Overview

Electric energy is the most widely used energy in modern society, and the quality of electric energy is related to all walks of life and people's electricity consumption, and is related to the overall benefit of the national economy. Scientific supervision of power quality is one of the necessary conditions for building a "conservation-oriented society". Power quality regulations and standards are the basic basis for ensuring power quality, and are the basis for implementing power quality supervision, ensuring product quality and the development of related industries, and safeguarding the legitimate rights and interests of both power and consumption parties. They are of great significance. With the development of modern economy and society, electrical equipment has become increasingly complex and diversified. A large number of application equipment with nonlinear, impact, unbalanced characteristic load and rich harmonics make a large number of harmonic and reactive power injected into the power grid, which greatly reduces the power quality of the power grid, causes grid pollution, and seriously affects the efficiency and reliability of the power supply grid. At the same time, a large number of new energy access to the grid, but also aggravated the above problems and hazards, power grid flexible technology, self-healing function needs more urgent, so the need for reactive power compensation and filtering harmonic governance and so on.

Existing problem

Reactive power undercompensation

Reactive power compensation reduces the user's own electricity expenses, ensures that the power factor meets the requirements of the power supply department, avoids the power rate electricity penalty, reduces the loss, reduces the voltage fluctuation, and improves the actual utilization of power generation equipment and power supply transformers.

Harmonic interference hazard

Harmonic control improves the quality of power supply, improves the reliability of equipment operation, and reduces the economic loss caused by equipment misoperation. Reduce the heat of the line, reduce insulation aging, improve the safety and reliability of electricity, reduce the resonant probability of compensation capacitors, improve the safety of electricity, reduce the electromagnetic interference caused by harmonics, ensure the normal operation of the communication system, meet the requirements of national standards.

Three-phase unbalance hazard

(1) Thoroughly solve the problem of three-phase imbalance in the distribution network, reduce the line loss of low-voltage distribution transformers and above the power grid, and improve the electricity sales revenue of the power supply company;

(2) Make reactive power reach local balance, improve the output of distribution transformer and equipment utilization rate;

(3) Improve the voltage quality in real time, stabilize the system voltage, improve the distribution quality, and improve the electricity environment;

(4) Perfectly solve the problems of transformer overload operation caused by three-phase imbalance and extend the life of the transformer.

Indirect benefits:

(1) Improve the power quality of regional low-voltage distribution network and greatly reduce the imbalance of distribution transformer outlet current;

(2) Reduce the faults and accidents caused by the negative sequence and zero sequence current caused by the unbalanced three-phase load in the distribution network, and improve the safety and reliability of the distribution system;

(3) Reduce the negative sequence and zero sequence current caused by the three-phase load imbalance in the distribution network, and extend the service life of distribution transformers, relay protection devices and power equipment.

Voltage fluctuation hazard

There are two kinds of voltage fluctuations. One is due to the fluctuation of the power grid, or the power grid load changes greatly cause the voltage to be high and low, for this situation can use a voltage regulator, there is an AC voltage regulator power supply, which can greatly reduce the degree of this fluctuation; Another kind of pressure drop caused by large load starting or running can be further optimized by soft starting and reactive power compensation devices.

3.3 Solution

Harmonic interference: parallel active filter device, intelligent hybrid filter compensation device, intelligent voltage regulation and power saving device

Reactive power undercompensation: traditional capacitor compensation cabinet, static reactive power generation device, intelligent hybrid filter compensation device

Three-phase imbalance: parallel active filter device, static reactive power generation device, intelligent voltage regulation and power saving device, voltage regulator