JPS6268025A - Load sharing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a load sharing device that operates a plurality of generators in parallel.

[Conventional technology]

FIG. 2 is a circuit diagram showing a conventional load sharing device for multiple generators operating in parallel, as disclosed in, for example, Japanese Patent Application Laid-Open No. 511-36493.
) is the generator, (2a), (2b) is the prime mover, (3a),
(5b), (3C) are circuit breakers, (7a), (7b) are active power detectors for each power generation 1 (1a), (1b), (16a)
), (16b) are loads, and an is each generator (1a), (1
b) Average circuit for calculating the average value from the active power of (1sa
), (1sb) C is an operational amplifier that compares the active power of each generator (1a), (1b) with the average value determined by the averaging circuit (lη).

A conventional load sharing device is configured as described above, for example, the generator (1s, (1b) is connected to the loads (16a), (1b) with arbitrary power factors.
16b) and are running in parallel. In this case, the outputs of the active power detectors (7a) and (7b) are Va, vb,
If the output of the averaging circuit Qη is VM, then the operational amplifier (+a
Inputs Vra and Vrb of a) and (1ab) are set as shown by the following equation.

Vra=Va-VM・・・・・・・・・・・・(1
)Vra ” vb ”Jy ・”・”-・(21
Here, by substituting the above equation (3) into the equation fil, +2), it becomes.

On the other hand, the operational amplifiers (1aa) and (18b) have input Vra
, Vrb are zero, the output becomes zero only when Vrb is zero. Therefore, when Va > Vb, the operational amplifier (1aa
) acts on the prime mover (2a), generating electricity m (1a
) to reduce the speed of the operational amplifier (
The output signal of 18b) acts on the prime mover (2b) and acts in the direction of increasing the speed of the generator (1b). In this way, the conventional load sharing device
) is averaged, that is, the active power is divided.

[Problem that the invention seeks to solve]

Conventional load sharing devices are configured as described above, so when the bus connection circuit breaker is opened when the loads on each generator and bus are unbalanced, it causes disturbance to the system frequency and voltage. However, since the circuit is opened while the current is still flowing, it has a negative effect on the switch.

This invention was made to solve the above-mentioned problems, and it detects the active power and reactive power of the bus line, and in order to reduce these to zero, the load is divided among each generator, The purpose is to obtain a load sharing device that performs segmented operation and can freely shift from parallel to segmented operation.

[Means for solving problems]

The load sharing device according to the present invention detects the active power and reactive power of the busbar connection line, determines which generator has large or small active power and reactive power from the direction of this active and reactive power, and In order to reduce the power to zero, the generator on the side with larger active power or reactive power reduces its share by the active/reactive power valve of this bus connection line, and conversely, the generator on the side with less active power or reactive power reduces the share by the active/reactive power valve of this bus connection line. The amount shared by only the reactive power valve is increased.

[Effect]

The load sharing device d in this invention increases or decreases the sharing setting value of the generators running in parallel only by the active and reactive power valves of the bus line connecting line, and finally brings the active and reactive power of the bus line connecting line to zero. Even if a system abnormality occurs, sectional operation can be performed immediately.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (1a) and (1b) are generators, (2a),
(2b) is the prime mover, (3a), (3b), (3C) are circuit breakers, (4a), (4b), (4 is a transformer, (5a)
, (5b), (5C) are current transformers, (6) are active power detectors (7a), (7b), (7C), and reactive power detectors (8
a), (8b), (8) This is a load sharing device consisting of an analog input circuit (9), a generator sharing amount setting circuit a [and a digital output circuit αυ.Here, in the above configuration, (7a), ( 7b) is an active power detector for a generator; (7b) is an active power detector for a generator;
C) is the active power detector for the busbar connection line, (8a), (8
b) is a reactive power detector for the generator, (8C) is a reactive power detector for the bus connection line, and (9) is an active power detector (7a).
), (7b), (7C) and reactive power detector (sa),
The analog input circuit converts the outputs of (ab) and (8C) from analog to digital. A generator sharing amount setting circuit aD determines and sets the sharing amount of the generators (1B) and (1b), and in order to make the sharing amount set by the generator sharing amount setting circuit a1, (1b) A digital output circuit that controls the frequency and voltage, (12a) and (12b) are voltage increase signals that increase the voltage, (t5a) and (15b) are voltage decrease signals that decrease the voltage, (i4a), (ub) is a frequency increasing signal that increases the frequency, (1sa), (1s
b) is a frequency down signal that lowers the frequency.

Next, the operation will be explained. Generator running in parallel (1a
), (1b) and the active power and reactive power of (100) of the busbar connection line are transmitted through transformers (4a), (4b), (4C) and current transformers (5a), (5b), (5C). , active power detectors (7a), (7b), (7C) and reactive power detectors (8a), (8b), (8C). These are converted into digital data by an analog input circuit (9) and input to the next generator sharing amount setting circuit θO. In this setting circuit arp, the active power of the generators (1a) and (1b) is Pl, P2, the reactive power is Ql, Q2, and the active power of the bus connection line (1oo) is Pa1, and the reactive power is QB. (1a), (1b) active power and reactive power new shared company setting values WSP1, WSP2 and WsQl,
W S Q 2 is set as follows.

In other words, Wspl is WSPI "PI PBWSF, assuming that the active power and new shared amount setting values of the generator (1a) on the side where PB flows are P1 and WSPI, respectively.
'2 is, assuming that the active power and new shared amount setting values of the generator (1b) on the side where pa flows are valleys P2 and W8P2...
・・・・・・WSP2− P2+PBWsc)1 is
If the reactive power and new shared amount setting values of the generator (1a) on the side where QB flows are Q1 and WsQl, respectively, ゛""""
WSQ1 = Q 1 - QBW sg 2 is the reactive power of the generator (1b) on the side where Qa flows and if the new share share setting values are respectively Q2 and WSQ2......W
SQ2 = Q2 +QB That is, the active power share of the generator (1a) on the side where PB flows decreases, and PB is zero,
The frequency falling signal (15
a) is stopped, and the active power share of the generator (1b) on the side into which PB flows increases, and when the same <Pa is zero, the frequency increase signal (14b) is stopped via the digital output circuit 0υ. The same goes for the case of reactive power sharing; the reactive power sharing amount of the generator (1a) on the side where QB flows decreases, and when QB is zero, a voltage reduction signal (15a) is sent via the digital output circuit 0υ.
). The reactive power share of the generator (1b) on the side into which Qa flows increases, and when QB is zero, the voltage increase signal (12b) is stopped via the digital output circuit aυ.

In this way, load sharing is performed to reduce the active power and reactive power of the bus line to zero.

In the above embodiment, the case where two generators are operated in parallel has been described, but three or more generators may be operated in parallel, and the same effects as in the above embodiment can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, the load sharing device is configured so that the active power and reactive power of the busbar connection line are always zero, so that even if an abnormality occurs in the grid during parallel operation, sectional operation can be immediately started. That is, it is possible to obtain a load sharing device that can divide the load according to the generator without causing disturbance to the system frequency and voltage, and also to obtain a highly reliable power distribution system.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a load sharing device according to an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional load sharing device. (1a) and (1b) are generators, (6) is a load sharing device,
(7a), (7b), (7C) are active power detectors, (8
a), (8b), (8C) are reactive power detectors, (9) is an analog input circuit, al is a generator sharing amount setting circuit, 0υ
is a digital output circuit, and (100) is a bus connection line. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. (Two other people)
No. 5 No. 2, Name of the invention Load sharing device 3, Representative of the person making the amendment Mamoru Shiki +11 (4, Agent Postal code 105 Address
Bundle μ; (Nishishinbashi, Miyakominato-ku) 1 [No. 14, No. 10-5, Subject of amendment (1) Column for detailed explanation of the invention in the specification (2) Drawing 6, Contents of amendment (1) Specification 3rd ward, 3rd line, rVraj
Correct rbJ (2) Correct Figure 1 as shown in the attached sheet. 7. One or more documents containing the amended Figure 1 of the attached documents

Claims (1)

[Claims] In a load sharing device that operates a plurality of generators in parallel and shares the load of the generators, an active power detector and a reactive power detector that detect active power and reactive power of the plurality of generators and bus bar connection lines; , an analog input circuit that converts the outputs of the active power detector and the reactive power detector from analog to digital, a generator sharing amount setting circuit that sets the sharing amount of each generator, and this generator sharing amount setting circuit. a digital output circuit that increases or decreases the speed of the prime mover and the voltage of the generator from the output; A load sharing device characterized in that the generator sharing amount setting circuit is configured to operate in parallel via the digital output circuit so that the generator sharing amount setting circuit becomes zero.