Analysis and Experimental Investigation of the Improved Distributed Electronic Load Controller

Stand-alone microhydro systems based on the self-exited induction generator (SEIG) are popular in developing countries. However, an electronic based controller is required to maintain the quality (voltage and frequency) of the generated power within an acceptable range. Conventionally, this controller is designed using a phase-controlled thyristor circuit (or more recently using a dc chopper circuit) and a fixed resistance dump load to receive the excess generated power. Generally, in small communities the total dissipated power in the dump load is greater than the consumed power by all the households. This problem of inefficient power usage can be solved by distributing the controller among households. The objective of this paper is to improve the distributed electronic load controller (DELC). As with the original DELC, the proposed improved DELC is used for two purposes: First, consuming the excess generated power individually by each household; and second, operating as a complementary device for voltage and frequency regulation of the SEIG. The detailed design and experimental verifications of the proposed improved DELC including the design of an appropriate input filter to minimize the network current distortion are presented here. Additionally, MATLAB simulations are used to study the interaction between the proposed improved DELC and the powerhouse controller (the ELC).