Majid Nayeripour

Design of sliding mode controller for UPFC to improve power oscillation damping

In this paper, a new indirect method of sliding mode control (SMC) for series converter of unified power flow controller (UPFC) is proposed. In this method, the dynamic model of controller is obtained through special concepts of state variable transform, feedback linearization and differentially flat output. This new and simple control strategy has been developed base on the modified SMC principles which utilizes only the active and reactive output powers as the control inputs. Since these measurable control inputs are known as differentially flat outputs, they have a direct influence on the state variables of series converter to control them with the capability of power oscillation damping. The absence of discontinuous component input to UPFC controller avoids the chattering effect on state variables, especially on the dc capacitor voltage of inverters. For the validation of the proposed new controller, the obtained results were compared with results obtained from the PI controller.

Hybrid Fuzzy Adaptive Particle Swarm Optimization and Differential Evolution Algorithm for Distribution Feeder Reconfiguration

Abstract Network reconfiguration for loss reduction in a distribution system is a very important way to save the electrical energy. This article proposes a hybrid evolutionary algorithm to solve the distribution feeder reconfiguration problem. The algorithm combines a fuzzy adaptive particle swarm optimization with a differential evolution algorithm, called the fuzzy adaptive particle swarm optimization–differential evolution. The fuzzy adaptive particle swarm optimization includes two parts. The first part is fuzzy adaptive binary particle swarm optimization, which determines the status of tie switches (open or closed), and the second part is fuzzy adaptive discrete particle swarm optimization, which determines the sectionalizing switch number. In the proposed algorithm, due to the results of binary particle swarm optimization and discrete particle swarm optimization algorithms that highly depend on the values of their parameters (such as the inertia weight and learning factors), a fuzzy system is employed to adaptively adjust the parameters during the search process. The differential evolution algorithm is combined with the fuzzy adaptive particle swarm optimization algorithm to improve its performance. The proposed algorithm is tested on two distribution test feeders. The results of simulation show that the proposed method is very powerful and is guaranteed to obtain the global optimization.

Interactive fuzzy binary shuffled frog leaping algorithm for multi-objective reliable economic power distribution system expansion planning

A new method to solve non-linear mixed-integer constrained power distribution system expansion planning problems in presence of distributed generations (DGs) is investigated in this paper. The objective functions of this model are total energy not supplied (ENS) as reliability index, total expansion cost, and total voltage deviation. The final optimal solution proposes type, location and size of new equipment to meet the demand growth in the distribution system. An intelligent population based optimization algorithm called Binary Shuffled Frog Leaping Algorithm (BSFLA) is proposed to solve the problem. The interactive fuzzy method is used to solve the multi-objective optimization problem, so that conflicting objective functions can be easily consider together and achieve a set of non-dominated (Pareto-optimal) solutions. The model is applied on a standard IEEE distribution system to demonstrate the efficiency and feasibility of proposed method.

Application of Modified Shuffled Frog Leaping Algorithm on Optimal Power Flow Incorporating Unified Power Flow Controller

(UPFC). In a power system, installing the UPFC can improve power transfer capability, transient stability, and system reliability, reduce loss in the transmission network and the fuel cost of generators. In order to apply UPFC in OPF problem, a mathematical model needs to be set for it. In this paper a new model based on the Injection Power Model (IPM) is presented. Due to the nonlinearity of OPF problem, it is essential to use an exact and strong method to solve it. In recent years, evolutionary and heuristic advantages of algorithms in terms of the modeling capability and search power lead to their higher application in the complicate problem like OPF. This paper presents a modified shuffle frog-leaping algorithm (MSLFA) to solve the OPF problem. The MSFLA has a flexible and well balanced mechanism in order to enhance and adapt to global and local exploration abilities. Simulation results on the modified IEEE 30-bus and 5-bus test systems indicate that the proposed MSLFA algorithm approach can obtain better solutions than other optimization algorithms.

Design and analysis of fuzzy power system stabilizer

This paper introduces a fuzzy controller as a power system stabilizer (PSS). The fuzzy controller has been designed to provide a supplementary signal to the excitation system of the synchronous generator. Three proposed types of fuzzy control algorithms are inspected and tested in the case of single machine that connected to the network, for various types of disturbance. To show the effectiveness of the proposed controller in damping oscillations a three-phase short circuit condition under various loading conditions is presented to illustrate the application of the developed methodology. The obtained results show that the proposed controller for stabilizing power system can provide very good damping characteristic, comparison with the conventional PSS, through wide range of operating condition for power system and improves dynamic operating of the system substantially.

A new distribution power system planning approach for distributed generations with respect to reliability assessment

Conventional methods for solving distribution systems planning (DSP) problem are related to the expansion of distribution systems such as substation reinforcement and feeder replacement. Nowadays, distributed generations (DGs) in various types are a new option for DSP. This paper presents a new approach to solve the DSP problem including DGs with respect to the reliability of the system. The impact of different types of DGs in order to improve the system reliability are modeled and studied by the adequacy transition rate using the Markov model. The objective functions of this optimization problem are power losses, DGs installation and operation cost, reliability indices such as energy not supplied, average interruption frequency, and average interruption duration. Since this optimization problem has a nonlinear complex nature, classical mathematical methods cannot guarantee to achieve the global optimum solution. To solve this problem, a fuzzy interactive multi-objective particle swarm optimization is dev...

Maximum constant boost control for QZSI in a fuel cell system

Fuel cell systems are a type of DG systems and can offer the prospect of supplying the world with safe, clean, efficient, sustainable electrical energy. In order to control of fuel cell systems, in this paper proposed QZSI and maximum constant boost control. The quasi-Z-source inverter (QZSI) is similar to the ZSI. The QZSI has been developed which feature several improvements and no disadvantages when compared to the ZSI. Simulation results will be presented to demonstrate the new features.

Model predictive control of distributed generation micro-grids in island and grid connected operation under balanced and unbalanced conditions

Model Predictive Control (MPC) uses the model of system at current time to predict the system behavior at the future sampling interval in the prediction horizon and sets a number of variables to their references due to their controllability from input variables. This paper concentrates on the design and analysis of a controller for Distributed Generation (DG) microgrids in islanding and grid connected operation modes using a Receding Horizon MPC scheme. In this contribution, active and reactive powers are used in a cost function as an inner control loop to produce switching states. Two outer voltage and frequency droop loops share active and reactive powers between DGs in the microgrid. The design concept of the proposed control system is evaluated through simulation studies and experiment under different test scenarios. The impact of the simulation and the experimental results shows that the operations of the DG units within the microgrid can be coordinated effectively under the proposed control system t...

Protection scheme for full wave controlled three phase rectifier base on multi fault detection algorithms

Different techniques of converter faults detection is studied. Between them zero components, min-max-average and slop of space vector methods are chosen because they need little computation time and complexity. A new fault detection method is proposed base on negative component for the first time in this paper. Then this method plus the three selected algorithms are used to developing a protection scheme that detects converter switches faults as increasing ON resistance, decreasing OFF resistance, short circuit and open circuit faults. As protection scheme must have correct operation in different situations, three transient detector units are used for diagnosing transients like phase broken, input voltage harmonics, low current and input ac transient units that detect out of protection zone conditions. Test results of the proposed protection scheme in different situations discover the efficiency of the proposed protection scheme in faults diagnostics and protection operation.

Fuzzy Controller Design of TCSC with ANFIS to Improve the Dynamic Stability of Power System

In this paper, a new variable fuzzy control algorithm is proposed for thyristor-controlled series capacitor (TCSC) to improve power system dynamic performance. Rules of adaptive neuron fuzzy inference system (ANFIS) devise this fuzzy controller for TCSC in power system. ANFIS uses a hybrid learning algorithm to identify the membership function parameters of Sugeno-type fuzzy inference system. Consequences of this control trend are compared with PI controller and it is shown by using fuzzy controller the system has more stable power flow and less power oscillations. Simulation results signify power stability improvement of two-area power system by using fuzzy controller in TCSC than traditional PI controller.