JPH07336892A - Method and equipment for controlling self-excited dc transmission facility - Google Patents

Abstract

PURPOSE:To provide a control system of DC transmission facilities inhibiting the variation of DC voltage with the change of the command of transmission power and capable of stably controlling transmission power and DC voltage at high speed. CONSTITUTION:ACs are converted into DCs by a converter 31 on the transmission side, and DCs are converted into ACs by a converter 32 on the receiving side through a DC circuit 41. Each converter is composed of elements having a self-extinguishing function. Converter control sections 310, 320 have power control circuits and voltage control circuits respectively, and select one function by a tidal-current direction command from an operation command device 300. The converter control section 320 controls the transmission power of the converter 32 according to the power deviation of a power command and the measured value of a power detecting means 323. The converter control section 310 controls the converter 31 so that the DC voltage Vf of a power capacitor 40 is kept constant according to the voltage deviation of a voltage command x and a voltage detector 311 and the above-mentioned power deviation (or the power command).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-excited DC power transmission equipment composed of two power converters composed of elements having a self-extinguishing function, and in particular, it controls DC power transmission power at high speed and stably. Control method.

[0002]

2. Description of the Related Art In recent years, DC power transmission systems have been successively applied to long-distance power transmission and power source interchange. In particular, DC power transmission equipment using a self-exciting converter is capable of transmitting power to the AC system at the time of power loss and can control any reactive power, either advanced or delayed, which is in high demand.

Self-excited converters can be equivalently placed with a voltage source. Therefore, when an accident occurs at the near end of the converter, a fault current flows from the converter to the fault point, and when the fault current is large, the converter may be broken and the DC power transmission system may stop.

In order to prevent this, JP-A-4-367
As disclosed in 011 publication, the current of a self-excited converter is converted into two axes of dq, that is, divided into two axes of an active component (real current) and a reactive component (imaginary current), and the current of the converter is divided. The inventors of the present invention have proposed a method of controlling the high speed.

Further, a basic control system of a DC power transmission device to which the control method of the self-excited converter is applied is disclosed in Japanese Unexamined Patent Publication No.
It is disclosed in Japanese Patent Publication No. 211779. This is a method of controlling the effective voltage of the current by controlling the DC voltage of the DC circuit with the forward converter to a constant value and controlling the received power with the inverse converter according to the command value. There is a merit that the operation can be performed without knowing the forward converter, that is, without exchanging signals between the forward converter and the inverse converter.

The operating principle of this control system is to inject the voltage change of the DC circuit which occurs when the power is controlled by the inverse converter, by injecting the power equivalent to the change into the DC circuit from the forward converter, that is, the DC circuit. The DC voltage is kept constant by automatically balancing the input and output of electric power. This will be described below using mathematical expressions.

Now, assuming that the capacitor capacity of the DC circuit is C, the transmission power sent from the inverse converter to the AC system is Pd, and the DC voltage of the DC circuit is Vd, the current Ii flowing through the inverse converter is Ii.
Becomes (Equation 1) shown below.

[0008]

## EQU1 ## Ii = Pd / Vd When the current flowing from the forward converter to the DC circuit is set as Ir and the loss of the DC circuit is ignored, the DC voltage Vd becomes (Equation 2).

[0009]

[Expression 2] Vd = 1 / C∫ (Ir-Ii) dt As described above, the DC current Ii flowing into the inverse converter is obtained from the power command value by (Equation 1), and the DC current Ir flowing out from the forward converter is forward. It is inevitably determined from (Equation 2) by controlling the DC voltage of the converter constant. Therefore, stable operation of the DC power transmission system becomes possible by controlling the DC voltage with the forward converter and controlling the transmitted power with the inverse converter.

[0010]

In the above prior art,
As is clear from (Equation 2), since the DC voltage is determined by the time integration of the current, even if the specified power is sent to the AC side by the inverse converter, it does not immediately appear in the change of the DC voltage. Therefore, the inflow of the current required to keep the DC voltage constant from the forward converter is delayed, and the DC voltage fluctuates. In addition, the transmitted power also fluctuates.

As a countermeasure against this, it can be considered to improve the response of the DC voltage control system. However, further increasing the gain of the DC voltage control system is close to the limit in view of the stability of the control system, and it is difficult to stabilize the response of the transmission power control quickly.

An object of the present invention is to provide a control method and apparatus capable of controlling transmitted power and DC voltage at high speed and stably in a self-excited DC power transmission facility.

Another object of the present invention is to provide a flexible control device capable of arbitrarily selecting the transmission power control and the DC voltage control in accordance with the operation mode of the converter in the DC power transmission equipment capable of transmitting power in both directions by power flow reversal. To provide.

[0014]

According to the present invention, an alternating current is converted into a direct current on the power transmitting side and a direct current is converted to an alternating current on the power receiving side through a direct current circuit, and a direct current is transmitted on one side of the power transmitting side or the power receiving side. A control method for a self-excited DC power transmission facility, which controls a DC voltage of a circuit to be constant and controls transmission power on the other side according to a command value, wherein a voltage deviation due to a command value of the DC voltage and an actual measurement value and the transmission power. The DC voltage is controlled to be constant based on the command value or the power deviation between the command value and the measured value.

The present invention comprises a first converter for converting AC into DC on the power transmitting side, a DC circuit including a power capacitor, and a second converter for converting DC into AC on the receiving side. A control device for a self-excited DC power transmission facility, so that the transmitted power on the power receiving side is as a power command value, based on a power control output according to a power deviation between the power command value and its measured value, A power control means for controlling the second converter, and a voltage deviation according to the DC voltage command value of the DC circuit and the measured value thereof and the power command value or the power deviation so that the DC voltage of the DC circuit is constant. Voltage control means for controlling the first converter based on a voltage control output according to the above.

The present invention provides two power converters for sharing a forward conversion from AC to DC and a reverse conversion from DC to AC.
A control device for a self-excited DC power transmission facility comprising a DC circuit connecting the two power converters and a control device for controlling the two power converters, wherein a transmission power command value, a DC voltage command value and A power control means for controlling the transmitted power according to the command value according to the power deviation between the command value of the transmitted power and the actually measured value of the command value of the transmitted power for each of the power converters and the operation command device value that outputs the command value of the flow direction. A unit having a voltage control means for constantly controlling the DC voltage based on a voltage deviation between a voltage command value and an actual measurement value thereof, and a switch means for selecting one of the power control means or the voltage control means according to the power flow direction command. A control device is provided.

Further, in each of the above-mentioned constitutions, the current of the power converter is divided into an active component (real current) and a reactive component (imaginary current).
It is characterized in that the voltage control or the power control is performed as active component current control of the power converter separately for the axes.

[0018]

As an operation of the present invention, consider a case where the forward converter on the power transmitting side controls the voltage of the DC circuit at a constant level and the reverse converter on the power receiving side controls the transmitted power to a specified value. Now, if the power command value to be transmitted from the inverse converter to the AC system is changed, the effective current of the inverse converter is controlled at high speed according to the power deviation generated in the power control system, and the power as commanded is converted to AC. And output. Also in this case, the change in the DC voltage due to the change in the output power of the inverse converter does not immediately appear.

However, according to the configuration of the present invention, the power command value or the power deviation is added as a factor for determining the control output to the DC voltage control system which originally operates according to the voltage deviation, so that the inverse converter is used. The change in the power command is immediately reflected in the voltage control of the forward converter, and active current control for voltage control is executed. Since the active current control is configured to have a high response, a current according to the power command value or the power deviation is injected from the forward converter into the DC circuit, and the voltage fluctuation of the DC circuit is suppressed. As a result, fluctuations in power are also suppressed, and high-speed power control can be realized.

Further, according to the configuration of the present invention, since the unit control device for controlling the power converter has the same configuration with both the voltage control function and the power control function being selectable, the power flow direction command Enables a flexible system configuration that can handle any combination of when the sharing of the forward converter and the inverse converter is reversed, or when the sharing of the voltage control and power control of the two power converters is changed. It is suitable for power interchange.

[0021]

Embodiments of the present invention will now be described in detail with reference to the drawings. The same reference numerals denote the same functions throughout the drawings.

FIG. 1 shows an embodiment of a control device for a self-excited DC power transmission facility. Self-excited DC transmission equipment is AC system 1
1, 12, conversion transformers 21 and 22, self-extinguishing element (G
TO) voltage type self-excited converters 31, 3
2. A DC capacitor 40 and DC power transmission lines 51 and 52. The DC circuit includes a DC capacitor 40 and DC power transmission lines 41 and 42, but may not have a long-distance power transmission line such as power interchange.

The control device for the DC power transmission equipment of this embodiment comprises operation command device 300 and converter control devices 310, 320 for controlling each of the self-excited converters 31, 32.

The converter control device 310 includes an AC voltage transformer 311 for detecting the voltage at the AC / DC interconnection point, an AC current transformer 312 for detecting the current of the self-excited converter 31 flowing in the AC system 11, and an AC voltage transformer. 331 and AC current transformer 31
The detection values of the power detection circuit 313 that detects the active / reactive power of the self-exciting converter 31 and the detection value of the DC voltage transformer 315 that detects the voltage of the DC circuit are taken in from the detection value of 2.

Similarly, in the converter control device 320, an AC voltage transformer 321 for detecting the voltage at the AC / DC interconnection point, an AC current transformer 322 for detecting the current of the self-excited converter 32 flowing in the AC system 12, Based on the detected value of the AC voltage transformer and the detected value of the AC current transformer, the detected value of the power detection circuit 323 that detects the active / reactive power of the self-excited converter 32 and the detected value of the DC voltage transformer 315 that detects the voltage of the DC circuit are It is captured.

Generally, the DC power transmission equipment is composed of AC systems 11 and 1
Since there is a need for power interchange between the two, it is necessary that the power flow can be reversed, and there is a case where one converter can be configured to operate both the forward converter and the inverse converter. Many.

FIG. 2 is a diagram for explaining the general function of the DC power transmission equipment, and shows the relationship between the electric power and the current before and after the power flow inversion. In the same figure (a), the converter 32 operated in reverse conversion is operated.
Is designated as P ₂ , and the voltage of the power capacitor 40 is Vd. In the steady state of the converter 32, the current i ₂ (= P ₂ / V) necessary for sending the electric power P ₂ to the AC system 2
d) flows from the condenser 40 in the direction shown.

On the other hand, in the converter 31 which performs the forward conversion operation,
In order to prevent the DC voltage from decreasing due to the outflow of the current i ₂ , the current i ₁ flows from the AC system 1 in the direction shown in the drawing to keep the DC voltage constant. Ignoring the circuit loss, i ₁ = i ₂ is constantly maintained, and the decrease in the DC voltage Vd disappears.
The equilibrium state of (Equation 3) is reached.

[0029]

Equation 3] _{P 1 = Vd · i 1 =} Vd · i 2 = P 2 FIG. 2 (b) is a case of transmitting the power from tidal currents inverted AC system 2 to the AC system 1. The converter 31 is in reverse conversion operation, and the converter 32 is in forward conversion operation. When the transmitted power is designated as P ₁ , a current of i ₁ flows from the capacitor 40 to the converter 31 in the direction shown in the figure in a steady state, and the converter 32 is switched from the AC system 2 in order to prevent the DC voltage from being lowered. The current i ₂ is applied to the capacitor 40. Ignoring the circuit loss, i ₁ = i ₂ is constantly maintained, and the DC voltage Vd does not drop. In this case as well, the equilibrium state of (Equation 3) is obtained.

As described above, even if the direction of electric power in the DC power transmission equipment is changed, bidirectional power transmission can be performed by providing the forward converter and the inverse converter with the same control function. In the control device of this embodiment, the converter 31 is a forward converter,
The converter control devices 310 and 320 having basically the same configuration are provided in both cases of operating the converter 32 as an inverse converter and vice versa.

In FIG. 3, one converter controller 310 (3
The detailed configuration of 20) is shown by functional blocks. The power control circuit 3101 (3201) receives the power command value Pp from the operation command device 300 and the active power detection value Pf from the power detection circuit 313 (323), and sets the power deviation ΔP to 0.
And outputs the active current command value Idp ₁ .

The voltage control circuit 3102 (3202) controls the DC voltage command value Vp of the DC circuit from the operation command device 300.
And the DC voltage detection value Vf from the DC voltage transformer 315, the voltage deviation ΔV is calculated, and the active current command value Idp ₂
Is output.

FIG. 4 shows a power control circuit 3101 (320).
1) and the configuration of the voltage control circuit 3102 (3202) are shown. The former, a first adder AD1 to obtain the deviation of the power command value Pp and active power detected value Pf, composed of the first operational amplifier AM1 for outputting a command value Idp ₁ by amplifying the deviation. The latter is a second adder AD2 for obtaining the deviation between the DC voltage command value Vp and the DC voltage detection value Vf, and a command value Idp ₂ by adding the outputs of the second operational amplifiers AM2, AM1 and AM2 for amplifying this deviation. Third adder AD3 for outputting
Composed of.

The switch circuit 3103 (3203) receives the flow direction command COM from the operation command device 300,
Either Idp ₁ or Idp ₂ is selected as the output Idp. The tidal current direction command COM is the converter 31 to be controlled.
(32) is an instruction that specifies whether to operate as a forward converter or an inverse converter.

Effective current control circuit 3104 (3204)
Is the effective component current (actual current) of the self-exciting converter 31 (32)
The component is controlled to the command value Idp. Reactive power control circuit 31
05 (3205) receives the reactive power command value Qp from the operation command device 300 and the reactive power detection value Qf from the power detection circuit 313 (323) and calculates the reactive power deviation ΔQ to obtain the reactive current command value Iqp. Output. The reactive current control circuit 3106 (3206) controls the reactive current (imaginary current) component of the self-exciting converter 31 (32) to the command value Iqp.
The 2-phase / 3-phase conversion circuit 3107 (3207) performs dq inverse conversion and αβ inverse conversion on the outputs of the active component current control circuit 3104 (3204) and the reactive component current control circuit 3106 (3206), and then performs the 3-phase conversion. The two-phase / three-phase conversion circuit, PWM control circuit 3108 (3208) outputs a control pulse for controlling the self-excited converter 31 (32) from the three-phase converted control signal.

The method of controlling the active component current (real current) and the reactive component current (imaginary current) by the dq two-axis conversion in the self-exciting converter is a stable power conversion method with a quick response and is disclosed in the above-mentioned Japanese Patent Application Laid-Open No. Hei. It is disclosed in detail in No. 367011. As illustrated in FIG. 1 of the same example, the active component current control circuit and the reactive component current control circuit separate the active component and the reactive component of the actually measured alternating current together with the command value and use them as inputs. Although the same configuration is used in this embodiment, the configuration shown in FIG.
The active component current control circuit 3104 (3204) and the reactive component current control circuit 3106 (3206) are described in abbreviated form for the sake of simplicity.

Next, the operation of the control device for the DC power transmission equipment configured as described above will be described. In DC power transmission, it is general to control the power of the power receiving AC system to a required value (command value). In this case, the forward converter controls the DC voltage and the inverse converter controls the transmission power. In the following, it is assumed that the converter 31 operates as a forward converter and the converter 32 operates as an inverse converter.

Power flow direction command C from the operation command device 300
The OM corresponds to the operation mode of the converters 31 and 32, is given to the converter control devices 310 and 320, and switches its switch circuits 3103 and 3203. Controller 310
Then, the output Idp ₂ of the voltage control circuit 3102 is selected to perform the constant voltage control operation of the forward converter. On the other hand, the control device 3
At 20, the output Idp ₁ of the power control circuit 3201 is selected and the power control operation of the inverse converter is performed.

Here, it is assumed that the power command value Pp is changed. In the control device 320, since the power command value Pp of the power control circuit 3201 changes, a deviation appears in the first adder AD1, and the active component current command value Idp ₁ is changed.
When Idp ₁ changes, a fast response active current control circuit 32
04 operates to change the effective component current (actual current) flowing through the inverse converter 32, and controls the transmitted power to the power command value Pp.

On the other hand, in the control device 310, the power command value P
Even if p changes and the effective current of the inverse converter 32 changes, the DC voltage of the DC circuit does not immediately change, and the voltage control circuit 3
No deviation appears in the second adder AD2 of 102. However, since Idp ₁ of the power control circuit 3101 has changed, the output of the voltage control circuit 3102 changes. When Idp ₂ changes, the active component current control circuit 3104 operates to change the active component current flowing through the forward converter 31, thereby suppressing the voltage change of the DC circuit.

When the active power detection value becomes a value equal to the command value by the power control of the inverse converter 32, the power deviation becomes 0 and Idp ₂ does not change, and the power command value Pp.
The voltage control that accompanies the change of is established.

In the conventional voltage control, the forward converter does not operate immediately even if the active power of the inverse converter changes. Only when the DC voltage of the DC circuit changes, the effective component current command value Idp ₂ appears, and the control of the forward converter is started. Thus, after the delay on the main circuit and the delay on the control circuit due to the long-distance transmission line, the charging current from the forward converter to the DC capacitor was flowing.

However, in this embodiment, the active component current command value of the forward converter is immediately changed by adding the output of the power control circuit to the output of the voltage control circuit. A current flows in, and the change in DC voltage can be suppressed at high speed. As a result, the transmission power of the self-excited DC transmission facility can be controlled at high speed and stably.

Next, a second embodiment of the present invention will be described.
FIG. 5 shows the configuration of the power control circuit and the voltage control circuit of the converter control device. In the figure, the divider DEV is added to the configuration of FIG.
And a fourth adder AD4 is added.

The divider DEV receives the power command value Pp from the operation command device 300, and divides this Pp by another input voltage detected value Vf. Fourth adder A
D4 adds the divided signal to the output of the first operational amplifier AM1 and outputs the command value Idp ₁ . As in the case of FIG. 4, the command value Idp ₁ is added to the output of AM ₂ by the third adder AD 3 to become the command value Idp ₂ .

According to this structure, a change in the power command value Pp or the DC voltage Vd immediately changes the output Idp ₁ of the power control circuit 3101. Therefore, the DC voltage control and the power control response are different from those in the structure of FIG. Can be further increased.

Next, a third embodiment of the present invention will be described.
FIG. 6 shows the configuration of the voltage control circuit of the converter control device.

In the figure, a divider DEV is added to the voltage control circuit 3102 of FIG. 4, the power command value Pp from the operation command device 300 is input, and this Pp is used as the DC voltage detection value Vf.
The value obtained by dividing by is added by the third adder AD3 to obtain the command value Idp ₂ .

That is, instead of the command value of the power control circuit 3101, a value corresponding to the power command value Pp from the operation command device 300 is added to the command value of the voltage control circuit 3102, and the DC voltage control The response speed has been improved.

According to this, since the output from the power control means is not required, it is not necessary to transmit the power control command value Idp ₁ or the active power detection value Pf from the inverse converter side to the forward converter side. Even when the power transmission line has a long distance, a control delay due to a signal transmission delay does not occur.

In the above-described first to third embodiments, the case where the forward converter controls the voltage and the inverse converter controls the power has been described, but the present invention is not limited to this. That is, even when power control is performed by the forward converter and voltage control is performed by the inverse converter, the control operations of the forward converter and the inverse converter are only opposite to the above.
Therefore, the power flow direction command COM from the operation command device 300
The present invention can be applied in the same manner as described above by simply reversing the switching of the switch circuits 3103 and 3203 by the above, and the transmission power of the self-excited DC power transmission equipment can be controlled at high speed and stably.

Next, another application example of the present invention will be described. In the above-described embodiment, the DC power transmission equipment that can transmit power in both directions by the power flow reversal is applied. However, the present invention can also be applied to DC power transmission equipment for one-way power transmission that does not perform power flow inversion.

For example, it is assumed that the converters 31 and 32 shown in FIG. 1 have the functions of a forward converter and an inverse converter, respectively. In this case, the control device 310 shares the voltage control and the control device 320 shares the power control, so that each can be dedicated.

FIG. 7 shows the configuration of a controller dedicated to the forward converter in the fourth embodiment. Comparing this figure with the control device of FIGS. 4 and 5, the power control circuit 3101 and the switch circuit 3103 are omitted. Third adder AD
The command value Idp ₁ input to 3 is transmitted from the control device 320 of the inverse converter 32. A power control circuit 3201 that outputs the command value Idp ₁ is provided on the control device 320 side (not shown), and the voltage control circuit 3202 is omitted.

As described above, in the case of one-way power transmission, the voltage control circuit is provided on the forward converter side and the power control circuit is provided on the inverse converter side, and the command value of the power control circuit is added to add the command of the voltage control circuit. By setting the value, the response speed of the DC voltage control and the power control can be increased as in the case of the above embodiment.

In the case of this configuration, there is a signal transmission delay from the inverse converter side to the forward converter side, but the transmission delay is not a problem when there is no DC transmission line or when it is short. The third embodiment shown in FIG. 6 may be applied as a voltage control circuit of a unidirectional power transmission forward converter. According to this, there is no delay even in the case of long-distance power transmission, and the response speed of DC voltage control and power control can be increased.

Dedicated control devices for the above-described one-way power transmission are also applicable to the case where the control mode (voltage control / power control) of the converter is fixed regardless of the operation mode (forward conversion / reverse conversion). Applicable.

[0058]

According to the present invention, since the change of the power command to the inverse converter is immediately reflected in the voltage control of the forward converter, there is an effect that the constant voltage control and the power control of the DC power transmission equipment can be speeded up. .

Further, according to the present invention, since the unit control device for controlling the power converter has the same configuration in which both functions of the voltage control and the power control can be arbitrarily selected, the operation mode and the control mode can be selected. This has the effect of realizing a flexible system configuration that can support any combination.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a control device for a self-excited DC power transmission facility according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating a function of DC power transmission equipment.

FIG. 3 is a configuration diagram of a control device according to the first embodiment.

FIG. 4 is a configuration diagram showing details of a power control unit and a voltage control unit in FIG.

FIG. 5 is a configuration diagram of a control device according to a second embodiment of the present invention.

FIG. 6 is a configuration diagram of a control device according to a third embodiment of the present invention.

FIG. 7 is a configuration diagram of a control device of a fourth embodiment in which the present invention is applied to one-way power transmission.

[Explanation of symbols]

11, 12 ... AC system, 21, 22 ... Transformer for conversion, 3
1, 32 ... Self-exciting converter, 40 ... DC capacitor, 4
1, 42 ... DC power transmission line, 300 ... Operation command device, 31
0,320 ... Control device, 311, 321 ... AC voltage transformer, 312, 322 ... AC current transformer, 313, 323
... Power detection circuit, 315 ... DC voltage transformer, 3101 ...
Power control circuit, 3102 ... Voltage control circuit, 3103 ... Switch circuit, 3104 ... Active component current (actual current) control circuit, 3105 ... Reactive power control circuit, 3106 ... Reactive component current (imaginary current) control circuit, 3107 ... Two-phase / 3 phase conversion circuit, 3108 ... PWM control circuit, AD1 ... first adder, AD2 ... second adder, AD3 ... third adder, A
D4 ... Fourth adder, AM1 ... First operational amplifier, AM
2 ... 2nd operational amplifier, DEV ... Divider, Idp1 ... Output of power control circuit, Idp2 ... Output of voltage control circuit, COM
... power flow direction command, Idp ... active current (actual current) command value, Pp ... power command value, Pf ... power detection value, Vp ... DC voltage command value, Vf ... DC voltage detection value, Qp ... reactive power command value, Qf ... Reactive power detection value, Iqp ... Reactive current (imaginary current) command value.

Claims (12)

[Claims] 1. A power transmission side converts alternating current into direct current, and a power receiving side converts direct current into alternating current through a direct current circuit, and one side of the power transmitting side or the power receiving side controls the direct current voltage of the direct current circuit to be constant. In the control method of the self-excited DC power transmission equipment that controls the transmission power on the other side according to the command value, the voltage command value of the DC voltage and the voltage deviation due to the voltage measurement value, the power command value of the transmission power or the command value And a control output of the DC voltage based on a power deviation based on an actual power measurement value. 2. The method according to claim 1, wherein when the power transmitting side and the power receiving side are reversed by a power flow direction command, the control side of the DC voltage and the control side of the transmitted power are switched according to the command. Control method for self-excited DC power transmission equipment. 3. The control output of the DC voltage according to claim 1 or 2, based on an added value of a value according to the voltage deviation and a value according to division of the power command value and the voltage actual measurement value. A method for controlling a self-excited DC power transmission facility, which is characterized in that 4. The control output of the DC voltage according to claim 1, wherein the control output of the DC voltage corresponds to a value according to the voltage deviation and a control output of transmission power executed on the other side based on the power deviation. A method for controlling a self-excited DC power transmission facility, which is characterized in that it is obtained based on a value added to the value. 5. The method of controlling a self-excited DC power transmission facility according to claim 4, wherein the added value includes a value corresponding to a division of the power command value and the voltage actual measurement value. 6. The control output of the DC voltage or the control output of the transmission power corresponds to the control of the effective portion of the current actually measured on the power transmission side or the power reception side according to any one of claims 1 to 5. A method for controlling a self-excited DC power transmission facility, comprising: 7. A first self-exciting converter for converting alternating current into direct current on the power transmission side, and a direct current circuit including a power capacitor.
In a control device for a self-excited DC power transmission facility including a second self-excited converter that reversely converts direct current to alternating current on the power receiving side, in order to set the power transmitted on the power receiving side to the power command value,
Power control means for controlling the second self-excited converter based on a power control output corresponding to the power deviation between the power command value and the measured value thereof, and a constant DC voltage of the DC circuit, Voltage control means for controlling the first self-exciting converter based on a DC voltage command value of the DC circuit and a voltage deviation based on a measured value of the DC voltage and the power command value or the power deviation. A control device for a self-excited DC power transmission facility, comprising: 8. A control device for a self-excited DC power transmission facility, comprising a forward converter for converting AC to DC on the power transmitting side, a DC circuit including a power capacitor, and an inverse converter for converting DC to AC on the power receiving side. In the operation command device for outputting the transmission power command value of the inverse converter and the DC voltage command value of the forward converter, and the power command so that the transmission power of the inverse converter is the same as the power command value. A power control means for controlling the inverse converter based on a power control output according to a power deviation between the value and its measured value, and the DC voltage command value and the DC voltage command value so that the DC voltage of the DC circuit is constant. Self-excited DC power transmission, comprising: voltage control means for controlling the forward converter based on a voltage control output obtained by adding a value according to a voltage deviation based on an actual measurement value and a value according to the power command value. Equipment control device. 9. The control device for self-excited DC power transmission equipment according to claim 8, wherein the added value is configured to be provided with the power control output from the power control means. 10. Two self-excited converters capable of converting power from AC to DC or from DC to AC in both directions.
In a control device of a DC power transmission facility that includes a DC circuit including a power capacitor that connects converters of one unit, and controls the power of one of the converters and the voltage of the other, a transmission power command value, a DC voltage command value, and a power flow An operation command device that outputs a directional command value, and for each of the self-exciting converters, a power control unit that controls the transmitted power according to the command value according to the power deviation between the command value of the transmitted power and the measured value thereof, the direct current Voltage control means for controlling the DC voltage of the DC circuit to be constant based on the voltage deviation between the voltage command value and its measured value, and one output of the power control means or the voltage control means is selected according to the power flow direction command. And a unit control device having a switch means for controlling the direct current power transmission equipment. 11. The switching means of the unit control device according to claim 10, wherein one of the self-exciting converters is operated as a forward converter and the other is operated as an inverse converter in response to the flow direction command. A control device for a self-excited DC power transmission facility, characterized in that the output of the voltage control means is selected on the converter side and the output of the power control means is selected on the inverse converter side. 12. The voltage control means according to claim 10, further comprising an addition means for adding a value according to the voltage deviation and the power command value or a value according to the power deviation. A characteristic control device for self-excited DC power transmission equipment.