Design And Research Of High Voltage Frequency Control System In Modern Coal-fired Power Plant

As China's power grid expansion, the increase in total installed capacity of generating units, as well as the gap of peak-valley load, the load rate of generating units to reduce. 300MW-class generator should also take part in regulating the peak of load. The condition adjusting method of large-scale auxiliary for full capacity is no longer suited to peaking operation mode. Auxiliary asynchronous motor and its driver are working at low efficiency region, resulting in substantial energy waste. This paper can service 10 Units 300MW generating units of WanNeng company for the studying, research and analysis the the adjust way of throttle current widely used by power generation companies, pointing out that the great potential of saving energy and reducing consumption, proposed to carry out technological transformation the need. This paper research domestic frequency inverter technology, analyse technical characteristics of the three main implementation approach, including Y-A Transform, High-low-high Frequency Control System, and High-high Frequency Control System, full demonstration the feasibility of large capacity fans, pumps using high-volage direct VWF technology.This paper, condensate pumps and induced draft fan of the system 300MW units as an example, designed " One Drag Two ", "One Drag One" two different VVVF control system, and through the use of DCS distributed control system complete with auxiliary electrical interface design and control strategy, combined with the practical application of process electric heating body to increase, current instantaneous trip protection value is too large and so on, to carry out a deep theoretical analysis, an effective solution, successful solution to the practical application some of the problems to achieve system security, and stable operation of the request.From energy consumption data of the field debugging and performance analysis, the high voltage frequency control system can be used in high-voltage, high-power fans and pumps in power generation enterprises, not only has a good energy saving effect, and can achieve high-voltage motor soft-start, improve motor performance, significantly improve the regulation of quality generator sets, have good promotion significance in the important auxiliary in the same type of power industry.