Wireless Charging Overload Protection Method

Abstract

The present invention discloses a method for wireless charging over - load protection, including a receiving process, a starting process, a charging voltage control process, an adapter control unit process, and a battery over - load protection process. It is characterized in that: The resonant inductor L1 receives the energy sent by the transmitting coil. C0 and L1 are in parallel resonance and then in series resonance with C0* to further boost the resonant voltage. After resonance, it is rectified by a rectifier bridge to convert the high - frequency changing magnetic energy into direct current, and R0 and R0* are used to limit this high voltage. In the circuit, D17 can prevent the high voltage from the back - end switching power supply from returning and forming a superposition when it is turned off, thus generating a higher voltage. D18 provides a voltage - current discharge circuit when the switch tube Q1 of the subsequent stage is turned off. The triple protection of the present invention is carried out simultaneously, and it notifies the background adapter that there is a short - circuit phenomenon, which needs to be processed, effectively reducing the losses to the device and the charging user during the charging process.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless charging, and specifically to a method for protecting against overloading in wireless charging. Background Art

[0002] In recent years, the core technology of wireless charging has become increasingly mature. The efficiency of wireless charging can already exceed 90%, and the wireless charging power can reach 30 kW. However, during the charging process established between in-vehicle devices and charging piles, due to overloading, battery damage, adapter damage, and even vehicle spontaneous combustion accidents may occur. The above drawbacks still remain problems faced by the wireless charging industry. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for protecting against overloading in wireless charging, which can achieve high-efficiency charging and avoid overloading.

[0004] To achieve the above object of the invention, the present invention is implemented by adopting the following technical solutions: A method for protecting against overloading in wireless charging, including a receiving process, a starting process, a charging voltage control process, an adapter control unit process, and an overloading protection process for the battery. The characteristics are as follows: The L1 resonant inductor receives the energy sent by the transmitting coil. C0 and L1 are in parallel resonance and then form a series resonance with C0* to further boost the resonant voltage. After resonance, it is rectified by a rectifier bridge to convert the high-frequency changing magnetic energy into direct current, and R0 and R0* are used to limit this high voltage. In the circuit, D17 can prevent the high voltage from the back-end switching power supply from returning and forming a superimposition when it is turned off, thus generating a higher voltage. D18 provides a voltage and current discharge loop when the Q1 switching transistor in the subsequent stage is turned off. The DC voltage output by D17, about 650V - 850V, passes through the FU 3A fuse and the T 5D11 thermistor starting resistor, is divided by two electrolytic capacitors C1 and C2550v120uf in series, and is loaded onto the drain of the Q1 MSFET P-channel regulating transistor through the switching transformer T1. The breakdown voltage of Q1 is 1200V 3A. Another path is loaded onto the 7th pin of the power switch chip UC3842E through the R3250k starting resistor. The UC3842 internally has an undervoltage lockout circuit, and the on and off thresholds are 16V and 10V respectively. R2 is a current sampling resistor. When the output load becomes too heavy due to some reason, the voltage on R2 increases. This voltage and the voltage-dividing circuit composed of R9 and R8 will cause the voltage on the 3rd pin of UC3842 to increase. After being processed inside the chip, the output PWM becomes narrower, thereby reducing the output.

[0005] The foregoing wireless charging overload protection method is characterized in that: when D7 and D15 are forward-conducting during the control process of the charging voltage, the charging voltage output and the voltage for the operation of the backend BMS are established; the DC 24V voltage output by D7 is filtered by the high-frequency filter C01 and the electrolytic capacitor C11 to generate the operating voltage; the first path is limited in current by R39 and R40 and applied to the positive electrode of the cooling fan, and the second path is applied to the base of Q3, and its control terminal obtains the conduction voltage, forming a switch connection to make the fan operate. The third path is applied to the collector of Q2, R31 is the upper bias resistor and the reference output of V2F is 5V operating voltage, R32 and R29 are voltage-divided to obtain a 2.5V reference voltage, and C04 is the noise elimination capacitor for the reference voltage; the fourth path is applied to R12, and the voltage division of R12 and R11 is controlled by the reference voltage of V1F. The increase or decrease in voltage caused by the change in the output load is controlled by the feedback of the PC817 optocoupler to adjust the PWM duty cycle output of the primary side so as to achieve the adjustment purpose; RT2 is close to D15, and the temperature of the temperature control thermistor RT2 gradually increases as time goes by after charging. The voltage change caused is output through UE1 BMS OUT3 to control PC817 to adjust the PWM output of the primary side to offset the influence brought by the temperature change; C18 and R50 are RC absorption circuits for protecting D15. The 85V voltage output after rectification by D15 is filtered by C17 and voltage-divided by R24, R25, R21, R22, R23, R23* and then superimposed with the voltage of D7 to provide the operating voltage for UE1 BMS. At the same time, it also forms the V1F reference voltage with R17, R18, R16, R15, R14, R13, R13* voltage to constitute the PWM feedback control of the primary side by PC1. C9 and C12 are high-frequency noise elimination capacitors for purifying the V1F reference voltage to prevent clutter interference.

[0006] The foregoing wireless charging overload protection method is characterized in that: the adapter control unit UE1 BMS MCU outputs an adjustment instruction to control the output of the charger to the battery through the BUCK synchronous rectification circuit; the BUCK synchronous buck rectification circuit composed of Q4, L2, Q5, Q6, and Q7 controls the charging current and voltage. R62 1k is the gate drive resistor of Q4, R63 is the gate pull-up resistor, R64 is the gate pull-down resistor, and Q6 is controlled by the gate drive pulse. R61 is the base drive resistor of Q6; R66 1k is the gate drive resistor of Q5, R67 is the gate pull-up resistor, R68 is the gate pull-down resistor, and Q6 is controlled by the gate drive pulse. R65 is the base drive resistor of Q6; D16 is an anti-reverse connection diode to protect the power adapter from being burned out due to the reverse connection of the positive and negative poles of the battery.

[0007] The aforementioned wireless charging over - load protection method is characterized in that: during the over - load protection process of the wireless charger for the battery, when D16 charges the battery, the loop current passes through the 0.1R resistor R61 and the voltage - dividing circuit composed of R28 and R27 and is input to pin 2 of UE1 BMS. After internal operation control, OUT1 and OUT2 PWM outputs control the output of the BUCK circuit. When the output current increases due to some reason, since there is a sampling resistor R61, the voltage across its two ends will also increase, and correspondingly, the voltage of pin 2 of UE1 BMS will also increase. Through internal operation adjustment, the pulse width of OU1 and OUT2 PWM is reduced to reduce the current output. Assume that at this time the load is short - circuited. Due to the short - circuit current, the voltage across R61 will increase rapidly, and this value is much larger than the current increase in normal cases. Reflected to pin 2 of UE1, UE1 will simultaneously send out a shutdown signal. One way is to control the source - side shutdown output of OUT3, and the other way is to control the shutdown of OUT1 and OUT2 PWM outputs. At the same time, the transmitting coil main unit here also detects an abnormal output and closes the output of the transmitting coil resonance frequency.

[0008] The triple protection of the present invention is carried out simultaneously, and the background adapter is informed that there is a short - circuit phenomenon, which needs to be processed, reducing the losses to the device and the charging user during the charging process. Brief Description of the Drawings

[0009] Figure 1 It is the circuit schematic diagram of the present invention. Detailed Embodiments

[0010] The present invention will be further described below in conjunction with the drawings.

[0011] Figure 1It is a preferred embodiment of the present invention, which shows a wireless charging overload protection method, a receiving process, a starting process, a charging voltage control process, an adapter control unit process, and an overload protection process of a battery. It is characterized in that: The L1 resonance inductor receives the energy sent by the transmitting coil. C0 and L1 are in parallel resonance and then form a series resonance with C0* to boost the resonance voltage again. After resonance, it is rectified by a rectifier bridge to convert the high-frequency changing magnetic energy into direct current, and R0 and R0* are used to limit this high voltage. In the circuit, D17 can prevent the high voltage from the back-end switching power supply from returning and surging when it is turned off, so as to avoid generating a higher voltage; D18 provides a voltage and current discharge circuit when the post-stage Q1 switching tube is turned off. The DC voltage output by D17, about 650V - 850V, passes through the FU 3A fuse and the T 5D11 thermistor starting resistor, is divided by two electrolytic capacitors C1 and C2550v120uf in series, and is loaded onto the drain of the Q1 MSFET P-channel regulating tube through the switching transformer T1. The withstand voltage of Q1 is 1200V 3A. Another path is loaded onto the 7th pin of the power switch chip UC3842E through the R3250k starting resistor. The UC3842 internally has an undervoltage lockout circuit, and the opening and closing thresholds are 16V and 10V; R2 is a current sampling resistor. When the output load is too heavy due to some reason, the voltage on R2 increases. This voltage and the voltage dividing circuit composed of R9 and R8 will cause the voltage on the 3rd pin of UC3842 to increase. After being processed by the chip internally, the output PWM becomes narrower, thus reducing the output.

[0012] The foregoing wireless charging overload protection method is characterized in that: when D7 and D15 are forward-conducted during the control process of the charging voltage, a charging voltage output and a voltage for the operation of the backend BMS are established; the DC 24V voltage output by D7 is filtered by the high-frequency filter C01 and the electrolytic capacitor C11 to generate a working voltage; the first path is limited in current by R39 and R40 and applied to the positive electrode of the cooling fan, and the second path is applied to the base of Q3, and its control terminal obtains a conduction voltage, forming a switch connection so that the fan rotates. The third path is applied to the collector of Q2. R31 is an upper bias resistor and the reference output of V2F is 5V working voltage. R32 and R29 are voltage-divided to obtain a 2.5V reference voltage. C04 is a reference voltage noise elimination capacitor; the fourth path is applied to R12, and the voltage division of R12 and R11 is controlled by the reference voltage of V1F. The increase or decrease in voltage caused by the change in the output load is controlled by the feedback of the PC817 optocoupler to adjust the PWM duty cycle output of the primary side so as to achieve the adjustment purpose; RT2 is close to D15. After the temperature control thermistor RT2 is charged, the temperature of RT2 gradually rises with the increase of time. The voltage change caused is output through UE1 BMS OUT3 to control the PC817 to adjust the PWM output of the primary side to offset the influence brought by the temperature change; C18 and R50 are RC absorption circuits for protecting D15. The 85V voltage output after the rectification of D15 is filtered by C17 and voltage-divided by R24, R25, R21, R22, R23, R23* and then superimposed with the voltage of D7 to provide a working voltage for UE1BMS. At the same time, it also forms a V1F reference voltage with R17, R18, R16, R15, R14, R13, R13* voltage to constitute the PWM feedback control of the primary side by PC1. C9 and C12 are high-frequency noise elimination capacitors, which are used to purify the V1F reference voltage to prevent clutter interference.

[0013] The foregoing wireless charging overload protection method is characterized in that: the adapter control unit UE1 BMS MCU outputs an adjustment instruction to control the output of the charger to the battery through the BUCK synchronous rectification circuit; the BUCK synchronous step-down rectification circuit composed of Q4, L2, Q5, Q6, and Q7 controls the charging current and voltage. R62 1k is the gate drive resistor of Q4, R63 is the gate pull-up resistor, R64 is the gate pull-down resistor, and Q6 is the gate drive pulse control. R61 is the base drive resistor of Q6; R66 1k is the gate drive resistor of Q5, R67 is the gate pull-up resistor, R68 is the gate pull-down resistor, and Q6 is the gate drive pulse control. R65 is the base drive resistor of Q6; D16 is an anti-reverse connection diode to protect the power adapter from being burned out due to the reverse connection of the positive and negative electrodes of the battery.

[0014] The foregoing wireless charging overload protection method is characterized in that: during the overload protection process of the wireless charger for the battery, when D16 charges the battery, the loop current is input to pin 2 of UE1 BMS via the R61 0.1R resistor and the voltage dividing circuit composed of R28 and R27, and the internal operation control OUT1 OUT2 PWM outputs to control the output of the BUCK circuit. When the output current increases for some reason, due to the R61 sampling resistor, the voltage across its two ends will also increase, and correspondingly, the voltage of pin 2 of UE1 BMS will also increase. The pulse width of OU1 OUT2 PWM is adjusted downward through internal operation to reduce the current output. Assuming that the load is short-circuited at this time, the voltage across R61 will increase rapidly due to the short-circuit current, and this value is much larger than the normally increased current. Reflected to pin 2 of UE1, UE1 will simultaneously send a shutdown signal, one path to the OUT3 control source to shut down the output, and the other path to control the shutdown of the OUT1 OUT2 PWM output. At the same time, the transmitter coil main unit here also detects an abnormal output and shuts down the transmitter coil resonance frequency output.

[0015] The triple protection of the present invention is carried out simultaneously, and the background adapter is informed that a short-circuit phenomenon has occurred and needs to be processed, effectively reducing the losses to the device and the charging user during the charging process.

Claims

1. Wireless charging overload protection method, comprising: Receiving process, starting process, charging voltage control process, adapter control unit process, battery overloading protection process, characterized in that: The L1 resonant inductor receives the energy sent by the transmitting coil. C0 and L1 are in parallel resonance and then form a series resonance with C0* to boost the resonant voltage again. After resonance, it is rectified by a rectifier bridge to convert the high-frequency changing magnetic energy into direct current, and R0 and R0* are used to limit the high voltage. In the circuit, D17 can prevent the high voltage from the back-end switching power supply from returning and surging when it is turned off, thus generating a higher voltage; D18 provides a voltage and current discharge circuit when the post-stage Q1 switching tube is turned off; The DC voltage of 650V - 850V output by D17 passes through the FU 3A fuse and the T 5D11 thermistor starting resistor, is divided by two electrolytic capacitors C1 and C2550v120uf in series, and is loaded onto the drain of the Q1 MOSFET P-channel regulating tube through the switching transformer T1. The withstand voltage of Q1 is 1200V 3A; Another path is loaded onto the 7th pin of the power switch chip UC3842E through the R3 250k starting resistor. The UC3842 internally has an under-voltage lockout circuit, and the turn-on and turn-off thresholds are 16V and 10V; R2 is a current sampling resistor. When the output load is too heavy due to some reason, the voltage on R2 increases. This voltage and the voltage-dividing circuit composed of R9 and R8 will cause the voltage of the 3rd pin of UC3842 to increase. After internal processing by the chip, the output PWM becomes narrower, thereby reducing the output. During the control process of the charging voltage, when D7 and D15 are forward-conducting, the charging voltage output and the voltage for the operation of the back-end BMS are established; The DC 24V voltage output by D7 passes through C01 high-frequency filtering and C11 electrolytic capacitor filtering to generate the working voltage; The first path is limited by R39 and R40 and added to the positive pole of the cooling fan. The second path is loaded onto the base of Q3, and its control terminal obtains the conduction voltage, forming a switch connection to make the fan run; The third path is loaded onto the collector of Q2. R31 is the upper bias resistor and the V2F reference outputs a 5V working voltage. R32 and R29 are voltage-divided to obtain a 2.5V reference voltage. C04 is the noise elimination capacitor for the reference voltage; The fourth path is loaded onto R12. The voltage division of R12 and R11 is controlled by the reference voltage of V1F. The voltage increase or decrease caused by the change of the output load is fed back through the PC817 optocoupler to control the PWM duty cycle output of the primary side, thereby achieving the adjustment purpose. The adapter control unit UE1BMS MCU outputs an adjustment instruction to control the output of the charge to the battery through the BUCK synchronous rectification circuit.

2. The wireless charging overcurrent protection method according to claim 1, wherein: RT2 is close to D15. After the temperature control thermistor RT2 is charged, its temperature gradually rises with the increase of time. The resulting voltage change is output through UE1 BMS OUT3 to control PC817 to adjust the primary PWM output to offset the influence brought by the temperature change; C18 and R50 are for the RC absorption circuit to protect D15; the 85V voltage output after D15 is rectified is filtered by C17 and divided by R24, R25, R21, R22, R23, R23* and then superimposed with the D7 voltage to provide the working voltage for UE1 BMS. At the same time, it also forms a V1F reference voltage with the voltages of R17, R18, R16, R15, R14, R13, R13* to constitute the PWM feedback control of PC1 to the primary side. C9 and C12 are high-frequency noise suppression capacitors, which are used to purify the V1F reference voltage to prevent clutter interference.

3. The wireless charging overload protection method according to claim 1, wherein: The BUCK synchronous buck rectification circuit composed of Q4, L2, Q5, Q6, and Q7 controls the charging current and voltage. R62 1k is the gate drive resistor of Q4, R63 is the gate pull-up resistor, R64 is the gate pull-down resistor, and Q6 controls the gate drive pulse. R61 is the base drive resistor of Q6; R66 1k is the gate drive resistor of Q5, R67 is the gate pull-up resistor, R68 is the gate pull-down resistor, and Q6 controls the gate drive pulse. R65 is the base drive resistor of Q6; D16 is an anti-reverse connection diode to protect the power adapter from being burned out due to the reverse connection of the battery positive and negative poles.

4. The wireless charging over - load protection method according to claim 1, wherein: In the overcurrent protection process of the wireless charger for the battery, when D16 charges the battery, the loop current is input to pin 2 of UE1 BMS through the R61 0.1R resistor and the voltage division circuit composed of R28 and R27, and the internal operation control OUT1 OUT2 PWM output controls the output of the BUCK circuit. When the output current increases due to some reason, due to the R61 sampling resistor, the voltage across its two ends will also increase, and the voltage of pin 2 of UE1 BMS will also increase accordingly. The internal operation adjusts to reduce the OU1 OUT2 PWM pulse width to reduce the current output. Assuming that the load is short-circuited at this time, the short-circuit current will cause the voltage across R61 to increase rapidly, which is greater than the current increase in normal cases. Reflected to pin 2 of UE1, UE1 will send out a shutdown signal at the same time. One way is to control the source side to shut down the output through OUT3, and the other way is to control the OUT1OUT2 to shut down the PWM output. At the same time, the transmitting coil main unit here also detects an output abnormality and shuts down the transmitting coil resonance frequency output.

Images