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  1. 1. Dr. M.Sridhar / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 3, Issue 1, January -February 2013, pp.473-481 A Speed Control Of Pmbldcm Drive Using Single Stage Pfc Half Bridge Converter Dr. M.Sridhar, H.O.D, Sayed Baji Shaik Department of EEE, GIET, RAJAHMUNDRYAbstract In this paper, a buck half-bridge DC- conditioners mostly have a single-phaseDC converter is used as a single-stage power induction motor to drive the compressor infactor correction (PFC) converter for feeding „on/off‟ control mode. This results in increaseda voltage source inverter (VSI) based losses due to frequent „on/off‟ operation withpermanent magnet brushless DC motor increased mechanical and electrical stresses on(PMBLDCM) drive. The front end of this PFC the motor, thereby poor efficiency andconverter is a diode bridge rectifier (DBR) fed reduced life of the motor. Moreover, thefrom single-phase AC mains. The temperature of the air conditioned zone isPMBLDCM is used to drive a compressor regulated in a hysteresis band. Therefore, improvedload of an air conditioner through a three- efficiency of the Air-Con system will certainlyphase VSI fed from a controlled DC link reduce the cost of living and energy demand tovoltage. The speed of the compressor is cope-up with ever increasing power crisis.controlled to achieve energy conservation using A PMBLDCM which is a kind of three-a concept of the voltage control at DC link phase synchronous motor with permanentproportional to the desired speed of the magnets (PMs) on the rotor and trapezoidalPMBLDCM. Therefore the VSI is operated back EMF waveform, operates on electroniconly as an electronic commutator of the commutation accomplished by solid statePMBLDCM. The stator current of the switches. It is powered through a three-phasePMBLDCM during step change of reference voltage source inverter (VSI) which is fed fromspeed is controlled by a rate limiter for the single-phase AC supply using a diode bridgereference voltage at DC link. The proposed rectifier (DBR) followed by smoothening DCPMBLDCM drive with voltage control based link capacitor. The compressor exerts constantPFC converter is designed, modeled and its torque (i.e. rated torque) on the PMBLDCM andperformance is simulated in Matlab- is operated in speed control mode to improve theSimulink environment for an air efficiency of the Air-Con system.conditioner compressor driven through a 1.5kW, 1500 rpm PMBLDC motor. The Since, the back-emf of the PMBLDCM isevaluation results of the proposed speed proportional to the motor speed and the developedcontrol scheme are presented to torque is proportional to its phase current [1-4],demonstrate an improved efficiency of the therefore, a constant torque is maintained by aproposed drive system with PFC feature in constant current in the stator winding of thewide range of the speed and an input AC PMBLDCM whereas the speed can be controlledvoltage. by varying the terminal voltage of the motor. Based on this logic, a speed control scheme isIndexTerms— PFC, PMBLDCM, Air proposed in this paper which uses a referenceconditioner, Buck Half- bridge converter, Voltage voltage at DC link proportional to the desiredcontrol, VSI. speed of the PMBLDC motor. However, the control of VSI is only for electronic1. Introduction commutation which is based on the rotor PERMANENT magnet brushless dc position signals of the PMBLDC motor.motors (PMBLDCM) are preferred motors for acompressor of an air-conditioning (Air con) system The PMBLDCM drive, fed from a single-due to its features like high efficiency, wide speed phase AC mains through a diode bridge rectifierrange and low maintenance requirements [1-4]. (DBR) followed by a DC link capacitor, suffersThe operation of the compressor with the speed from power quality (PQ) disturbances such ascontrol results in an improved efficiency of the poor power factor (PF), increased total harmonicsystem while maintaining the temperature in the distortion (THD) of current at input AC mains andair-conditioned zone at the set reference its high crest factor (CF). It is mainly due toconsistently. Whereas, the existing air uncontrolled charging of the DC link capacitor 473 | P a g e
  2. 2. Dr. M.Sridhar / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 3, Issue 1, January -February 2013, pp.473-481which results in a pulsed current waveform having sensors for voltage and current signals. Moreover,a peak value higher than the amplitude of the the rotor position signals are used to generatefundamental input current at AC mains. the switching quence for the VSI as anMoreover, the PQ standards for low power electronic commutator of the PMBLDC motor.equipments such as IEC 61000-3-2 [5], Therefore, rotor-position information is requiredemphasize on low harmonic contents and near only at the commutation points, e.g., everyunity power factor current to be drawn from AC 60°electrical in the three- phase [1-4]. The rotormains by these motors. Therefore, use of a power position of PMBLDCM is sensed using Hall effectfactor correction (PFC) topology amongst position sensors and used to generate switchingvarious available topologies [6-14] is almost sequence for the VSI as shown in Table-I.inevitable for a PMBLDCM drive. The DC link voltage is controlled by a Most of the existing systems use a boost half-bridge buck DC-DC converter based on theconverter for PFC as the front-end converter and an duty ratio (D) of the converter. For a fast andisolated DC-DC converter to produce desired effective control with reduced size of magneticsoutput voltage constituting a two-stage PFC drive and filters, a high switching frequency is used;[7-8]. The DC-DC converter used in the second however, the switching frequency (fs) is limitedstage is usually a flyback or forward by the switching device used, operating powerconverter for low power applications and a level and switching losses of the device. Metalfull-bridge converter for higher power oxide field effect transistors (MOSFETs) areapplications. However, these two stage PFC used as the switching device for high switchingconverters have high cost and complexity in frequency in the proposed PFC converter.implementing two separate switch-mode However, insulated gate bipolar transistorsconverters, therefore a single stage converter (IGBTs) are used in VSI bridge feedingcombining the PFC and voltage regulation at DC PMBLDCM, to reduce the switching stress, as itlink is more in demand. The single-stage PFC operates at lower frequency compared to PFCconverters operate with only one controller to switches.regulate the DC link voltage along with the powerfactor correction. The absence of a second The PFC control scheme uses a currentcontroller has a greater impact on the performance control loop inside the speed control loop withof single-stage PFC converters and requires a current multiplier approach which operates indesign to operate over a much wider range of continuous conduction mode (CCM) with averageoperating conditions. current control. The control loop begins with the comparison of sensed DC link voltage with a For the proposed voltage controlled voltage equivalent to the reference speed. Thedrive, a half-bridge buck DC-DC converter is resultant voltage error is passed through aselected because of its high power handling proportional-integral (PI) controller to give thecapacity as compared to the single switch modulating current signal. This signal is multipliedconverters. Moreover, it has switching losses with a unit template of input AC voltage andcomparable to the single switch converters as compared with DC current sensed after the DBR.only one switch is in operation at any instant of The resultant current error is amplified andtime. It can be operated as a single-stage power compared with saw-tooth carrier wave of fixedfactor corrected (PFC) converter when connected frequency (fs) in unipolar scheme (as shown inbetween the VSI and the DBR fed from single- Fig.2) to generate the PWM pulses for the half-phase AC mains, besides controlling the voltage at bridge converter. For the current control of theDC link for the desired speed of the Air-Con PMBLDCM during step change of the referencecompressor. A detailed modeling, design and voltage due to the change in the reference speed,performance evaluation of the proposed drive a voltage gradient less than 800 V/s isare presented for an air conditioner compressor introduced for the change of DC link voltage,driven by a PMBLDC motor of 1.5 kW, 1500 rpm which ensures the stator current of therating. PMBLDCM within the specified limits (i.e. double the rated current).2. PROPOSED SPEED CONTROLSCHEME OF PMBLDC MOTOR FORAIR CONDITIONER The proposed speed control scheme (asshown in Fig. 1) controls reference voltage atDC link as an equivalent reference speed,thereby replaces the conventional control of themotor speed and a stator current involving various 474 | P a g e
  3. 3. Dr. M.Sridhar / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 3, Issue 1, January -February 2013, pp.473-481 buck half-bridge converter. The inductance (Lo) of the ripple filter restricts the inductor peak to peak ripple current (ΔILo) within specified value for the given switching frequency (fs), whereas, the capacitance (Cd) is calculated for a specified ripple in the output voltage (ΔVCd) [7- 8]. The output filter inductor and capacitor are given as, Lo= (0.5-D)Vdc/{fs(ΔILo) } (3) Cd=Io/(2ωΔVCd) (4) The PFC converter is designed for a base DC link voltage of Vdc = 400 V at Vin = 198 V from Vs = 220 Vrms. The turns ratio of the high frequency transformer (N2/N1) is taken as 6:1 to maintain the desired DC link voltage at low input AC voltages typically at 170V. Other design data are fs = 40 kHz, Io = 4 A, ΔVCd= 4 V (1% of Vdc), ΔILo= 0.8 A (20% of Io). The design parametersFigure 1. Control schematic of Proposed Bridge- are calculated as Lo=2.0 mH, Cd=1600 µF.buck PFC converter fed PMBLDCM drive TABLE I. VSI SWITCHING SEQUENCE3. DESIGN OF PFC BUCK HALF- BASED ON THE HALL EFFECT SENSORBRIDGE CONVERTER BASED SIGNALSPMBLDCM DRIVE The proposed PFC buck half-bridge Ha H b Hc Ea Eb Ec S1 S2 S3 S4 S5 S6converter is designed for a PMBLDCM drive 0 0 0 0 0 0 0 0 0 0 0 0with main considerations on PQ constraints at 0 0 1 0 -1 +1 0 0 0 1 1 0AC mains and allowable ripple in DC link 0 1 0 -1 +1 0 0 1 1 0 0 0voltage. The DC link voltage of the PFC converter 0 1 1 -1 0 +1 0 1 0 0 1 0is given as, 1 0 0 +1 0 -1 1 0 0 0 0 1 1 0 1 +1 -1 0 1 0 0 1 0 0Vdc = 2 (N2/N1) Vin D and N2= N21=N22 (1) where 1 1, 1 N N21, 0 22 +1 -1 0 of0turns in 0 0 0 N are number 1 primary, secondary upp 1where N1, N21, N22 are number of turns in 1 1 1 0 0 0 0 0 0 0 0 0primary, secondary upper and lower windings ofthe high frequency (HF) isolation transformer,respectively. 4.MODELING OF THE PROPOSED PMBLDCM DRIVE The main components of the proposed PMBLDCM drive are the PFC converter and PMBLDCM drive, which are modeled by mathematical equations and the complete drive is represented as a combination of these models. A. PFC Converter The modeling of the PFC converter consists of the modeling of a speed controller, a reference current generator and a PWM controllerFigure 2. PWM control of the buck half-bridge as given below.converter 1) Speed Controller: The speed controller,Vin is the average output of the DBR for a given the prime component of this control scheme, is aAC input voltage (Vs) related as, proportional-integral (PI) controller which closely tracks the reference speed as an equivalentVin = 2√2Vs/π reference voltage. If at kth (2) instant of time, A ripple filter is designed to reduce the * (k) is reference DC link voltage, V (k) is V dc dcripples introduced in the output voltage due to sensed DC link voltage then the voltage errorhigh switching frequency for constant of the 475 | P a g e
  4. 4. Dr. M.Sridhar / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 3, Issue 1, January -February 2013, pp.473-481Ve(k) is calculated as, 2) Voltage Source Inverter: Fig. 3 shows anVe(k) =V*dc(k)-Vdc(k) (5) equivalent circuit of a VSI fed PMBLDCM. TheThe PI controller gives desired control output of VSI to be fed to phase „a‟ of thesignal after processing this voltage error. The PMBLDC motor is givenoutput of the controller Ic(k) at kth instant is given vao = (Vdc/2) for S1 = 1 (11)as, vao = (-Vdc/2) for S2 = 1 (12) vao = 0 for S1 = 0, and S2 = 0 (13)Ic (k) = Ic (k-1) + Kp{Ve(k) – Ve(k-1)} +KiVe(k) van = vao – vno (14) (6)where Kp and Ki are the proportional and where vao, vbo, vco, and vno are voltages of theintegral gains of the PI controller. three-phases and neutral point (n) with respect to virtual mid-point of the DC link voltage shown as2) Reference Current Generator: The „o‟ in Fig. 3. The voltages van, vbn, vcn arereference input current of the PFC converter is voltages of three-phases with respect to neutraldenoted by idc* and given as, point (n) and Vdc is the DC link voltage. S= 1i*dc = Ic (k) uVs (7) and 0 represent „on‟ and „off‟ position of respective IGBTs of the VSI andwhere uVs is the unit template of the voltage considered in a similar way for other IGBTs of theat input AC VSI i.e. S3- S6.mains, calculated as,uVs=vd/Vsm;vd = |vs|; vs= Vsm sin ωt (8) Using similar logic vbo, vco, vbn, vcn are generated for other two phases of the VSI feedingwhere Vsm is the amplitude of the voltage and ω PMBLDC frequency in rad/sec at AC mains. 3) PMBLDC Motor:The PMBLDCM is3) PWM Controller:The reference input represented in the form of a set of differentialcurrent of the buck half-bridge converter (idc*) is equations [3] given as,compared with its sensed current (idc) to generate van = Ria + pλa +ean (15)the current error Δidc=(idc* - idc). This current vbn = Rib + pλb +ebn (16)error is amplified by gain kdc and compared with vcn = Ric + pλc +ecn (17)fixed frequency (fs) saw-tooth carrier waveform where p is a differential operator (d/dt), ia, ib, icmd(t) (as shown in Fig.2) in unipolar switching are three-phasemode [7] to get the switching signals for theMOSFETs of the PFC buck half-bridgeconverter as,If kdc Δidc > md (t) then SA = 1else SA = 0 (9)If -kdc Δidc > md (t)then SB = 1 else SB = 0 (10) where SA, SBare upper and lower switches of the half-bridgeconverter as shown in Fig. 1 and their values Figure 3.Equivalent Circuit of a VSI fed„1‟ and „0‟ represent „on‟ and „off‟ position of the PMBLDCM Driverespective MOSFET of the PFC converter. The flux linkages are represented as, λa = Lia - M (ib + ic) (18)B. PMBLDCM Drive λb = Lib - M (ia + ic) (19)The PMBLDCM drive consists of anelectronic commutator, a VSI and a PMBLDC λc = Lic - M (ib + ia) (20)motor. where L is self-inductance/phase, M is mutual inductance of motor winding/phase. Since the1) Electronic Commutator: The electronic PMBLDCM has no neutral connection, therefore,commutator uses signals from Hall effect position ia + ib + ic = 0 (21)sensors to generate the switching sequence for the From Eqs. (14-21) the voltage between neutralvoltage source inverter based on the logic given terminal (n) and mid-point of the DC link (o) isin Table I. given as, vno={vao+vbo+vco–(ean+ebn+ecn)}/3 (22) From Eqs. (18-21), the flux linkages are given as, 476 | P a g e
  5. 5. Dr. M.Sridhar / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 3, Issue 1, January -February 2013, pp.473-481λa = (L+M) ia, λb = (L+M) ib, DC link voltage. The detailed data of the motor λc = (L+M) ic, (23) and simulation parameters are given in Appendix. The performance of the proposedFrom Eqs. (15-17 and 23), the current PFC drive is evaluated on the basis ofderivatives in generalized state space form is given various parameters such as total harmonicas, distortion (THDi) and the crest factor (CF) of the current at input AC mains, displacementpix = (vxn - ix R – exn)/(L+M) (24) power factor (DPF), power factor (PF) andwhere x represents phase a, b or c. efficiency of the drive system (ηdrive) at different speeds of the motor. Moreover, these parametersThe developed electromagnetic torque,Te are also evaluated for variable input AC voltagein the PMBLDCM is given as, at DC link voltage of 416 V which is equivalent to the rated speed (1500 rpm) of theTe = (ean ia + ebn ib +ecn ic)/ ω (25) PMBLDCM. The results are shown in Figs. 4-9where ω is motor speed in rad/sec, and Tables II- III to demonstrate the effectiveness of the proposed PMBLDCMThe back emfs may be expressed as a function drive in a wide range of speed and input ACof rotor position (θ) as, voltage.exn= Kb fx(θ) ω A. Performance during Starting The performance of the proposed(26) where x can be phase a, b or c and accordingly PMBLDCM drive fed from 220 V AC mainsfx(θ) represents function of rotor position with a during starting at rated torque and 900 rpm speedmaximum value ±1, identical to trapezoidal is shown in Fig. 4a. A rate limiter of 800 V/s isinduced emf given as, introduced in the reference voltage to limit thefa(θ) = 1 starting current of the motor as well as the for 0 < θ < 2π/3 (27) charging current of the DC link capacitor. The PI fa(θ) = {(6/ π)( π- θ)}-1 controller closely tracks the reference speed so thatfor 2π/3 < θ < π (28) the motor attains reference speed smoothly within fa(θ) = -1 for π < θ < 5π/3 (29) 0.35 sec while keeping the stator current withinfa(θ) = {(6/π)(θ -2π)}+1 for 5π/3 < θ < 2π (30)the desired limits (θ) and fc(θ) are similar to The with a The functions fb i.e. double the rated value. fa(θ)phase difference of 120º and 240º respectively. current (is) waveform at input AC mains is inTherefore, the electromagnetic torque is expressed phase with the supply voltage (vs)as, demonstrating nearly unity power factor during theTe = Kb{fa(θ) ia + fb(θ) ib+ fc(θ) ic} (31) starting.The mechanical equation of motion in speedderivative form is given as, B. Performance under Speed Control Figs. 4-6 show the performance of thepω = (P/2) (Te-T L-Bω)/(J) (32) proposed PMBLDCM drive under the speedThe derivative of the rotor position angle is given controlas, pθ = ω (33) whereP is no. poles, T L is load torque in Nm, J ismoment of inertia in kg-m2 and B is frictioncoefficient in Nms/Rad.These equations (15-33) represent the dynamicmodel of the PMBLDC motor.5.PERFORMANCE EVALUATION OFPROPOSED PFC DRIVE The proposed PMBLDCM drive ismodeled in Matlab- Simulink environment andevaluated for an air conditioning compressorload. The compressor load is considered as aconstant torque load equal to rated torque withthe speed control required by air conditioningsystem. A 1.5 kW rating PMBLDCM is used todrive the air conditioner compressor, speed ofwhich is controlled effectively by controlling the 477 | P a g e
  6. 6. Dr. M.Sridhar / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 3, Issue 1, January -February 2013, pp.473-481 478 | P a g e
  7. 7. Dr. M.Sridhar / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 3, Issue 1, January -February 2013, pp.473-481 479 | P a g e
  8. 8. Dr. M.Sridhar / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 3, Issue 1, January -February 2013, pp.473-481at constant rated torque (9.55 Nm) and 220 V ACmains supply voltage. These results arecategorized as performance during transient andsteady state conditions.1) Transient Condition: Figs. 4b-c show theperformance of the drive during the speed controlof the compressor. The reference speed is changedfrom 900 rpm to 1500 rpm for the rated load Fig. 6a. DC link voltage with speed Fig.6b.performance of the compressor; from 900 rpm Efficiency with loadto Figure 6. Performance of the proposed PFC300 rpm for performance of the compressor at drive under speed control at rated torque and 220light load. It is observed that the speed control is VACfast and smooth in either direction i.e.acceleration or retardation with power factormaintained at nearly unity value. Moreover, thestator current of PMBLDCM is within theallowed limit (twice the rated current) due tothe introduction of a rate limiter in thereference voltage.2) Steady State Condition:The speedcontrol of the PMBLDCM driven compressorunder steady state condition is carried out fordifferent speeds and the results are shown in Figs. Fig. 7a. THD of current at AC mains Fig. 7b. DPF5-6 and Table-II to demonstrate the effectiveness and PFof the proposed drive in wide speed range. Figure 7. PQ parameters of PMBLDCM driveFigs.5a-c show voltage (vs) and current (is) under speed control at rated torque and 220 VACwaveforms at AC mains, DC link voltage (Vdc), inputspeed of the motor (N), developedelectromagnetic torque of the motor (T e), thestator current of the PMBLDC motor for phase„a‟ (Ia), and shaft power output (Po) at 300rpm, 900 rpm and 1500 rpm speeds. Fig. 6ashows linear relation between motor speed andDC link voltage. Since the reference speed isdecided by the reference voltage at DC link, itis observed that the control of the reference DClink voltage controls the speed of the motorinstantaneously. Fig. Figure 8. Current waveform at AC mains and its6b shows the improved efficiency of the drive harmonic spectra of the PMBLDCM drive undersystem (ηdrive) steady state condition at rated torque and 220 VACin wide range of the motor speed.C. Power Quality Performance TABLE III. VARIATION OF PQThe performance of the proposed PMBLDCM PARAMETERS WITH INPUT AC VOLTAGEdrive in terms of various PQ parameters such as (VS) AT 1500 RPM (416 VDC)THDi, CF, DPF, PF is summarized in Table-IIand shown in Figs. 7-8. Nearly unity power factor VAC THDi DPF PF CF Is ηdrive(PF) and reduced THD of AC mains current are (V) (%) (A) (%)observed in wide speed range of the PMBLDCM 170 2.88 0.9999 0.9995 1.41 10.4 84.9as shown in Figs. 7a-b. The THD of AC mains 180 2.59 0.9999 0.9996 1.41 9.7 85.8current remains less than 5% along with nearly 190 2.40 0.9999 0.9996 1.41 9.2 86.3unity PF in wide range of speed as well as load asshown in Table-II and Figs. 8a-c. 200 2.26 0.9999 0.9996 1.41 8.6 87.2 210 2.14 0.9999 0.9997 1.41 8.2 87.6 220 2.09 0.9999 0.9997 1.41 7.7 88.1 230 2.07 0.9999 0.9997 1.41 7.4 88.2 240 2.02 1.0000 0.9998 1.41 7.1 88.4 250 1.99 1.0000 0.9998 1.41 6.8 88.7 260 2.01 1.0000 0.9998 1.41 6.5 88.7 270 2.01 1.0000 0.9998 1.41 6.2 89.0 480 | P a g e
  9. 9. Dr. M.Sridhar / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 Vol. 3, Issue 1, January -February 2013, pp.473-4816.CONCLUSION IEEE Trans. Industrial Electron., vol. 50, A new speed control strategy of a no. 5, pp. 962 – 981, oct. 2003.PMBLDCM drive is validated for a compressor [7] N. Mohan, T. M. Undeland and W. P.load of an air conditioner which uses the Robbins, “Power Electronics:reference speed as an equivalent reference voltage Converters, Applications and Design,”at DC link. The speed control is directly John Wiley, USA, 1995.proportional to the voltage control at DC link. [8] A. I. Pressman, Switching PowerThe rate limiter introduced in the reference Supply Design, McGraw Hill, New Yorvoltage at DC link effectively limits the k, 1998.motor current within the desired value during the [9] P.J. Wolfs, “A current-sourced DC-DCtransient condition (starting and speed control). converter derived via the dualityThe additional PFC feature to the proposed drive principle from the half-bridgeensures nearly unity PF in wide range of speed converter,” IEEE Trans. Ind. Electron.,and input AC voltage. Moreover, power quality vol. 40, no. 1, pp. 139 – 144, Feb. 1993.parameters of the proposed PMBLDCM drive are [10] J.Y. Lee, G.W. Moon and M.J. Youn,in conformity to an International standard IEC “Design of a power-factor- correction61000-3-2 [5]. The proposed drive has converter based on half-bridgedemonstrated good speed control with energy topology,” IEEE Trans. Ind. Electron.,efficient operation of the drive system in the vol. 46, no. 4, pp.710 – 723, Aug 1999.wide range of speed and input AC voltage. The [11] J. Sebastian, A. Fernandez, P.J.proposed drive has been found as a promising Villegas, M.M. Hernando and J.M.candidate for a PMBLDCM driving Air-Con Lopera, “Improved active input currentload in 1-2 kW power range. shapers for converters with symmetrically driven transformer,” IEEEAPPENDIX Trans. Ind. Appl., vol. 37, no. 2, pp. 592 Rated Power: 1.5 kW, rated speed: – 600, March-April 2001.1500 rpm, rated current: 4.0 A, rated torque: [12] A. Fernandez, J. Sebastian, M.M.9.55 Nm, number of poles: 4, stator resistance Hernando and P. Villegas, “Small(R): 2.8 Ω/ph., inductance (L+M): signal modelling of a half bridge5.21mH/ph., back EMF constant (Kb): 0.615 converter with an active input current shaper,” in Proc. IEEE PESC, 2002,Vsec/rad, inertia (J): 0.013 Kg- m2. Source vol.1, pp.159 – 164.impedance (Zs): 0.03 pu, switching frequency [13] S.K. Han, H.K. Yoon, G.W. Moon,of PFC switch (fs) = 40 kHz, capacitors (C1= M.J. Youn, Y.H. Kim and K.H. Lee,C2): 15nF, PI speed controller gains (Kp): 0.145, “A new active clamping zero-voltage(Ki): 1.45. switching PWM current-fed half-bridge converter,” IEEE Trans. Power Electron., vol. 20, no. 6, pp. 1271 – 1279, Nov.REFERENCES 2005. [1] T. Kenjo and S. Nagamori, Permanent [14] R.T.Bascope, L.D.Bezerra, Magnet Brushless DC Motors, G.V.T.Bascope, D.S. Oliveira, Clarendon Press, oxford, 1985. C.G.C. Branco, and L.H.C. Barreto, [2] T. J. Sokira and W. Jaffe, “High frequency isolation on-line UPS Brushless DC Motors: Electronic system for low power applications,” in Commutation and Control, Tab Books Proc. IEEE APEC’08, 2008, pp.1296 – USA, 1989. 1302. [3] J. R. Hendershort and T. J. E. Miller, Design of Brushless Permanent- Magnet Motors, Clarendon Press, Oxford, 1994. [4] J. F. Gieras and M. Wing, Permanent Magnet Motor Technology – Design and Application, Marcel Dekker Inc., New York, 2002. [5] Limits for Harmonic Current Emissions (Equipment input current ≤16 A per phase), International Standard IEC 61000-3-2, 2000. [6] B. Singh, B. N. Singh, A. Chandra, K. Al-Haddad, A. Pandey and D. P. Kothari, “A review of single-phase improved power quality AC-DC converters,” 481 | P a g e