JP2004266915A - Method for controlling voltage of power transmission and distribution system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for controlling the voltage of a power transmission and distribution system which can compensate for a voltage change while an SVR or an OLTC and an existing voltage constant control type SVC are cooperated merely by additionally installing a simple unit at the outside. <P>SOLUTION: The method for controlling the voltage of the power transmission and distribution system includes a step of compensating the voltage change of the power transmission and distribution system by installing the SVR or the OLTC and a voltage constant control type SVC in the power transmission and distribution system. The method further includes the steps of further installing a voltage signal detection processing unit for detecting and processing the voltage change of the power transmission and distribution system in the power transmission and distribution system, and operating the SVC based on the output signal of this voltage signal detecting and processing unit. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a voltage control method for a power transmission and distribution system, and in particular, installs a high-speed device such as a static var compensator (hereinafter abbreviated as SVC) in the power transmission and distribution system and controls the power transmission and distribution system. The present invention relates to a voltage control method for stabilizing the voltage of the power transmission and distribution system by supplying reactive power for detecting a voltage fluctuation and instantaneously canceling a load fluctuation amount.
[0002]
[Prior art]
In recent years, the need for improving the quality of electric power has been increasing due to the progress of the advanced information society. However, due to the effects of wind power generation equipment linked to the transmission and distribution system and large-capacity motor loads, the conventional step-type power regulator (Step In some cases, a transient voltage fluctuation that cannot be compensated for by using a voltage regulator (hereinafter abbreviated as SVR) or a tap change device under load (hereinafter abbreviated as OLTC) occurs. Therefore, a voltage control method that incorporates a constant voltage control type SVC into a power transmission and distribution system and utilizes its high-speed response has been implemented.
[0003]
However, when the constant voltage type SVC and the SVR (for the power distribution system) or the OLTC (for the power transmission system) are installed in the same power transmission and distribution system, the slow voltage fluctuation to be compensated by the SVR or the OLTC is not affected by the SVC. Compensation is first performed for high-speed responsiveness, and a problem arises in that it is not possible to secure a high-speed voltage fluctuation compensation capacity that should be originally handled by the SVC. FIG. 1 is a graph showing an example of voltage compensation in SVC for explaining such a problem. For example, when a voltage fluctuation in which a slow fluctuation and a high-speed fluctuation are superimposed as shown in FIG. 1A occurs, the operation is such that all voltage fluctuations are compensated only by the SVC and the voltage compensation as shown in FIG. Is performed, and a portion exceeding the compensation capacity of the SVC remains as an uncompensated portion as shown in FIG. 1c.
[0004]
In order to solve this problem, various methods in which SVC is mainly improved have been proposed and put into practical use. For example, "Development of SVR cooperative operation type SVC" by Furukawa and Yoshitake, National Institute of Electrical Engineers of Japan, 1593, March 1998. In the conventional conventional constant voltage control type SVC main body, in addition to the SVC original voltage constant control unit, a reactive power detection unit, a reactive power output target range command unit, and a calculation unit are provided. The aim is to enable cooperative operation with SVC or OLTC by limiting the compensation function. By limiting the voltage compensating function of the conventional voltage-constant control type SVC, the voltage change that the SVC could not compensate is SVR or OLTC if it has a speed that can be compensated by SVR or OLTC. The OLTC takes charge of compensation, and voltage control of the power transmission and distribution system can be performed in cooperation with the SVC. However, this method has a disadvantage that the existing constant voltage control type SVC cannot be used as it is, and it is necessary to replace it with a modified SVC.
[0005]
High-speed devices other than SVC, that is, voltage control devices that respond in seconds or about 10 seconds or less, for example, SVG (Static Var Generator) also called self-excited SVC, UPFC (Unified Power Flow Controller), phase shifter, or stationary phase Power devices that apply power electronics generally called FACTS devices, such as a phase shifter (PS) also called a regulator and a Thyristor Controlled Series Capacitor (TCSC) also called a static series capacitor, operate in cooperation with an SVR or an OLTC. It can be used for control. In this case, the same problem as that of the SVC described above occurs. At present, distributed power sources other than electric power companies are increasing due to the liberalization of electric power, and it is not decided how to perform voltage control for these power sources. High-speed voltage control is possible, and can be used for voltage control in cooperation with SVR or OLTC. In this case as well, there is a limit in the adjustment capacity of the distributed power supply, so that the same problem as in the SVC described above occurs. In addition, there is a problem that, even in an existing large-capacity power plant, if voltage control is performed, the output of electric power (active power) must be limited as a price. At present, this problem is not particularly apparent, but there is a possibility that the adjustment capacity will be limited by the liberalization of power in the future, and in this case, the same problem as the above-described SVC will occur.
[0006]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the conventional power transmission and distribution system voltage fluctuation compensation method as described above, and to provide an SVR or OLTC and an existing high-speed device of a constant voltage control method by simply adding a simple device externally. In particular, it is an object of the present invention to provide a voltage control method for a power distribution system and a voltage control method for a power transmission system that can compensate for voltage fluctuations while cooperating with an SVC.
[0007]
[Means for Solving the Problems]
A voltage control method for a distribution system according to the present invention includes a step-type voltage regulator and a static var compensator of a constant voltage control system installed in the distribution system to compensate for voltage fluctuations in the distribution system. In the control method, a voltage signal detection processing device that detects and processes voltage fluctuation of the distribution system is further installed in the power distribution system, and the static var compensator is configured based on an output signal of the voltage signal detection processing device. It is characterized by operating. In this way, by adding a simple voltage signal detection processing device and simple setting and adjustment thereof, efficient voltage fluctuation compensation control of the power distribution system by cooperative operation between the SVR and the SVC becomes possible.
[0008]
In one embodiment of the voltage control method for a power distribution system according to the present invention, the voltage signal detection processing device includes a high-pass filter, a low-pass filter, a limiter, and a superposition circuit. . This makes it possible to easily realize the voltage signal detection processing device.
[0009]
Another embodiment of the voltage control method of the distribution system according to the present invention is characterized in that the ratio between the high-speed response and the low-speed response of the static var compensator is arbitrarily set according to the setting level of the limiter. With this configuration, it is possible to efficiently control the voltage fluctuation of the power distribution system by cooperative operation of the SVR and the SVC with a simple setting according to the required voltage stability of the voltage controlled device, the voltage fluctuation level of the power distribution system, and the like. become.
[0010]
A voltage control method for a power transmission system according to the present invention includes a voltage control method for a power transmission system in which a tap change device at load and a static var compensator of a constant voltage control method are installed in the power transmission system to compensate for voltage fluctuations in the power transmission system. In the method, a voltage signal detection processing device for detecting and processing voltage fluctuation of the transmission system is further installed in the power transmission system, and the static var compensator is operated based on an output of the voltage signal detection processing device. It is characterized by the following. With this configuration, by adding a simple voltage signal detection processing device and simple setting and adjustment thereof, efficient voltage fluctuation compensation control of the power transmission system by cooperative operation between the OLTC and the SVC can be performed.
[0011]
One embodiment of a voltage control method for a power transmission system according to the present invention is characterized in that the voltage signal detection processing device includes a high-pass filter, a low-pass filter, a limiter, and a superposition circuit. . This makes it possible to easily realize the voltage signal detection processing device.
[0012]
Another embodiment of the voltage control method of the transmission system according to the present invention is characterized in that the ratio of the high-speed response and the low-speed response of the static var compensator is arbitrarily set according to the set level of the limiter. This makes it possible to perform efficient voltage fluctuation compensation control of the power transmission system by cooperative operation of the OLTC and the SVC with simple settings according to the required voltage stability of the voltage control target device, the voltage fluctuation level of the power transmission system, and the like. become.
[0013]
In the voltage control method of the power transmission system and the voltage control method of the power distribution system according to the present invention as described above, a high-speed device of another constant voltage control method is used instead of the static var compensator of the constant voltage control method, that is, the SVC. However, the present invention can be implemented with a similar configuration, and a similar effect can be obtained.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
A voltage control method for a transmission and distribution system according to the present invention includes installing an SVR (for a distribution system) or an OLTC (for a transmission system) and a constant voltage control type SVC in a transmission and distribution system, further including a high-pass filter and a low-pass filter. A voltage signal detection processor comprising a band-pass filter, a limiter, and a superimposing circuit is installed, and the high-pass filter is provided according to a required voltage stability of a supply voltage target device, a voltage fluctuation level of a transmission and distribution system, and the like. , A low-pass filter and a limiter are set, and the SVC is operated based on an output signal from the voltage signal detection processing device.
[0015]
FIG. 2 is a block diagram showing a basic configuration of a voltage signal detection processing device used in the voltage control method of the power transmission and distribution system according to the present invention. The voltage signal detection processing device 1 includes a high-pass filter 2 and a low-pass filter 4 arranged to receive an input signal, a limiter 6 arranged to receive an output signal of the high-pass filter 2, A superposition circuit 8 arranged to receive the output signal of the bandpass filter 4 and the limiter 6.
[0016]
FIG. 3 is a graph showing an example of a signal in each of the parts a to e shown in FIG. The horizontal axis in each graph indicates time, and the vertical axis indicates voltage. FIG. 3a shows the signal in part a of FIG. This signal is a bus voltage signal to be controlled, and includes a high-frequency fluctuation and a low-frequency fluctuation, and the fluctuation range is larger than the voltage compensation range in the SVC. This signal is an input signal to the voltage signal detection processing device 1 and is input to the high-pass filter 2 and the low-pass filter 4 in the voltage signal detection processing device 1. FIG. 3B shows a signal in a portion b of FIG. 2, which is an output signal of the low-pass filter 4 and is input to the limiter 6. FIG. 3C shows a signal in a part c of FIG. 2, which is an output signal of the limiter 6 and is input to the superimposing circuit 8. FIG. 3D shows a signal in a part d in FIG. 2, which is an output signal of the high-pass filter 2 and is input to the superposition circuit 8. FIG. 3e shows the signal at the part e in FIG. 2, which is the output signal of the superposition circuit 8 and the output signal of the voltage signal detection processing device 1, and is supplied to the SVC (not shown). Here, the filter coefficients of the high-pass filter 2 and the low-pass filter 4 and the limiter range of the limiter 6 are set so that the fluctuation range of the signal in the section e falls within the voltage compensation range of the SVC. With this configuration, all the voltage fluctuations of the signal in the portion e are compensated by the SVC. FIG. 4 is a graph showing low frequency fluctuations that cannot be compensated for by the SVC. This low frequency fluctuation is compensated by SVR or OLTC. In order to compensate for the low-frequency component in a distribution system in which a power source is installed on the secondary side (end side of the distribution line) of the SVR, it is necessary to take measures such as removing a reverse flow prevention relay. , SVR are known and will not be described in detail here. The voltage compensation procedure is also known for the OLTC and will not be described in detail here. As described above, the SVC operates under appropriate conditions by adjusting the setting range of the limiter 6 in FIG. 3 according to the voltage compensable range (that is, the SVC capacity) of the SVC installed in the power transmission and distribution system. It becomes possible to do. Incidentally, when the setting range of the limiter is set to zero, the operation is performed in a state where the SVC capacity is minimum (in the SVC, only the high-frequency voltage fluctuation is compensated and all the low-frequency voltage fluctuations are compensated in the SVR or OLTC).
[0017]
The above description relates to a method of providing a satisfactory variable voltage compensation function by additionally installing a voltage signal detection processing device of the present invention when a constant voltage control type SVC and SVR or OLTC are already installed in a transmission and distribution system. As an explanation, when a voltage constant control type SVC and a voltage signal detection processing device of the present invention are additionally installed in a transmission and distribution system in which only an SVR or an OLTC is installed to stabilize the voltage, the SVC capacity is required. By appropriately adjusting the limiter and the limiter range, a function of compensating a fluctuating voltage can be flexibly realized in correspondence with SVCs of various capacities.
[0018]
FIG. 5 is a graph showing a load curve of the power distribution system. The horizontal axis represents time, and the vertical axis represents voltage. FIG. 6 is a graph showing a disturbance component added to the load curve of FIG. 5, in which the horizontal axis represents time and the vertical axis represents voltage. Simulation analysis was performed for each of the following three cases.
Case 1: Voltage fluctuation compensation control using only SVR Case 2: Cooperative operation control of SVR and constant voltage control type SVC Case 3: Cooperative operation control analysis conditions of SVR and SVC by the method of the present invention (distribution system setting conditions) Are not shown because they are not essential for describing the present invention.
[0019]
FIG. 7 is a graph showing the controlled bus voltage (voltage waveform after performing the voltage fluctuation compensation control) in Case 1. The horizontal axis represents time, and the vertical axis represents voltage. From this graph, it can be seen that the SVR alone cannot provide sufficient compensation and has a waveform in which the low-frequency fluctuation component and the high-frequency fluctuation component overlap.
[0020]
FIG. 8A is a graph showing the controlled bus voltage in Case 2. The horizontal axis represents time, and the vertical axis represents voltage. From this graph, it can be seen that the overall voltage fluctuation is improved as compared to the case of only the SVR control in case 1 shown in FIG. 7, but it is clear that the high-frequency fluctuation component is not compensated over the entire time period. Understand. FIG. 8B is a graph showing the control amount of the SVC at this time. The horizontal axis represents time, and the vertical axis represents voltage. From this graph, it can be seen that the region beyond the controllable range of the SVC has a linear waveform, and the high-frequency fluctuation component remains uncompensated in the portion of FIG. 8A corresponding to this region.
[0021]
FIG. 9A is a graph showing the controlled bus voltage in Case 3. The horizontal axis represents time, and the vertical axis represents voltage. From this graph, it can be seen that the voltage fluctuation is improved as compared with the conventional SVR and SVC cooperative operation control of Case 2 shown in FIG. 8A, and the high-frequency fluctuation component is also compensated over the entire time period. FIG. 9B is a graph showing the control amount of the SVC at this time. The horizontal axis represents time, and the vertical axis represents voltage. From this graph, it can be understood that the control is performed without exceeding the controllable range of the SVC by the cooperation method of the present invention.
[0022]
Although the above description has been given of an example of voltage control of the distribution system (cooperation between SVC and SVR), the same effect can be obtained with respect to voltage control of the transmission system (cooperation between SVC and OLTC). . In addition, instead of the SVC, a high-speed voltage control device to which power electronics such as SVG, UPFC, PS, and TCSC are applied, or a distributed power supply, a generator, or the like can be used. The effect can be obtained.
[Brief description of the drawings]
FIG. 1 is a graph showing an example of voltage compensation in SVC.
FIG. 2 is a block diagram showing a basic configuration of a voltage signal detection processing device according to the present invention.
FIGS. 3A to 3E are graphs showing examples of signals in respective units a to e shown in FIG. 2;
FIG. 4 is a graph showing a low-frequency variation that cannot be completely compensated by SVC.
FIG. 5 is a graph showing a load curve of a power distribution system.
FIG. 6 is a graph showing a disturbance component added to the load curve of FIG. 5;
FIG. 7 is a graph showing a controlled bus voltage in case 1;
8A is a graph showing a controlled bus voltage in Case 2, and FIG. 8B is a graph showing a control amount of SVC.
9A is a graph showing a controlled bus voltage in Case 3, and FIG. 9B is a graph showing an SVC control amount.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Voltage signal detection processing device 2 High-pass filter 4 Low-pass filter 6 Limiter 8 Superposition circuit

Claims (12)

A voltage control method for a distribution system in which a step-type voltage regulator and a high-speed device of a constant voltage control method are installed in a distribution system to compensate for the voltage variation of the distribution system, A voltage control method for a power distribution system, further comprising: installing a voltage signal detection processing device that detects and processes the voltage, and operating the high-speed device based on an output signal of the voltage signal detection processing device. The voltage control method for a power distribution system according to claim 1, wherein the voltage signal detection processing device includes a high-pass filter, a low-pass filter, a limiter, and a superposition circuit. Distribution system voltage control method. 3. The voltage control method for a distribution system according to claim 1, wherein a ratio between a high-speed response and a low-speed response of the high-speed device is arbitrarily set according to a setting level of the limiter. 4. . A voltage control method for a distribution system, in which a step-type voltage regulator and a static var compensator of a constant voltage control method are installed in a distribution system to compensate for voltage fluctuations in the distribution system, the method comprises the steps of: A voltage signal detection processing device for detecting and processing voltage fluctuations in the system is further installed, and the static type reactive power compensator is operated based on an output signal of the voltage signal detection processing device. Voltage control method. 5. The voltage control method for a distribution system according to claim 4, wherein the voltage signal detection processing device includes a high-pass filter, a low-pass filter, a limiter, and a superposition circuit. Distribution system voltage control method. 5. The distribution system voltage control method according to claim 3, wherein a ratio between a high-speed response and a low-speed response of the static var compensator is arbitrarily set according to a setting level of the limiter. 6. Voltage control method. In a voltage control method of a transmission system, in which a load tap switching device and a high-speed device of a constant voltage control method are installed in a transmission system to compensate for a voltage variation of the transmission system, the voltage variation of the transmission system is reduced during the transmission system. A voltage compensation method for a power transmission system, further comprising installing a voltage signal detection processing device for detecting and processing, and operating the high-speed device based on an output of the voltage signal detection processing device. The voltage control method for a power transmission system according to claim 7, wherein the voltage signal detection processing device includes a high-pass filter, a low-pass filter, a limiter, and a superposition circuit. Voltage control method for transmission system. 9. The voltage control method for a power transmission system according to claim 7, wherein a ratio between a high-speed response and a low-speed response of the high-speed device is arbitrarily set according to a setting level of the limiter. . In a voltage control method for a transmission system, in which a tap change device under load and a static var compensator of a constant voltage control method are installed in a transmission system to compensate for voltage fluctuations in the transmission system, the transmission system includes A voltage signal detection processor for detecting and processing the voltage fluctuation of the power system, and operating the static var compensator based on the output of the voltage signal detection processor. Method. The voltage control method for a power transmission system according to claim 10, wherein the voltage signal detection processing device includes a high-pass filter, a low-pass filter, a limiter, and a superposition circuit. Voltage control method for transmission system. 12. The power transmission system voltage control method according to claim 10, wherein a ratio between a high-speed response and a low-speed response of the static var compensator is arbitrarily set according to a setting level of the limiter. Voltage control method.

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