Multi-source Interconnected Power System Research Articles

Performance comparison of TCSC with TCPS and SSSC controllers in AGC of realistic interconnected multi-source power system

Abstract The primary goals of employing series flexible ac transmission system (FACTS) in automatic generation control (AGC) studies of interconnected power systems are mitigating area frequency and tie-line power oscillations. This paper compares dynamic performance of thyristor controlled series capacitor (TCSC) as damping controller with thyristor controlled phase shifter (TCPS) and static synchronous series compensator (SSSC) which are series FACTS damping controllers. Commonly used lead-lag controllers are used in structure of damping controllers. The effect of TCSC in tie-line power exchange is modeled mathematically based on the Taylor series expansion for small-signal load disturbance. The performance of the proposed TCSC controller in coordination with integral AGC is compared with cases of TCPS–AGC and SSSC–AGC. An improved particle swarm optimization (IPSO) algorithm and integral of time multiplied squared error (ITSE) performance index are used to design the damping controllers. A two-area power system having generations from reheat thermal, hydro, and gas units in each area is evaluated regarding nonlinearity effects of generation rate constraint (GRC) and governor dead band (GDB). The simulations results in MATLAB/SIMULINK environment show that the proposed TCSC–AGC yields superior performance than others in damping of area frequencies and tie-line oscillations. Furthermore, sensitivity analyses are performed to show greater robustness of TCSC–AGC.

Comparative performance analysis of fruit fly optimisation algorithm for multi‐area multi‐source automatic generation control under deregulated environment

A new swarm optimisation algorithm, that is, fruit fly optimisation algorithm is proposed to tuned several classical controllers for multi-area multi-source interconnected power system under deregulated environment. In deregulated environment, for multi-source combination of reheat thermal, hydro and nuclear generating units in each control area with appropriate generation rate constraint and AC/DC link. The performance of several controller such as integral (I), proportional-integral, proportional-integral-derivative, integral-double derivative (IDD) and proportional-integral-double derivative (PIDD) are compared under different power system scenario and it is found that PIDD controller performs better than other controllers. Then sensitivity analysis is performed with system parameter variation from their nominal values. Sensitivity analysis reveals that optimum gains of PIDD controller need not be reset for wide variation in system parameters.

A novel hybrid LUS–TLBO optimized fuzzy-PID controller for load frequency control of multi-source power system

Abstract In this paper, a novel hybrid Local Unimodal Sampling (LUS) and Teaching Learning Based Optimization (TLBO) based fuzzy-PID controller is proposed for load frequency control (LFC) of a two-area interconnected multi-source power system with and without HVDC link. Each area of the multi-source power system consists of a reheat thermal, a hydro and a gas unit. Fuzzy-PID and conventional PID controllers are used to study the dynamic performance of the power system by applying a step load change of 0.01 pu in area1. The scaling factors of the fuzzy-PID controllers and the conventional PID controllers’ gains are optimized using the proposed hybrid LUS and TLBO (LUS–TLBO) algorithm. The supremacy of the proposed LUS–TLBO algorithm optimized fuzzy-PID controller is proved for both the power systems (with and without HVDC link) by comparing the results with that of recently published article based on Differential Evolution (DE) algorithm optimized conventional PID controller for the same power systems. Again the robustness of the proposed controller for power system with AC tie-line only is studied under parametric variation conditions by varying all the parameters from −50% to 50% of their nominal values in steps of 25%. Finally it is seen that LUS–TLBO optimized fuzzy-PID controller exhibit superior performance as compared to DE optimized fuzzy-PID controller and hybrid LUS–TLBO, TLBO, LUS & DE optimized conventional PID controller.

TLBO optimized sliding mode controller for multi-area multi-source nonlinear interconnected AGC system

Abstract This paper represents design of output feedback sliding mode controller (SMC) for multi area multi-source interconnected power system. After designing output feedback SMC, teaching and learning based optimization (TLBO) technique is utilized to optimize feedback gain and switching vector of the controller. The superiority of the proposed approach is shown by comparing the result with output feedback tuned SMC with differential evolution and particle swarm optimization and state feedback SMC tuned with genetic algorithm for a two area thermal interconnected power system. Further, the proposed approach is extended to multi-area multi-source non linear automatic generation control (AGC) system with/without HVDC link. First area consists up thermal, hydro and gas; second area consists up thermal, hydro and nuclear as generating unit. Additionally, the superiority of proposed approach is shown by sensitivity analysis, which is carried out with wide changes in system parameters.

Effective oscillation damping of an interconnected multi-source power system with automatic generation control and TCSC

Abstract Stabilizing area frequency and tie-line power oscillations in interconnected power systems are main concerns that have received significant attention in automatic generation control (AGC) studies. This paper deals with modeling and simulation of thyristor controlled series capacitor (TCSC) based damping controller in coordination with AGC to damp the oscillations and thereby, improve the dynamic stability. The contribution of TCSC in tie-line power exchange is formulated analytically for small perturbation and a systematic method based on the Taylor series expansion is proposed for modeling of TCSC based damping controller. The integral gains of AGC and TCSC parameters are optimized simultaneously using an improved particle swarm optimization (IPSO) algorithm through minimizing integral of time multiplied squared error (ITSE) performance index. The performance of the proposed TCSC–AGC coordinated controller is compared with case of AGC alone. A two-area interconnected multi-source power system, including TCSC located in series with the tie-line, is studied considering nonlinearity effects of generation rate constraint (GRC) and governor dead band (GDB). Simulation results show that proposed controller shows greater performance in damping of the oscillations and enhancing the frequency stability. Furthermore, sensitivity analyses are carried out against system loading condition, parametric uncertainties, and different perturbation patterns to show the robustness of TCSC–AGC.