Sensorless Feedforward Current Control of Dual-Active-Bridge DC/DC Converter for Micro-Grid Applications

摘要

In Dual-Active-Bridge converter control system, high frequency terminal current is usually measured then fed-back to the current mode controller. However, the measurement requires wide bandwidth sensors, fast and precise operational amplifier, and high sampling rate Analog to Digital conversion. This paper proposes a Proportional Integral Observer to estimate such the current to eliminate the need of current sensors. A combined feedforward-feedback control system is then developed to enhance the system dynamics and to regulate; the output voltage. The control system needs only the information of terminal voltages. Simulation and experiment results show that the observer performs fast and accurately with acceptable observation error; and the output voltage is well regulated regardless of load changes.