Study On DSTATCOM Application For Zhe-Gan Electrified Railway

With the non-linear power electronic devices were put into the electrical network increasingly, in the electrical network has produced a lot of harmonic and negative sequence component and reactive power. While the electric locomotive load for electric iron is a typical nonlinear harmonic source, the Zhejiang and Ganzhou electric railway line has brought certain influence for Jiangxi electrical network, And according to the superiority inhibition and compensation of harmonic and reactive power, improve power system stability for DSTATCOM, then choice DSTATCOM as the research object, to study the FACTS technology application in Jiangxi section for Zhe-Gan electrified railways. Full text including following several aspect contents:(1) Introduction the working principle for electrified railway power supply system, and analysis the Zhe-Gan traction power supply system, focuses on studying the structure and electrical principle for the electric railway harmonic source-electric locomotive, finally carries on the simulation analysis of the Shaoshan 4 modified electric locomotive in the Matlab simulation environment.(2) introduces the theory for dynamic reactive power compensation, DSTATCOM main circuit and basic working. principle for the voltage type bridge circuit, simultaneously, establishes DSTATCOM mathematical model that used the alignment quantity modeling for switch function method, analysis the relations between the inverter model and DSTATCOM model, finally discusses the DSTATCOM parameter selection, which lays an essential rationale for control system's design.(3) describes the detection and compensation for reactive power in several ways, carries on a simple analysis for current detection and compensation method that based on the instantaneous reactive power theory method, and analyzes the advantages and disadvantages for various detection methods, finally choices the improved supply voltage vector compensation current detection method which based on the synchronized coordinate method, the advantages for this method is can detect the reactive power, harmonics and negative sequence components for load current accurately that under unbalanced voltage grid, and can achieve comprehensive compensation for the load current power. Finally, takes simulation to various compensation methods.(4) Studies the current high-capacity main topology circuit and control method for DSTATCOM, in this paper several typical large-capacity main circuits for DSTATCOM have been studied, and inferences the output voltage expression for related electric circuits. To the four densities three level voltage invertor carry on simulation in single plane infinite large-scale system. And the Inverse system PI control and fuzzy adaptive control method results have been carried on comparison.(5) Realizes the TMS320LF2407 controller as control core for DSTATCOM, the hardware installment includes the control and protection circuit, the drive circuit, the power-on reset circuit, and the signal detection circuit, and establishes the corresponding software design flow chart.(6) Builds the simulation module for Shangrao traction substation, which harmonics and reactive was the most serious traction in Jiangxi Section of Zhe-Gan electrified railway, study installs the DSTATCOM device in this traction influence to improve the harmonics and reactive power. User Program Interface of Power System Application Package developed by EPRI of China is used to work out user program of DSTATCOM, and the user program is applied to Jiangxi electric power system to research the improving of DSTATCOM in voltage level and transient stability of it.