A novel controller for a voltage controlled voltage source inverter to mitigation voltage fluctuations measured at the point of common coupling Abdollah Shokri a , Hussain Shareef a , Azah Mohamed a , Masoud Farhoodnea b,⇑ , Hadi Zayandehroodi c a Department of Electrical, Electronic and Systems Engineering, Universiti Kebangsaan Malaysia (UKM), Malaysia b Nano Abzar Pars Co., 168, 2nd Kazemi St., Hemmat Sq., Shokouhieh Industrial Zone, Qom, Iran c Department of Engineering, Kerman Branch, Islamic Azad University, Kerman, Iran article info Article history: Received 13 May 2014 Received in revised form 15 August 2014 Accepted 16 September 2014 Available online 28 September 2014 Keywords: VCVSI Voltage fluctuation Voltage control Phase space Power quality Power electronic abstract One of the most important concerns in manufacturing industries and utilities over the uti- lization of voltage controlled voltage source inverters (VCVSIs) is to generate and maintain a steady sinusoidal output voltage to the critical load which has been the focus of consid- erable research in recent years. VCVSIs output voltage fluctuation may be caused by abrupt or periodic changes of the load current that are significant. The purpose of this paper is to keep the amplitude of the output voltage wave form at the reference level under these con- ditions. The proposed method presents a fast voltage variation detection technique using phase space mathematical method to improve voltage fluctuation. A controller that takes advantage of this detection method is applied to a full bridge inverter to keep the voltage level at the desired point. To investigate the efficiency and accuracy of the proposed con- troller, a system is modeled using Matlab/Simulink and the results is compared with open- loop and RMS controllers. The simulation results approve the capability of the proposed controller to provide a sinusoidal output voltage and mitigate voltage fluctuation to a con- siderable level by using phase space method. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction Voltage controlled voltage source inverters (VCVSIs) are extensively used in industrial, military and marine applica- tions, power quality compensators, renewable energy technologies and power supplies [1]. They are located at the heart of all applications that require converting a direct voltage to an alternating one. Accordingly, designing an efficient and robust VCVSI is momentous, especially in some fields such as renewable-energy applications and remote areas where the disturbance in inverter output will cause course inconvenience and the available power will be restricted. One of the most important concerns in manufacturing industries and utilities over the utilization of VCVSIs is the voltage variation that may cause disruption in the pro- cessing plant, causing hours down. For example a study in South Africa estimates that 891 min of down-time in 1996 due to such of voltage variations caused around $2 million turnover loss for that year [2]. Voltage variation can be described as repetitive or random fluctuation of the volt- age envelope due to the sudden changes in the power drawn by a load. The characteristics of the voltage varia- tions depend on the load type and capacity, it may happen when the loads draw or inject currents with significant http://dx.doi.org/10.1016/j.measurement.2014.09.042 0263-2241/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel: +98 9197955647. E-mail address: frahoodnea_masoud@yahoo.com (M. Farhoodnea). Measurement 59 (2015) 216–226 Contents lists available at ScienceDirect Measurement journal homepage: www.elsevier.com/locate/measurement