JPH0530136B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a synchronization device that automatically closes different power transmission systems in synchronization.

[Conventional technology]

FIG. 5 is a block connection diagram of a conventional synchronization device disclosed in, for example, Japanese Unexamined Patent Publication No. 55-109135. In the figure, 1a and 1b are generators No. 1 and No. 2, respectively, and 5a and 5b are 1 generator each
No. 1 circuit breaker and No. 2 circuit breaker for turning on and shutting off the power corresponding to a and 1b, 5c is a bus circuit breaker that closes or opens the bus bars, 7 is a transformer for detecting voltage and frequency, Reference numeral 12 designates an arithmetic circuit that computes data input through the analog-to-digital conversion circuits 16a and 16b, and 13 an output circuit that outputs an on/off signal to the bus circuit breaker 5c based on the result of the arithmetic circuit 12. Note that the analog/digital conversion circuits 16a and 16b are connected to the generator 1, respectively.
The voltage and frequency of a and 1b are digitally converted.
6a and 6b are No. 1 and No. 2 bus loads. Further, the procedure of the control program in the arithmetic circuit 12 of FIG. 5 is shown in the flowchart of FIG. 6.

Next, the operation will be explained. In Figure 5,
When closing the bus circuit breaker 5c, if the No. 1 and No. 2 generators 1a and 1b are already in operation and the corresponding No. 1 and No. 2 circuit breakers 5a and 5b have been closed, the synchronization is performed. input is required. In this case, the voltage and frequency of the generators 1a and 1b are input to the arithmetic circuit 12 via the transformer 7 and the analog/digital conversion circuits 16a and 16b in response to a closing command for the bus circuit breaker 5c. Based on these data, the arithmetic circuit 12 executes control according to a program procedure according to the flowchart shown in FIG. That is, first, confirm the establishment of the closing voltage of the bus circuit breaker 5c, match the voltage and frequency of each of the generators 1a and 1b, and if these are within the tolerance, the next synchronization point, that is, the phase The time until the matching point is predicted, and when the predicted time falls within the allowable value, a closing signal is output to the bus circuit breaker 5c through the output circuit 13 to close the circuit breaker.

[Problem that the invention seeks to solve]

Since the conventional synchronization device is configured as described above, the generators 1a and 1b have the frequency regulation rate and voltage droop characteristics as shown in FIGS. 2 and 3.
In synchronized closing, the voltage and frequency are the same, so for example, if one generator is placed in a no-load state and the bus circuit breaker 5c is closed, the load will not be transferred to the unloaded machine, resulting in the worst case scenario. This may become a reverse power and trip the bus circuit breaker 5c. In addition, since the load becomes unbalanced immediately after the power is turned on, it takes a long time for the control operation to equalize the load sharing, resulting in problems such as a delay in stabilizing the system.

This invention was made to solve the above-mentioned problems, and takes into consideration the voltage and frequency as well as the active power and reactive power of both generators, and balances the load of both generators immediately after turning on. At the same time, in combination with a governor and automatic voltage regulator that have input terminals for the reference frequency and reference voltage, a synchronization start-up device outputs the reference frequency and reference voltage setting signals immediately after turning on, and can immediately adjust to the reference voltage and reference frequency. The purpose is to obtain.

[Means for solving problems]

The synchronization device according to the present invention uses a power detector to determine the active power and reactive power of generators in different power transmission systems, and before closing a circuit breaker for closing these different power distribution systems, The generators with larger power and reactive power are controlled to match the preset reference frequency and reference voltage, and conversely, the generators with smaller power are controlled to match the reference frequency and voltage higher than the reference frequency and voltage. It was designed to be controlled.

[Effect]

In this invention, synchronization is performed in a generator with a predetermined frequency regulation rate and voltage droop characteristics, for example, with the No. 1 generator at 40% load and the No. 2 generator at 40% load.
If you want to connect both generators in parallel while operating at 60% load, adjust the voltage and frequency of each generator to the specified values in advance before connecting them in parallel, and then synchronize them. . After this synchronization, the load shifts according to the regulation rate and drooping characteristics unique to each generator, and becomes 50%-50%.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In Figure 1, 1a and 1b are generators No. 1 and 2, respectively, 2a and 2b are automatic voltage regulators of No. 1 and No. 2, respectively, and 3a and 3b are generators for driving generators 1a and 1b, respectively. prime mover, 4
a, 4b are governors 1 and 2, respectively, and 5
Reference characters a, 5b, and 5c are generators 1a, 1b and bus circuit breakers, respectively, and 6a, 6b are loads for the No. 1 bus 15a and the No. 2 bus 15b, respectively. 7 is a transformer for voltage and frequency detection, 8 is a current transformer for current detection, and 9a and 9b are 1 for detecting active power and reactive power using the voltage from the transformer 7 and the current from the current transformer 8. No. and No. 2 power detector, 10
11 is a voltage/frequency/phase detection circuit that detects voltage, frequency, and phase, respectively; and 11 is a power detector 9.
a, 9b and the analog data of the voltage/frequency/phase detection circuit 10 are converted into digital data.
A digital conversion circuit 12 is an arithmetic circuit that receives data from the analog-to-digital conversion circuit 11 and performs arithmetic operations for synchronization; 13 is an arithmetic circuit that receives output commands from the arithmetic circuit 12 and includes governors 4a, 4b and an automatic voltage regulator 2a; 2b, an output circuit that outputs a signal to control the power detectors 9a and 9b;
The synchronization device of the present invention includes a phase detection circuit 10, an analog/digital conversion circuit 11, an arithmetic circuit 12, and an output circuit 13. Figures 2 and 3
The figure shows a generator 1a controlled by this synchronization device,
1b shows the regulation rate characteristics and voltage droop characteristics. Also,
The control program procedure for the arithmetic circuit 12 is shown in the flowchart of FIG.

Next, the operation will be explained. Busbar circuit breaker 5c
1 and 2 generators 1.
a and 1b are in operation, and No. 1 and No. 2 circuit breakers 5
If a and 5b are on, synchronization is required.
In this case, due to the closing command, the generator power of the systems on both sides of the bus circuit breaker 5c is detected as active power and reactive power by the power detectors 9a and 9b through the transformer 7 and current transformer 8. The generator voltage, frequency, and phase are detected by a voltage, frequency, and phase detection circuit 10. These data are converted into digital signals by the analog-to-digital conversion circuit 11, and then input to the arithmetic circuit 12, and the fourth
Processing is performed according to the control program procedure shown in the figure. First, it is checked whether the voltage and frequency of both generators 1a and 1b to be connected in parallel are far from the standard value. For automatic voltage regulators 2a, 2b, for frequency, governor 4a,
4b respectively. Next, compare the active power and reactive power of both generators 1a and 1b to be paralleled (when comparing, consider not only the absolute value of each power but also the sign), and find that the reactive power is large. The corresponding automatic voltage regulator 2a or 2b is controlled so that the voltage on the lower side becomes the reference voltage, and the voltage on the smaller side becomes slightly higher than the reference value. Further, in the case of active power, the corresponding governor 4a or 4b is similarly controlled so that the larger side becomes the reference frequency, and the smaller side becomes slightly higher than the reference frequency. the result,
When the voltage and frequency of both generators 1a and 1b remain within the allowable range from the reference value, and the voltage difference and frequency difference between the two generators fall within the allowable range, phase difference detection is performed.
In order to close the circuit breaker 5c at the phase matching point, a closing signal is outputted through the output circuit 13 within a certain period of time, taking into account the operating time of the circuit breaker 5c. In this way, the circuit breaker 5c is closed, and when the closing is completed, a signal for setting the reference voltage is output to the governors 4a, 4b of both generators 1a, 1b and the automatic voltage regulators 2a, 2b.

In the above embodiment, the generators 1a and 1b are driven by the prime movers 3a and 3b, but a motor generator driven by a motor or the like may be used, and the same effect can be obtained.

[Effects of the Invention] As described above, according to the present invention, it is determined whether the voltage and frequency detected by the voltage/frequency/phase detector are within a reference value, and if the voltage is not within the reference value, If the frequency is not within the standard value, the automatic voltage regulator of the generator will control the generator governor to bring it within the standard value, and the active power and reactive power of each generator detected by the power detector will be adjusted. The automatic voltage regulator is controlled so that the voltage on the side where the reactive power is larger is equal to the reference voltage, and the voltage on the side where the reactive power is smaller is slightly higher than the reference voltage, and the active power is larger. The governor is controlled so that the frequency on the side coincides with the reference frequency, and the frequency on the side where the active power is small is slightly higher than the reference frequency, and the voltage, frequency,
Since the configuration is such that the bus circuit breaker is closed when the phases at both ends of the bus circuit breaker detected by the phase detector match, the power on the side where each power is high decreases, and the power on the side where each power is low decreases. As a result, the time required to reach load balance after the bus circuit breaker is turned on becomes faster, and reverse power and overload of each power can be prevented immediately after the bus circuit breaker is turned on. .

[Brief explanation of the drawing]

FIG. 1 is a block connection diagram of a synchronization device according to an embodiment of the present invention, FIGS. 2 and 3 are characteristic diagrams of the frequency regulation rate and voltage droop of the target generator controlled by the present invention, and FIG. 4 is a flow diagram showing the procedure of a control program executed by the arithmetic circuit of the present invention,
Figure 5 is a block connection diagram of a conventional synchronization device.
FIG. 6 is a flowchart showing the procedure of a control program executed by a conventional synchronization input device. 1a, 1b are generators, 2a, 2b are automatic voltage regulators, 3a, 3b are prime movers, 4a, 4b are governors, 5a, 5b, 5c are circuit breakers, 9a, 9b are power detectors, 10 is voltage/frequency・Phase detection circuit,
12 is an arithmetic circuit, and 14 is a synchronization device. In addition, in the figures, the same reference numerals refer to the same or corresponding parts.

Claims (1)

[Claims] 1. A power detector that detects the active power and reactive power of the generator connected to both ends of the bus circuit breaker installed on the bus, and a voltage that detects the voltage, frequency, and phase at both ends of the bus circuit breaker. ·frequency·
It is determined whether the voltage and frequency detected by the phase detector and the voltage/frequency/phase detector are within a reference value, and if the voltage is within the reference value, the automatic voltage regulator of the generator and its If the frequency is not within the standard value, control the governor of the generator to bring it within the standard value, compare the active power and reactive power of each generator detected by the power detector, and determine whether the reactive power is The automatic voltage regulator is controlled so that the voltage on the larger side matches the reference voltage, the voltage on the side where the reactive power is smaller is slightly higher than the reference voltage, and the frequency on the side where the active power is larger is set as the reference frequency. The governor is controlled so that the frequency on the side where the active power is smaller is slightly higher than the reference frequency, and the voltage, frequency, and
A synchronization closing device comprising: an arithmetic circuit that closes the bus circuit breaker when phases at both ends of the bus circuit breaker detected by a phase detector match.