Research On Variable Frequency Driving And Control Of The Photovoltaic Pump System

After decades of development the photovoltaic pump (PV pump) system has become an important part of solar energy applications. Furthermore, with its tremendous social and economical advantages, the photovoltaic pump system has now been attached more and more importance. In this paper, the author develops two control systems of photovoltaic pump system driven by asynchronous motor, one is controlled by the special designed inverter, the other is controlled by the standard inverter .The main contents of this dissertation are as follow:1. Analyzing the form, configuration and traits of the PV pump system systematically.2. Some studies on the maximum power point tacking of the PV array, and the true maximum power point tracking (TMPPT) is realized by self-optimizing control.3. In order to improving the utilization of the DC voltage the control system optimizes the SPWM strategy by adopting the TRIPWM method and DC voltage compensation.4. Combined with the characteristics of the centrifugal pump, the control system optimizes the output V-f relation of the special designed inverter and provides its approximate realization.5. A special designed inverter is realized by adopting an advanced DSP (TMS320F2407A) as its control core, and the inverter has many protection measures such as water drained, low speed and over load protection.6. In order to improve the application of the photovoltaic pump system, the author designs a new control system of PV pump system using standard inverter. In this control system the MPPT controller is independent to realize the MPPT control of the PV array, and a standard inverter, instead of the special designed inverter, is used to control the pump load optimistically .