Voltage regulation circuit adapted to multiple platforms, charging equipment and system

Abstract

The invention provides a voltage regulation circuit, charging equipment and system suitable for multiple platforms. The voltage regulation circuit is provided with a current pulse acquisition unit, a voltage comparison unit, a resistance value regulation unit, a PFC control unit, a pulse generation unit, a voltage division unit and a voltage regulation unit. A current pulse acquisition unit is connected with a PFC correction circuit and a voltage comparison unit, the voltage comparison unit is further connected with a resistance value adjustment unit, the resistance value adjustment unit is further connected with a PFC control unit through a voltage division unit, a pulse generation unit is connected with the resistance value adjustment unit, and the PFC control unit is connected with the voltage adjustment unit. The pulse width of the output current of the DC-DC charging circuit is acquired, the output voltage of the PFC correction circuit is adjusted according to the duty ratio reflected by the pulse width of the output current, the duty ratio is adjusted, and the charging efficiency and the safety coefficient are improved.

Description

Technical Field

[0001] This application relates to the technical field of electric vehicle charging, and particularly to a voltage adjustment circuit, a charging device, and a system adapted to multiple platforms. Background Art

[0002] An electric vehicle is a clean, efficient, and sustainable means of transportation powered by an on-vehicle power source and driven by an electric motor. Since its power source is electricity, it can achieve zero emissions or extremely low emissions and has little impact on the environment. Therefore, electric vehicles have developed rapidly in recent years.

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

[0004] Currently, the electric vehicle charging platform includes two voltage levels of 400V and 800V. When switching between the two voltage levels using a DC-DC charging device, since the charging voltage of the electric vehicle is different, but the output voltage of the PFC correction circuit is fixed, the duty cycle of the switching pulse will change, thereby reducing the charging efficiency and charging reliability.

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

[0006] This application provides a voltage adjustment circuit, a charging device, and a system adapted to multiple platforms to solve the technical problems mentioned in the background art.

[0007] In a first aspect, this application provides a voltage adjustment circuit adapted to multiple platforms, which is applied to a PFC correction circuit. The PFC correction circuit is connected to a DC-DC charging circuit, and the PFC correction circuit is used to output direct current with a first voltage value to the DC-DC charging circuit. The voltage adjustment circuit adapted to multiple platforms includes: A current pulse acquisition unit, a voltage comparison unit, a resistance value adjustment unit, a PFC control unit, a pulse generation unit, a voltage division unit, and a 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 also connected to the PFC control unit through the voltage division unit. The pulse generation unit is connected to the resistance value adjustment unit. The PFC control unit is connected to the voltage adjustment unit; The current pulse acquisition unit is configured 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 corresponding first output voltage of the DC-DC charging circuit according to the output current pulse width, and output a control signal to the resistance value adjustment unit 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; The pulse generation unit is configured to output a pulse signal to the resistance value adjustment unit, and the pulse signal is used to drive the resistance value adjustment 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 under the drive of the pulse signal; The voltage division 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 a second threshold voltage; The voltage adjustment unit is configured to control and adjust the voltage of the output direct current 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.

[0008] Optionally, the voltage comparison unit includes: a first comparator, where a first input terminal, a second input terminal and a first output terminal inside the first comparator form a first buffer comparator, and a third input terminal, a fourth input terminal and a second output terminal inside the first comparator form a second buffer comparator; The first input terminal is connected to the current pulse acquisition unit, and is configured 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 are grounded together, and are configured to enable the fourth input terminal to receive 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 configured to compare the first output voltage and the first threshold voltage, and output the control signal according to the comparison result.

[0009] Optionally, the resistance value adjustment unit includes: a digital potentiometer; A first end of the digital potentiometer is connected to the voltage comparison unit, a second end of the digital potentiometer is connected to the pulse generation unit, and a resistance output end of the digital potentiometer is connected to the voltage division unit; The first end of the digital potentiometer is configured to receive the control signal; The second end of the digital potentiometer is configured to receive the pulse signal; The resistance output end is configured to adjust and output the output resistance under the drive of the pulse signal according to the control signal.

[0010] Optionally, the voltage division unit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor. The first resistor is connected in parallel with the output resistor and then connected 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. 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 configured to adjust the magnitude of the voltage division voltage according to the magnitude of the output resistance and deliver the voltage division voltage to the PFC control unit.

[0011] Optionally, the PFC control unit includes: a second comparator. A first end of the second comparator is connected to the voltage division unit, and a second end of the second comparator is connected to the voltage adjustment unit; The first end of the second comparator is configured to receive the voltage division voltage; The second end of the second comparator is configured to output the pulse width modulation signal according to the voltage division voltage and the second threshold voltage.

[0012] Optionally, the voltage adjustment unit includes: a sixth resistor, an eighth resistor, and an insulated gate field effect transistor. The eighth resistor is connected between the sixth resistor, a first end of the insulated gate field effect transistor, and the PFC control unit. A second end and a third end of the insulated gate field effect transistor are connected to the PFC correction circuit; The eighth resistor is configured to deliver the pulse width modulation signal to the first end of the insulated gate field effect transistor; The insulated gate field effect transistor is configured to conduct according to the pulse width modulation signal and determine the conduction duration, and adjust the output voltage of the PFC correction circuit through the conduction duration.

[0013] Optionally, 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 terminal 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 and the second diode are connected in parallel with the seventh resistor. 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 transfer the output current of the DC-DC charging circuit to the other winding of the transformer; The first diode and the second diode are configured to absorb the high-voltage large output current generated when the DC-DC charging circuit has an output short circuit or overcurrent; The third diode is configured to detect the output current of the DC-DC charging circuit and output the pulse width of the output current.

[0014] Optionally, the pulse generation unit includes: a low-frequency oscillator, and the pulse output terminal of the low-frequency oscillator is connected to the resistance value adjustment unit; The low-frequency oscillator is configured to output the pulse signal to the resistance value adjustment unit.

[0015] In a second aspect, the present application provides a general multi-input general AC-DC charging device, including: at least one AC-DC input circuit, the PFC correction circuit, and the multi-platform adaptable voltage adjustment circuit according to any one of the first aspect; 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 configured to be connected to the mains power, convert the obtained alternating current into pulsed direct current after AC-DC conversion, and send the pulsed direct current to the PFC correction circuit; The PFC correction circuit is configured to output direct current to the DC-DC charging circuit by adjusting the power factor of the pulsed direct current; The multi-platform adaptable voltage adjustment circuit is configured to adjust the voltage of the direct current output by the PFC correction circuit according to the output current of the DC-DC charging circuit.

[0016] 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, 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 be connected to the mains power, obtain alternating current, perform AC-DC conversion and power factor correction to obtain the output direct current, and send the output direct current to the DC-DC charging device; The DC-DC charging device is used to charge an electric vehicle according to the output direct current.

[0017] The voltage adjustment circuit, charging device and system adaptable to multiple platforms provided by the present application are provided with a current pulse acquisition unit, a voltage comparison unit, a resistance value adjustment unit, a PFC control unit, a pulse generation unit, a voltage division unit and a 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 through the voltage division 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 acquisition of the output current pulse width of the DC-DC charging circuit is realized, and the output voltage of the PFC correction circuit is adjusted according to the duty cycle reflected by the output current pulse width, so as to adjust the duty cycle, improve the charging efficiency and safety factor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a structural diagram of a voltage adjustment circuit adaptable to multiple platforms provided by an embodiment of the present application; Figure 2 It is a partial circuit diagram of a voltage adjustment circuit adaptable to multiple platforms provided by an embodiment of the present application; Figure 3 It is a partial circuit diagram of a voltage adjustment circuit adaptable to multiple platforms provided by another embodiment of the present application; Figure 4 It is a structural schematic diagram of a universal multi-input universal AC-DC charging device provided by an embodiment of the present application; Figure 5Schematic diagram of the structure of an electric vehicle charging system provided by an embodiment of the present application. Detailed implementation manners

[0020] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts also belong to the scope of protection of the present application.

[0021] When charging an electric vehicle, a DC-DC charging device is required. An efficient phase-shifted resonant full-bridge width modulation control circuit is adopted in the DC-DC charging device. When the duty cycle of the switching pulse of this circuit is relatively large, the recovery time of the transformer is insufficient, resulting in hysteresis heating, reducing the conversion efficiency and reliability; when the duty cycle of the switching pulse is relatively small, it causes a very large peak current of the power tube, making the power tube heat up, reducing the conversion efficiency and reliability.

[0022] Moreover, the electric vehicle charging platform includes two voltage levels of 400V and 800V. When using the DC-DC charging device to switch between the two voltage levels, since the charging voltage of the electric vehicle is different, but the output voltage of the PFC correction circuit is fixed, therefore, it will cause the duty cycle of the switching pulse to change, thereby reducing the charging efficiency and charging reliability.

[0023] Therefore, it is necessary to adjust the duty cycle of the switching pulse in the DC-DC charging device, which improves the charging efficiency and safety factor.

[0024] Therefore, the present application proposes a voltage adjustment circuit, a charging device and a system adaptable to multiple platforms. By collecting the output current pulse width of the DC-DC charging circuit, and then comparing the output current pulse width with a threshold voltage set according to the target duty cycle, the size of the duty cycle corresponding to the output current pulse width is determined according to the comparison result. When the duty cycle is relatively small, it indicates that the voltage value of the output voltage of the PFC correction circuit is relatively large. At this time, the voltage value of the output voltage of the PFC correction circuit is adjusted downwards; when the duty cycle is relatively large, it indicates that the voltage value of the output voltage of the PFC correction circuit is relatively small. At this time, the voltage value of the output voltage of the PFC correction circuit is adjusted upwards, realizing the adjustment of the voltage value of the output voltage of the PFC correction circuit, thereby realizing the adjustment of the duty cycle and improving the charging efficiency and safety factor.

[0025] Figure 1The structural diagram of a voltage regulation circuit adaptable to multiple platforms provided by an embodiment of the present application. Among them, the voltage regulation circuit 100 adaptable to multiple platforms is applied to the PFC correction circuit 200, and the PFC correction circuit is connected to the DC-DC charging circuit 300. The PFC correction circuit 200 is used to output direct current with a first voltage value to the DC-DC charging circuit 300.

[0026] As Figure 1 shown, the voltage regulation circuit 100 adaptable 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 division 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. 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 through the voltage division 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; The current pulse acquisition unit 110 is used to collect the output current pulse width of the DC-DC charging circuit and send the output current pulse width to the voltage comparison unit 120; The voltage comparison unit 120 is used to obtain the corresponding first output voltage of the DC-DC charging circuit according to the output current pulse width, and output a control signal to the resistance value adjustment unit 130 according to the first output voltage and the first threshold voltage. The first threshold voltage is determined according to the target duty cycle corresponding to the DC-DC charging circuit; The pulse generation unit 150 is used to output a pulse signal to the resistance value adjustment unit 130, and the pulse signal is used to drive the resistance value adjustment unit 130 to adjust the output resistance; 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; The voltage division unit 160 is used to output a divided voltage to the PFC control unit 140 according to the output resistance value; The PFC control unit 140 is used to send a pulse width modulation signal to the voltage adjustment unit 170 according to the divided voltage and the second threshold voltage; The voltage adjustment unit 170 is used to control and adjust the voltage of the output direct current of the PFC correction circuit according to the pulse width modulation signal, so that the duty cycle of the DC-DC charging circuit is the target duty cycle.

[0027] In this embodiment, when charging an electric vehicle, the DC-DC charging circuit adopts a high-efficiency phase-shifted resonant full-bridge width modulation control circuit to adjust the voltage and current. Moreover, since the PFC correction circuit is connected to the DC-DC charging circuit and the charging circuit forms a loop, the output current pulse width of the DC-DC charging circuit can be collected by the current pulse acquisition unit 110 according to the PFC correction circuit.

[0028] The voltage adjustment unit 170 is connected to the output end of the PFC correction circuit, and adjusts the voltage of the direct current output by the PFC correction circuit by controlling the conduction duration of the PFC correction circuit.

[0029] The working principle of the circuit is as follows: When the DC-DC charging circuit charges an electric vehicle and the direct current required for charging the electric vehicle is adjusted, the output voltage of the DC-DC charging circuit also changes. For example, when the output voltage of the DC-DC charging circuit changes from a large voltage to a small voltage, at this time, the output voltage of the PFC correction circuit remains unchanged, which will cause the duty cycle of the high-efficiency phase-shifted resonant full-bridge width modulation control circuit to decrease. In this way, when the output voltage of the PFC correction circuit remains unchanged, the output voltage of the DC-DC charging circuit can be adjusted from a large voltage to a small voltage. However, the decrease in the duty cycle will cause a large peak current in the power tube, resulting in the power tube heating up and reducing the charging efficiency and safety.

[0030] In this embodiment, the output current pulse width of the DC-DC charging circuit is collected in real time by the current pulse acquisition unit 110, and the duty cycle can be reflected by the output current pulse width. Therefore, when the duty cycle changes, the output current pulse width also changes accordingly, so that the change in the duty cycle can be detected in real time and promptly.

[0031] When the current pulse acquisition unit 110 collects the output current pulse width, it sends the output current pulse width to the voltage comparison unit 120. The voltage comparison unit 120 obtains the corresponding first output voltage of the DC-DC charging circuit according to the output current pulse width, denoted as the PS voltage. The PS voltage is compared with the first threshold voltage, denoted as the VR1 voltage. Among them, 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, and the target duty cycle is the duty cycle corresponding to the efficient operation of the high-efficiency phase-shifted resonant full-bridge width modulation control circuit and better charging efficiency. Therefore, by comparing the PS voltage with the VR voltage, it can be determined whether the duty cycle of the collected high-efficiency phase-shifted resonant full-bridge width modulation control circuit is the target duty cycle, and adjustment can be made when it is not the target duty cycle.

[0032] Since the output voltage of the DC-DC charging circuit is adjusted from a large voltage to a small voltage, the duty cycle decreases. 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 at a high potential.

[0033] After receiving the high potential, each time the resistance value adjustment unit 130 receives the pulse signal transmitted by the pulse generation unit 150, it stepwise increases the resistance Rw to increase the resistance value of the resistance Rw.

[0034] The increase in the resistance value of the resistance Rw causes the divided voltage output by the voltage dividing unit 160 to increase. Among them, the divided voltage is denoted as the VS voltage. Since the voltage dividing unit 160 is connected to the PFC control unit 140, the PFC control unit 140 receives the change in the VS voltage and compares the VS voltage with the second threshold voltage. Among them, the second threshold voltage is half of the first threshold voltage and is denoted as the VR2 voltage. At this time, the VS voltage should be less than the VR2 voltage. Therefore, the pulse width of the pulse width modulation signal sent by the PFC control unit 140 to the voltage adjustment unit 170 is a narrow pulse width.

[0035] The pulse width of the pulse width modulation signal is used to control the conduction duration of the PFC correction circuit. The longer the conduction duration, the greater the output voltage. Therefore, when the pulse width modulation signal is a narrow pulse width signal, the conduction duration of the PFC correction circuit is shorter. Therefore, the voltage of the output direct current is adjusted smaller, thereby increasing the duty cycle of the high-efficiency phase-shifted resonant full-bridge pulse width modulation control circuit.

[0036] When the output voltage of the DC-DC charging circuit is adjusted from a small voltage to a large voltage, its working principle can be referred to the above text and will not be elaborated here.

[0037] In this embodiment, by setting the current pulse acquisition unit 110, voltage comparison unit 120, resistance value adjustment unit 130, PFC control unit 140, pulse generation unit 150, voltage dividing unit 160, and voltage adjustment unit 170; 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 also connected to the resistance value adjustment unit 130. The resistance value adjustment unit 130 is also connected to the PFC control unit 140 through the voltage dividing 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. The acquisition of the output current pulse width of the DC-DC charging circuit is realized, and the output voltage of the PFC correction circuit is adjusted according to the duty cycle reflected by the output current pulse width to adjust the duty cycle, thereby improving the charging efficiency and safety factor.

[0038] Optionally, on the basis of the above embodiment, as Figure 2As shown in the figure, the voltage comparison unit 120 includes: a first comparator U1. The first input terminal A+, the second input terminal A−, and the first output terminal Ao inside the first comparator U1 form a first buffer comparator, and the third input terminal B+, the fourth input terminal B−, and the second output terminal Bo inside the first comparator U1 form a second buffer comparator; The first input terminal A+ is connected to the current pulse acquisition unit 110 and is used to input a first output voltage to the first comparator U1 through the first input terminal A+; The second input terminal A−, the first output terminal Ao, and the fourth input terminal are grounded, and are used to make the fourth input terminal receive the first output voltage; The third input terminal B+ is connected to a first threshold voltage, and the second output terminal Bo is connected to the resistance value adjustment unit 130 and is used to compare the first output voltage with the first threshold voltage and output a control signal according to the comparison result.

[0039] In this embodiment, the first comparator U1 may be, for example, a cache comparator. The input terminal A+, the input terminal A−, and the output terminal Ao inside the cache comparator form a first buffer comparator, and the input terminal B+, the input terminal B−, and the output terminal Bo form a second buffer comparator.

[0040] The input terminal A+ is used to receive the output current pulse width to obtain the PS voltage, and the input terminal B+ is used to receive the VR1 voltage. Among them, the input terminal A− and the output terminal Ao are connected, which can reduce the fluctuation and noise of the output signal and improve the stability and accuracy of the first buffer comparator. And the input terminal B− is also connected to the input terminal A− and the output terminal Ao. Therefore, it is equivalent to the input terminal B− receiving the PS voltage.

[0041] The second buffer comparator compares the PS voltage with the VR1 voltage and determines whether the output control signal is at a high level or a low level according to the comparison result. Among them, when the PS voltage is greater than the VR1 voltage, the control signal is at a high level; when the PS voltage is less than the VR1 voltage, the control signal is at a low level.

[0042] In this embodiment, by using a cache comparator and using the first buffer comparator and the second buffer comparator in the cache comparator, the comparison of the PS voltage and the VR1 voltage is realized, ensuring the accuracy of the comparison result.

[0043] Optionally, on the basis of the above embodiment, as Figure 2 shown, the resistance value adjustment unit 130 includes: a digital potentiometer U2; The first end of the digital potentiometer U2 is connected to the voltage comparison unit 120, the second end of the digital potentiometer U2 is connected to the pulse generation unit 150, and the resistance output end of the digital potentiometer U2 is connected to the voltage division unit 160; The first end of the digital potentiometer U2 is used to receive the control signal; The second terminal of the digital potentiometer U2 is used to receive a pulse signal; The resistance output terminal is used to adjust and output a resistance under the drive of a pulse signal according to a control signal.

[0044] In this embodiment, the pulse generation unit 150 is used to output a pulse square wave. For example, a 10HZ square wave is output. The digital potentiometer U2 is used to output an output resistance Rw with adjustable resistance. When the digital potentiometer U2 receives a control signal, when it receives a 10HZ square wave once, it adjusts the resistance value of the output resistance Rw. Specifically, when the control signal is at a high potential, the output resistance Rw steps up, and when the control signal is at a low potential, the output resistance Rw steps down to achieve resistance value adjustment.

[0045] Optionally, on the basis of the above embodiment, as Figure 2 shown, the voltage dividing 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 connected 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 then connected to the PFC control unit 140; 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 magnitude of the divided voltage according to the magnitude of the output resistance and deliver the divided voltage to the PFC control unit 140.

[0046] In this embodiment, in terms of circuit structure, the output resistor Rw is connected in parallel with the first resistor R1, and then connected 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 connected in parallel with the PFC correction circuit. Moreover, 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.

[0047] The working principle of the voltage dividing unit 160 is as follows: when the resistance value of the output resistor Rw increases, the resistance value of the parallel connection of the output resistor Rw and the first resistor R1 decreases, so that the resistance value of the branch formed by the output resistor Rw, the first resistor R1, and the second resistor R2 decreases, thereby increasing the resistance value of the parallel connection of the branch formed by the output resistor Rw, the first resistor R1, and the second resistor R2 and the fifth resistor R5, and thus increasing the voltage value of the VS voltage at the connection point of the parallel connection of the branch formed by the output resistor Rw, the first resistor R1, and the second resistor R2 and the fifth resistor R5. In this way, the VS voltage input to the PFC control unit 140 increases.

[0048] When the resistance value of the output resistor Rw decreases, the working process refers to the above text and will not be elaborated here.

[0049] In this embodiment, by connecting the output resistor Rw in parallel with the first resistor R1 in the voltage dividing unit 160, the purpose of adjusting the VS voltage according to the resistance value of the output resistor Rw is achieved.

[0050] Optionally, on the basis of the above embodiment, as Figure 2 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 adjustment unit 170; The first end of the second comparator U3 is used to receive the divided voltage; The second end of the second comparator U3 is used to output a pulse width modulation signal according to the divided voltage and the second threshold voltage.

[0051] In this embodiment, the second comparator U3 can be a device with a comparator function, and a second threshold voltage, that is, the VR2 voltage, is embedded in the second comparator U3. After receiving the VS voltage, the VS voltage is compared with the VR2 voltage. Among them, when the VS voltage is greater than the VR2 voltage, the second comparator U3 sends a pulse width modulation signal with a wide pulse width to the voltage adjustment unit 170; when the VS voltage is less than the VR2 voltage, the second comparator U3 sends a pulse width modulation signal with a narrow pulse width to the voltage adjustment unit 170.

[0052] In this embodiment, by setting the second comparator U3 to compare the VS voltage with the VR2 voltage and output a pulse width modulation signal with a corresponding pulse width according to the comparison result, the control of the conduction duration of the PFC correction circuit is achieved.

[0053] Optionally, on the basis of the above embodiment, as Figure 2 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 and the third end of the insulated gate field effect transistor are connected to the PFC correction circuit; The eighth resistor R8 is used to deliver the pulse width modulation signal to the first end of the insulated gate field effect transistor.

[0054] The insulated gate field effect transistor is used to conduct according to the pulse width modulation signal, determine the conduction duration, and adjust the output voltage of the PFC correction circuit through the conduction duration.

[0055] In this embodiment, the insulated gate field effect transistor can be, for example, an insulated enhanced N-MOS transistor M. Among them, the gate of the N-MOS transistor M is connected to the PFC control unit 140 and grounded through the sixth resistor R6, and the drain and source of the N-MOS transistor M are connected to the PFC control unit 140.

[0056] 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 through the eighth resistor R8. After the gate of the N-MOS transistor M receives the width modulation signal, the N-MOS transistor M conducts, and its conduction duration is controlled by the pulse width of the width modulation signal. When the N-MOS transistor M conducts, the inductor L1 absorbs energy. When the N-MOS transistor M disconnects, the inductor L1 outputs energy, that is, the output voltage. Among them, the more energy absorbed by the inductor L1, the larger the output voltage. Therefore, the longer the conduction duration of the N-MOS transistor M, the larger the output voltage. Therefore, by adjusting the conduction duration of the N-MOS transistor M, the adjustment of the output voltage of the PFC correction circuit is realized.

[0057] Optionally, on the basis of the above embodiments, as Figure 3 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 side winding of the transformer CS1 is connected to the output terminal of the PFC correction circuit. One end of the other side winding of the transformer CS1 is connected to the seventh resistor R7 and then grounded, and the other end of the other side winding of the transformer CS1 is grounded. The first diode D1 and the second diode D2 are connected in parallel with the seventh resistor R7. 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, and the cathode of the third diode D3 is connected to the voltage comparison unit 120 (not shown in the figure); The transformer CS1 is used to obtain the output current of the DC-DC charging circuit through one side winding of the transformer CS1 and transfer the output current of the DC-DC charging circuit to the other side winding of the transformer CS1; The first diode D1 and the second diode D2 are used to absorb the high-voltage large output current generated when the DC-DC charging circuit has an output short circuit or overcurrent; The third diode D3 is used to detect the output current of the DC-DC charging circuit and output the current pulse width.

[0058] In this embodiment, since there are other circuits connected between the current pulse acquisition unit 110 and other units in the actual circuit, for the convenience of description, the current pulse acquisition unit 110 is shown in Figure 3 .

[0059] The DC-DC charging circuit is connected between the output terminal A and the output terminal B of the PFC correction circuit. Among them, one side winding of the transformer CS1 constitutes a loop from the output terminal A to the output terminal B of the PFC correction circuit. Therefore, the output current pulse width can be collected through this side winding and then transmitted to the third diode D3 through the other side winding of the transformer CS1.

[0060] Among them, the seventh resistor R7 is used to avoid short - circuiting the two ends of the other winding of the transformer CS1. The first diode D1 and the second diode D2 are high - conduction - voltage - drop diodes and are reverse - paralleled, which can absorb the high - voltage large output current generated when the DC - DC charging circuit has an output short - circuit or over - current. The third diode D3 is a low - conduction - voltage - drop diode, and outputs the current pulse width.

[0061] In this embodiment, the current pulse acquisition unit 110 composed of the first diode D1, the second diode D2, the third diode D3, the seventh resistor R7 and the transformer CS1 not only realizes the isolation between the current pulse acquisition unit 110 and the DC - DC charging circuit through the transformer CS1, but also realizes the acquisition of the output current pulse width, thereby realizing the adaptive adjustment of the output voltage of the PFC correction circuit according to the change of the output voltage of the DC - DC charging circuit.

[0062] Optionally, on the basis of the above - mentioned embodiment, as Figure 2 shown, the pulse generation unit 150 includes: a low - frequency oscillator U4, and the pulse output end of the low - frequency oscillator U4 is connected to the resistance value adjustment unit 130; The low - frequency oscillator U4 is used to output a pulse signal to the resistance value adjustment unit 130.

[0063] In this embodiment, the low - frequency oscillator U4 is used to output a 10 - Hz pulse signal to the resistance value adjustment unit 130, so that the resistance value adjustment unit 130 steps - adjusts the resistance value of the output resistor Rw under the enable of the 10 - Hz pulse signal.

[0064] It should be noted that Figure 2 and Figure 3 also show other components. Among them, the component marked as R only represents a resistor and does not represent the resistance value, the component marked as C only represents a capacitor and does not represent capacitance and resistance, the component marked as L only represents an inductor and does not represent the inductive reactance. And these components do not involve the technical solution of this application, so they are not described in detail. For details, reference can be made to the prior art.

[0065] Figure 4 This is a schematic structural diagram of a general multi - input general AC - DC charging device provided by an embodiment of the present application. As Figure 4 shown, the general multi - input general 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 one of the above - mentioned embodiments; At least one AC - DC input circuit 400 is connected to the PFC correction circuit 200, and the multi - platform - adaptable voltage adjustment circuit 100 is connected to the PFC correction circuit 200; The AC-DC input circuit 400 is used to connect to the mains, convert the AC power into DC power to obtain pulsed DC power, and send the pulsed DC power to the PFC correction circuit 200; A PFC correction circuit 200, for outputting direct current to a DC-DC charging circuit by adjusting the power factor of the pulsed direct current; The voltage regulating circuit 100 adapted to multiple platforms is used for adjusting the voltage of the output DC power of the PFC correction circuit 200 according to the output current of the DC-DC charging circuit.

[0066] 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.

[0067] The PFC correction circuit 200 adjusts the power factor of the pulsed direct current, wherein the voltage of the output direct current is controlled by the voltage adjustment circuit 100 adapted to multiple platforms, so that the voltage of the direct current output by the PFC correction circuit 200 can be adjusted according to the charging voltage of the electric vehicle. The process of the voltage adjustment circuit 100 adapted to multiple platforms adjusting the voltage of the direct current output by the PFC correction circuit 200 is referred to the above embodiment, and will not be repeated here.

[0068] In this embodiment, by making the universal multi-input universal AC-DC charging device include at least one AC-DC input circuit 400, a PFC correction circuit 200 and a voltage adjustment circuit 100 adapted to multiple platforms as shown in any of the above embodiments, the voltage of the DC power output by the PFC correction circuit 200 is adjusted according to the charging voltage of the electric vehicle, so that the charging efficiency is high when charging the electric vehicle.

[0069] Figure 5 This is a schematic diagram of the structure of an electric vehicle charging system provided by an 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; The universal multi-input universal AC-DC charging device 1000 is used to connect to the mains, obtain AC power, perform AC-DC conversion and power factor correction to obtain output DC power, and send the output DC power to the DC-DC charging device 2000; The DC-DC charging device 2000 is used to charge an electric vehicle according to output DC power.

[0070] In this embodiment, the general multi-channel input general AC-DC charging device 1000 is connected to the mains power, converts the alternating current of the mains power into output direct current, and then delivers the output direct current to the DC-DC charging device 2000.

[0071] The DC-DC charging device 2000 includes a DC-DC charging circuit 300. The output direct current is delivered to the DC-DC charging circuit 300. The DC-DC charging circuit 300 rectifies, filters and processes the output direct current to obtain the direct current of the charging voltage of the load electric vehicle, and directly charges the electric vehicle.

[0072] Moreover, in the general multi-channel input general AC-DC charging device 1000, the voltage of the output direct current of the general multi-channel input general AC-DC charging device 1000 can be adjusted according to the voltage for charging the electric vehicle by the DC-DC charging circuit 300. When the electric vehicle charging system charges the electric vehicle, the voltage of the output direct current of the general multi-channel input general AC-DC charging device 1000 can be adaptively adjusted according to the charging voltage of the electric vehicle, so as to maintain a high charging efficiency during charging.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate 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, and the PFC correction circuit is used to output direct current electricity with a first voltage value to the DC-DC charging circuit. The voltage adjustment circuit adapted to multiple platforms includes: A current pulse acquisition unit, a voltage comparison unit, a resistance value adjustment unit, a PFC control unit, a pulse generation unit, a voltage division unit, and a 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 through the voltage division unit. The pulse generation unit is connected to the resistance value adjustment unit. The PFC control unit is connected to the voltage adjustment unit; The current pulse acquisition unit is configured 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 according to the output current pulse width, and output a control signal to the resistance value adjustment unit according to the first output voltage and a first threshold voltage, where the first threshold voltage is determined according to the target duty cycle corresponding to the DC-DC charging circuit; The pulse generation unit is configured to output a pulse signal to the resistance value adjustment unit, and the pulse signal is used to drive the resistance value adjustment 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 under the drive of the pulse signal; The voltage division 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 adjustment signal to the voltage adjustment unit according to the divided voltage and a second threshold voltage; The voltage adjustment unit is configured to control and adjust the voltage of the direct current electricity output by the PFC correction circuit according to the width adjustment signal, so that the duty cycle of the DC-DC charging circuit is the target duty cycle.

2. The voltage adjustment circuit adaptable to multiple platforms according to claim 1, characterized in that The voltage comparison unit includes: a first comparator. A first input terminal, a second input terminal, and a first output terminal inside the first comparator form a first buffer comparator. A third input terminal, a fourth input terminal, and a second output terminal inside the first comparator form a second buffer comparator; The first input terminal is connected to the current pulse acquisition unit and is configured 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 are grounded, and are configured to enable the fourth input terminal to receive 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 configured to compare the first output voltage and the first threshold voltage and output the control signal according to the comparison result.

3. The voltage adjustment circuit adapted to multiple platforms according to claim 1, characterized in that 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 division 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 under the drive of the pulse signal according to the control signal.

4. The voltage adjustment circuit adaptable to multiple platforms according to claim 3, characterized in that The voltage division unit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor. The first resistor is connected in parallel with the output resistance 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. 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 voltage division voltage according to the magnitude of the output resistance and deliver the voltage division voltage to the PFC control unit.

5. The voltage adjustment circuit adapted to multiple platforms according to claim 1, characterized in that The PFC control unit includes: a second comparator. The first end of the second comparator is connected to the voltage division unit, and the second end of the second comparator is connected to the voltage adjustment unit; The first end of the second comparator is used to receive the voltage division voltage; The second end of the second comparator is used to output the pulse width modulation signal according to the voltage division voltage and the second threshold voltage.

6. The voltage adjustment circuit adapted to multiple platforms according to claim 1, characterized in that The voltage adjustment unit includes: a sixth resistor, an eighth resistor, and an insulated gate field effect transistor. The eighth resistor is connected between the sixth resistor, the first end of the insulated gate field effect transistor, and the PFC control unit. The second end and the third end of the insulated gate field effect transistor are connected to the PFC correction circuit; The eighth resistor is used to deliver the pulse width modulation signal to the first end of the insulated gate field effect transistor; The insulated gate field effect transistor is used to conduct according to the pulse width modulation signal and determine the conduction duration, and adjust the output voltage of the PFC correction circuit through the conduction duration.

7. The voltage adjustment circuit adaptable to multiple platforms according to claim 1, characterized in that, 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 and the second diode are connected in parallel with the seventh resistor. The cathode of the first diode and the anode of the second diode are connected to the anode of the third diode. The cathode of the third diode is connected to the voltage comparison unit; The transformer is used to obtain the output current of the DC-DC charging circuit through one side winding of the transformer and transfer the output current of the DC-DC charging circuit to the other side winding of the transformer; The first diode and the second diode are used to absorb the high-voltage large 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 pulse width of the output current.

8. The voltage adjustment circuit adaptable to multiple platforms according to claim 1, characterized in that, The pulse generation unit includes: a low-frequency oscillator, and a pulse output end of the low-frequency oscillator is connected to the resistance value adjustment unit; The low-frequency oscillator is used to output the pulse signal to the resistance value adjustment unit.

9. A general multi-input general AC-DC charging device, characterized in that, Comprising: At least one AC-DC input circuit, the PFC correction circuit, and the multi-platform adaptable voltage adjustment circuit according to any one of claims 1-8; 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 be connected to the mains power, convert AC power into pulsed DC power after AC-DC conversion, and send the pulsed DC power to the PFC correction circuit; The PFC correction circuit is used 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 DC power output by the PFC correction circuit according to the output current of the DC-DC charging circuit.

10. An electric vehicle charging system, characterized in that, Comprising: The general multi-input general AC-DC charging device and the DC-DC charging device according to claim 9, the DC-DC charging device includes the DC-DC charging circuit, and the general multi-input general AC-DC charging device is connected to the DC-DC charging device; The general multi-input general AC-DC charging device is used to be connected to the mains power, perform AC-DC conversion and power factor correction after obtaining AC power to 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 an electric vehicle according to the output DC power.

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