Apparatus for effectively compensating three-phase unbalance load and reactive power

Abstract

The invention discloses a device for efficiently compensating three-phase unbalanced loads and reactive power, which includes: three-phase current and three-phase voltage sampling circuits of a three-phase power system, a power controller and different three-phase compensation unit. It is characterized in that the power controller controls each single-phase switch in the three-phase compensation unit with different topological structures separately according to the sampling results, so that it can realize both common compensation and single compensation; it can not only compensate reactive power, but also balance Active power; it can be used as both static compensation and dynamic compensation; it can not only adjust the ability of three-phase current, but also adjust the three-phase unbalanced voltage. The invention is suitable for the transformation and updating of the existing reactive power compensation device of the three-phase four-wire unbalanced load power system.

Description

technical field [0001] The invention relates to the field of three-phase power unbalance compensation and reactive power compensation of electric power system. Background technique [0002] Most of the existing technologies use three-phase Δ power capacitors (or composed of three single-phase power capacitors) and single-phase power capacitors to compensate the reactive power of the power system. Compensation device", the Chinese patent number is 00259313.0, the name is "a set of thyristor switching multi-channel capacitor compensation device", the Chinese patent number is 01239190.5, the name is "phase-separated and graded reactive power compensation control device", the Chinese patent number 01114333.9, titled "Dynamic Capacitor and Its Switching Method", Chinese Patent No. 98237745.2, titled "Efficient Phase Control Automatic Reactive Power Compensation Device", Chinese Patent No. 02256020.3, titled "Intelligent Phase Split Capacitor Compensation Power distribution devic...

AI Technical Summary

Problems solved by technology

[0002] Most of the existing technologies use three-phase Δ power capacitors (or composed of three single-phase power capacitors) and single-phase power capacitors to compensate the reactive power of the power system. Compensation device", the Chinese patent number is 00259313.0, the name is "a set of thyristor switching multi-channel capacitor compensation device", the Chinese patent number is 01239190.5, the name is "phase-separated and graded reactive power compensation control device", the Chinese patent number 01114333.9, titled "Dynamic Capacitor and Its Switching Method", Chinese Patent No. 98237745.2, titled "Efficient Phase Control Automatic Reactive Power Compensation Device", Chinese Patent No. 02256020.3, titled "Intelligent Phase Split Capacitor Compensation Power distribution device", the application number is 03133841.0, the name is "fast-tracking low-voltage reactive power compensation device", the application number is 86102657, the name is "reactive power automatic compensation control method and compensation system", the application number is 88220752.0, the name is "Dynamic power factor compensation device", the application number is 00100589.8, the name is "automatic non-contact switching reactive power compensation device", the application number is 02139174.2, the name is "dynamic reactive power compensation method and device", etc., these methods Although the sum device can compensate reactive power, it cannot balance active power. When the three-phase active power of the power system is unbalanced, even if the delta-connected capacitor bank composed of expensive single-phase power capacitors is used, it will be converted into a Y-connected capacitor through a cumbersome circuit. The method of the group cannot solve the problem of balancing active power

[0003] Although there is a method that can both adjust the three-phase unbalanced current and compensate reactive power at the same time (the patent number is 00110110.2, the name is "power factor compensation device that can correct three-phase unbalanced current), but in this scheme all adopt Most of them are single-phase capacitors, which are not only costly, but also difficult to meet the technical transformation requirements of many reactive power compensation devices composed of three-phase Δ-connected power capacitors; at the same time, due to the use of too many switches to control the switching , so the changeover switch only uses a contact switch with a lower price. Otherwise, if a non-contact switch or a composite switch is used, the cost of the device will reach an unacceptable level in the market, which will greatly improve the dynamic response speed of the device. A great limit, it is difficult to achieve dynamic compensation

Therefore, it is difficult to fully promote the program

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