The Design And Control Of Converter For Pipeline Pressure Power Generator System

At present, natural gas mainly transports in high pressure pipeline.Natural gas in the pipeline needs to be highly pressured while transporting, which contains huge pressure energy.But the energy is lost after pressure regulating.In this thesis,the pressure driven power converter can make use of the lost energy efficiently by the pipeline pressure driven power generation technology.This thesis designed the overall structure of the power converter based on the power generator which is driven by the pipeline pressure.The converter contains rectifier module, battery storage unit, three-phase inverter module and energy balance resistant module. Made a detailed analysis on the working principle of each module of power converter and designed the circuit topology and specific parameters of the circuit of each module. Studied the working modes of the power converter and designed a control strategy of energy balance to keep the input and output power balanced. Main investigations of this thesis are as follows:(1) According to the demands of the power converter, this chapter designed the overall structure of the power converter. And took some circuit topologies of each module into comparison and chose the most suitable circuit topology. And designed the specific parameters of the circuit of rectifier module, battery storage unit and three-phase inverter module.(2) Investigated the startup process and working status of the power inverter, designed the work modes of the power converter according to state of charge of the battery. Studied the mathematical model of each module, found out the control object and objective of each module and designed the appropriate control strategy for each work mode.(3) In view of the generator outputs constant power while power converter is working in Mode III, this thesis designed a resistant control strategy for balancing input and output power. While the load of power converter changing, the strategy keeps input and output power balance and system work stable.(4) Set up a simulate model of power converter by using Matlab simulate software. Simulated each work mode of the power converter and verified the correctness of the circuit design and control algorithm for each module, proved the effectiveness of the step modulate strategy for balancing input and output power.