Research On Combined Control Of Active Power Filter And PV Generation

Nowadays the solar energy has become one of the most promising new energy thanks to its inexhaustible and environmental advantages. The photovoltaic technology has been deeply researched and popularized abroad and has entered the application stage in our country too. PV grid connected generation is one of the major development trends of photovoltaic generation. Meanwhile, with the development of the country's industrialization process, a large number of nonlinear loads have appeared. Harmonics and reactive current from nonlinear load induce that the power problem becomes more serious. However, passive filter can not meet power quality requirements. So Active Power Filter (APF) has become a hot topic at home and abroad.Although the APF and PV grid connected generation have the bright prospects, they still have shortages and face obstacles for development. For example, PV grid connected generation operates during the day and has to stop at night. This affects the stabilization of power system and the utilization ratio of equipment. Besides, they both have the shortages of high costs, low efficiency and support policy inadequacies and so on.For the shortages and obstacles above, this paper proposes combined control of APF and PV grid connected generation to promote the common development, and function of the combined system is further expanded making use of topology of APF and PV grid connected generation. Ultimately the control system of APF and PV generation is proposed completely, new system configuration and control strategy proposed not only can achieve functions of APF and PV grid connected generation at the same time, but also can compensate the voltage interruption to ensure uninterrupted work for load when the power interruption occurs.The combined control theory of APF and PV grid connected generation, evolution of the new system configuration, work principle and control strategy are researched in detail. This paper presents the specific technologies involved in the system proposed. The main contents are following: UPS and grid connected mode control and conversion technology, reactive and harmonic current detection technology, synthesis algorithm of harmonic current order and PV generation current order, the maximum power point tracking (MPPT) technology of PV array, power interruption detection technology, battery charge and discharge management and so on.Finally, the combined control system of APF and PV generation proposed is analyzed and verified by simulation with MATLAB/Simulink. A prototype based on TMS320LF2407DSP is designed and functions of combined system come true in prototype. The results of experiment and simulation prove the validity and feasibility of the system and control strategy above.