Control of bidirectional DC-DC converter for battery operation
Date of Issue2017-08-30
School of Electrical and Electronic Engineering
Renewable energy sources usually have an unstable output. To utilize renewable energy source, an energy storage system is usually applied to supply or absorb the power difference between load demand and RES output. PV module and Lead acid battery are selected in the dissertation project. Since the voltage levels of PV output, battery and loads are not necessary identical, a DC-DC converter is designed to maintain a suitable voltage level to each module. When the converter is operating, regardless of the varying input power from the PV module, the output voltage to the load should be maintained stable by controlling the battery output. Also, the PV module should be controlled to operate at maximum output power if possible. A control program for battery is designed in the dissertation project. The DSP tms28335 is used as the main control unit. Double loop control is applied to the power converter and multiple sets of PID parameters are designed for various input conditions. Protection is included to the control program such as over voltage/current detections and soft starting. A two stage charging algorithm is adopted for the battery charging process.
DRNTU::Engineering::Electrical and electronic engineering