A New Formulation for Coordination of Directional Overcurrent Relays in Interconnected Networks for Better Miscoordination Suppression

Yazdaninejadi, Amin,Jannati, Jamil,Farsadi, Murtaza The Korean Institute of Electrical and Electronic 2017 Transactions on Electrical and Electronic Material Vol.18 No.3

A safe and reliable protection system in distribution networks, specifically, those hosting distribution generation units, needs a robust over-current protection scheme. To avoid unintentional DG disconnection during fault conditions, a protection system should operate quickly and selectively. Therefore, to achieve this aim, satisfying coordination constraints are important for any protection scheme in distribution networks; these pose a challenging task in interconnected and large-scale networks. In this paper, a new coordination strategy, based on the same non-standard time-current curve for all relays, in order to find optimal coordination of directional over-current relays, is proposed. The main aim is to reduce violations, especially miscoordination between pair relays. Besides this, the overall time of operation of relays during primary and backup operations should be minimized concurrently. This work is being tackled based on genetic algorithms and motivated by the heuristic algorithm. For the numerical analysis, to show the superiority of this coordination strategy, the IEEE 30-bus test system, with a mesh structure and supplemented with distributed generation, is put under extensive simulations, and the obtained results are discussed in depth.

A New Formulation for Coordination of Directional Overcurrent Relays in Interconnected Networks for Better Miscoordination Suppression

Amin Yazdaninejadi,Jamil Jannati,Murtaza Farsadi 한국전기전자재료학회 2017 Transactions on Electrical and Electronic Material Vol.18 No.3

A safe and reliable protection system in distribution networks, specifically, those hosting distribution generation units,needs a robust over-current protection scheme. To avoid unintentional DG disconnection during fault conditions,a protection system should operate quickly and selectively. Therefore, to achieve this aim, satisfying coordinationconstraints are important for any protection scheme in distribution networks; these pose a challenging task ininterconnected and large-scale networks. In this paper, a new coordination strategy, based on the same non-standardtime-current curve for all relays, in order to find optimal coordination of directional over-current relays, is proposed. The main aim is to reduce violations, especially miscoordination between pair relays. Besides this, the overall timeof operation of relays during primary and backup operations should be minimized concurrently. This work is beingtackled based on genetic algorithms and motivated by the heuristic algorithm. For the numerical analysis, to show thesuperiority of this coordination strategy, the IEEE 30-bus test system, with a mesh structure and supplemented withdistributed generation, is put under extensive simulations, and the obtained results are discussed in depth.

Power System Rotor Angle Stability Improvement via Coordinated Design of AVR, PSS2B, and TCSC-Based Damping Controller

Jannati, Jamil,Yazdaninejadi, Amin,Nazarpour, Daryush The Korean Institute of Electrical and Electronic 2016 Transactions on Electrical and Electronic Material Vol.17 No.6

The current study is dedicated to design a novel coordinated controller to effectively increase power system rotor angle stability. In doing so, the coordinated design of an AVR (automatic voltage regulator), PSS2B, and TCSC (thyristor controlled series capacitor)-based POD (power oscillation damping) controller is proposed. Although the recently employed coordination between a CPSS (conventional power system stabilizer) and a TCSC-based POD controller has been shown to improve power system damping characteristics, neglecting the negative impact of existing high-gain AVR on the damping torque by considering its parameters as given values, may reduce the effectiveness of a CPSS-POD controller. Thus, using a technologically viable stabilizer such as PSS2B rather than the CPSS in a coordinated scheme with an AVR and POD controller can constitute a well-established design with a structure that as a high potential to significantly improve the rotor angle stability. The design procedure is formulated as an optimization problem in which the ITSE (integral of time multiplied squared error) performance index as an objective function is minimized by employing an IPSO (improved particle swarm optimization) algorithm to tune adjustable parameters. The robustness of the coordinated designs is guaranteed by concurrently considering some operating conditions in the optimization process. To evaluate the performance of the proposed controllers, eigenvalue analysis and time domain simulations were performed for different operating points and perturbations simulated on 2A4M (two-area four-machine) power systems in MATLAB/Simulink. The results reveal that surpassing improvement in damping of oscillations is achieved in comparison with the CPSS-TCSC coordination.

Simultaneous Planning of Renewable/ Non-Renewable Distributed Generation Units and Energy Storage Systems in Distribution Networks

Jannati, Jamil,Yazdaninejadi, Amin,Talavat, Vahid The Korean Institute of Electrical and Electronic 2017 Transactions on Electrical and Electronic Material Vol.18 No.2

The increased diversity of different types of energy sources requires moving towards smart distribution networks. This paper proposes a probabilistic DG (distributed generation) units planning model to determine technology type, capacity and location of DG units while simultaneously allocating ESS (energy storage systems) based on pre-determined capacities. This problem is studied in a wind integrated power system considering loads, prices and wind power generation uncertainties. A suitable method for DG unit planning will reduce costs and improve reliability concerns. Objective function is a cost function that minimizes DG investment and operational cost, purchased energy costs from upstream networks, the defined cost to reliability index, energy losses and the investment and degradation costs of ESS. Electrical load is a time variable and the model simulates a typical radial network successfully. The proposed model was solved using the DICOPT solver under GAMS optimization software.

Power System Rotor Angle Stability Improvement via Coordinated Design of AVR, PSS2B, and TCSC-Based Damping Controller

Jamil Jannati,Amin Yazdaninejadi,Daryush Nazarpour 한국전기전자재료학회 2016 Transactions on Electrical and Electronic Material Vol.17 No.6

The current study is dedicated to design a novel coordinated controller to effectively increase power system rotorangle stability. In doing so, the coordinated design of an AVR (automatic voltage regulator), PSS2B, and TCSC (thyristorcontrolled series capacitor)-based POD (power oscillation damping) controller is proposed. Although the recentlyemployed coordination between a CPSS (conventional power system stabilizer) and a TCSC-based POD controller hasbeen shown to improve power system damping characteristics, neglecting the negative impact of existing high-gainAVR on the damping torque by considering its parameters as given values, may reduce the effectiveness of a CPSSPODcontroller. Thus, using a technologically viable stabilizer such as PSS2B rather than the CPSS in a coordinatedscheme with an AVR and POD controller can constitute a well-established design with a structure that as a highpotential to significantly improve the rotor angle stability. The design procedure is formulated as an optimizationproblem in which the ITSE (integral of time multiplied squared error) performance index as an objective function isminimized by employing an IPSO (improved particle swarm optimization) algorithm to tune adjustable parameters. The robustness of the coordinated designs is guaranteed by concurrently considering some operating conditionsin the optimization process. To evaluate the performance of the proposed controllers, eigenvalue analysis and timedomain simulations were performed for different operating points and perturbations simulated on 2A4M (two-areafour-machine) power systems in MATLAB/Simulink. The results reveal that surpassing improvement in damping ofoscillations is achieved in comparison with the CPSS-TCSC coordination.

Simultaneous Planning of Renewable/ Non-Renewable Distributed Generation Units and Energy Storage Systems in Distribution Networks

Jamil Jannati,Amin Yazdaninejadi,Vahid Talavat 한국전기전자재료학회 2017 Transactions on Electrical and Electronic Material Vol.18 No.2

The increased diversity of different types of energy sources requires moving towards smart distribution networks. This paper proposes a probabilistic DG (distributed generation) units planning model to determine technologytype, capacity and location of DG units while simultaneously allocating ESS (energy storage systems) based on predeterminedcapacities. This problem is studied in a wind integrated power system considering loads, prices and windpower generation uncertainties. A suitable method for DG unit planning will reduce costs and improve reliabilityconcerns. Objective function is a cost function that minimizes DG investment and operational cost, purchased energycosts from upstream networks, the defined cost to reliability index, energy losses and the investment and degradationcosts of ESS. Electrical load is a time variable and the model simulates a typical radial network successfully. Theproposed model was solved using the DICOPT solver under GAMS optimization software.