Z Source Inverter Performance Optimization Method And Application Research

Inverters are widely used in various industrial areas. Traditional inverter has two types: voltage source and current source. Due to its topological characteristics features. These types of the inverters in some occasions are applied by certain strict restriction, mainly embodied:step-down type or booster type converter. Both the main circuit of current transformers are not interchangeable which have poor universality. Electromagnetic is the interference of the pass-through phenomenon reduces reliability. Introducing Z source network solves the deficiencies of the traditional inverter effectively. The use of its unique impedance network with single stage step/down ability can satisfy the requirement of wide range input voltage changes.In order to contain the Z source converter of overall optimal or near optimal performance, The paper will improve Z source topology,parameter selection, modulation methods and application study. In order to reduce the number of devices, reduce stress and expand the purpose of boosting capacity. Booster mechanism based on traditional X type Z source circuit and through adjusting the traditional topology components,a kind of T type Z source topology is studied whose main performance indexes were compared.Secondly, Z small signal source network model was established based on the system under small disturbance linear model and by using the transfer function map the root locus, potter. Z source parameters such as capacitance, inductance, and direct duty ratio change system of zero and pole distribution of Z source was studied the influence of network parameters on the system dynamic performance. Based on SVPWM(Space Vector Pulse Width Modulation, SVPWM) zero vector optimization control strategy, the single zero vector SVPWM, alternation of zero vector SVPWM and optimal zero vector SVPWM modulation method were studied. Simulation verifies the zero vector optimization control strategy than traditional SVPWM modulation in lower device switching frequency, inverter output harmonic content, etc, have a bettereffect, making the Z source inverter optimal or near optimal overall system performance.Finally, Z source network control method is studied, using the capacitor voltage as indirect control the amount of feedback and making the Z source output voltage stability, which can adjust the voltage regulation as required. Z source inverter is studied in the application of PMSM(Permanent Magnet Synchronous Motor, PMSM) speed regulation, the application of based on the constant torque are analyzed with the combination of weak magnetic control Z source inverter speed control system. On condition that the input voltage may jump or drop, so it comes the simulation analysis about the load dumps or spurts situation.The experimental results showed that the Z source inverter can effectively cope with external disturbances, expand the inverter output voltage range, and have an advantage in terms of anti-jamming.