Nonlinear Instantaneous Reactive Power Quick Detection Technology And Digital Realization

In recent years, based on computer technology and power semiconductor manufacturing technology, the handling capability and switching speed of the switch power devices have been significantly improved. A variety of converters, frequency control devices, electronic ballasts and other electrical equipment in distribution network are increasing constantly. The applications and industrial market of power electronic devices continue to expand, which plays a big role in promoting the development of the national economy. However, because the power electronic device is a nonlinear time-varying topology load, now it has become the most important harmonic source in a power system, more than transformers, generators, EAF and other traditional harmonic source. In addition, power electronic devices produce a large number of harmonics, which also consumes reactive power and is an additional burden to the grid. Therefore, how to monitor the power parameters accurately in the complex non-linear environment and compensate reactive power quickly, which becomes a major issue faced by the power electronics, electric power system automation technology .In order to increase the accuracy and real time of the algorithm for existing dynamic reactive power compensation devices, improve equipment reliability and availability, the author develop a electromagnetic coupled 10kV dynamic reactive power compensation device, including capacitors, solid state relays , electromagnetic coupling system, protection circuit, radiator, high pressure transformer, switching power supply, controller and other hardware and software technology.In this paper, the following main technical achievements are made:(1) Select the instantaneous reactive power algorithm, combined with programming experience, reduce the sampling time, the operation and improve processing accuracy, the algorithm can meet within a frequency parameter calculation requirements.(2) analyse the principle of TSC devices, especially 10kV thyristor switched capacitor network access methods, use electromagnetic coupling system to avoid thyristors pressure problems.From an economic, reliability, this article has finally adopted the TSC compensation from a low-pressure side by electromagnetic coupling, switch all capacitors the dynamicly, which can solve high voltage SVC protection issues, including complex, high failure rate and slow response time, boost transformers do not need maintenance, and thyristor as a switch, rather than phase control role from the TCR, so it does not produce harmonics. It is a very economical, safe, reliable and effective solution that meets the needs of dynamic reactive power in industrial enterprises and substation. Develop successfully a dynamic reactive power compensation system, which already uses in Heshan Yayao 110kV substation of Guangdong Province, on-site operation results show that the system is running well and achieves the practical requirements.