Intelligent Control of Wind/ Photovoltaic Microgrid Information Fusion

Abstract

Copyright © 2017 Universitas Ahmad Dahlan. All rights reserved. IntroductionAs a new alternative energy, small wind and solar complementary generation system is always operated in Micro-grid island mode, also as a distributed generation technology used in group buildings [1]. The use of wind and solar complementary power can solve problems to a certain extent of environmental pollution and energy exhaust caused by the use of traditional energy sources, but the unique uncertainty and randomness of wind and solar generation power create major obstacles to the power generation and supply demand management [2], which show inherent shortages of centralized control or distributed control, wind and photovoltaic Micro-grid system is difficult to provide continuous and stable energy output [3]. In general, Wind/ Photovoltaic Micro-grid storage technology appeared in literatures are mostly focused on single function of maximum power tracking or analysis of battery capacity or operation method. Few are focused on proactive energy storage planning from the angle of the multi-objective control, such as battery charge and discharge protection, reliable power supply of Micro-grid load and peak load shifting, so as to achieve flexible and efficient control.There is hybrid systems appeared in existing literatures integrated with energy storage device. However, due to the battery own characteristics [4], system cost and efficiency of wind and solar power generation are affected [5]. To improve the efficiency of the system, mixed control structure is used under reliability constraints [6]. By predicting the wind speed and solar radiation per-hour, thus the rational capacity allocation of hybrid power system is done, so improving reliability and reducing cost [7]. The energy storage system is undoubted the preferred mode of distributed generation of energy regulation, the key technology related closely with battery life is the battery charge and discharge methods and strategies [8,9]. Charge and discharge management of battery is essential for reliable and stable operation of wind and solar

Stochastic control for optimal power flow in islanded microgrid

“…This method is based on Kushner's approach [25]. By adopting the algorithm in [28], the HJB equation (15) which includes the gradient of value function of V i (t, X) can be solved. Let X > 0 and t > 0 denote the length of the finite difference interval of the variable X and t respectively.…”

“…For the load flow problem which is typically formulated as a set of non-linear equations as functions of bus voltages has taken some advantage. The contributions of optimal power flow are considred in [14], the control of MG in [15], and quality of power (power factor, total harmonic distortion) as in [16]. Stochastic demand has been developed and presented in [17]- [19], those authors used stochastic, fuzzy, and probability programming techniques to model the uncertainties.…”

VRLA battery state of health estimation based on charging time

“…The battery damage may occur due to some causes, such as overcharging, discharging, and even the battery life-cycle limits [10]. A diagnostic process is very important to maintain the proper operation of a battery.…”