Research Of Pulse Generator In Cascade Multilevel Converter Based STATCOM

With the development of industry, customers become stricter with the power quality. The reactive load, especially the impulsive reactive load has very serious impact with the power quality .Var compensation is one of dominating methods for keeping power system in condition of favorable running. Now, var compensation devices in wide use are synchronous var compensation equipments combining with power electronic technique. Due to its advantages, STATCOM has been the main direction of developing synchronous var compensation technique. This paper has the detailed introduction, the theory of the cascade multilevel STATCOM. Designed a seven level OPWM pulse generator and a signal phase main frame of STATCOM.This paper presents a new optimized harmonic technique, which be used in designing the pulse generator for STATCOM employing cascaded inverters. Ordinary differential equations approach is used to calculate initial values of these equations, Newton-Raphson algorithm can be used to find the accurate solutions for training the ANN (Artificial Neural Networks).The paper also presents a method of designing seven levels pulse generator ,the simulation and experiment result show that this design provided good performance.The logic of seven levels OPWM pulse generator was designed with VHDL language in ispLever software platform. Through searching the index of modulation M and the switching angels stored in the memory of EMU, CPLD controller can save a lot of Logic units and generate accurate pulse .The simulation and experiment validated the accuracy of the generator.The logic of pulse generator was realized in CPLD LC4128V and The modulation index M was delivered by AT89C2051 between PC and CPLD through serial ports. The simulation and experiment validated good performance of the logic pulse generator and it can fully meet the requirements in STATCOM.