Study Of System Based On ARM In The Harmonics Investigations And Analysis Of Power System

With the development of national economy, power electronics equipments are large-scale used in all fields. They bring more and more harmonic pollution and endanger the safe operation of power equipment. The component of harmonic in the power network is very complicated. Therefore, harmonic detecting and analysis has become the premise for avoiding or reducing harmonic pollution.Through collecting lots of data and researching the relevant technology, this article analyzes the applying advantages of embedded system in the detecting and control of power system. According to LPC2214 processor with ARM7TDMI kernel as the core, it designs the detecting and analysis system for the harmonic in power network. This system mainly achieves the detecting and analysis for the harmonic of three-phase voltage and current. It includes data collection and harmonic analysis. In the part of hardware design, it details the working Principle of harmonic detecting and analysis and nails down the system function requirements. It designs every module for the system and inputs data of the power network to the system by Multi-channel synchronized gathering. It will complete operation processing work of inverted order processing and FFT by software. Then the content of various harmonics can be obtained.Through the Synchronizing circuit in this article, we can obtain the cycle of three-phase voltage and current in the power network, by Multi-channel synchronized gathering, to avoid or reduce the spectrum leakage and hurdle effect of FFT. Combined harmonic analysis requirements with characteristics of FFT, in order to reduce response time, increase computing speed, the actual sequence FFT to be chosen to integrate the date operation. That is, through a FFT computing to complete each phase voltage and current data from the time domain to the frequency conversion. It is obtained that the linear relationship between the frequency amplitude and time-domain amplitude. IFFT was avoided, so the computing speed has been further enhanced. Achieve the accurate detection of harmonic.Finally, through the test of sample machine, the harmonic detecting and analysis system which designed in this article can achieve harmonic content of the detection and analysis exactly and reliably.