JPS5917825A - Bus communication controller - 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 Technical Field of the Invention The present invention relates to power supply equipment installed in an electric station.Technical background of the invention and its problems In recent years, liquefaction has been used as a fuel source in thermal power plants or as a fuel source for general household use. Natural gas (hereinafter simply referred to as LNG)
is becoming more and more popular.

LNG is transported as an ultra-low temperature liquid from its place of origin, gasified by heating with seawater, and supplied as fuel for thermal power generation or general household use. In order to gasify the transported liquid as mentioned above, tanks and motors are required.

Various mechanical equipment such as pumps are required, and power supply equipment is also required as a power source for the equipment. On the other hand, as a recent technological achievement, a cold energy power generation method that takes advantage of the ultra-low temperature of liquid has emerged. Figure 1 shows an LNG generator equipped with an LNG generator.
An example of a power supply system diagram of NG power supply equipment is shown.

Power is supplied from the power transmission line IA, and is supplied to the high voltage bus 4A via the #L source transformer 2A and the power reception breaker 3A. A power transformer 7A for supplying a motor 5A1 and a low voltage load 6AK is connected to the high voltage bus 4A via circuit breakers 8A and 9A. Similarly, power is supplied from the power transmission [113, vl
It has the other system configuration of the t-source transformer 2B. The connection breaker 10 that connects the high voltage buses 4A and 48 is connected to the power transformer 2 of either the high voltage buses 4A or 4B.
When it becomes impossible to receive power supply due to a failure of a person or 2B, this communication breaker IO is installed so that power can be supplied from the healthy side by turning on the breaker IO.

In normal operating conditions, the high voltage buses 4A and 4B are supplied from their respective power transformers 2A and 2B, supplying power to various equipment, and functioning as LN (11 Jt source equipment).In this state, 1. When the NG generator 11 is also able to generate electricity, it starts supplying power by turning on the circuit breaker 12.However, compared to the two power transformers, its generation filter is small and it is difficult to cover the entire load of the high voltage bus 4A. Since there is no traffic, the power line is operated in parallel with the power line LA in order to reduce the power supply from one person, albeit slightly.

In the power supply system as described above, the power transmission line IA or 113,
Power transformer 2Aj! If it becomes necessary to suspend 2B due to an abnormality or periodic inspection, power to the high voltage bus 4A or 4B on the suspended side must be secured by turning on the communication breaker IO.

As a condition for turning on the connection breaker 10, it is necessary to satisfy the synchronization conditions between both shore lines, but the conditions for synchronization between the cold generator 11 and the motor 5A are different, and the conditions for the cold generator 11 are stricter. . In addition, the phase difference between the power transmission lines IA and I8 is not always constant, so if the synchronization condition is set to one shift that satisfies the cold-heat generator 11, synchronized switching may not be possible. In addition, under the synchronization conditions that satisfy the motor 5A, there is a risk that the cold generator 11 will be damaged due to abnormal torque at the time of switching.

Purpose of the Invention The present invention was made in view of the above points, and it is an object of the present invention to confirm the phase difference between the two systems, continue a stable supply of rIL, and operate the launch site safely and efficiently. With the goal.

Summary of the Invention The present invention relates to a busbar communication control device in a system configuration in which a high voltage bus to which a generator is connected is connected to another control bus via a busbar communication breaker. Prepare at least two JB commands to close the busbar communication breaker when it is within the first setting value, and to turn on the bus line breaker when it is above the first setting value.
If the voltage is below a set value, the generator is disconnected from the high-voltage bus, and then the bus is connected or a disconnector is turned on.

EXAMPLES OF THE INVENTION A detailed review of the examples will be described below. FIG. 2 shows an example of a control block diagram in the present invention. In FIG. 2, the bus switching signal 13 when switching the bus, and the phase difference confirmation relay 14 when switching the bus, are the signals 15 that turn on at or below the α setting.
and β setting is 1 and ON 1 has No. 16. Signal 17 indicates a trip signal to cut off the power reception of the high voltage bus that is inactive, and No. 18 indicates a signal to turn on the bus connection breaker.
Signal 19I'1 indicates a trip signal to the LNG breaker.

The operation will be explained below. When bus line switching (No. g) 3 occurs, the phase difference between the lines on both banks at that time is checked with the phase difference confirmation relay 14, and if it is less than the α setting, (.

The AND of Nos. 13 and 15 is established, a trip signal 17 to the receiver/receiver breaker is generated, and the receiver/receiver breaker turns OFF.
When the power reception breaker OFF signal is applied and the No. 16 170 ceramic ram is turned on, the busbar connection breaker is turned on. The α setting of this anastomosis satisfies the synchronization condition for one LNG generator,
Enables continuous operation of LNG generators. Also, if the phase difference is higher than the α setting and lower than the β setting when checking the phase difference, a trip signal 19 to interrupt the LNG generator generator is issued, and the LNG generator breaker, OFF signal 21 turns off the power receiving breaker.
, the busbar connection breaker is turned ON, and the busbar switching is completed. The β setting in this case satisfies the synchronization condition of the motor connected to the high voltage bus, and the relationship β>α holds.

As described in the detailed description of the invention, the phase difference is checked at the time of bus switching, and if it is within the allowable value for one generator, the switching is performed while the generator continues to operate, thereby preventing unnecessary generator stops. , when the generator exceeds the allowable value, the busbar is switched with emphasis on stable power supply as a power supply facility.

Although the present invention describes the case where an LNG generator is connected to the high-voltage bus, the same can be said about the case where other generators such as diesel generators are connected.

Furthermore, it goes without saying that the phase difference and confirmation relay can be configured with two confirmation relays with one setting instead of a two-setting confirmation relay.

[Brief explanation of drawings]

FIG. 1 is a power supply system diagram of the LNGi source equipment, and FIG. 2 is a control program diagram in the present invention. IA, IB...Send l+1 12...Break 2A, 2B...Power transformer 13...Bus bar switching signal 3A, 3B...Power receiving breaker 14...Phase difference confirmation relay 4A, 4B ...High voltage bus bar 15...ON signal below α setting 5A, 5B...Motor 16.
...β 〃6A, 6B...Low pressure load 17...
- Breaker trip signals 7A, 7B... Power transformer 18... Closing signal 10... Connection breaker 11... 1. NG Generator (7317) Agent Patent Attorney Noriyuki Henyu (1 idiot) 1st
Figure 2

Claims (1)

[Claims] In a system configuration in which a high voltage bus to which a generator is connected is connected to another high voltage bus through a bus connection breaker, prepare at least two setting values for the phase difference confirmation relay when connecting the bus, and ensure that the setting value is within the first setting value. The system is characterized in that a command is given to close the busbar communication breaker, and when the voltage is greater than or equal to the first set value and less than the second setpoint, the generator is disconnected from the high voltage bus and then the busbar communication breaker is closed. Busbar communication control device.