CAN based Control of DC-DC Converters in Distributed Generation Units Operating in Master Slave Configuration Sushil Thale,Vivek Agarwal, Senior Member IEEE Department of Electrical Engineering Indian Institute of Technology-Bombay, Mumbai, India ssthale@ee.iitb.ac.in, agarwal@ee.iitb.ac.in Keerthi Unni Department of Electrical Engineering Fr. C. Rodrigues Institute of Technology, Navi Mumbai, India unnikeerthy@gmail.com Abstract— 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. Keywords—distributed generation; micro sources; controller area network; baud rates; buck converter; PLCC I. INTRODUCTION The escalating demand for electric power has triggered the need for increased generation. Depletion of fossil fuels and increase in the CO 2 emissions emphasize the fact that renewable sources of energy must be utilized more extensively. Distributed generation (DG) is an approach that employs small-scale technologies to produce electricity close to the customer site. In contrast to the concept of centralized generation, DG systems employ numerous, but lower capacity plants and can provide power onsite with lesser dependence on the distribution and transmission grid [1]. DG also provides many potential benefits such as lower cost per unit, higher reliability and safety with smaller environmental impact as compared to the traditional power generators. DG technologies yield power in capacities that range from a fraction of a kiloWatt (kW) to about 100 MW. DG technologies include sources such as micro turbines, combustion gas turbines, fuel cells, solar PV, and wind turbines. The major technical issues with DGs are concerned with the protection aspects, control of power flow and load sharing as well as maintenance of power system stability in case of faults [1-4]. There are numerous methods used to control power electronic converters that operate on a DG system. The control methods that are not communication-based (such as droop based controllers) allow decentralized operation of the DG [5,6]. There is yet another classification of control methods in which some form of standard communication protocols such as PLCC, Ethernet [7] and GPS is involved [8]. The droop technique [9-17] has been widely used as a load-sharing scheme in conventional power systems with multiple generators. This load sharing technique is based on the power flow theory in an ac system which states that the active power flow is predominantly controlled by the power angle, while the reactive power is predominantly controlled by the voltage magnitude. Here, the system frequency is used as the control parameter in the generator control systems [11]. Similarly, a droop in the voltage amplitude with reactive power is used to ensure reactive power sharing. Yet another method known as the average power method is used in order to significantly reduce the sensitivity to voltage and current measurement error mismatches. This scheme guarantees good load-sharing of the fundamental components of the load currents [16]. CAN is a multi-master serial broadcast bus which eliminates the need for a master controller to be present to initiate 2012 IEEE International Conference on Power Electronics, Drives and Energy Systems December16-19, 2012, Bengaluru, India 978-1-4673-4508-8/12/$31.00 ©2012 IEEE