Research On New Technology Of Electrical Energy-saving In Enterprise High-low Voltage Distribution Grid

The wide use of inductive and nonlinear type load in industrial production makes lack of reactive power compensation and harmonic pollution of the enterprise distribution grid become more and more serious, which not only causes large power loss, but also lowers the power quality. At present, the compensation equipments applied in the enterprise distribution grid can reduce some power loss, but the disadvantages including single compensation means or high cost make them can't realize a satisfied electrical energy-saving effect. Beginning at reactive power compensation and harmonic elimination, this paper has done some research on high quality electrical energy-saving technology for high voltage distribution grid, low cost electrical energy-saving technology for low voltage distribution grid as well as electrical energy-saving system design.At the high voltage side of the enterprise distribution gird, based on the analysis of the necessity for high voltage high quality electrical energy-saving system, this paper proposes a high voltage high quality compensator (HVHQC) which is composed of injection type hybrid active power filter (IHAPF) and TCR, it can realize the comprehensive control for reactive power and harmonic so as to realize high voltage high quality electrical energy-saving. Based on its working principle, the control method of HVHQC is primarily studied, and it proposes voltage close-loop control to realize the dynamic regulation of reactive power and current close-loop control to eliminate the harmonic of the grid. This paper also improves the conventional control method to obtain a better dynamic performance.At the low voltage side of the enterprise distribution grid, based on the analysis of two types reactive power compensation devices namely TSC and DSTATCOM, combining the characteristics of them,this paper proposes a hybrid var compensator (HVC), which has advantages of low cost,large capacity and reactive power continuous regulation, so it can satisfy the requirement of enterprise for reactive power compensation.Based on its working characteristics,this paper proposes a control strategy based on expert decision,it uses the judgment rules to provide control signal for its discrete domain and continuous domain according to the reactive information acquired from the grid so as to coordinate its discrete domain and continuous domain and that can ensure its performance, the switching time control of thyristor and fuzzy PI control of DSTATCOM are analyzed.Based on the analysis of the above, this paper designs the whole scheme for electrical energy-saving system according to the actual situation of the enterprise distribution grid.The scheme uses the characteristics of the proposed equipments and distributes them at different side of enterprise distribution grid so as to realize electrical energy-saving. In the end, this paper gives the primary study for some parts design of the electrical energy-saving system such as the detection and control subsystem and the monitoring subsystem,they play a very important role in ensuring the performance of the electrical energy-saving system.