JPS6176030A - Power-supply changeover controller in station - 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] [! BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching control device for an in-house power source having a private generator.

[Technical background of the invention and its problems] In recent years, gas facilities for LNG gas, etc., are increasingly equipped with generator equipment that utilizes the heat of vaporization. In order to ensure the reliability of the power supply, gas equipment in-house power supply systems often receive power from two different commercial AC systems, and in this case, they generally have a power supply switching function within the facility. Normally, manual power switching is allowed within a certain range of phase difference between the relevant power supplies, but when a private generator is connected, the allowable phase difference is when switching power supplies with a normal load. While the allowable phase difference at the time is about ±20°, the range of the allowable phase difference is about ±5″.

In normal manual power switching, the voltage and phase difference are checked using a synchronization detection device, but there are few actual facilities that have a generator attached to the gas generation equipment within the gas facility, and most gas facilities probably do not. Currently, there is no problem because the power receiving system is receiving power from multiple systems with the same phase.

Moreover, if you have a generator that uses the heat of vaporization at a gas facility that receives power from two lines from different systems, and the generator is connected in parallel to the power switching system, you can switch the power supply using the conventional phase difference, that is, ±20°. This caused problems such as damage to the generator because the emergency synchronization was the same as when the generator breaker was turned on beyond the allowable phase range of the generator.

[Purpose of the invention] The present invention includes a private power generator that utilizes heat of vaporization.

When switching the on-site power supply system at a gas facility that receives power from two lines from different systems, the allowable phase difference between the power sources is automatically changed depending on whether the in-house generator is connected in parallel to the on-site power system. An object of the present invention is to provide an in-station power supply switching control device that can smoothly switch the power supply.

[Summary of the Invention] In order to achieve this object, the present invention uses a synchronization detection device in which the setting range of phase difference check can be changed by an external signal, and detects when one generator is connected in parallel to the power supply system. checks the phase difference allowed by the generator, and if it is within that range, it issues a permission signal to the power switching circuit, and if it exceeds the generator's tolerance, it locks the power switching circuit.

Alarm signal 1 Outputs a generator breaker open signal, then inputs a signal indicating that the generator breaker is disconnected to the synchronization detection device,
The feature is that the setting is changed to a phase difference check range that allows switching of the station power supply, and if the phase difference is within the setting range, a permission signal is output to the station power supply switching circuit to smoothly switch the station power supply. There is.

[Embodiments of the invention] The present invention will be described below with reference to the drawings.

FIG. 1 is an in-house power supply system diagram that includes power generation equipment attached to gas generation equipment at a gas facility. It has a No. 1 in-house transformer 1 and a No. 2 in-house transformer 2. Normally, the No. 1 power transmission @ No. 3 and No. 2 power transmission lines 5 are passed through the No. 1 transmission line breaker 4 and the No. 2 transmission line breaker 6, respectively. Power is received on No. 1 bus 7 and No. 2 bus 8. Power is received from each bus to the station transformer by the No. 1 transformer primary breaker 9 and the No. 2 transformer primary breaker 10, and the No. 1 in-plant metacla bus 11 receives power from the No. 1 in-plant metacla power receiving breaker 1.
2, and the No. 2 in-plant Metakura bus 13 receives power from the No. 2 in-plant Metakura power reception breaker 14, and each load Mn
supplied to As described above, the No. 1 side and the No. 2 side are usually configured with independent power sources, which supply power to the gas generation equipment. When the No. 1 power transmission line 3 is out of service, power from the No. 2 power transmission line 5 is supplied to the No. 1 side through the busbar communication breaker 16. Furthermore, when the No. 1 bus 7 or the No. 1 transformer 1 is out of service, the metallurgical bus line connection breaker 17 is turned on, and the power from the No. 2 transformer 2 is supplied to the No. 1 in-plant metallurgical bus 11.

When the cold power generator 1B attached to the gas generation equipment is connected to the metaclave bus 13 in the No. 2 plant via the generator breaker 19, the No. 1 transformer 1 is stopped and the power source of the No. 2 transformer 2 is turned off. When supplying to the Metakura Bus Line 11 in the station, the PT secondary voltage 20 of the Metakura Bus Line 1 and the secondary voltage 21 of the Metakura Bus Line 2 are input to the synchronization detection device 23 by a person at the synchronous operation switch 22 of the Metakura Bus Connection Breaker. However, if the phase difference is within the specified value, the synchronization detection device 23 outputs a closing permission signal 24 to the metal cluster bus line connection breaker 17. Then, a judgment signal 25 indicating that the cold power generator 18 is parallel to either of the power sources whose phase difference is being checked is input to the synchronization detection device 23, and the range of phase difference checking is switched in the synchronization detection device 23. . When the cold power generator 18 is connected in parallel to the power supply whose phase difference is being checked, the determination is made within the range of the phase difference allowed by the cold power generator 18, and if it is within that range, the metal cluster bus line connection breaker 17 is activated. Outputs the input permission signal 24, and if the phase difference exceeds the allowable range of the cold power generator, the Metacla bus line connection breaker 17
The input permission signal 24 is locked.

In addition, based on the negative signal of the judgment signal 25 indicating that the cold power generation @till is parallel to either of the power supplies for which one phase difference is being checked, the range of phase difference that is allowed by switching the station power supply is determined, and the range is determined. If so, a closing permission signal 24 is output to the Metacla bus line connection breaker 17.

Even if the phase difference exceeds the allowable phase difference when switching on-site power supplies, it is possible to output alarms, etc.

Next, the operation of the station power supply switching control device of the present invention will be explained with reference to the control flow diagram of FIG. 2.

PT2 of the two power supplies that synchronizes the synchronization detection device 1123 by human operation 26 of the synchronous operation switch of the breaker.
The next voltage will be the voltage. The synchronization detection device 23 receives the YES signal from the judgment 27 to determine whether the cold generator is paralleled to either of the power supply systems, and performs operation 2B to set the 1st phase difference check to X=±5°, and sets the 1st phase difference setting value. Judgment unit for determining whether it is within 2
Make a determination in step 9. If YES, output the power supply switching permission signal 30 and perform the breaker closing operation 3.
1 is performed, and the synchronous operation switch operation 3 of the breaker concerned is performed.
2 ends. After setting the phase difference check to X=±5° 28, if the determination unit 29 determines whether the phase difference is within the set value as NO, the power switch lock, alarm, and operation between the generator breaker are performed. Since the signal indicating that the generator breaker is open returns to the judgment 27 as to whether the J generator is paralleled to either of the relevant power supply systems and becomes a NO judgment, the synchronization detection device 2
3, the phase difference check is performed by setting operation 33 to x=±20°, and the determination unit 29 determines whether the phase difference is within the set value;
If YES, it power supply switching relevant cut-off permission signal 30
4 Phase difference check to output X = ±206 When the determination section 29 determines whether the phase difference is within the set value in operation 33 as No, it is possible to output an alarm, etc.
Inform the operator that synchronous power switching is not possible.

For manual switching of synchronous power sources, the circuit breaker that connects the two power sources usually has a synchronous operation switch, and the synchronous detection device is utilized more than the operator's operation. The synchronization detection device is also used.

For this reason, by applying the flowchart in Figure 2 to the breaker and the synchronous operation switch of the breaker when switching the power supply,
In addition, the determination 27 of whether a generator is parallel to either of the power supply systems can be adopted for power switching in other cases by configuring the breaker contacts in the system as a combined interlock condition. , it can be operated in exactly the same way as the conventional synchronous power supply switching operation.

[Effects of the Invention] As described above, according to the present invention, when a generator is connected in parallel to either of the power supply systems and the phase difference exceeds the allowable range of the generator, the generator breaker is activated. By increasing the allowable range of one phase difference by opening automatically or at the operator's discretion using an alarm, the danger of damaging the generator can be avoided without breaking the conventional operating method procedure, and the operation can be smoothly performed. It is possible to switch the power supply within the station,
This can greatly contribute to the switching of on-site power sources that have generators attached to gas generation equipment such as LNG terminals, which has been increasing in recent years.

[Brief explanation of the drawing]

FIG. 1 is an in-house power supply system diagram having power generation equipment attached to gas generation equipment in a gas facility, and FIG. 2 is a control flow diagram of the present invention. 1... No. 1 in-house transformer, 2... No. 2 in-house transformer, 3
... No. 1 transmission line, 4... No. - transmission line breaker, 5.
... No. 2 transmission line, 6 ... No. 2 transmission line breaker, 7...
・No. 1 bus bar, 8... No. 2 bus bar, 9... No. 1 transformer 1
Next breaker, 10... No. 2 transformer secondary breaker, 11
...Metakura bus line in the No. 1 plant, 12...Metakura power receiving breaker in the No. 1 plant, 13...Metakura bus bar in the No. 2 plant,
14...Metakura power receiving breaker in No. 2 plant, 16...
Busbar connection breaker, 17...Metakura busbar connection breaker, 18...Cold heat generator, 19...Generator breaker, 20...Metakura bus line PT secondary voltage in No. 1 plant, 21
...Secondary voltage of Metacla bus line connection in 2nd place, 22...
Synchronous operation switch, 23...Synchronization detection device, 24...
- Entry permission signal. (7317) Agent: Patent Attorney Noriyuki Chika (
(and 1 other person) Figure 1 Figure 2 Scrap

Claims (1)

[Claims] In a synchronous power switching circuit for an in-house power supply system that has a generator associated with gas generation equipment, the opening/closing conditions of the circuit breakers that make up the system, the on/off conditions for the synchronous operation switch of the breaker at the time of power switching, and the phase difference. Equipped with a synchronous detection device that allows the setting range of the check to be changed according to external conditions and an in-house power supply switching circuit, and when the power supply system is connected to a generator attached to the gas generation equipment in parallel during manual power switching, synchronous detection is performed. The device's phase difference check range is checked with the phase difference allowed by the generator, and if it is within the generator's allowable range, a permissible signal is sent to the station power supply switching circuit, and if it exceeds the generator's allowable range, the station It has an output signal that locks the power supply switching and opens the alarm and generator breaker, and if the generator is not connected in parallel to the relevant power supply system for on-site power switching, the range of phase difference check of the synchronization detection device is limited to the on-site power supply. The phase difference is checked by switching to an allowable value, and if the phase difference is within the allowable range for switching the station power supply, a permission signal is issued to the switching circuit for the station power supply.
An in-station power supply switching control device characterized by locking the in-station power supply switching and outputting an alarm if the range exceeds an allowable range in the in-station power supply switching.