DESIGN, TESTING AND SENSITIVITY ANALYSIS OF ELC

Abstract

This Dissertation presents design, testing and sensitivity analysis of an electronic load controller (ELC) for single-phase synchronous generators suitable for stand-alone micro-hydropower generation, with constant input power. The synchronous generator may be used to generate constant frequency if the electrical load is maintained constant at its terminals. A suitable control scheme has to be developed such that the load on the synchronous generator remains constant despite change in the consumer load. In such applications, water is freely available and, hence, a simple and cheap controller has to be developed, which, can operate almost unattended in remote and hilly regions. In this scheme, the principle of phase angle control of back to back thyristor is used. A thyristor is fired at a specific delay angle relative to the zero voltage crossing of the sine wave (symmetrical for both halves of the sine wave). The thyristor commutates at next zero crossing. Switching occurs a twice the frequency and generates total harmonic distortion (THD) as high as 35 - 40 % in current with added reactive power burden. This scheme can continuously vary the dump power over nearly the entire range from zero to full load as the delay angle varies from 180 degree to 0 degree.