An improved method for effecting feedback and open loop control for reactive power compensation and its application on induction generator

Abstract

Present power system scenario reveals that it has some limitations, leaving behind a scope of improvement in this area. Maintaining a stable, cost-effective and secure operation of power system is therefore a very important and challenging issue. Power can be utilized economically by minimizing its reactive component. At present thysistor-switched capacitors and thyristor-controlled reactors are used as 'active compensators'. Apart from cost considerations, these suffer from constructional limitations and are not suitable for large power handling. Moreover, the triggering circuits used for such capacitors and reactors are quite complicated. However the present work attempts to overcome the above drawbacks and provides an improved system for effecting feedback and open loop control for compensation in power system, which comprises of (i) step down transformer (T), (ii) bipolar junction transistor (BJT) or MOSFET, vacuum triode or any electronic amplifier (Q1), (iii) coupling capacitor (Ce) connected to transformer (T), (iv)power frequency choke (Le), (v) AC 'biasing inductor (Lc) AC biasing resistors (R1) and. (R3), (vi) blocking capacitor (Cb), (vii) DC emitter feedback resistor (R2), (viii) AC bypass capacitor (Cc), and AC biasing capacitor (Cz), (ix) DC biasing resistors (Rb1) and (Rb2) and (x) regulated DC supply voltage source (Vcc).