This study describes the derivation of an analytical model and simulation for the unified series-shunt compensator (USSC) for investigating power quality in power distribution system. The USSC simulation comprises of two 12-pulse inverters which were connected in series and in shunt with the system. A generalized sinusoidal pulse width modulation (SPWM) switching technique was developed in the proposed controller for fast control action of the USSC. Simulations were carried out using the PSCAD/EMTDC electromagnetic transient programs to examine the performance of the USSC model. Simulation results from the proposed model demonstrated the performance of the USSC and its effectiveness for voltage sag compensation, flicker reduction, voltage unbalance mitigation, power flow control and harmonics elimination.

Low frequency oscillation (LFO) is a serious threat to the interconnection of power system and its safe operation. In this paper, optimum damping performances over LFO is achieved by implementing Bijective Differential Search Algorithm (B-DSA) to large interconnected power system. Conventional two stages lead-lag compensator is optimized as the Power System Stabilizer (PSS) and Linear Time Invariant (LTI) State Space system models are used to conduct stability analysis of power system. The tuning problem of PSS in multimachine system was formulated as a multi-objectives function. The simulations are conducted in 5-AREA 16 Machine test power system for severe system fault in order to verify the robust design of damping controller. The obtained results are compared with standard DSA optimization technique. The findings show the improved damping achieved by B-DSA than DSA algorithm. The settling times achieved using B-DSA based designed PSSs are 3.74sec and 4.57sec for local mode and inter-area mode of oscillations respectively. The successful damping over oscillation modes of LFO justifies the proposed technique is efficient for the improvement of power system security in adverse condition.

Space vector pulse width modulation (SVPWM) technique is an advanced computation-intensive PWM method. It is the best among all PWM techniques for three-phase induction motor (TIM) drive applications because of its superior performance characteristics. In this paper, the use of artificial neural network (ANN) based SVPWM technique avoids the computational complex used in conventional SVM implementation. An ANN scheme structure is suggested to identify and approximate the conventional SVPWM for decrease the computational problem. Moreover, proportional-integral (PI) controller tuning is achieved using a particle swarm optimization (PSO) algorithm to improve the TIM speed controller’s response performance. By designing an appropriate PSO algorithm, kp and ki of the PI speed controller parameters are tuned for TIM to attain the best parameter values.