JPH06269129A - Parallel control apparatus of electric power system - Google Patents

Abstract

PURPOSE:To start a connecting operation to a system smoothly and with room by a method wherein information on system electric power and a generator part is input and a connection instruction is set to a connecting switch. CONSTITUTION:A system (a signal passage) 6 in which information on the frequency and the phase of an electric power supply system 1 is input to a drive-part control device 4 and a system (a signal passage) 7 in which information on the output (the frequency, the phase) of a generator 2 is input to the drivepart control device 4 are installed. Then, a connection timing which is optimum for the drive-part control device 4 is computed on the basis of the information from the two systems 6, 7, a control signal 12 is sent to a drive part 3 at the timing so as to eliminate a frequency difference, and a connection control signal is sent to a connecting switch 8. Thereby, a connecting operation to the system can be started smoothly and with room without giving an excessively sudden change to a plant after a setting operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a connection control mechanism of a power plant of a system in which a plurality of AC power are connected in parallel. For example, a drive unit control device in an AC power plant and a system parallel connection are provided. The present invention relates to a parallel control device for a power system applied to a verification device or the like.

[0002]

2. Description of the Related Art FIG. 4 shows an example of a conventional power supply system in which a plurality of such AC power supplies are connected in parallel.

Conventionally, a system frequency is assumed in advance,
On the other hand, the output of the plant is adjusted by giving a signal to the drive unit 3 so that the frequency difference from the system becomes appropriate while using it as the output of the plant. Also, when paralleling, the time when the phases of the two electric powers coincide is calculated back from the frequency difference, and the result is operated by the relay with timer to connect to the grid.

[0004]

For a power supply network based on a system, the quality of the output power source (stability of frequency) is the most important issue. However, in the conventional method, there is a limit to quality assurance due to the following problems.

(1) The drive device once settles to an output corresponding to the assumed frequency, regardless of the system frequency, and then adjusts the output to make the frequency with the system appropriate. Since the output is changed in a short time from the once settled state including the state of the plant, there is a possibility that the response characteristic to a sudden output change at the time of connection with the system may be deteriorated.

(2) In the conventional mechanism for phase-matching and closing, if the two frequencies do not differ to some extent, the operation cannot be performed in principle. However, it is desirable that the difference in frequency be extremely small or absent in consideration of shock and fluctuation to the system and plant. In this respect, the conventional method has a bottleneck.

(3) The connection timing to the system at the time of conventional phase matching is calculated backward from the frequency difference with the system, and after 2 seconds, 3
This is done by selecting a relay with a timer prepared in advance, such as seconds later. In this method, the connection timing is not properly performed at frequency differences other than the fixed time (the timing at which the relay is prepared),
This causes fluctuations on the plant side, fluctuations in the frequency of the system, etc., which leads to deterioration in the quality of the supplied power and deterioration in plant efficiency due to disturbances.

The present invention has been made in view of the above circumstances,
It is possible to smoothly enter into the connection operation with the system without giving an extra and sudden change to the plant after settling, and it is especially useful when applied to a plant that has a power generation part with a long time constant such as a boiler. It is an object of the present invention to provide a parallel control device for a power system. Another object of the present invention is to provide a paralleling control device for a power system, which can quantitatively grasp and control the impact shock at the time of paralleling.

Further, according to the present invention, even when an existing connecting device is diverted and used, the drive device adjusts the output in accordance with the characteristic timing, and the parallel connection control of the electric power system can accurately perform the system connection timing. The purpose is to provide a device.

[0010]

The present invention newly adopts the following technical means in order to solve the above-mentioned conventional problems. (A) A system for inputting system power information (frequency, phase) is provided in the drive unit controller. (B) The drive unit controller is provided with a system for inputting information (frequency, phase) of the generator output power.

(C) By configuring the drive unit controller to send a connection command to the connection switch, the settling target of the drive unit is automatically set according to the characteristics of the interface between the generator and the system and the system frequency at that time. The drive unit control device sets each time and system connection is performed.

That is, according to the present invention, as shown in FIG. 1, a generator 2 and its drive unit (motor) 3 and the same drive unit 3 are provided in a power supply system 1 to which output power of a plurality of generators is supplied. In a parallel mechanism for mutually connecting a power generation mechanism including a drive unit control device 4 to be controlled and a power supply connection switch 8, a system for inputting frequency and phase information of the power supply system 1 to the drive unit control device 4. (Signal path) 6 and output of generator (frequency,
A system (signal path) 7 for inputting phase) information to the drive unit control device 4 is provided, and the optimum connection timing is calculated for the drive unit control device 4 based on the information of these two systems (6, 7). However, a means is provided for sending the control signal 12 to the drive unit 3 and sending the connection control signal 11 to the connection switch 8 so that the frequency difference disappears at that timing.

[0013]

[Function] Both the system power information and the generator output power information (frequency, phase) are input to an arithmetic unit such as a calculator in the drive unit controller, and the drive unit outputs the following information based on the control output. Allows you to take control.

(A). Output accurate and optimal connection timing. That is, when the conventional timer is used, as shown in FIG.
As shown in FIG. -1), there is a disadvantage that a shift in the input timing occurs, but in the present invention, as shown in FIG. 2 (a-2), the processing means (computer) of the drive unit control device is accurate and optimal. Filling is completed at various connection timings.

(B). If there is an existing connection device, the state of the drive unit is adjusted so as to match the specific timing of the device. That is, when the conventional technique is used, a shift occurs as shown in FIG. 2 (b-1), but in the present invention, the output (frequency, phase) of the generator is adjusted by controlling the drive unit, and as shown in FIG. As indicated by B ′ in (b-2), the phase and the frequency are matched at the time of making. The drive unit is controlled so that B and B ′ disappear at the moment of turning on. (C) After the timing back calculation, the driving device is controlled so that the frequency difference disappears at that timing. The system connection can be accurately performed by sending a connection command from the drive unit control device to the connection switch after performing the above-described control of (a), (b), and (c).

That is, according to the present invention, the drive unit control device has a target necessary for system connection in advance by the constituent elements (A) and (C), so that an extra and abrupt change is given to the plant after settling. Instead, it is possible to enter the connection operation with the grid with a margin. This is particularly useful in a plant having a power generation unit with a long time constant such as a boiler. Further, by using the above means (A), (B), (C), (a), (c), it is possible to quantitatively grasp and control the impact shock at the time of paralleling.

Also, when applied to an existing connection device, the drive unit adjusts the output according to the characteristic timing by means (A), (B), (C), and (b), and system connection is performed. It is possible to accurately perform the timing of.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. A first embodiment of the present invention will be described with reference to FIG.

A plurality of power generation plants 9, 9, ... Are connected to the AC power supply system 1, and a generator 2 and a drive unit (motor) 3 for driving the generator 2 are connected to each of these power generation plants. , A drive unit control device 4 for controlling the drive unit 3, a system (signal path) 6 for inputting frequency and phase information of the power supply system 1 to the drive unit control device 4, frequency and phase information of the generator 2. System (signal path) 7 for input to the drive unit controller 4,
It is provided with components such as a connection switch 8 for supplying the output power of the generator 2 to the power supply system 1 and a power connection system 10.

The drive unit controller 4 calculates the optimum connection timing based on the information of each system (signal paths 6 and 7), and sends a control signal to the drive unit 3 so that the frequency difference disappears at that timing. 12 and a processing device for sending a connection control signal 11 to the connection switch 8. Normally, the generator 2 controls the drive unit 3 such as a steam turbine or a gas turbine by the drive unit control device 4 and generates power by the drive force thereof.

The electric power output from the generator 2 passes through the electric power connection system 10 having the connection switch 8 and then the electric power supply system 1
However, it is necessary to match the phase and frequency at the time of input.

To this end, the generator 2 of the power connection system 10
Side output power information is configured to be sent to the drive unit control device 4 via the signal path 7, and system power information on the power supply system 1 side of the power connection system 10 is also provided via the signal line 6 to the drive unit. It is configured to be sent to the control device 4.

The drive unit controller 4, which has received the information on the two signal paths 6 and 7, compares the two phases and frequencies, and outputs the information on the output power of the signal path 7 to the information on the system power on the signal path 6. The control signal 12 is sent to the drive unit 3 to adjust the generator 2 via the drive unit 3 so as to match with. Generator 2
Is sent from the power connection system 10 via the signal line 7 to the drive unit controller 4 as output power information for comparison. After confirming that the above two pieces of information match, the connection command signal 11 to be supplied at the correct timing is sent to the connection switch 8 to perform the insertion. Next, a second embodiment of the present invention will be described with reference to FIG.

The configuration of the second embodiment shown in FIG. 3 is when an existing facility is used, and the information of the output power of the signal line 7 and the information of the system power of the signal line 6 are both connected to the interface. The signal 13 is sent to the drive unit controller 4 via the (connection I / F) 5 and the signal 11 such as the connection timing is also sent via the connection interface 5.

[0025]

As described above in detail, according to the present invention, since the drive unit control device has a target necessary for system connection in advance, a margin can be provided without giving an excessive and sudden change to the plant after settling. You can take the connection operation with the grid. Therefore, it is useful in a plant such as a boiler having a power generation part with a long time constant. In addition, it is possible to quantitatively grasp and control the impact shock at the time of paralleling.
Further, even when the existing connecting device is diverted and used, the drive device adjusts the output in accordance with the characteristic timing, and the timing of system connection can be accurately performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a power supply system of an AC power generation plant according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining an outline of technical means adopted in the present invention.

FIG. 3 is a block diagram showing a configuration of a power supply system of an AC power generation plant according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a power supply system of a conventional AC power generation plant.

[Explanation of Codes] 1 ... Power supply system, 2 ... Generator (G), 3 ... Drive unit, 4
... Drive unit controller, 5 ... System connection interface (I / F), 6 ... System power information (frequency, phase), 7
... Output power information (frequency, phase), 8 ... Connection switch, 9 ... Other power plant, 10 ... Power connection system, 11 ...
Connection command signal, 12 ... Control signal.

Claims (1)

[Claims] 1. A connection control mechanism between a generator and a power supply system for supplying the generator output to a power supply system that receives a plurality of generator outputs, and a drive unit for driving and controlling the generator. A connection switch for supplying the output of the generator to the power supply system, a signal path for obtaining the frequency and phase information of the power supply system, and a signal path for obtaining the frequency and phase information of the generator,
A drive unit controller for calculating an optimum connection timing based on the information of each signal path, controlling the drive unit so as to eliminate the frequency difference at that timing, and transmitting a connection signal to the connection switch. A parallel control device for a power system, which is characterized in that