CN117040144A - Frequency tuning and power flow decoupling control method and system of BCPT system - Google Patents
Frequency tuning and power flow decoupling control method and system of BCPT system Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
- H02J50/05—Circuit arrangements or systems for wireless supply or distribution of electric power using capacitive coupling
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
- H02J50/80—Circuit arrangements or systems for wireless supply or distribution of electric power involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/01—Resonant DC/DC converters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
- H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
- H02M3/33584—Bidirectional converters
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Abstract
The invention relates to the technical field of electric field coupling type wireless power transmission, and particularly discloses a frequency tuning and power flow decoupling control method and system of a BCPT system, which ensure that the BCPT system is in a resonance state before bidirectional power flow adjustment, so that the preset power size and direction are achieved when phase shift adjustment is performed. The frequency tuning and power flow decoupling control method and system are characterized in that the working frequency of the BCPT system is regulated by detecting and comparing the phase difference of primary side resonance current and resonance voltage and tracking the resonance frequency so as to correct the phase relation of voltage and current among circuit components, and then the relative phase angle or amplitude of the primary side converter resonance voltage and the secondary side converter resonance voltage is controlled to regulate the size and direction of expected power of the system, so that the decoupling between the frequency tuning and the bidirectional power flow regulation of the system is realized, and the stable power regulation of the system is ensured. And finally, verifying the effectiveness of the frequency tuning and bidirectional power flow decoupling control method of the BCPT system through simulation and experimental results.
Description
Technical Field
The invention relates to the technical field of electric field coupling type wireless power transmission, in particular to a frequency tuning and power flow decoupling control method and system of a BCPT (electric field coupling type bidirectional wireless power transmission) system.
Background
The wireless power transmission (Wireless Power Transfer, WPT) technology refers to a technology for comprehensively applying an electrotechnology theory, a power electronic technology and a control theory and realizing the transmission of power from a power grid or a battery to electric equipment in a non-electric contact manner by utilizing a magnetic field, an electric field, microwaves or laser and the like, so that the problems of unsafe and inflexible power contacts are solved. Over the past few years, the theory and technology of inductive wireless power transfer (Inductive Power Transfer, IPT) has been widely studied and applied. However, IPT systems cannot transfer power through metal obstructions due to electromagnetic shielding, and power losses are severe when metal objects are close to the magnetic field. Capacitive wireless power transfer (Capacitive Power Transfer, CPT) technology uses an electric field as an energy transfer medium, and can transfer energy across metals without consideration of metal interference. In addition, the electric field of the CPT system is mainly concentrated between the coupling polar plates, the surrounding electromagnetic interference is greatly reduced, the CPT system has the unique advantages of light coupling structure, small eddy current loss, low system cost and the like, and the electric field is similar to the magnetic field in many characteristics, and the electric field and the magnetic field show duality in the basic theory, so that the CPT system also increasingly draws high attention of expert scholars at home and abroad. Currently, CPT systems have achieved some research results in applications such as LED lights, biomedical devices, mobile robots, bioelectric measurement systems, and electric car charging.
At the same timeMore and more scenarios begin to show a need for two-way wireless power transfer (Bidirectional Wireless Power Transfer, BWPT) technology, where consumers want their consumers to be able to easily share power wirelessly, such as Vehicle-to-grid (V2G) applications and portable consumer charging. BCPT technology is a BWPT technology, and is considered as a potential development trend. A block diagram of a typical BCPT system is shown in FIG. 1, where V d Representing the direct voltage produced by a single-phase network through an active rectifier, V o Representing the battery voltage. The power grid power side is generally used as the primary side of the system, and the battery direct-current voltage side is generally used as the secondary side of the system. High frequency transducers on the primary and secondary sides of the system are used to drive the coupling mechanism and compensation network.
BCPT systems typically use the same symmetrical active converter (reversible rectifier) and compensation topology. Typically, the power level and direction of the system is controlled by the relative phase angle or amplitude of the ac voltage produced by the primary and secondary side converters. In practical applications of bi-directional wireless power transfer systems for electric vehicles, consumer electronics, or industrial manufacturing, these charging systems can be bi-directional wireless charged by electric field coupling, and alignment between the coupled plates is critical to ensure efficient charging at the desired power level. However, misalignment or offset is inevitably caused between the coupling plates, resulting in a change in system parameters, which results in very adverse effects such as unstable system and reduced power transmission. This is because when the consumer is charged wirelessly with the desired power, the bi-directional wireless charging system becomes detuned due to the variation of the coupling capacitance caused by the misalignment of the plates, which results in a change in the vector relationship of the voltage and current between the circuit components, and the aforementioned relative phase angle or magnitude of the ac voltage generated by the primary and secondary side converters may deviate to control the system power magnitude and direction, such that the BCPT system reduces the charging power level and even transmits power against the desired power flow direction.
Several approaches have been proposed and implemented to address this problem in two-way wireless power transfer applications, including mainly the use of novel hybrid topologies, power control strategies, etc. There are documents that propose a BWPT system that adopts a hybrid topology of two LCLs and CL resonant networks connected in parallel, and that can charge an electric vehicle at a constant rate in the case of misalignment between coupling mechanisms, realizing a constant and efficient charging process. However, without any active control, employing such a topology is inherently complex and susceptible to power fluctuations. There is literature that proposes a bi-directional power flow control strategy based on an interference observation method. By applying interference to the relative phase angle: if the power is changed in the desired direction, the relative phase angle will continue to increase or decrease in the same direction, otherwise will change in the opposite direction. The control method can improve the influence of parameter variation and system detuning, but the power can always fluctuate under the interference of a phase angle, and the stability of the system is influenced. There is also literature that zero reactive power control of BWPT systems is achieved by detecting the system active, reactive power and thereby eliminating the frequency error. Although the method can always keep reactive power of the system to be zero when the coupling coils are misplaced, and can effectively regulate the power flow of the system. However, the zero reactive power control and the bidirectional power flow regulation of the system simultaneously use the phase angle adjustment of the phase shift between the switching tubes of the converter, and the coupling between the zero reactive power control and the bidirectional power flow regulation can be generated, especially for the coupling condition in the CPT high-frequency system.
Disclosure of Invention
The invention provides a control method and a control system for frequency tuning and power flow decoupling of a BCPT system, which solve the technical problems that: aiming at the unexpected detuning situation caused by the dislocation or offset of the coupling polar plate possibly existing in the BCPT system, how to accurately and effectively realize the expected power flow adjustment without increasing a complex topological structure.
In order to solve the technical problems, the invention provides a frequency tuning and power flow decoupling control method of a BCPT system, wherein the BCPT system, namely an electric field coupling bidirectional wireless power transmission system, comprises a primary side and a secondary side, and the primary side comprises a primary side direct current voltage V which is sequentially connected d Primary side converter, primary side compensation network, primary side coupling polar plate, the secondary side includes secondary side coupling polar plate connected in sequenceBoard, secondary side compensation network, secondary side converter and secondary side DC voltage V o The key point is that the control method comprises the following steps:
s1, at the initial time, toDelta = 90 °, switching drive frequency f s The BCPT system is operated, and the system transmits power in the forward direction, < >>Respectively representing internal phase shift angles of the primary side converter and the secondary side converter, wherein delta represents an adjustable delay phase shift angle of the primary side converter;
S2, adjusting the switching driving frequency of the BCPT system to enable the primary side resonant current i to be 1 And the output voltage v of the primary side converter p The phase difference between them is 0;
s3, adjustingAnd delta, so that the power magnitude and direction of the BCPT system is the magnitude and direction of the expected power of the system.
Further, the step S2 specifically includes the steps of:
s21, detecting primary side resonance current i 1 And primary resonance voltage v p Obtaining i 1 And v p A phase difference between them;
s22, judging i 1 And v p If the phase difference is 0, a new switching driving frequency is generated to act on the BCPT system according to the phase difference if the phase difference is not 0, and if the phase difference is 0, the step S3 is performed.
Further, the step S3 specifically includes the steps of:
s31, collecting secondary side direct current I o And secondary side DC voltage V o Calculating power P of BCPT system o ＝I o *V o ；
S32, calculating P o And system expected power P e A difference between them;
s33, judging whether the power difference is 0, if so, keeping the current system parameters to operate, and if not, calculating a relative phase angle according to the power difference and entering the next step;
s34, adjusting according to the calculated relative phase angleAnd delta, leading the primary side resonance voltage v p And secondary resonance voltage v r The relative phase difference between them is such that the desired power P of the system is met e 。
Further, in said step S3, in the adjusting stepAnd delta, if the secondary side direct current I is detected o Sudden rise or fall, the regulation is stopped +.>And δ and returns to step S1.
Further, in said step S33, the relative phase angle is calculated based on the following principle:
the power transfer expressions of the primary side and the secondary side are:
wherein P is p 、P r Representing the transmission power, ω, of the primary side and the secondary side, respectively c Representing the resonant angular frequency of the system as well as the operating angular frequency, C 1 Representing primary resonance compensation capacitance, C in primary LC-type compensation network 2 Representing secondary side resonance compensation capacitance, C in a secondary side LC type compensation network s Representing the equivalent coupling capacitance between the primary side coupling plate and the secondary side coupling plate, V p 、V r Representing the effective values of the primary and secondary resonance voltages, respectively, θ representing the relative phase angle, i.e., primary resonance voltage v p And secondary resonance voltage v r A relative phase difference between them; p when θ∈ (0, pi) p >0，P r <0, the retarded relative phase angle enables energy transfer from primary side to secondary side, system forward power transfer; when θ∈ (-pi, 0), P p <0，P r >0, the leading relative phase angle enables energy transfer from the secondary side to the primary side, the system reversing power transfer;
In the step S34, the adjustment is based on the following relationAnd delta, such that the primary resonance voltage v p And secondary resonance voltage v r The relative phase difference therebetween satisfies the calculated relative phase angle:
wherein β represents an adjustable delay phase shift angle of the secondary side converter.
The invention also provides a frequency tuning and power flow decoupling control system of the BCPT system, which is characterized in that: the primary side controller is connected with the primary side converter, and the secondary side controller is connected with the secondary side converter;
the primary side controller and the secondary side controller are used for at the initial momentDelta = 90 °, switching drive frequency f s The BCPT system is operated, and the system transmits power in the forward direction, < >>Respectively representing internal phase shift angles of the primary side converter and the secondary side converter, wherein delta represents an adjustable delay phase shift angle of the primary side converter;
the primary side controller and the secondary side controller are also used for adjusting the switching driving frequency of the BCPT system so as to lead the primary side resonant current i to be 1 And the output voltage v of the primary side converter p The phase difference between them is 0;
the secondary side controller is also used for adjustingAnd delta, so that the power magnitude and direction of the BCPT system is the magnitude and direction of the expected power of the system.
Specifically, the primary side controller and the secondary side controller are further configured to adjust a switching driving frequency of the BCPT system, so that a primary side resonant current i 1 And the output voltage v of the primary side converter p The phase difference between the two is 0, specifically comprising:
the primary side controller detects primary side resonance current i 1 And primary resonance voltage v p Obtaining i 1 And v p A phase difference between them;
the primary side controller judges i 1 And v p If the phase difference is 0, generating a new switching driving frequency to act on the primary side converter according to the phase difference, and transmitting the new switching driving frequency to the secondary side controller; if the tuning is 0, sending a message that tuning is completed to the secondary side controller;
the secondary side controller works with the new switch driving frequency if receiving the new switch driving frequency; and if the message that the tuning is completed is received, the operation is performed at the original switch driving frequency.
Specifically, the secondary side controller is also used for adjustingAnd delta, enabling the power magnitude and direction of the BCPT system to be the magnitude and direction of the expected power of the system, and specifically comprising:
the secondary side controller collects secondary side direct current I o And secondary side DC voltage V o Calculating power P of BCPT system o ＝I o *V o ；
The secondary side controller calculates P o And system expected power P e A difference between them;
the secondary side controller judges whether the power difference is 0, if so, the current system parameter operation is kept, otherwise, the current system parameter operation is kept according to the power differenceCalculating the relative phase angle from the values and adjusting based on the relative phase angleAnd delta, leading the primary side resonance voltage v p And secondary resonance voltage v r The relative phase difference between them is such that the desired power P of the system is met e 。
Specifically, the secondary side controller is adjustingIn the delta process, the secondary side direct current I is detected in real time o If the secondary DC current I is detected o Sudden rise or fall, the regulation is stopped +.>And delta.
Specifically, the secondary side controller calculates the relative phase angle based on the following principle:
the power transfer expressions of the primary side and the secondary side are:
wherein P is p 、P r Representing the transmission power, ω, of the primary side and the secondary side, respectively c Representing the resonant angular frequency of the system as well as the operating angular frequency, C 1 Representing primary resonance compensation capacitance, C in primary LC-type compensation network 2 Representing secondary side resonance compensation capacitance, C in a secondary side LC type compensation network s Representing the equivalent coupling capacitance between the primary side coupling plate and the secondary side coupling plate, V p 、V r Representing the effective values of the primary and secondary resonance voltages, respectively, θ representing the relative phase angle, i.e., primary resonance voltage v p And secondary resonance voltage v r A relative phase difference between them; p when θ∈ (0, pi) p >0，P r <0, the retarded relative phase angle enables energy transfer from primary side to secondary side, system forward power transfer; when θ∈ (-pi, 0), P p <0，P r >0, the leading relative phase angle enables energy transfer from the secondary side to the primary side, the system reversing power transfer;
the secondary side controller adjusts based on the following relationshipAnd delta, such that the primary resonance voltage v p And secondary resonance voltage v r The relative phase difference therebetween satisfies the calculated relative phase angle:
wherein β represents an adjustable delay phase shift angle of the secondary side converter.
The frequency tuning and power flow decoupling control method and system of the BCPT system ensure that the BCPT system is in a resonance state before bidirectional power flow adjustment, thereby reaching the preset power size and direction when phase shift adjustment is carried out. The frequency tuning and power flow decoupling control method and system are used for adjusting the working frequency of the BCPT system by detecting and comparing the phase difference of primary side resonance current and resonance voltage and tracking the resonance frequency so as to correct the phase relation of voltage and current among circuit components, and then controlling the relative phase angle or amplitude of the primary side converter resonance voltage and the secondary side converter resonance voltage so as to adjust the size and the direction of expected power of the system. This not only decouples the system frequency tuning from the bi-directional power flow adjustment but also ensures that the system is able to tune work steadily. And finally, verifying the effectiveness of the frequency tuning and bidirectional power flow decoupling control method and system of the BCPT system through simulation and experimental results.
Drawings
FIG. 1 is a circuit topology of a typical BCPT system provided in the background of the invention;
fig. 2 is a circuit topology diagram of a double-sided LC resonant network BCPT system and a control system thereof provided by an embodiment of the present invention;
FIG. 3 is a diagram of switching sequences and resonant voltage waveforms of primary and secondary side converters of the system according to an embodiment of the present invention;
FIG. 4 shows a simplified equivalent AC side circuit model of a BCPT system according to an embodiment of the present invention, wherein (a) is a simplified resonant circuit topology and (b) is a primary side resonant voltage V p Excitation circuit diagram, (c) is secondary resonance voltage V r An excitation circuit diagram;
FIG. 5 is a phase relationship diagram of system transmission power versus relative phase angle provided by an embodiment of the present invention;
FIG. 6 is a graph of current and voltage phasor relationships between circuit components in the case of complete alignment and misalignment of the coupling plates provided by an embodiment of the present invention, where (a) is when the system is in resonance and (b) is when the system is out of resonance;
FIG. 7 shows an equivalent coupling capacitor C according to an embodiment of the present invention s When changing, Y rr Amplitude and Y of (2) pr Phase angle and resonant frequency f of (2) c Is a relationship diagram of (1);
FIG. 8 is a simplified block diagram of a BCPT system and a frequency tuning and power flow decoupling control system thereof provided by an embodiment of the present invention;
Fig. 9 is a flowchart of a method for controlling frequency tuning and power flow decoupling of a BCPT system according to an embodiment of the present invention;
FIG. 10 is a block diagram of a frequency tuning and bi-directional power flow adjustment control provided by an embodiment of the present invention, wherein (a) corresponds to frequency tuning and (b) corresponds to bi-directional power flow adjustment;
FIG. 11 is a diagram of a circuit waveform in a system resonant and non-resonant state according to an embodiment of the present invention, where (a) corresponds to the circuit waveform in the resonant state and (b) corresponds to the circuit waveform in the non-resonant state;
FIG. 12 is a graph showing the variation of the system resonant frequency and the coupling capacitance with the displacement of the coupling plates in the experiment provided by the embodiment of the invention, wherein (a) the corresponding plate distance varies, and (b) the corresponding plate is laterally shifted;
FIG. 13 is a diagram of frequency tuning and power flow adjustment for plate misalignment in an experiment provided by an embodiment of the present invention;
fig. 14 is a graph of frequency tuning and power flow regulation as the plate spacing varies in an experiment provided by an embodiment of the present invention.
Detailed Description
The following examples are given for the purpose of illustration only and are not to be construed as limiting the invention, including the drawings for reference and description only, and are not to be construed as limiting the scope of the invention as many variations thereof are possible without departing from the spirit and scope of the invention.
In order to conveniently realize energy supply and demand and sharing among electric equipment, a circuit topology of a frequency tuning and power flow decoupling control system based on a double-side LC resonance network BCPT system and the BCPT system provided by the invention is shown in figure 2. The BCPT system, namely the electric field coupling bidirectional wireless power transmission system, comprises a primary side and a secondary side, wherein the primary side comprises primary side direct current voltage V which are sequentially connected d The primary side comprises a secondary side coupling polar plate, a secondary side compensation network, a secondary side converter and a secondary side direct current voltage V which are sequentially connected o . The frequency tuning and power flow decoupling control system of the BCPT system comprises a primary side controller connected with the primary side converter and a secondary side controller connected with the secondary side converter. Under the action of the interaction electric field, the BCPT system realizes wireless electric energy transmission between polar plates, in order to simplify analysis, the primary side direct current source input is provided by a power grid side or a direct current power supply, the secondary side is an electric equipment battery, and output interfaces at two ends of the BCPT system are all represented by the direct current power supply. The primary and secondary circuits employ nearly identical converters and resonant networks to facilitate bi-directional power flow between powered devices, including full-bridge converters (reversible rectifiers) and bilateral LC resonant networks. Each full-bridge converter operates in an inverter or rectifier mode, depending on the direction of system power flow.
The resonant tank of fig. 2 adopts a double-sided LC compensation structure, and since this compensation structure is simple, only two external passive elements can be applied for short-distance and long-distance applications, and the transmission efficiency can be optimized to a relatively high level. Wherein L is 1 And L 2 To compensate coil self-inductance, C 1 And C 2 Compensating the capacitance for resonance. v p And v r Is the output voltage of the primary and secondary side converters, i 1 And i 2 For the current of the resonant circuit, V d And V o Respectively is the direct current voltage at two ends of the circuit, C d And C o Is a direct current filter capacitor. Coupling polar plate P 1 And P 2 Placed on the primary side, polar plate P 3 And P 4 The electric energy is transmitted between the polar plates in a wireless way under the interaction of the electric fields. Polar plate P 1 ,P 3 And P 2 ,P 4 Respectively form coupling capacitors C s1 And C s2 And equivalent coupling capacitance C s Can be derived as C s ＝C s1 ×C s2 /(C s1 +C s2 )。
The high-frequency full-bridge converters of the primary side and the secondary side of the BCPT system are driven by two synchronous controllers, the primary side controller and the secondary side controller both adopt a phase shifting technology, and the primary side controller generates an internal phase shifting angle for the primary side converterThe secondary side controller generates an internal phase shift angle +.>The output voltages of the primary and secondary side converters are adjusted. In addition, δ and β are adjustable delay phase shifts between the secondary side control signal and the primary side control signal. Then, the relative phase difference of the output voltages of the primary and secondary side converters can be expressed as θ, and the switching timing and resonance voltage waveform diagrams of the primary and secondary side converters of the system are shown in fig. 3. The switching tubes (S1-S4, S5-S8) of the primary-secondary converter have a duty ratio of 50% and a switching frequency f s Operates to generate a resonant voltage v p And v r . Thus, the full bridge converter output voltage can be derived by fourier series expansion:
wherein omega s ＝2πf s Is in combination withf s The corresponding angular frequency, n, represents the number of fourier series.
The circuit diagram in fig. 2 can be further simplified into two voltage sources V p 、V r And an impedance network circuit, the simplified equivalent ac side circuit model is shown in fig. 4. Fig. 4 (a) exhibits a simplified resonant circuit topology. Using the superposition theorem for analyzing the circuit, fig. 4 (b) shows the voltage V at the primary side p The excited circuit model, while FIG. 4 (c) shows the driven secondary voltage V r Excited circuit model. Calculation of the voltage source V p Or V r When a current is generated, another voltage source is replaced by a short circuit. Thus, the resonant current expression for the primary and secondary sides can be given by:
wherein V is p 、V r Is the voltage generated by the full-bridge converter at the fundamental wave frequency, and the equivalent admittance Y pp And Y rr From the primary voltage V p And secondary side voltage V r Excitation alone gives admittance Y rp And Y pr Respectively for calculating the V r The generated current I 1r And by V p And the current I is generated 2p . The equivalent admittance can be expressed as:
wherein the impedance of the corresponding capacitance and inductance in the circuit is defined as Z C1 、Z C2 、Z Cs 、Z L1 And Z L2 Expressed as:
Thus, the transmission power expression of the system can be given by:
where Re { } represents the real part and the upper right "×" represents the effective value of the parameter.
The frequency of the double-sided LC resonance circuit of the BCPT system is omega c Then the resonant relationship of the circuit can be obtained:
admittance Y rr And Y pr From formulas (3) and (6), it can be derived that:
therefore, substituting equation (7) into equations (2) and (5) yields the expression of primary and secondary side resonance currents:
the transmission power expressions of the primary side and the secondary side of the system are obtained by the method:
therefore, when the resonance relation (6) is satisfied, the primary resonance current I can be obtained from the formula (8) 1 With secondary resonance voltage V r 90 DEG phase difference from the primary resonance voltage V p Is irrelevant; secondary side resonant current I 2 Then with the primary resonance voltage V p 90 deg. out of phase with the secondary resonance voltage V r Irrespective of the fact that the first and second parts are. Further, as can be seen from the formula (9)For given circuit parameters and direct current input voltage of the system, the power of the system depends on the output voltage of the primary and secondary side converters and the relative phase angle theta thereof, and the power transmission direction of the system only depends on the relative phase anglePhase angle θ. P when θ∈ (0, pi) p >0，P r <0, the lagging relative phase angle enables energy to be transmitted from the primary side to the secondary side, and the system transmits power in the forward direction; when θ∈ (-pi, 0), P p <0，P r >0, the leading relative phase angle enables energy transfer from the secondary side to the primary side, and the system reverses the transfer power. For any given voltage, when theta is + -pi/2, the reactive power is zero, the active power reaches a maximum value, and the system achieves maximum power transmission. FIG. 5 shows the transmission power P of the primary and secondary sides of the system p 、P r And a phase relation diagram of the relative phase angle theta.
In general, the number of the devices used in the system,delta epsilon (-2 pi, 2 pi), beta epsilon (-2 pi, 2 pi), phase shift angle of relative phase angle theta in different condition range of adjustable delay phase angles delta and beta>The relationship between these is shown in Table 1.
TABLE 1 phase shift angleRelationships between
From Table 1, the general expression between phase shift angles can be obtained:
thus, as can be seen from equation (10), by adjusting the phase shift angleAnd delta may control the relative phase angle theta of the converter output voltage to achieve a desired power flow.
In practice, however, due to the unavoidable shifting or misalignment of the coupling platesThe system may not reach full resonance, which may result in a change in the phasor relationship of the voltage and current of the circuit components. Fig. 6 is a graph showing current and voltage phasor relationships between circuit components with coupling plates fully aligned and misaligned. As shown in formula (2), I 2 From I 2p And I 2r Two components of the representation, each consisting of V p And Vr through admittance Y pr And Y rr And (3) generating. According to equation (7), if the system resonates, Y rr Is 0, Y pr Is 90 deg.. Thus, I 2r Zero, I 2p Perpendicular to V p As shown in fig. 6 (a). In particular, when V r Hysteresis V p At 90 DEG phase difference, V p And I 1 In phase, I 2 Advanced V p 90 deg.. In contrast, the current and voltage phasors for the circuit assembly when the plates are displaced are shown in fig. 6 (b). At this time, Y rr Is not zero, and introduces a current I generated by Vr 2r 。I 2 Is I 2p And I 2r Vector sum of (V), then V p And I 2 The phase difference between them being not 90 DEG, V p And I 1 Out of phase, the relation of equation (8) is not satisfied. In this case, the relation of the expression (9) is not satisfied, and there is a certain deviation between the transmission power and the phase angle shown in fig. 5. Therefore, the system is inaccurate in adjusting the magnitude and direction of power through the relative phase difference θ of the primary and secondary side converter output voltages in the event of a mismatch.
For example, FIG. 7 shows admittance Y when the coupling plates are misaligned and the coupling capacitance is changed in magnitude rr Amplitude magnitude and Y of (2) pr Phase angle of (f) and system resonant frequency f c Is a schematic diagram of the relationship of (a). By the above analysis, when Y rr Is zero in amplitude, Y pr When the phase angle of (2) is 90 DEG, the system is in resonance state and I 2r Zero and a fundamental resonant frequency f o Kept at 1MHz. While coupling capacitor C s From 0.8C s Change to 1.2C s At time f c Along with C s Is reduced and the system always deviates from f under detuning conditions o And (3) operating. At an equivalent coupling capacitance of 0.8C s At resonance frequency f c The change is 1.01MHz, and the equivalent coupling capacitance is 1.2C s Time resonance frequency f c The variation was 0.99MHz. Therefore, in order to restore the resonance state from the undesired detuned state, the driving frequency f s Should track in real time to a resonant frequency f corresponding to the coupling misalignment c . Thus V p And I 2 The phase difference between the two phases is 90 degrees, and the system can adjust the expected power magnitude and direction through the preset phase shift angle.
According to the above analysis, prior to bi-directional power flow regulation of the system, the system is in a non-resonant state due to possible misalignment or misalignment of the coupling plates, such that the phase relationship between the voltage and current between the circuit components changes. But the system can restore the phase relation between the circuits by adopting a method of tracking the resonant frequency by the driving frequency to restore the system to the resonant state. Specifically, when two pairs of bridge arms of the primary and secondary side converters are alternately conducted 180 DEG, V is caused r Hysteresis V p Phase difference of 90 DEGIs the case for (a). When the system is detuned, V p And I 1 Is not 0 DEG, V p And I 2 Also, the phase difference of (2) is not 90 DEG, and when the system resonates, V p And I 1 Zero phase difference, I 2 Advanced V p 90 deg.. Therefore, the primary resonance current and the voltage phase can be detected and compared directly through the primary controller, and then the working frequency of the BCPT system is adjusted according to the resonance frequency, so that the BCPT system reaches an integral resonance state before power flow adjustment.
Therefore, a simplified control block diagram of the frequency tuning and power flow regulation of a BCPT system is shown in fig. 8, where the primary side controller is responsible for the frequency tuning and the secondary side controller is used for bi-directional power flow regulation of the system.
Therefore, the embodiment of the invention provides a control method for frequency tuning and power flow decoupling of a BCPT system, a flow chart of which is shown in fig. 9, comprising the following steps:
s1, at the initial time, toDelta = 90 °, switching drive frequency f s The BCPT system is operated, and the system transmits power in the forward direction, < >>Respectively representing internal phase shift angles of the primary side converter and the secondary side converter, wherein delta represents an adjustable delay phase shift angle of the primary side converter;
s2, frequency tuning/tuning control: adjusting the switching drive frequency of the BCPT system to enable the primary side resonant current i 1 And the output voltage v of the primary side converter p The phase difference between them is 0;
s3, bidirectional power flow adjustment: regulation ofAnd delta, so that the power magnitude and direction of the BCPT system is the magnitude and direction of the expected power of the system.
The step S2 specifically comprises the steps of:
s21, detecting primary side resonance current i 1 And primary resonance voltage v p Obtaining i 1 And v p A phase difference between them;
s22, judging i 1 And v p If the phase difference is 0, a new switching driving frequency is generated to act on the BCPT system according to the phase difference if the phase difference is not 0, and if the phase difference is 0, the step S3 is performed.
The step S3 specifically comprises the steps of:
s31, collecting secondary side direct current I o And secondary side DC voltage V o Calculating power P of BCPT system o ＝I o *V o ；
S32, calculating P o And system expected power P e A difference between them;
s33, judging whether the power difference is 0, if so, keeping the current system parameters to operate, and if not, calculating a relative phase angle according to the power difference and entering the next step;
s34, adjusting according to the calculated relative phase angleAnd delta, leading the primary side resonance voltage v p And secondary resonance voltage v r The relative phase difference between them is such that the desired power P of the system is met e 。
The frequency tuning control for system detuning is run first. The bidirectional power flow adjustment is to adjust the phase shift angle after the secondary side controller receives the signal that the system reaches resonance and is sent by the primary side controller, so as to reach the expected power size and direction of the system.
After the frequency tuning control program is started, the switch driving frequency f of the system is given by using a set of default values s Internal phase angleAnd->Delay phase angle delta and desired power P e . Wherein->Delta=90°, namely, two pairs of bridge arms of the primary and secondary side converters are alternately conducted by 180 ° and the output voltage of the secondary side full-bridge converter lags behind the output voltage of the primary side full-bridge converter by 90 °.
The first stage is frequency tuning of the system. The new resonant frequency f is generated due to coupling mismatch caused by coupling plate offset/misalignment which may occur in the system c Therefore, the system must first perform tuning control on the circuit. First by detecting the resonant current i of the primary circuit 1 And resonance voltage v p Comparing the phase differences, generating an error signal to the primary side controller when the phase difference is not 0, and sequentially generating a new driving frequency by the primary side controller until f s ＝f c Thereby v is arranged as p And i 1 Achieve the same phase, i 2 Leading v p 90 deg.. At this point, the proposed system is in resonance. After the system reaches resonance, f s For the switching frequency of the system, the system is then ready for bi-directional power flow regulation.
The second stage is bi-directional power flow regulation of the system. The secondary side control circuit samples the direct current I o With DC voltage V o Obtaining real-time power P o The received actual power is compared with a preset reference power and the correction signal is used to adjust the phase angle control signal of each leg branch of the converter to change the voltage magnitude and the relative phase angle θ of the system until the desired power magnitude and direction of the system is reached.
In particular, once the system detects secondary DC I due to coupling plate offset during power flow regulation o The controller will immediately terminate the system power flow regulation process and restart the entire control process (sudden rise/dip, i.e., an increase or decrease in current value that exceeds a set threshold).
By way of the description of the frequency tuning and power flow decoupling control flow algorithm described above, fig. 10 depicts a simplified functional control block diagram, fig. 10 (a) is a frequency tuning control block diagram, and fig. 10 (b) is a bi-directional power flow control block diagram. The primary side control circuit mainly realizes the frequency tuning control of the system, so that the system is regulated to a resonance state; the secondary side control circuit implements bi-directional power flow regulation of the system.
Specifically, the primary side controller and the secondary side controller are used for starting at the initial momentDelta = 90 °, switching drive frequency f s The BCPT system is operated, and the system transmits power in the forward direction, < >>The internal phase shift angles of the primary and secondary converters are represented respectively, and delta represents the adjustable delay phase shift angle of the primary converter.
The primary side controller and the secondary side controller also adjust the switching drive frequency of the BCPT system so that the primary side resonance current i 1 And the output voltage v of the primary side converter p The phase difference between them is 0. The method specifically comprises the following steps:
the primary side controller detects primary side resonant current i 1 And primary resonance voltage v p Obtaining i 1 And v p A phase difference between them;
the primary side controller judges i 1 And v p If the phase difference is 0, generating a new switching driving frequency according to the phase difference to serve as a primary side converter, and sending the new switching driving frequency to a secondary side controller; if the tuning is 0, sending a message that tuning is completed to the secondary side controller;
the secondary side controller works with the new switch driving frequency if receiving the new switch driving frequency; and if the message that the tuning is completed is received, the operation is performed at the original switch driving frequency.
The secondary side controller also adjustsAnd delta, so that the power magnitude and direction of the BCPT system is the magnitude and direction of the expected power of the system. The method specifically comprises the following steps:
the secondary side controller collects secondary side direct current I o And secondary side DC voltage V o Calculating power P of BCPT system o ＝I o *V o ；
Secondary side controller calculates P o And system expected power P e A difference between them;
the secondary side controller judges whether the power difference is 0, if so, the current system parameters are kept to run, if not, the relative phase angle is calculated according to the power difference, and the relative phase angle is adjustedAnd delta, leading the primary side resonance voltage v p And secondary resonance voltage v r The relative phase difference between them is such that the desired power P of the system is met e 。
Secondary side controller in regulatingIn the delta process, the secondary side direct current I is detected in real time o If the secondary DC current I is detected o Sudden rise or fall, the regulation is stopped +.>And delta.
As shown in fig. 10 (a), the phase detection is implemented by a comparator and an exclusive-or logic operator (XOR). V (V) XOR Representing the output voltage after system phase detection, V L Represents V XOR The output voltage is filtered by a Low Pass Filter (LPF). A typical waveform for implementing the frequency tuning operation is shown in fig. 11. FIG. 11 (a) shows a waveform diagram of the system in a fully resonant state when v p And i 1 V is zero in phase difference of XOR Is 0, V L And also 0. In this case, the frequency generated by the controller is stable and fixed, at which point the system reaches a fully resonant state. FIG. 11 (b) shows V XOR Off-resonance system with 30% duty cycle, at which time v p And i 1 The phase difference between them is 54 °, in this case V L Greater than 0, the primary side controller captures v p Immediately after the rising edge of i) 1 And at the capture of v p Stopping judgment after the falling edge of (2): when i 1 V when changing from high level to low level p Hysteresis of i 1 The method comprises the steps of carrying out a first treatment on the surface of the Conversely, when i 1 When the voltage is changed from low level to high level, then v p Leading ahead of i 1 . Thus, the driving frequency of the system can be increased or decreased by judgment until the system reaches resonance and V L Is 0.
When the system is completely resonant, it can be seen from equation (9) and FIG. 5 that the primary and secondary side converters output voltage v for any power magnitude and direction p And v r The relative phase angle θ therebetween is varied, and as can be seen from equation (10) and Table 1, whenAt this time, θ is composed of only δ and +.>And determining the relative phase angle theta of the system, and changing the magnitude and the direction of the system power only by adjusting the bridge arm of the secondary side converter.
Thus, the secondary side controller will measure the power P according to equation (9) r And expect fromPower P e After comparison, the error signal is passed to an independent Proportional Integral (PI) control block to generate a relative phase angle θ, which in turn adjusts the phase angle control signal of the bridge arm legs of the converter And delta, to obtain the magnitude and direction of the desired power of the system.
In order to verify the feasibility of the BCPT system with frequency tuning and bidirectional power flow control provided by the embodiment of the invention, a 100W experimental device is built. The system includes primary and secondary full bridge converters (reversible rectifiers) controlled by two microcontrollers. The controller core has been fully HDL encoded and implemented on a Cyclone II FPGA. The full bridge converter implemented with GaN power modules can operate at MHz.
The frequency tuning circuit samples the phase of the primary resonant current and voltage through a current transformer (CU 8965-AL), a differential operational amplifier (AD 8058) and a high-speed comparator (TL 3016). The output voltage for primary side drive signal frequency algorithm adjustment is then generated by an exclusive-or operator (SN 5486), and finally the drive frequency of the switching tube is adjusted in the primary side controller to achieve system resonance.
The coupling capacitor structure adopts symmetrical design, wherein the size of the coupling electrode plate is 300×300mm 2 The plate distance d is 10mm, and two coupling capacitors C are formed s1 And C s2 . FIG. 12 shows the system resonant frequency f c And coupling capacitor C s1 、C s2 A graph of the value as a function of coupling plate spacing d and coupling plate offset b, where (a) of fig. 12 represents the coupling capacitance profile as the plate spacing changes, and (b) of fig. 12 represents the coupling capacitance profile as the plates are laterally offset. It can be seen that when the distance between the coupling polar plates is reduced, the coupling capacitance of the polar plates is increased continuously, and the resonant frequency of the system is reduced; when the coupling polar plate is deviated, the coupling capacitance of the polar plate is reduced, and the resonance frequency is increased. The circuit parameters of the experimental prototype were designed symmetrically from primary side to secondary side and summarized in table 2. To minimize the volume and size of the inductor, the capacitor C is compensated 1 And C 2 Is designed toFor 150pF, the parallel resonant capacitor uses a high voltage multilayer Surface Mount Device (SMD) ceramic capacitor. Compensating inductance L 1 And L 2 Is made of litz wire wound on a PVC pipe, the size of which is obtained according to the resonance relationship in formula (6) at a resonance frequency of 1 MHz.
Table 2 circuit parameters of BCPT system
The experimental results in fig. 13 show experimental waveforms of frequency tuning and power flow control of the coupling plate of the system with horizontal offset, when the two pairs of plates are offset laterally by about 150mm, with a coupling plate capacitance of 52pF. As can be seen from fig. 13, the initial frequency of the system is 1MHz, the primary and secondary converters operate at this frequency, the two pairs of legs of the primary and secondary converters are alternately turned on at 180 ° while the secondary side delays the primary side by 90 ° phase angle, at which time the secondary side resonant voltage output lags the primary side output voltage by 90 °, and the system will first forward transmit power. At t o Instantaneously, the primary side controller starts to detect the primary side resonance voltage v p And current i 1 And the phase difference is obtained, and then the driving signal frequency is regulated through a control algorithm, so that the driving frequency tracks and matches the resonant frequency of the system, and the system reaches resonance. In addition, FIG. 13 shows an enlarged view of the increase in switching frequency from 1MHz to 1.04MHz and its steady state during frequency tuning control, it can be seen that t o Before the moment, there is a slight difference between the operating frequency and the resonance frequency due to the system detuning, in which case i 1 Lead v p ，v p And i 2 Not 90 deg. out of phase (i in fig. 13 2 Reverse). After tuning the system frequency, from t o ～t 1 As can be seen from the steady-state enlarged view of the time period, v p And i 1 In phase, v p And i 2 The phases differ by 90 deg.. Then at t 1 At the moment, the system generates a phase shift angle according to the expected power magnitude and directionAnd delta, then to control system power by varying theta. When the system expects a forward transmission power of 40W, it can be seen from an enlarged view of the steady state after power regulation, when δ=150°, respectively>θ＝90°。
The experimental results in fig. 14 show that the frequency tuning and power adjustment response is performed under the condition that the distance between the coupling plates of the system is changed, and when the distance between the two pairs of plates is about 6mm, the capacitance of the coupling plates is 80pF. In agreement with the operating principle of fig. 13, it can be seen from fig. 14 that, first, the primary and secondary side converters of the system operate at an initial frequency of 1MHz, the secondary side converter delays the primary side by 90 ° phase angle, and the system first performs forward power transfer. At t o At the moment, the primary side controller starts to detect v p And i 1 The drive signal frequency is adjusted so that the switching tube drive frequency is reduced from 1MHz to 0.96MHz to thereby resonate the system. An enlarged view of the steady state frequency tuning control is shown in fig. 14, where it can be seen that t o Before the moment, the system is detuned due to the change of the distance between the coupling polar plates, i 1 Lead v p ，v p And i 2 Not 90 deg. out of phase (i in figure 14 2 Reverse). And from t o ～t 1 As can be seen from the steady-state enlarged view of the time period, v after frequency tracking tuning p And i 1 In phase, v p And i 2 The phases differ by 90 deg., and the system reaches a resonant state. At t 1 At this point in time, the system is performing power flow regulation, at which point the system expects to achieve a reverse transmission power of 28W, and from a steady-state, magnified view, the phase shift angle of the system is delta = 300,θ＝-90°。
in summary, the embodiment of the invention provides a frequency tuning and bidirectional power flow decoupling control system and method based on the BCPT system adopting phase-shifting bidirectional power flow adjustment, aiming at the problem that after the coupling capacitance changes to cause system detuning due to misalignment of the coupling polar plates and the vector relation between voltage and current among circuit components changes, the system power flow can be reduced in system charging power level or power deviation is generated by adjusting the phase or amplitude of the resonant voltage of the primary and secondary side converters, and the basic characteristics of the double-sided LC resonant network BCPT system are surrounded. Simulation and experimental results verify the implementation of frequency tuning control and bi-directional power flow regulation. Experimental results show that the tuning control method can be effectively applied to bidirectional power flow adjustment of the system, and a more effective solution is provided for the problem of system detuning caused by dislocation of the polar plates of the BCPT system.
The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above examples, and any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principle of the present invention should be made in the equivalent manner, and the embodiments are included in the protection scope of the present invention.
Claims (10)
- The frequency tuning and power flow decoupling control method of a BCPT system comprises a primary side and a secondary side, wherein the primary side comprises primary side direct-current voltage V which are sequentially connected d The secondary side comprises a secondary side coupling polar plate, a secondary side compensation network, a secondary side converter and a secondary side direct current voltage V which are sequentially connected o The control method is characterized by comprising the following steps:s1, at the initial time, toDelta = 90 °, switching drive frequency f s The BCPT system is operated, and the system transmits power in the forward direction, < >>Respectively representing internal phase shift angles of the primary side converter and the secondary side converter, wherein delta represents an adjustable delay phase shift angle of the primary side converter;s2, adjusting the switching driving frequency of the BCPT system to enable the primary side resonant current i to be 1 And the output voltage v of the primary side converter p The phase difference between them is 0;s3, adjustingAnd delta, so that the power magnitude and direction of the BCPT system is the magnitude and direction of the expected power of the system.
- 2. The method for controlling frequency tuning and power flow decoupling of BCPT system according to claim 1, wherein said step S2 comprises the steps of:s21, detecting primary side resonance current i 1 And primary resonance voltage v p Obtaining i 1 And v p A phase difference between them;s22, judging i 1 And v p If the phase difference is 0, a new switching driving frequency is generated to act on the BCPT system according to the phase difference if the phase difference is not 0, and if the phase difference is 0, the step S3 is performed.
- 3. The method for controlling frequency tuning and power flow decoupling of BCPT system according to claim 2, wherein said step S3 comprises the steps of:s31, collecting secondary side direct current I o And secondary side DC voltage V o Calculating power P of BCPT system o ＝I o *V o ；S32, calculating P o And system expected power P e A difference between them;s33, judging whether the power difference is 0, if so, keeping the current system parameters to operate, and if not, calculating a relative phase angle according to the power difference and entering the next step;s34, adjusting according to the calculated relative phase angle And delta, leading the primary side resonance voltage v p And secondary resonance voltage v r The relative phase difference between them is such that the desired power P of the system is met e 。
- 4. The method for controlling frequency tuning and power flow decoupling of BCPT system as claimed in claim 3, wherein: in said step S3, in the adjustingAnd delta, if the secondary side direct current I is detected o Sudden rise or fall, the regulation is stoppedAnd δ and returns to step S1.
- 5. The method for controlling frequency tuning and power flow decoupling of BCPT system as claimed in claim 4, wherein in said step S33, the relative phase angle is calculated based on the following principle:the power transfer expressions of the primary side and the secondary side are:wherein P is p 、P r Representing the transmission power, ω, of the primary side and the secondary side, respectively c Representing the resonant angular frequency of the system as well as the operating angular frequency, C 1 Representing primary resonance compensation capacitance, C in primary LC-type compensation network 2 Representing secondary side resonance compensation capacitance, C in a secondary side LC type compensation network s Representing the equivalent coupling capacitance between the primary side coupling plate and the secondary side coupling plate, V p 、V r Representing the effective values of the primary and secondary resonance voltages, respectively, θ representing the relative phase angle, i.e., primary resonance voltage v p And secondary resonance voltage v r A relative phase difference between them; p when θ∈ (0, pi) p >0，P r <0, the retarded relative phase angle enables energy transfer from primary side to secondary side, system forward power transfer; when θ∈ (-pi, 0), P p <0，P r >0, the leading relative phase angle enables energy transfer from the secondary side to the primary side, the system reversing power transfer;in the step S34, the adjustment is based on the following relationAnd delta, such that the primary resonance voltage v p And secondary resonance voltage v r The relative phase difference therebetween satisfies the calculated relative phase angle:wherein β represents an adjustable delay phase shift angle of the secondary side converter.
- A BCPT system frequency tuning and power flow decoupling control system for use in a BCPT system as in claim 1, wherein: the primary side controller is connected with the primary side converter, and the secondary side controller is connected with the secondary side converter;the primary side controller and the secondary side controller are used for at the initial momentDelta = 90 °, switching drive frequency f s The BCPT system is operated, and the system transmits power in the forward direction, < >>Respectively representing internal phase shift angles of the primary side converter and the secondary side converter, wherein delta represents an adjustable delay phase shift angle of the primary side converter;The primary side controller and the secondary side controller are also used for adjusting the switching driving frequency of the BCPT system so as to lead the primary side resonant current i to be 1 And the output voltage v of the primary side converter p The phase difference between them is 0;the secondary side controller is also used for adjustingAnd delta, so that the power magnitude and direction of the BCPT system is the magnitude and direction of the expected power of the system.
- 7. The BCPT system frequency tuning and power flow decoupling control system of claim 6, wherein said primary side controller and said secondary side controller are further configured to adjust a BCPT system switching drive frequency such that primary side resonant current i 1 And the output voltage v of the primary side converter p The phase difference between the two is 0, specifically comprising:the primary side controller detects primary side resonance current i 1 And primary resonance voltage v p Obtaining i 1 And v p A phase difference between them;the primary side controller judges i 1 And v p If the phase difference is 0, generating a new switching driving frequency to act on the primary side converter according to the phase difference, and transmitting the new switching driving frequency to the secondary side controller; if the tuning is 0, sending a message that tuning is completed to the secondary side controller;the secondary side controller works with the new switch driving frequency if receiving the new switch driving frequency; and if the message that the tuning is completed is received, the operation is performed at the original switch driving frequency.
- 8. The BCPT system frequency tuning and power flow decoupling control system of claim 7, whereinThe secondary side controller is also used for adjustingAnd delta, enabling the power magnitude and direction of the BCPT system to be the magnitude and direction of the expected power of the system, and specifically comprising:the secondary side controller collects secondary side direct current I o And secondary side DC voltage V o Calculating power P of BCPT system o ＝I o *V o ；The secondary side controller calculates P o And system expected power P e A difference between them;the secondary side controller judges whether the power difference is 0, if so, the current system parameters are kept to run, if not, the relative phase angle is calculated according to the power difference, and the relative phase angle is adjustedAnd delta, leading the primary side resonance voltage v p And secondary resonance voltage v r The relative phase difference between them is such that the desired power P of the system is met e 。
- 9. The BCPT system frequency tuning and power flow decoupling control system of claim 8, wherein: the secondary side controller is adjustingIn the delta process, the secondary side direct current I is detected in real time o If the secondary DC current I is detected o Sudden rise or fall, the regulation is stopped +.>And delta.
- 10. The BCPT system frequency tuning and power flow decoupling control system of claim 9, wherein the secondary side controller calculates the relative phase angle based on:The power transfer expressions of the primary side and the secondary side are:wherein P is p 、P r Representing the transmission power, ω, of the primary side and the secondary side, respectively c Representing the resonant angular frequency of the system as well as the operating angular frequency, C 1 Representing primary resonance compensation capacitance, C in primary LC-type compensation network 2 Representing secondary side resonance compensation capacitance, C in a secondary side LC type compensation network s Representing the equivalent coupling capacitance between the primary side coupling plate and the secondary side coupling plate, V p 、V r Representing the effective values of the primary and secondary resonance voltages, respectively, θ representing the relative phase angle, i.e., primary resonance voltage v p And secondary resonance voltage v r A relative phase difference between them; p when θ∈ (0, pi) p >0，P r <0, the retarded relative phase angle enables energy transfer from primary side to secondary side, system forward power transfer; when θ∈ (-pi, 0), P p <0，P r >0, the leading relative phase angle enables energy transfer from the secondary side to the primary side, the system reversing power transfer;the secondary side controller adjusts based on the following relationshipAnd delta, such that the primary resonance voltage v p And secondary resonance voltage v r The relative phase difference therebetween satisfies the calculated relative phase angle:wherein β represents an adjustable delay phase shift angle of the secondary side converter.
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Citations (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102522900A (en) * | 2011-11-18 | 2012-06-27 | 南京航空航天大学 | Fixed-gain self-excited non-contact resonant converter and control method thereof |
| EP3145047A1 (en) * | 2014-05-14 | 2017-03-22 | WQC, Inc. | Wireless power transfer device |
| JP2017216816A (en) * | 2016-05-31 | 2017-12-07 | パナソニックＩｐマネジメント株式会社 | Non-contact power supply device, program, control method for non-contact power supply device, and non-contact power transmission system |
| CN107750412A (en) * | 2015-06-19 | 2018-03-02 | 高通股份有限公司 | The equipment, system and method for using reactive power to inject for active tuning charging system for motor-driven vehicle |
| CN107852197A (en) * | 2015-07-24 | 2018-03-27 | 高通股份有限公司 | The equipment, system and method for power output are adjusted for being controlled using synchronous rectifier |
| CN108521177A (en) * | 2018-06-08 | 2018-09-11 | 南京航空航天大学 | Controlled resonant converter regulating device and control method based on additional coupling inductance |
| CN108544935A (en) * | 2018-03-20 | 2018-09-18 | 清华大学 | A kind of bidirectional electric automobile wireless charging system transmission power control method |
| CN207994738U (en) * | 2018-02-07 | 2018-10-19 | 广州大学 | High power intelligent pressure-adjustable charging system based on resonance type wireless electric energy transmission technology |
| CN109462466A (en) * | 2018-11-19 | 2019-03-12 | 中国矿业大学 | A kind of single channel energy signal synchronous transmission system phase shifting control implementation method and the system |
| CN110293859A (en) * | 2019-07-29 | 2019-10-01 | 广东电网有限责任公司 | A kind of tour unmanned plane charges device for supplying and method online |
| CN111224471A (en) * | 2020-02-27 | 2020-06-02 | 西安理工大学 | Maximum efficiency tracking method for electric field coupling type underwater wireless electric energy transmission system |
| CN111525706A (en) * | 2020-05-11 | 2020-08-11 | 安洁无线科技（苏州）有限公司 | Frequency modulation type phase-locking synchronous rectification control circuit and frequency modulation type phase-locking method |
| CN111654116A (en) * | 2020-04-17 | 2020-09-11 | 中国矿业大学 | High-gain constant-voltage constant-current output electric field coupling wireless power transmission system |
| CN112260549A (en) * | 2020-10-23 | 2021-01-22 | 中国科学院电工研究所 | Method for reducing loss of primary side inverter of resonant wireless power transmission system |
| CN114172249A (en) * | 2022-01-10 | 2022-03-11 | 深圳威迈斯新能源股份有限公司 | Automobile wireless charging system and control method thereof |
| EP4030605A1 (en) * | 2021-01-19 | 2022-07-20 | Delta Electronics (Shanghai) Co., Ltd. | Conversion system and control method thereof |
| CN114784988A (en) * | 2022-05-24 | 2022-07-22 | 重庆大学 | EC-WPT system for bidirectional transmission of asymmetric signals and energy crosstalk inhibition method |
| CN115102304A (en) * | 2022-07-25 | 2022-09-23 | 重庆大学 | Bidirectional electric field coupling type wireless power transmission system and control method thereof |
| CN115864665A (en) * | 2022-10-31 | 2023-03-28 | 重庆大学 | Anti-coupling mechanism deviation EC-WPT system with constant current output characteristic |
| CN116207874A (en) * | 2022-12-12 | 2023-06-02 | 湘潭大学 | Bilateral decoupling self-adaptive tuning control strategy and implementation device for LCC/S compensation wireless power transmission system |
-
2023
- 2023-09-12 CN CN202311176311.9A patent/CN117040144B/en active Active
Patent Citations (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102522900A (en) * | 2011-11-18 | 2012-06-27 | 南京航空航天大学 | Fixed-gain self-excited non-contact resonant converter and control method thereof |
| EP3145047A1 (en) * | 2014-05-14 | 2017-03-22 | WQC, Inc. | Wireless power transfer device |
| CN107750412A (en) * | 2015-06-19 | 2018-03-02 | 高通股份有限公司 | The equipment, system and method for using reactive power to inject for active tuning charging system for motor-driven vehicle |
| CN107852197A (en) * | 2015-07-24 | 2018-03-27 | 高通股份有限公司 | The equipment, system and method for power output are adjusted for being controlled using synchronous rectifier |
| JP2017216816A (en) * | 2016-05-31 | 2017-12-07 | パナソニックＩｐマネジメント株式会社 | Non-contact power supply device, program, control method for non-contact power supply device, and non-contact power transmission system |
| CN207994738U (en) * | 2018-02-07 | 2018-10-19 | 广州大学 | High power intelligent pressure-adjustable charging system based on resonance type wireless electric energy transmission technology |
| CN108544935A (en) * | 2018-03-20 | 2018-09-18 | 清华大学 | A kind of bidirectional electric automobile wireless charging system transmission power control method |
| CN108521177A (en) * | 2018-06-08 | 2018-09-11 | 南京航空航天大学 | Controlled resonant converter regulating device and control method based on additional coupling inductance |
| CN109462466A (en) * | 2018-11-19 | 2019-03-12 | 中国矿业大学 | A kind of single channel energy signal synchronous transmission system phase shifting control implementation method and the system |
| CN110293859A (en) * | 2019-07-29 | 2019-10-01 | 广东电网有限责任公司 | A kind of tour unmanned plane charges device for supplying and method online |
| CN111224471A (en) * | 2020-02-27 | 2020-06-02 | 西安理工大学 | Maximum efficiency tracking method for electric field coupling type underwater wireless electric energy transmission system |
| CN111654116A (en) * | 2020-04-17 | 2020-09-11 | 中国矿业大学 | High-gain constant-voltage constant-current output electric field coupling wireless power transmission system |
| CN111525706A (en) * | 2020-05-11 | 2020-08-11 | 安洁无线科技（苏州）有限公司 | Frequency modulation type phase-locking synchronous rectification control circuit and frequency modulation type phase-locking method |
| CN112260549A (en) * | 2020-10-23 | 2021-01-22 | 中国科学院电工研究所 | Method for reducing loss of primary side inverter of resonant wireless power transmission system |
| EP4030605A1 (en) * | 2021-01-19 | 2022-07-20 | Delta Electronics (Shanghai) Co., Ltd. | Conversion system and control method thereof |
| CN114172249A (en) * | 2022-01-10 | 2022-03-11 | 深圳威迈斯新能源股份有限公司 | Automobile wireless charging system and control method thereof |
| CN114784988A (en) * | 2022-05-24 | 2022-07-22 | 重庆大学 | EC-WPT system for bidirectional transmission of asymmetric signals and energy crosstalk inhibition method |
| CN115102304A (en) * | 2022-07-25 | 2022-09-23 | 重庆大学 | Bidirectional electric field coupling type wireless power transmission system and control method thereof |
| CN115864665A (en) * | 2022-10-31 | 2023-03-28 | 重庆大学 | Anti-coupling mechanism deviation EC-WPT system with constant current output characteristic |
| CN116207874A (en) * | 2022-12-12 | 2023-06-02 | 湘潭大学 | Bilateral decoupling self-adaptive tuning control strategy and implementation device for LCC/S compensation wireless power transmission system |
Non-Patent Citations (5)
| Title |
|---|
| HAO TONG;HENG NIAN;BIN HU;MENG LI;HONGYU ZHANG;QINGSHI LIU: "High-Frequency Resonance Analysis Between DFIG Based Wind Farm with Direct Power Control and VSC-HVDC", 《2021 24TH INTERNATIONAL CONFERENCE ON ELECTRICAL MACHINES AND SYSTEMS (ICEMS)》, 31 December 2021 (2021-12-31) * |
| 刘晓胜;顾轩溥;姚友素;徐殿国;: "基于电容调制的无线电能传输系统信号电能同步传输", 电力自动化设备, no. 03, 9 March 2018 (2018-03-09) * |
| 孙长江;蔡旭;张建文;施刚;: "电压自均衡直接耦合式模块化多电平直流变压器", 中国电机工程学报, no. 21, 19 October 2018 (2018-10-19) * |
| 贾金亮;闫晓强;: "磁耦合谐振式无线电能传输特性研究动态", 电工技术学报, no. 20, 25 October 2020 (2020-10-25) * |
| 高键鑫;吴旭升;高嵬;胡风革;李广义;: "基于LCL谐振变换器的电磁感应式非接触电能传输系统动态调压控制方法", 电工技术学报, no. 18, 6 December 2017 (2017-12-06) * |
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