Voltage regulation circuits, charging devices and systems suitable for multiple platforms

Abstract

The present application provides a voltage regulation circuit, charging device, and system that are adaptable to multiple platforms. The system comprises a current pulse acquisition unit, a voltage comparison unit, a resistance value adjustment unit, a PFC control unit, a pulse generation unit, a voltage divider unit, and a voltage adjustment unit. The current pulse acquisition unit is connected to the PFC correction circuit and the voltage comparison unit, which is further connected to the resistance value adjustment unit. The resistance value adjustment unit is further connected to the PFC control unit via the voltage divider unit. The pulse generation unit is connected to the resistance value adjustment unit, and the PFC control unit is connected to the voltage adjustment unit. The system collects the output current pulse width of the DC-DC charging circuit and adjusts the output voltage of the PFC correction circuit based on the duty cycle reflected by the output current pulse width. This achieves the purpose of adjusting the duty cycle and improving charging efficiency and safety.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicle charging, and in particular to a voltage regulation circuit, charging equipment, and system that are adaptable to multiple platforms. Background Art

[0002] Electric vehicles are clean, efficient, and sustainable vehicles powered by an onboard electrical system, with motors driving the wheels. Because they are powered by electricity, they can achieve zero or very low emissions and have minimal impact on the environment. Consequently, electric vehicles have experienced rapid growth in recent years.

[0003] Among them, when charging electric vehicles, a DC-DC charging device is required. In the DC-DC charging device, a high-efficiency phase-shift resonant full-bridge width modulation control circuit is connected to a power factor correction (PFC), that is, a PFC correction circuit. When the switching pulse duty cycle of the circuit is large, the transformer recovery time is insufficient, resulting in hysteresis heating, reducing conversion efficiency and reliability; when the switching pulse duty cycle is small, the peak current of the power tube is large, causing the power tube to heat up, reducing conversion efficiency and reliability.

[0004] Currently, electric vehicle charging platforms include two voltage levels: 400V and 800V. When using DC-DC charging equipment to switch between the two voltage levels, the charging voltages of electric vehicles are different, but the output voltage of the PFC correction circuit is fixed. Therefore, the switching pulse duty cycle will change, thereby reducing charging efficiency and charging reliability.

[0005] Therefore, it is necessary to adjust the switching pulse duty cycle in the DC-DC charging equipment to improve the charging efficiency and safety factor. Summary of the Invention

[0006] The present application provides a voltage adjustment circuit, charging device and system that are adaptable to multiple platforms to solve the technical problems mentioned in the background technology.

[0007] In a first aspect, the present application provides a voltage regulation circuit adapted for multiple platforms, which is applied to a PFC correction circuit. The PFC correction circuit is connected to a DC-DC charging circuit. The PFC correction circuit is configured to output DC power of a first voltage value to the DC-DC charging circuit. The voltage regulation circuit adapted for multiple platforms includes:

[0008] Current pulse acquisition unit, voltage comparison unit, resistance value adjustment unit, PFC control unit, pulse generation unit, voltage division unit and voltage adjustment unit;

[0009] The current pulse acquisition unit is connected to the PFC correction circuit and the voltage comparison unit, the voltage comparison unit is further connected to the resistance value adjustment unit, the resistance value adjustment unit is further connected to the PFC control unit via the voltage divider unit, the pulse generation unit is connected to the resistance value adjustment unit, and the PFC control unit is connected to the voltage adjustment unit;

[0010] The current pulse acquisition unit is used to acquire the output current pulse width of the DC-DC charging circuit and send the output current pulse width to the voltage comparison unit;

[0011] the voltage comparison unit is configured to obtain a first output voltage of the corresponding DC-DC charging circuit based on the output current pulse width, and output a control signal to the resistance adjustment unit based on the first output voltage and a first threshold voltage, where the first threshold voltage is determined based on a target duty cycle corresponding to the DC-DC charging circuit;

[0012] The pulse generating unit is configured to output a pulse signal to the resistance adjusting unit, wherein the pulse signal is configured to drive the resistance adjusting unit to adjust the output resistance;

[0013] The resistance value adjustment unit is configured to adjust and output the output resistance according to the control signal and under the drive of the pulse signal;

[0014] The voltage dividing unit is configured to output a divided voltage to the PFC control unit according to the output resistance value;

[0015] The PFC control unit is configured to send a width modulation signal to the voltage adjustment unit according to the divided voltage and the second threshold voltage;

[0016] The voltage adjustment unit is configured to control and adjust the voltage of the output DC power of the PFC correction circuit according to the width modulation signal so that the duty cycle of the DC-DC charging circuit is the target duty cycle.

[0017] Optionally, the voltage comparison unit includes: a first comparator, wherein the first input terminal, the second input terminal, and the first output terminal inside the first comparator constitute a first buffer comparator, and the third input terminal, the fourth input terminal, and the second output terminal inside the first comparator constitute a second buffer comparator;

[0018] The first input terminal is connected to the current pulse acquisition unit, and is used to input the first output voltage to the first comparator through the first input terminal;

[0019] The second input terminal, the first output terminal, and the fourth input terminal share a common ground, so that the fourth input terminal receives the first output voltage;

[0020] The third input terminal is connected to the first threshold voltage, and the second output terminal is connected to the resistance value adjustment unit, and is used to compare the first output voltage with the first threshold voltage and output the control signal according to the comparison result.

[0021] Optionally, the resistance value adjustment unit includes: a digital potentiometer;

[0022] The first end of the digital potentiometer is connected to the voltage comparison unit, the second end of the digital potentiometer is connected to the pulse generation unit, and the resistance output end of the digital potentiometer is connected to the voltage dividing unit;

[0023] The first end of the digital potentiometer is used to receive the control signal;

[0024] The second end of the digital potentiometer is used to receive the pulse signal;

[0025] The resistance output end is used to adjust and output the output resistance according to the control signal under the drive of the pulse signal.

[0026] Optionally, the voltage divider unit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor, wherein the first resistor is connected in parallel with the output resistor and then in series with the second resistor to form a first branch, the third resistor, the fourth resistor, and the fifth resistor are connected in series at the output end of the PFC correction circuit, and the first branch is connected in parallel with the fifth resistor and then connected to the PFC control unit;

[0027] The first resistor, the second resistor, the third resistor, the fourth resistor and the fifth resistor are used to adjust the magnitude of the divided voltage according to the magnitude of the output resistor, and transmit the divided voltage to the PFC control unit.

[0028] Optionally, the PFC control unit includes: a second comparator, a first end of the second comparator is connected to the voltage dividing unit, and a second end of the second comparator is connected to the voltage adjusting unit;

[0029] The first terminal of the second comparator is used to receive the divided voltage;

[0030] The second terminal of the second comparator is used to output the width modulation signal according to the divided voltage and the second threshold voltage.

[0031] Optionally, the voltage adjustment unit includes: a sixth resistor, an eighth resistor, and an insulated gate field effect transistor, the eighth resistor being connected between the sixth resistor, the first end of the insulated gate field effect transistor, and the PFC control unit, and the second end of the insulated gate field effect transistor and the third end of the insulated gate field effect transistor being connected to the PFC correction circuit;

[0032] The eighth resistor is used to transmit the width modulation signal to the first end of the insulated gate field effect transistor;

[0033] The insulated gate field effect transistor is used to be turned on according to the width modulation signal and determine the conduction time, and adjust the output voltage of the PFC correction circuit according to the conduction time.

[0034] Optionally, the current pulse acquisition unit includes: a first diode, a second diode, a third diode, a seventh resistor, and a transformer, one side winding of the transformer is connected to the output end of the PFC correction circuit, one end of the other side winding of the transformer is connected to the seventh resistor and then grounded, the other end of the other side winding of the transformer is grounded, the first diode, the second diode, and the seventh resistor are connected in parallel, the cathode of the first diode and the anode of the second diode are connected to the anode of the third diode, and the cathode of the third diode is connected to the voltage comparison unit;

[0035] The transformer is configured to obtain the output current of the DC-DC charging circuit through one winding of the transformer and transmit the output current of the DC-DC charging circuit to the other winding of the transformer;

[0036] The first diode and the second diode are used to absorb the high voltage and high output current generated when the DC-DC charging circuit has an output short circuit or overcurrent;

[0037] The third diode is used to detect the output current of the DC-DC charging circuit and output the output current pulse width.

[0038] Optionally, the pulse generating unit includes: a low-frequency oscillator, wherein a pulse output terminal of the low-frequency oscillator is connected to the resistance value adjusting unit;

[0039] The low-frequency oscillator is used to output the pulse signal to the resistance value adjustment unit.

[0040] In a second aspect, the present application provides a universal multi-input universal AC-DC charging device, comprising: at least one AC-DC input circuit, the PFC correction circuit, and the multi-platform adaptable voltage adjustment circuit as described in any one of the first aspects;

[0041] The at least one AC-DC input circuit is connected to the PFC correction circuit, and the multi-platform adaptable voltage adjustment circuit is connected to the PFC correction circuit;

[0042] The AC-DC input circuit is used to connect to the mains, convert AC-DC power after obtaining AC power to obtain pulsed DC power, and send the pulsed DC power to the PFC correction circuit;

[0043] The PFC correction circuit is configured to output DC power to the DC-DC charging circuit by adjusting the power factor of the pulsed DC power;

[0044] The multi-platform adaptable voltage adjustment circuit is used to adjust the voltage of the output DC power of the PFC correction circuit according to the output current of the DC-DC charging circuit.

[0045] In a third aspect, the present application provides an electric vehicle charging system, characterized by comprising: the universal multi-input universal AC-DC charging device and the DC-DC charging device described in the second aspect, the DC-DC charging device including the DC-DC charging circuit, the universal multi-input universal AC-DC charging device being connected to the DC-DC charging device;

[0046] The universal multi-input universal AC-DC charging device is used to connect to the mains, obtain AC power, perform AC-DC conversion and power factor correction on the AC power, and then obtain the output DC power, and send the output DC power to the DC-DC charging device;

[0047] The DC-DC charging device is used to charge the electric vehicle according to the output DC power.

[0048] The multi-platform voltage adjustment circuit, charging device, and system provided in the present application are configured with a current pulse acquisition unit, a voltage comparison unit, a resistance adjustment unit, a PFC control unit, a pulse generation unit, a voltage divider unit, and a voltage adjustment unit. The current pulse acquisition unit is connected to the PFC correction circuit and the voltage comparison unit, which is further connected to the resistance adjustment unit. The resistance adjustment unit is further connected to the PFC control unit via the voltage divider unit. The pulse generation unit is connected to the resistance adjustment unit, and the PFC control unit is connected to the voltage adjustment unit. This enables acquisition of the output current pulse width of the DC-DC charging circuit, and adjusts the output voltage of the PFC correction circuit based on the duty cycle reflected by the output current pulse width. This achieves the purpose of adjusting the duty cycle and improving charging efficiency and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0050] Figure 1 A structural diagram of a voltage regulation circuit adapted to multiple platforms provided in one embodiment of the present application;

[0051] Figure 2 A partial circuit diagram of a voltage regulation circuit adapted to multiple platforms provided in one embodiment of the present application;

[0052] Figure 3 A partial circuit diagram of a voltage regulation circuit adapted to multiple platforms provided by another embodiment of the present application;

[0053] Figure 4 A schematic diagram of the structure of a universal multi-input universal AC-DC charging device provided in one embodiment of the present application;

[0054] Figure 5 A schematic diagram of the structure of an electric vehicle charging system provided in one embodiment of the present application. DETAILED DESCRIPTION

[0055] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application are clearly and completely described below. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts also fall within the scope of protection of this application.

[0056] When charging electric vehicles, a DC-DC charging device is required. A high-efficiency phase-shift resonant full-bridge width modulation control circuit is used in the DC-DC charging device. When the switching pulse duty cycle of the circuit is relatively large, the transformer recovery time is insufficient, resulting in hysteresis heating, reducing conversion efficiency and reliability. When the switching pulse duty cycle is relatively small, the peak current of the power tube is very large, causing the power tube to heat up, reducing conversion efficiency and reliability.

[0057] In addition, the electric vehicle charging platform includes two voltage levels: 400V and 800V. When using DC-DC charging equipment to switch between the two voltage levels, the charging voltage of the electric vehicle is different, but the output voltage of the PFC correction circuit is fixed. Therefore, the switching pulse duty cycle will change, thereby reducing charging efficiency and charging reliability.

[0058] Therefore, it is necessary to adjust the switching pulse duty cycle in the DC-DC charging equipment to improve the charging efficiency and safety factor.

[0059] Therefore, the present application proposes a voltage adjustment circuit, charging device and system that are adaptable to multiple platforms. The output current pulse width of the DC-DC charging circuit is collected, and then the output current pulse width is compared with the threshold voltage set according to the target duty cycle. The duty cycle corresponding to the output current pulse width is determined based on the comparison result. When the duty cycle is small, it indicates that the voltage value of the output voltage of the PFC correction circuit is large. At this time, the voltage value of the output voltage of the PFC correction circuit is adjusted down; when the duty cycle is large, it indicates that the voltage value of the output voltage of the PFC correction circuit is small. At this time, the voltage value of the output voltage of the PFC correction circuit is adjusted up, thereby adjusting the voltage value of the output voltage of the PFC correction circuit, thereby adjusting the duty cycle and improving the charging efficiency and safety factor.

[0060] Figure 1 This is a structural diagram of a multi-platform voltage regulation circuit according to an embodiment of the present application. The multi-platform voltage regulation circuit 100 is applied to a PFC correction circuit 200, which is connected to a DC-DC charging circuit 300. The PFC correction circuit 200 is configured to output DC power of a first voltage value to the DC-DC charging circuit 300.

[0061] like Figure 1 As shown, the voltage adjustment circuit 100 adapted to multiple platforms includes: a current pulse acquisition unit 110, a voltage comparison unit 120, a resistance value adjustment unit 130, a PFC control unit 140, a pulse generation unit 150, a voltage dividing unit 160 and a voltage adjustment unit 170;

[0062] The current pulse acquisition unit 110 is connected to the PFC correction circuit and the voltage comparison unit 120. The voltage comparison unit 120 is further connected to the resistance value adjustment unit 130. The resistance value adjustment unit 130 is further connected to the PFC control unit 140 via the voltage divider unit 160. The pulse generation unit 150 is connected to the resistance value adjustment unit 130. The PFC control unit 140 is connected to the voltage adjustment unit 170.

[0063] The current pulse acquisition unit 110 is used to acquire the output current pulse width of the DC-DC charging circuit and send the output current pulse width to the voltage comparison unit 120;

[0064] a voltage comparison unit 120 for obtaining a first output voltage of the DC-DC charging circuit according to the output current pulse width, and outputting a control signal to the resistance adjustment unit 130 according to the first output voltage and a first threshold voltage, where the first threshold voltage is determined according to a target duty cycle corresponding to the DC-DC charging circuit;

[0065] The pulse generating unit 150 is configured to output a pulse signal to the resistance adjusting unit 130 , wherein the pulse signal is configured to drive the resistance adjusting unit 130 to adjust the output resistance.

[0066] The resistance value adjustment unit 130 is used to adjust and output the resistance according to the control signal under the drive of the pulse signal;

[0067] The voltage dividing unit 160 is configured to output a divided voltage to the PFC control unit 140 according to the output resistance value;

[0068] The PFC control unit 140 is configured to send a width modulation signal to the voltage adjustment unit 170 according to the divided voltage and the second threshold voltage;

[0069] The voltage adjustment unit 170 is configured to control and adjust the voltage of the DC output of the PFC correction circuit according to the width modulation signal so that the duty cycle of the DC-DC charging circuit is the target duty cycle.

[0070] In this embodiment, when charging an electric vehicle, the DC-DC charging circuit uses a high-efficiency phase-shift resonant full-bridge width modulation control circuit to adjust the voltage and current. In addition, since the PFC correction circuit is connected to the DC-DC charging circuit and the charging circuit forms a single loop, the output current pulse width of the DC-DC charging circuit can be collected by the current pulse collection unit 110 based on the PFC correction circuit.

[0071] The voltage adjustment unit 170 is connected to the output terminal of the PFC correction circuit, and adjusts the voltage of the DC power output by the PFC correction circuit by controlling the on-time of the PFC correction circuit.

[0072] The circuit's operating principle is as follows: When the DC-DC charging circuit charges an electric vehicle, the output voltage of the DC-DC charging circuit also adjusts as the DC power required for charging the electric vehicle adjusts. For example, when the output voltage of the DC-DC charging circuit is adjusted from a high voltage to a low voltage, the output voltage of the PFC correction circuit remains unchanged, causing the duty cycle of the high-efficiency phase-shift resonant full-bridge width modulation control circuit to decrease. This allows the output voltage of the DC-DC charging circuit to be adjusted from a high voltage to a low voltage while the output voltage of the PFC correction circuit remains unchanged. However, the reduced duty cycle will result in a large peak current in the power tube, causing the power tube to heat up and reducing charging efficiency and safety.

[0073] In this embodiment, the output current pulse width of the DC-DC charging circuit is collected in real time by the current pulse collection unit 110. The output current pulse width can reflect the size of the duty cycle. Therefore, when the duty cycle changes, the output current pulse width also changes accordingly, so that changes in the duty cycle can be detected in real time and in a timely manner.

[0074] When the current pulse acquisition unit 110 acquires the output current pulse width, it sends the output current pulse width to the voltage comparison unit 120. Based on the output current pulse width, the voltage comparison unit 120 obtains the corresponding first output voltage of the DC-DC charging circuit, denoted as the PS voltage. The PS voltage is compared with a first threshold voltage, denoted as the VR1 voltage. The VR voltage is the voltage corresponding to the target duty cycle of the high-efficiency phase-shifted resonant full-bridge width modulation control circuit. The target duty cycle is the duty cycle corresponding to when the high-efficiency phase-shifted resonant full-bridge width modulation control circuit operates efficiently and has excellent charging efficiency. Therefore, by comparing the PS voltage with the VR voltage, it is possible to determine whether the acquired duty cycle of the high-efficiency phase-shifted resonant full-bridge width modulation control circuit is the target duty cycle, thereby adjusting the duty cycle if it is not the target duty cycle.

[0075] Since the output voltage of the DC-DC charging circuit is adjusted from a high voltage to a low voltage, the duty cycle is reduced. Therefore, the comparison result of the voltage comparison unit 120 is that the PS voltage is greater than the VR voltage. At this time, the control signal output to the resistance value adjustment unit 130 is a high potential.

[0076] After receiving the high potential, the resistance value adjusting unit 130 increases the resistance Rw stepwise each time it receives the pulse signal transmitted by the pulse generating unit 150 , thereby increasing the resistance value of the resistance Rw.

[0077] The increase in the resistance of resistor Rw increases the divided voltage output by voltage divider unit 160, which is recorded as VS. Since voltage divider unit 160 is connected to PFC control unit 140, PFC control unit 140 receives the change in VS voltage and compares it with a second threshold voltage, which is half the first threshold voltage and is recorded as VR2. At this point, VS voltage should be less than VR2 voltage. Therefore, the pulse width of the pulse width modulation signal sent by PFC control unit 140 to voltage adjustment unit 170 is narrow.

[0078] The pulse width of the width modulation signal is used to control the on-time of the PFC correction circuit. The longer the on-time, the greater the output voltage. Therefore, when the width modulation signal is a narrow pulse width modulation signal, the on-time of the PFC correction circuit is shorter, so the output DC voltage is reduced, thereby increasing the duty cycle of the high-efficiency phase-shift resonant full-bridge width modulation control circuit.

[0079] When the output voltage of the DC-DC charging circuit is adjusted from a low voltage to a high voltage, its working principle can be referred to above and will not be repeated here.

[0080] This embodiment includes a current pulse acquisition unit 110, a voltage comparison unit 120, a resistance adjustment unit 130, a PFC control unit 140, a pulse generation unit 150, a voltage divider unit 160, and a voltage adjustment unit 170. The current pulse acquisition unit 110 is connected to the PFC correction circuit and the voltage comparison unit 120, which is further connected to the resistance adjustment unit 130. The resistance adjustment unit 130 is further connected to the PFC control unit 140 via the voltage divider unit 160. The pulse generation unit 150 is connected to the resistance adjustment unit 130, and the PFC control unit 140 is connected to the voltage adjustment unit 170. This allows for acquisition of the output current pulse width of the DC-DC charging circuit, and adjusts the output voltage of the PFC correction circuit based on the duty cycle reflected by the output current pulse width. This adjusts the duty cycle, thereby improving charging efficiency and safety.

[0081] Optionally, based on the above embodiment, Figure 2 As shown, the voltage comparison unit 120 includes: a first comparator U1, a first input terminal A+, a second input terminal A- and a first output terminal Ao inside the first comparator U1 constitute a first buffer comparator, and a third input terminal B+, a fourth input terminal B- and a second output terminal Bo inside the first comparator U1 constitute a second buffer comparator;

[0082] The first input terminal A+ is connected to the current pulse acquisition unit 110 and is used to input the first output voltage to the first comparator U1 through the first input terminal A+;

[0083] The second input terminal A−, the first output terminal Ao, and the fourth input terminal are grounded, so that the fourth input terminal receives the first output voltage;

[0084] The third input terminal B+ is connected to the first threshold voltage, and the second output terminal Bo is connected to the resistance value adjustment unit 130 for comparing the first output voltage with the first threshold voltage and outputting a control signal according to the comparison result.

[0085] In this embodiment, the first comparator U1 can be, for example, a high-speed buffer comparator. The internal input terminal A+, input terminal A- and output terminal Ao of the high-speed buffer comparator constitute a first buffer comparator, and the input terminal B+, input terminal B- and output terminal Bo constitute a second buffer comparator.

[0086] Input terminal A+ is used to receive the output current pulse width to obtain the PS voltage, while input terminal B+ is used to receive the VR1 voltage. Connecting input terminal A- to output terminal Ao reduces output signal fluctuations and noise, improving the stability and accuracy of the first buffer comparator. Input terminal B- is also connected to input terminal A- and output terminal Ao, effectively receiving the PS voltage.

[0087] The second buffer comparator compares the PS voltage and the VR1 voltage, and determines whether the output control signal is a high potential or a low potential based on the comparison result. When the PS voltage is greater than the VR1 voltage, the control signal is a high potential; when the PS voltage is less than the VR1 voltage, the control signal is a low potential.

[0088] In this embodiment, a high-speed buffer comparator is used, and the first buffer comparator and the second buffer comparator in the high-speed buffer comparator are utilized to compare the PS voltage and the VR1 voltage, thereby ensuring the accuracy of the comparison result.

[0089] Optionally, based on the above embodiment, Figure 2 As shown, the resistance value adjustment unit 130 includes: a digital potentiometer U2;

[0090] A first end of the digital potentiometer U2 is connected to the voltage comparison unit 120 , a second end of the digital potentiometer U2 is connected to the pulse generation unit 150 , and a resistance output end of the digital potentiometer U2 is connected to the voltage divider unit 160 ;

[0091] A first terminal of the digital potentiometer U2 is used to receive a control signal;

[0092] The second end of the digital potentiometer U2 is used to receive the pulse signal;

[0093] The resistance output terminal is used to adjust and output resistance according to the control signal under the drive of the pulse signal.

[0094] In this embodiment, the pulse generation unit 150 is configured to output a pulsed square wave, for example, a 10 Hz square wave. The digital potentiometer U2 is configured to output an adjustable output resistor Rw. When the digital potentiometer U2 receives a control signal, it adjusts the resistance of the output resistor Rw each time it receives a 10 Hz square wave. Specifically, when the control signal is high, the output resistor Rw increases in steps, and when the control signal is low, the output resistor Rw decreases in steps, thereby adjusting the resistance.

[0095] Optionally, based on the above embodiment, Figure 2As shown, the voltage divider unit 160 includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, and a fifth resistor R5. The first resistor R1 is connected in parallel with the output resistor and then in series with the second resistor R2 to form a first branch. The third resistor R3, the fourth resistor R4, and the fifth resistor R5 are connected in series at the output end of the PFC correction circuit. The first branch is connected in parallel with the fifth resistor R5 and is connected to the PFC control unit 140.

[0096] The first resistor R1 , the second resistor R2 , the third resistor R3 , the fourth resistor R4 and the fifth resistor R5 are used to adjust the divided voltage according to the output resistance and transmit the divided voltage to the PFC control unit 140 .

[0097] In this embodiment, in terms of circuit structure, the output resistor Rw is connected in parallel with the first resistor R1, and then in series with the second resistor R2. The third resistor R3, the fourth resistor R4, and the fifth resistor R5 are connected in series and then in parallel with the PFC correction circuit. The branch formed by the output resistor Rw, the first resistor R1, and the second resistor R2 is connected in parallel with the fifth resistor R5, and the connection point is connected to the PFC control unit 140.

[0098] The voltage divider unit 160 operates as follows: when the resistance of the output resistor Rw increases, the resistance of the output resistor Rw connected in parallel with the first resistor R1 decreases, thereby reducing the resistance of the branch formed by the output resistor Rw, the first resistor R1, and the second resistor R2. This in turn increases the resistance of the branch formed by the output resistor Rw, the first resistor R1, the second resistor R2, and the fifth resistor R5 connected in parallel. This increases the VS voltage at the connection point of the branch formed by the output resistor Rw, the first resistor R1, the second resistor R2, and the fifth resistor R5 connected in parallel. Consequently, the VS voltage input to the PFC control unit 140 increases.

[0099] When the resistance of the output resistor Rw decreases, the working process is similar to the above and will not be described again here.

[0100] In this embodiment, the output resistor Rw is connected in parallel with the first resistor R1 in the voltage dividing unit 160 , thereby achieving the purpose of adjusting the VS voltage according to the resistance value of the output resistor Rw.

[0101] Optionally, based on the above embodiment, Figure 2 As shown, the PFC control unit 140 includes: a second comparator U3, a first end of the second comparator U3 is connected to the voltage dividing unit 160, and a second end of the second comparator U3 is connected to the voltage adjusting unit 170;

[0102] A first terminal of the second comparator U3 is used to receive the divided voltage;

[0103] The second terminal of the second comparator U3 is used to output a width modulation signal according to the divided voltage and the second threshold voltage.

[0104] In this embodiment, the second comparator U3 may be a device having comparator functionality, wherein the second comparator U3 has a built-in second threshold voltage, namely, VR2. After receiving the VS voltage, the second comparator U3 compares the VS voltage with the VR2 voltage. When the VS voltage is greater than VR2, the second comparator U3 sends a wide pulse width modulated signal to the voltage adjustment unit 170; when the VS voltage is less than VR2, the second comparator U3 sends a narrow pulse width modulated signal to the voltage adjustment unit 170.

[0105] In this embodiment, a second comparator U3 is provided to compare the VS voltage with the VR2 voltage, and a pulse width modulation signal of a corresponding pulse width is output according to the comparison result, thereby controlling the conduction time of the PFC correction circuit.

[0106] Optionally, based on the above embodiment, Figure 2 As shown, the voltage adjustment unit 170 includes: a sixth resistor R6, an eighth resistor R8, and an insulated gate field effect transistor, the eighth resistor R8 is connected between the sixth resistor R6, the first end of the insulated gate field effect transistor, and the PFC control unit 140, and the second end of the insulated gate field effect transistor and the third end of the insulated gate field effect transistor are connected to the PFC correction circuit;

[0107] The eighth resistor R8 is used to transmit the width modulation signal to the first end of the insulated gate field effect transistor.

[0108] The insulated gate field effect transistor is used to conduct according to the width modulation signal and determine the conduction time, and adjust the output voltage of the PFC correction circuit according to the conduction time.

[0109] In this embodiment, the insulated gate field effect transistor may be, for example, an insulation-enhanced N-MOS transistor M, wherein a gate of the N-MOS transistor M is connected to the PFC control unit 140 and grounded via a sixth resistor R6, and a drain and a source of the N-MOS transistor M are connected to the PFC control unit 140.

[0110] When the PFC control unit 140 outputs a width modulation signal, the width modulation signal is transmitted to the gate of the N-MOS transistor M via the eighth resistor R8. After the gate of the N-MOS transistor M receives the width modulation signal, the N-MOS transistor M is turned on. The on-time of the N-MOS transistor M is controlled by the pulse width of the width modulation signal. When the N-MOS transistor M is on, the inductor L1 absorbs energy. When the N-MOS transistor M is off, the inductor L1 outputs energy, i.e., an output voltage. The more energy the inductor L1 absorbs, the higher the output voltage. Therefore, the longer the on-time of the N-MOS transistor M, the higher the output voltage. Therefore, by adjusting the on-time of the N-MOS transistor M, the output voltage of the PFC correction circuit is adjusted.

[0111] Optionally, based on the above embodiment, Figure 3 As shown, the current pulse acquisition unit 110 includes: a first diode D1, a second diode D2, a third diode D3, a seventh resistor R7, and a transformer CS1. One winding of the transformer CS1 is connected to the output end of the PFC correction circuit, one end of the other winding of the transformer CS1 is connected to the seventh resistor R7 and then grounded, and the other end of the other winding of the transformer CS1 is grounded. The first diode D1, the second diode D2, and the seventh resistor R7 are connected in parallel. The cathode of the first diode D1 and the anode of the second diode D2 are connected to the anode of the third diode D3. The cathode of the third diode D3 is connected to the voltage comparison unit 120 (not shown in the figure).

[0112] Transformer CS1, used to obtain the output current of the DC-DC charging circuit through one winding of transformer CS1, and transmit the output current of the DC-DC charging circuit to the other winding of transformer CS1;

[0113] The first diode D1 and the second diode D2 are used to absorb the high voltage and high output current generated when the DC-DC charging circuit has an output short circuit or overcurrent;

[0114] The third diode D3 is used to detect the output current of the DC-DC charging circuit and output the current pulse width.

[0115] In this embodiment, since other circuits are connected between the current pulse acquisition unit 110 and other units in an actual circuit, for ease of description, Figure 3 The current pulse acquisition unit 110 is shown in FIG.

[0116] The DC-DC charging circuit is connected between output terminals A and B of the PFC correction circuit. One winding of transformer CS1 forms a loop from output terminal A to output terminal B of the PFC correction circuit. Therefore, the output current pulse width can be sampled through this winding and then transmitted to the third diode D3 through the other winding of transformer CS1.

[0117] Among them, the seventh resistor R7 is used to prevent the two ends of the other side winding of the transformer CS1 from being short-circuited. The first diode D1 and the second diode D2 use high-conduction voltage drop diodes and are connected in anti-parallel. They can absorb the high voltage and large output current generated when the DC-DC charging circuit has an output short circuit or overcurrent. The third diode D3 uses a low-conduction voltage drop diode to output current pulse width.

[0118] In this embodiment, the current pulse acquisition unit 110, which is composed of the first diode D1, the second diode D2, the third diode D3, the seventh resistor R7, and the transformer CS1, not only isolates the current pulse acquisition unit 110 from the DC-DC charging circuit through the transformer CS1, but also acquires the output current pulse width, thereby adaptively adjusting the output voltage of the PFC correction circuit according to changes in the output voltage of the DC-DC charging circuit.

[0119] Optionally, based on the above embodiment, Figure 2 As shown, the pulse generating unit 150 includes: a low frequency oscillator U4, a pulse output end of the low frequency oscillator U4 is connected to the resistance value adjusting unit 130;

[0120] The low-frequency oscillator U4 is configured to output a pulse signal to the resistance adjustment unit 130 .

[0121] In this embodiment, the low frequency oscillator U4 is used to output a 10 Hz pulse signal to the resistance adjustment unit 130 , so that the resistance adjustment unit 130 performs stepwise adjustment on the resistance of the output resistor Rw when enabled by the 10 Hz pulse signal.

[0122] It should be noted that Figure 2 and Figure 3 Other components are also shown, among which those marked as R only represent resistors and are not used to represent resistance values, those marked as C only represent capacitors and are not used to represent resistance and capacitance, and those marked as L only represent inductors and are not used to represent inductive reactance. Moreover, these components do not involve the technical solutions of the present application and are therefore not described in detail. For details, please refer to the prior art.

[0123] Figure 4 This is a schematic diagram of the structure of a universal multi-input universal AC-DC charging device provided in one embodiment of the present application. Figure 4 As shown, the universal multi-input universal AC-DC charging device 1000 includes: at least one AC-DC input circuit 400, a PFC correction circuit 200 and the multi-platform adaptable voltage adjustment circuit 100 shown in any of the above embodiments;

[0124] At least one AC-DC input circuit 400 is connected to the PFC correction circuit 200, and the multi-platform voltage adjustment circuit 100 is connected to the PFC correction circuit 200;

[0125] The AC-DC input circuit 400 is used to connect to the mains, convert AC power into DC power after receiving it, and send the DC power to the PFC correction circuit 200;

[0126] a PFC correction circuit 200 for outputting DC power to the DC-DC charging circuit by adjusting the power factor of the pulsed DC power;

[0127] The voltage adjustment circuit 100 adapted to multiple platforms is used to adjust the voltage of the DC output of the PFC correction circuit 200 according to the output current of the DC-DC charging circuit.

[0128] In this embodiment, the universal multi-input universal AC-DC charging device can simultaneously access AC power provided by multiple mains through at least one AC-DC input circuit 400, and isolate and rectify the AC power to obtain pulsed DC power, which is then transmitted to the PFC correction circuit 200.

[0129] The PFC correction circuit 200 performs power factor adjustment on the pulsed DC power. The voltage of the output DC power is controlled by the multi-platform voltage adjustment circuit 100, allowing the voltage of the DC power output by the PFC correction circuit 200 to be adjusted according to the charging voltage of the electric vehicle. The process of adjusting the voltage of the DC power output by the multi-platform voltage adjustment circuit 100 is similar to the above-described embodiment and will not be further described here.

[0130] In this embodiment, a universal multi-input universal AC-DC charging device includes at least one AC-DC input circuit 400, a PFC correction circuit 200, and the multi-platform adaptable voltage adjustment circuit 100 shown in any of the above embodiments. This allows the voltage of the DC power output by the PFC correction circuit 200 to be adjusted according to the charging voltage of the electric vehicle, thereby achieving high charging efficiency when charging the electric vehicle.

[0131] Figure 5 This is a schematic diagram of the structure of an electric vehicle charging system provided in one embodiment of the present application. Figure 5 As shown, the electric vehicle charging system includes: the universal multi-input universal AC-DC charging device 1000 and the DC-DC charging device 2000 shown in the above embodiment, the DC-DC charging device 2000 includes a DC-DC charging circuit 300, and the universal multi-input universal AC-DC charging device 1000 is connected to the DC-DC charging device 2000;

[0132] Universal multi-input universal AC-DC charging device 1000, used to connect to the mains, obtain AC power, perform AC-DC conversion and power factor correction, obtain output DC power, and send the output DC power to DC-DC charging device 2000;

[0133] The DC-DC charging device 2000 is used to charge an electric vehicle based on the output DC power.

[0134] In this embodiment, the universal multi-input universal AC-DC charging device 1000 is connected to the mains, converts the AC power of the mains into output DC power, and then transmits the output DC power to the DC-DC charging device 2000.

[0135] The DC-DC charging device 2000 includes a DC-DC charging circuit 300, which outputs DC power and transmits it to the DC-DC charging circuit 300. The DC-DC charging circuit 300 performs rectification, filtering, and other processing on the output DC power to obtain DC power with a charging voltage suitable for electric vehicles, and directly charges the electric vehicles.

[0136] Furthermore, since the universal multi-input universal AC-DC charging device 1000 can adjust the voltage of the DC power output by the universal multi-input universal AC-DC charging device 1000 according to the voltage of the DC-DC charging circuit 300 charging the electric vehicle, the electric vehicle charging system can adaptively adjust the voltage of the DC power output by the universal multi-input universal AC-DC charging device 1000 according to the charging voltage of the electric vehicle when charging the electric vehicle, thereby maintaining a high charging efficiency for the charging battery.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A voltage regulation circuit adapted to multiple platforms, characterized in that: Applied to a PFC correction circuit, the PFC correction circuit is connected to a DC-DC charging circuit, the PFC correction circuit is used to output DC power of a first voltage value to the DC-DC charging circuit, and the voltage adjustment circuit adapted to multiple platforms includes: Current pulse acquisition unit, voltage comparison unit, resistance value adjustment unit, PFC control unit, pulse generation unit, voltage division unit and voltage adjustment unit; The current pulse acquisition unit is connected to the PFC correction circuit and the voltage comparison unit, the voltage comparison unit is further connected to the resistance value adjustment unit, the resistance value adjustment unit is further connected to the PFC control unit via the voltage divider unit, the pulse generation unit is connected to the resistance value adjustment unit, and the PFC control unit is connected to the voltage adjustment unit; The current pulse acquisition unit is used to acquire the output current pulse width of the DC-DC charging circuit and send the output current pulse width to the voltage comparison unit; the voltage comparison unit is configured to obtain a first output voltage of the corresponding DC-DC charging circuit based on the output current pulse width, and output a control signal to the resistance adjustment unit based on the first output voltage and a first threshold voltage, where the first threshold voltage is determined based on a target duty cycle corresponding to the DC-DC charging circuit; The pulse generating unit is configured to output a pulse signal to the resistance adjusting unit, wherein the pulse signal is configured to drive the resistance adjusting unit to adjust the output resistance; The resistance value adjustment unit is configured to adjust and output the output resistance according to the control signal and under the drive of the pulse signal; The voltage dividing unit is configured to output a divided voltage to the PFC control unit according to the output resistance value; The PFC control unit is configured to send a width modulation signal to the voltage adjustment unit according to the divided voltage and the second threshold voltage; The voltage adjustment unit is configured to control and adjust the voltage of the output DC power of the PFC correction circuit according to the width modulation signal so that the duty cycle of the DC-DC charging circuit is the target duty cycle.

2. The multi-platform voltage regulation circuit according to claim 1, wherein: The voltage comparison unit includes: a first comparator, wherein the first input terminal, the second input terminal and the first output terminal of the first comparator constitute a first buffer comparator, and the third input terminal, the fourth input terminal and the second output terminal of the first comparator constitute a second buffer comparator; The first input terminal is connected to the current pulse acquisition unit, and is used to input the first output voltage to the first comparator through the first input terminal; The second input terminal, the first output terminal, and the fourth input terminal share a common ground, so that the fourth input terminal receives the first output voltage; The third input terminal is connected to the first threshold voltage, and the second output terminal is connected to the resistance value adjustment unit, and is used to compare the first output voltage with the first threshold voltage and output the control signal according to the comparison result.

3. The multi-platform voltage regulation circuit according to claim 1, wherein: The resistance value adjustment unit includes: a digital potentiometer; The first end of the digital potentiometer is connected to the voltage comparison unit, the second end of the digital potentiometer is connected to the pulse generation unit, and the resistance output end of the digital potentiometer is connected to the voltage dividing unit; The first end of the digital potentiometer is used to receive the control signal; The second end of the digital potentiometer is used to receive the pulse signal; The resistance output end is used to adjust and output the output resistance according to the control signal under the drive of the pulse signal.

4. The multi-platform voltage regulation circuit according to claim 3, wherein: The voltage divider unit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor, wherein the first resistor is connected in parallel with the output resistor and then in series with the second resistor to form a first branch, the third resistor, the fourth resistor, and the fifth resistor are connected in series at the output end of the PFC correction circuit, and the first branch is connected in parallel with the fifth resistor and then connected to the PFC control unit; The first resistor, the second resistor, the third resistor, the fourth resistor and the fifth resistor are used to adjust the magnitude of the divided voltage according to the magnitude of the output resistor, and transmit the divided voltage to the PFC control unit.

5. The multi-platform voltage regulation circuit according to claim 1, wherein: The PFC control unit includes: a second comparator, a first end of the second comparator is connected to the voltage dividing unit, and a second end of the second comparator is connected to the voltage adjusting unit; The first terminal of the second comparator is used to receive the divided voltage; The second terminal of the second comparator is used to output the width modulation signal according to the divided voltage and the second threshold voltage.

6. The multi-platform voltage regulation circuit according to claim 1, wherein: The voltage adjustment unit includes: a sixth resistor, an eighth resistor, and an insulated gate field effect transistor, the eighth resistor being connected between the sixth resistor, a first end of the insulated gate field effect transistor, and the PFC control unit, and a second end of the insulated gate field effect transistor and a third end of the insulated gate field effect transistor being connected to the PFC correction circuit; The eighth resistor is used to transmit the width modulation signal to the first end of the insulated gate field effect transistor; The insulated gate field effect transistor is used to be turned on according to the width modulation signal and determine the conduction time, and adjust the output voltage of the PFC correction circuit according to the conduction time.

7. The multi-platform voltage regulation circuit according to claim 1, wherein: The current pulse acquisition unit includes: a first diode, a second diode, a third diode, a seventh resistor, and a transformer, one winding of the transformer is connected to the output end of the PFC correction circuit, one end of the other winding of the transformer is connected to the seventh resistor and then grounded, and the other end of the other winding of the transformer is grounded, the first diode, the second diode, and the seventh resistor are connected in parallel, the cathode of the first diode and the anode of the second diode are connected to the anode of the third diode, and the cathode of the third diode is connected to the voltage comparison unit; The transformer is configured to obtain the output current of the DC-DC charging circuit through one winding of the transformer and transmit the output current of the DC-DC charging circuit to the other winding of the transformer; The first diode and the second diode are used to absorb the high voltage and high output current generated when the DC-DC charging circuit has an output short circuit or overcurrent; The third diode is used to detect the output current of the DC-DC charging circuit and output the output current pulse width.

8. The multi-platform voltage regulation circuit according to claim 1, wherein: The pulse generating unit includes: a low frequency oscillator, wherein the pulse output terminal of the low frequency oscillator is connected to the resistance value adjusting unit; The low-frequency oscillator is used to output the pulse signal to the resistance value adjustment unit.

9. A universal multi-input universal AC-DC charging device, characterized in that: include: At least one AC-DC input circuit, the PFC correction circuit, and the multi-platform voltage adjustment circuit according to any one of claims 1 to 8; The at least one AC-DC input circuit is connected to the PFC correction circuit, and the multi-platform adaptable voltage adjustment circuit is connected to the PFC correction circuit; The AC-DC input circuit is used to connect to the mains, convert AC-DC power after obtaining AC power to obtain pulsed DC power, and send the pulsed DC power to the PFC correction circuit; The PFC correction circuit is configured to output DC power to the DC-DC charging circuit by adjusting the power factor of the pulsed DC power; The multi-platform adaptable voltage adjustment circuit is used to adjust the voltage of the output DC power of the PFC correction circuit according to the output current of the DC-DC charging circuit.

10. An electric vehicle charging system, characterized in that: include: The universal multi-input universal AC-DC charging device and the DC-DC charging device as described in claim 9, wherein the DC-DC charging device includes the DC-DC charging circuit, and the universal multi-input universal AC-DC charging device is connected to the DC-DC charging device; The universal multi-input universal AC-DC charging device is used to connect to the mains, obtain AC power, perform AC-DC conversion and power factor correction on the AC power, and then obtain the output DC power, and send the output DC power to the DC-DC charging device; The DC-DC charging device is used to charge the electric vehicle according to the output DC power.

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