DSP-based Three-phase AC Power Quality Monitoring System

With the fast development of electric power system, power supply quality problem is attached more importance by relevant enterprises and the users. This problem relates the interests of power plants, power supply departments and power consumers. To realize high efficient, safe, economic operation of power system, it is very important to calculate and monitor three-phase ac electric parameter. It only has some routine measurement and protection circuit in usual electrical distributing box. So it is very valuable to design a three-phase power supply quality monitoring system include measure, display, communication and high efficient, low cost, high reliability which is used in power distribution room as monitoring device. According to the application requirements, the paper presents the design development of the three-phase ac based on DSP power quality monitoring systems, so as to realize the signals of the acquisition, electricity parameter calculation output and waveform display.The main works are as follows:i. This paper states the three-phase ac power quality monitoring system of application background, development purpose and meaning, etc. Based on the above analysis, this paper gives the design of the whole system solutions. In this paper the system makes full of DSP's high processing capability, and uses modular design to make the entire structure of the system simply.ii. This paper gives the hardware circuit design and hardware material. Among them, the three-phase voltage and current collection method is:the strong power convers into the weak electrical into ad7606 to ad sampling, then the sampled data delivered to DSP, sample chip applys 16bit ad7606 chip which support six-channel simultaneous translation. Then, DSP calculates the sampled data and analysis harmonics, the results displayed by lq043 at last. DSP applys ADI's BLACKFIN531-16 bit fixed-point chip, which can complete a multiplication and a addition within a instruction cycle.iii. This paper discusses the software design and program implementation. This system uses modularization and multi-thread model of producers/consumer mode to realize the design of software. All of which the calculation of electrical parameters is mainly used in multiplication and addition, the calculation of effective value used the root meam square(RMS), harmonic analysis used the fast Fourier transform (FFT), and done a simulation experiment of FFT.Through the hardware and software system integration commissioning, the system can real-time measure and display the RMS, power, harmonic, its measurement precision parameters such as can satisfy application requirements.