International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 07 Issue: 02 | Feb 2020 www.irjet.net p-ISSN: 2395-0072 © 2020, IRJET | Impact Factor value: 7.34 | ISO 9001:2008 Certified Journal | Page 317 Analysis of Open Loop Distribution Static Compensator for Improving Power Quality Rinkesh G. Satpute 1 , Yashashri B. Deshmukh 2 , Poonam A. Shende 3 Suryakant B. Morey 4 1,2,3,4 Assistant Professor, Dept. of Electrical Engineering, DMIETR, Wardha, Maharashtra, India. ---------------------------------------------------------------------***---------------------------------------------------------------------- Abstract - This paper presents Distribution Static Compensator (D-STATCOM) modeled in the MATLAB SIMULINK toolbox for the mitigation of the power quality issues in the distribution system. DSTATCOM is one of the custom power device used in distribution system for power conditioning. DSTATCOM is developed for the compensating reactive power demanded by non-linear and unbalanced load. Also power factor of the source is improved and the Total Harmonic Distortion in the source currents is reduced. DSTATCOM can correct voltage sag, swell, unbalance by injecting the reactive current into the system. Instantaneous reactive power theory is used for obtaining reference source current for controlling DSTATCOM. The performance of the DSTATCOM for unbalanced and nonlinear load is demonstrated with the MATLAB simulation results. Key Words: Distribution Static Compensator (D- STATCOM); Power Quality; Battery energy storage system (BESS); Total Harmonic Distortion (THD). 1. INTRODUCTION Utility and customer-side disturbances result in terminal voltage fluctuations, transients, and waveform distortions on the electric grid. Just as flexible ac transmission systems (FACTS) controllers permit to improve the reliability and quality of transmission systems, these devices can be used in the distribution level with comparable benefits for bringing solutions to a wide range of problems. In this sense, FACTS based power electronic controllers for distribution systems, namely custom power devices, are able to enhance the reliability and quality of power that is delivered to customers. A distribution static compensator or DSTATCOM is a fast response, solid-state power controller that provides flexible voltage control at the point of connection to the utility distribution feeder for power quality (PQ) improvements. The primary aims of a shunt compensator in a distribution system are to cancel or suppress the effect of poor load power factor such that the current drawn from the source has a near unity power factor, the effect of harmonic contents in loads such that current drawn from the source is nearly sinusoidal, the dc offset in loads such that the current drawn from the source has no offset, the effect of unbalanced loads such that the current drawn from the source is balanced. It can exchange both active and reactive power with the distribution system by varying the amplitude and phase angle of the converter voltage with respect to the line terminal voltage, if an energy storage system (ESS) is included into the dc bus. The result is a controlled current flow through the tie reactance between the DSTATCOM and the distribution network. This enables the DSTATCOM to mitigate voltage fluctuations and to correct the power factor of weak distribution systems in instantaneous real-time. This paper discusses the dynamic performance of a DSTATCOM with ESS for improving the power quality of distribution systems. Modelling approaches are proposed, including a detailed modelling of the DSTATCOM. 1.1 Modeling of The STATCOM A DSTATCOM consists of a three-phase voltage source inverter shunt-connected to the distribution network by means of a coupling transformer, as depicted in Fig. 1. Its topology allows the device to generate a set of three almost sinusoidal voltages at the fundamental frequency, with controllable amplitude and phase angle. In general, the DSTATCOM can be utilized for providing voltage regulation, power factor correction, harmonics compensation and load levelling. The addition of energy storage through an appropriate interface to the power custom device leads to a more flexible integrated controller. The ability of the DSTATCOM/ESS of supplying effectively extra active power allows expanding its compensating actions, reducing transmission losses and enhancing the operation of the electric grid. Various types of energy storage technologies can be incorporated into the dc bus of the DSTATCOM, namely superconducting magnetic energy storage (SMES), super capacitors (SC), flywheels and battery energy storage systems (BESS), among others. However, lead-acid batteries offer a more economical solution for applications in the distribution level that require small devices for supplying power for short periods of time and intermittently. Moreover, BESS can be directly added to the dc bus of the inverter, thus avoiding the necessity of an extra coupling interface and thus reducing investment costs to illustrate the functioning of shunt compensator. The use of power electronics based loads such as variable speed drive, inverter-based air conditioning, distributed generation and storage system, personal electronics and electric vehicle has given rise in issue of power quality. This Paper proposed a D-STATCOM for harmonic current mitigation and power factor correction, which result due to the use of non-linear loads in the modern EDN.