IJISET - International Journal of Innovative Science, Engineering & Technology, Vol. 8 Issue 7, July 2021 ISSN (Online) 2348 – 7968 | Impact Factor (2020) – 6.72 www.ijiset.com Study of the torque impact on the Permanent Magnet Synchronous Generator voltages output for a vertical axis tidal turbine Télesphore Randriamaitso 1, * , Ruffin Manasina 2 , F. Philibert Andriniriniaimalaza 2 and Jean Marie Razafimahenina 1 1 Université d’Antsiranana, Ecole Doctorale Thématique Energies Renouvelables et Environnement (EDT ENRE), BP 0, Antsiranana (201), Madagascar 2 Université de Mahajanga, Institut Supérieur des Sciences et Technologies de Mahajanga, Majunga-be, Majunga (401), Madagascar _________________ * Correspondance, email : rmaitsotelesphore@gmail.com Abstract The objective of this paper is to observe the effect of the oscillating torque provided by a vertical axis tidal turbine on the voltages output of PMSG when the tidal turbine is equipped or not with a regulation system. In this study, the turbine torque is determined by the DMST model. The PMSG Park model is used. In addition, the chosen control system includes a PWM rectifier, PI controllers and MPPT with optimal TSR. The latter considers the fixed reference rotational speed at each flow speed. The simulation of the turbine and PMSG assembly was realized for the turbine operating at maximum average efficiency with a flow of 1.5 meter per second and turbine of 0.455 meter turbine radius, 0.824 meter blade height and blade profile NACA0018. Without a control system, the PMSG supplies, by supplying a resistive and inductive load, voltages with more undulating amplitudes compared to the tidal turbine equipped with a control system. The voltages output from PMSG can be improved by looking for the reference rotational speed as a variable to minimize the error between the measured rotational speed and the reference one. Keywords: vertical axis tidal turbine, PMSG, DMST, Control, torque, voltages. 1. Introduction Currently, the energy we use on a daily basis comes mainly from usual sources such as fossil fuels (oil, gas, coal) [1]. Their major drawback lies in the very near exhaustion and the emission of gases which pollute the atmosphere enormously. Faced with the constraints posed by fossil fuels, the best possible solution would be to use renewable energies, which have the advantage of being abundant and inexhaustible in the millennia to come. It is in this situation that tidal power presents itself today as one of the most interesting renewable energy sources, thanks to its enormous global potential estimated at a power of 100 GW [2], which represents a considerable deposit. Tidal turbines are turbines that recover kinetic energy from river or sea currents. They are somewhere equivalent to wind turbines. To produce energy, tidal turbines will need a current speed greater than 1m / s on average [3]. The Permanent Magnet Synchronous Generator (PMSG) is widely used in tidal turbine applications, in particular, because of its good conversion efficiency (close to 99% compared to the asynchronous Generator [2]. The synchronous machine allows operation as well at low speed (direct drive system) than at high speed (indirect drive system), so it can be coupled or not with a speed multiplier [4].Two main categories of tidal turbines exist: those with axis of horizontal rotation and those with vertical axis of rotation. This study considers a vertical axis tidal turbine equipped a PMSG with direct drive. The GSAP transforms mechanical energy into electrical energy. Studies show that the vertical turbine provides a pulsating torque [5], [6], [7], [8]. So, our objective is to observe by simulation, the impact of the oscillation of the torque of the vertical axis turbine on the GSAP output voltage. The simulation requires the modeling of the tidal turbine system without or with a control system. The latter uses the tip speed ratio (TSR) MPPT or (MPPT with optimal TSR) method [9] with PI corrector [10], [11] to control the turbine and the vector control of the AP associated with PI corrector and Pulse With Modulation (PWM) rectifier based on bipolar transistor (IGBT) [12], [13] [14]. Then, the turbine torque is determined by the Double Multiple Stream Tube (DMST) Model [15], [16], [17], [18]. Finally, the PARK model of the PMSG [19], [20] is used. 537