Application of Low Voltage Intelligent Capacitors in JP Compensation Cabinets of Shandong Provincial Power Grid

1. Background introduction

In recent years, with the continuous deepening of urban and rural distribution network renovation, the demand for electricity consumption has been increasing. The normal operation of various power equipment requires the power supply system to have good stability and efficient power supply capacity. However, in the process of power supply in the power system, most of the electrical equipment belongs to inductive load equipment, which overall reduces the power of the power grid operation, increases the current reactive power, and causes a large amount of electrical energy loss. At the same time, it also affects the normal operation of equipment, accelerating equipment loss. To reduce the negative impact of reactive power, using JP compensation cabinets for power compensation in the power grid is an effective solution. The JP compensation cabinet is a common device for compensating power, and its core device is a low-voltage capacitor. The application of the JP compensation cabinet improves the overall operational efficiency of the power grid.

2. Existing problems

The traditional JP compensation cabinet mostly adopts the scheme of "miniature circuit breaker+capacitor switching switch+low-voltage capacitor". The capacitor branch is generally set to 1-6 channels, and the branch switching is coordinated and controlled by an external compensation controller. In practical applications, traditional capacitor switching switches are prone to generating surge currents during switching, which can have an impact on both the capacitor and the power grid, leading to a decrease in the lifespan of the capacitor and easy damage. At the same time, due to the use of a large number of discrete components in the capacitor compensation part, the JP compensation cabinet has a large volume, complex wiring, and difficult debugging; Moreover, due to the unique installation method and location, it is difficult to identify the cause of the malfunction and replace damaged components.

3. Reactive power compensation design

Regarding the transformer capacity of a supporting community in Shandong Province, the design capacity configuration of the JP compensation cabinet is as follows:

3.1 Product introduction

The SFR-L series low-voltage power capacitor modules are a new generation of reactive power compensation products aimed at 0.4KV low-voltage distribution systems, achieving efficient energy conservation, reducing line losses, improving power factor and power quality. This series of products is mainly used in situations where harmonic pollution is not severe.

This product is mainly composed of intelligent measurement and control units, thyristor composite switch circuits, high breaking capacity miniature circuit breakers, two △ type co compensating self-healing power capacitors or one Y-type sub compensating self-healing power capacitor, and a communication module that has been integrated into one through reasonable structural design to replace the traditional reactive power compensation method of power capacitors.

3.2 Design diagram - SFR-LXD

4. Project summary

The SFR-L series low-voltage intelligent capacitors have replaced the traditional reactive power compensation device composed of controllers, fuses, AC contactors, low-voltage capacitors, etc., changing the bulky and cumbersome structural mode of traditional reactive power compensation devices. This makes the new generation of low-voltage intelligent reactive power compensation devices have better compensation effects, lower power consumption, smaller size, more cost savings, more flexible use, more convenient maintenance, longer service life, and higher reliability, adapting to the higher requirements of modern power grids for reactive power compensation.

This series of products has been used in multiple box type distribution systems in Shandong Province, with reliable operation and good compensation effects, achieving the expected goals and improving the overall operational efficiency of the power grid. It has received unanimous praise from users.