I. Overview

With the development of modern industrial technology, especially in the automobile manufacturing industry, there are many high-power spot welding machines. The power factor of spot welding machines is low, and it contains a large amount of reactive power and a small amount of harmonics, which has a negative impact on the operation of the power system.

Load characteristics of spot welding machine:

1. The action time of spot welding machine is extremely fast, the welding duration is hundreds of milliseconds, and the welding frequency is fast;

2. During the welding process of spot welding machine, according to the different welding materials, the welding current can reach severalamperes to thousands of amperes instantly, which has a great impact on the power grid;

3. During the welding process of spot welding machine, huge reactive power is produced, which leads to the power factor of the grid is very low.

II. Measurement data

Comparison of power grid data before and after SVG&LC is put into operation:

III. SFR series SVG combined with LC reactive power compensation function introduction

SVG combined with LC reactive power compensation is a new type of power electronic device for dynamic reactive power compensation. It can compensate the dynamic reactive power in real time, which can overcome the shortcomings of traditional LC reactive power compensation and realize reactive power compensation function. It is widely used in manufacturing, electric power, metallurgy, petroleum, port, chemical industry and mining enterprises, etc.

1. Quick response

Fast response is realized by SVG module, SVG fast response time <50us, full response time <15ms;

2. Good compensation characteristics

3. Good compensation effect

IV Design of SVG & LC reactive power compensation scheme

V Project summary

It completely and effectively solves the rapid change of reactive power compensation such as spot welding machines. The power factor at the incoming cabinet of each transformer meets the requirements of the national standard, which purifies the power environment, and ensures the safe and stable operation of the equipment. Greatly improves the effective utilization of electric energy; reduces the loss of distribution lines, increases the terminal voltage and prolongs the service life of cables and equipment.