International Journal of Scientific & Engineering Research, Volume 6, Issue 10, October ISSN

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1 International Journal of Scientific & Engineering Research, Volume 6, Issue 10, October ISSN Magnitude reduction of stator current in LD Motor Using HallStator urrent ontrol Strategy Hitesh hoyal¹, R.K Gupta² Electrical Engineering Department, Suresh Gyan Vihar School of Engineering and Technology Jaipur, Rajasthan, India¹, Electrical Engineering Department, Suresh Gyan Vihar School of Engineering and Technology Jaipur, Rajasthan, India², 2 rkg90000@gmail.com STRT In the current past, ariable speed dries hae grown in many applications as automobile industries, domestic appliances etc. The electronics deices are mostly built up to presere the energy consumption of arious deices. This increase to the growth in rushless D motor LD motor and the LD motor improes different factors ranging from Haing High dynamic response, Haing Higher efficiency, low weight, compact construction, Long operating life, Noiseless operation, Higher speed ranges instead of other motors. The LD motor can operate as a choice for traditional motors like induction and switched reluctance motors. In this paper the conentional control strategy which is Hall sensor output control strategy is implemented using the HallStator current output control strategy. It is obsered that the magnitude of stator current is reduced using the HallStator current output control strategy so for the same operating condition and speed the LD motor is taking less current hence losses due to current is less when compared with conentional control strategy. The simulation of LD motor is done using MTL R2009b. Keywords: PI controller, LD motor, HallStator current control, Hall effect sensor, feedback loop, torque ripple, speed. 1 INTRODUTION Smooth torque profile must be produced to get improed operation. In the conentional brushed D motor, the brushed motors require more maintenance. To oercome this problem, brush assembly is replaced with electronic switching. The brushless D motors hae rotor with permanent magnets, connected with switching deices. The LDM is mostly used motors in industry, Medical, utomoties, instrumentations. This types of motor do not hae brushes and commutator because LD motors use electronic commutation based on rotor position information. These are ery useful where weight and space is a problem. The LD motor has seeral adantages than brushed motor. There are few adantages of LD motor: higher speed, Higher efficiency, low weight, compact construction, Long life. The LD motor has main drawback of torque ripples. The current takes some time to increase or decrease to the steady state condition in the actual LD motors, because current is affected by resistance and inductance of the winding [1]. Therefore the ripples in current occur due to effect of motor inductance. So further torque ripples are directly affected by current ripples if back EMF is a trapezoidal waeform. 2 PRINIPLE OF OPERTION In brushed motor, commutator and the brushes are used to reerse the current polarity while in LDM polarity of current is reersed by oltage source inerter which is controlled according to rotor position of the motor. The absence of commutator gies good benefit when talking about higher reliability. Due to the commutator and brushes, D motor is unable to produce maximum speed. Hence the LDM is used where more speed is required because there is no friction [2]. Further the positioning of rotor is experienced to line up supplied oltage with backemf. In this situation LDM acts like a D motor. 3 TORQUE/SPEED HRTERISTIS LDM Torque/speed characteristics is in fig.1. LD motor is defined by using two torque parameters, max & rating torque. LDM can be used upto rating torque during continuous operation 2015

2 International Journal of Scientific & Engineering Research, Volume 6, Issue 10, October ISSN [3]. When LDM is operating at rated speed then torque remains constant. The LDM can rotate upto highest speed. higher torque can be deliered by the motor, maximum upto the peak torque, when motor follows the speed torque cure. Fig: 1 Torquespeed characteristic Fig: 3 sinusoidal back EMF waeform 4 LD MOTOR 5 TORQUE RIPPLE SOURES IN LD MOTOR Magnets are placed on the face of rotor that proides lifelong field excitation to the LD motor. The torque ripple in LDM is classified in three In lowcost LDM Ferrite and ceramic magnetic categories () Motor s nature, () Motor s structure material are the superior choices [6]. These magnets and () Motor s control. exist with reminisce of 0.38 T. Ndy.Fe.o material uses for particular purposes. Fault current can 5.1 Motor s nature demagnetize the Magnets like shortcircuit current Torque ripple linked with LDM nature pertain created because of inerter fault. that's why, caring to the physical property & also factor of the motor s determination is generally used for inerter and constructed stuff [5]. etter performance leads by manages electronically to bind magnitude of superior choice of materials. armature s current for a secure quantity [4]. The four poles in LD motor is the superior choice and it also 5.2Motor structure hae six or eight poles. LDM has trapezoidal backemf. This is related to design parameters of motor, like shape and dimensions. These parameters are cautious deliberation which leads to good performance design. 5.3 Motor control: For minimization of torque ripples seeral techniques hae been utilized. 6 SIMULTION ND RESULTS Fig: 2 Trapezoidal back EMF waeform The Hallstator current control strategy of three phase oltage source inerter fed LD motor is simulated using MTL/SIMULINK for the alidation of work and results are presented. Two control strategies are used to generate the gate signals: 1. Using hall effect sensor output 2. Using comparision of hall sensor and stator current output 2015

3 International Journal of Scientific & Engineering Research, Volume 6, Issue 10, October ISSN Using hall effect sensor output The output of measurements for the LD motor is gien to the bus selector. The bus selector is used to gie the required measured alue from LD motor as separate signal. There are two bus selectors used. First bus selector proides three hall sensor sensed signals and Second bus selector gies four measured alues as stator curent, stator back emf, rotor speed, electromagnetic torque. The scope is used to see the waeforms of the measured alue. increases up to 19 amp and decreases up to 10 amp. Further it is 0.4amp in interal from 0.04 to 0.1 and becomes steady state stator current at 3 amp after 0.1 sec as shown in aboe fig 5. Discrete, Ts = 1e005 s powergui PIontroller s Fig: 6 rotor speed The rotor speed is obtained for 4sec simulation time, at the start rotor speed rises in interal from 0 to 0.04sec and it becomes constant for ery small period in interal (0.05, 0.1). Then speed decreases for ery small period from 0.1 to 0.13sec, after 0.13sec the rotor speed becomes constant at 3000 rpm. hall Step <Stator current is_a ()> g Tm <Stator back EMF e_a (V)> m Krad to rpm Scope1 <Rotor speed wm (rad/s)> Scope3 Permanent Magnet <Electromagnetic torque Te (N*m)> Synchronous Machine Scope2 Gates Scope9 Out In Scope10 Scope Fig: 7 electromagnetic torque waeform using hall sensor control strategy Fig: 4 simulation with hall effect sensor output Fig: 5 stator current of LD motor for phase a using hall sensor control strategy When three phase supply is applied to the stator winding then maximum starting stator current The electromagnetic torque is obtained for 0.5sec simulation time. The maximum starting electromagnetic torque is 27 Nm. s clear from waeform fig.7 the torque starts decreasing from to 0.04 time interal and deelops a torque of 0.5 Nm at no load condition. The electromagnetic torque becomes continue fluctuating after 0.1 sec at 4.2 Nm. 2 Using hallstator current control strategy In this control strategy the hall effect sensor signal and three phase stator current signal are compared to generate the gate signal. For this purpose decoded hall effect sensor signal is transfered from the decoder block using GOTO and FROM block as hall1, hall2, hall3 signals. Mux is used to combine these signals which gies only a single output signal. Scope shows the output waeform of the decoded signal. Further this signal is fed to the positie terminal of the sum. Modulated hallstator current 2015

4 International Journal of Scientific & Engineering Research, Volume 6, Issue 10, October ISSN output signal then generates gate signal for the oltage source inerter. When the gate signal is applied to gate terminal of the oltage source ineter, the oltage source inerter gies controlled proper phase sequences for the LD motor. hall control strategy; here the magnitude of stator current is 2.5amps as shown in aboe fig 9. Gates Discrete, Ts = 1e005 s powergui Scope10 In Scope Fig: 10 rotor speed PI s g Step Tm m Permanent Magnet Synchronous Machine Scope9 <Stator current is_a ()> <Stator back EMF e_a (V)> Scope1 Krad to rpm <Rotor speed wm (rad/s)> <Electromagnetic torque Te (N*m)> Scope3 Scope2 The rotor speed is obtained for 4sec simulation time, at the start rotor speed rises in interal from 0 to The rotor speed gets constant for (0.03, 0.05) interal and speed decreases for small period from 0.05 to 0.08, after 0.08 the rotor speed becomes constant at 3000 rpm. 2 hall 2 3 hall 3 1 hall1 hallstator current Scope4 PI12 Scope5 Scope7 Scope6 Scope8 hallstator out IN Fig: 11 electromagnetic torque waeform using hallstator current control strategy Fig: 8 simulation with Hallstator current control strategy Fig: 9 stator current of LD motor for phase a using hall stator current control strategy When hallstator current control strategy is applied and when three phase supply is applied to the stator winding then maximum starting stator current increases up to 15 amp and decreases up to 12amp. Further stator current is 0.5amp in interal from 0.04 to 0.1 and becomes steady state stator current at 2.5amp after 0.1 sec. It is obsered that the magnitude of stator current is less as compare to the conentional The electromagnetic torque is obtained for 4sec simulation time. The maximum starting electromagnetic torque is 3.88 Nm. s clear from waeform shown in fig. 11 at the starting situation the torque gets fluctuating from 0 to 0.03 time interal and becomes constant at 2.67Nm after 0.03 and remains constant until The electromagnetic torque becomes continue fluctuating after sec at 3.88 Nm. 7 ONPRISION The fig. 12 shows the comparison between the magnitude of stator current with conentional control and hallstator current control strategy. It is obsered that the magnitude of stator current is less as 2.5amp with hallstator current control strategy 2015

5 International Journal of Scientific & Engineering Research, Volume 6, Issue 10, October ISSN losses due to current is less when compared with conentional control strategy. REFERENES [1] Purna handra Rao, Y.P.obulesh Performance Improement of LD Motor with Hysteresis urrent ontroller, ijareeie, Vol. 2, Issue 12, pp , December [2] Kiran George, Sija Gopinathan, Shinoy K.S. omparison of Three Phase and Fie Phase LD Motor, ijareeie,vol. 2, pp , Special Issue 1, December [3] Mohamed.. Enany, Hamed. M. Elshewy, Fathy. E. bdelkader rushless D Motor Performance Improement through Switchon and Switchoff ngles ontrol, airo Fig. 12 explains the comparison between the magnitude of electromagnetic torque ripples it is obsered that the magnitude of electromagnetic torque decreases in hallstator current control when compared with conentional control Uniersity, pp December 1921, [4] ikram Das, Suamit hakraborty, banishwar hakraborti, Prabir Ranjan Kasari Performance nalysis of LD Motor Using asic Switching onerters, ijitee, Volume2, Issue1, pp 1114, December [5] Sharmila Kumari.M, Sumathi.V, Viekanandan S, Shobana S PERFORMNE IMPROVEMENT OF LD MOTOR USING FUZZY LOGI ONTROLLER, ijser, Volume 5, Issue 4, pp , pril2014. [6] Jainesh M. Patel, Hitesh V. Hiraniya, Mula Rathod Simulation and nalysis of rushless D Motor ased on Sinusoidal PWM ontrol, ijireeice, Vol. 2, Issue 3, pp , March Fig: 13 comparison of speed and electromagnetic torque 8 ONLUSION Permanentmagnet brushless dc motors are extra broadly used in highperformance appliances due to the better speed with respect to torque characteristics, Haing High dynamic response, Haing Higher efficiency, low weight, compact construction, Long operating life, Noiseless operation, Higher speed ranges instead of other motors. In this paper the conentional control strategy which is Hall sensor output control strategy is implemented using the HallStator current output control strategy. It is obsered that the magnitude of stator current is reduced using the HallStator current output control strategy so for the same operating condition and speed the LD motor is taking less current hence 2015