CN109343647B - Dynamic wireless charging maximum efficiency tracking system and method - Google Patents

Dynamic wireless charging maximum efficiency tracking system and method Download PDF

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CN109343647B
CN109343647B CN201811086563.1A CN201811086563A CN109343647B CN 109343647 B CN109343647 B CN 109343647B CN 201811086563 A CN201811086563 A CN 201811086563A CN 109343647 B CN109343647 B CN 109343647B
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CN109343647A (en
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郑宏
卞瑞
顾雨冰
沈建杨
郭其金
许象明
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Jiangsu University
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Abstract

The invention discloses a dynamic wireless charging maximum efficiency tracking system and a dynamic wireless charging maximum efficiency tracking method, wherein the dynamic wireless charging maximum efficiency tracking system comprises a sending part and a receiving part, wherein the sending part comprises a direct current power supply, a high-frequency inverter, a Magnetic Energy Recovery Switch (MERS), a switch resistor, a parasitic resistor of a transmitting coil and a primary coil which are sequentially connected; the receiving part comprises a secondary coil, an MERS, a parasitic resistor of the receiving coil, a rectifying and filtering circuit, a Boost converter and a battery load which are sequentially connected. In order to overcome dynamic conditions such as mutual inductance change, load change and the like in a dynamic process, on the basis of MERS dynamic compensation, a rectifying and filtering circuit, a Boost converter and a load of a receiving part are regarded as equivalent loads, and a system adjusts an equivalent load value to an optimal load value by adjusting input voltage and judging whether the circuit meets a maximum efficiency tracking criterion or not, so that a Maximum Efficiency Point (MEP) is reached. Therefore, the system has high efficiency and wide application range, and has better economical efficiency and reliability compared with the traditional method.

Description

Dynamic wireless charging maximum efficiency tracking system and method
Technical Field
The invention belongs to the field of power electronics, and particularly relates to a maximum efficiency transmission method based on a dynamic wireless charging system.
Background
Wireless Power Transfer (WPT) has many advantages over conventional wired transmission in the aspects of convenience, reliability, safety, isolation, and operation in a severe environment, and has been successfully applied to static Wireless charging occasions of electric vehicles by transferring energy through coupling of a high-frequency alternating magnetic field between a transmitting Power coil and a receiving Power coil. In order to further solve the problems of the relative position of the coil, the change of the load and the like under the actual condition, dynamic wireless charging becomes a research hotspot at home and abroad, wherein high efficiency is the greatest importance.
In recent years, several control methods have been proposed to maintain high transfer efficiency when coil coupling or load conditions change. They include frequency tracking, impedance matching with inductors or capacitors, and load conversion with DC/DC converters. In the frequency tracking method, the frequency is adjusted in the "over-coupled" region due to the frequency splitting phenomenon to adjust a constant output voltage, but this method is not required in the loosely coupled system. In the impedance matching method, a resonance capacitance is adjusted at a fixed frequency by a relay or a semiconductor switch. Therefore, it can adjust the output voltage by changing the impedance, and keep the constant output voltage, but the impedance matching circuit is complicated and has loss, which is difficult to control. The last method introduces a DC/DC converter on the primary side or the secondary side, which is attracting much attention. This method has two major advantages. First, by inserting a DC/DC converter, the system achieves optimal loading under various coupling and loading conditions. Second, the DC/DC converter of the receiving terminal precisely adjusts the output voltage to a constant value, which is also very desirable in practical industrial and commercial applications. Many DC/DC converter based schemes are proposed but often require power measurements or simply provide a direction of efficiency optimization without accurate efficiency tracking criteria.
Disclosure of Invention
The purpose of the invention is as follows: aiming at the problem of reduction of transmission efficiency under a dynamic condition, the invention provides a dynamic wireless charging maximum efficiency tracking system. The method can keep the system in a high-efficiency state under the dynamic conditions of coil offset, load change and the like.
The technical scheme is as follows: in order to achieve the purpose, the invention adopts the following technical scheme:
the dynamic wireless charging maximum efficiency tracking system is characterized in that a wireless charging circuit comprises a transmitting part and a receiving part, wherein the transmitting part comprises a direct current power supply, a high-frequency inverter, a Magnetic Energy Recovery Switch (MERS), a switch resistor, a parasitic resistor of a transmitting coil and the transmitting coil which are sequentially connected; the receiving part comprises a receiving coil, an MERS, a parasitic resistor of the receiving coil, a rectifying and filtering circuit, a Boost converter and a battery load R which are sequentially connectedL. On the basis of MERS dynamic compensation, a rectifying filter circuit, a Boost converter and a load of a receiving part are regarded as equivalent loads, and the system adjusts the equivalent load value to the optimal load value by adjusting input voltage and judging whether the circuit accords with the maximum efficiency tracking criterion, so that the Maximum Efficiency Point (MEP) is reached.
The input end of the high-frequency inverter is connected to the output end of the direct-current power supply and is used for inverting the direct-current voltage into a high-frequency voltage square wave;
the input ends of the MERS, the switch resistor and the parasitic resistor of the transmitting coil are connected to the output end of the high-frequency inverter and used for primary side dynamic compensation;
the transmitting coil and the receiving coil are symmetrically arranged, and wireless transmission of electric energy is realized in a coupling mode;
the output ends of the parasitic resistors of the MERS and the receiving coil are connected to the input end of the rectifying and filtering circuit;
the input end of the rectification filter circuit is connected to the output end of the receiving coil compensation capacitor and is used for rectifying the alternating current voltage output by the receiving coil compensation capacitor into direct current voltage;
the input end of the Boost converter is connected to the output end of the rectifying and filtering circuit and is used for stabilizing output voltage and tracking maximum efficiency;
the battery load RLIs connected to the output of the Boost converter.
A maximum efficiency tracking method of a dynamic wireless charging system comprises the following steps:
s1, determining system parameters, such as RS1、RS2And VdcAnd calculate
Figure GDA0002888862210000021
Wherein R isS1Representing the sum of the switching resistance of the MOSFETs in the inverter and the parasitic resistance of the transmitting coil; rS2Is the parasitic resistance of the receive coil; vdcIs the output voltage;
s2, applying initial input voltage V to the high-frequency inverterinAnd (5) recording the corresponding duty ratio D at the receiving end. Increase of VinUp to D 00 and an output voltage of Vdc. Where the input voltage and duty cycle are respectively denoted as Vin0And D0；
S3, further slightly increasing VinRecording the occupation of the resultSpace ratio of D1. According to two adjacent points (D)0And Vin0，D1And Vin1) Computing
Figure GDA0002888862210000022
S4, mixing
Figure GDA0002888862210000023
Comparing with β and continuing to execute S5 or S6;
s5, when
Figure GDA0002888862210000024
The system is in an overload state and will reach a maximum efficiency point (V)ino，D0). In this case, MEP tracking is done because dD/dVinWith VinIs increased and decreased, so when V is increased and decreasedinWhen the ratio is increased, the ratio cannot reach beta;
the optimum resistance for maximum efficiency tracking is
Figure GDA0002888862210000031
Wherein ω is coil L1And L2The resonant frequency of (d); m12Is a coil L1And L2Mutual inductance between them.
Under the action of Boost, the general formula of the equivalent load is
RE＝8RL/π2·(1-D2)
Wherein R isLIs a battery load; and D is the duty ratio of the Boost converter.
From the above two formulas, if
Figure GDA0002888862210000032
Then there will never be one that satisfies RE＝RE,optIs subject to an overload condition, the system efficiency follows REIs increased. Thus, when D is 0, REThe maximum value is reached, the efficiency reaches the peak value, and the maximum efficiency point is (V)ino,D0)。
S6, when
Figure GDA0002888862210000033
While the system is in normal load condition, VinStill need to be increased to determine MEP. Repeating S3 until
Figure GDA0002888862210000034
Recording dot (V)ino,D0) At this point maximum efficiency is achieved.
The input voltage of the resonator (L1 and left MERS resonance, L2 and right MERS resonance) is
Figure GDA0002888862210000035
Wherein eta isac/dcIs the efficiency of the rectifier.
Under the condition of optimal load, by regarding D to VPDifferentiating to the first order, we obtain
Figure GDA0002888862210000036
It can be seen that a is a constant with the load RLIs irrelevant.
And is also provided with
Figure GDA0002888862210000037
Wherein VinIs the input voltage of the system. The following can be obtained:
Figure GDA0002888862210000038
therefore, for maximum efficiency tracking, the above formula, which is the efficiency tracking criterion, must be satisfied.
Further, the MERS structure is as follows:
the magnetic energy recovery switch MERS comprises a first switch tube, a second switch tube, a third switch tube, a fourth switch tube and a first direct current capacitor. The first switch tube to each switch tube of the fourth switch tube are respectively connected with a diode in an anti-parallel mode, the drain electrode of the first switch tube is connected with the anode of the first direct current capacitor, the source electrode of the first switch tube is connected with the drain electrode of the third switch tube, the drain electrode of the second switch tube is connected with the anode of the first direct current capacitor, the source electrode of the second switch tube is connected with the drain electrode of the fourth switch tube, the source electrode of the third switch tube is connected with the cathode of the first direct current capacitor, the source electrode of the fourth switch tube is connected with the cathode of the first direct current capacitor, and the two ends of the first electronic capacitor circuit are respectively led out from the source electrode of the first switch tube and the source electrode of the second switch tube.
The MERS adopts indirect voltage control: taking the phase of the input voltage as reference, obtaining a power frequency square wave signal after shifting the phase by beta, and triggering the two groups of switches to be conducted in turn; meanwhile, a turn-off signal is generated, the phase of the turn-off signal lags behind the voltage phase (beta-gamma), gamma is a turn-off angle, and another group of power frequency square wave signals are obtained and are sequentially turned off together with the former and the rear control switch. The indirect voltage control respectively adjusts beta and gamma, the variable range of the capacitor is enlarged, and meanwhile, the peak value of the voltage of the capacitor end shows a decreasing trend along with the increase of the gamma, so that the effect of inhibiting the voltage of the capacitor can be achieved.
The invention has the following beneficial effects: the invention discloses a dynamic wireless charging maximum efficiency tracking system. By adjusting the system input voltage VinCalculating dD/dVinComparing it with the proposed tracking criterion, if the tracking criterion is met, the maximum efficiency tracking can be achieved in a dynamic system. And dynamic compensation is implemented using MERS. Compared with the traditional method, the method only needs to measure VinD, no extra equipment is needed for measuring power and the like, so that the cost is low; and given specific efficiency tracking criteria, can thereforeThe maximum efficiency under different conditions can be accurately tracked, and the tracking effect is better.
Drawings
FIG. 1: the invention provides a system block diagram of a dynamic wireless charging maximum efficiency tracking system;
FIG. 2: the flow chart of MET proposed by the invention;
FIG. 3: the MERS structure diagram provided by the invention;
FIG. 4: primary voltage and current waveforms;
FIG. 5: secondary side voltage and current; (a) a voltage waveform; (b) a current waveform;
FIG. 6: a graph of the fluctuation in efficiency with changes in load and coupling coefficients; (a) k is 0.36, RL(ii) a change; (b) k is 0.3, RL(ii) a change; (c) k is 0.24, RLAnd (4) changing.
Detailed Description
The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.
Fig. 1 is a general structural diagram of a dynamic wireless charging maximum efficiency tracking system, where a wireless charging circuit includes a transmitting part and a receiving part, the transmitting part includes a dc power supply, a high-frequency inverter, a Magnetic Energy Recovery Switch (MERS), a switch resistor, a parasitic resistor of a transmitting coil, and a transmitting coil, which are connected in sequence; the receiving part comprises a receiving coil, an MERS, a parasitic resistor of the receiving coil, a rectifying and filtering circuit, a Boost converter and a battery load R which are sequentially connectedL. On the basis of MERS dynamic compensation, a rectifying filter circuit, a Boost converter and a load of a receiving part are regarded as equivalent loads, and the system adjusts the equivalent load value to the optimal load value by adjusting input voltage and judging whether the circuit accords with the maximum efficiency tracking criterion, so that the Maximum Efficiency Point (MEP) is reached.
Further, the input end of the high-frequency inverter is connected to the output end of the direct-current power supply and used for inverting the direct-current voltage into a high-frequency voltage square wave;
furthermore, the input ends of the MERS, the switch resistor and the parasitic resistor of the transmitting coil are connected to the output end of the high-frequency inverter and used for primary side dynamic compensation;
furthermore, the transmitting coil and the receiving coil are symmetrically arranged, and wireless transmission of electric energy is realized in a coupling mode;
further, the output ends of the parasitic resistors of the MERS and the receiving coil are connected to the input end of the rectifying and filtering circuit;
furthermore, the input end of the rectifying and filtering circuit is connected to the output end of the receiving coil compensation capacitor, and is used for rectifying the alternating-current voltage output by the receiving coil compensation capacitor into direct-current voltage;
furthermore, the input end of the Boost converter is connected to the output end of the rectifying and filtering circuit and is used for stabilizing the output voltage and tracking the maximum efficiency;
further, the battery load RLIs connected to the output of the Boost converter.
Fig. 2 shows a flow chart of a maximum power tracking method, which includes the following steps:
s1, determining system parameters, such as RS1、RS2And VdcAnd calculate
Figure GDA0002888862210000051
Wherein R isS1Representing the sum of the switching resistance of the MOSFETs in the inverter and the parasitic resistance of the transmitting coil; rS2Is the parasitic resistance of the receive coil; vdcIs the output voltage. Beta is a critical value of the tracking criterion and is a constant, namely the tracking criterion is constant and unique;
s2, applying initial input voltage V to the high-frequency inverterinAnd (5) recording the corresponding duty ratio D at the receiving end. Increase of VinUp to D 00 and an output voltage of Vdc. Where the input voltage and duty cycle are respectively denoted as Vin0And D0；
S3, further slightly increasing VinThe duty ratio of the recorded result is D1. According to two adjacent points (D)0And Vin0，D1And Vin1) Computing
Figure GDA0002888862210000061
S4, mixing
Figure GDA0002888862210000062
Comparing with beta, namely judging whether the tracking criterion is met and continuing to execute S5 or S6;
s5, when
Figure GDA0002888862210000063
The system is in an overload state and will reach a maximum efficiency point (V)ino,D0). In this case, MEP tracking is done because dD/dVinWith VinIs increased and decreased, so when V is increased and decreasedinWhen the ratio is increased, the ratio cannot reach beta;
the optimum resistance for maximum efficiency tracking is
Figure GDA0002888862210000064
Wherein ω is coil L1And L2The resonant frequency of (d); m12Is a coil L1And L2Mutual inductance between them.
Under the action of Boost, the general formula of the equivalent load is
RE＝8RL/π2·(1-D2) (4)
Wherein R isLIs a battery load; and D is the duty ratio of the Boost converter.
From the above two formulas, if
Figure GDA0002888862210000065
Then there will never be one that satisfies RE＝RE,optIs subject to an overload condition, the system efficiency follows REIs increased. Thus, when D is 0, REThe maximum value is reached, the efficiency reaches the peak value, and the maximum efficiency point is (V)ino,D0)。
S6, when
Figure GDA0002888862210000066
While the system is in normal load condition, VinStill need to be increased to determine MEP. Repeating S3 until
Figure GDA0002888862210000067
Recording dot (V)ino,D0) At this point maximum efficiency is achieved.
The input voltage of the resonator is
Figure GDA0002888862210000068
Wherein eta isac/dcIs the efficiency of the rectifier.
Under the condition of optimal load, by regarding D to VPDifferentiating to the first order, we obtain
Figure GDA0002888862210000069
It can be seen that a is a constant with the load RLIs irrelevant.
And is also provided with
Figure GDA0002888862210000071
Wherein VinIs the input voltage of the system. The following can be obtained:
Figure GDA0002888862210000072
therefore, for maximum efficiency tracking, the above formula, which is the efficiency tracking criterion, must be satisfied.
As shown in fig. 3, the MERS includes a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, and a first dc capacitor. Each switch tube from the first switch tube to the fourth switch tube is respectively connected with a diode in an anti-parallel mode, the drain electrode of the first switch tube is connected with the anode of the first direct-current capacitor, the source electrode of the first switch tube is connected with the drain electrode of the third switch tube, the drain electrode of the second switch tube is connected with the anode of the first direct-current capacitor, the source electrode of the second switch tube is connected with the drain electrode of the fourth switch tube, the source electrode of the third switch tube is connected with the cathode of the first direct-current capacitor, the source electrode of the fourth switch tube is connected with the cathode of the first direct-current capacitor, and two ends of the first electronic capacitor circuit are respectively led out from the source electrode of the first switch tube and the source electrode of the second switch tube.
The MERS adopts an indirect voltage control method, which comprises the following steps:
taking the phase of the input voltage as reference, obtaining a power frequency square wave signal after shifting a trigger angle beta, and triggering the two groups of switches to be conducted in turn; meanwhile, a turn-off signal is generated, the phase of the turn-off signal lags behind the voltage phase (beta-gamma), gamma is a turn-off angle, another group of power frequency square wave signals are obtained, and the signals are subjected to AND with the former signals and then the control switch is turned off in sequence. The indirect voltage control respectively adjusts beta and gamma, the variable range of the capacitor is enlarged, and meanwhile, the peak value of the voltage of the capacitor end shows a trend of reducing along with the increase of the turn-off angle gamma, so that the effect of restraining the voltage of the capacitor can be achieved. However, the farther the operating point is displaced from the equilibrium position, the more distorted the current waveform becomes.
Fig. 6 shows the efficiency comparison of the system proposed herein with a generic architecture system in a dynamic situation. In theory, once the method finds the optimum load for maximum transfer efficiency, the transfer efficiency will remain the same even at different loads. But since the efficiency of the inverter decreases slightly with increasing load (since the load power decreases but the switching losses are almost constant), the system efficiency will follow RLIs increasedPlus and slightly lower. However, if this method is not used, the transmission efficiency will follow R since the optimum load is not metLIs increased and sharply decreased. The results show that the efficiency of the proposed system is significantly higher than that of the conventional system.
In summary, the system and method for tracking maximum efficiency of dynamic wireless charging of the present invention includes a transmitting part and a receiving part, wherein the transmitting part includes a dc power supply, a high frequency inverter, a Magnetic Energy Recovery Switch (MERS), a switch resistor, a parasitic resistor of a transmitting coil, and a transmitting coil, which are connected in sequence; the receiving part comprises a receiving coil, an MERS, a parasitic resistor of the receiving coil, a rectifying and filtering circuit, a Boost converter and a battery load R which are sequentially connectedL. In order to overcome dynamic conditions such as mutual inductance change, load change and the like in a dynamic process, on the basis of MERS dynamic compensation, a rectifying and filtering circuit, a Boost converter and a load of a receiving part are regarded as equivalent loads, and a system adjusts an equivalent load value to an optimal load value by adjusting input voltage and judging whether the circuit meets a maximum efficiency tracking criterion or not, so that a Maximum Efficiency Point (MEP) is reached. In addition, the invention only needs to measure the input voltage and the duty ratio of the Boost converter, and does not need extra equipment to measure power and the like. Therefore, the system has high efficiency and wide application range, and has better economical efficiency and reliability compared with the traditional method. Simulation results show that the efficiency of the structure provided by the method is higher than that of a common series structure by more than 40% under the dynamic condition.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (3)

1. The maximum efficiency tracking method of the dynamic wireless charging system is characterized in that a wireless charging circuit comprises a transmitting part and a receiving part;
the transmitting part comprises a direct current power supply, a high-frequency inverter, a magnetic energy recovery switch MERS, a switch resistor, a parasitic resistor of the transmitting coil and the transmitting coil which are connected in sequence; the input ends of the magnetic energy recovery switch MERS, the switch resistor and the parasitic resistor of the transmitting coil are connected to the output end of the high-frequency inverter and used for primary side dynamic compensation;
the receiving part comprises a receiving coil, a magnetic energy recovery switch MERS, a parasitic resistor of the receiving coil, a rectifying and filtering circuit, a Boost converter and a battery load R which are sequentially connectedL(ii) a The output ends of the magnetic energy recovery switch MERS and the parasitic resistor of the receiving coil are connected to the input end of the rectifying and filtering circuit, and the input end of the Boost converter is connected to the output end of the rectifying and filtering circuit and used for stabilizing output voltage and tracking maximum efficiency; the battery load RLThe input end of the Boost converter is connected to the output end of the Boost converter; on the basis of MERS dynamic compensation, a rectifying and filtering circuit, a Boost converter and a battery load RLWhen the equivalent load is regarded as the equivalent load, the system adjusts the equivalent load value to the optimal load value by adjusting the input voltage and judging whether the circuit accords with the maximum efficiency tracking criterion, so that the maximum efficiency point MEP is reached;
the magnetic energy recovery switch MERS comprises a first switch tube, a second switch tube, a third switch tube, a fourth switch tube and a first direct current capacitor; each of the first switch tube to the fourth switch tube is connected with a diode in an anti-parallel mode, a drain electrode of the first switch tube is connected with an anode of a first direct current capacitor, a source electrode of the first switch tube is connected with a drain electrode of a third switch tube, a drain electrode of the second switch tube is connected with an anode of the first direct current capacitor, a source electrode of the second switch tube is connected with a drain electrode of the fourth switch tube, a source electrode of the third switch tube is connected with a cathode of the first direct current capacitor, a source electrode of the fourth switch tube is connected with a cathode of the first direct current capacitor, and two ends of the first direct current capacitor are led out from the source electrode of the first switch tube and the source electrode of the second switch tube respectively;
the magnetic energy recovery switch MERS adopts indirect voltage control, takes the phase of input voltage as reference, obtains a power frequency square wave signal after shifting the phase beta, and triggers the two groups of switches to be conducted in turn; meanwhile, a turn-off signal is generated, the phase lag voltage phase of the turn-off signal is beta-gamma, gamma is a turn-off angle, and another group of power frequency square wave signals are obtained and are sequentially turned off together with the former and the rear control switch; the indirect voltage control adjusts beta and gamma respectively, the variable range of the capacitor is enlarged, and meanwhile, the peak value of the voltage of the capacitor end shows a decreasing trend along with the increase of gamma;
the transmitting coil and the receiving coil are symmetrically arranged, and wireless transmission of electric energy is realized in a coupling mode;
the input end of the high-frequency inverter is connected to the output end of the direct-current power supply and is used for inverting the direct-current voltage into a high-frequency voltage square wave;
the input end of the rectification filter circuit is connected to the output end of the transmitting coil compensation capacitor and is used for rectifying the alternating current voltage output by the receiving coil compensation capacitor into direct current voltage;
the method comprises the following steps:
s1, determining RS1、RS2And VdcThese system parameters, and calculate the threshold β of the tracking criterion:
Figure FDA0002935577100000021
wherein R isS1Representing the sum of the switching resistance of the MOSFETs in the inverter and the parasitic resistance of the transmitting coil; rS2Is the parasitic resistance of the receive coil; vdcIs the output voltage;
s2, forHigh frequency inverter applying an initial input voltage Vin0, and recording the corresponding duty ratio D at the receiving end, and increasing VinUp to D00 and an output voltage of VdcWhere the input voltage and duty cycle are respectively denoted by Vin0And D0；
S3, increasing V furtherinThe duty ratio of the recorded result is D1According to two adjacent points D0And Vin0、D1And Vin1And (3) calculating:
(dD/dVin)|D0＝(D1-D0)/ΔV；
s4, mixing (dD/dV)in)|D0Comparing with β and continuing to execute S5 or S6;
s5, when (dD/dV)in)|D0Beta is less than or equal to beta, the system is in an overload state, and the maximum efficiency point (V) is reachedino,D0) In this case, MEP tracking is done because dD/dVinWith VinIs increased and decreased, so when V is increased and decreasedinWhen the ratio is increased, the ratio cannot reach beta;
s6, when (dD/dV)in)|D0When beta is greater than beta, the system is in a normal load state, VinStill to be increased to determine MEP, S3 is repeated until (dD/dV)in)|D0Beta is less than or equal to beta; recording dot (V)ino,D0) At this point maximum efficiency is achieved.
2. The method for tracking maximum efficiency of a dynamic wireless charging system according to claim 1, wherein in S5, the specific analysis process of the overload state is as follows:
the optimum resistance for maximum efficiency tracking is
Figure FDA0002935577100000022
Wherein ω is coil L1And L2The resonant frequency of (d); m12Is a coil L1And L2Mutual inductance between them;
under the action of a Boost converter, the general formula of an equivalent load is as follows:
RE＝8RL/π2·(1-D2)
wherein R isLIs a battery load; d is the duty ratio of the Boost converter;
from the above two formulas, if
Figure FDA0002935577100000031
Then none will satisfy RE＝RE,optIs subject to an overload condition, the system efficiency follows REIs increased, when D is 0, R isEThe maximum value is reached, the efficiency reaches the peak value, and the maximum efficiency point is (V)ino,D0)。
3. The method for tracking maximum efficiency of a dynamic wireless charging system according to claim 1, wherein in S6, the tracking criterion of maximum efficiency is satisfied:
Figure FDA0002935577100000032
wherein the content of the first and second substances,
Figure FDA0002935577100000033
therefore, for maximum efficiency tracking, the above formula, which is the efficiency tracking criterion, must be satisfied.
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JP4441691B2 (en) * 2007-02-06 2010-03-31 国立大学法人東京工業大学 AC / DC power converter
WO2009139077A1 (en) * 2008-05-15 2009-11-19 国立大学法人 東京工業大学 Alternating voltage control unit
JP2011044036A (en) * 2009-08-21 2011-03-03 Tokyo Institute Of Technology Ac current controller and control method and program for ac current
CN106740238B (en) * 2017-02-20 2023-08-25 华南理工大学 Wireless charging circuit of electric automobile and control method thereof
CN106972647A (en) * 2017-05-02 2017-07-21 华中科技大学 A kind of method for improving dynamic radio charging average efficiency

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