A secondary side resonant adaptive controllable rectifier for wireless charging

Abstract

The invention discloses a secondary-side resonant adaptive controllable rectifier converter for wireless charging, comprising a primary side section, a secondary side section, and a control module. The primary side section includes a full-bridge inverter, the input of which is connected to a DC voltage source U. DC LCC compensation network, including filter inductor L f1 Parallel compensation capacitor C f A series compensation capacitor C1 is connected between the full-bridge inverter and the magnetic coupler; the primary winding L1 is connected between the compensation capacitor C1 and the full-bridge inverter. The secondary side includes an energy storage capacitor C... L The system comprises a secondary coil L2 and a totem-pole bridgeless rectifier converter; a control module connected to the secondary side; and a magnetic coupler formed by the primary coil L1 and the secondary coil L2. This invention maintains fast phase tracking capability and good stability, thus providing an accurate phase reference for the current loop, improving the overall dynamic performance of the system. It can correct the voltage and current of the secondary coil to be in phase, thereby achieving resonant adaptive operation and increasing the system output power.

Description

Technical Field

[0001] This invention belongs to the field of power electronics and wireless energy transmission technology, specifically relating to a secondary-side resonant adaptive controllable rectifier converter for wireless charging. Background Technology

[0002] With the rapid development of the electric vehicle industry, wireless charging technology has gradually become an important development direction for electric vehicle charging due to its advantages such as no physical contact, convenient operation, and high safety. However, in existing wireless charging systems for electric vehicles, there are resonant frequency detuning problems caused by the relative positions of the primary and secondary coils, load changes, and component parameter drift. Summary of the Invention

[0003] In view of the above-mentioned shortcomings and defects of the prior art, the purpose of this invention is to provide a secondary resonant adaptive controllable rectifier converter for wireless charging, which solves the problem of resonant frequency detuning that easily occurs in the existing wireless charging system for electric vehicles.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a secondary resonant adaptive controllable rectifier converter for wireless charging, comprising a primary side part, a secondary side part, and a control module.

[0005] The primary side includes a full-bridge inverter, the input of which is connected to a DC voltage source U. DC .

[0006] It also includes an LCC compensation network, which contains a filter inductor L f1 A parallel compensation capacitor C f A series compensation capacitor C1, the LCC compensation network is connected between the full-bridge inverter and the magnetic coupler.

[0007] It also includes a primary winding L1, which is connected between the compensation capacitor C1 and the full-bridge inverter.

[0008] The secondary side includes an energy storage capacitor C. L Secondary coil L2 and totem pole bridgeless rectifier converter.

[0009] The control module is connected to the secondary side.

[0010] The primary coil L1 and the secondary coil L2 constitute a magnetic coupler.

[0011] The present invention also has the following technical features:

[0012] The full-bridge inverter includes MOSFET switches S1, S2, S3, and S4.

[0013] The drains of MOSFET switch S1 and MOSFET switch S2 are connected to a DC voltage source U. DC The positive terminal, the source of MOSFET switch S3, and the source of MOSFET switch S4 are connected to the DC voltage source U. DC The negative electrode.

[0014] The source of MOSFET switch S1 is connected to the drain of MOSFET switch S3, and the source of MOSFET switch S2 is connected to the drain of MOSFET switch S4.

[0015] The filter inductor L f1 One end is connected to a series compensation capacitor C1, and the filter inductor L f1 The other end is connected to the source of the MOSFET switch S1.

[0016] The parallel compensation capacitor C f One end is connected to the filter inductor L f1 Connect one end of the series compensation capacitor C1, and connect the parallel compensation capacitor C f The other end is connected to the source of the MOSFET switch S2.

[0017] The series compensation capacitor C1 is connected to the filter inductor L f1 One end of the transistor is connected to one end of L1, and the other end of L1 is connected to the source of the MOSFET switch S4.

[0018] The secondary coil L2 is connected to a totem-pole bridgeless rectifier converter, and the totem-pole bridgeless rectifier converter is connected to an energy storage capacitor C. L The load is connected in parallel to the energy storage capacitor C. L superior.

[0019] The totem pole bridgeless rectifier converter includes MOSFET switch S5, MOSFET switch S6, MOSFET switch S7 and MOSFET switch S8.

[0020] The drains of MOSFET switch S5 and MOSFET switch S7 are connected to the energy storage capacitor C. L At one end, the source of MOSFET switch S6 and the source of MOSFET switch S8 are connected to the energy storage capacitor C. L The other end.

[0021] The source of MOSFET switch S5 is connected to the drain of MOSFET switch S6, and the source of MOSFET switch S7 is connected to the drain of MOSFET switch S8.

[0022] One end of the secondary coil L2 is connected to the source of the MOSFET switch S5, and the other end of the secondary coil L2 is connected to the source of the MOSFET switch S7.

[0023] The control module includes: A secondary current sampling module is used to acquire the current I of the secondary coil L2. L2 .

[0024] The secondary coil voltage sampling module and the load voltage sampling module are used to acquire the voltage V of the secondary coil L2, respectively. L2 and load voltage V RL .

[0025] Frequency-locked loop, used to obtain voltage V L2 The phase and frequency.

[0026] Current loop PI controller and voltage loop PI controller are used for closed-loop compensation and correction.

[0027] A PWM modulation unit is used to output drive signals for MOSFET switches S5, S6, S7 and S8.

[0028] A MOS driver module is used to control the on and off of MOSFET switches S5, S6, S7 and S8.

[0029] The control module adopts a dual closed-loop control architecture of voltage outer loop and current inner loop, specifically including: The outer voltage loop is based on the load voltage V. RL As a feedback signal, a closed-loop regulation mechanism is used to stabilize the output voltage at a preset DC reference voltage U. ref And output I through voltage loop PI controller p .

[0030] Frequency-locked loop obtains voltage V L2 Phase and frequency and output The voltage V in the secondary coil L2 L2 When frequency fluctuations occur, it continuously provides a precise phase reference for the inner current loop.

[0031] The inner current loop uses the secondary coil L2 current I L2 As a feedback signal, its reference current I ref It consists of two parts—the output I of the voltage loop. p With frequency-locked loop output .

[0032] After compensation and correction by the current loop PI controller, the current loop outputs the duty cycle signal d to the PWM modulation unit. Finally, the PWM modulation unit generates the corresponding drive signal to control the switching transistors in the totem pole bridgeless rectifier converter to turn on and off according to the preset mode to achieve the resonant adaptive function and improve the system output power.

[0033] Compared with the prior art, the beneficial technical effects of this invention are: (I) The device of the present invention, by setting a totem pole bridgeless rectifier converter, can maintain fast phase tracking capability and good stability, thereby providing an accurate phase reference for the current loop, improving the overall dynamic performance of the system, correcting the voltage and current of the secondary coil to make them in phase, thereby achieving resonance self-adaptation and improving the system output power.

[0034] (II) The present invention introduces an active control strategy based on totem pole bridgeless topology and dual closed-loop control in the secondary rectification stage, which automatically tracks and adapts to the resonance state of the secondary circuit, so that the secondary coil current always keeps in phase with the voltage, realizes the resonance self-adaptation of the system in the full operating range, thereby maximizing energy transmission efficiency and output power, and improving the overall performance and robustness of the system. Attached Figure Description

[0035] Figure 1 This is a circuit diagram of the secondary-side resonant adaptive controllable rectifier converter for wireless charging according to the present invention.

[0036] Figure 2 This is the equivalent circuit diagram of the secondary-side resonant adaptive controllable rectifier converter for wireless charging according to the present invention.

[0037] Figure 3 This is a circuit diagram of the secondary resonant adaptive controllable rectifier converter for wireless charging according to the present invention in mode 1.

[0038] Figure 4 This is a circuit diagram of the secondary-side resonant adaptive controllable rectifier converter for wireless charging according to the present invention in mode 2.

[0039] Figure 5 This is a circuit diagram of the secondary-side resonant adaptive controllable rectifier converter for wireless charging according to the present invention in mode 3.

[0040] Figure 6 This is a circuit diagram of the secondary resonant adaptive controllable rectifier converter for wireless charging of the present invention in mode 4.

[0041] Figure 7 The voltage V of the secondary-side resonant adaptive controllable rectifier converter for wireless charging of the present invention under normal operating conditions. L2 V RLWith current I L2 The waveform diagram.

[0042] The specific content of the present invention will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0043] It should be noted that, unless otherwise specified, all raw materials used in this invention are those known in the prior art.

[0044] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0045] Example 1: A secondary-side resonant adaptive controllable rectifier converter for wireless charging, such as Figures 1 to 5 As shown, it includes the primary side, the secondary side, and the control module.

[0046] The primary side includes a full-bridge inverter, the input of which is connected to a DC voltage source U. DC .

[0047] It also includes an LCC compensation network, which contains a filter inductor L f1 A parallel compensation capacitor C f A series compensation capacitor C1, the LCC compensation network is connected between the full-bridge inverter and the magnetic coupler.

[0048] It also includes a primary winding L1, which is connected between the compensation capacitor C1 and the full-bridge inverter.

[0049] The secondary side includes an energy storage capacitor C. L Secondary coil L2 and totem pole bridgeless rectifier converter.

[0050] The control module is connected to the secondary side.

[0051] The primary coil L1 and the secondary coil L2 constitute a magnetic coupler, with mutual inductance M and coupling coefficient k between them.

[0052] The full-bridge inverter generates AC power at a frequency of 85kHz. Energy storage capacitor C L It is connected in parallel with a load, which is a battery.

[0053] The primary side inverts DC power into high-frequency AC power, which is then transmitted through the LCC compensation network and the primary coil. The secondary side receives energy through the secondary coil, and the totem-pole bridgeless rectifier converter converts the AC power back to DC power to supply the load. The control module is based on a dual closed-loop control architecture of "voltage outer loop - current inner loop". It uses a frequency-locked loop to obtain the phase and frequency of the secondary coil voltage in real time, and uses this to generate a synchronization reference signal for the current inner loop. This signal controls the switching transistors of the totem-pole bridgeless rectifier converter, ensuring that the secondary coil current is always in phase with the voltage, thereby achieving adaptive tracking of the resonant frequency.

[0054] This invention effectively solves the system detuning problem caused by coupling changes, load fluctuations, or parameter drift, and can maintain efficient and high-power energy transmission across the entire operating range, thereby improving the dynamic performance and robustness of the wireless charging system.

[0055] As a preferred embodiment: The full-bridge inverter includes MOSFET switches S1, S2, S3, and S4.

[0056] The drains of MOSFET switch S1 and MOSFET switch S2 are connected to a DC voltage source U. DC The positive terminal, the source of MOSFET switch S3, and the source of MOSFET switch S4 are connected to the DC voltage source U. DC The negative electrode.

[0057] The source of MOSFET switch S1 is connected to the drain of MOSFET switch S3, and the source of MOSFET switch S2 is connected to the drain of MOSFET switch S4.

[0058] As a preferred embodiment: The filter inductor L f1 One end is connected to a series compensation capacitor C1, and the filter inductor L f1 The other end is connected to the source of the MOSFET switch S1.

[0059] The parallel compensation capacitor C f One end is connected to the filter inductor L f1 Connect one end of the series compensation capacitor C1, and connect the parallel compensation capacitor C f The other end is connected to the source of the MOSFET switch S2.

[0060] The series compensation capacitor C1 is connected to the filter inductor L f1 One end of the transistor is connected to one end of L1, and the other end of L1 is connected to the source of the MOSFET switch S4.

[0061] As a preferred embodiment: The secondary coil L2 is connected to a totem-pole bridgeless rectifier converter, and the totem-pole bridgeless rectifier converter is connected to an energy storage capacitor C. L The load is connected in parallel to the energy storage capacitor C. L superior.

[0062] The totem pole bridgeless rectifier converter includes MOSFET switch S5, MOSFET switch S6, MOSFET switch S7 and MOSFET switch S8.

[0063] The drains of MOSFET switch S5 and MOSFET switch S7 are connected to the energy storage capacitor C. L At one end, the source of MOSFET switch S6 and the source of MOSFET switch S8 are connected to the energy storage capacitor C. L The other end.

[0064] The source of MOSFET switch S5 is connected to the drain of MOSFET switch S6, and the source of MOSFET switch S7 is connected to the drain of MOSFET switch S8.

[0065] One end of the secondary coil L2 is connected to the source of the MOSFET switch S5, and the other end of the secondary coil L2 is connected to the source of the MOSFET switch S7.

[0066] In this embodiment: L f1 40uH, C f : 87.66nF, C1: 58.44nF, L1: 100uH, M: 30uH, L2: 100uH.

[0067] The totem-pole bridgeless rectifier converter has four operating modes: Mode 1 (e.g.) Figure 3 (As shown): S5 and S7 are off, S6 and S8 are on, there are two loops on the secondary side, and the voltage V of the secondary coil L2 is... L2 During the positive half-cycle, the secondary coil L2 of the inductor is charged through the circuit composed of S6 and S8, and the current I of the secondary coil L2 is... L2 Increase; simultaneously, the energy storage capacitor C L Discharge the load.

[0068] Mode 2 (e.g.) Figure 4 (As shown): S6 and S7 are off, S5 and S8 are on, and the voltage V of the secondary coil L2 is... L2 During the positive half-cycle, the secondary coil L2 outputs power to the load.

[0069] Mode 3 (e.g.) Figure 5(As shown): S6 and S8 are off, S5 and S7 are on, there are two loops on the secondary side, and the voltage V of the secondary coil L2 is... L2 During the negative half-cycle, the secondary coil L2 of the inductor is charged through the circuit composed of S5 and S7, and the current I of the secondary coil L2 is... L2 The reverse increase occurs; simultaneously, the energy storage capacitor C... L Discharge the load.

[0070] Mode 4 (e.g.) Figure 6 (As shown): S5 and S8 are off, S6 and S7 are on, and the voltage V of the secondary coil L2 is... L2 During the negative half-cycle, the secondary coil L2 outputs power to the load.

[0071] To suppress the peak current near the zero-crossing point, S7 and S8 are turned off simultaneously near the zero-crossing point of the secondary coil L2 voltage. At this time, the non-zero secondary coil L2 current will flow through the body diode of the MOSFET switch until the secondary coil L2 current decays to 0 and the diode is turned off. There is no connecting loop between the capacitor and the secondary coil inductor, thus avoiding the generation of peak current.

[0072] The totem-pole bridgeless rectifier converter operates in continuous conduction mode (CCM), meaning that the secondary coil L2 is periodically charged and discharged. During a switching cycle excluding the area near the zero crossing, there is always current flowing through the secondary coil L2, and the current is not zero.

[0073] The totem-pole bridgeless rectifier converter uses average current mode (ACM) control under CCM, that is, it collects the average value of the current as the feedback value and compares it with the reference signal to achieve resonance adaptation.

[0074] As a preferred embodiment: The control module includes: A secondary current sampling module is used to acquire the current I of the secondary coil L2. L2 .

[0075] The secondary coil voltage sampling module and the load voltage sampling module are used to acquire the voltage V of the secondary coil L2, respectively. L2 and load voltage V RL .

[0076] Frequency-locked loop, used to obtain voltage V L2 The phase and frequency.

[0077] Current loop PI controller and voltage loop PI controller are used for closed-loop compensation and correction.

[0078] A PWM modulation unit is used to output drive signals for MOSFET switches S5, S6, S7 and S8.

[0079] A MOS driver module is used to control the on and off of MOSFET switches S5, S6, S7 and S8.

[0080] As a preferred embodiment: The control module adopts a dual closed-loop control architecture of voltage outer loop and current inner loop, specifically including: The outer voltage loop is based on the load voltage V. RL As a feedback signal, a closed-loop regulation mechanism is used to stabilize the output voltage at a preset DC reference voltage U. ref And output I through voltage loop PI controller p .

[0081] Frequency-locked loop obtains voltage V L2 Phase and frequency and output The voltage V in the secondary coil L2 L2 When frequency fluctuations occur, it continuously provides a precise phase reference for the inner current loop.

[0082] The inner current loop uses the secondary coil L2 current I L2 As a feedback signal, its reference current I ref It consists of two parts—the output I of the voltage loop. p With frequency-locked loop output .

[0083] After compensation and correction by the current loop PI controller, the current loop outputs the duty cycle signal d to the PWM modulation unit. Finally, the PWM modulation unit generates the corresponding drive signal to control the switching transistors in the totem pole bridgeless rectifier converter to turn on and off according to the preset mode to achieve the resonant adaptive function and improve the system output power.

[0084] The voltage V of the totem-pole bridgeless rectifier converter under normal operating conditions L2 V RL With current I L2 The waveform diagram is as follows Figure 7 As shown, the system reaches a steady state after three cycles of adjustment, achieving phase co-existence of the secondary coil voltage and current, i.e., secondary resonance.

[0085] This invention combines a high-efficiency totem-pole bridgeless rectifier topology with an advanced digital control strategy, endowing the secondary-side rectifier with an intelligent "resonance adaptive" function. It not only improves efficiency by reducing device losses but also proactively responds to changes in system parameters, ensuring that the wireless charging system maintains a high-efficiency, high-power transmission state under various practical operating conditions, thereby enhancing the performance, robustness, and practicality of the entire charging system.

[0086] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions conceived by those skilled in the art within the scope of the technology disclosed in the present invention without creative effort are covered within the scope of protection of the present invention.

Claims

1. A secondary-side resonant adaptive controllable rectifier converter for wireless charging, characterized in that, It includes the primary side, the secondary side, and the control module; The primary side includes a full-bridge inverter, the input of which is connected to a DC voltage source U. DC ; It also includes an LCC compensation network, containing a filter inductor L f1 Parallel compensation capacitor C f A series compensation capacitor C1 is connected between the full-bridge inverter and the magnetic coupler; It also includes a primary winding L1, which is connected between the compensation capacitor C1 and the full-bridge inverter; The secondary side includes an energy storage capacitor C. L Secondary coil L2 and totem-pole bridgeless rectifier converter; The control module is connected to the secondary side section; The primary coil L1 and the secondary coil L2 constitute a magnetic coupler.

2. The secondary-side resonant adaptive controllable rectifier converter for wireless charging as described in claim 1, characterized in that, The full-bridge inverter includes MOSFET switches S1, S2, S3, and S4. The drains of MOSFET switch S1 and MOSFET switch S2 are connected to a DC voltage source U. DC The positive terminal, the source of MOSFET switch S3, and the source of MOSFET switch S4 are connected to the DC voltage source U. DC The negative electrode; The source of MOSFET switch S1 is connected to the drain of MOSFET switch S3, and the source of MOSFET switch S2 is connected to the drain of MOSFET switch S4.

3. The secondary-side resonant adaptive controllable rectifier converter for wireless charging as described in claim 2, characterized in that, The filter inductor L f1 One end is connected to a series compensation capacitor C1, and the filter inductor L f1 The other end is connected to the source of the MOSFET switch S1; The parallel compensation capacitor C f One end is connected to the filter inductor L f1 Connect one end of the series compensation capacitor C1, and connect the parallel compensation capacitor C f The other end is connected to the source of the MOSFET switch S2; The series compensation capacitor C1 is connected to the filter inductor L f1 One end of the transistor is connected to one end of L1, and the other end of L1 is connected to the source of the MOSFET switch S4.

4. The primary-side hybrid reconfigurable compensation system for wireless charging of electric vehicles as described in claim 3, characterized in that, The secondary coil L2 is connected to a totem-pole bridgeless rectifier converter, and the totem-pole bridgeless rectifier converter is connected to an energy storage capacitor C. L The load is connected in parallel to the energy storage capacitor C. L superior; The totem pole bridgeless rectifier converter includes MOSFET switch S5, MOSFET switch S6, MOSFET switch S7 and MOSFET switch S8; The drains of MOSFET switch S5 and MOSFET switch S7 are connected to the energy storage capacitor C. L At one end, the source of MOSFET switch S6 and the source of MOSFET switch S8 are connected to the energy storage capacitor C. L The other end; The source of MOSFET switch S5 is connected to the drain of MOSFET switch S6, and the source of MOSFET switch S7 is connected to the drain of MOSFET switch S8. One end of the secondary coil L2 is connected to the source of the MOSFET switch S5, and the other end of the secondary coil L2 is connected to the source of the MOSFET switch S7.

5. The secondary-side resonant adaptive controllable rectifier converter for wireless charging as described in claim 4, characterized in that, The control module includes: A secondary current sampling module is used to acquire the current I of the secondary coil L2. L2 ; The secondary coil voltage sampling module and the load voltage sampling module are used to acquire the voltage V of the secondary coil L2, respectively. L2 and load voltage V RL ; Frequency-locked loop, used to obtain voltage V L2 Phase and frequency; Current loop PI controller and voltage loop PI controller are used for closed-loop compensation and correction; A PWM modulation unit is used to output drive signals for MOSFET switches S5, S6, S7 and S8. A MOS driver module is used to control the on and off of MOSFET switches S5, S6, S7 and S8.

6. The secondary-side resonant adaptive controllable rectifier converter for wireless charging as described in claim 5, characterized in that, The control module adopts a dual closed-loop control architecture of voltage outer loop and current inner loop, specifically including: The outer voltage loop is based on the load voltage V. RL As a feedback signal, a closed-loop regulation mechanism is used to stabilize the output voltage at a preset DC reference voltage U. ref And output I through voltage loop PI controller p ; Frequency-locked loop obtains voltage V L2 Phase and frequency and output The voltage V in the secondary coil L2 L2 When frequency fluctuations occur, it continuously provides a precise phase reference for the inner current loop; The inner current loop uses the secondary coil L2 current I L2 As a feedback signal, its reference current I ref It consists of two parts—the output I of the voltage loop. p With frequency-locked loop output ; After compensation and correction by the current loop PI controller, the current loop outputs the duty cycle signal d to the PWM modulation unit. Finally, the PWM modulation unit generates the corresponding drive signal to control the switching transistors in the totem pole bridgeless rectifier converter to turn on and off according to the preset mode.

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