A wireless charging system suitable for zero-phase-angle constant-current constant-voltage and a parameter design method thereof

Abstract

This invention proposes a wireless charging system suitable for zero-phase-angle constant current and constant voltage and its parameter design method, including a DC voltage source U. in Inverter unit, primary-side compensation network, transmitting coil L p2 Receiver coil L s The DC power supply U consists of a secondary compensation network, a rectifier unit, and a load resistor R. in Connect the inverter unit, which is connected to the primary-side compensation network and the transmitting coil L. p2 The transmitting coil L p2 With receiving coil L s Mutual inductance, the receiving coil L s The secondary compensation network is connected to the rectifier unit, which is connected to the load resistor R. This invention does not require the introduction of switches or complex control circuits, eliminating power losses and heat dissipation problems associated with switching switches and control circuits. By constructing the topology and setting the parameter relationships, it achieves constant current / constant voltage working mode switching only through two fixed operating frequencies under varying coupling coefficients. Both working modes satisfy zero phase angle, resulting in high system transmission efficiency.

Description

Technical Field

[0001] This invention relates to the field of wireless charging technology, specifically to a wireless charging system suitable for zero-phase-angle constant current and constant voltage and its parameter design method. Background Technology

[0002] Most electrical devices currently use lithium or lead-acid batteries for power. Charging these loads requires a constant current followed by a constant voltage charging mode, and the charging voltage or current cannot fluctuate significantly with changes in the load. There are currently three methods for wireless power transfer systems to achieve constant current / constant voltage output.

[0003] Method 1: Achieving constant current / constant voltage output by adjusting the system's operating frequency. Current methods of changing the wireless charging system's operating frequency can only achieve constant current / constant voltage output with a zero phase angle under a fixed coupling coefficient. When the coupling coefficient changes, the system only exhibits constant current output characteristics or only constant voltage output characteristics, and some systems even lack both, posing certain difficulties in practical applications.

[0004] Method 2: Achieving constant current / constant voltage output by switching the topology using a switch. Switching the topology increases system complexity. The introduction of the switch introduces losses, which is detrimental to system efficiency. Furthermore, in high-power wireless power supply systems, these losses can cause significant temperature rise in the devices, leading to heat dissipation issues.

[0005] Method 3: Achieving constant current / constant voltage output through an external control circuit. The introduction of a control circuit also increases system complexity, introduces losses, and can cause excessive device temperature rise in high-power applications. Furthermore, Method 3 places higher demands on the control circuit. For the same topology, when the excitation frequency remains constant, the wireless power supply system itself only has constant current or constant voltage output characteristics, and only has zero phase angle in one output state. When the system needs to operate in both constant current and constant voltage output states, one output mode is entirely achieved by the control circuit. When the coupling coefficient or load variation range is large, the adjustable range of the control circuit needs to be wider, and situations may even occur that exceed the adjustable range of the control circuit.

[0006] Therefore, there is an urgent need for a topology and parameter design method suitable for zero-phase-angle constant current / constant voltage wireless charging loads, so that the system can switch between constant current and constant voltage working modes by switching only two fixed frequencies under the condition of variable coupling coefficient, and both working modes meet the zero-phase angle requirement. Summary of the Invention

[0007] To address the issue of switching between constant current and constant voltage charging processes for loads such as lithium batteries and lead-acid batteries in wireless power transmission systems, this invention proposes a wireless charging system and its parameter design method suitable for zero-phase-angle constant current and constant voltage charging. This system achieves constant current / constant voltage mode switching only through two fixed operating frequencies under varying coupling coefficients, with both operating modes satisfying zero phase angle.

[0008] This invention is achieved through the following scheme:

[0009] A primary-side circuit suitable for a zero-phase-angle constant-current and constant-voltage wireless charging system:

[0010] The primary circuit includes a DC power supply U. in Inverter unit, primary-side compensation network and transmitting coil L p2 ;

[0011] The primary-side compensation network includes a primary-side compensation inductor L. p0 and L p1 Primary-side compensation capacitor C p0 C p11 C p12 and C p2 ;

[0012] The DC power supply U in The inverter unit is connected to the primary-side compensation network, which in turn is connected to the transmitting coil L. p2 .

[0013] Furthermore,

[0014] The inverter unit includes four switching transistors Q1, Q2, Q3 and Q4;

[0015] The DC voltage source U in The positive terminals are connected to one end of the switching transistors Q1 and Q2, respectively;

[0016] The other end of switching transistor Q1 is connected to one end of switching transistor Q3 and the primary-side compensation capacitor C, respectively. p11 One end, primary-side compensation capacitor C p12 One end and the primary side transmitting coil L p2 One end is connected;

[0017] The other end of switching transistor Q2, one end of switching transistor Q4, and the primary-side compensating inductor L p1 One end is connected;

[0018] DC voltage source U in The negative terminals are connected to the other ends of switching transistors Q3 and Q4, respectively;

[0019] The primary-side compensation inductor L p1The other end is connected to the primary compensation capacitor C. p11 The other end, primary-side compensating inductor L p0 One end is connected;

[0020] The primary-side compensation inductor L p0 The other end is connected to the primary-side compensation capacitor C p0 One end is connected;

[0021] Primary-side compensation capacitor C p0 The other end is connected to the primary compensation capacitor C. p12 The other end and the primary-side compensation capacitor C p2 One end is connected;

[0022] Primary-side compensation capacitor C p2 The other end is connected to the primary side transmitting coil L p2 The other end is connected.

[0023] A wireless charging system suitable for zero-phase-angle constant current and constant voltage:

[0024] The wireless charging system includes a primary-side circuit and a secondary-side circuit.

[0025] The primary-side circuit is the primary-side circuit described above;

[0026] The secondary circuit includes a receiving coil L s Secondary-side compensation network, rectifier unit, and load resistor R;

[0027] The secondary-side compensation network includes a secondary-side compensation inductor L. s0 Secondary side compensation capacitor C s and C s0 ;

[0028] The transmitting coil L p2 With receiving coil L s1 Mutual inductance, the transmitting coil L p2 A secondary-side compensation network is connected, which is connected to a rectifier unit, which is connected to a load resistor R.

[0029] Furthermore,

[0030] The rectifier unit includes four diodes D1, D2, D3, and D4, and a capacitor C0;

[0031] One end of the load resistor R is connected to one end of the capacitor C0, the negative terminal of diode D1, and the negative terminal of diode D2, respectively.

[0032] The positive terminal of diode D1 is connected to the negative terminal of diode D3 and the secondary-side compensation capacitor C, respectively. s0 One end and secondary compensation inductor L s0One end is connected;

[0033] The other end of the load resistor R is connected to the other end of the capacitor C0, the positive terminal of diode D3, and the positive terminal of diode D4, respectively.

[0034] The positive terminal of diode D2 is connected to the negative terminal of diode D4 and the receiving coil L, respectively. s1 One end is connected;

[0035] The receiving coil L s1 The other end is connected to the secondary compensation capacitor C s One end is connected;

[0036] Secondary side compensation capacitor C s The other end is connected to the secondary compensation capacitor C. s0 The other end and the secondary compensation inductor L s0 The other end is connected.

[0037] A parameter design method for a zero-phase-angle constant-current and constant-voltage wireless charging system:

[0038] The parameter design method specifically includes the following steps:

[0039] Step 1: Construct a topology that simultaneously exhibits constant current / constant voltage output characteristics under varying coupling coefficients;

[0040] Step 2: When the topology has constant current output characteristics, the transmitting coil L p2 Primary-side compensating inductor L p1 Primary-side compensation capacitor C p11 C p12 and C p2 Secondary receiving coil L s Secondary compensation inductor L s0 Secondary side compensation capacitor C s and C s0 The relationship model that is satisfied is:

[0041]

[0042] Where, ω CC ω is the angular frequency corresponding to the constant current mode, and j is the imaginary number.

[0043] Step 3: When the topology has constant voltage output characteristics, the primary-side compensation inductor L p1 Primary-side compensation capacitor C p11 and C p12 Secondary receiving coil L s Secondary compensation inductor L s0 Secondary side compensation capacitor C s and C s0The relationship model that is satisfied is:

[0044]

[0045] Where, ω CV This is the angular frequency corresponding to the constant voltage mode;

[0046] Step 4: Based on the solution of the relationship model in Steps 2 and 3, obtain the operating angular frequencies of the system when operating in constant current and constant voltage modes respectively:

[0047]

[0048] Where: λ p This is the ratio of the primary-side capacitance.

[0049] Step 5: Add compensation inductor L p0 and compensation capacitor C p0 The series topology compensates for the primary side, achieving zero-phase output in constant current mode, with the transmitting coil L... p2 Primary-side compensating inductor L p1 Primary-side compensation capacitor C p2 Compensating inductor L p0 and compensation capacitor C p0 The relational model is as follows:

[0050]

[0051] Step 6: Based on the solution in Step 5, the compensation inductance L can be obtained. p0 Compensation capacitor C p0 Relational model:

[0052]

[0053] An electronic device includes a memory and a processor, the memory storing a computer program, characterized in that the processor executes the computer program to implement the steps of the above-described method.

[0054] A computer-readable storage medium for storing computer instructions, characterized in that the computer instructions, when executed by a processor, implement the steps of the above-described method.

[0055] Beneficial effects of the invention

[0056] (1) By constructing the topology and setting the parameter relationship, this invention achieves the switching between constant current and constant voltage working modes by switching between two fixed working frequencies under the condition of variable coupling coefficient, and both working modes satisfy zero phase angle;

[0057] (2) Compared with existing methods for switching between constant current and constant voltage modes, this invention does not require the introduction of a switch for topology switching, nor does it require the introduction of complex control circuits. It eliminates the power loss and heat dissipation problems of switching switches, control circuits, etc. It can achieve the switching between constant current and constant voltage modes by switching between two fixed operating frequencies, and the system has high transmission efficiency. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of a topology circuit suitable for a zero-phase-angle constant current / constant voltage wireless charging load according to the present invention;

[0059] Figure 2 This is a topology with constant current / constant voltage output characteristics according to one embodiment of the present invention;

[0060] Figure 3 This is a topological structure in which compensation topology is added to the primary edges in one embodiment of the present invention;

[0061] Figure 4 The transconductance gain and voltage gain vary with load and coupling coefficient according to one embodiment of the present invention; (a) transconductance gain; (b) voltage gain;

[0062] Figure 5 The input impedance angle varies with load and coupling coefficient in one embodiment of the present invention; (a) constant current mode; (b) constant voltage mode. Detailed Implementation

[0063] 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.

[0064] Combination Figures 1 to 5 ,

[0065] A primary-side circuit suitable for a zero-phase-angle constant-current and constant-voltage wireless charging system:

[0066] The primary circuit includes a DC power supply U. in Inverter unit, primary-side compensation network and transmitting coil L p2 ;

[0067] The primary-side compensation network includes a primary-side compensation inductor L. p0 and L p1 Primary-side compensation capacitor C p0 C p11 C p12 and C p2 ;

[0068] The DC power supply U in The inverter unit is connected to the primary-side compensation network, which in turn is connected to the transmitting coil L. p2 .

[0069] The inverter unit includes four switching transistors Q1, Q2, Q3 and Q4;

[0070] The DC voltage source U in The positive terminals are connected to one end of the switching transistors Q1 and Q2, respectively;

[0071] The other end of switching transistor Q1 is connected to one end of switching transistor Q3 and the primary-side compensation capacitor C, respectively. p11 One end, primary-side compensation capacitor C p12 One end and the primary side transmitting coil L p2 One end is connected;

[0072] The other end of switching transistor Q2, one end of switching transistor Q4, and the primary-side compensating inductor L p1 One end is connected;

[0073] DC voltage source U in The negative terminals are connected to the other ends of switching transistors Q3 and Q4, respectively;

[0074] The primary-side compensation inductor L p1 The other end is connected to the primary compensation capacitor C. p11 The other end, primary-side compensating inductor L p0 One end is connected;

[0075] The primary-side compensation inductor L p0 The other end is connected to the primary-side compensation capacitor C p0 One end is connected;

[0076] Primary-side compensation capacitor C p0 The other end is connected to the primary compensation capacitor C. p12 The other end and the primary-side compensation capacitor C p2 One end is connected;

[0077] Primary-side compensation capacitor C p2 The other end is connected to the primary side transmitting coil L p2 The other end is connected.

[0078] A wireless charging system suitable for zero-phase-angle constant current and constant voltage:

[0079] The wireless charging system includes a primary-side circuit and a secondary-side circuit.

[0080] The primary-side circuit is the primary-side circuit described above;

[0081] The secondary circuit includes a receiving coil L s Secondary-side compensation network, rectifier unit, and load resistor R;

[0082] The secondary-side compensation network includes a secondary-side compensation inductor L. s0 Secondary side compensation capacitor C s and C s0 ;

[0083] The transmitting coil L p2 With receiving coil L s1 Mutual inductance, the transmitting coil L p2 A secondary-side compensation network is connected, which is connected to a rectifier unit, which is connected to a load resistor R.

[0084] The rectifier unit includes four diodes D1, D2, D3, and D4, and a capacitor C0;

[0085] One end of the load resistor R is connected to one end of the capacitor C0, the negative terminal of diode D1, and the negative terminal of diode D2, respectively.

[0086] The positive terminal of diode D1 is connected to the negative terminal of diode D3 and the secondary-side compensation capacitor C, respectively. s0 One end and secondary compensation inductor L s0 One end is connected;

[0087] The other end of the load resistor R is connected to the other end of the capacitor C0, the positive terminal of diode D3, and the positive terminal of diode D4, respectively.

[0088] The positive terminal of diode D2 is connected to the negative terminal of diode D4 and the receiving coil L, respectively. s1 One end is connected;

[0089] The receiving coil L s1 The other end is connected to the secondary compensation capacitor C s One end is connected;

[0090] Secondary side compensation capacitor C s The other end is connected to the secondary compensation capacitor C. s0 The other end and the secondary compensation inductor L s0 The other end is connected.

[0091] A parameter design method for a zero-phase-angle constant-current and constant-voltage wireless charging system:

[0092] The parameter design method specifically includes the following steps:

[0093] Step 1: Construct a topology that simultaneously exhibits constant current / constant voltage output characteristics under varying coupling coefficients;

[0094] Step 2: When the topology has constant current output characteristics, the transmitting coil L p2 Primary-side compensating inductor L p1 Primary-side compensation capacitor C p11 C p12 and C p2 Secondary receiving coil L s Secondary compensation inductor L s0 Secondary side compensation capacitor C s and C s0 The relationship model that is satisfied is:

[0095]

[0096] Where, ω CC ω is the angular frequency corresponding to the constant current mode, and j is the imaginary number.

[0097] Step 3: When the topology has constant voltage output characteristics, the primary-side compensation inductor L p1 Primary-side compensation capacitor C p11 and C p12 Secondary receiving coil L s Secondary compensation inductor L s0 Secondary side compensation capacitor C s and C s0 The relationship model that is satisfied is:

[0098]

[0099] Where, ω CV This is the angular frequency corresponding to the constant voltage mode;

[0100] Step 4: Based on the solution of the relationship model in Steps 2 and 3, obtain the operating angular frequencies of the system when operating in constant current and constant voltage modes respectively:

[0101]

[0102] Where: λ p This is the ratio of the primary-side capacitance.

[0103] By setting the system parameter relationships in steps 2-4, the constructed topology has constant current / constant voltage output characteristics under varying coupling coefficients, but only has zero phase angle output characteristics in constant voltage mode.

[0104] Step 5: Without disrupting the zero-phase-angle output characteristics of the system in constant current, constant voltage, and constant voltage modes, a compensation inductor L is added. p0 and compensation capacitor C p0 The series topology compensates for the primary side, achieving zero-phase output in constant current mode, with the transmitting coil L...p2 Primary-side compensating inductor L p1 Primary-side compensation capacitor C p2 Compensating inductor L p0 and compensation capacitor C p0 The relational model is as follows:

[0105]

[0106] Step 6: Based on the solution in Step 5, the compensation inductance L can be obtained. p0 Compensation capacitor C p0 Relational model:

[0107]

[0108] An electronic device includes a memory and a processor, the memory storing a computer program, characterized in that the processor executes the computer program to implement the steps of the above-described method.

[0109] A computer-readable storage medium for storing computer instructions, characterized in that the computer instructions, when executed by a processor, implement the steps of the above-described method.

[0110] This embodiment illustrates a topology parameter design method for a zero-phase-angle constant current / constant voltage wireless charging load. It achieves constant current / constant voltage working mode switching by switching only two fixed working frequencies under varying coupling coefficients, and both working modes satisfy zero phase angle.

[0111] The parameters of the topology, determined using the parameter design method described above, are shown in Table 1. Among them, the constant current output current is 4A, the constant voltage output voltage is 48V, and the transmission power is 192W.

[0112]

[0113] Table 1 Topology parameters

[0114] The transconductance gain and voltage gain of the wireless power transfer system vary with the coupling coefficient and load, respectively, as follows: Figure 4 As shown.

[0115] according to Figure 4 (a) It can be seen that the transconductance gain of the system decreases as the coupling coefficient increases. When the coupling coefficient of the system is fixed and the load changes, the transconductance gain of the system remains constant. Therefore, it can be seen that the system has constant current output characteristics.

[0116] according to Figure 4 (b) It can be seen that the voltage gain of the system increases with the increase of the coupling coefficient. When the coupling coefficient remains unchanged and the load changes, the voltage gain of the system remains constant. Therefore, it can be seen that the system has constant voltage output characteristics.

[0117] The input impedance angle of the system varies with load and coupling coefficient in both operating modes as follows: Figure 5 As shown, due to the influence of the device's internal resistance, the input impedance angle is not equal to 0°.

[0118] according to Figure 5 (a) It can be seen that when the load value is smaller and the coupling coefficient is larger, the input impedance angle of the system corresponding to the constant current mode is larger. However, under the constant current mode, the maximum absolute value of the maximum input impedance angle does not exceed 2.0°. Similarly, the coupling coefficient increases with the increase of the coupling coefficient and the decrease of the load, but the maximum absolute value of the input impedance angle does not exceed 0.49°.

[0119] The foregoing has provided a detailed description of a wireless charging system suitable for zero-phase-angle constant current and constant voltage, and its parameter design method. The principles and implementation methods of the present invention have been explained. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A primary-side circuit suitable for a zero-phase-angle constant-current and constant-voltage wireless charging system, characterized in that: The primary circuit includes a DC power supply. U in Inverter unit, primary-side compensation network and transmitting coil L p2 ; The inverter unit includes four switching transistors. Q 1. Q 2. Q 3 and Q 4; The primary-side compensation network includes a primary-side compensation inductor. L p0 and L p1 Primary-side compensation capacitor C p0 , C p11 , C p12 and C p2 ; The DC power supply U in The inverter unit is connected to the primary-side compensation network, which in turn is connected to the transmitting coil. L p2 ; The DC power supply U in The positive terminals are respectively connected to the switching transistor. Q 1 and Q Connect one end of 2; Switching transistor Q The other end of 1 is connected to the switching transistor. Q One end of 3, primary-side compensation capacitor C p11 One end, primary-side compensation capacitor C p12 one end and the primary side transmitting coil L p2 One end is connected; Switching transistor Q The other end of 2 is connected to the switching transistor. Q One end of 4 and the primary-side compensating inductor L p1 One end is connected; DC power supply U in The negative terminals are respectively connected to the switching transistor. Q 3 and Q Connect the other end of 4; The primary-side compensation inductor L p1 The other end is connected to the primary compensation capacitor. C p11 The other end, primary-side compensating inductor L p0 One end is connected; The primary-side compensation inductor L p0 The other end is connected to the primary-side compensation capacitor. C p0 One end is connected; Primary-side compensation capacitor C p0 The other end is connected to the primary compensation capacitor. C p12 The other end and the primary-side compensation capacitor C p2 One end is connected; Primary-side compensation capacitor C p2 The other end is connected to the primary side transmitting coil L p2 The other end is connected.

2. A wireless charging system suitable for zero-phase-angle constant current and constant voltage, characterized in that: The wireless charging system includes a primary-side circuit and a secondary-side circuit. The primary-side circuit is the primary-side circuit as described in claim 1; The secondary circuit includes a receiving coil. L s Secondary-side compensation network, rectifier unit and load resistor R ; The secondary-side compensation network includes a secondary-side compensation inductor. L s0 Secondary side compensation capacitor C s and C s0 ; The transmitting coil L p2 With receiving coil L s Energy is transferred from the transmitter to the receiver via magnetic field coupling, wherein the receiving coil L s The secondary-side compensation network is connected, which in turn is connected to the rectifier unit, which is connected to the load resistor. R； The rectifier unit includes four diodes. D 1. D 2. D 3. D 4 and capacitors C 0; The load resistor R One end is connected to the capacitor C One end of 0, diode D The negative terminal of 1 and the diode D Connect the negative terminal of 2; diode D The positive terminal of 1 is connected to the diode. D 3. Negative and secondary side compensation capacitors C s0 One end and secondary compensation inductor L s0 One end is connected; The load resistor R The other end is connected to the capacitor. C The other end of 0, diode D 3's positive terminal and diode D 4 is connected to the positive terminal; The diode D The positive terminals of 2 are respectively connected to the diode. D 4's negative terminal and receiving coil L s1 One end is connected; The receiving coil L s The other end is connected to the secondary compensation capacitor. C s One end is connected; Secondary side compensation capacitor C s The other end is connected to the secondary compensation capacitor. C s0 The other end and the secondary compensation inductor L s0 The other end is connected.

3. A parameter design method for a wireless charging system suitable for zero-phase-angle constant current and constant voltage based on any one of claims 1 and 2, characterized in that: The parameter design method specifically includes the following steps: Step 1: Construct a topology that simultaneously exhibits constant current / constant voltage output characteristics under varying coupling coefficients; Step 2: When the topology has constant current output characteristics, the transmitting coil L p2 Primary-side compensating inductor L p1 Primary-side compensation capacitor C p11 , C p12 and C p2 Secondary receiving coil L s Secondary compensation inductor L s0 Secondary side compensation capacitor C s and C s0 The relationship model that is satisfied is: in, This is the angular frequency corresponding to the constant current mode. j It is the symbol for imaginary numbers; Step 3: When the topology has constant voltage output characteristics, the primary-side compensation inductor... L p1 Primary-side compensation capacitor C p11 and C p12 Secondary receiving coil L s Secondary compensation inductor L s0 Secondary side compensation capacitor C s and C s0 The relationship model that is satisfied is: in, This is the angular frequency corresponding to the constant voltage mode; Step 4: Based on the solution of the relationship model in Steps 2 and 3, obtain the operating angular frequencies of the system when operating in constant current and constant voltage modes respectively: in: This is the ratio of the primary-side capacitance. , ; Step 5: Compensate for inductance L p0 and compensation capacitor C p0 The series topology compensates for the primary side, achieving zero-phase output in constant current mode, with the transmitting coil... L p2 Primary-side compensating inductor L p1 Primary-side compensation capacitor C p2 Compensating inductance L p0 and compensation capacitor C p0 The relational model is as follows: Step 6: The compensation inductor can be obtained based on the solution in Step 5. L p0 Compensation capacitor C p0 Relational model: 。 4. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method of claim 3.

5. A computer-readable storage medium for storing computer instructions, characterized in that, When the computer instructions are executed by the processor, they implement the steps of the method of claim 3.

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