A Power Control Method For PV-Wind-Energy Storage Systems With Voltage Support Capability Using MATLAB

The paper presents a new Model Predictive Power and Voltage Control (MPPVC) scheme to control and coordinate the dc-dc converter, inverter and rectifier for grid connected PV-Wind-Energy Storage Systems. The cascaded control method with multiple feedback loops has been traditionally employed for voltage and power control of PV inverters. But this method has very limited power regulation capability. As the fast increasing penetration of PV and Wind power generation systems in the distribution network, the voltage rise/drop has become a serious problem impacting negatively on the power quality and grid stability. As we are using renewable energy sources, fluctuating outputs from energy sources and variable power demand may deteriorate the voltage quality. To overcome these problems a MPPVC is proposed without using any PID regulators. By regulating the dc-bus voltage and controlling the active and reactive power flows, this method can support the power grid to maintain stable voltage, frequency and improve power factor. By controlling the bidirectional dc-dc converter of the battery energy storage system, the fluctuating output from the renewable energy sources can be smoothed, while stable dc-bus voltage can be maintained. Compared with the traditional cascade control, the proposed method is simpler and shows better performance. Numerical simulation have been conducted on a PV-Wind-Energy Storage Systems to verify capability and effectiveness of the proposed control strategy.