JP2011211845A - Synchronism testing system of generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a compulsory speed control circuit which is required in a conventional case and to simplify a control circuit in synchronous input of a generating set.SOLUTION: In a synchronism testing system of the generator including a synchronous input device 5 deploying the generator 2 in a power system 1, the synchronism input device 5 includes: a frequency difference detector detecting a frequency difference between generator voltage and a bus-bar voltage; and a frequency deviation determiner determining whether the frequency difference detected by the frequency difference detector is within a reference value or not. When a frequency of the generator voltage is higher than the bus-bar voltage, a first upper limit value and a first lower limit value, which have positive values, are set as reference values in the frequency deviation determiner. The synchronism input device 5 outputs an input command when the frequency difference is between the first upper limit value and the first lower limit value, and controls the output frequency of the generator so that the frequency difference becomes the upper limit value or below by outputting a governor decrease command when the frequency difference is the upper limit value or above, and so that the difference becomes the lower limit value or above by outputting a governor increase command when the difference is the lower limit value or below.

Description

  The present invention relates to a generator synchronous verification method for, for example, supplying a generator used as an emergency power generation facility to an electric power system (generator main bus).

Conventional synchronous input device for shortening the time required for the generator to be turned on after the voltage of the power system (hereinafter also referred to as “generator main bus”) is synchronized with the voltage of the generator As disclosed in, for example, Patent Document 1 and Patent Document 2.
Patent Document 1 discloses that when the voltage value difference, the frequency difference, and the phase difference between the voltage of the power system and the voltage of the synchronous generator are all within predetermined reference values, the synchronous generator and the power In the synchronous closing device that turns on the synchronous generator to the power system by turning on the circuit breaker that connects the system, when the closing coil that turns on the circuit breaker when energized, the contact switch and the thyristor switch are both turned on When the voltage value difference and the frequency difference are within the reference values, the contact switch is turned on. When the voltage value difference, the frequency difference and the phase difference are within the reference values, the thyristor is turned on. The switch is configured to be turned on.

  Further, in Patent Document 2, the output voltage of a plurality of generators and the voltage of a power line (power system) are input to a synthesis circuit to detect a frequency difference, and the frequency difference satisfies a synchronization condition. Otherwise, the control pulse is output from the frequency difference command output circuit or kick circuit to control the governor motor, and when the synchronization condition is satisfied, the synchronization signal is output from the synchronization point input signal output circuit and the combined generator selection switch is The circuit breaker of the generator and the synchronous switching circuit parallel to the circuit breaker are simultaneously turned on, and the selection switch is turned off when the insertion is completed.

JP-A-9-149555 Japanese Unexamined Patent Publication No. 4-200243

  FIG. 5 shows an example of uniform speed control (synchronous verification) in Patent Document 1. In this conventional apparatus, the input range is within ± 0.2 Hz with the difference between the generator frequency and the bus frequency exceeding 0 Hz. Therefore, there is a possibility that the frequency difference falls within ± 0.5 Hz, which takes time for synchronization verification. When the frequency difference falls within ± 0.5 Hz, the change in the phase difference is reduced, and it takes time until the circuit breaker is turned on. In addition, a forced speed control by a kick circuit for driving out the frequency difference from ± 0.5 Hz is required separately.

  FIG. 6 shows an example of uniform speed control (synchronization verification) in the above-mentioned Patent Document 2. In this conventional apparatus, the range within ± 0.1 Hz is further forced from the range where synchronization can be applied (within ± 0.2 Hz). By removing the frequency difference, 0.1 to 0.2 Hz and −0.1 to −0.2 Hz are set in a synchronizable range. Therefore, in this conventional apparatus, since there are two possible input ranges, a forced speed control circuit by a kick circuit is required, and two controls of frequency difference control and forced speed control are inherent, and the control circuit is complicated. It had the subject of becoming.

  The present invention has been made to solve the above-described problems, eliminates the need for a forced governing control circuit that has been conventionally required, simplifies the control circuit, and enables a reduction in synchronization verification time. The purpose is to provide a synchronous verification method for the generator.

The generator synchronous verification method according to the present invention includes a bus voltage detector for detecting a voltage of an electric power system (generator main bus), a generator voltage detector for detecting an output voltage of the generator, and both voltage detectors. When the detection voltage is input, and the voltage value difference, the frequency difference, and the phase difference between the bus voltage and the generator voltage are all within predetermined reference values, the interruption connecting the generator and the power system is cut off. In the generator synchronous verification system that includes a synchronous input device that gives an input command to the generator and inputs the generator into the power system, the synchronous input device detects a frequency difference between the generator voltage and the bus voltage. A difference detecting means and a frequency deviation determining means for determining whether the frequency difference detected by the frequency difference detecting means is within a reference value, wherein the frequency deviation determining means is a frequency of the generator voltage with respect to the bus voltage. Is high Case, the first lower limit value having a first upper limit value and a positive value having a positive value is set as a reference value,
The synchronous closing device outputs a closing command to the circuit breaker when the frequency difference between the generator voltage and the bus voltage is between the first upper limit value and the first lower limit value, and the frequency difference However, if it is greater than or equal to the upper limit value, the governor reduction command is output to the upper limit value or less, and if it is equal to or less than the lower limit value, the governor increase command is output to set the output frequency of the generator to be equal to or greater than the lower limit value. It is intended to be controlled.

The generator synchronous verification method according to the present invention includes a bus voltage detector for detecting a voltage of a power system (generator main bus), a generator voltage detector for detecting an output voltage of the generator, and both voltage detections. When the detection voltage from the generator is input and the voltage value difference, frequency difference, and phase difference between the bus voltage and the generator voltage are all within predetermined reference values, the generator and the power system are connected. In a synchronous verification system of a generator provided with a synchronous input device that supplies a closing command to the circuit breaker that performs the operation, the synchronous charging device detects a frequency difference between the generator voltage and the bus voltage. And a frequency deviation determining means for determining whether the frequency difference detected by the frequency difference detecting means is within a reference value, wherein the frequency deviation determining means is a generator voltage with respect to the bus voltage. Frequency If is low, the second lower limit is set as a reference value having a second upper value and a negative value having a negative value,
The synchronous closing device outputs a closing command to the circuit breaker when the frequency difference between the generator voltage and the bus voltage is between the second upper limit value and the second lower limit value, and the frequency difference However, if it is greater than or equal to the upper limit value, the governor reduction command is output to the upper limit value or less, and if it is equal to or less than the lower limit value, the governor increase command is output to set the output frequency of the generator to be equal to or greater than the lower limit value. It is intended to be controlled.

  According to the generator synchronous verification method of the present invention, there is an effect that the forced adjustment control circuit, which has been conventionally required, is unnecessary, and a simple control circuit can perform the synchronous input in a short time and surely. is there.

  The above-described and other objects, features, and effects of the present invention will become more apparent from the detailed description and the drawings in the following embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS It is a system whole figure which shows the whole structure of the synchronous verification system of the generator in Embodiment 1 of this invention. It is a figure which shows an example of the uniform speed control of the synchronous injection | throwing-in apparatus in Embodiment 1 of this invention. It is a figure which shows an example of the uniform speed control of the synchronous injection | throwing-in apparatus in Embodiment 2 of this invention. It is a figure explaining the relationship between the frequency difference in synchronous addition, and the time interval from a synchronization point to a synchronization point. It is a figure which shows an example of the uniform speed control of the conventional synchronous injection | throwing-in apparatus. It is a figure which shows another example of the uniform speed control of the conventional synchronous injection | throwing-in apparatus.

Embodiment 1 FIG.
1 is an overall system diagram showing an overall configuration of a generator synchronous verification system according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 1 denotes a charged main circuit bus that is a power system. When power is transmitted to the main circuit bus 1 from a private power generator (hereinafter simply referred to as a generator) 2, the bus voltage detector 3 is used. And each voltage is detected by the generator voltage detector 4 and inputted to the synchronous input device 5. As is well known, the synchronizer 5 includes a generator main circuit 6 when the voltage value difference, frequency difference, and phase difference between the input bus voltage and the generator voltage are all within a predetermined reference value. An input command is given to the circuit breaker 7 connected to the main circuit bus 1, and the generator 2 is input to the main circuit bus 1. The synchronous input device 1 includes the voltage of the generator 2 and the voltage of the bus 1. A frequency difference detecting means (not shown) for detecting the frequency difference between the frequency difference and a frequency deviation determining means for determining whether the frequency difference detected by the frequency difference detecting means is within a reference value described later ((FIG. Not shown).

Next, the uniform speed control (synchronization verification) by the synchronous input device as the main part of the present invention will be described with reference to FIG.
FIG. 2 is a control example of the first embodiment of the present invention, particularly a setting example in which the generators are synchronously supplied, and is intended to be supplied on the FAST side where the generator frequency is higher than the bus frequency. Is. In other words, the frequency deviation determination means of the synchronous input device 5 sets the lower limit of the frequency difference as +0.1 Hz and the upper limit as +0.2 Hz as the input possible range.
When the frequency difference (generator frequency−bus frequency) is +0.1 Hz or less, the synchronous input device 5 gives a governor increase command to the power generator 2, and when it is +0.2 Hz or more, the power generator 2 is configured to output a governor reduction command to control the generator frequency so that the frequency difference falls within the possible input range.

  Therefore, according to the first embodiment of the present invention, there is no need to provide a forced speed control means (kick circuit) particularly in the vicinity of a frequency difference of 0 Hz as in the prior art, and a simple control circuit can be used for a short time for synchronization. In addition, it is possible to obtain a generator synchronous verification method that can be performed reliably.

Embodiment 2. FIG.
FIG. 3 shows an example of control according to Embodiment 2 of the present invention. In particular, FIG. 3 shows an example of setting when the generator is synchronized when the system is connected to a commercial power source. The generator frequency is lower than the bus frequency. It is intended to be input on the side. In other words, the frequency deviation determination means of the synchronous input device 5 sets the lower limit of the frequency difference as -0.2 Hz and the upper limit as -0.1 Hz as the input possible range.
Then, when the frequency difference (generator frequency−bus frequency) is −0.2 Hz or less, the synchronizing device 5 gives a governor increase command to the power generator 2, and when −0.1 Hz or more, It is configured to output a governor reduction command to the power generation device 2 and control the generator frequency so that the frequency difference falls within the possible input range.

  Therefore, in this second embodiment as well, it is not necessary to provide a forced speed control means (kick circuit) particularly in the vicinity of a frequency difference of 0 Hz as in the prior art. It is possible to obtain a generator synchronous verification system that can be reliably performed.

FIG. 4 illustrates the relationship between the frequency difference upon synchronization input and the time interval from the synchronization point to the synchronization point.
As is clear from FIG. 4, when the frequency difference is ± 0.05 Hz or less, the phase difference changes slowly (it does not change when the frequency is 0 Hz), so it takes time for the synchronization verification. On the other hand, when the frequency is ± 0.3 Hz or more, the frequency difference is large and the time can be shortened. However, the influence on the generator cannot be ignored at the time of synchronous input. Therefore, it is preferable to perform a synchronization test at about ± 0.1 to 2 Hz when the synchronization is applied.

1 Power system (main circuit bus)
2 In-house power generator 3 Bus voltage detector 4 Generator voltage detector 5 Synchronizing device 6 Generator main circuit 7 Breaker

Claims (4)

A bus voltage detector that detects the voltage of the power system (generator main bus), a generator voltage detector that detects the output voltage of the generator, the detection voltage from both voltage detectors is input, the bus voltage and the generator When the voltage value difference, the frequency difference, and the phase difference from the voltage are all within predetermined reference values, a closing instruction is provided to a circuit breaker connecting the generator and the power system, and the generator is In the synchronous verification method of the generator with the synchronous input device to be input to the power system,
The synchronous input device includes frequency difference detection means for detecting a frequency difference between the generator voltage and the bus voltage, and frequency deviation determination means for determining whether the frequency difference detected by the frequency difference detection means is within a reference value. Prepared,
When the frequency of the generator voltage is higher than the bus voltage, the frequency deviation determination means sets a first upper limit value having a positive value and a first lower limit value having a positive value as reference values. ,
The synchronous closing device outputs a closing command to the circuit breaker when the frequency difference between the generator voltage and the bus voltage is between the first upper limit value and the first lower limit value, and the frequency difference However, if it is greater than or equal to the upper limit value, the governor reduction command is output to the upper limit value or less, and if it is equal to or less than the lower limit value, the governor increase command is output to set the output frequency of the generator to be equal to or greater than the lower limit value. Synchronous verification system for generators, characterized by control. A bus voltage detector that detects the voltage of the power system (generator main bus), a generator voltage detector that detects the output voltage of the generator, the detection voltage from both voltage detectors is input, the bus voltage and the generator When the voltage value difference, the frequency difference, and the phase difference from the voltage are all within predetermined reference values, a closing instruction is provided to a circuit breaker connecting the generator and the power system, and the generator is In the synchronous verification method of the generator with the synchronous input device to be input to the power system,
The synchronous input device includes frequency difference detection means for detecting a frequency difference between the generator voltage and the bus voltage, and frequency deviation determination means for determining whether the frequency difference detected by the frequency difference detection means is within a reference value. Prepared,
The frequency deviation determining means sets a second upper limit value having a negative value and a second lower limit value having a negative value as reference values when the frequency of the generator voltage is lower than the bus voltage. ,
The synchronous closing device outputs a closing command to the circuit breaker when the frequency difference between the generator voltage and the bus voltage is between the second upper limit value and the second lower limit value, and the frequency difference However, if it is greater than or equal to the upper limit value, the governor reduction command is output to the upper limit value or less, and if it is equal to or less than the lower limit value, the governor increase command is output to set the output frequency of the generator to be greater than the lower limit value Synchronous verification system for generators, characterized by control.   2. The generator synchronous verification method according to claim 1, wherein the first upper limit value is set to 0.2 Hz, and the first lower limit value is set to 0.1 Hz.   3. The generator synchronous verification method according to claim 2, wherein the second upper limit value is set to -0.1 Hz and the second lower limit value is set to -0.2 Hz.

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