Method for controlling capacitance-split-type three-phase four-wire static synchronous compensator

Abstract

The invention relates to a method for controlling a capacitance-split-type three-phase four-wire static synchronous compensator. The method includes the steps that a fundamental wave active current component in a load current is detected, and voltage stabilizing control on a direct current side and voltage equalizing control on the direct current side are achieved on a voltage outer loop; the load current ILabc subtracts the fundamental wave positive sequence active current component ILfabc to obtain a tracking instruction of a current inner-loop double-loop controller, and the tracking instruction of the current inner-loop double-loop controller subtracts a current generated by the static synchronous compensator to obtain a deviation current; the deviation current is input into the current inner-loop double-loop controller, a system dynamic response speed is improved through an inner loop PI controller in the current inner-loop double-loop controller; the current tracking accuracy is improved through an outer loop repetitive controller in the current inner-loop double-loop controller. The current inner-loop double-loop controller achieves current control in the mode that the inner loop PI controller is embedded in the outer loop repetitive controller.

Description

technical field [0001] The invention relates to a static synchronous compensation control method in reactive power compensation of electric power quality in an electric power system, in particular to a control method of a capacitor-split three-phase four-wire static synchronous compensator. Background technique [0002] In recent years, with the rapid development of society, users have higher and higher requirements for power quality, and large-capacity impact asymmetric loads such as electric arc furnaces, rolling mills, and electrified railways in the distribution network have brought great impact on the power grid. Pollution, which will affect the normal and safe operation of electrical equipment. Static synchronous compensator, as an advanced reactive power compensation device with ideal performance, can effectively compensate reactive power and improve power quality. Compared with the traditional static var compensator (SVC), the static synchronous compensator has bett...

AI Technical Summary

Problems solved by technology

[0003] The reactive power compensation of the three-phase load asymmetrical system uses a relatively wide topology, phase-splitting structure and three-phase four-wire four-bridge arm structure, but this structure has many switching devices and the cost is too high. For small-capacity occasions, three Phase four-wire capacitor split structure, less hardware investment, low cost, and more commercial application value

However, most of the control methods currently used are mostly double-closed-loop control methods based on PI controllers. This method has a high dynamic response speed, but the bandwidth of the PI controller is limited, and it is difficult to track periodic signals such as reactive power and harmonics. Unsatisfactory performance, low steady-state accuracy

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