Majlesi Journal of Energy Management
Volume:7 Issue: 2, Jun 2018

Recently, the cooperation of energy storage systems and demand response programs in providing efficient energy management scheme have attracted enormous attention among researches. Considering the high capital cost of energy storage systems, the optimal economically sizing and sitting in distribution networks is an ineluctable task. In this paper, the optimal allocation of energy storage units in the presence of demand response programs has been studied. This paper is the updated version of our conference paper, in which the participation of responsive demands in both energy and reserve markets via direct and indirect participation is considered. Also, the block order participation modeling for demand response aggregator is formulated. The optimization problem is solved using GAMS optimization software. The results show that integration of demand response programs and energy storage systems in distribution networks can decrease system operation’s annual cost by about 10%.

A direct power control (DPC) drive allows independent and direct command of reactive power linkage and stator active power by the selection of optimum inverter switching tables (STs) of an induction generator (IG). There is no need for any complex conversion of voltage or current. However, each vector selected from the ST can not produce the required accurate voltage vector to provide the desired active and reactive powers. This results in the production of ripples in the reactive power as well as active power waveforms. In this study, we propose a technique to minimize active and reactive powers fluctuations. In this proposed strategies, the circular flux vector is divided into 12 sectors of 30 degrees and is compared to each other. Switching table is based on neural networks controller. The proposed strategies of 12 sectors DPC strategy are simulated and the comparison of their performances is presented.

Basic Reactive power compensation is provided by capacitor banks and active power compensation is provided by Distributed Generators (DGs) like, Solar, Wind and Mini-hydro power plants.  For obtaining optimal placement of Mini Hydro Power Plants and capacitor banks Water Cycle Algorithm (WCA) is intended. The optimal sizes of Capacitors and DGs chosen are of continuous sizes.   33-Bus and 69-Bus radial  distribution systems are chosen for testing this algorithm to identify potential locations and sizes of Mini hydro and capacitors.   It is found that with the proposed WCA, maximum loss reduction of  79 % is obtained for 33 Bus system and 83.6% for 69 Bus system.  Cost analysis is also presented with three different load levels along with above DGs and Capacitors.  In addition to cost analysis, for the benefit of environment carbon emissions are also calculated and found that there is a reduction of 4,034.57 tons of CO2 emission per year on 33 bus system and 4,607.88 tons of CO2 emission per year on 69 bus system.  It is proved that WCA offers highest loss reduction with minimum sizes of DGs and capacitors compared to any other algorithm available in the literature.  The WCA is easy to implement and the search process is methodic.

This article proposes a new modulation strategy that can minimize the stator current distortion and powers ripples for a doubly fed induction generator (DFIG) controlled by neuro-second order sliding mode controller (NSOSMC). The proposed five-level space vector modulation (5L-SVM) strategy is a hybrid technique which consists of 5L-SVM strategy and the intelligence technique (neural networks (NNs) and Fuzzy logic controller (FLC)). The former provides low current distortion and reduce powers ripples. On the other hand, the NSOSMC method with classical 5L-SVM strategy gives more powers ripples and harmonic distortion of stator current. For the proposed techniques, in the simulation region of neural space vector modulation (NSVM) technique, fuzzy space vector modulation (FSVM) is used to reduce the stator current distortion and powers ripples. Comparison of simulation results derived from a Matlab/Simulink software based controlled inverter is included. The work demonstrates that using the proposed hybrid 5L-SVM strategy, the three-phase current signals of the inverter can be reconstructed even under very low modulation index range while providing a low current harmonic distortion of the five-level inverter output.