0093-9994 (c) 2018 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/TIA.2018.2860564, IEEE Transactions on Industry Applications 1 A Grid Interactive Permanent Magnet Synchronous Motor Driven Solar Water Pumping System Bhim Singh, Fellow, IEEE and Shadab Murshid, Member IEEE Abstract- This paper deals with an effective power transfer scheme between the a solar photovoltaic (PV) array and single- phase grid, feeding a field-oriented controlled (FOC) permanent magnet synchronous motor (PMSM) drive applied to a water pumping system (WPS). Owing to the intermittency associated with solar (PV) system, the requirement of constant water supply is not possible with standalone system. In order to mitigate this, a grid intergraded WPS is proposed here. The grid integration enables the consumer an uninterrupted operation of water pump irrespective of solar insolation level. Moreover, the PV power can be fed to utility grid when water pumping is not required. To make it possible one voltage source converter (VSC) and one voltage source inverter (VSI) connected to a common DC link, are used for utility grid and PMSM control, respectively. The unit vector template theory is utilized to generate switching pulses for VSC to control the bidirectional power flow between the solar PV system and utility grid through the common DC link. A sensor-less FOC is used to drive the PMSM coupled to water pump. An intermediate stage boost converter is used for extracting optimum power from solar PV array under variable insolation. A perturb and observe algorithm is used for generating the duty ratio for maximum power point (MPP) operation. The applicability of overall system constituting utility grid in conjugation with PV array fed PMSM coupled water pump ensuring bidirectional power flow control with MPP tracking of PV array and abiding the utility grid, IEEE-519 standard for power factor and total harmonic distortion, is simulated in MATLAB/Simulink environment with SIM Power system toolbox and validated on a prototype developed in the laboratory. The system prototype is tested under variable solar insolation and grid abnormalities such as voltage sag and voltage swell. Keywords—PV Array; Utility grid; Voltage source inverter; Voltage source converter; Unit vector template; Field-oriented control; P&O algorithm; Permanent magnet synchronous motor; Water pump; Power quality. I. INTRODUCTION Growing demand of electrical energy due to rapidly increasing population, depletion of conventional energy sources, abrupt climate change, global warming, are the menace of today’s world. The ultimate panacea for dealing these problems appear to be renewable energy [1-2]. Therefore, for the sustainable development and reducing the environmental impact caused by conventional energy sources, government of different countries, have motivated researchers and utility companies, to come forward and integrate the micro-grids based on renewable sources with the main power grid. Owing to its merits of pollution free nature, noiseless operation, abundant availability and reducing installation cost, the solar photovoltaic (PV) energy is one of the best form of renewable energy. With the advancement of semiconductor technology, the steadfast improvement in PV array technology has improved its efficiency and effectiveness. Especially, it has proved to be a vanguard in supplying power to far-flung areas where transmission network cannot reach. Moreover, the benefits of using PV array power include its easy installation, low maintenance requirement and many more. Amongst various sectors where solar PV energy is being utilized, water pumping for domestic as well as irrigation purposes, is seemingly one of the best and economically viable application of PV energy generating system [3-6]. Two types of topologies are mostly used for utilizing PV energy. The conventional two stage topology has first stage to extract the maximum power and the second stage for maintaining the DC link voltage [6-8]. However, a single stage topology is more effective as the first stage DC-DC converter is completely eliminated and thereby the losses associated with it are reduced. Despite this, two stage topology has better control on DC link voltage even at lower insolation level. Moreover, the presence of DC-DC converter eases the burden on VSI as it has to maintain only the power flow to the load [8- 9]. Regardless of the topological differences mentioned above, both of the topologies in standalone mode, suffer from the drawbacks of intermittent power supply as they are largely dependent on climatic conditions, which results in unreliable water pumping. Moreover, water pumping system (WPS) is underutilized during bad weather conditions and is completely shut down during night time. These flaws need to be dealt with, to improve the reliability and to enhance the applicability of the WPS. Initially these limitations have been mitigated by deploying a battery energy storage system (BESS) at the DC link [10]. The BESS keeps on charging and discharging depending upon the availability of solar insolation and ensures full water discharge under all operating conditions [11]. However, the demerits associated with the battery viz. high system complexity, maintenance cost and short service life have bound the researchers to think of some other alternatives. An introduction of a storage tank in association with the pumping system provides one of the possible solution to reduce the dependency on unpredictable weather conditions [12]. Water can be stored in the storage tank when solar insolation is available and no water pumping is required. The stored water can be utilized when shutdown of entire WPS takes place due to unavailability of sunlight. However, the incorporation of storage tank requires larger space and would also increase the system cost. Due to the aforementioned demerits associated with the BESS and storage tank, utility grid connected system is gazed upon as the ultimate solution for PV integrated water pumping. Thus, the service life of the integrated system is enhanced as there is no battery storage mechanism. Many attempts have been made to integrate utility grid to PV array [13-14]. Few of them involve feeding the grid from a PV array first and then pouring power to operate the pump by grid. In [13], the system provides unidirectional power flow. Although it mitigates the intermittency issue, but the unidirectional topology is not capable of feeding the excess power to the grid when pumping is not required. In such a scenario, solar PV array installation is not fully utilized and the consumer has to pay electricity bill for the power consumed from the grid. A bidirectional topology is capable of providing the solution to this issue [14]. Here a phase