This paper deals with a integrated Electronic Load Controller (IELC) for an isolated asynchronous generator (IAG), used in constant power pico hydro power generation for feeding three-phase four-wire loads. The proposed IELC is used to control the voltage and frequency of IAG in the integrated manner. This IELC is realised using a T-connected transformer and three-leg insulated gate bipolar tra...

The problem of controlling three-phase, four-leg shunt active power filters (SAPF) is addressed in presence of nonlinear and/or unbalanced loads. A new control model for four-leg SAPF, taking into account for the electrical grid line impedance, is developed. The control objective is threefold: (i) compensating for the current harmonics and the reactive power absorbed by the nonlinear load; (ii)...

Power properties of unbalanced linear time-invariant (LTI) loads in three-phase three-wire circuits at asymmetrical and nonsinusoidal supply voltages are investigated in this paper. It is demonstrated that the supply current of such loads can be decomposed into Currents’ Physical Components (CPC), associated with distinctive physical phenomena in the load. The power equation is developed and it...

Uncertainty analysis of future system operation is the key feature of current study. This paper shows that how subjective differences in representing fuzzy inputs can affect the final outputs. We consider a confined range of forecasted samples in terms of fuzzy membership functions as well as the range of historical forecasting errors in terms of probability density functions. On this basis, th...

The size of wind turbines has been growing fast in recent years with the largest now exceeding 7MW. Furthermore, this trend is expected to continue for the offshore sector. However, this increase in size is accompanied by an increase in the dynamic loading on the structure, in particular, unbalanced loads on the blade and hub. Apart from making wind turbine components more load tolerant, e.g. t...

The ascending trend of photo-voltaic (PV) utilization on a domestic scale in Finland, calls for a technical aspects review of low voltage (LV) networks. This work investigates the technical factors that limit the PV hosting capacity, in realistic case networks, designed relative to different geographical areas of Finland. A Monte Carlo method based analysis was performed, in order to quantify t...

This paper presents an effective rotor current controller for variable-speed stand-alone doubly fed induction generator (DFIG) systems feeding an unbalanced three-phase load. The proposed current controller is developed based on proportional plus two resonant regulators, which are tuned at the positive and negative slip frequencies and implemented in the rotor reference frame without decomposin...

A comparative study of routing techniques is carried out on complicated LEO constellations interconnecting high speed terrestrial networks. Shortest path routing as well as optimal routing (flow deviation) methods are applied for balanced and unbalanced traffic load and for uniform and non uniform distribution of the earth stations. The performance of flow deviation method is proved to be very ...

This work introduces a new asynchronous parallel self-adaptive evolution strategy. An asynchronous scheme is chosen because the load on the processors is usually unbalanced. The proposed algorithm is nonblocking leaving no processor idle at any given time. The motivation and theory for the algorithm is based on the author’s previous analysis of continuous evolution strategies [9] and the reduct...

This paper deals with digital simulation and control of four leg voltage source converter based Dynamic Voltage Restorer(DVR). The control of DVR that injects a voltage in series with a distribution feeder is presented. DVR is a power electronic controller that can protect sensitive loads from disturbances in supply system. It is observed that DVR can regulate the voltage at the load during an ...