1551-3203 (c) 2016 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information. This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI 10.1109/TII.2017.2677462, IEEE Transactions on Industrial Informatics > REPLACE THIS LINE WITH YOUR PAPER IDENTIFICATION NUMBER (DOUBLE-CLICK HERE TO EDIT) < 1 Abstract—This paper presents an experimental implementation of a standalone microgrid topology based on a single voltage source converter (VSC) and brushless generators. The microgrid system is energised with different renewable energy sources namely wind and solar PV array. However, a diesel generator (DG) set and a battery energy storage system (BESS) are also used to maintain the reliability of the system. The proposed topology has the advantage of reduced switching devices and simple control. The implemented topology has DG set as an AC source. The wind generator and the solar PV array are DC sources which are connected to the DC link of the VSC. The BESS is also used at the DC link to facilitate the instantaneous power balance under dynamic conditions. Along with the system integration, the VSC also has the capability to mitigate the power quality problems such as harmonic currents, load balancing and voltage regulation. A wide variety of test results are presented to demonstrate all the features of the proposed system. Index Terms— Brushless Generator, Composite Observer, Power Quality, Standalone Microgrid, Voltage Regulation, Voltage Source Converter I. INTRODUCTION HERE are many locations in the world where the small localities are developed far away from the well-developed societies. It is technically and economically difficult to setup a transmission system to make electricity available there due to the cost incurred, the problems related to grounding of the transmission tower at hilly areas and ROW (Right of Way) problems due to forests in between. However on the other hand, these areas have abundance of natural resources like solar energy, wind, hydro etc. Due to uncertain nature of all these renewable energy sources, a small self-sustaining supply system cannot be established which can supply the loads continuously. To make the system self-sustaining, some reliable sources are required. Therefore, generally a diesel generator is used at these sites. To account for randomness of the natural resources, a full rating diesel generator is a costly option. Some energy storage device can be employed there, which reduces the diesel generator rating and considerable fuel consumption. As described earlier, since the system is setup at a remote area, the brushless generators [1] are used to avoid the Krishan Kant was with EE Department, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India. He is now with Exicom Telesystems Limited, HR, 122015, India (e-mail: krishan.kant@exicom.in). Chinmay Jain was with EE Department Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India. He is now with Shakti Pumps India Ltd, MP, 454774, India. Bhim Singh is with the EE Department, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India. maintenance as much as possible. The proposed topology in this paper includes solar PV array and wind energy as natural resources. A substantial literature is available for different topologies, control, operational aspects, power electronics of the wind and solar PV systems [2-5]. Authors have proposed many topologies, control algorithms and operation strategies for the microgrid system with many energy sources. Like DFIGs (Doubly Fed Induction Generators) are used for wind and diesel based system [6], where the controller is optimizing the fuel consumption and regulating the voltage and frequency of the system with maximum available power extraction from wind. Different operating strategies to include wind power in a diesel based system to save fuel and to reduce the overall cost of the system is proposed in [7,8]. A time frame based control algorithm is proposed in [9] for a wind-diesel system with an energy storage. In this paper, authors have proposed an ESS (Energy Storage System) to account for wind randomness and fuel cost. A standalone hybrid wind-solar system with engine generator and a battery is proposed in [10], where the operational aspects and topology are described. The proposed topology has six VSCs to integrate the complete system. Lin et. al. [11] have proposed a solar and diesel–wind hybrid generation system with BESS, in which synchronous generator is used for a diesel generator which requires AVR (Automatic Voltage Regulator) and speed governor for voltage and frequency regulation. Yogianto et. al. [12] have proposed different configurations of a hybrid system using solar PV array, wind and diesel systems. An optimal operation of solar PV/diesel hybrid system without storage is described in [13]. With the given load profile of an area for whole day, size and scheduling of the generator are performed to maximize the generator efficiency. Similarly to reduce the battery size and to increase efficiency of the system, an ultra-capacitor is used with the battery to exchange power during dynamics and the battery is used to supply under sustained load generator power mismatch [14]. Along with these different topologies and control strategies, other studies are also reported in the literature. Simulation studies are carried out for a microgrid system with many sources and energy storage devices with different controllers to regulate frequency of the system [15]. Different generators are used with the diesel engine and the studies are performed with diesel, PV and diesel-PV mixed generation. Moreover, the short circuit studies are performed on the system by Bonanno et. al[16]. Reliability evaluation of a wind-diesel-battery based system is reported by Liu et.al. [17], where wind energy conversion system reliability is obtained taking into consideration the wind fluctuations and component failure. Moreover, the reliability analysis of the A Hybrid Diesel-Wind-PV based Energy Generation System with Brushless Generators Krishan Kant, Chinmay Jain, Member, IEEE and Bhim Singh, Fellow, IEEE T