Reactive power adaptive calculating method

Abstract

The invention belongs to the power grid electric energy metering technology field, particularly relates to a reactive power adaptive calculating method. The method comprises the steps of setting a sampling period as T, sampling a voltage signal and a current signal at a load end of a power grid synchronously and regularly to obtain voltage sampling data u(t) and current sampling data i(t) at the same time; then conducting condition coupling analysis to the voltage sampling data u(t) and the current sampling data i(t) to obtain an AC component number N; conducting Hilbert transformation to the voltage sampling data u(t); finally improving an expansion Prony method to fit AC voltages u1, u2,..., uN, voltage u'1, u'2,..., u'N after Hilbert transformation, AC i1, i2,..., iN, and frequency f1, f2,..., fN; and calculating reactive power Q1, Q2,..., QN of each AC component. According to the invention, under the condition that the system parameter changes randomly, the AC load power of an electric power system can be measured accurately; an effective control strategy for stable running of the electric power system is provided; the method can be realized easily and executed simply with high accuracy; and the method can be widely in power grid electric energy power metering.

Description

technical field [0001] The invention belongs to the technical field of grid electric energy metering, in particular to a reactive power self-adaptive calculation method. Background technique [0002] With the generation of various energy-saving appliances and pulsed electric energy loads like fast charging stations, the parameters of the power system are becoming more and more complex, which brings certain difficulties to the accurate measurement of electric energy. In terms of ensuring the stability of the power system, the control strategy can be realized by adjusting the active power and reactive power. Therefore, the study of the power measurement method under the condition of randomly adjustable system parameters has a guiding effect on the power supply reliability and economy of the power system. [0003] In the actual power system energy measurement, it is usually necessary to decompose the voltage signal or current signal into fundamental wave components and multiple...

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Problems solved by technology

[0004] Based on the analysis method of Fourier transform, the discrete Fourier transform can analyze non-integer harmonics, but due to the large amount of calculation, the hardware requirements are high, although the fast Fourier transform reduces the performance of the discrete Fourier transform. The amount of calculation, but due to the fence effect can not extract the interharmonic from the aliased spectrum; the analysis method based on wavelet transform, because the frequency division function of different wavelet filters and the difference in energy leakage are not clear, so it is necessary A scheme is proposed to accurately measure the AC load power of the power system under random changes in system parameters, and to provide an effective control strategy for the stable operation of the power system

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