The Design And Implement Of Dynamic Power Quality Monitor

During the recent years, power quality problems have being attracted by most people. On one hand, the application of device of large power electronics and nonlinear equipments, which is the result of the curve of voltage and current has aberration in power system and even worsen the power quality. On the other hand, with the development of the level of industrial automation, the application of aptitude devices such as mini processor and PLD and so on is in industrial process control, which are impacted by the disturbance of power system, so it's has higher standard.In our country, the power market is gradually building and it's improved all the time, in this background, the power system not only need to satisfy the customers in amount, but also in quality.In this paper, according to the platform of hardware and software, it presents the multi-channel non-gapped sampling technique on line based on CPLD, DSP, FIFO as center, the configuration of hardware and software is described particularly. To theproblem of transient power quality in power quality management systems-theanalysis of disturbing signal of dynamic power quality, there are two methods: Average squaring root and the Method of distorting voltage. The former doesn't provide the time when then voltage depresses and possible phase varies, and the latter doesn't give the values of magnitude and phase, not for monitoring on line either. As is describes above, this paper gives the method, Instantaneous dqTransforming, it can calculate the virtual value of dynamic signals, and also, Instantaneous dq Transforming can measure the moment of dip happens, magnitude, phase. Additionally, in this paper, epenthesis values and numeral filter are utilized after using Instantaneous dq Transforming, in correction of waveforms of virtual values. And the program of this part is taken to implement on platform of VB6. According to the different requires of management department and customers in report of power quality, this paper presents the mode of dynamic combination report and takes it into practice.The idea and design has been taken into practice in the monitoring management system of power quality in Weigang Group, which is the critical customer of Neijiang power system. The monitor is used to monitor public interconnection points between the power system and the corporation, which is the large and critical customer. According to the practice, PQM (Power Quality Monitoring) not only can solve the problems of the accurate of measurement in stabile power system such as harmonic, instantaneous voltage fluctuation and so on, but also transient power issues such as voltage well, voltage sag and voltage interruption and so on. Additionally, PQM provides the flexible and various display and output. The idea and design of PQM gives not only the full, particular and on line information of power quality service, but also firming the foundation of power market for further development.