1 A Power-Frequency Controller With Resonance Frequency Tracking .
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.2017.2779425, IEEETransactions on Industry Applications1A Power-Frequency Controller withResonance Frequency Tracking Capabilityfor Inductive Power Transfer SystemsMasood Moghaddami, Student Member, IEEE, Aditya Sundararajan, Student Member, IEEEand Arif I. Sarwat, Senior Member, IEEEAbstract—A self-tuning controller for power transfer regulation in inductive power transfer (IPT) systems is proposed in thispaper. The controller enables power transfer regulation arounda user-defined reference power level. The converter’s efficiencyis improved by constantly tuning the switching operations to theresonant current, thereby achieving the soft-switching operationsreducing the electromagnetic interference (EMI) the power converters. The self-tuning capability makes it ideal for dynamicIPT systems with uncertain loads and fluctuating resonancefrequency. High operating frequencies can be achieved using thesimplified digital circuit design for the controller, proposed in thispaper, which delivers a low total propagation delay. Bidirectionalpower transfer can be enabled by using the proposed controlleron both transmitter as well as receiver sides. In the reverse powerflow mode, the primary converter operates as a rectifier and thepower transfer is controlled through the secondary converterusing the proposed controller. The performance of the proposedcontroller is analyzed using MATLAB/Simulink, and the resultsare presented. Finally, the proposed controller is implementedexperimentally and its performance is evaluated as a case studyon an IPT system. The experimental and simulation resultsconform to each other and show that the proposed convertercan effectively regulate the power transfer with an improvedefficiency.Index Terms—inductive power transfer, power control, selftuning control, soft-switching.I. I NTRODUCTIONINDUCTIVE Power Transfer (IPT) systems based on theresonant magnetic induction constitute a new technology which enables power transmission between two systemswithout physical contacts. Owing to its superior robustness,reliability and safety in comparison with the existing methods,they are applied widely as bio-medical implants [1], materialhandling [2], transportation systems [3]. Over the recent years,the IPT-based charging systems for contactless Electric Vehicles (EVs) has been on the rise, broadly categorized as static[4], [5], and dynamic or in-motion charging modes [6], [7].Presenting themselves as a formidable alternative to thetraditional wired charging in EV charging stations, static EVcharging systems provide more safety and convenience to theusers of EVs. At the same time, a growing interest has emergedin the dynamic EV charging systems, and it is now regardedThe authors are with the Department of Electrical and ComputerEngineering, Florida International University, Miami, FL, 33174 t@fiu.edu)This work was supported by the National Science Foundation under grantnumber ensationControllerFig. 1. Typical structure of an inductive power transfer system.as one of the technological cornerstones that can revolutionize the world of transportation systems. The contactless EVcharging systems are equipped with bidirectional power flowcapabilities to enable Grid-to-Vehicle (G2V) and Vehicle-toGrid (V2G) connections [8]. Improving the resiliency of thefuture infrastructure of smart grid is touted to be one of themajor benefits of V2G connections, since they can afford tosupport the grid under extreme conditions, or through peakshaving [9], [10]. The structure of a typical IPT system isillustrated in Fig. 1.Power flow control plays a crucial role in the IPT system’s optimal operation, which can in turn be attained bycontrolling the transferred power to either the transmitter or thereceiver, or both [11]. In the literature, several techniques forpower flow control for IPT systems exist, including resonancefrequency control [12], power-frequency control [13]–[15],phase-shift control [16]–[18], load detection [19], reactivepower control [11], and sliding mode control (SMC) [20],[21]. Tuning the control parameters and handling the systemvariability can be made possible by modifying the controlmethods to be adaptive with self-tuning capability [22], [23].The self-tuning capability of such controllers can significantlyenhance the performance and interoperability of IPT systems.Soft-switching operations in power converters can significantly improve the efficiency and reduce their electromagneticfield emission (EMI) [24]. Since IPT systems for electricvehicle applications usually operate at frequencies rangingbetween 20 and 85 kHz, the performance of the powerconverters, considerably affect their performance. Thus, byensuring soft-switching operations of the converter, the con-0093-9994 (c) 2017 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.2017.2779425, IEEETransactions on Industry Applications2TABLE ID ISTINCT POWER TRANSFER LEVELS AND CORRESPONDING ENERGYINJECTION FREQUENCIES FOR POSITIVE AND NEGATIVE HALF - CYCLES .S3S1 CS2ReqS4Three-phaseConverterS1S2Ssgnm 1m 2S3m 4DCACm 8S4!Q Clk !Q Clk !Q Clk QQQDir1-11-21-41-82-22-42-84-44-88-8L 3 inputPower Leveln-mFrequency of energy injectionPositiveNegativehalf-cycleshalf-cycles(fr /n)(fr /m)frfrfrfr /2frfr /4frfr /8fr /2fr /2fr /2fr /4fr /2fr /8fr /4fr /4fr /4fr /8fr /8fr /8DD10-levelADCGNDreversePrefn 8trollers can greatly improve the performance of the system.One method capable of effective power flow control in IPTsystems is the energy-injection free-oscillation. This technique,which enables soft-switching operations, has been successfullyapplied in many studies [22], [25]–[27].Conventionally, Pulse Width Modulation (PWM) basedpower electronic converters are used in IPT systems anddesired outputs are achieved by controlling the frequency andduty-cycle of the PWM signal [28], [29]. In [22], [30], a control method based on a variable frequency control technique isproposed for inductive EV charging systems, which is utilizedin this paper. This method achieves multiple power transferlevels in a full-bridge DC/AC converter, and is designed toreduce the frequency of energy injection (rather than changing the duty-cycle of a PWM signal) without compromisingthe resonance behavior of the IPT system. The developedcontroller is open-loop and provides multiple power transferlevels. It is noteworthy that the terms “energy injection level”and “power transfer level” mean the same and are hence usedinterchangeably throughout this paper.The main contribution of this paper is the proposition,design and implementation of a power-frequency controllerthat regulates the power transfer rate in accordance with thedesired level (specified by the user) and tracks the resonancefrequency of the system in a way that maximizes the powertransfer efficiency. This controller also ensures its performanceis not affected by system changes due to dynamic variations,as is the case in roadway IPT systems. Above all, the methodproposed in this paper simplifies the design and complexityof the controller, thereby reducing implementation costs. Theexisting methods in literature fall short in all of the aboveaspects, highlighting the uniqueness of the proposed controller.Although the proposed controller leverages similar benefits interms of its self-tuning capability, low EMI, soft-switchingoperations, low switching stress, etc., its real novelty lies in thesimplified, cost-effective design, and its ability to maximizepower transfer efficiency even in dynamic system environments. A digital circuit-based design and implementation ofthe proposed controller is presented, which is capable ofeffectively regulating the transferred power. In order to validatethe controller’s efficacy, it is analyzed theoretically, simulatedin MATLAB/Simulink, and then experimentally implemented,the results of which are discussed in detail.Encodern 4n 2n 1abcdFig. 2. The proposed power-frequency controller designed based on a digitalcontrol circuit.II. P ROPOSED C ONTROL M ETHODA control method based on variable frequency energyinjection and free-oscillation technique for IPT systems ispresented in [22], which provides 10 power transfer levels(TABLE I). These power levels are achieved by independentlycontrolling the frequency of energy-injection into the IPTsystem at positive and negative half-cycles of the resonantcurrent. The power transfer levels are labeled as n-m, wheren and m correspond to fr /n and fr /m energy-injectionfrequencies for positive and negative half-cycles, respectively(where fr is the resonance frequency). Figure 3 conceptuallyshows the positive and negative half-cycle energy-injectionsignals for different power levels (n, m {1, 2, 4, 8}). Inthis study, the control technique is further developed in orderto design a closed-loop self-tuning controller that enablespower transfer regulation in IPT systems. This is achieved bydesigning a control loop for power level that can regulate thepower level around the reference power (Pref ) by switchingbetween energy-injection states presented in TABLE I.A. Power-Frequency ControllerThe proposed controller along with a full-bridge DC/ACconverter connected to an RLC is shown in Fig. 2. The RLCload represents the IPT system where L is the self-inductanceof the primary coil, C is the series compensation capacitor,and Req is the equivalent reflected resistance of the secondary.The controller takes the resonant current as feedback generatesfour output signals to control the full-bridge converter basedon the reference power level (Pref ). The proposed controlleris comprised of a differential comparator, AND, OR, NOTlogic gates, flip-flops, signal rectifier, 10-level analog to digitalconverter (ADC) and an encoder.Figure 3 conceptually shows the positive and negativehalf-cycle energy-injection signals for different power levels(n, m {1, 2, 4, 8}) which are presented in TABLE I and0093-9994 (c) 2017 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.2017.2779425, IEEETransactions on Industry ApplicationsB. Self-Tuning CapabilityThe power electronic converters used in IPT systems shouldoperate at the resonance frequency of the system in order toachieve the maximum power transfer efficiency. Any deviation from the resonance frequency can dramatically affectthe performance of the system. Due to different operatingconditions in IPT systems such as, transmitter and receiveralignment, load characteristics, etc., the characteristics of thesystem including resonance frequency may change. Also,different IPT systems can be designed based on a range ofoperating resonance frequencies (e.g. 20-85 kHz for inductiveEV charging systems). Furthermore, IPT systems can havea variable resonance frequency for different purposes [31].Therefore, the use of self-tuning controllers that can trackand tune the switching operations of the converters with theresonance frequency of the IPT system would be of greatinterest, as it eliminates the need for manual tuning and itcan significantly enhance the performance of the system.n 1n 2n 4n 8m 1m 2m 4m 8the control circuit diagram shown in Fig. 2. These energyinjection signals are generated using a three-stage frequencydivider (three flip-flops connected in series) and are routedto the output switching signals using two 4-input multiplexercircuits (combination of 2 NOT gates, 4 AND gates, and anOR gate). The multiplexers are switched using four selectors(a and b for negative half-cycles, and c and d for positive halfcycles) which are determined based on the resonant currentamplitude and the reference power (Pref ).The circuit is designed to achieve zero-current switchingby synchronizing the switching operations with the resonantcurrent. This is done using the output of the resonant currentzero-cross detector (output of the differential comparator,Ssgn ) as a clock source signal for the resonance frequencydivider. The frequency divider is used to change the energyinjection frequency in order to control the power transferlevel. A signal rectifier (AC/DC converter) is used to convertthe measured AC resonant current into a DC signal in orderto enable comparisons with the reference level. This signaldetermines the level of the resonant current. Using an ADC,the corresponding DC signal is then converted to a 4-digitsignal by comparing the equivalent DC signal to the referencelevel input. Based on the level of the resonant current, theencoder generates 4 signals to control the power transfer leveland minimize the power level error respect to the referencepower level. The power transfer control is achieved by tuningthe frequency of energy injection to the IPT systems usingtwo multiplexer circuits for positive and negative half-cycleenergy injection signals, which are generated by the resonancefrequency divider circuits (series connected flip-flops andcorresponding logic gates).The “reverse” input is used to enable reverse power flowmode by disabling all the switching signals and thus allowingthe converter to operate as a rectifier. In this case, the secondary coil works as a transmitter and the primary coil worksas a receiver allowing a reverse power flow. If the primarycircuit is powered by an AC source, an inverter is requiredbetween the AC power source and the DC-link in order toenable power transfer to the grid, forming a V2G connection.ResonantCurrent3Fig. 3. Resonant current and corresponding positive and negative half-cycleenergy injection signals for n, m {1, 2, 4, 8}.The proposed controller (Fig. 2) synchronizes the switchingsignals with the resonant current of the IPT system to enablethe self-tuning capability. This is achieved by using the resonant current sign signal (Ssgn determined by the differentialcomparator), and its complement Ssgn as clock sources forthe entire control circuit. This ensures that the switchingoperations always occur at the resonant current zero-crossingpoints, and therefore, the converter is switched at the resonancefrequency. This also enables zero-current switching operationswhich significantly enhance the performance of the converterand reduce switching stress.III. T HEORETICAL A NALYSISThe proposed power controller achieves power transfer control based on resonant current regulation. Therefore, finding ananalytical solution for the resonant current in an IPT systemwould be useful in order to calculate the power transfer levelat different energy injection frequencies.A. Power Transfer LevelIn an RLC circuit shown in Fig. 2, the equation for theresonant current can be written as follows:Zdi1nmL idt Req i Vinj (t) Vinj (t)(1)dt Cnmwhere i is the resonant current, Vinj (t) and Vinj (t) areoutput voltage pulses of the converter at energy injection leveln-m in positive and negative half-cycles respectively. In Fig.nm4, Vinj (t) and Vinj (t) for power level 2-4 (n 2 and m 4)are conceptually shown. These input functions are periodicwith cycles of 2nπ/ω and 2mπ/ω (ω is the frequency of theresonant current), and can be expressed as follows:(Vt 0 t ωπn(2)Vinj (t) π2nπ0ω t ωmVinj (t)( Vt 0πω t 2πω0 t ωπ ,2πω t 2mπω(3)0093-9994 (c) 2017 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.2017.2779425, IEEETransactions on Industry Applications4Fig. 4. The resonant current and corresponding switching signals controlled using the proposed controller for power level 2-4 (n 2, m 4).Equation (1) can be solved by applying the superpositionnmlaw and considering Vinj (t) and Vinj (t) as two separateinput functions:1di1 dtCZLdi21 dtCZLni1 dt Req i1 Vinj (t)(4)mi2 dt Req i2 Vinj (t)(5)nwhere i1 and i2 are corresponding solutions due to Vinj (t)mand Vinj (t) input functions respectively. First, the analyticalnsolution for i1 is found. Since in each half-cycle Vinj (t) isconstant, (4) can be rewritten as follows:d2 i1Req di11 i1 0.2dtL dtLC(6) πwhere β e τ ω . Using (2), (8), and (9), i1 can be derived asfollows: 1 β 2n 1 Vt e t/τ sin(ωt) 0 t ωπ ωL(1 β 2n )i1 (t) 2n 1 (1 β)β Vt e t/τ sin(ωt) ωπ t 2nπωωL(1 β 2n )(10)Since negative half-cycle energy injection always happensafter a positive half-cycle energy injection, the following canbe obtained:mmVinj (t) Vinj (t i1 (0) 0,(7)nwhere Vinj (t) is the converter output voltage and vc (0) is theinitial capacitor voltage. Therefore, the solution of (6) wouldbe as follows:i1 nVinj vc (0) t/τesin(ωt).ωL(8)pwhere ω ω02 1/τ 2 is the natural resonance frequency,ω0 1/ LC is the resonance frequency, and τ 2L/Reqis the damping time constant. Assuming that the system hasreached to a steady-state condition, vc (0) can be calculated asfollows [22]:vc (0) (1 β) 2n 1βVt1 β 2n(9)(11)Since (4) is linear and time-invariant, based on (11) thefollowing is obtained:The controller is designed in way that zero-current switching is obtained. Therefore, the initial conditions would be asfollows:di1nL(0) Vinj (t) vc (0)dtπ)ωi2 (t) i1 (t π)ω(12)n mIn order to eliminate the power levels that will result in arepetitive power level, the proposed controller is designed ina way that n m. Using (12) and (10), i2 can be written asfollows:i2 (t) (1 β)β 2m 2 Vt e t/τ sin(ωt) ωL(1 β 2m )0 t 1 β 2m 1 Vt e t/τ sin(ωt)ωL(1 β 2m )βπωπω(13) t 2mπωApplying the superposition principle for differential equations, the final solution for the resonant current can be expressed as follows:i i1 i2(14)0093-9994 (c) 2017 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.2017.2779425, IEEETransactions on Industry Applications5Using the analytical solution for the resonant current, thetransferred power can be obtained as follows:Pinj 02mπω mn(t) i(t) dt(t) Vinj Vinj 2mπ/ω2(i 1)π/ωPinj Output powerSteady-state error0.8(15)Considering the fact that in a full cycle (0 t 2mπ/ω)there would be m/n positive half-cycle energy-injections andonly one negative half-cycle energy-injection, (15) can berewritten as follows:m/nR (2i 1)π/ωX10.6Power (P.U.)R0.40.20-0.2Vdc i(t)dt R 2π/ωπ/ω Vdc i(t)dt00.10.20.30.40.50.6Reference Power (P.U.)0.70.80.91i 12mπ/ω(16)Using (10) and (13), (16) the power transfer level can becalculated based on IPT system parameters L, C, Req , DC-linkvoltage Vdc , and power transfer level n-m. This equation isspecifically useful for estimating the output power at differentpower transfer levels given in TABLE I.Fig. 5. The output power and steady-state error as a function of referencepower.injection level (no power level regulation), the RMS outputvoltage of the converter is constant, therefore there would bean inverse relationship between power level and Req .B. Voltage Gain of the ConverterC. System Response TimeSince the proposed controller tunes the output voltage ofthe converter by switching to different modes of operation, itsvoltage gain characteristic would be of great interest. The RMSoutput voltage at power transfer level n-m can be calculatedas follows:vRu 2mπ/ωuVt2 dtt 0Vrms (17)2mπ/ωSince an IPT system can be represented with an equivalentRLC circuit (shown in Fig. 2), the settling time of the systemwithin 2% of the final value can be expressed as follows:Based on Fig. 4, (17) can be rewritten as,vu m/nu XRR 2π/ω(2i 1)π/ωu2 dt2 dt uVdcVdcπ/ω2(i 1)π/ωut i 1Vrms 2mπ/ωEquation (18) can be simplified as follows:sr2 π/ω(m/n 1) Vdcn mVrms Vdc2mπ/ω2nmTs ' 4τ 8LReq(21)Equation (1) shows that there is an inverse relationship between response time of the system and Req . The relationshipbetween power level and different system parameters includingReq is presented in (16).D. Steady-State Error(18)(19)Using (19) the voltage gain of the converter can be obtainedas follows:rVrmsn mGv (20)Vdc2nmAccording to (20), the converter using the proposed controller operates as a controlled voltage source for the primarywith control parameters n and m. In IPT systems (specifically dynamic IPT systems), Req can change due to inherentvariations of the system such as vehicle alignment relative toprimary and number of charging vehicles. The controller isdesigned to regulate the voltage gain with the variations ofReq to achieve the desired power transfer level (Pref ). Forinstance, if Req decreases, output voltage of the converteris reduced (n and/or m are increased) to regulate the powerlevel around Pref . In other words, lower Req results in lowerenergy-injection levels (higher n and/or m). At a fixed energyAs discussed in Section II, the proposed controller operates based on 10 discrete power transfer levels presented inTABLE I. This means that the controller switches betweenthese discrete power levels to minimize the output powererror. In Fig. 5, the output power and steady-state error areplotted as a function of reference power. The output power(P.U.) is calculated using (16) at different energy injectionlevels and the relationship between the output power and thereference power (P.U.) is determined based on the design ofthe controller. Figure 5 shows that the maximum steady-stateerror of the system is 22%.IV. S IMULATION R ESULTSThe proposed controller along with an IPT system is modeled and simulated in MATLAB/Simulink using SimPowerSystem toolbox and the performance of power transfer regulation is evaluated at different conditions. The simulation modeland the specifications of the IPT system are presented in Fig.6 and TABLE II respectively. The IPT system is comprisedof a three-phase two-stage AC/DC/AC converter connectedto the primary circuit, magnetic couplers, compensation capacitors, secondary AC/DC converter which charges an EV0093-9994 (c) 2017 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.2017.2779425, IEEETransactions on Industry Applications6TABLE IIID ISTINCT POWER TRANSFER LEVELS AND CORRESPONDING ENERGYINJECTION FREQUENCIES FOR POSITIVE AND NEGATIVE HALF - CYCLES .8044.3836.9428.16Batterychargingcurrent 95Batterychargingpower ABLE IVS PECIFICATIONS OF THE EXPERIMENTAL IPTFig. 6. The case study IPT system simulation model.Power (kW)ParameterPrimary and secondary self-inductancesPrimary and secondary compensation capacitorsResonance frequencyGrid line voltageEV battery voltageEV battery capacitySYSTEM .Value172 µH120 nF35 kHz208 V360 V22 Power Level2-84-44-88-8Efficiency (%)TABLE IIS PECIFICATIONS OF THE CASE STUDY IPTParameterPad self-inductanceCompensation capacitorsPrimary supplySecondary battery86Fig. 7. Power and efficiency of the converter at different power transfer levelscalculated based on simulation results.battery. The power controller is modeled based on the controlcircuit presented in Fig. 2 using AND, OR and NOT logicgates, flip-flops, ADC conversion. The voltage comparator ismodeled as a “compare to zero” block which acts as zero-crossdetector. The current measurement transformer is modeled asa controlled current source with a 1:1000 conversion ratio.The current measurement signal is converted into a DC signalusing a half-wave rectifier which is then connected to theADC/Encoder block in order to switch the controller to theappropriate power transfer level. The controller generates theswitching signals of the second stage (inverter stage) of theprimary converter. The reference power level is determinedusing (16), based on the energy injection levels for positiveand negative half-cycles (n and m).The simulations are carried out for all power levels according to TABLE I, and the results are presented in TABLEIII. The results include grid power and current (rms), batterycharging power and current, and efficiency of the system. Also,Components15 turns, 10 AWG Litz wireFilm capacitor, FPG66Y0124JVariable three-phase AC supplyLead-acid 94.0892.8791.0187.75SYSTEM .Value172 µH120 nF10 V (LL), 60 Hz12 V, 86.4 Whthe power level and efficiency of the system at different powerlevels are presented in Fig. 7 which shows that as the powerlevel drops (higher n and/or m), the efficiency of the converterdrops. It is due to the fact that at lower power levels, thenumber of free-oscillation cycles by the controller, in order toreduce energy injection into the IPT system, thereby allowingthe resonant current to freely oscillate through the switchesof the converter. This in turn increases conduction losses inthe converter. Figure 7 also shows that for the first five powerlevels (levels 1-1, 1-2, 1-4, 2-2, 2-4), the converter can achievea minimum efficiency of 96%. Furthermore, the maximumefficiency that is achieved at level 1-1 with 33.83 kW poweris 98.54%.By applying step changes in the reference power level,the performance of the controller is analyzed in trackingthe reference power level. In Fig. 8, the simulation resultsincluding resonant current, DC-link current, energy-injectionswitching signals, reference power and output power arepresented for different power level transitions. The outputpower is calculated based on the power delivered to batteriesat the secondary circuit. Figure 8(a) shows the transition fromlevel 1-4 (18 kW) to level 2-2 (12 kW). In Fig. 8(b) transitionfrom level 2-4 (10 kW) to level 1-2 (20 kW). Also, in Fig.8(c) transition from level 1-4 (18 kW), level 2-2 (12 kW), level2-4 (10 kW) and level 1-2 (20 kW) are presented. The resultsshow that the using the proposed controller, the output powerof the IPT system effectively tracks the reference current(estimated output power) with low discrepancy. The controllereffectively changes the energy injection frequencies in orderto conform to the reference power level. In Figs. 8(a) and (b),itcan be seen that the switching operations always occur at theresonant current zero-crossing points which verifies the selftuning capability of the controller and zero-current switching(ZCS) in the converter described earlier in Section II-B.0093-9994 (c) 2017 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.2017.2779425, IEEETransactions on Industry ApplicationsResonantCurrent (A)1000-1008.68.899.25008.48.68.899.2OutputVoltage (V)8.22000-2008.28.48.68.899.20.5ReferencePower (kW)OutputPower 625.824.624.82525.225.425.625.824.624.82525.2Time (ms)25.425.625.808102510.502024.82000-200S3, S4S3, S48124.6150100500DC-linkCurrent (A)8.41008OutputVoltage (V)8.20ReferencePower (kW)DC-linkCurrent (A)8100-100OutputPower (kW)ResonantCurrent (A)788.28.48.6Time (ms)8.899.2(a)(b)ReferencePower (kW)201510505101520253051015Time (ms)202530OutputPower (kW)20151050(c)Fig. 8. Simulation results on the case study IPT system showing resonant current, DC-link current, energy-injection switching signals (S3 , S4 ), referencepower and output power: (a) Transition from Level 1-4 (18 kW) to Level 2-2 (12 kW), (b) Transition from Level 2-4 (10 kW) to Level 1-2 (20 kW), (c)Transition from Level 1-4 (18 kW), Level 2-2 (12 kW), Level 2-4 (10 kW) and Level 1-2 (20 kW).Fig. 10. Experimental setup of the proposed controller and its components.Fig. 9. The experimental set-up of the proposed power-frequency controller.V. E XPERIMENTAL R ESULTSIn order to validate the effectiveness of the proposed controlcircuit for controlling the power transfer in IPT system,
Transactions on Industry Applications 1 A Power-Frequency Controller with Resonance Frequency Tracking Capability . power transfer is controlled through the secondary converter . In the literature, several techniques for power flow control for IPT systems exist, including resonance frequency control [12], power-frequency control [13]-[15
The Frequency Response of a Pd Controller . 92 5.13. The Effect of Adding a Low Pass Filter to a Fractional Differentiator . 94 5.14. The Frequency Response of the Fractional Pid Controller 0.7 0.3 1 1s s C . 95 5.15. The Frequency Response of the Fractional Pid Controller 0.5 0.5
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Fig.4.1 Step response using P controller Fig.4.2 Fig.4.3 Fig.4.4 Fig.4.5 Step response using PID controller Fig.4.6 Comparison of bode plot for smith predictor and PI . Step response of IMC PDF control structure Step response of PDF controller Step response using PI controller Step response using PID controller Step response using PI controller
2 Mirror Frequency Filter 2.1 Mirror Frequency In radio reception using heterodyning in the tuning process, the mirror frequency is an undesired input frequency that is capable of producing the same intermediate frequency (IF) that the desired input frequency produces. It is a potential source of interference to proper reception.
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The RT3607CJ is an IMVP8 compliant CPU power controller which includes two voltage rails : a 4/3/2/1 phase synchronous Buck controller, the CORE VR, a 3/2/1 phase . Controller power supply. Connect this pin to 5V and place a decoupling capacitor 2.2 F at least. The decoupling capacitor is as close to VR controller as possible.
Trimble Survey Controller Procedure Sheet Working with Total Stations and Trimble Survey Controller Create a job on the Controller: -Turn on your Controller and go into Survey Controller Software - -Create a new job by going into Files/New Job -Note to set the Scale Factor to 1.0 when working with a Total Station. Hit Accept to create your new job.
CIE IGCSE Business Studies Paper 1 Summer & Winter 2012 to 2015 . UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the May/June 2012 question paper for the guidance of teachers 0450 BUSINESS STUDIES 0450/11 Paper 1 (Short Answer/Structured Response), maximum raw mark 100 This mark scheme is published as an aid to .
