 6 of the present invention.

FIG. 17 is a time chart of additional activation of the converter according to the sixth embodiment of the present invention.

FIG. 18 is a flowchart of additional activation of a converter according to Embodiment 6 of the present invention.

FIG. 19 is a block diagram of a control circuit of a converter of a DC power transmitting device according to Embodiment 7 of the present invention.

FIG. 20 is a time chart of additional activation of the converter according to the seventh embodiment of the present invention.

FIG. 21 is a flowchart of additional activation of a converter according to Embodiment 7 of the present invention.

FIG. 22 is a block diagram of a control circuit of a converter of a DC power transmitting device according to an eighth embodiment of the present invention.

FIG. 23 is a characteristic diagram of a control angle limiter according to Embodiment 8 of the present invention.

FIG. 24 is a block diagram of a control circuit of a converter of a DC power transmitting device according to Embodiment 9 of the present invention.

FIG. 25 is a block diagram of a device configuration of a conventional DC power transmission device.

FIG. 26 is a block diagram of a control circuit of a converter of a conventional DC power transmission device.

FIG. 27 is a time chart of additional startup of a converter of a conventional DC power transmission device.

[Explanation of symbols]

3,3 'Single converter 5,5' Bypass switch 7 DC reactor 10 Operation controller 11 Current margin 12 DC current command value 13 Additional start command 14 Transmission power command value 18 Constant margin angle control unit 19 Minimum value selection unit 21, 21 'phase controller 22, 22' pulse generator 23 DC current transformer 30 current command value limiter 31 current command value control unit 32 first order lag filter 33 constant current control unit 34 constant voltage control unit 35, 35 ', 35 "control Angle limiter 36 Adder 40 Start signal 41 Additional start signal 42 Signal indicating that the power is on the receiving side 43 Predetermined value when the control advance angle β is advanced 44 Limiter control signal 45 Control angle limiter control block 46 Timer 47 Partial stop command 48 Current command value control unit 50 Time constant command value 51 Current command value / β advance command recovery command 52 DC power Command to restore command value 60, 60 'Maximum value of control angle limiter 61, 61' Minimum value of control angle limiter 80 Current command value 81 DC voltage 82 Reactive power 83 AC voltage fluctuation 84 Control advance angle 91, 91 ' , 91 ", 94, 94 'control angle limiter control block 95 control angle limiter control signal

Claims (10)

[Claims] 1. An operation control method for a DC power transmitting apparatus in which a plurality of converters connected in series are arranged on a power transmission side and a power reception side, wherein M converters are additionally activated while N converters are operating in series. In this case, the output DC current values of the N operating converters on the power transmission side are reduced, and then the M converters are additionally activated, and at the time of the additional activation, the operating converter and the additionally activated converter are activated. Wherein the output DC current value is controlled to be approximately N / (N + M) times the output DC current value before the decrease of the N converters. . 2. A method for controlling the operation of a DC power transmission device in which a plurality of converters connected in series are arranged on a power transmission side and a power reception side, wherein a part of the converters additionally activates a stopped converter during the series operation. In the case of the DC transmission device, the output DC current value of the converter during operation on the power transmission side is reduced, and the control lead angle of the converter during operation on the power reception side is increased and then additionally activated. Operation control method. 3. A method for controlling the operation of a DC power transmitting device in which a plurality of serially connected converters are arranged on a power transmission side and a power reception side, wherein a part of the converters additionally activates a stopped converter during series operation. In this case, the output DC current value of the converter during operation on the power transmission side is reduced, and the control advance angle of the converter during operation on the power reception side is changed to the DC value before the output DC current value of the converter during operation. An operation control method for a DC power transmission device, wherein the DC power transmission device is additionally started after a control lead angle according to a current value. 4. A method for controlling the operation of a DC power transmission device in which a plurality of converters connected in series are arranged on a power transmission side and a power reception side, wherein M (N> M) of N converters are in series operation. When the converters are stopped, after the M converters to be stopped are put into the bypass pair state, the output DC current value of the converter on the power transmission side that does not stop is changed to a current of approximately N / (N−M) times the current value. A method of controlling the operation of the DC power transmitting device, wherein the M converters are stopped after that. 5. An operation control method for a DC power transmitting device in which a plurality of serially connected converters are arranged on a power transmission side and a power receiving side, wherein M (N> M) N converters are connected in series. When the converter is stopped, the output DC current value of the operating converter on the power transmission side is reduced, and the M converters to be stopped are put into the bypass pair state. The operation of the DC power transmission device, wherein the current value is increased to a current value approximately N / (NM) times the current value before the decrease, and then the M converters are stopped. Control method. 6. An operation control method for a DC power transmitting device in which a plurality of converters connected in series are arranged on a power transmission side and a power reception side, wherein a part of the converters additionally activates a stopped converter during a serial operation. In this case, the output DC current value of the converter on the power transmission side during operation is reduced by a predetermined time constant, and the control lead angle of the converter on the power reception side during operation is substantially the same as the predetermined time constant. An operation control method for a DC power transmission device, wherein the operation is additionally started after the increase in the number. 7. An operation control method for a DC power transmission device in which a plurality of converters connected in series are arranged on a power transmission side and a power reception side, wherein the output DC current value of the power transmission side converter is controlled by a constant current control. When the DC power command value by the constant current control is controlled through the control angle limiter having the movable limiter characteristic, the converter on the power transmission side is controlled, and a part of the converter stops during the series operation. When starting additional converters inside,
The direct current command value of the operating converter on the power transmission side is reduced to reduce the output DC current value, and the control lead angle of the operating converter on the power receiving side is increased and then additionally activated. An operation control method for a DC power transmission device, comprising: 8. The operation control method for a DC power transmitting device according to claim 2, wherein during the additional startup,
The output DC current value of the converter on the power transmission side during operation and the output DC current value of the converter to be additionally activated on the power transmission side are set to a current value N / (N + M) times the current value before the output DC current value decreases. An operation control method for a DC power transmission device, wherein the operation is controlled. 9. The operation control method for a DC power transmission device according to claim 8, wherein the output DC current value of the operating converter on the power transmission side after the completion of the additional startup is a current value before the output DC current value decreases. An operation control method for a DC power transmission device, characterized in that the operation is controlled in the following manner. 10. An operation control device for a DC power transmission device using the operation control method for a DC power transmission device according to any one of claims 1 to 9.