JPS61177125A - Power source switchgear - 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] [Industrial Application Field] The present invention relates to a power switching device in power receiving equipment that receives power from a plurality of power sources. [Prior Art] Fig. 2 shows a conventional power switching device of this type. It is something that In the figure, IA is an A-system AC power supply (common power supply), and rB is a B-system AC power supply (standby power supply). 2A
, 2B is a power receiving breaker, 3A and 3B are busbars, 4 is a busbar connection breaker, 5 is a load breaker group, 6 is a motor group that is a load, 7A and 7B are instrument transformers, and the eye is a phase difference detector. It is.

Next, the operation of this device will be explained.

Now, the busbar connection breaker 4 is open, the power receiving breaker 2A is closed, and the busbar 3A is receiving power from the commercial power supply IA.
It is assumed that electric motor group 6 is supplied with power via load breaker 5 .

In this state, if an abnormality occurs in the regular power supply IA, for example, a power outage occurs, a power supply abnormality detection protective relay (not shown) is activated, the power reception breaker 2A is opened, and the busbar communication breaker 4 is closed. In this case, until the abnormality occurs in the regular power supply IA and the busbar communication breaker 4 closes, the operating time of the protective relay for power abnormality detection (not shown) and the opening operating time of the power receiving breaker 2A are approximately 0.2 There is a time delay of about ~0.3 seconds, and during this time, a residual voltage is applied to the bus bar 3A due to the residual magnetic flux of the load motor group 6, but this decreases over time and a phase delay occurs. do. For this reason,
Since a voltage difference and a phase difference occur between the bus bar 3A and the bus bar 3B, the phase difference detector 11 detects whether or not this phase difference is within a specified range. The communication circuit breaker 4 is closed.

[Problem that the invention seeks to solve]

However, in this conventional device, if the phase of the residual voltage attenuates quickly, the phase difference between the busbars 3A and 3B becomes larger than the specified range of the phase difference detector 11, and there is no opportunity to close the busbar communication breaker 4. Lost. If the load communication breaker 4 is turned on when the phase difference between the buses 3A and 3B is larger than the above specified range of the phase difference detector 11, an excessive current flows through the motor and the power transformer (not shown), giving a shock to them. In such a case, the residual voltage of the motor is almost attenuated, the load is disconnected from the bus 3A, and the bus connection breaker 4 is closed.
After that, loads are sequentially applied to the bus 3A, so a power outage of about several seconds occurs. For this reason, there is a problem in that when a load group requires uninterrupted power outage, countermeasures against power outage are required.

This invention was made to eliminate the above-mentioned problems, and an object of the present invention is to provide a power supply switching device that switches power supply uninterruptedly and without shock.

[Means to solve the problem]

In order to achieve the above object, the present invention connects a flywheel energy storage device to a bus on the power supply side, and when the flywheel energy storage device releases energy, the output frequency of the device is transferred between the bus on the power supply side and the bus on the standby power supply side. The adjustment is made according to the phase difference between the two.

[Effect]

In this invention, even if an abnormality occurs in the regular power source, power is supplied to the regular power source bus from the flywheel energy storage device without spring heating, and the frequency of this supplied power is adjusted to the frequency of the backup power source, so there is no power outage. Moreover, shockless power supply switching is realized.

〔Example〕

FIG. 1 is a block diagram showing one embodiment of the present invention.

In the figure, 9 is a flywheel energy storage device, which has a frequency control device and is connected to the bus bar 3A via a breaker 8. Reference numeral 10 is a frequency setting device, and the voltages of the busbars 3A and 3B are respectively set by the voltage transformer 7A.
, 7B, detects the phase difference between the two mold pressures, and creates a frequency command signal corresponding to the phase difference. This frequency command signal is fed to the frequency control device of the flywheel energy storage device 9.

In this configuration, the busbar connection breaker 4 is open, the power reception breaker 2A is closed, the busbar 3A is receiving power from the commercial power supply IA, and the motor load group 6 is supplied with power via the load breaker 5. During normal operation, the flywheel energy storage device 9 is driven by the AC power source IA and stores energy.

In this state, the AC power supply IA has a power outage and the power receiving breaker 2A
is opened, and at the same time the flywheel energy storage device 9 begins to release energy, supplying power to the busbar 3A. For this reason, a drop in the voltage of the bus bar 3A is prevented,
On the other hand, at the same time as the power reception breaker 2A is opened, the frequency control device of the flywheel energy storage device 9 receives a frequency command signal from the frequency setter 10 and adjusts the frequency of the voltage supplied by the flywheel energy storage device 9. Therefore, expansion of the phase difference between the voltage of the bus 3A and the voltage of the bus 3B is prevented, and the phase difference detector 11 detects the difference between the voltages of the bus 3A and 3B.
The busbar connection breaker 4 is closed by detecting zero phase difference between the voltages.

In this embodiment, since the output frequency of the flywheel energy storage device is adjusted, power switching is performed uninterrupted and without shock. However, if the shock at the time of switching can be ignored, the frequency setting device 10 can be used. There is no need to provide
Even in this case, uninterruptible switching is achieved.

Although the above embodiment describes the case where the regular power source and the standby power source are switched, the present invention can be implemented in the same manner as long as it has a power source configuration in which two or more power sources are switched and connected by a switching device. effect can be obtained.

Furthermore, in this embodiment, the load group and the flywheel energy storage device are connected only to the bus of the regular power source, but the load group and the flywheel energy storage device may also be connected to the bus of the standby power source. .

〔Effect of the invention〕

As explained above, the present invention is capable of realizing uninterruptible switching by connecting a flywheel energy device to a busbar, and also adjusts the output frequency of the flywheel energy device when releasing energy in accordance with the phase difference. Since the adjustment is made, it is possible to realize shortcutless switching.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIG. 2 is a circuit diagram of a conventional power supply switching device. In the figure, IA - regular power supply, IB - standby power supply, 3A,
3B-busbar, 4-busbar communication breaker, 6-motor group,
9-Flywheel energy storage device, 10-Frequency setter, 11-Phase difference detector. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] It has a switching device that switches between the busbars that are pressurized from the regular power supply and the busbars that are pressurized from the standby power supply, and a phase difference detector that detects the phase difference between the voltages of the two busbars. In a power supply switching device that switches and controls the switching switchgear when the phase difference is within a predetermined range, a flywheel energy storage device having a frequency control device is connected to a busbar pressurized from the commercial power source, and A power source characterized in that a frequency setter is provided for detecting a phase difference between bus voltages and generating a frequency command signal corresponding to the phase difference, and the output frequency of the flywheel energy storage device is controlled by the frequency command signal. Switching device.