Research On Pmsm Drive Control System Based On VSR-VSI

Within the background of increasing demand for energy and environmental protection of modern society, it is very necessary and urgent to develop high efficiency motor drive control system. Voltage source rectifier (VSR) has constantly been focused recent years, for its advantages of sinusoidal input current, high power factor and bidirectional power flow. Howerver, it still has a long way to apply the voltage source rectifier to voltage source inverter (VSR-VSI) into AC motor drive and control system to attain the four-quadrant operation and energy regeneration. Therefore, the VSR-VSI based permanent magnet synchronous motor (PMSM) drive control system is selected in this dissertation to carrie out a deep research on control strategy of VSR active front end (AFE) and PMSM regeneration, integrated implementation method, coordinative control technology, focused on the new features of controllable DC-bus voltage and energy reversible flowing. It has both important theoretical significance and practical value.First, the mathematical model of VSR-VSI PMSM system is established in the dq coordinate, and the value range of the equivalent switching functions is derived. And then, the definition of reversible operation is given, which lends theoretical foundation for the ensuing research. After that, by analyzing the mutual constraints of DC bus voltage, grid voltage, input current and load current and the stability of current equilibrium point in the unity power factor operating mode, it is pointed out that the whole system has a character of bidirectional asymmetry operation, which supports improvement of the ensuing control strategy theoretically.In order to solve the traditional PI control method of VSR AFE used in motor drive failing to meet the bus voltage set point stabilization and disturbance restrain simultaneously, a novel I-PD voltage control strategy is proposed basing on the two degree of freedom (TDOF) control theory. The design method of controller parameters is discussed in details and system performance analysis is given.Simulation and experimental results show that this strategy can effectively depress the bus voltage overshoot as well as current surge, and reduce the system influences caused by load disturbance and grid voltage fluctuations. In order to speed up the dynamic response of the DC bus voltage under traditional cascade control structure, a new direct voltage control method is proposed, combining voltage error and current error to control input variables following the differential geometry linearization theory. This method can not only effectively simplify the control law expression, reduce calculated variables, but also guarantee the global stability of the entire system. By making use of voltage error equation, quantitative analysis of the steady and dynamic performance under different load disturbance is given, and the impact when the system parameter existing error is analyzed. Simulation and experimental results show that this method can increase the system dynamic response speed even under large load disturbance.To improve the control of regeneration energy of PMSM in the VSR-VSI drive, braking procedure of PMSM under flux-oriented-control is analyzed, and the regeneration model is established according to three typical loads of PMSM under constant braking torque mode. Further more, an optimal control strategy of energy regeneration is proposed with saturation current constrain by applied the instantaneous power theory. Simulation and experimental results show that the proposed strategy can effectively reduce regenerative braking power shock, and improve the efficiency of regenerative energy.Finally, to solve the problem of coordinate controlling of VSR and PMSM, an instantaneous power calculation based system integrated solution is proposed. And an integrated VSR-VSI PMSM drive control system is implemented basing upon control platform which comprises of single Tricore digital signal controller (DSC), and the integrated implementations of hardware and software are achieved. The experimental results demonstrate that the proposed energy optimization control strategy can achieve four-quadrant operation, energy bidirectional flow, smoothly steady state operation with high dynamic disturbance rejection performance, and can reduce the influence due to asymmetrical operation effectively.