JPS61135341A - Centralized load control system for transmission/distribution system - 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] [Field of Industrial Application] The present invention relates to a load control method in a power transmission and distribution system, and in particular, a method for centrally controlling a load by superimposing and transmitting an audio frequency voltage control signal in parallel with the load. Regarding the method of

[Conventional technology]

In general, power transmission and distribution systems can be broadly classified into upper power systems and controlled power systems. In this controlled power system, a phase advancing capacitor (C0) and a current limiting reactor (L,) are installed near the installation location of the main transformer. Further, a transmitting device is connected via a coupling device to the vicinity of the main transformer installation location of the controlled power system. On the other hand, a receiving device is connected to the power source terminals of load devices to be controlled (for example, electric water heaters, etc.) scattered in a controlled power system.

The transmitting device transmits an audio frequency control signal, and the transmitted control signal is received by the receiving device to control the load. Conventionally, a transmitting/receiving device transmits only a single audio frequency (for example, fI), and a receiving device also receives and decodes only this control signal (fl).

However, power transmission and distribution systems include phase advance capacitors or capacitive loads, and these capacitors and current limiting reactors or line inductances in the same system may cause series resonance. The resonant frequency and resonance point when this series resonance occurs is determined by the size and mounting position of the capacitor, current limiting reactor, and capacitive load, as well as the configuration of the power system and line inductance, and changes depending on the importance and increase or decrease of these factors. do.

In the conventional control system, in which a control signal of an audible frequency of a certain value is superimposed and injected in parallel with the load in the power transmission and distribution system to centrally control the load equipment, etc., the above-mentioned When a series resonance phenomenon exists and the resonant frequency matches or approximates the frequency of the control signal, the control signal is absorbed by the capacitor etc. and rapidly attenuates, causing the signal receiving device to malfunction. It had

[Problem that the invention seeks to solve]

An object of the present invention is to provide a load concentration control system for a power transmission and distribution system in which a signal receiving device does not malfunction even if a control signal is absorbed and attenuated due to a series resonance phenomenon within the system.

[Means for solving problems]

In order to solve the above problems, a transmitting device for superimposing and injecting voltage control signals of a plurality of audible frequencies and a signal receiving device for decoding one or more control signals are provided in parallel to a load in a power transmission and distribution system.

[For production]

A signal receiving device decodes one or more of the plurality of audio frequency voltage control signals emitted from the transmitting device, and controls the load based on the signals.

〔Example〕

Examples of the present invention will be described below.

FIG. 1 shows a system diagram of a load concentration control method in a power transmission and distribution system using multiple control signals according to the present invention.

In the figure, the power transmission and distribution system includes an upper power system in which the main transformer 10 is installed, a phase advance capacitor (CG) 20 installed near the installation location of the main transformer, and a current limiting reactor (
Lo ) 30 controlled power systems.

This phase advancing capacitor (C0) 20 and current limiting reactor (Lo
) 30 is determined by the following formula.

Furthermore, a transmitting device 40 is connected to the controlled power system via a coupling circuit near the installation location of the main transformer 10.

This transmitter 40 transmits control signals of a plurality of audio frequencies (for example, f+-'t, fs).

Note that the pulse code of each control signal is the same for each control purpose.

On the other hand, in the controlled power system, a phase advancing capacitor or capacitive load (C, ) 70, a line inductance (L, ) 50, and a line resistance (r, ) 60 are present on the line of the power transmission line. . The resonant frequency f between the phase advance capacitor (C1) and the line inductance (Ll) on this line can be found as follows. Note that L is the line inductance from the attachment point of the phase advance capacitor (C1) to the transmitter, and rl is the line resistance from the attachment point of the phase advance capacitor (C+) to the transmitter.

Further, a signal receiving device 80 is connected to the power supply terminals of load devices to be controlled (for example, electric water heaters, etc.) scattered in the controlled power system. This signal receiving device 80 is the transmitting device 40
Multiple audio frequencies (fs + f2, f
It has a filter that resonates at s. The signal receiving device 80 has a function of receiving and decoding one or more of the plurality of control signals and performing a predetermined operation. In this case, the resonant frequency fOefl
e't +f are all different values of audible frequencies as shown in FIG. Note that FIG. 2 shows the frequency characteristics of the drive impedance of the controlled power system at the end of the transmitter.

Therefore, according to this embodiment, the transmission and reception operations can be performed reliably regardless of the electrical characteristics of any system or how these characteristics change.

〔Effect of the invention〕

As explained above, according to the present invention, even if one control signal is absorbed and attenuated due to the series resonance phenomenon in the power transmission and distribution system, the signal receiving device can be operated accurately using other control signals. .

[Brief explanation of drawings]

FIG. 1 is a system diagram of a load heating control method in a power transmission and distribution system according to the present invention, and FIG. 2 is a frequency characteristic diagram of driving point impedance of a controlled power system at the end of a transmitter. 10... Main transformer 20... Phase advance capacitor 3
0... Current limiting reactor 40... Transmitting device 80...
・Signal receiving device

Claims (1)

[Claims] (1) In a device in which a phase advance capacitor and a current limiting reactor are connected to a main transformer, and power is supplied from the main transformer to a load, multiple frequencies are superimposed and injected into the load as control signals in parallel. A load centralized control method in a power transmission and distribution system, characterized in that a load is controlled by decoding one or more of control signals of a plurality of frequencies that are superimposed and injected.