A les dual-mode fast power grid fundamental wave amplitude detection method and dual-mode detector

Abstract

The invention provides an LES dual-mode rapid power grid fundamental current amplitude detection method which comprises the following steps of S1, establishing an LES filter universal model; S2, by designing different actual sampling times N and sampling periods Ts, establishing a high-speed LES filter and a low-speed LES filter; S3, respectively feeding a certain phase of power grid voltage signal into the high-speed LES filter and the low-speed LES filter, and obtaining a high-speed LES detection value and a low-speed LES detection value; S4, obtaining an absolute value of a difference value of the high-speed and low-speed LES detection values; S5, feeding the absolute value into a hysteresis comparator, if the absolute value is greater than a hysteresis upper limit, using the high-speed LES detection value as a final value for output, and if the absolute value is smaller than a hysteresis lower limit, using the low-speed LES detection value as the final value for output. According to the dual-mode rapid power grid fundamental current amplitude detection method provided by the invention, power grid fundamental current amplitude detection time is shorter than a quarter of cycle wave, and meanwhile, effectively inhibits influence of low order harmonics on detection accuracy and promotes steady state detection accuracy.

Description

technical field [0001] The invention belongs to the technical field of electric network fundamental wave amplitude detection, and in particular relates to a method for detecting the fundamental wave amplitude of an LES dual-mode fast electric network and a dual-mode detector. Background technique [0002] Power electronic conversion equipment such as dynamic voltage restorers, photovoltaic inverters, wind power converters, and energy storage inverters need to detect the fundamental wave amplitude of the power grid in real time, so as to quickly adjust the control mode or control parameters, so as to maintain high-quality inverter products output performance. The existing traditional detection methods are slow, requiring at least half a grid cycle (10ms), which cannot meet the needs of high-performance converter control strategies. [0003] The LES filter (also known as the minimum variance filter) is a new fundamental wave amplitude detection method, which can complete the ...

AI Technical Summary

Problems solved by technology

Existing traditional detection methods are slow and require at least half a power grid cycle (10ms), which cannot meet the needs of high-performance converter control strategies

[0003] The LES filter (also known as the minimum variance filter) is a new fundamental wave amplitude detection method, which can complete the fundamental wave amplitude detection of the AC signal within two sampling periods in theory. Wave interference seriously affects the detection accuracy of LES

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