JPS6253123A - Load selection breaker - 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 a load selection and cutoff device that performs appropriate load selection and cutoff using an arithmetic device such as an electronic computer.

[Technical background of the invention and its problems] FIG. 3 shows an example of a general configuration of a power system in which selective load cutoff is performed.

In FIG. 3, reference numeral 1 denotes a power supply facility of an electric power company consisting of a power generation unit 1i1G and a sectional breaker 2, and the power is supplied to a load via a power receiving breaker 4 of a power receiving and distribution facility 3 of a consumer.

On the other hand, the power receiving and distributing equipment 3 includes a private generator 11 5, and the generated illumination power is supplied via a circuit breaker 6, and power purchased from an electric power company and privately generated power are always supplied in parallel.

Further, the power receiving and distribution equipment 3 includes circuit breakers 7-1 to 7-n for supplying power to loads L1 to L1-n.

In such a power system, when a fault such as a short circuit or ground fault occurs in the power transmission section between the power supply equipment 1 of the power company and the power receiving and distribution equipment 3 of the consumer, the fault detection relay operates and the power receiving breaker of the consumer is activated. 4, and each load on the power receiving and distribution equipment 3 is covered only by the private generator 5.

Generally, the load capacity of the private generator 5 is larger than the capacity of the private generator 5, so the private generator 5 becomes overloaded, and the breaker 6 is tripped, resulting in a total power outage of the power receiving and distribution equipment 3.

In order to avoid this, a PAn device such as a computer is used to selectively cut off the load, and the power is supplied only to m load units corresponding to the capacity of the private generator.

Therefore, the receiving arrangement iIQ 3 is a power converter 8.9°10
-1 to 10-n are used to detect the power of each part.

An example of a conventional load selective cutoff at 5A is shown in FIG.

In FIG. 4, reference numeral 11 denotes a sampling execution control device, which outputs a sampling signal @a with a constant period Ta, thereby controlling the analog data numbering device 12 and converting the power supplied from the power converters 8 and 9 to ps. , load power consumption P1 from PG and power converters 10-1 to 10-n
~pn is read and sent to the arithmetic unit 13 as sampling data.

The arithmetic unit 13 calculates the selected cutoff power sampling data P8 based on these sampling data, and selects the cutoff power sampling data P8. 7i power is determined, a cutoff feeder is determined based on the priority order stored in the digital data memory 14 by external setting, and a load selection signal is outputted via the selected cutoff feeder set output device 15.

This selection signal is a selective cutoff feeder set output device! 11
5 holds the same set contents unless there is a new input.

The process from sampling to selected output is managed by sampling execution control @[11.

However, such a conventional load selection breaker device 1
6, sampling is performed every fixed period Ta as shown in FIG.
Since a is relatively long, the load is selected based on the calculation result after sampling is completed. If a state change (for example, ON-+0FF) occurs in the breaker of the breaker feeder, the power balance will be disrupted and a shortage of breaker will occur. As a result, there was a risk that the power receiving and distribution equipment 3 would experience a total power outage.

FIG. 5 is a time chart showing the above phenomenon, and (a
) are sampling signals A, B, C, ..., (b) are supply power sampling data Wa - (Ps + PG) read every sampling period Ta, (C") are load consumption read every sampling period Ta Sampling data WL, (d) is selected cutting power sampling data Wsx calculated based on the difference between supplied power sampling data WG and load consumption sampling data WL, (e) is set output cover turn of load selection cutting feeder, (f) indicates the timing at which the state change of the breaker set in the load selection breaker feeder occurs.

Here, the numbering signals A, B, C, . . . are output from the sampling execution control table [11], and the analog data sampling device 12 executes sampling based on these signals.

Therefore, the selected cutting-off power Ws is calculated based on the difference between the supplied power WG sampled at timing A and the load consumption power WL, and the selected shear-cutting feeder set pattern A' is determined.

Further, the selected cutoff feeder set pattern is not updated until the next timing B.

For this reason, the breaker of each feeder is set to 8 from timing A.
If a state change (for example, ON-OFF) occurs during this period, the strength of the selected cutoff set pattern A' will become excessive, and the load will be cut off more than necessary.

On the other hand, if a 0FF-ON change occurs, there will be a shortage of circuit breakers, leading to an overload of the private generator 5 shown in FIG.

[Object of the invention] The present invention performs sampling in addition to regular sampling at a constant period, and also performs sampling when the state of the circuit breaker changes.
The purpose of this invention is to provide a rational load selection cutoff device that always maintains a balance between supply power and load power.

[Summary of the Invention] The present invention operates a plurality of power supplies in parallel to sample the power amount of the power supply and load of a power system that supplies power to a plurality of loads at a constant frequency If, In a load selection breaker that selects and cuts off a part of the load so that the load power is balanced with the capacity of the remaining power supply by calculating sampling data when one of the power supplies loses power, detects changes in the open/closed state of the load breaker. A state change detection circuit is provided, and sampling is performed in addition to the constant cycle sampling for each state change, thereby ensuring that the supply power and the load power are always balanced.

[Embodiments of the invention] An embodiment of the present invention is shown in FIG.

Compared to the conventional FIG. 4, FIG. 1 has an additional digital data detection device 17 that detects the state of the load breaker, and its output is input to the sampling execution control device 11 and the arithmetic device 13, and the power data is sampled. The other operations are the same as the conventional one shown in FIG. 4, except for the execution of the arithmetic program and the selection and selection of feeders.

Next, the present invention will be explained in detail using the time chart shown in FIG.

A selected cutoff feeder set pattern A' is selected based on the selected cutoff power Ws calculated at timing A,
If there is a change in the state of the breaker of the selected cutoff load (for example from ON to 0FF) at the station up to the next timing B, the digital data detection device 17 detects this and sets a time delay Tb to avoid the transient power change. At timing A1 after the time interval, an execution signal is given to the sampling execution control device W111 to sample the supplied power WL, and a signal is also given to the arithmetic unit 13 to set the selective cutoff feeder set pattern A+'.

Therefore, the selective cutoff power Ws is always calculated based on the calculation results of the true supply power WG and the load power consumption WL, and even after load selection cutoff is performed by a fault disconnection signal, there is no shortage of power receiving and distribution equipment 3. can be operated safely without power outages.

In the above embodiment, a change in the state of the load breaker is detected, but it is also possible to use a control signal or a fault signal that causes a change in the state of the breaker.

[Effects of the Invention] As explained above, according to the present invention, even if a change in the state of the selectively cut-off load occurs, load selective cutoff is always performed based on the calculation result of sampling data of the true power of the power source and the load system. Therefore, it is possible to realize a rational load selection cutoff device that achieves the original purpose of load selection cutoff without causing a shortage of cutoff m.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the load selection cutoff device of the present invention, Fig. 2 is a time chart showing the operation of Fig. 1, and Fig. 3 is a general diagram of the power system to which the present invention is applied. FIG. 4 is a block diagram showing an example of a conventional load selection cutoff device, and FIG. 5 is a time chart showing the operation of FIG. 4. G... Generator 11 ~ In... Load 1... Power supply equipment 2... Power supply side breaker 3... Power receiving and distribution equipment 4... Power receiving breaker 5... Private departure ff1lN 6. ...Private circuit breakers 7-1 to 7-n...Load circuit breakers 8, 9, 10-1 to 10-n...Power converter 1
1... Sampling execution control device 12... Analog data sampling device 13...
Arithmetic device 14...Digital data memory 15...Selective cutoff feeder set output device 1G...
・Load selection cutoff device 17...Digital data detection device Representative Patent attorney Nori Chika Ken Yudo Hiroshi Mitsumata Figure 3 Figure 4

Claims (1)

[Claims] The power supply and load power of a power system that supplies power to multiple loads by operating multiple power supplies in parallel is sampled at regular intervals, and the sampling data is calculated when any of the multiple power supplies fails. In a load selection breaker that selectively cuts off a part of the load so that the load amount is balanced with the capacity of the remaining power source, a state change detection circuit is provided to detect a change in the open/closed state of the load breaker, A load selective cutoff device characterized in that sampling is additionally performed in addition to the above-mentioned constant cycle sampling.