by Nguyen Minh Y
Original Research
This paper addresses the operation problem of microgrids under market environments. Considering the flexibility of DG sources in operation as well as the availability of market prices, microgrid operators can improve the profit in electricity markets by properly adjusting DG units in real-time corresponding to the price signal which is updated few-hour ahead. Starting with the basic formulation of unit commitments, the paper derives the optimality condition of DG units, i.e., generation levels for maximizing the profit assuming all units are being On (committed). If the capacity constraint results in an excess of the marginal cost to the locational market price, the unit will be considered to be Off. Taken into account the cost associated with switching On/Off the unit, an economic comparison will determine the optimal decision of whether to turn the unit On/Off or remain its current state. The proposed operation scheme is examined in a case study to illustrate its effectiveness with different scenarios of the market price.
American Journal of Electrical and Electronic Engineering. 2017, 5(5), 189-194. DOI: 10.12691/ajeee-5-5-4
Pub. Date: December 08, 2017
12713 Views2632 Downloads
by Ali Dalir and Hassan Aghaeinia
Original Research
Design of robust transceiver for data rate improvement in interference channel (IC), under imperfect channel state information (CSI), is an important research area. This paper, employs an iterative optimization approach to design algorithm for throughput enhancement in a multi-input multi-output (MIMO) IC. Nodes in the MIMO IC, work in a time division duplex mode, where half of them are equipped with M antennas while the others have Nantennas. In the proposed scheme, each transceiver adjusts its associated filter based on the maximization of the signal-to-interference-plus-noise ratio (SINR). In the time division duplex working mode, the problem utilizes reciprocity of the wireless network. Furthermore, it is investigated how the algorithms proposed by Gomadam et al. can be modified to enhance throughput under CSI error. With the knowledge of error variance Max-SINR is modified. Simulation results present the throughput performances of the proposed algorithms.
American Journal of Electrical and Electronic Engineering. 2017, 5(5), 179-188. DOI: 10.12691/ajeee-5-5-3
Pub. Date: November 30, 2017
11213 Views1586 Downloads
by Aiman Khan and Vivek Pahwa
Original Research
In this paper, a transient study on Isolated Wind-Diesel Hybrid System (IWDHS) of 200 kW has been carried out in MATLAB/SIMULINK environment. The detailed model of synchronous generator coupled to diesel engine, self-excited induction generator and load is studied and considered for analyzing the dynamic behavior of IWDHS. It has been taken into consideration that most of the time; the energy is to be provided by wind turbine in comparison to diesel generator. Instead of a fixed wind speed, the IWDHS is being supplied by variable wind speeds. that are more than its nominal value (10 m/s). This function is accomplished by using a conventional PI controller which regulates the pitch angle of the wind turbine blades during incoming varying gusts of wind. Further the system performance is improved by implementing an ANFIS controller. A controller design process is identified; it consists of generating input-output data pairs to identify the control variables range and initial fuzzy memberships, and then to tune or adapt them using an ANFIS network structure. The control objective was to extract maximum power at varying wind speeds and to limit the power as well as improve settling time at rated value at high wind speeds. The simulations have shown how advantageous an ANFIS based controller is over a conventional PI controller.
American Journal of Electrical and Electronic Engineering. 2017, 5(5), 172-178. DOI: 10.12691/ajeee-5-5-2
Pub. Date: October 07, 2017
15744 Views3137 Downloads1 Likes
by Guchao Xu, Huaiyi Chen, Yixi Chen, Linru Jiang, Rong Ju and Gang Ma
Original Research
The volatility of distributed generation (DG) output power have certain effect on the planning, stability, electric quality, and the relay protection of smart grid. Therefore, traditional grid models are not suitable for the smart grid containing DG. Based on the electrical characteristics of power system, this paper takes the minimization of network loss as the optimization goal to achieve maximum benefit of smart grid. Growing-points are utilized by the OPA model established in this paper to determine the locations and the capabilities of new generation nodes, in order to offer research basis for the planning of smart grid.
American Journal of Electrical and Electronic Engineering. 2017, 5(5), 166-171. DOI: 10.12691/ajeee-5-5-1
Pub. Date: September 28, 2017
14530 Views2908 Downloads