STATCOM/SVG INTRODUCTION

Static Synchronous Compensator STATCOM (SVG) is one of the core equipment FACTS (Flexible Alternative Current Transmission Systems).The system can quickly compensate reactive, and take effective governance for harmonics, voltage fluctuations and flicker and other power quality problems, improve the safety and reliability of the system.

With the limits of the IGBT can withstand voltage level, current high voltage SVG/STATCOM module cascading is usually used as the main circuit topology, so require a separate power supply to drive IGBT for each module.

ZDDQ 10KV SVG/STATCOM
The 10kv svg structure of main circuit is shown following Fig.  used Y-connector, ungrounded, access 10kV bus way through LCL. Controller is controlled by the signal conditioning boards with FPGA/DSP plates to power through the fiber-optic module sends instructions or read the power module status. Power module consists of an h-bridge voltage source inverter and bypass, and bypass is used in case of inverter failure, short-circuit the output of the inverter, make chain of the inverter can still run properly, to achieve power redundancy module. Controller and power module provide DC power in the programs; the controller uses 24V power directly, the internal uses DC / DC circuits to generate the required voltage, e to implement easily. As the main circuit's neutral point ungrounded, power module housing may carry high voltage, direct current power supply part of the power module is required to have high voltage isolation.

ZDDQ MV/HV static var generator using IGBT as the core power modules which can quickly and continuously provide capacitive or inductive reactive power, achieve constant reactive power, constant voltage and constant power factor control through the assessment point, and ensure the power grid is running stable, high efficiency and high quality. In the power distribution network, the small capacity HVSVG can significantly improve the power quality (improve the power factor, overcome phase imbalance, eliminate voltage flicker and fluctuation, restraining harmonic), if it is installed in some special loads (such as electric arc furnace).

Features of HVSVG Products

◆Improve the stability of transmission line.

If HVSVG is installed in the long-distance transmission lines, it not only compensate the reactive power losses, raise the line voltage and improve the grid capacity when the system is normal, but also regulate the reactive power, improve grid stability when the system is failure.

◆Maintain the terminal voltage and enhance the voltage stability.

For the load center, due its load capacity is large and without reactive power devices, the grid voltage may be lower and even lead voltage collapse. HVSVG can maintain the load voltage and improve the stability of the load voltage, because of fast reactive power regulation ability.

◆Compensate reactive power, improve power factor, reducing line losses and saving energy.

Both the load of power system and transmission system itself need reactive power, which lead to lower the power factor.

For the power system, low power factor will increase the line losses and reduce voltage quality. The use efficiency of power generation, transmission and power supply equipment will be reduced. For the user, it will increase electricity costs.

◆Suppress voltage fluctuation and flicker.

When the load change dramatically, voltage fluctuation and flicker may occur. The dramatic change of load will lead to the dramatic change of load current. The changing current will lead to voltage loss. As result, the voltage flicker occurs. There are many loads may cause voltage flicker, such as electric arc furnace, rolling mill and electric locomotive.

HVSVG can change the active power current quickly to compensate the voltage fluctuation and flicker.

Currently, the best way to solve the voltage fluctuation and flicker is to use HVSVG.

◆Suppression of three phase imbalance.

For the distribution network, there are a lot of three-phase imbalanced loads and the typically loads are electric loco motives and AC electric arc furnace. The imbalance of three phase resistance of distribution equipment will lead voltage imbalance too.

HVSVG can quickly compensate the imbalance of loads, which makes sure the three-phase currents on the grid side is balance and improve the power quality.