Fundamental wave and harmonic wave electric energy metering method

Abstract

The invention relates to a fundamental wave and harmonic wave electric energy metering method comprising the following steps that the voltage and current values of one cycle of a measured system are sampled, time domain resampling is performed through a first-order Newton interpolation formula and then FFT analysis is performed so that the component of each order of frequency domain is obtained: the voltage real component Ureh, the voltage imaginary component Uimh, the current real component Ireh and the current imaginary component Iimh; frequency domain amplitude compensation is performed on each component so that Ure'h, Uim'h, Ire'h and Iimh' are obtained; and finally fundamental wave and harmonic wave electric parameters are calculated. According to the method, only simple multiplication and addition operation requires to be performed without complex equation solving or division operation so that the operation burden is low, implementation is easy and convenient and fixed-point implementation is easy. According to the method, the MATLAB simulation experiment proves that the fundamental wave active and reactive power pulse error is within 0.02% and the harmonic voltage and current amplitude precision is maintained within + / -3%.

Description

technical field [0001] The invention belongs to the field of power system electric energy measurement, and in particular relates to a fundamental and harmonic electric energy measurement method. Background technique [0002] As we all know, the problem of harmonic pollution poses a certain threat to the safety, stability and economic operation of the power system; therefore, the accurate detection and measurement of fundamental and harmonic electrical parameters is an important technical indicator of power grid power metering. In recent years, the newly promulgated technical standards have also put forward higher requirements for this indicator. For example, GB / T17215.302-2013 has clear requirements for the measurement accuracy of active fundamental wave and harmonic energy, and IEC 62053-24:2014 has clear requirements It is proposed that fundamental wave reactive power will be used in reactive energy measurement in the future, and the accuracy must meet the requirements of ...

AI Technical Summary

Problems solved by technology

The disadvantage of the existing technology is that if it is necessary to obtain high-precision fundamental and harmonic electrical parameters, it is necessary to use window functions with relatively complex calculations, such as Blackman-Harris windows and Kaiser windows. Using the former requires solving unary quintic Equation or unary heptadic equation, and the latter needs to solve the transcendental equation. The solution of the root of the complex equation undoubtedly increases the difficulty of realization, and the accuracy of the root of the equation directly affects the accuracy of the fundamental wave and harmonic electrical parameters. It is even more difficult for a fixed-point processor; in addition to solving the equation, the windowed frequency domain interpolation method also needs to perform peak search and complex division operations. These operations are very computationally intensive. It will take up most of the processor resources, and the real-time performance will be greatly reduced

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