Study Of The Nonlinear Load Measurement Issues

With the development of technology, the number of new electrical device is increasing. On the one hand, a lot of nonlinear load has been connected to the power system, such as arc furnace and electrified railway. This has polluted the power system more and more seriously, and the power quality has been decreased. In addition, the harmonics of the load affects the other electrical device in power system. On the other hand, some industries such as integrated circuit need higher quality power, so this brings more rigorous requirements for power quality. Therefore, the research of this paper has important significance.The structure and measure method of the current measurement equipments make that there are errors when they are used in power systems which contain harmonics. Therefore, there must be a reasonable method to separate the harmonic source at the point of common coupling and measure the harmonic power independently. In this way, we can accurately measure the power which is produced by basic wave and different harmonic source. This provides the foundation for solving the harmonic problem and punishing the harmonic source which has violated the standard.Based on analyzing the influence of harmonic to the measurement of power energy and the necessity of measuring the harmonic, this paper presents a metering harmonic energy method according to the harmonic detecting method, the harmonic power calculation method and the harmonic source separation method. This method can be used in measuring the harmonic power which is made by power system and customers at the point of common coupling.It has been proved by simulation experiment that the metering harmonic energy method is feasible. The scheme of the whole equipment is designed. It's divided into two modules. One is data collection module and the other is data process module. The hardware and software are implemented and debugged successfully. The core chip of data collection circuit is TMS320F2812 and the hardware and software are framed primal. Through the further work, the harmonic energy method and equipment can be applied in power system.