JPH1094162A - Demand monitor controller provided with higher harmonics measuring function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a demand monitor controller provided with a higher harnomics measuring function which can perform the management and monitor control of the use power of a customer with simple constitution. SOLUTION: A higher harmonics measuring part 1B is annexed to the demand monitor controller 1A which manages the use power of a customer. The higher harmonics measuring part 1B is provided with an alarm contact 1B1 for higher harmonics and a control output contact 1B2 . The alarm contact 1B1 and the control output contact 1B2 are operated when higher harmonics occurrence rate gets over a certain value so as to prevent the occurrence of the fault by higher harmonics of the electronic equipment or the power capacitor of a power distribution system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a demand monitoring control device for managing power consumption of a customer.

[0002]

2. Description of the Related Art A demand monitoring control device and a harmonic measurement device are used for monitoring control and measurement of a power distribution system. The demand monitoring and control device manages the power consumption of the customer and issues an alarm or load shedding output when the power consumption exceeds the basic power amount contracted between the customer and the power company to prevent an increase in the basic charge. It is. The harmonic measurement device measures a ratio of a harmonic current to a basic sine wave in an electric circuit for each order.

[0003]

In recent years, guidelines for harmonic suppression measures have been issued by the Electricity Association of Japan by the notification of the Ministry of International Trade and Industry, and it is necessary to manage harmonics at the receiving points of consumers.

However, in the measurement of harmonics, a method of connecting a test device to an electric circuit has been adopted.
At present, no measures are taken to protect the electronic devices and power capacitors in the system at the time of harmonic generation.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a compact structure for managing power consumption of a customer by providing a harmonic measurement function and providing an alarm and control output contact for harmonics. Another object of the present invention is to provide a demand monitoring control device with a harmonic measurement function capable of performing monitoring control accurately.

[0006]

According to the present invention, a function for managing the power consumption of a consumer, a function for measuring a ratio of harmonics contained in a current, and an operation when a harmonic generation rate is equal to or higher than a predetermined value are provided. The alarm and control output contacts for harmonics are provided, and it is possible to appropriately prevent failure of electronic devices and power capacitors due to harmonics.

[0007]

FIG. 1 shows an embodiment of the present invention. In this embodiment, the demand monitoring control device 1 is provided with a harmonic measurement function, and the demand monitoring control unit 1A and the harmonic measurement unit 1B are integrated. The harmonic measurement unit 1B, in addition to that provided alarm contact 1B ₁ and the control output contact 1B ₂ measurement functions.

The demand monitoring control unit 1A inputs the power used in the form of a pulse signal from the power measuring unit of the PCT (transformer for transformer) 2 and a PT (instrument) connected to the power supply side of the power receiving circuit breaker 3. And a current from a CT (current transformer) 5 connected to the load side. The voltage and current in these inputs are also input to the harmonic measurement unit 1B.

With this configuration, the power consumption of the customer is managed by the operation of the demand monitoring control unit 1A, and the harmonic generation rate is constantly measured by the harmonic measurement unit 1B. If the harmonic generation rate exceeds a predetermined value (set value), and harmonic for alarm contact 1B ₁ and the control output contact 1B ₂ operation (ON), with its effect of the alarm is issued, the protection operation This is done to isolate the electronics and power capacitors from the grid.

[0010]

As described above, according to the present invention, the alarm output and the control output are provided in the harmonic measuring section. Separate electronic devices and power capacitors from the grid,
Appropriate protection can be achieved. Moreover, it is possible to realize a compact configuration by integrating the harmonic measurement unit and the demand monitoring control unit.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

[Explanation of symbols]

1 ... demand monitoring control device 1A ... demand monitoring control unit 1B ... harmonic measuring unit 1B ₁ ... alarm contact 1B ₂ ... control output contacts 2 ... PCT 3 ... receiving breaker 4 ... PT 5 ... CT

Claims (1)

[Claims] 1. A function for managing power consumption of a customer, a function for measuring a ratio of harmonics included in a current, and a warning and control output for a harmonic that operates when a harmonic generation rate is equal to or higher than a certain value. A demand monitoring control device with a harmonic measurement control function, comprising: a contact;