Cogeneration in distribution system : planning, operation, transients

TLDR: In this article, abnormal conditions on a three-phase distribution feeder of industry like State Electricity Commission of Victoria (SECV) with several loads and a capacitor are investigated and interesting conclusions of practical importance are derived.

Abstract: This thesis relates to a study of abnormal conditions on a threephase distribution feeder of industry like State Electricity Commission of Victoria (SECV) with several loads and a capacitor bank. An induction generator, which plays the role of a dispersed storage and generation unit, driven by a hydraulic turbine, which is a common form of renewable energy scheme, is connected to the distribution feeder through a Δ/Y transformer. Transients caused switching of the induction generator, by single line-to-ground fault, double line-to-ground fault through contact resistances, broken conductor touching the ground through a small resistance, isolating the induction generator to form its own supply domain (islanding) etc are investigated and interesting conclusions of practical importance are derived. The IBM PC version 4 of the Electro-Magnetic-Transient Program - Alternative Transient Program (ATP), was used to solve this problem. The program also gives output results for automatic plotting in time domain. Accordingly, transient voltages at several nodes and transient currents at interesting points were plotted from the output results. Planning and operational aspects like voltage control, reliability, harmonics, earthing, and contractual matters between the private generator and the utility are also considered. Technical aspects interconnections between the private generation and the utility has been considered. Interesting conclusions, valuable for insulation co-ordination, interrupting duty on circuit breakers, effect on response of protective relays and automatic control systems are pointed out. It also considers security to personnel and protection of metering equipment. The thesis also offers guide for contractual matters between the utility and the private generation.