A low-cost single-input adjustable multi-output WPT system and its control method

Abstract

The present invention relates to the technical field of magnetically coupled wireless power transmission, and specifically discloses a low-cost single-input adjustable multi-output WPT system and a control method thereof, wherein the system is provided with a positive half-wave rectifier circuit, a negative half-wave rectifier circuit, and a full-wave rectifier circuit at a secondary side receiving end, and a primary side controller and a secondary side controller are provided, thereby adopting positive and negative half-wave rectification and synchronous rectification to realize multi-channel output, and each output channel can be controlled to meet various charging requirements. In addition, the system and the control method utilize inherent half-wave rectification channels (positive half-wave rectifier circuit, negative half-wave rectifier circuit) to detect synchronization signals instead of using additional detection circuits, thereby realizing a compact and cost-saving system.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetically coupled wireless power transmission, and in particular to a low-cost single-input adjustable multiple-output WPT system and a control method thereof. Background Art

[0002] Wireless power transfer (WPT) is a practical technology that facilitates a wide range of applications, including smartphones and electric vehicles (EVs). Single-input, single-output (SISO) WPT systems have been widely researched due to their simplicity. In this digital age, electrical appliances are becoming increasingly complex. Traditional SISO WPT struggles to meet the requirements of multi-output charging targets. Consequently, the industry is calling for emerging wireless chargers equipped with multiple outputs.

[0003] To achieve multiple outputs, one approach is to increase the number of transmission paths by using a Multiple Input Multiple Output (MIMO) system. This means implementing multiple charging paths, involving a large number of transmitting and receiving devices.

[0004] To save costs, simplify the structure, and reduce the cross-coupling caused by MIMO systems, single-input, multiple-output (SIMO) WPT systems are currently more popular. One method of achieving this is through a single- or dual-T resonant circuit, which can be configured with passive components such as inductors and capacitors to achieve voltage or current conversion. However, this passive topology makes it difficult to adjust the output voltage or current during the charging process. Therefore, some scholars have adopted a DC-DC converter. Although DC-DC converters meet different charging requirements and have different outputs, they are still bulky and require more additional installation space. Summary of the Invention

[0005] The present invention provides a low-cost single-input adjustable multi-output WPT system and a control method thereof, which solves the technical problem of how to adjust the multi-channel output voltage during the charging process using a simple circuit.

[0006] To solve the above technical problems, the present invention provides a low-cost single-input adjustable multi-output WPT system, comprising:

[0007] The primary side transmitter is equipped with a high-frequency inverter and a primary side controller;

[0008] The secondary side receiving end is provided with a receiving coil circuit and a positive half-wave rectifier circuit, a negative half-wave rectifier circuit, and a full-wave rectifier circuit connected in parallel at both ends of the receiving coil circuit, and is also provided with a secondary side controller;

[0009] The secondary side controller is used to collect the output voltage V of the positive half-wave rectifier circuit c And according to V c With its reference voltage V crefThe error between them generates the corresponding PWM C control signal which acts on the positive half-wave rectifier circuit to adjust V c ;

[0010] The secondary side controller is also used to collect the output voltage V of the negative half-wave rectifier circuit b And according to V b With its reference voltage V bref The error between the two generates the corresponding PWM B control signal to act on the negative half-wave rectifier circuit to adjust V b ;

[0011] The primary side controller is used to collect the output voltage V of the full-wave rectifier circuit through the secondary side controller a And according to V a With its reference voltage V aref The error between the control of the high frequency inverter conduction angle δ to adjust V a .

[0012] Preferably, the positive half-wave rectifier circuit is provided with a diode D c 、PMOS tube Q c 、Load R c and filter capacitor C c , where the diode D c The positive terminal of the diode D is connected to the positive output terminal of the receiving coil circuit. c The negative terminal of the PMOS tube Q c The D pole of the PMOS tube Q c The S pole is connected to the load R c Then connect the negative output terminal of the receiving coil circuit, the PMOS tube Q c The G pole is connected to the secondary side controller, the filter capacitor C c In parallel with the load R c both ends of .

[0013] Preferably, the negative half-wave rectifier circuit is provided with a diode D b 、PMOS tube Q b 、Load R b and filter capacitor C b , where the diode D b The negative terminal of the diode D is connected to the positive output terminal of the receiving coil circuit. b The positive terminal of the PMOS tube Q b The S pole of the PMOS tube Q b The D pole is connected to the load R b Then connect the negative output terminal of the receiving coil circuit, the PMOS tube Q bThe G pole is connected to the secondary side controller, the filter capacitor C b In parallel with the load R b both ends of .

[0014] Preferably, the full-wave rectifier circuit is provided with a PMOS tube Q5, a PMOS tube Q6, a PMOS tube Q7, a PMOS tube Q8, a filter capacitor C d 、Load R a , wherein PMOS tube Q5, PMOS tube Q6, PMOS tube Q7, and PMOS tube Q8 are connected to form a full-bridge rectifier circuit, and the filter capacitor C d connected in parallel between the two output terminals of the full-bridge rectifier circuit, the load R a In parallel with the filter capacitor C d both ends of .

[0015] Preferably, the receiving coil circuit includes a receiving coil L S and its compensation capacitor C S .

[0016] Preferably, the secondary side controller is further configured to perform synchronous rectification, specifically comprising the steps of:

[0017] S1, set the conduction angle δ to δ0, the duty cycle D of the positive half-wave rectifier circuit Qc Set to D Qc0 , the duty cycle D of the positive half-wave rectifier circuit Qb Set to D Qb0 ;

[0018] S2. Determine the zero crossing point by shifting the time base of the PWM C control signal and the PWM B control signal;

[0019] S3. Provide a synchronous drive signal acting on the full-wave rectifier circuit according to the determined zero-crossing point, so that the primary-side controller is synchronized with the secondary-side controller.

[0020] Preferably, the step S2 specifically includes the steps of:

[0021] S21, initialization time T0, detection time sequence n=0;

[0022] S22, measure V at timing 0 c and V b And record it as V c0 and V b0 ;

[0023] S23, judge V c0 =V b0 =0 is true, if so, measure the V c and V b, and according to the subsequent timing V c and V b Determine the zero crossing point and go to step S3, if not, execute steps S24-S25;

[0024] S24, timing +1, measure V at timing 1 c and V b V c1 and V b1 ;

[0025] S25, judge V c1 >V c0 And V b1 >V b0 Is it true? If so, measure the V c and V b , and according to the subsequent timing V c and V b Determine the zero crossing point and go to step S3, if not, go to step S26;

[0026] S26, judge V c1 =V c0 >0 and V b1 =V b0 >0, if so, measure the V c and V b , and according to the subsequent timing V c and V b After determining the inverse zero-crossing point and shifting its phase by 180° to obtain the zero-crossing point, go to step S3. If not, go to step S27.

[0027] S27, measure the V of the subsequent timing c and V b , and according to the subsequent timing V c and V b After determining the anti-zero point and shifting its phase by 180° to obtain the zero point, the process proceeds to step S3.

[0028] Preferably, in step S23, the V c and V b Determine the zero crossing point, specifically:

[0029] Judge V c(n+1) =V cn 、V b(n+1) =V bn And V cn =V bn >0, if so, find the zero crossing point, where V cn and V bn Respectively represent V at time sequence n c and Vb , V c(n+1) and V b(n+1) Respectively represent V at timing n+1 c and V b ; If not, re-judge after timing +1;

[0030] In the step S25, the V c and V b Determine the zero crossing point, specifically:

[0031] Judge V c(n+1) =V cn And V b(n+1) =V bn Is it true? If so, find the zero-crossing point. If not, add 1 to the time sequence and re-judge.

[0032] In the step S26, the V c and V b Determine the inverse zero point, specifically:

[0033] Judge V c(n+1) =V cn =0 and V b(n+1) =V bn =0, if so, find the anti-zero point, if not, add 1 and re-judge;

[0034] In the step S27, the V c and V b Determine the inverse zero point, specifically:

[0035] Judge V c(n+1) =V cn =0 and V b(n+1) =V bn =0, if so, find the anti-zero point, if not, add 1 and re-judge.

[0036] The present invention also provides a low-cost control method for a single-input adjustable multi-output WPT system, comprising the steps of:

[0037] X1. Synchronizing the drive signals of the high-frequency inverter and the full-wave rectifier circuit;

[0038] X2, start charging; during the charging process, collect the output voltage V of the positive half-wave rectifier circuit c And according to V c With its reference voltage V cref The error between them generates the corresponding PWM C control signal which acts on the positive half-wave rectifier circuit to adjust V c ; Collect the output voltage V of the negative half-wave rectifier circuitb And according to V b With its reference voltage V bref The error between the two generates the corresponding PWM B control signal to act on the negative half-wave rectifier circuit to adjust V b ; Collect the output voltage V of the full-wave rectifier circuit a And according to V a With its reference voltage V aref The error between the control of the high frequency inverter conduction angle δ to adjust V a .

[0039] Furthermore, the step X1 specifically includes steps S1 to S3 as described in the system.

[0040] The present invention provides a low-cost, single-input, adjustable, multi-output WPT system and control method. This system incorporates positive, negative, and full-wave rectifier circuits at the secondary receiving end, along with primary and secondary controllers. This system utilizes positive and negative half-wave rectification and synchronous rectification to achieve multiple outputs, with each output channel being controllable to meet various charging requirements. Furthermore, this system and control method utilize inherent half-wave rectification channels (positive and negative half-wave rectification circuits) to detect synchronization signals, rather than requiring additional detection circuitry. This results in a compact and cost-effective system. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a topology diagram of a low-cost single-input adjustable multi-output WPT system provided in Example 1 of the present invention;

[0042] Figure 2 1 is an equivalent circuit diagram of (a) Ring #C and (b) Ring #B provided in Example 1 of the present invention;

[0043] Figure 3 This is a flowchart of synchronization signal detection and system charging provided by Example 1 of the present invention;

[0044] Figure 4 The synchronization signal detection i provided by embodiment 1 of the present invention S , drive signal (PWM C, PWM B), V c 、V b Change diagram: (a) state (a), (b) state (b), (c) state (c), (d) state (d), (e) state at the end of synchronization signal detection, (f) state at the end of synchronization signal detection experiment;

[0045] Figure 5 This is a schematic diagram of zero phase angle verification provided by Example 1 of the present invention;

[0046] Figure 6 This is a dynamic response diagram provided by Example 1 of the present invention: (a) R a From 10Ω to 30Ω and back to 10Ω, (b) R b From 20Ω to 30Ω and back to 20Ω, (c) R c From 20Ω to 30Ω and back to 20Ω;

[0047] Figure 7 This is a waveform diagram of the dynamic response of the system provided in Example 1 of the present invention to an input disturbance. DETAILED DESCRIPTION

[0048] The following describes the embodiments of the present invention in detail with reference to the accompanying drawings. The embodiments are provided for illustrative purposes only and are not to be construed as limiting the present invention. The accompanying drawings are provided for reference and illustration only and do not constitute a limitation on the scope of protection of the present invention. Many changes may be made to the present invention without departing from the spirit and scope of the present invention.

[0049] Example 1

[0050] In order to overcome the technical problems existing in the background technology and realize the adjustment of multiple output voltages during the charging process using a simple circuit, the embodiment of the present invention provides a low-cost single-input adjustable multi-output WPT system. The circuit topology of the system is as follows: Figure 1 Shown, including:

[0051] The primary transmitting end is equipped with a DC power supply V dc , high-frequency inverter (composed of MOS tubes Q1, Q2, Q3, Q4), primary compensation network (composed of inductor L T , capacitor C T Composition, R T is the corresponding internal resistance) and the transmitting coil L P (R p is the corresponding internal resistance), and a primary side controller connected to the high frequency inverter is also provided.

[0052] The secondary receiving end is provided with a receiving coil circuit connected in sequence (including the receiving coil L S and its compensation capacitor C S , R S is the corresponding resistor of the circuit), a positive half-wave rectifier circuit, a negative half-wave rectifier circuit, a full-wave rectifier circuit, and a secondary side controller.

[0053] like Figure 1 As shown, the positive half-wave rectifier circuit is equipped with a diode D c 、PMOS tube Q c 、Load R c and filter capacitor C c , where diode D cThe positive terminal of the diode D is connected to the positive output terminal of the receiving coil circuit. c The negative terminal of the PMOS tube Q c The D pole of PMOS tube Q c The S pole is connected to the load R c Then connect the negative output terminal of the receiving coil circuit, PMOS tube Q c The G pole is connected to the secondary side controller, the filter capacitor C c Connect in parallel with the load R c both ends of .

[0054] The negative half-wave rectifier circuit is equipped with a diode D b 、PMOS tube Q b 、Load R b and filter capacitor C b , where diode D b The negative end of the diode D is connected to the positive output end of the receiving coil circuit. b The positive terminal of the PMOS tube Q b S pole, PMOS tube Q b The D pole is connected to the load R b Then connect the negative output terminal of the receiving coil circuit, PMOS tube Q b The G pole is connected to the secondary side controller, the filter capacitor C b Connect in parallel with the load R b both ends of .

[0055] The full-wave rectifier circuit is equipped with PMOS tube Q5, PMOS tube Q6, PMOS tube Q7, PMOS tube Q8, filter capacitor C d 、Load R a , where PMOS tubes Q5, Q6, Q7, and Q8 are connected to form a full-bridge rectifier circuit, and the filter capacitor C d Connected in parallel between the two output terminals of the full-bridge rectifier circuit, the load R a Connect in parallel to the filter capacitor C d both ends of .

[0056] The secondary side controller collects the output voltage V of the positive half-wave rectifier circuit c And according to V c With its reference voltage V cref The error between them generates the corresponding PWM C control signal to act on the positive half-wave rectifier circuit to adjust V c .

[0057] The secondary side controller collects the output voltage V of the negative half-wave rectifier circuit b And according to V b With its reference voltage V brefThe error between them generates the corresponding PWM B control signal to act on the negative half-wave rectifier circuit to adjust V b .

[0058] The primary side controller collects the output voltage V of the full-wave rectifier circuit through the secondary side controller a And according to V a With its reference voltage V aref The error between the two controls the conduction angle δ of the high-frequency inverter to adjust V a .

[0059] like Figure 1 As shown, the primary side controller and the secondary side controller are provided with corresponding voltage divider circuits for voltage acquisition, and the PI controller generates the corresponding PWM control signal, etc., and information is transmitted between the primary and secondary sides through a wireless communication transmitter and receiver.

[0060] from Figure 1 The control logic of the system can be obtained from . There are two system controllers, namely the primary side controller and the secondary side controller. In addition, there are three closed control loops in the proposed system, including an outer loop (loop #A, corresponding to the full-wave rectifier circuit) and two inner loops (loop #B and loop #C, corresponding to the positive half-wave rectifier circuit and the negative half-wave rectifier circuit respectively). Loop #A will affect the output bus voltage (U S ). Loop #B and loop #C are inner loops and are independent of each other. For the outer control loop #A, the secondary side controller uses the A / D module to control the output voltage V after the voltage divider. a The primary side controller obtains V a And V a With reference V aref The error between the two is sent to the proportional integral controller (PI controller), and then the processed result is passed to the PSM controller to calculate the conduction angle δ to adjust the voltage V of loop #A a .

[0061] For loops #B and #C, the secondary side controller uses the A / D module after the voltage divider to measure the output voltage V b and V c Sampling is performed and the error information (V b and V bref , V c and V cref ) are sent to their PI controllers respectively, and then controlled by D Qb and D Qc To adjust the voltage V b and V c , D Qc is the positive half cycle duty cycle of PWM C (i.e. Q c driving signal), D Qbis the duty cycle of the negative half cycle of PWM B (i.e. Q b driving signal). Figure 2 (a) and (b) are the equivalent circuits of loops #C and #B.

[0062] For output channel #A, according to the relationship between input and output voltage, V a It can be expressed as:

[0063]

[0064] Among them U S is the bus voltage. The output voltage of channel C can be expressed as:

[0065]

[0066] Where ω represents the operating angular frequency of the system. Similarly, the output voltage of channel #B can be expressed as:

[0067]

[0068] Since the main controller and the sub-controller are not synchronized, they need to be synchronized before formal charging. The flowchart of synchronization signal detection and system charging is as follows: Figure 3 As shown. Before normal charging, the synchronization signal should be detected first. After finding the zero crossing point, the synchronization drive signals PWM 5, PWM 6, PWM 7, and PWM 8 can be given. The system enters the normal charging stage. V a 、V b 、V c By controlling δ, D Qb and D Qc To adjust.

[0069] More specifically, Figure 3 As shown, synchronous rectification specifically includes the following steps:

[0070] S1, set the conduction angle δ to δ0, the duty cycle D of the positive half-wave rectifier circuit Qc Set to D Qc0 , the duty cycle D of the positive half-wave rectifier circuit Qb Set to D Qb0 (Initialize the system by transferring a small amount of energy to the secondary side receiver for synchronization signal detection);

[0071] S2, determining the zero-crossing point by shifting the time base of the PWM C control signal and the PWM B control signal; specifically comprising the steps of:

[0072] S21, initialization time T0 (since the main controller and the sub-controller are not synchronized, the initial reference time T0 of PWM C and PWM B is random), detection timing n=0;

[0073] S22, measure V at timing 0 c and V b And record it as V c0 and V b0 ;

[0074] S23, judge V c0 =V b0 = 0 is established, if so (corresponding Figure 4 In the state (a)), the V c and V b , and according to the subsequent timing V c and V b Determine the zero crossing point (ZCP) and go to step S3, if not, execute steps S24-S25;

[0075] S24, timing +1, measure V at timing 1 c and V b V c1 and V b1 ;

[0076] S25, judge V c1 >V c0 And V b1 >V b0 Is it established? If so (corresponding to Figure 4 In the state (b)) the V c and V b , and according to the subsequent timing V c and V b Determine the zero crossing point (ZCP) and go to step S3, if not, go to step S26;

[0077] S26, judge V c1 =V c0 >0 and V b1 =V b0 >0 is established, if so (corresponding Figure 4 In the state (c)) the V c and V b , and according to the subsequent timing V c and V b Determine the anti-zero point (Anti-ZCP) and shift its phase by 180° to get the zero point and then go to step S3. If not (corresponding to Figure 4 If the state (d) is in step S27, the process is executed;

[0078] S27, measure the V of the subsequent timing c and V b , and according to the subsequent timing V c and V bDetermine the anti-zero crossing point (Anti-ZCP) and shift its phase by 180° to obtain the zero crossing point, and then proceed to step S3;

[0079] S3. A synchronous driving signal is provided to the full-wave rectifier circuit according to the determined zero-crossing point, so that the primary-side controller and the secondary-side controller are synchronized.

[0080] In step S23, according to the subsequent timing V c and V b Determine the zero crossing point, specifically:

[0081] Judge V c(n+1) =V cn 、V b(n+1) =V bn And V cn =V bn >0, if so, find the zero crossing point, where V cn and V bn Respectively represent V at time sequence n c and V b , V c(n+1) and V b(n+1) Respectively represent V at timing n+1 c and V b ; If not, re-judge after timing +1;

[0082] In step S25, according to the subsequent timing V c and V b Determine the zero crossing point, specifically:

[0083] Judge V c(n+1) =V cn And V b(n+1) =V bn Is it true? If so, find the zero-crossing point. If not, add 1 to the time sequence and re-judge.

[0084] In step S26, according to the subsequent timing V c and V b Determine the inverse zero point, specifically:

[0085] Judge V c(n+1) =V cn =0 and V b(n+1) =V bn =0, if so, find the anti-zero point, if not, add 1 and re-judge;

[0086] In step S27, according to the subsequent timing V c and V b Determine the inverse zero point, specifically:

[0087] Judge V c(n+1) =Vcn =0 and V b(n+1) =V bn =0, if so, find the anti-zero point, if not, add 1 and re-judge.

[0088] This example finds the zero crossing point by shifting the time base of PWM C and PWM B. The final state after synchronization is as follows Figure 4 (e) As shown. The final state of the synchronization signal detection in the experiment is as follows Figure 4 As shown in (f), we can see that Figure 4 (e) Highly consistent.

[0089] In order to verify the feasibility of the SIRMO WPT system proposed in this example, this example compares Figure 1 An experimental prototype was made and the system parameters are shown in Table 1.

[0090] Table 1 System parameters

[0091]

[0092] like Figure 5 The output voltage and current of the inverter are shown as follows ( in and i in ) and three channels (V a ,V b ,V c ) of the DC voltage output. It can be seen that u in and i in are in the same phase, which means the inverter can achieve ZPA.

[0093] Figure 6 (a), (b) and (c) are the loads R of the outer ring #A and the inner rings #B and #C respectively a 、R b and R c The output voltage dynamic response waveform when the load changes. Figure 6 (a) It can be seen that the load R of the outer ring #A a The change of not only affects itself, but also affects the two inner rings (#B and #C); it shows that R a From 10Ω to 30Ω and then back to 10Ω; all voltages can be controlled to reference values, namely 48V, 30V and 24V. Figure 6 (b) It can be seen that the load R of the inner ring #B b Changes in R affect only itself; it shows that R b From 20Ω to 30Ω, and then back to 20Ω; its own voltage V b Can be maintained at 30V with a small overshoot / undershoot; V a and V cThere is almost no change. Figure 6 (c) It can be seen that the load R of the inner ring #C c Changes in R affect only itself; it shows that R c Changing from 20Ω to 30Ω and then back to 20Ω again; the voltage V c Can be maintained at 24V with a small over / undershoot; V a and V b There is almost no change.

[0094] Figure 7 The input disturbance rejection response of the system is described. The input voltage varies from 80V to 70V and then back to 80V. Due to the control strategy, the proposed system can maintain three voltages of 48V, 30V, and 24V respectively.

[0095] In summary, the system is equipped with a positive half-wave rectifier circuit, a negative half-wave rectifier circuit, and a full-wave rectifier circuit at the secondary side receiving end, and a primary side controller and a secondary side controller are set, so as to adopt positive and negative half-wave rectification and synchronous rectification to achieve multi-channel output, and each output channel can be controlled to meet various charging requirements. In addition, the system and control method use the inherent half-wave rectification channel (positive half-wave rectifier circuit, negative half-wave rectifier circuit) to detect the synchronization signal instead of using an additional detection circuit, thereby realizing a compact and cost-saving system. The laboratory prototype achieves output of three voltage levels of 48V, 30V, and 24V, and the experimental results are highly consistent with the theoretical analysis. With the help of control logic, the system shows excellent robustness to different situations such as load changes and input disturbances.

[0096] Example 2

[0097] This embodiment provides a low-cost control method for a single-input adjustable multi-output WPT system, which is applied to the single-input adjustable multi-output WPT system of Example 1 (including or excluding the primary-side controller and the secondary-side controller). The control method specifically includes the following steps:

[0098] X1. Synchronize the drive signals of the high-frequency inverter and the full-wave rectifier circuit;

[0099] X2, start charging; during the charging process, collect the output voltage V of the positive half-wave rectifier circuit c And according to V c With its reference voltage V cref The error between them generates the corresponding PWM C control signal to act on the positive half-wave rectifier circuit to adjust V c ; Collect the output voltage V of the negative half-wave rectifier circuit b And according to V b With its reference voltage V brefThe error between them generates the corresponding PWM B control signal to act on the negative half-wave rectifier circuit to adjust V b ; Collect the output voltage V of the full-wave rectifier circuit a And according to V a With its reference voltage V aref The error between the two controls the conduction angle δ of the high-frequency inverter to adjust V a .

[0100] Step X1 specifically includes steps S1 to S3 of Example 1.

[0101] This control method focuses on protecting the process of using positive and negative half-wave rectification and synchronous rectification to achieve multi-channel output and individually control each output channel.

[0102] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A low-cost single-input adjustable multiple-output WPT system, characterized in that: include: The primary transmitting end is provided with a high-frequency inverter and a primary controller; The secondary side receiving end is provided with a receiving coil circuit and a positive half-wave rectifier circuit, a negative half-wave rectifier circuit, and a full-wave rectifier circuit connected in parallel at both ends of the receiving coil circuit, and is also provided with a secondary side controller; The secondary side controller is used to collect the output voltage of the positive half-wave rectifier circuit V c And according to V c With its reference voltage V cref The error between the two generates a corresponding PWM C control signal which acts on the positive half-wave rectifier circuit to adjust V c ; The secondary side controller is also used to collect the output voltage of the negative half-wave rectifier circuit V b And according to V b With its reference voltage V bref The error between the two generates the corresponding PWM B control signal which acts on the negative half-wave rectifier circuit to adjust V b ; The primary side controller is used to collect the output voltage of the full-wave rectifier circuit through the secondary side controller V a And according to V a With its reference voltage V aref The error between controls the conduction angle of the high frequency inverter δ , to adjust V a .

2. A low-cost single-input adjustable multiple-output WPT system according to claim 1, characterized in that: The positive half-wave rectifier circuit is provided with a diode D c 、PMOS tube Q c ,load R c and filter capacitors C c , where the diode D c The positive terminal of the diode is connected to the positive output terminal of the receiving coil circuit. D c The negative terminal of the PMOS tube is connected Q c The D pole of the PMOS tube Q c The S pole is connected to the load R c Then connected to the negative output terminal of the receiving coil circuit, the PMOS tube Q c The G pole is connected to the secondary side controller, the filter capacitor C c Connect in parallel to the load R c both ends of .

3. A low-cost single-input adjustable multiple-output WPT system according to claim 1, characterized in that: The negative half-wave rectifier circuit is provided with a diode D b 、PMOS tube Q b ,load R b and filter capacitors C b , where the diode D b The negative terminal of the diode is connected to the positive output terminal of the receiving coil circuit. D b The positive terminal of the PMOS tube is connected Q b The S pole of the PMOS tube Q b The D pole is connected to the load R b Then connected to the negative output terminal of the receiving coil circuit, the PMOS tube Q b The G pole is connected to the secondary side controller, the filter capacitor C b Connect in parallel to the load R b both ends of .

4. A low-cost single-input adjustable multiple-output WPT system according to claim 1, characterized in that: The full-wave rectifier circuit is provided with a PMOS tube Q 5. PMOS tube Q 6. PMOS tube Q 7. PMOS tube Q 8. Filter capacitor C d ,load R a , where PMOS tube Q 5. PMOS tube Q 6. PMOS tube Q 7. PMOS tube Q 8 are connected into a full-bridge rectifier circuit, the filter capacitor C d connected in parallel between the two output ends of the full-bridge rectifier circuit, the load R a In parallel with the filter capacitor C d both ends of .

5. A low-cost single-input adjustable multiple-output WPT system according to claim 1, characterized in that: The receiving coil circuit includes a receiving coil L S And its compensation capacitor C S .

6. A low-cost single-input adjustable multiple-output WPT system according to claim 1, characterized in that: The secondary side controller is also used to perform synchronous rectification, which specifically includes the steps of: S1, the conduction angle δ Set to δ 0, the duty cycle of the positive half-wave rectifier circuit D Qc Set to D Qc0 , the duty cycle of the negative half-wave rectifier circuit D Qb Set to D Qb0 ; S2, determining the zero crossing point by moving the time base of the PWM C control signal and the PWM B control signal; S3. According to the determined zero-crossing point, a synchronous driving signal is provided to act on the full-wave rectifier circuit, so that the primary-side controller is synchronized with the secondary-side controller.

7. A low-cost single-input adjustable multiple-output WPT system according to claim 6, characterized in that: The step S2 specifically includes the following steps: S21, initialization time T 0, detection timing n=0; S22, measurement sequence 0 V c and V b And record it as V c0 and V b0 ; S23. Judgment V c0 = V b0 =0 is true, if so, measure the subsequent timing V c and V b , and according to the subsequent timing V c and V b Determine the zero crossing point and go to step S3, if not, go to steps S24-S25; S24, timing +1, measure the timing 1 at this time V c and V b Recorded as V c1 and V b1 ; S25. Judgment V c1 > V c0 and V b1 > V b0 Is it true? If so, measure the subsequent timing V c and V b , and according to the subsequent timing V c and V b Determine the zero crossing point and go to step S3, if not, go to step S26; S26. Judgment V c1 = V c0 >0 and V b1 = V b0 >0 is true, if so, measure the subsequent timing V c and V b , and according to the subsequent timing V c and V b After determining the reverse zero-crossing point and shifting its phase by 180° to obtain the zero-crossing point, go to step S3, if not, go to step S27; S27, measure the subsequent timing V c and V b , and according to the subsequent timing V c and V b After determining the reverse zero-crossing point and shifting its phase by 180° to obtain the zero-crossing point, the process proceeds to step S3.

8. A low-cost single-input adjustable multiple-output WPT system according to claim 7, characterized in that: In step S23, the subsequent timing is V c and V b Determine the zero crossing point, specifically: judge V c(n+1) = V cn , V b(n+1) = V bn and V cn = V bn >0, if so, find the zero crossing point, where V cn and V bn Respectively represent the time series n V c and V b , V c(n+1) and V b(n+1) They represent the time sequence n+1 respectively. V c and V b ; If not, re-judge after timing +1; In step S25, the subsequent timing is V c and V b Determine the zero crossing point, specifically: judge V c(n+1) = V cn and V b(n+1) = V bn Is it true? If so, find the zero-crossing point. If not, add 1 to the timing and judge again. In step S26, the subsequent timing is V c and V b Determine the anti-zero point, specifically: judge V c(n+1) = V cn =0 and V b(n+1) = V bn =0, if yes, find the anti-zero point, if not, re-judge after adding 1 to the timing sequence; In step S27, the subsequent timing is V c and V b Determine the anti-zero point, specifically: judge V c(n+1) = V cn =0 and V b(n+1) = V bn =0, if yes, find the anti-zero point, if not, re-judge after adding 1 to the timing.

9. A control method for a low-cost single-input adjustable multi-output WPT system as described in any one of claims 1 to 5, characterized in that: Includes steps: X1. Synchronizing the driving signals of the high-frequency inverter and the full-wave rectifier circuit; X2, start charging; during the charging process, collect the output voltage of the positive half-wave rectifier circuit V c And according to V c With its reference voltage V cref The error between the two generates a corresponding PWM C control signal which acts on the positive half-wave rectifier circuit to adjust V c ; Collect the output voltage of the negative half-wave rectifier circuit V b And according to V b With its reference voltage V bref The error between the two generates the corresponding PWM B control signal which acts on the negative half-wave rectifier circuit to adjust V b ; Collect the output voltage of the full-wave rectifier circuit V a And according to V a With its reference voltage V aref The error between controls the conduction angle of the high frequency inverter δ , to adjust V a .

10. A low-cost single-input adjustable multi-output WPT system control method according to claim 9, characterized in that: The step X1 specifically includes steps S1 to S3 as described in any one of claims 6 to 8.

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