JPH0879973A - Power system control device - Google Patents

Abstract

PURPOSE: To suppress the oscillation of a power system when a demand balance is lost and at the same time readily throw a generation facility which is released from the system into the power system again. CONSTITUTION: A generation facility for supplying power and a substation for consuming the power are connected to a power transmission system 6 and data including the connection state between the generation facilities and the power/voltage/breaker of the substation are transmitted to a central controller 2 via a data communication line 7. A system condition operation device 3 installed at the central controller 2 transmits a frequency instruction value F, a voltage phase 6 for each generation facility, and a reference time t outputted by a reference clock 5 to each generation facility via an instruction value communication line 8. Each generation facility determines a frequency setting value and a generation power instruction value based on them. The generation facility thrown into the system calculates a voltage phase when it is being thrown in parallel by a system condition modification operation device 4 and sets frequency and voltage phase as the values for standby.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power system controller for controlling frequency and voltage of a power system.

[0002]

2. Description of the Related Art If the frequency of the electric power system fluctuates, the rotational speed of the electric motor fluctuates and the indication value of time fluctuates, which has a great influence on industry and daily life. Therefore, it is necessary to keep the frequency constant at the target value. By the way, the frequency of the power system decreases when the power demand exceeds the generated power, and rises when the power demand becomes less than the generated power. Further, it is well known that the electric powers shared by the respective power generation facilities are unbalanced in response to the difference in the rotational speed of the respective power generation facilities connected in parallel to the power transmission line and operating in parallel.

Therefore, the frequency of the power system, which is determined by the balance between the power output from each power generation facility and the power demand on the load side, is monitored at the central control station, and the power generated by each power generation facility is monitored by the central control station. The current state of frequency control of electric power systems is to maintain the frequency near a specified value by adjusting it based on a command.

[0004]

As described above, the frequency of the electric power system is determined by the balance between supply and demand of electric power in the electric power system. Therefore, if the power supply / demand balance is disrupted due to fluctuations in the power demand of the load or a decrease in the generated power (for example, the power generation equipment is disconnected from the power grid), frequency fluctuations and voltage fluctuations occur in the power grid. Then, it takes time until these fluctuations are converged and settled to a stable state, and there is a disadvantage that the fluctuation of the entire system continues for a long time.

Further, when the power generation facility disconnected from the power system is re-introduced into the power system, the output voltage, voltage phase and frequency of the power generation facility must be matched with the values at the connection ends of the power transmission line. If there is power fluctuation in the system, the voltage of the transmission line is unstable. Therefore, it takes time to put the power generation equipment into the power system. When a large number of power generation facilities are cut off from the grid in a large area, the voltage of the transmission line has not been established, so it takes a longer time before all the power generation facilities are put into the power grid and run in parallel. become.

Therefore, an object of the present invention is to suppress the sway of the power system when the supply and demand balance is disturbed, and to promptly reconnect the power generation equipment disconnected from the power system to the system.

[0007]

In order to achieve the above-mentioned object, a power system control device of the present invention includes a plurality of power transmission lines for transmitting power generated by parallel operation of a plurality of power generation facilities to a demand area, and a plurality of these power transmission lines. In a power system configured with a plurality of substations connected to each transmission line to supply electric power to a load, generated power and voltage of each power generation facility, received power and voltage of each substation, each power generation facility And a data communication line for transmitting the connection state of the switch connecting each substation and each transmission line and the connection state of the switch connecting each transmission line to the central control device, and the data communication line. A central control device having a system condition calculating device for inputting the data obtained through the above and calculating instruction values of the voltage, frequency and voltage phase output by each power generation facility connected to each transmission line, and Access to power generation equipment and central control unit A reference clock that gives a time that serves as a reference for the number and the voltage phase, and an instruction value communication line that transmits the instruction value calculated by the system condition calculation device to each power generation facility connected to the power transmission line. And

Alternatively, the generated power and voltage of each of the power generation equipment,
The central control unit controls the received power and voltage of each substation, the connection state of switches for connecting each power generation facility and each substation to each transmission line, and the connection state of switches for connecting each transmission line to each other. A system for inputting data obtained through the data communication line and a data communication line to be transmitted to the data communication line, and calculating instruction values of the voltage, frequency and voltage phase output by each power generation facility connected to the power transmission line. A central control device equipped with a condition calculation device, and a voltage and frequency output by each power generation facility that is installed in the central control device and inputs data obtained through the data communication line, and is connected to each power transmission line. And a system condition change calculation device for calculating the indicated value of the voltage phase, a reference clock for giving time as a frequency and voltage phase reference to each of the power generation equipment and the central control device, the system condition calculation device and system condition change Arithmetic unit There shall be provided with the instruction value calculated, and a command value communication line for transmission to the respective power generation equipment will be connected to the transmission line and the power generation equipment that is connected to the transmission line.

[0009]

[Function] The frequency of the power grid is determined by the power supply and demand balance between the generated power of the power generation facility connected to the transmission line and the power consumed through the substation connected to the transmission line, and the inertia of the power generation facility. It depends on the constant and. Therefore, the central control unit inputs various data such as electric power, voltage and connection status of each power generation equipment and each substation obtained through the data communication line.
The system condition computing device receives these various data and the time signal from the reference clock, and sends out a separate output frequency instruction value and a separate output voltage phase instruction value to each power generation facility via the instruction value communication line.

For the power generation equipment to be connected in parallel to the electric power system, the system condition change computing device calculates in advance the expected state when the power generation equipment is connected in parallel to the power system.
The power generation equipment is put into a calculated state and put on standby.

[0011]

1 is a block circuit diagram showing a first embodiment of the present invention. In the first embodiment circuit of FIG. 1, the first power plant 10 and the second power plant 20 are operating in parallel via the circuit breakers 11 and 21, and the power generated by both power plants is transmitted to the power transmission and distribution system 6. Has been sent out. A substation 40 is connected to the power transmission and distribution system 6 via a circuit breaker 41, and the generated power is supplied from the substation 40 to a load (not shown). Here, various data such as the power output from the first power plant 10, the voltage, and the state of the circuit breaker are sent to the central control unit 2 via the data communication line 7. For the second power plant 20 and the substation 40, the data communication line 7 sends the same data to the central control unit 2.

The system condition computing unit 3 installed in the central control unit 2 inputs the reference time t from the reference clock 5 and also inputs the above-mentioned data via the data communication line 7 to balance the supply and demand of electric power. In response to the above, the reference time t and the frequency instruction value F described above are sent to each power station via the instruction value communication line 8, and the voltage phase instruction value δ ₁ is sent to the first power station 10 and the frequency phase instruction value δ 2 is sent to the second power station. The voltage phase indication value δ ₂ is sent to the power plant 20 via the indication value communication line 8.

Each power plant uses the received frequency instruction value F as a conventional frequency set value, and determines the difference between the voltage phase instruction value δ ₁ or the voltage phase instruction value δ ₂ and the voltage phase at the power station end by the conventional power generation instruction. Drive as a value. FIG. 2 is a block circuit diagram showing a second embodiment of the present invention. The second embodiment circuit of FIG. 2 is the same as the first embodiment circuit of FIG. A place 30 and a circuit breaker 31 are added. Therefore, the description of the same parts as those of the first embodiment circuit is omitted.

In the second embodiment circuit of FIG. 2, the first power plant 1
0 and the second power plant 20 are operated in parallel to send the generated power to the power transmission and distribution system 6, but the circuit breaker 31 is open, so the third power plant 30 has not yet been input to the system. .
As mentioned above, the 3rd power plant 3
It is not easy to connect 0 to the transmission and distribution system 6 in parallel. Therefore, the system condition changing arithmetic unit 4 is installed in the central control unit 2, and the voltage phase instruction value δ when the circuit breaker 31 is turned on.
₃ is calculated in advance by the system condition change calculation device 4, and the frequency and voltage phase of the third power plant 30 are calculated and kept in standby.

[0015]

According to the present invention, the central control unit obtains data such as the state of the power generation equipment or substation connected to the power transmission and distribution system using the data communication line and the power supply and demand balance and the reference time t. Incorporation into each power generation facility, and by giving the frequency command value of each power generation facility and the separate voltage phase command value of each power generation facility to each power generation facility via the command value communication line, it is possible to suppress the fluctuation of the power system. To be Further, there is an effect that the operation of inserting the power generation equipment into the electric power system in parallel can be quickly performed.

[Brief description of drawings]

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

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

[Explanation of symbols]

 2 Central control device 3 System condition calculation device 4 System condition change calculation device 5 Reference clock 6 Transmission and distribution system 7 Data communication line 8 Indication value communication line 10 1st power plant 20 2nd power plant 30 3rd power plant 40 Substation

Claims (2)

[Claims] 1. A plurality of power transmission lines for transmitting power generated by parallel operation of a plurality of power generation facilities to a demand area, and a plurality of substations connected to these power transmission lines to supply power to a load. In the power system, the generated power and voltage of each power generation facility, the received power and voltage of each substation, the connection state of each power generation facility and the switch that connects each substation and each transmission line, and each transmission line The connection state of the switches connecting each other, and a data communication line for transmitting to and to the central control unit, and the data obtained via the data communication line are input,
A central control device equipped with a system condition computing device that computes a voltage output by each power generation facility connected to each power transmission line, a frequency, and an indication value of a voltage phase, and a frequency to each power generation facility and the central control device. And a reference clock for giving a time as a reference of the voltage phase, and an instruction value communication line for transmitting the instruction value calculated by the system condition calculation device to each power generation facility connected to the power transmission line. A power system control device characterized by the above. 2. A plurality of power transmission lines for transmitting power generated by parallel operation of a plurality of power generation facilities to a demand area, and a plurality of substations connected to these power transmission lines to supply power to a load. In the power system, the generated power and voltage of each power generation facility, the received power and voltage of each substation, the connection state of each power generation facility and the switch that connects each substation and each transmission line, and each transmission line The connection state of the switches connecting each other, and a data communication line for transmitting to and to the central control unit, and the data obtained via the data communication line are input,
A central control device equipped with a system condition computing device that computes voltage, frequency, and voltage phase indication values output by each power generation facility connected to each power transmission line; and the data communication installed in the central control device. Inputting data obtained through the line, a system condition change calculation device that calculates the voltage, frequency, and voltage phase instruction value output by each power generation facility that is to be connected to each transmission line, and each power generation facility and the central unit A reference clock that gives a time that is a reference of frequency and voltage phase to a control device, and the instruction value calculated by the system condition calculation device and the system condition change calculation device, and each power generation facility connected to the power transmission line. And an instruction value communication line for transmitting to each power generation facility to be connected to the power transmission line.