Ultrahigh-order harmonic compensation control method

Abstract

The invention provides an ultra-high-order harmonic compensation control method, which is applied to an ultra-high-order harmonic compensation device, the device comprises an ultra-high-order harmonic source connected to a power grid, and the method comprises the following steps: S101, detecting ultra-high-order harmonics at a common connection point of the power grid, judging whether compensation is needed or not based on a detection result, if compensation is not needed, locking the ultra-high-order harmonic source, and if compensation is not needed, locking the ultra-high-order harmonic source; if compensation is needed, executing the next step; s102, determining a carrier angular frequency according to the detected ultra-high-order harmonics, and assigning initial values to a carrier phase, a direct current side voltage amplitude and a modulation ratio; s103, the carrier phase, the modulation ratio and the direct current side voltage amplitude are set until the carrier phase, the modulation ratio and the current side voltage amplitude which inhibit the ultra-high-order harmonic amplitude at the common connection point of the system side to the maximum degree are found; and S104, judging whether the ultra-high-order harmonic index at the common connection point meets the requirement or not, if so, enabling the ultra-high-order harmonic source to keep the operation parameters to continuously operate, and if not, returning to the step S103. According to the invention, compensation of specific-order ultra-high-order harmonics can be realized.

Description

technical field [0001] The invention relates to the technical field of electric power systems, in particular to a method for compensation and control of ultra-high harmonics. Background technique [0002] There are a large number of power electronic devices connected to the distribution network, which inject ultra-high harmonics into the power grid, which leads to a series of new problems in power quality. Ultra-high-order harmonics will cause some equipment to work abnormally, accelerate the heating of converters and other devices, and accelerate the loss and aging of components. In addition, ultra-high-order harmonics will affect communication equipment, resulting in abnormal operation of communication equipment. Active filtering is an effective means of eliminating harmonics. Its control method is to detect the voltage and current of the compensation object, and the compensation harmonic current calculated by command current calculation and the harmonic current in the loa...

AI Technical Summary

Problems solved by technology

However, for the ultra-high-order harmonics existing in the power grid, its order is on the same order of magnitude as the IGBT switching frequency, even higher than the IGBT switching frequency, and it is difficult to accurately measure the phase of a specific ultra-high-order harmonic in real time, so it is difficult to pass the traditional active filter The control algorithm filters out ultra-high harmonics

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