Minimization of Cogging Torque Based on Different Shape of Anti-Notch Method Herlina Electrical Department Universitas Indonesia Depok, Indonesia Electrical Department Universitas Sriwijaya, Palembang, South Sumatera Rudy Setiabudy Electrical Department Engineering Faculty Universitas Indonesia Depok, Indonesia Uno Bintang Sudibyo Electrical Department Engineering Faculty Universitas Indonesia Depok, Indonesia Abstract—A Permanent Magnet Synchronous Generator (PMSG), part of a wind turbine, has a function to convert mechanical energy into electrical energy. To rotate the first cycle, the generator is blocked by an opponent torque called detent torque/unload torque or cogging torque . This study aim to reduce the cogging torque, modifying teeth formation on the surface of stator teeth. Simulation of the model used Finite Element Magnetic Method (FEMM) 4.2 software. From the simulation results of the reference and proposed models showed that half cylinder shape of the anti-notch (1 st model) reduce cogging torque until 93.42% positive peak and 97.75% of negative peak from the reference model. Keywords— Shape, Anti Notch, Reduction, Cogging Torque I. INTRODUCTION The shortage of power produced by conventional power plants aware to search for alternative power plants. One of the alternative is the wind power plant. The main component of wind power plant is the generator. Nowadays, a permanent magnet synchronous generator (PMSG), considered to be more suitable for wind turbine systems to be applied in rural and remote based areas [1]. This is based on the advantages of this type of generator that does not require leading voltage obtained from the main power and battery for initial excitation (compared with induction generator type). The problems arise when choosing a PMSG is highly cost to purchase a permanent magnet material, the size of the generator are large, heavy, complicated in controls, and the arising of cogging torque [2]. Cogging torque arises due to the interaction between the slots on the stator with the electromagnetic field generated by the permanent magnets on the rotor. The greater the cogging torque, the rotation of the rotor will be hampered and heavier, and the generator does not produce electricity when wind speed is low. A number of cogging torque methods have been developed to minimize the cogging torque. A notching method tried to increase the amount of magnetic interaction between the permanent magnet on the rotor with the teeth and the dummy slot. The slot is not as deep as the stator slot to put the winding but its purpose is mitigating the cogging torque. Yusifar. F, et al [3] simulated the reduction of cogging torque with variations of the number of slot and teeth in the stator, combination of both, and then using the "notching" method. The type of the motor is BLDC motor, surface mounted, 12 slots 8 poles and 10 slots 8 poles. The results obtained the 10 slots 8 pole motor got a smaller cogging torque 50%, (close to 0.5 Nm) is smaller than the design of 12 slots 8 pole (close to 1 Nm). This is in accordance with the statement that a large factor of goodness will lead to greater cogging torque generated. From the results of research, using notch method is not very influential to reduce the cogging torque. Hong Uk Kim [5], optimized the notch shape of IPMSM rotor surface to reduce the cogging torque using the Particle Swarm Optimization (PSO) method. The cogging torque reduction namely 73.27%. Other studies using notching method proposed by Cheng Yu et al [4] is by designed permanent magnet motor with a radial flux and with a notch in the permanent magnet and in the stator teeth. Permanent magnet material used is the type of rare earth magnet (REM), Cheng Yu examined the relationship between the width and the depth of the notch on REM, stator teeth. From this research obtained that variation of width and depth of a notch on REM decrease the cogging torque in PM-1 by about 62%. For variations notch in the stator teeth, the design of the ST-2 has a torque reduction of 90%. To design a combination of notches in the stator and in REM, a decrease of 62.8% coggingnya torque and REM consumption was reduced by 6.7% if designed without notch. This research aims to reduce the cogging torque by using anti notch. There are three shape of anti-notch to be investigated, namely a square, half cylinder and triangular are placed on the surface of the stator teeth. Proc. of 2016 3 rd Int. Conf. on Information Tech., Computer, and Electrical Engineering (ICITACEE), Oct 19-21 st , 2016, Semarang, Indonesia 978-1-5090-0890-2/16/$31.00 c 2016 IEEE 160