Research On 1.5kW PV AC Pump System

The photovoltaic(PV) pumping system has been widely used for its merits such as energy-conservation, environmental-friendliness and full-automation, by which not only the water supply for local residents can be satisfied, their economic efficiency can also be increased. Thus, researches to improve its performances are necessary to be made, so as to broaden its range of application.In this paper, a PV pumping controller is designed based on the development and application of PV pumping technology, and the research results are presented as follows.1. Models for each module of the PV pumping system are built, based on which the detailed analysis is carried out. The characteristics of the asynchronous motor and the pump are summarized, as well as the key to combining both technologies.2. A set of control strategy for PV pumping is designed, in which the SVPWM method based on DDS techniques is adopted and an optimization method of motor speed regulation is presented.3. Based on fuzzy PI control, a voltage and speed controller for the motor is designed to realize the direct drive of PV pumping generation, which can also regulate the water output in accordance with the power output of the PV array.4. The delay control strategy is added to the control system to prevent the motor from the damage caused by frequent start and stop in weak light.5. A set of PV pumping controller is designed based on a 16-bit MCU by Sunplus(SPMC752413A), and its feasibility has been verified by both simulation and experimental results.