CAN based control of DC-DC converters in distributed generation units operating in master slave configuration

The introduction of a communication link improves the performance of a distributed generation (DG) system. At present, standard techniques based on RS485, Global Positioning System and Power Line Carrier Communication are used in DG systems for control and coordination. These techniques have many disadvantages related to their cost and the speed of data transfer. The issues associated with the establishment and requirements of a communication link between high-frequency power converters and the possible solutions are addressed in this paper, which proposes to use Controller Area Network (CAN) protocol for establishing the communication between the converters. CAN has the main advantage that it is capable of operating at speeds of up to 1 Mbit/s and can work faithfully under severe test conditions. The paper includes the design of the communication link which assists the control and coordination of the converters. Use of digital signal controllers enables acquisition of voltage and current parameters as well as data transmission to happen in real time. The communication link is designed using the eCAN module available in TMS320F28069 Piccolo series Digital Signal Controller (DSC) from Texas Instruments. The features of CAN protocol offer the advantage that the local slave DSCs can continue to communicate with each other even after the master controller fails. CAN also provides priority based access to the CAN bus and higher baud rates.