Composite compensation device for long-distance sparse power supply

Abstract

The invention provides a composite compensation device for long-distance sparse power supply. The input is a power supply line input end, and the output is a power supply line output end. The device comprises a voltage boosting system and an electric energy quality boosting system, wherein the voltage boosting system comprises a voltage boosting compensation transformer, a voltage boosting power electronic converter and a voltage boosting control unit; and the electric energy quality boosting system comprises a contactor, an electric energy quality boosting compensation transformer, an electric energy quality boosting power electronic converter and an electric energy quality boosting control unit. According to the invention, the power electronic converter and the compensation transformer are used for injecting a current and a voltage into a power grid and performing real-time control, thereby achieving the comprehensive power quality improvement of power harmonic waves, power factors, three-phase imbalance compensation and the like and the voltage compensation function of a sparse power utilization area of a long power transmission line. The device has important significance on power supply radius extension, investment saving and power grid safety of the sparse power utilization area.

Description

technical field [0001] The invention belongs to a circuit device or system for power supply or distribution, in particular to a compensation device or system for an AC transmission line or an AC power distribution network. Background technique [0002] The western region of my country has a vast territory, low population density, and sparse power consumption. Using the traditional method to build new substations on the extended power supply lines requires a large construction investment and poor economic benefits. Therefore, it is necessary to consider extending the power supply radius to achieve long-distance power supply. However, long-distance power supply will bring large line power loss and voltage drop. For example, when the line of the 10kV distribution network exceeds 200km, the line power loss is as high as 30% and the power supply voltage drops by more than 50%. In addition, the power grid in sparse areas Technology, there are many other challenges, such as power q...

AI Technical Summary

Problems solved by technology

However, long-distance power supply will bring large line power loss and voltage drop. For example, when the line of the 10kV distribution network exceeds 200km, the line power loss is as high as 30% and the power supply voltage drops by more than 50%. In addition, the power grid in sparse areas There are many other challenges, such as power quality problems: the power consumption along the route is mainly non-industrial loads, the distribution of personnel and the difference in power consumption lead to three-phase imbalance, and the variety of electrical equipment leads to increased harmonics and reduced power factor, etc.

However, these devices have their own defects and cannot be applied to improve the power quality of long-distance transmission lines in the west

For example, the passive compensation device uses capacitors, inductors and other devices, and the device is relatively large; for example, the static var compensator can be adjusted smoothly and has a fast response speed, which is an ideal reactive power source. However, this The design of the device system is complicated, the compensation is complicated, the cost of the device is high, and the requirements for operation and maintenance are high, so it cannot be popularized and applied in a large area

For another example, the parallel capacitor reactive power compensation device cannot be continuously adjusted, and the load adjustment characteristics are poor. It will amplify the high-order harmonics in the system. When the harmonic current is too large, it may cause an explosion, and the switching process will produce Severe operating overvoltage and closing inrush, these transient processes often become the cause of system failure, affect the reliability of power supply, and thus cannot fully meet the special requirements for solving power quality problems at the end of long-distance transmission lines in the power grid

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