Power and energy systems 

About: Power and energy systems is an academic journal. The journal publishes majorly in the area(s): Electric power system & AC power. Over the lifetime, 542 publications have been published receiving 1534 citations.

Design of Fuzzy Logic based Maximum Power Point Tracking controller for solar array for cloudy weather conditions

Abstract: This paper proposes Maximum Power Point Tracking (MPPT) of a photovoltaic system under variable temperature and solar radiation conditions using Fuzzy Logic Algorithm. The cost of electricity from the PV array is more expensive than the electricity from the other non- renewable sources. So, it is necessary to operate the PV system at maximum efficiency by tracking its maximum power point at any weather conditions [1]. Boost converter increases output voltage of the solar panel and converter output voltage depends upon the duty cycle of the MOSFET present in the boost converter. The change in the duty cycle is done by Fuzzy logic controller by sensing the power output of the solar panel. The proposed controller is aimed at adjusting the duty cycle of the DC-DC converter switch to track the maximum power of a solar cell array. MATLAB/Simulink is used to develop and design the PV array system equipped with the proposed MPPT controller using fuzzy logic [2][3]. The results show that the proposed controller is able to track the MPP in a shorter time with less fluctuation. The complete hardware setup with fuzzy logic controller is implemented and the results are observed and compared with the system without MPPT (Fuzzy logic controller).

Fast fault detection for power distribution systems

Abstract: The main topic of this licentiate thesis is fast faultdetection. The thesis summaries the work performed in theproject“Fast fault detection for distributionsystems”.In the first chapters of the the ...

Feasibility Study of Hydrokinetic Power for Energy Access in Rural South Africa

Abstract: Renewable energy advocates, the South African Government and investors are more and more becoming aware of stream, river currents and their enormous associated energy potential. Since hydrokinetic power generation (HKP) relies basically on the extraction of energy from the natural velocity of free lowing water, this power system can be categorised as sources of flowing water with minimal civil infrastructure, environmental impacts and costs. This study investigates the possibility of using and developing hydrokinetic power to extend the reliable, affordable and sustainable electricity supplies for rural, remote and isolated loads in rural South Africa where reasonable water resource is available. Simulations are performed using the Hybrid Optimisation Model for Electric Renewable (HOMER) and the results are compared to those from other supply options such as standalone Photovoltaic system (PV), diesel generator (DG) and grid extension. Finally the paper points out some major challenges that are facing the development of this technology in South Africa.

Harmonic mitigation by SRF theory based active power filter using adaptive hysteresis control

Abstract: Power quality is an all-encompassing concept for a multitude of individual types of power system disturbances. The presence of harmonics in power supply network poses a severe power quality problem that results in greater power losses in the distribution system, interference problems in communication systems and, sometimes, in operation failures of electronic equipment. Shunt active power filters are employed to suppress the current harmonics and reduce the total harmonic distortion (THD). The voltage source inverter (VSI) is the core of an active power filter. The hysteresis current control is a method of controlling the VSI. Hysteresis control can be either of fixed band type or adaptive band type. In this paper, Synchronous Reference Frame (SRF) theory is implemented for the generation of reference current signals for the controller. This paper investigates the effectiveness of the proposed model in harmonics currents mitigation by simulating a model of a three-phase three-wire shunt active power filter based on adaptive hysteresis current control and SRF theory. Simulation results indicate that the proposed active power filter can restrain harmonics of electrical source current effectively.

Capacitors dispatch for quasi minimum energy loss in distribution systems using a loop-analysis based method

Abstract: The dispatch of capacitors in distribution systems for daily operation is investigated in this paper. The objective is to determine the next day operating schedule of the capacitors so as to minimize the total daily energy loss. A loop-analysis based analytic algorithm is developed in this paper to efficiently calculate the optimal settings of capacitor with time-varying load. Firstly, capacitors switching times are determined by a heuristic method. Then, the optimal settings of capacitors for all operating times are calculated by an iterative algorithm. Numerical simulations were done and the results show that the proposed algorithm has an approximately linear convergence and is efficient.