Method, system and electronic device for determining modulation strategy of wireless power transfer system

Abstract

The application discloses a wireless power transmission system modulation strategy determination method, system and electronic equipment, and relates to the technical field of power system optimization control. The method comprises the following steps: calculating a double-phase shift outer phase shift angle value based on system parameters and a double-phase shift primary side inner phase shift angle value; calculating a double-phase shift output power based on a primary side direct current input voltage, an angular frequency, the double-phase shift primary side inner phase shift angle value, a self-inductance of a transmitting coil, a coupling coefficient, a secondary side direct current output voltage, the double-phase shift outer phase shift angle value and a double-phase shift secondary side inner phase shift angle value; calculating an extended phase shift outer phase shift angle value based on system parameters and an extended phase shift primary side inner phase shift angle value; calculating an extended phase shift output power in the same way; and determining a target modulation strategy based on the double-phase shift output power and the extended phase shift output power. The application realizes power tracking, impedance matching and ZVS of a switching tube in a full working condition and a wide voltage range by using two control degrees of freedom, and has lower switching loss.

Description

Technical Field

[0001] This invention relates to the field of power system optimization control technology, and in particular to a method, system, and electronic device for determining modulation strategies in a wireless power transmission system. Background Technology

[0002] Inductive Power Transmission (IPT) systems have garnered significant attention over the past few decades due to their flexibility and reliability. As a convenient and safe charging method that transfers energy without physical connections, it effectively avoids electrical sparks during charging and exhibits strong adaptability to harsh conditions such as rain and snow. Furthermore, IPT systems offer electrical isolation and a better smart user experience. In recent years, IPT has been widely applied in consumer electronics, medical devices, underwater electronic equipment, and electric vehicles. In practical applications, such as electric vehicles, the battery voltage typically increases with charging, requiring IPT systems to maintain high efficiency under varying output voltage conditions. However, IPT systems typically consist of inverters, compensation networks, magnetic couplers, and rectifiers, all operating in high-frequency environments. This complex structure leads to various unavoidable losses in wireless power transmission systems. In addition, wireless power transmission systems also suffer from impedance mismatch and increased reactive power under light load conditions, further contributing to low system transmission efficiency.

[0003] Patent CN115459318A proposes a method for determining the modulation strategy of a bidirectional wireless charging control wireless power transmission system. This scheme has two control degrees of freedom, but only considers the inner phase shift angle of the primary and secondary bridge arms, ignoring the outer phase shift angle between the primary and secondary arms. Under light load conditions, this can lead to excessive reactive power, resulting in significant system losses. Patent CN110758132B proposes a method for determining the modulation strategy of a variable-angle phase-shift control wireless power transmission system for optimizing the efficiency of wireless charging for electric vehicles. This scheme requires three control degrees of freedom, making the control logic more complex. Furthermore, it involves calculating the zero-voltage switching of the switching transistors. The accuracy is poor because the influence of higher harmonics is not considered when using the switch (ZVS) condition. Patent CN109823206B proposes a method for determining the modulation strategy of a wireless power transmission system for wireless charging control based on bilateral phase shifting and frequency modulation. This scheme adopts frequency modulation to reduce reactive power, but the effect of frequency modulation is limited. In particular, under light load conditions, there is still a large amount of reactive power when using frequency modulation. In addition, it requires additional switching transistors, which increases the system size and cost. Summary of the Invention

[0004] The purpose of this invention is to provide a method, system, and electronic device for determining the modulation strategy of a wireless power transmission system. It utilizes two degrees of control freedom to achieve power tracking, impedance matching, and ZVS of the switching transistors across all operating conditions and a wide voltage range, while also exhibiting lower switching losses.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] A method for determining a modulation strategy in a wireless power transmission system, the method comprising:

[0007] The system parameters and the internal phase shift angle of the primary side of the dual-phase-shifting system are determined. The system parameters include: primary-side DC input voltage, secondary-side DC output voltage, angular frequency, minimum current of the switching transistor when it is turned on at zero voltage, coupling coefficient, and self-inductance of the transmitting coil. The target system is a wireless power transmission system with SS compensation topology. The coupling coefficient is the coupling coefficient between the transmitting coil and the receiving coil. The internal phase shift angle of the primary side of the dual-phase-shifting system is the internal phase shift angle of the primary side under the dual-phase-shifting modulation strategy.

[0008] Based on the system parameters, the primary phase shift angle of the dual-phase shift and the primary phase shift angle of the extended phase shift, the relationship of the primary phase shift angle is determined; the relationship of the primary phase shift angle is the relationship between the primary phase shift angle of the dual-phase shift and the primary phase shift angle of the extended phase shift, the primary phase shift angle of the dual-phase shift is the primary phase shift angle under the dual-phase shift modulation strategy, and the primary phase shift angle of the extended phase shift is the primary phase shift angle under the extended phase shift modulation strategy.

[0009] Based on the primary phase shift angle relationship and the primary phase shift angle value of the dual-phase shift, the primary phase shift angle value of the extended phase shift is determined.

[0010] For the dual-phase-shift modulation strategy:

[0011] Based on the system parameters and the inner phase shift angle value of the primary phase shifter, the outer phase shift angle value of the dual phase shifter is calculated;

[0012] The dual-phase output power is calculated based on the primary-side DC input voltage, the angular frequency, the inner phase shift angle of the primary side of the dual-phase shift, the self-inductance of the transmitting coil, the coupling coefficient, the secondary-side DC output voltage, the outer phase shift angle of the dual-phase shift, and the inner phase shift angle of the secondary side of the dual-phase shift; the inner phase shift angle of the secondary side of the dual-phase shift is equal to the inner phase shift angle of the primary side of the dual-phase shift.

[0013] For extended phase-shift modulation strategies:

[0014] Based on the system parameters and the extended phase shift angle value on the primary side, calculate the extended phase shift angle value.

[0015] The extended phase-shift output power is calculated based on the primary side DC input voltage, the angular frequency, the extended phase-shift primary side inner phase-shift angle value, the self-inductance of the transmitting coil, the coupling coefficient, the secondary side DC output voltage, the extended phase-shift outer phase-shift angle value, and the extended phase-shift secondary side inner phase-shift angle value; the extended phase-shift secondary side inner phase-shift angle value is 0.5.

[0016] The target modulation strategy of the target system is determined based on the dual-phase-shift output power and the extended phase-shift output power.

[0017] Optionally, the process of determining the minimum current specifically includes:

[0018] Obtain the dead time and junction capacitance of the switching transistor;

[0019] The minimum current is determined based on the primary-side DC input voltage, the dead time, and the junction capacitance.

[0020] Optionally, based on the system parameters, the primary side inner phase shift angle of the dual-phase shift and the primary side inner phase shift angle of the extended phase shift, the relationship of the primary side inner phase shift angle is determined, specifically including:

[0021] A dual-phase shift current function is constructed based on the system parameters and the internal phase shift angle of the primary side of the dual-phase shift.

[0022] The extended phase-shifting current function is constructed based on the system parameters and the extended phase-shifting primary side internal phase-shifting angle.

[0023] Based on the dual-phase-shifting current function and the extended phase-shifting current function, the relationship of the phase-shifting angle on the primary side is determined.

[0024] Optionally, the dual-phase output power is calculated based on the primary-side DC input voltage, the angular frequency, the inner phase shift angle of the primary side of the dual-phase shift, the self-inductance of the transmitting coil, the coupling coefficient, the secondary-side DC output voltage, the outer phase shift angle of the dual-phase shift, and the inner phase shift angle of the secondary side of the dual-phase shift, specifically including:

[0025] Calculate the dual-phase-shifted input side voltage based on the primary-side DC input voltage, the angular frequency, and the internal phase-shifting angle value of the dual-phase-shifted primary side.

[0026] The dual-phase output voltage is calculated based on the secondary side DC output voltage, the angular frequency, the inner phase shift angle of the dual-phase secondary side, and the outer phase shift angle of the dual-phase secondary side.

[0027] The dual-phase output power is calculated based on the coupling coefficient, the angular frequency, the self-inductance of the transmitting coil, the dual-phase input voltage, the dual-phase output voltage, and the dual-phase delay phase angle.

[0028] Optionally, the dual-phase-shifted output voltage is calculated based on the secondary-side DC output voltage, the angular frequency, the inner phase-shift angle value of the dual-phase-shifted secondary side, and the outer phase-shift angle value of the dual-phase-shifted secondary side, specifically including:

[0029] The dual-phase shift delay phase angle is calculated based on the external phase shift angle value and the internal phase shift angle value of the primary side of the dual-phase shift; the dual-phase shift delay phase angle value is the phase angle value of the delay between the dual-phase shift input voltage and the dual-phase shift output voltage under the dual-phase shift modulation strategy.

[0030] The dual-phase output voltage is calculated based on the secondary-side DC output voltage, the angular frequency, the internal phase-shift angle of the dual-phase-shift secondary side, and the dual-phase-shift delay angle.

[0031] Optionally, the extended phase-shift output power is calculated based on the primary-side DC input voltage, the angular frequency, the extended phase-shift primary-side inner phase-shift angle value, the self-inductance of the transmitting coil, the coupling coefficient, the secondary-side DC output voltage, the extended phase-shift outer phase-shift angle value, and the extended phase-shift secondary-side inner phase-shift angle value, specifically including:

[0032] Calculate the extended phase-shift input side voltage based on the primary side DC input voltage, the angular frequency, and the extended phase-shift primary side internal phase-shift angle value;

[0033] Based on the secondary side DC output voltage, the angular frequency, the extended phase-shifting secondary side inner phase-shifting angle value, and the extended phase-shifting outer phase-shifting angle value, calculate the extended phase-shifting output side voltage;

[0034] The extended phase-shift output power is calculated based on the coupling coefficient, the angular frequency, the self-inductance of the transmitting coil, the extended phase-shift input voltage, the extended phase-shift output voltage, and the extended phase-shift delay phase angle.

[0035] Optionally, the extended phase-shifted output voltage is calculated based on the secondary-side DC output voltage, the angular frequency, the extended phase-shifted secondary-side inner phase-shift angle value, and the extended phase-shifted outer phase-shift angle value, specifically including:

[0036] The extended phase shift delay phase angle is calculated based on the extended phase shift outer phase angle value and the extended phase shift primary side inner phase angle value; the extended phase shift delay phase angle value is the phase angle value of the delay between the extended phase shift input side voltage and the extended phase shift output side voltage under the extended phase shift modulation strategy.

[0037] The extended phase-shifted output voltage is calculated based on the secondary side DC output voltage, the angular frequency, the extended phase-shifted secondary side internal phase-shifting angle value, and the extended phase-shifting delay phase angle value.

[0038] Optionally, the target modulation strategy of the target system is determined based on the dual-phase-shift output power and the extended phase-shift output power, specifically including:

[0039] When the dual-phase-shift output power is greater than the extended phase-shift output power, the dual-phase-shift modulation strategy is determined as the target modulation strategy;

[0040] When the dual-phase-shift output power is less than the extended-phase-shift output power, the extended-phase-shift modulation strategy is determined as the target modulation strategy;

[0041] When the dual-phase-shift output power is equal to the extended-phase-shift output power, the dual-phase-shift modulation strategy or the extended-phase-shift modulation strategy is determined as the target modulation strategy.

[0042] A system for determining a modulation strategy for a wireless power transmission system, the system comprising:

[0043] The parameter determination module is used to determine the system parameters and the internal phase shift angle value of the primary side of the target system. The system parameters include: primary side DC input voltage, secondary side DC output voltage, angular frequency, minimum current of the switching transistor when it is turned on at zero voltage, coupling coefficient, and self-inductance of the transmitting coil. The target system is a wireless power transmission system with SS compensation topology, and the coupling coefficient is the coupling coefficient between the transmitting coil and the receiving coil. The internal phase shift angle value of the primary side of the dual-phase shift modulation strategy is the internal phase shift angle value of the primary side.

[0044] The relationship determination module is used to determine the relationship of the primary phase shift angle based on the system parameters, the primary phase shift angle of the dual-phase shifting modulator, and the primary phase shift angle of the extended-phase shifting modulator; the relationship of the primary phase shift angle is the relationship between the primary phase shift angle of the dual-phase shifting modulator and the primary phase shift angle of the extended-phase shifting modulator, wherein the primary phase shift angle of the dual-phase shifting modulator is the primary phase shift angle under the dual-phase shifting modulator strategy, and the primary phase shift angle of the extended-phase shifting modulator is the primary phase shift angle under the extended-phase shifting modulator strategy;

[0045] The extended phase shifting primary side inner phase shift angle value determination module is used to determine the extended phase shifting primary side inner phase shift angle value based on the inner phase shift angle relationship of the primary side and the inner phase shift angle value of the dual phase shifting primary side;

[0046] The dual-phase-shift output power calculation module is used for:

[0047] Based on the system parameters and the inner phase shift angle value of the primary phase shifter, the outer phase shift angle value of the dual phase shifter is calculated;

[0048] The dual-phase output power is calculated based on the primary-side DC input voltage, the angular frequency, the inner phase shift angle of the primary side of the dual-phase shift, the self-inductance of the transmitting coil, the coupling coefficient, the secondary-side DC output voltage, the outer phase shift angle of the dual-phase shift, and the inner phase shift angle of the secondary side of the dual-phase shift; the inner phase shift angle of the secondary side of the dual-phase shift is equal to the inner phase shift angle of the primary side of the dual-phase shift.

[0049] The extended phase-shift output power calculation module is used for:

[0050] Based on the system parameters and the extended phase shift angle value on the primary side, calculate the extended phase shift angle value.

[0051] The extended phase-shift output power is calculated based on the primary side DC input voltage, the angular frequency, the extended phase-shift primary side inner phase-shift angle value, the self-inductance of the transmitting coil, the coupling coefficient, the secondary side DC output voltage, the extended phase-shift outer phase-shift angle value, and the extended phase-shift secondary side inner phase-shift angle value; the extended phase-shift secondary side inner phase-shift angle value is 0.5.

[0052] The target modulation strategy determination module is used to determine the target modulation strategy of the target system based on the dual phase-shift output power and the extended phase-shift output power.

[0053] An electronic device, comprising:

[0054] One or more processors;

[0055] A storage device on which one or more programs are stored;

[0056] When the one or more programs are executed by the one or more processors, the one or more processors implement the method for determining the modulation strategy of the wireless power transmission system as described above.

[0057] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0058] This invention discloses a method, system, and electronic device for determining the modulation strategy of a wireless power transmission system. By utilizing two control degrees of freedom, namely the primary side internal phase shift angle value and the secondary side internal phase shift angle value, the modulation strategy of the wireless power transmission system is determined, achieving power tracking, impedance matching, and ZVS of the switching transistors under all operating conditions and a wide voltage range. Attached Figure Description

[0059] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0060] Figure 1 This is a schematic flowchart of the method for determining the modulation strategy of a wireless power transmission system provided in Embodiment 1 of the present invention;

[0061] Figure 2 A schematic diagram of a wireless power transmission system with SS compensation topology;

[0062] Figure 3 A schematic diagram of the equivalent circuit of a wireless power transmission system with SS compensation topology;

[0063] Figure 4 This is a schematic diagram of the system structure for determining the modulation strategy of a wireless power transmission system according to Embodiment 2 of the present invention. Detailed Implementation

[0064] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0065] The purpose of this invention is to provide a method, system, and electronic device for determining the modulation strategy of a wireless power transmission system, which aims to achieve power tracking, impedance matching, and ZVS of the switching transistors under all operating conditions and a wide voltage range using two degrees of control freedom, while having lower switching losses.

[0066] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0067] Example 1

[0068] Figure 1 This is a schematic flowchart illustrating the method for determining the modulation strategy of a wireless power transmission system according to Embodiment 1 of the present invention. Figure 1 As shown, the method for determining the modulation strategy of the wireless power transmission system in this embodiment includes:

[0069] Step 101: Determine the system parameters of the target system and the phase shift angle value of the primary side of the dual-phase shift system.

[0070] The system parameters include: primary side DC input voltage, secondary side DC output voltage, angular frequency, minimum current of the switching transistor when it is turned on at zero voltage, coupling coefficient, and self-inductance of the transmitting coil; the target system is a wireless power transmission system with SS compensation topology, the coupling coefficient is the coupling coefficient between the transmitting coil and the receiving coil; the primary side internal phase shift angle value of the dual phase shift modulation strategy is the primary side internal phase shift angle value.

[0071] Specifically, such as Figure 2 As shown, for a wireless power transmission system with SS compensation topology, when power flows from left to right: S1, S2, S3, and S4 are MOSFETs (i.e., primary-side switches) of the primary-side active bridge, acting as high-frequency inverters; Q1, Q2, Q3, and Q4 are MOSFETs (i.e., secondary-side switches) of the secondary-side active bridge, acting as high-frequency rectifiers; L1 is the self-inductance of the transmitting coil; L2 is the self-inductance of the receiving coil; M is the mutual inductance between the transmitting and receiving coils; C1 is the capacitance of the primary-side resonant compensation network; C2 is the capacitance of the secondary-side resonant compensation network; V1 is the primary-side DC input voltage; V2 is the secondary-side DC output voltage; i1 is the input current; i2 is the output current.

[0072] Equivalent circuit diagram of a wireless power transmission system with SS compensation topology, such as Figure 3 As shown, where v AB This refers to the input voltage; v CD Output voltage; L M =k·L1,L k1 =L k2 = (1-k)L1. k is the coupling coefficient between the transmitting coil and the receiving coil; L M For equivalent leakage inductance; L k1 L is the primary-side equivalent inductance. k2 This is the equivalent inductance of the secondary side (equivalent inductance of the secondary side).

[0073] The ratio of the common conduction time and switching period of switches S1 and S4 is defined as the primary side inward phase shift angle d1 (also known as the primary side inward phase shift angle). The ratio of the common conduction time and switching period of switches Q1 and Q4 is defined as the secondary side inward phase shift angle d2 (also known as the secondary side inward phase shift angle). The ratio of the delay hysteresis time and switching period between S1 and Q1 is defined as the outward phase shift angle. After Fourier decomposition, the input voltage v AB and output voltage v CD The ratio of the phase lag time and the switching period is defined as d. σ ,and

[0074] Therefore, although there are four distinct variables, there are actually only three degrees of freedom, meaning the state of the wireless charging system can be determined by a set of known d1, d2, and d3. (or d) σ )Sure.

[0075] The switching frequency of the dual-ended active H-bridge is set at the resonant frequency of the resonant network, and is defined as:

[0076]

[0077] Among them, f S f is the resonant frequency of the primary side; r This is the resonant frequency of the secondary side.

[0078] Input voltage (primary AC voltage) V AB and output side voltage (secondary side AC voltage) v CD The expression can be obtained from Fourier decomposition:

[0079]

[0080]

[0081] Where n is the series in the Fourier expansion; ω S Let ω be the angular frequency of the system. S =2πf S ; θ is an intermediate variable and has no specific physical meaning, as shown in formula (4); Input voltage (primary AC voltage) v AB and output voltage v CD Phase angle value of the delay between

[0082]

[0083]

[0084] According to Kirchhoff's voltage law and current law, the input current i1 and the output current i2 can be obtained, as shown in equation (6):

[0085]

[0086] Where j is the imaginary unit; an is an intermediate variable without a specific physical meaning, as shown in formula (7):

[0087]

[0088] Therefore, the effective value of the input-side current i1 defined by the equation can be derived. and the effective value of the output current i2 for:

[0089]

[0090]

[0091] Among them, B n.1 B n.2 B n.3 and B n.4 These are all intermediate variables without specific physical meaning, and their values ​​are shown in formula (10):

[0092]

[0093] Based on the definition of active power, the expression for output power (i.e., the model of a wireless power transmission system with SS compensation topology) can be obtained as follows:

[0094]

[0095] Among them, T S The switching cycle.

[0096] Both the dual-phase-shift modulation strategy (DPS) and the extended-phase-shift modulation strategy (EPS) are modulation methods with two degrees of freedom, and can be regarded as special cases of three-phase-shift modulation. In dual-phase-shift modulation, the inner phase shift angles of the active bridges on the primary and secondary sides are equal; while in extended-phase-shift modulation, the inner phase shift angle d2 of the active bridge on the secondary side is set to 0.5, as shown in equations (12) and (13).

[0097] DPS:d2=d1 (12).

[0098] EPS:d2=0.5 (13).

[0099] Substituting formula (12) into formula (11) yields the power model under dual phase-shift modulation; substituting formula (13) into formula (11) yields the power model under extended phase-shift (EPS) modulation.

[0100] Step 102: Determine the relationship of the primary phase shift angles based on system parameters, the internal phase shift angles of the dual-phase shift primary side, and the internal phase shift angles of the extended-phase shift primary side.

[0101] Among them, the relationship of the primary side internal phase shift angle is the relationship between the primary side internal phase shift angle of the dual-phase shift and the primary side internal phase shift angle of the extended phase shift. The primary side internal phase shift angle of the dual-phase shift is the primary side internal phase shift angle under the dual-phase shift modulation strategy, and the primary side internal phase shift angle of the extended phase shift is the primary side internal phase shift angle under the extended phase shift modulation strategy.

[0102] Step 103: Based on the relationship of the phase shift angle in the primary side and the phase shift angle value in the primary side of the dual-phase shift, determine the phase shift angle value in the primary side of the extended phase shift.

[0103] Specifically, the phase shift angle value of the primary side under the extended phase shift modulation strategy is the phase shift angle value of the primary side.

[0104] Step 104: Calculate the dual-phase shift output power.

[0105] Step 104 includes:

[0106] Step 1041: Calculate the outer phase shift angle of the dual-phase shift based on the system parameters and the inner phase shift angle value of the primary phase shift side.

[0107] Specifically, the outer phase shift angle value under the dual phase shift modulation strategy is the outer phase shift angle value.

[0108] Step 1042: Calculate the dual-phase output power based on the primary side DC input voltage, angular frequency, dual-phase primary side inner phase shift angle, self-inductance of the transmitting coil, coupling coefficient, secondary side DC output voltage, dual-phase outer phase shift angle, and dual-phase secondary side inner phase shift angle; the dual-phase secondary side inner phase shift angle is equal to the dual-phase primary side inner phase shift angle.

[0109] Specifically, the dual-phase-shift output power is the output power under the dual-phase-shift modulation strategy.

[0110] Step 105: Calculate the extended phase-shifted output power.

[0111] Step 105 includes:

[0112] Step 1051: Calculate the extended phase shift angle value based on the system parameters and the internal phase shift angle value of the primary phase shift side.

[0113] Specifically, the extended phase shift angle is the external phase shift angle value under the extended phase shift modulation strategy.

[0114] Step 1052: Calculate the extended phase-shift output power based on the primary side DC input voltage, angular frequency, extended phase-shift primary side internal phase-shift angle value, self-inductance of the transmitting coil, coupling coefficient, secondary side DC output voltage, extended phase-shift external phase-shift angle value, and extended phase-shift secondary side internal phase-shift angle value; the extended phase-shift secondary side internal phase-shift angle value is 0.5.

[0115] Specifically, extended phase-shift output power refers to the output power under the extended phase-shift modulation strategy.

[0116] Step 106: Determine the target modulation strategy of the target system based on the dual phase-shift output power and the extended phase-shift output power.

[0117] As an optional implementation, the process of determining the minimum current in step 101 specifically includes:

[0118] Obtain the dead time and junction capacitance of the switching transistor.

[0119] The minimum current is determined based on the primary side DC input voltage, dead time, and junction capacitance.

[0120] As an optional implementation, step 102 specifically includes:

[0121] The dual-phase shift current function is constructed based on system parameters and the phase shift angle of the primary side of the dual-phase shift.

[0122] Specifically, the dual-phase-shift current function is the current function under the dual-phase-shift modulation strategy.

[0123] The extended phase-shifting current function is constructed based on system parameters and the phase-shifting angle within the primary side of the extended phase-shifting phase shifter.

[0124] Specifically, the extended phase-shifting current function is the current function under the extended phase-shifting modulation strategy.

[0125] Based on the dual-phase-shifting current function and the extended phase-shifting current function, the relationship of the phase-shifting angle in the primary side is determined.

[0126] Specifically, soft switching is crucial in wireless power transmission systems. Because high-power systems operate at high switching frequencies, the inverter's MOSFETs need to operate in a zero-voltage on-state to reduce system losses and EMI interference, thereby ensuring stable and efficient system operation.

[0127] First, the primary-side active bridge switch (referring to...) Figure 2 We will analyze the transistors S1, S2, S3, and S4. Taking S1 as an example, since the dead time is very short, the junction capacitance C of the switching transistor S1 can be... oss.p The charging and discharging currents are considered to be constant, therefore the amount of charge Q stored on it is... CS1 The moment at the start of the dead zone can be represented by equation (14):

[0128]

[0129] Among them, C oss.p This refers to the junction capacitance of switching transistors S1, S2, S3, or S4. The specific value can be found in the datasheet based on the transistor model. This is the amount of charge stored in the junction capacitance of the switching transistor S1.

[0130] In this embodiment of the invention, S1, S2, S3, S4, Q1, Q2, Q3, and Q4 are all switching transistors of the same type. When the junction capacitance of one switching transistor (such as S1) discharges, its complementary switching transistor (i.e., S2) (complementary switching transistors refer to two switching transistors on the same bridge arm, such as...) Figure 2 The junction capacitances of S1 and S2, S3 and S4, Q1 and Q2, and Q3 and Q4 in the equation will necessarily be charged, and the charging current i of S2 will be charged.CS2 and the discharge current i of S1 CS1 Equal, i CS1 =i CS2 Therefore, the soft-switching condition for S1 (when this condition is met, zero-voltage conduction of the switching transistor S1 can be achieved, resulting in lower switching losses) can be expressed as:

[0131]

[0132] Among them, I ZVS.p The minimum current required to achieve zero-voltage turn-on for the primary-side switching transistor; T d Dead time, The identity sign means that the I on the right side... ZVS.p It is a constant value and does not change over time.

[0133] Similarly, the minimum current I required to achieve zero-voltage turn-on of all switches in the secondary active bridge is... ZVS.S for:

[0134]

[0135] Among them, C oss.S It is the junction capacitance of the secondary-side switching transistors Q1, Q2, Q3, or Q4.

[0136] Let I ZVS.P =I ZVS.S =I ZVS I ZVS The minimum current required for all switching transistors to conduct at zero voltage is given in Table 1.

[0137] Table 1 Zero-voltage turn-on conditions for all switching transistors

[0138]

[0139] Where i1(t) S1 ) represents the current value of i1 at the moment S1 is turned on; i1(t) S3 i1 is the current value at the moment S3 is turned on; i2(t) is the current value at the moment S3 is turned on. Q1 i2 is the current value at the moment Q1 is turned on; i2(t) is the current value of i2. Q3 ) represents the current value of i2 when Q3 is turned on.

[0140] Traditional three-phase-shift control trajectory generation methods have certain limitations. This invention abstracts the three-phase-shift modulation problem into an optimization problem as shown in equation (17). Where i 1.RMS and i 2.RMS It concerns the phase shift angles d1, d2, and... The function.

[0141]

[0142] Among them, P target Let d1 be the target output power value, serving as the equality constraint for the optimization problem; and let the zero-voltage conduction condition and boundary conditions serve as the inequality constraint for the optimization problem. Let I be the objective function value. The goal of the optimization problem is to minimize I. The essence of this optimization problem is to minimize I by selecting a suitable set of values ​​for d1 and d2, while satisfying the constraints.

[0143] For extended phase-shift modulation:

[0144] Since the extended phase-shift modulation mode is more suitable for applications with lower output voltage, d2 is always equal to 0.5. The external phase shift angle is constrained by the internal phase shift angle of the primary side and will be less than π / 2. Therefore, the secondary side switches are all in a zero-voltage conduction state. Only the ZVS condition of the primary side switches needs to be considered. Due to the symmetry of the waveform, only the ZVS condition of S1 needs to be calculated. From Table 1 and Equation (17), it can be seen that when the zero-voltage conduction condition of S1 is exactly satisfied, its zero-voltage conduction condition can be rearranged as follows:

[0145]

[0146] Among them, c1 and c n These are all intermediate quantities with no physical meaning; they are only used to make the formula look simpler.

[0147] Outward phase angle The trajectory of ( can be re-represented as:)

[0148]

[0149] in, To meet the external phase angle value when the switching transistor S1 is soft-switched (zero voltage conduction).

[0150] For dual-phase-shift modulation:

[0151] When the wireless power transmission system operates in dual-phase-shift modulation mode, since d1 = d2, the ZVS conditions on both the primary and secondary sides must be considered. The ZVS of the active bridge switch on the primary side is the same as above (i.e., formula (18) - formula (20)), and the ZVS boundary of the active bridge on the secondary side only needs to consider the ZVS condition of Q3. When the zero-voltage conduction condition of Q3 is exactly realized, the external phase angle is... It can be represented as:

[0152]

[0153] in, To meet the external phase angle requirements when the switching transistor Q3 is soft-switched (zero-voltage conduction), e1 and en It is an intermediate quantity and has no actual physical meaning.

[0154]

[0155] Therefore, when the wireless power transmission system is controlled by dual-phase-shift modulation, the zero-voltage turn-on condition of both S1 and Q3 should be satisfied. At this time, the outer phase shift angle under the dual-phase-shift modulation strategy... It can be determined by the following formula:

[0156]

[0157] Where G is the DC voltage gain, G = V2 / V1.

[0158] In summary, the phase shift angles for each mode are as follows:

[0159]

[0160] To ensure zero-voltage conduction of the wireless transmission system across the entire operating range, the phase angle is shifted outward. Equation (25) must be followed:

[0161]

[0162] Among them, I DPS For the dual-phase shift current (i.e., I under the dual-phase shift modulation strategy), I EPS To extend the phase-shifting current (i.e., to extend I under the phase-shifting modulation strategy). DPS and I EPS Both are functions of d1 and d2. The control variable d1 can be generated by the PI controller based on the load voltage, load current, or load power. At this point, the optimal control sequence for the wireless power transfer system is completely determined.

[0163] After determining the generation process of the optimized control sequence under the dual-phase-shift modulation (DPM) and extended-phase-shift modulation (EPM) strategies, another problem to be solved is identifying the boundaries of the DPM and EPM strategies across the entire operating range. This invention proposes a method to avoid complex calculations of their cost functions: make the DPM and EPM strategies have the same cost, compare their output power; the higher the output power, the better the performance. That is, let I... DPS.1 =I EPS.1 (I DPS.1 For the fundamental current component under the dual-phase-shift modulation strategy, I EPS.1 To extend the current fundamental component under the phase-shift modulation strategy (its accuracy is already sufficient), d can be obtained. 1,DPS and d 1,EPS The relationship between them is:

[0164]

[0165] Where, d 1,EPS To extend the primary side phase shift angle (i.e., d) under the phase shift modulation strategy; 1,DPS This is the first-side internal phase shift angle under the dual-phase-shift modulation strategy.

[0166] Therefore, at the same cost, once the value of d1.DPS is known, the corresponding d 1,EPS This can be obtained from the formula. Therefore, d is respectively... 1,DPS and d 1,EPS Substituting the output power expressions of the dual-phase-shift modulation strategy (i.e., formula (12)) and the extended-phase-shift modulation strategy (i.e., formula (13)) into the output power expressions of the dual-phase-shift modulation strategy, respectively, yields the dual-phase-shift output power and the extended-phase-shift output power.

[0167] As an optional implementation, step 1042 specifically includes:

[0168] The voltage on the dual-phase-shifted input side is calculated based on the primary-side DC input voltage, angular frequency, and the internal phase-shifting angle of the dual-phase-shifted primary side.

[0169] Specifically, the dual-phase-shift input-side voltage is the input-side voltage under the dual-phase-shift modulation strategy.

[0170] The output voltage of the dual-phase shifted side is calculated based on the secondary side DC output voltage, angular frequency, inner phase shift angle value of the dual-phase shifted secondary side, and outer phase shift angle value of the dual-phase shifted side.

[0171] Specifically, the dual-phase-shift output voltage is the output voltage under the dual-phase-shift modulation strategy.

[0172] The dual-phase output power is calculated based on the coupling coefficient, angular frequency, self-inductance of the transmitting coil, dual-phase input voltage, dual-phase output voltage, and dual-phase delay phase angle.

[0173] As an optional implementation, the dual-phase-shifted output voltage is calculated based on the secondary-side DC output voltage, angular frequency, and the inner and outer phase-shifted angles of the dual-phase-shifted secondary side. Specifically, this includes:

[0174] The phase delay angle of the dual-phase shift is calculated based on the external phase shift angle and the internal phase shift angle of the primary side of the dual-phase shift; the phase delay angle is the phase angle value of the delay between the input voltage and the output voltage of the dual-phase shift under the dual-phase shift modulation strategy.

[0175] The output voltage of the dual-phase shifted phase is calculated based on the secondary side DC output voltage, angular frequency, internal phase shift angle of the dual-phase shifted secondary side, and phase delay angle of the dual-phase shifted phase.

[0176] As an optional implementation, step 1052 specifically includes:

[0177] The extended phase-shift input voltage is calculated based on the primary side DC input voltage, angular frequency, and the phase shift angle value within the extended phase-shift primary side.

[0178] Specifically, the extended phase-shift input-side voltage is the input-side voltage under the extended phase-shift modulation strategy.

[0179] The extended phase-shifted output voltage is calculated based on the secondary side DC output voltage, angular frequency, extended phase-shifted secondary side inner phase-shift angle value, and extended phase-shifted outer phase-shift angle value.

[0180] Specifically, the extended phase-shift output voltage is the output voltage under the extended phase-shift modulation strategy.

[0181] The extended phase-shift output power is calculated based on the coupling coefficient, angular frequency, self-inductance of the transmitting coil, extended phase-shift input voltage, extended phase-shift output voltage, and extended phase-shift delay phase angle.

[0182] As an optional implementation, the extended phase-shifted output voltage is calculated based on the secondary-side DC output voltage, angular frequency, the extended phase-shifted secondary-side inner phase-shift angle value, and the extended phase-shifted outer phase-shift angle value, specifically including:

[0183] The extended phase shift delay phase angle is calculated based on the extended phase shift external phase shift angle and the extended phase shift primary side internal phase shift angle; the extended phase shift delay phase angle is the phase angle value of the delay between the extended phase shift input voltage and the extended phase shift output voltage under the extended phase shift modulation strategy.

[0184] The extended phase-shifted output voltage is calculated based on the secondary side DC output voltage, angular frequency, extended phase-shifted secondary side internal phase-shifted angle value, and extended phase-shifted delay phase angle value.

[0185] As an optional implementation, step 106 specifically includes:

[0186] When the dual-phase-shift output power is greater than the extended phase-shift output power, the dual-phase-shift modulation strategy is determined as the target modulation strategy.

[0187] When the dual-phase-shift output power is less than the extended-phase-shift output power, the extended-phase-shift modulation strategy is determined as the target modulation strategy.

[0188] When the dual-phase-shift output power equals the extended-phase-shift output power, the dual-phase-shift modulation strategy or the extended-phase-shift modulation strategy is determined as the target modulation strategy.

[0189] Example 2

[0190] Figure 4 This is a schematic diagram of the system structure for determining the modulation strategy of a wireless power transmission system according to Embodiment 2 of the present invention. Figure 4 As shown, the system for determining the modulation strategy of the wireless power transmission system in this embodiment includes:

[0191] The parameter determination module 201 is used to determine the system parameters of the target system and the internal phase shift angle value of the primary side of the dual-phase-shifting system. The system parameters include: primary side DC input voltage, secondary side DC output voltage, angular frequency, minimum current of the switching transistor when it is turned on at zero voltage, coupling coefficient, and self-inductance of the transmitting coil. The target system is a wireless power transmission system with SS compensation topology, and the coupling coefficient is the coupling coefficient between the transmitting coil and the receiving coil. The internal phase shift angle value of the primary side of the dual-phase-shifting system is the internal phase shift angle value of the primary side under the dual-phase-shifting modulation strategy.

[0192] The relationship determination module 202 is used to determine the relationship of the primary phase shift angle based on system parameters, the primary phase shift angle of the dual-phase shift and the primary phase shift angle of the extended phase shift. The relationship of the primary phase shift angle is the relationship between the primary phase shift angle of the dual-phase shift and the primary phase shift angle of the extended phase shift. The primary phase shift angle of the dual-phase shift is the primary phase shift angle under the dual-phase shift modulation strategy, and the primary phase shift angle of the extended phase shift is the primary phase shift angle under the extended phase shift modulation strategy.

[0193] The extended phase shifting primary side inner phase angle value determination module 203 is used to determine the extended phase shifting primary side inner phase angle value based on the relationship between the inner phase angles of the primary side and the inner phase angle values ​​of the primary side of the dual phase shifting.

[0194] Dual-phase-shift output power calculation module 204 is used for:

[0195] Based on the system parameters and the inner phase shift angle value of the primary phase shifter, the outer phase shift angle value of the dual phase shifter is calculated.

[0196] The dual-phase output power is calculated based on the primary side DC input voltage, angular frequency, internal phase shift angle of the primary side of the dual-phase shift, self-inductance of the transmitting coil, coupling coefficient, secondary side DC output voltage, external phase shift angle of the dual-phase shift, and internal phase shift angle of the secondary side of the dual-phase shift. The internal phase shift angle of the secondary side of the dual-phase shift is equal to the internal phase shift angle of the primary side of the dual-phase shift.

[0197] The extended phase-shift output power calculation module 205 is used for:

[0198] Based on the system parameters and the phase shift angle value inside the primary phase shifter, the phase shift angle value outside the primary phase shifter is calculated.

[0199] The extended phase-shift output power is calculated based on the primary side DC input voltage, angular frequency, extended phase-shift internal phase-shift angle value on the primary side, self-inductance of the transmitting coil, coupling coefficient, secondary side DC output voltage, extended phase-shift external phase-shift angle value, and extended phase-shift internal phase-shift angle value on the secondary side; the extended phase-shift internal phase-shift angle value on the secondary side is 0.5.

[0200] The target modulation strategy determination module 206 is used to determine the target modulation strategy of the target system based on the dual phase-shift output power and the extended phase-shift output power.

[0201] Example 3

[0202] An electronic device, comprising:

[0203] One or more processors.

[0204] A storage device on which one or more programs are stored.

[0205] When one or more programs are executed by one or more processors, the one or more processors implement the method for determining the modulation strategy of the wireless power transmission system as described in Example 1.

[0206] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0207] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for determining the modulation strategy of a wireless power transmission system, characterized in that, The method includes: The system parameters and the internal phase shift angle of the primary side of the dual-phase-shifting system are determined. The system parameters include: primary-side DC input voltage, secondary-side DC output voltage, angular frequency, minimum current of the switching transistor when it is turned on at zero voltage, coupling coefficient, and self-inductance of the transmitting coil. The target system is a wireless power transmission system with SS compensation topology. The coupling coefficient is the coupling coefficient between the transmitting coil and the receiving coil. The internal phase shift angle of the primary side of the dual-phase-shifting system is the internal phase shift angle of the primary side under the dual-phase-shifting modulation strategy. Based on the system parameters, the fundamental current component under the dual-phase-shift modulation strategy is made equal to the fundamental current component under the extended phase-shift modulation strategy, and the primary side internal phase shift angle relationship is determined; the primary side internal phase shift angle relationship is the relationship between the primary side internal phase shift angle of the dual-phase-shift modulation strategy and the primary side internal phase shift angle of the extended phase-shift modulation strategy; the primary side internal phase shift angle of the dual-phase-shift modulation strategy is the primary side internal phase shift angle under the dual-phase-shift modulation strategy, and the primary side internal phase shift angle of the extended phase-shift modulation strategy is the primary side internal phase shift angle under the extended phase-shift modulation strategy. Based on the primary phase shift angle relationship and the primary phase shift angle value of the dual-phase shift, the primary phase shift angle value of the extended phase shift is determined. For the dual-phase-shift modulation strategy: Based on the system parameters and the inner phase shift angle value of the primary phase shifter, the outer phase shift angle value of the dual phase shifter is calculated; The dual-phase output power is calculated based on the primary-side DC input voltage, the angular frequency, the inner phase shift angle of the primary side of the dual-phase shift, the self-inductance of the transmitting coil, the coupling coefficient, the secondary-side DC output voltage, the outer phase shift angle of the dual-phase shift, and the inner phase shift angle of the secondary side of the dual-phase shift; the inner phase shift angle of the secondary side of the dual-phase shift is equal to the inner phase shift angle of the primary side of the dual-phase shift. For extended phase-shift modulation strategies: Based on the system parameters and the extended phase shift angle value on the primary side, calculate the extended phase shift angle value. The extended phase-shift output power is calculated based on the primary side DC input voltage, the angular frequency, the extended phase-shift primary side inner phase-shift angle value, the self-inductance of the transmitting coil, the coupling coefficient, the secondary side DC output voltage, the extended phase-shift outer phase-shift angle value, and the extended phase-shift secondary side inner phase-shift angle value; the extended phase-shift secondary side inner phase-shift angle value is 0.

5. The target modulation strategy of the target system is determined based on the dual-phase-shift output power and the extended phase-shift output power.

2. The method for determining the modulation strategy of a wireless power transmission system according to claim 1, characterized in that, The process of determining the minimum current specifically includes: Obtain the dead time and junction capacitance of the switching transistor; The minimum current is determined based on the primary-side DC input voltage, the dead time, and the junction capacitance.

3. The method for determining the modulation strategy of a wireless power transmission system according to claim 1, characterized in that, Based on the system parameters, the fundamental current component under the dual-phase-shift modulation strategy is made equal to the fundamental current component under the extended phase-shift modulation strategy. The phase shift angle relationship on the primary side is then determined, specifically including: A dual-phase-shift current function is constructed based on the system parameters; the dual-phase-shift current function is the current function under the dual-phase-shift modulation strategy. An extended phase-shift current function is constructed based on the system parameters; the extended phase-shift current function is the current function under the extended phase-shift modulation strategy. Based on the dual-phase-shifting current function and the extended phase-shifting current function, the relationship of the phase-shifting angle on the primary side is determined.

4. The method for determining the modulation strategy of a wireless power transmission system according to claim 1, characterized in that, Based on the primary-side DC input voltage, the angular frequency, the inner phase shift angle of the primary side of the dual-phase shift, the self-inductance of the transmitting coil, the coupling coefficient, the secondary-side DC output voltage, the outer phase shift angle of the dual-phase shift, and the inner phase shift angle of the secondary side of the dual-phase shift, the dual-phase shift output power is calculated, specifically including: Calculate the dual-phase-shifted input side voltage based on the primary-side DC input voltage, the angular frequency, and the internal phase-shifting angle value of the dual-phase-shifted primary side. The dual-phase shift delay phase angle is calculated based on the external phase shift angle value and the internal phase shift angle value of the primary side of the dual-phase shift; the dual-phase shift delay phase angle value is the phase angle value of the delay between the dual-phase shift input voltage and the dual-phase shift output voltage under the dual-phase shift modulation strategy. The dual-phase output voltage is calculated based on the secondary-side DC output voltage, the angular frequency, the internal phase-shift angle value of the dual-phase-shift secondary side, and the dual-phase-shift delay phase angle value. The dual-phase output power is calculated based on the coupling coefficient, the angular frequency, the self-inductance of the transmitting coil, the dual-phase input voltage, the dual-phase output voltage, and the dual-phase delay phase angle.

5. The method for determining the modulation strategy of a wireless power transmission system according to claim 1, characterized in that, Based on the primary-side DC input voltage, the angular frequency, the extended phase-shifting primary-side inner phase-shifting angle, the self-inductance of the transmitting coil, the coupling coefficient, the secondary-side DC output voltage, the extended phase-shifting outer phase-shifting angle, and the extended phase-shifting secondary-side inner phase-shifting angle, the extended phase-shifting output power is calculated, specifically including: Calculate the extended phase-shift input side voltage based on the primary side DC input voltage, the angular frequency, and the extended phase-shift primary side internal phase-shift angle value; The extended phase shift delay phase angle is calculated based on the extended phase shift outer phase angle value and the extended phase shift primary side inner phase angle value; the extended phase shift delay phase angle value is the phase angle value of the delay between the extended phase shift input side voltage and the extended phase shift output side voltage under the extended phase shift modulation strategy. Based on the secondary-side DC output voltage, the angular frequency, the extended phase-shifting secondary-side internal phase-shifting angle value, and the extended phase-shifting delay phase angle value, calculate the extended phase-shifting output-side voltage; The extended phase-shift output power is calculated based on the coupling coefficient, the angular frequency, the self-inductance of the transmitting coil, the extended phase-shift input voltage, the extended phase-shift output voltage, and the extended phase-shift delay phase angle.

6. The method for determining the modulation strategy of a wireless power transmission system according to claim 1, characterized in that, The target modulation strategy of the target system is determined based on the dual-phase-shift output power and the extended phase-shift output power, specifically including: When the dual-phase-shift output power is greater than the extended phase-shift output power, the dual-phase-shift modulation strategy is determined as the target modulation strategy; When the dual-phase-shift output power is less than the extended-phase-shift output power, the extended-phase-shift modulation strategy is determined as the target modulation strategy; When the dual-phase-shift output power is equal to the extended-phase-shift output power, the dual-phase-shift modulation strategy or the extended-phase-shift modulation strategy is determined as the target modulation strategy.

7. A system for determining the modulation strategy of a wireless power transmission system, characterized in that, The system includes: The parameter determination module is used to determine the system parameters and the internal phase shift angle value of the primary side of the target system. The system parameters include: primary side DC input voltage, secondary side DC output voltage, angular frequency, minimum current of the switching transistor when it is turned on at zero voltage, coupling coefficient, and self-inductance of the transmitting coil. The target system is a wireless power transmission system with SS compensation topology, and the coupling coefficient is the coupling coefficient between the transmitting coil and the receiving coil. The internal phase shift angle value of the primary side of the dual-phase shift modulation strategy is the internal phase shift angle value of the primary side. The relationship determination module is used to determine the primary side internal phase shift angle relationship based on the system parameters, setting the fundamental current component under the dual-phase-shift modulation strategy equal to the fundamental current component under the extended phase-shift modulation strategy; the primary side internal phase shift angle relationship is the relationship between the primary side internal phase shift angle of the dual-phase-shift modulation strategy and the primary side internal phase shift angle of the extended phase-shift modulation strategy; the primary side internal phase shift angle of the dual-phase-shift modulation strategy is the primary side internal phase shift angle under the dual-phase-shift modulation strategy, and the primary side internal phase shift angle of the extended phase-shift modulation strategy is the primary side internal phase shift angle under the extended phase-shift modulation strategy. The extended phase shifting primary side inner phase shift angle value determination module is used to determine the extended phase shifting primary side inner phase shift angle value based on the inner phase shift angle relationship of the primary side and the inner phase shift angle value of the dual phase shifting primary side; The dual-phase-shift output power calculation module is used for: Based on the system parameters and the inner phase shift angle value of the primary phase shifter, the outer phase shift angle value of the dual phase shifter is calculated; The dual-phase output power is calculated based on the primary-side DC input voltage, the angular frequency, the inner phase shift angle of the primary side of the dual-phase shift, the self-inductance of the transmitting coil, the coupling coefficient, the secondary-side DC output voltage, the outer phase shift angle of the dual-phase shift, and the inner phase shift angle of the secondary side of the dual-phase shift; the inner phase shift angle of the secondary side of the dual-phase shift is equal to the inner phase shift angle of the primary side of the dual-phase shift. The extended phase-shift output power calculation module is used for: Based on the system parameters and the extended phase shift angle value on the primary side, calculate the extended phase shift angle value. The extended phase-shift output power is calculated based on the primary side DC input voltage, the angular frequency, the extended phase-shift primary side inner phase-shift angle value, the self-inductance of the transmitting coil, the coupling coefficient, the secondary side DC output voltage, the extended phase-shift outer phase-shift angle value, and the extended phase-shift secondary side inner phase-shift angle value; the extended phase-shift secondary side inner phase-shift angle value is 0.

5. The target modulation strategy determination module is used to determine the target modulation strategy of the target system based on the dual phase-shift output power and the extended phase-shift output power.

8. An electronic device, characterized in that, include: One or more processors; A storage device on which one or more programs are stored; When the one or more programs are executed by the one or more processors, the one or more processors implement the method for determining the modulation strategy of a wireless power transmission system as described in any one of claims 1 to 6.

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