An ac / dc input compatible circuit, a power conversion module, and a vehicle
By combining control switches and modules, adaptive matching of the circuit under AC and DC inputs is achieved, solving the problem of poor circuit compatibility and improving the circuit's compatibility and power output efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- XIAN LINCHR NEW ENERGY TECH CO LTD
- Filing Date
- 2025-09-15
- Publication Date
- 2026-07-31
AI Technical Summary
Existing circuits have poor compatibility when meeting both AC and DC input requirements. Their complex structure and low DC input power also contribute to their poor compatibility.
By controlling the working state of the first switching switch, the connection mode of the switching circuit is switched to achieve adaptive matching of AC and DC voltages. The EMC module and PFC module are used for filtering and power factor control. The circuit structure is optimized by combining the soft start module and the switching switch.
While ensuring full power output, the circuit complexity was reduced, and the circuit compatibility and electromagnetic interference resistance were improved.
Smart Images
Figure CN224583080U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of charging technology, and in particular to an AC / DC input compatible circuit, a power conversion module, and a vehicle. Background Technology
[0002] Currently, DC transmission holds a core position in long-distance, large-capacity power transmission and renewable energy grid integration (wind power, solar power) due to its advantages such as no synchronization stability issues, low line losses (lower resistance losses than AC, no inductive / capacitive reactance losses), and strong asynchronous connection capabilities. AC transmission, on the other hand, leverages the convenience of voltage scaling via transformers to still dominate distributed power supply and traditional power grids. This complementarity between the two has spurred the demand for hybrid AC / DC power supply systems.
[0003] In related technologies, circuit structures that satisfy both AC and DC input are usually quite complex, requiring the separation of AC and DC through circuit output ports or conversion modules; at the same time, the DC input power of the circuit is only 1 / 3 of the AC input power, resulting in low power during DC input and thus poor circuit compatibility.
[0004] Therefore, how to reduce circuit complexity and improve circuit compatibility while meeting both AC and DC input requirements is a technical problem that urgently needs to be solved. Summary of the Invention
[0005] The main objective of this application is to provide an AC / DC input compatible circuit, a power conversion module, and a vehicle, so as to achieve the purpose of switching different connection methods of the circuit by controlling the working state of the switching switch, thereby reducing the complexity of the circuit and improving its compatibility.
[0006] To achieve the above objectives, this application provides an AC / DC input compatible circuit, including a first switching switch and an input module, an EMC module, a PFC module, and a DC bus connected in sequence. One end of the first switching switch is connected to the neutral (N) output terminal of the EMC module, and the other end is connected to the negative output terminal of the DC bus. The input module is used to acquire the input voltage; the EMC module is used to filter the input voltage; and the PFC module is used to perform power factor correction on the input voltage. The first switching switch is open when the input voltage is AC and closed when the input voltage is DC.
[0007] Optionally, the compatibility circuit further includes a soft-start module, wherein each output terminal of the EMC module is connected to an input terminal of the PFC module through the soft-start module; wherein the soft-start module includes multiple soft-start resistors and multiple soft-start switch groups corresponding to them, the soft-start switch group includes a first soft-start switch and a second soft-start switch, the first soft-start switch and the soft-start resistor are connected in series to form a soft-start branch, and the second soft-start switch is connected in parallel across the two ends of the soft-start branch.
[0008] Optionally, the PFC module includes a rectifier bridge and multiple filter units. The rectifier bridge includes multiple bridge arm input terminals that correspond one-to-one with each of the filter units. One end of each filter unit forms an input terminal of the PFC module, and the other end is connected to the corresponding bridge arm input terminal.
[0009] Optionally, the rectifier bridge includes three bridge arms arranged in parallel, and each bridge arm has an input terminal; the DC bus includes a first bus capacitor and a second bus capacitor; wherein, the first end of the first bus capacitor forms the positive output terminal of the DC bus, the second end of the first bus capacitor is connected to the midpoint of the DC bus and the second end of the second bus capacitor forms the negative output terminal of the DC bus; the two output terminals of the three bridge arms are respectively connected to the positive output terminal and the negative output terminal of the DC bus.
[0010] Optionally, the PFC module includes three filtering units, and each filtering unit includes an inductor; the first end of each inductor forms an input terminal of the PFC module, and the second end is connected to a bridge arm input terminal.
[0011] Optionally, the compatibility circuit further includes a second switching switch; the PFC module includes three filtering units, and each filtering unit includes an inductor and a capacitor; the first end of each inductor forms an input terminal of the PFC module, and the second end is connected to a bridge arm input terminal; the first end of each capacitor is connected to the first end of its corresponding inductor, and the second end is connected to the first end of the second switching switch, the second end of the second switching switch being connected to the midpoint of the DC bus; wherein, the second switching switch is used to close when the input voltage is a three-phase AC voltage to connect the capacitor to the midpoint of the DC bus.
[0012] Optionally, the rectifier bridge includes a first bridge arm, a second bridge arm, and a third bridge arm arranged in parallel, and each of the first bridge arm to the third bridge arm includes an upper half bridge and a lower half bridge; the midpoints of the first bridge arm, the second bridge arm, and the third bridge arm form the input terminals of each bridge arm; the first output terminals of the first bridge arm, the second bridge arm, and the third bridge arm are all connected to the positive output terminal of the DC bus; and the second output terminals of the first bridge arm, the second bridge arm, and the third bridge arm are all connected to the negative output terminal of the DC bus.
[0013] Optionally, the compatibility circuit further includes: a third switching switch, one end of which is connected to the N-line output terminal of the EMC module and the other end of which is connected to the input terminal of one arm of the rectifier bridge. The third switching switch is used to switch on and off according to whether the input voltage is a single-phase AC voltage or a three-phase AC voltage.
[0014] Furthermore, to achieve the above objectives, this application also provides a power conversion module, comprising: an AC / DC input compatible circuit as described in any embodiment of this application; and a bus capacitor, a transformer module, an output rectifier module, an output EMC module, and a DC output module sequentially connected to the output terminal of the AC / DC input compatible circuit; wherein, the AC / DC input compatible circuit is used to output a DC voltage; the transformer module is used to transform the DC voltage; the output rectifier module is used to rectify the transformed DC voltage; the output EMC module is used to perform electromagnetic interference processing on the rectified DC voltage; and the DC output module is used to stabilize the DC voltage.
[0015] In addition, to achieve the above objectives, this application also provides a vehicle including the power conversion module described in any embodiment of this application.
[0016] This application utilizes a first switching switch to change the connection mode of the compatible circuit according to different types of input voltages. While ensuring that the input voltage can be output at full power, it reduces the complexity of the circuit and improves the compatibility of the circuit. Attached Figure Description
[0017] Figure 1 This is one of the schematic diagrams of an AC / DC input compatible circuit according to an embodiment of this application; Figure 2 This is a second schematic diagram of an AC / DC input compatible circuit according to an embodiment of this application; Figure 3 This is a third schematic diagram of an AC / DC input compatible circuit according to an embodiment of this application; Figure 4 This is a schematic diagram of a three-phase AC charging wave generation strategy according to an embodiment of this application; Figure 5 This is a schematic diagram of a single-phase AC charging wave generation strategy according to an embodiment of this application; Figure 6 This is a schematic diagram of a DC charging wave generation strategy according to an embodiment of this application; Figure 7 This is a schematic diagram of a power conversion module structure according to an embodiment of this application; The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0019] On-Board Charger (OBC) is a vehicle-mounted charging device used to convert external AC voltage into DC voltage that can recharge the battery. An OBC includes an AC input terminal, a soft-start circuit unit, an AC-DC converter circuit, and a DC output terminal. AC or DC voltage is connected to the AC terminal, and through fuses and EMC circuits, the system automatically identifies the AC or DC voltage using hardware sampling circuitry and software algorithms upon detection.
[0020] Currently, DC transmission holds a core position in long-distance, large-capacity power transmission and renewable energy grid integration (wind power, solar power) due to its advantages such as no synchronization stability issues, low line losses (lower resistance losses than AC, no inductive / capacitive reactance losses), and strong asynchronous connection capabilities. AC transmission, on the other hand, leverages the convenience of voltage scaling via transformers to still dominate distributed power supply and traditional power grids. This complementarity between the two has spurred the demand for hybrid AC / DC power supply systems.
[0021] Due to the fundamental differences between direct current (DC) and alternating current (AC) in energy transmission, circuit design, and component characteristics, DC current maintains a constant direction (such as the constant current output from a battery) and its voltage amplitude is stable (ideally without fluctuation). In contrast, AC current changes direction periodically with time (such as a sinusoidal AC current changing direction twice per cycle), and its voltage amplitude fluctuates according to a sine / cosine law. Furthermore, DC charges move continuously in a fixed direction, with a single energy transmission path (such as from positive to negative in a conductor). AC charges, on the other hand, undergo periodic reciprocating motion in a conductor (moving forward during the positive half-cycle and backward during the negative half-cycle), and energy is transferred through the alternating conversion of electric and magnetic fields.
[0022] Therefore, in related technologies, the circuit structure that satisfies both AC and DC input in the same circuit is usually quite complex, requiring the separation of AC and DC through the circuit's external port or conversion module; at the same time, the DC input power of the circuit is only 1 / 3 of the AC input power, resulting in low power during DC input, which leads to poor circuit compatibility.
[0023] Based on this, embodiments of this application provide an AC / DC input compatible circuit, a power conversion module, and a vehicle, so as to achieve the purpose of switching different connection methods of the circuit by controlling the working state of the first switching switch, thereby reducing circuit complexity and improving circuit compatibility.
[0024] To facilitate understanding, the AC / DC input compatible circuit will be described in detail below.
[0025] Figure 1 This is one of the schematic diagrams of an AC / DC input compatible circuit structure according to an embodiment of this application.
[0026] like Figure 1 As shown, the AC / DC input compatible circuit 100 includes: a first switching switch S8 and an input module 101, an EMC module 102, a PFC module 10, and a DC bus connected in sequence. One end of the first switching switch S8 is connected to the N-line output terminal of the EMC module 102, and the other end is connected to the negative output terminal of the DC bus. The input module 101 is used to acquire the input voltage; the EMC module 102 is used to filter the input voltage; the PFC module 10 is used to perform power factor correction on the input voltage; and the first switching switch S8 is used to switch the compatible circuit between AC and DC according to the voltage type of the input voltage.
[0027] The input module 101 may be an AC input terminal corresponding to AC power. The AC input terminal may include a U-phase input terminal, a V-phase input terminal, a W-phase input terminal, and an N-phase input terminal. Correspondingly, the EMC module 102 may include a U-phase input terminal, a V-phase input terminal, a W-phase input terminal, and an N-phase input terminal to be connected to each input terminal of the input module 101 through a corresponding fuse.
[0028] After the input module 101 obtains the input voltage, it is filtered by the EMC module 102 to remove stray signals and then input to the PFC module 10 for power factor management to improve the compatible power factor.
[0029] When the input voltage is AC voltage, the AC voltage is processed by PFC module 10 and output as DC voltage, which is then output as DC through the DC bus.
[0030] In this exemplary embodiment, the DC bus may be composed of bus capacitors, which store charge to supply DC power to the downstream load.
[0031] The first switching switch S8 primarily switches on and off based on the input voltage type. Specifically, when the input voltage is AC, the first switching switch S8 is open under the control of the controller, and the AC / DC input compatible circuit is matched to the AC input. When the input voltage is DC, the first switching switch S8 is closed under the control of the controller, and the AC / DC input compatible circuit is matched to the DC input. Thus, the AC / DC input compatible circuit provided in this embodiment, through the action of the first switching switch S8, can self-match AC and DC input voltages. While ensuring full-power output of the input voltage, it reduces circuit complexity and improves circuit compatibility.
[0032] In addition, in the diagram, resistor R4 represents the load connected to the subsequent stage of the circuit.
[0033] The circuit structure and working principle of the AC / DC input compatible circuit of this embodiment will be explained in detail below with reference to the accompanying drawings.
[0034] Figure 2 This is a second schematic diagram of an AC / DC input compatible circuit according to an embodiment of this application.
[0035] like Figure 2 As shown, the AC / DC input compatible circuit may also include a soft start module 105 and a second switching switch S9. The soft start module 105 is connected between the EMC module 102 and the PFC module 10. One end of the second switching switch S9 is connected to each input terminal of the PFC module 10, and the other end is connected to the midpoint of the DC bus.
[0036] The second switching switch S9 is mainly used to optimize EMC performance. When AC power is supplied (i.e., the input voltage is three-phase AC or single-phase AC), closing the second switching switch S9 connects the capacitor in the filter unit 103 (the specific structure of the filter unit 103 can be found in the description of the following embodiments) to the midpoint of the DC bus.
[0037] In this embodiment, the first switching switch S8 and the second switching switch S9 are connected on both sides of the EMC module 102 and the output module 105 as switching switches. In this way, the EMC circuit can be reused regardless of whether it is AC input or DC input. Therefore, the circuit of this application has good anti-electromagnetic interference performance.
[0038] In this embodiment, the EMC module 102 may include a U-phase output terminal, a V-phase output terminal, and a W-phase output terminal. Correspondingly, the multiple input terminals of the PFC module 10 may include a U-phase input terminal, a V-phase input terminal, and a W-phase input terminal.
[0039] In an exemplary embodiment, each output terminal of the EMC module 102 is connected to an input terminal of the PFC module 10 via a soft start module 105. The soft start module 105 may include multiple soft start switch groups and multiple soft start resistors, with each soft start resistor corresponding to one of the multiple soft start switch groups; each soft start switch group may include a first soft start switch and a second soft start switch, with the first soft start switch and a soft start resistor connected in series to form a soft start branch, and the second soft start switch connected in parallel across the two ends of the soft start branch.
[0040] Continue to refer to Figure 2 Taking the soft-start switch group and soft-start resistor connected to the U-phase output terminal of EMC module 102 as an example, the first switch S1 is the first soft-start switch in the soft-start switch group, and the second switch S2 is the second soft-start switch in the soft-start switch group. The first switch S1 and the first resistor R1 constitute a soft-start branch.
[0041] Similarly, in the soft-start switch group connected to the V-phase output terminal of EMC module 102, the third switch S3 is the first soft-start switch, the fourth switch S4 is the second soft-start switch, and the second resistor R2 is the soft-start resistor; in the soft-start switch group connected to the W-phase output terminal of EMC module 102, the fifth switch S5 is the first soft-start switch, the sixth switch S6 is the second soft-start switch, and the third resistor R3 is the soft-start resistor.
[0042] After the controller obtains the output voltage of the EMC module 102, it controls each soft-start switch and soft-start resistor in the soft-start module 105 according to a certain timing sequence to ensure that the system starts smoothly and provides stable input conditions for subsequent charging mode recognition and power conversion, avoiding circuit impact and damage.
[0043] Figure 3 This is the third AC / DC input compatible circuit according to an embodiment of this application.
[0044] like Figure 3 As shown, the PFC module 10 may include a rectifier bridge 104 and multiple filter units 103, and the rectifier bridge 104 may include multiple bridge arm input terminals corresponding one-to-one with each filter unit 103; one end of the filter unit 103 forms an input terminal of the PFC module 10, and the other end is connected to the corresponding bridge arm input terminal.
[0045] The filter unit 103 is mainly used to filter the input voltage. In this exemplary embodiment, the filter unit 103 is mainly used to suppress high-frequency noise, that is, to prevent harmonics generated by the rectifier bridge 104 from being conducted to the input side. In other words, the filter unit 103 can block the high-frequency interference signals generated by the rectifier bridge 104, preventing them from polluting the compatible circuit. The rectifier bridge 104 is used to rectify the AC input voltage into a DC voltage for output.
[0046] In an exemplary embodiment, the filter unit 103 may consist of only an inductor, that is, each bridge arm input terminal of the rectifier bridge 104 is connected to the soft start module 105 through an inductor. In this case, one end of the inductor forms an input terminal of the filter unit 103, and the other end is connected to an input terminal of a bridge arm of the rectifier bridge 104. By setting an inductor for filtering, the current waveform of the circuit can be corrected.
[0047] In an exemplary embodiment, the filter unit 103 may further include an inductor and a capacitor. In this case, the first end of each inductor forms an input terminal of the PFC module and the second end is connected to a bridge arm input terminal. The first end of each capacitor is connected to the first end of the corresponding inductor and the second end is connected to the first end of the second switching switch S9. The second end of the second switching switch S9 is connected to the midpoint of the DC bus.
[0048] Among them, reference Figure 3 In the rectifier bridge circuit of the three-phase current bridge arm, the filter unit 103 may include a first inductor L1, a second inductor L2 and a third inductor L3, as well as a first capacitor C1, a second capacitor C2 and a third capacitor C3. The first end of the first inductor L1 is connected to the first end of the first capacitor C1, the first end of the second inductor L2 is connected to the first end of the second capacitor C2, the first end of the third inductor L3 is connected to the first end of the third capacitor C3, and the second ends of the first capacitor C1, the second capacitor C2 and the third capacitor C3 are all connected to the first end of the second switching switch S9. The second end of the second switching switch S9 is connected to the midpoint of the DC bus.
[0049] The inductor and capacitor constitute an LLC filter circuit. When the input voltage is AC, the capacitor can be connected to the midpoint of the DC bus by closing the second switching switch S9, which can improve the EMC performance of the compatible circuit.
[0050] The structure of the rectifier bridge will be described in detail below with reference to the attached diagram.
[0051] by Figure 3 Taking the three-phase six-arm rectifier bridge shown as an example, the rectifier bridge 104 includes a first arm, a second arm, and a third arm arranged in parallel, and each of the first arm to the third arm includes an upper half bridge and a lower half bridge; the midpoints of the first arm, the second arm, and the third arm form the input terminals of each arm; the first output terminal of the first arm, the first output terminal of the second arm, and the first output terminal of the third arm are all connected to the positive output terminal of the DC bus; the second output terminal of the first arm, the second output terminal of the second arm, and the second output terminal of the third arm are all connected to the negative output terminal of the DC bus.
[0052] The rectifier bridge 104 can be composed of switching transistors Q1-Q7, for example. The DC bus can include a first bus capacitor C4 and a second bus capacitor C5. The first terminal of the first bus capacitor C4 forms the positive output terminal of the DC bus, and the second terminal is connected to the midpoint of the DC bus, which is the second terminal of the second bus capacitor C5. The second terminal of the second bus capacitor C5 forms the negative output terminal of the DC bus. Switching transistors Q1 and Q5 form the first bridge arm, the midpoint of which is connected to the first inductor L1, and the first output terminal of the first bridge arm is connected to the positive output terminal of the DC bus. The first bridge arm consists of two output terminals: the second output terminal of the first bridge arm is connected to the negative output terminal of the DC bus; the second bridge arm is composed of switching transistors Q2 and Q3, with the midpoint of the second bridge arm connected to the second inductor L2, the first output terminal of the second bridge arm connected to the positive output terminal of the DC bus, and the second output terminal of the second bridge arm connected to the negative output terminal of the DC bus; the third bridge arm is composed of two output transistors Q3 and Q7, with the midpoint of the third bridge arm connected to the third inductor L3, the first output terminal of the third bridge arm connected to the positive output terminal of the DC bus, and the second output terminal of the third bridge arm connected to the negative output terminal of the DC bus.
[0053] When the input voltage is a three-phase AC voltage, the rectifier bridge 104 acts as a PFC (power factor correction) circuit. By controlling the timing of the switching transistors (such as generating waves with a 120° phase difference), it converts AC power into DC power and achieves a high power factor.
[0054] For example, when the input voltage is a three-phase AC voltage, the first switching switch S8 is kept open, and the first soft-start switches (switches S1, S3, and S5) are closed to put the AC / DC input circuit into a soft-start state. After sampling and software algorithm judgment of phase A voltage (Va), phase A current (Ia), phase B voltage (Vb), phase B current (Ib), phase C voltage (Vc), and phase C current (Ic) and there are no abnormalities, the second soft-start switches (switches S2, S4, and S6) are closed. At the same time, the second switching switch S9 is closed to connect the capacitive reactance unit (first capacitor C1, second capacitor C2, and third capacitor C3) to the DC bus to improve the EMC performance of the circuit. After completing the above operations, the AC / DC input compatible circuit enters the three-phase AC charging mode, and the software controls the rectifier bridge 104 to realize AC / DC conversion. At this time, the power is the maximum power.
[0055] Combination Figure 2 and Figure 3 In an exemplary embodiment, the AC / DC input compatible circuit may further include a third switching switch S7. One end of the third switching switch S7 is connected to the N-line output terminal of the EMC module 102, and the other end of the third switching switch S7 is connected to the input terminal of a bridge arm of the rectifier bridge 104. The third switching switch S7 is used to switch on and off according to whether the input voltage is a single-phase AC voltage or a three-phase AC voltage.
[0056] The third switching switch S7 is connected between the EMC module 102 and the rectifier bridge 104, and its main function is to switch the on / off state based on the AC type of the input AC voltage. Specifically, when the input voltage is a three-phase AC voltage, the third switching switch S7 is open under the control of the controller, ensuring that the three-phase signal is processed in a dedicated channel, reducing interference from the single-phase circuit to the three-phase system, improving signal purity and stability, and thus enhancing circuit compatibility. When the input voltage is a single-phase AC voltage, the third switching switch S7 is closed under the control of the controller. In this case, the system can still utilize part of the bridge arm of the three-phase PFC circuit in single-phase AC charging mode, avoiding the influence of electromagnetic interference that may be generated by the three-phase processing circuit on the single-phase AC signal, and ensuring the balance and efficiency of the AC / DC input compatible circuit.
[0057] For example, when the controller determines that the input voltage is a three-phase AC voltage, the controller controls the first switching switch S8 and the third switching switch S7 to open, and closes the first soft-start switch (switches S1, S3, and S5) in the soft-start module 105, so that the AC / DC input circuit enters the soft-start state. After sampling and software algorithm judgment of phase A voltage (Va), phase A current (Ia), phase B voltage (Vb), phase B current (Ib), phase C voltage (Vc), and phase C current (Ic) and there are no abnormalities, the second soft-start switch (switches S2, S4, and S6) is closed. At the same time, the second switching switch S9 is closed to connect the first capacitor C1, the second capacitor C2, and the third capacitor C3 to the DC bus to improve the EMC performance of the circuit. After completing the above operations, the AC / DC input compatible circuit enters the three-phase AC charging mode. The controller controls the PFC module 10 to realize AC / DC conversion according to the preset timing sequence. At this time, the power of the circuit is the maximum power.
[0058] Figure 4 This is a schematic diagram of a three-phase AC charging wave generation strategy according to an embodiment of this application.
[0059] like Figure 4 As shown, when the input voltage is a three-phase AC charging voltage, the rectifier bridge 104 generates a wave driving timing at a certain moment when the input AC voltage is in the positive half-cycle; when the input AC is in the positive half-cycle, the three arms of the rectifier bridge 104 generate waves at a 120° angle, and at the same time, only one set of arms generates waves. Figure 4 As shown, EPWM1A corresponds to switch Q1, EPWM1B corresponds to switch Q5, EPWM2A corresponds to switch Q2, EPWM2B corresponds to switch Q6, EPWM3A corresponds to switch Q3, and EPWM3B corresponds to switch Q7.
[0060] When the input voltage is a single-phase AC voltage, by closing the third switching switch S7, the single-phase input is adapted to a certain bridge arm (such as the third bridge arm), and other bridge arms may be idle or partially engaged (power reduced to 1 / 3).
[0061] For example, when the input voltage is a single-phase AC voltage (taking only phase A as an example), the controller controls the first switching switch S8 to open and closes the first soft-start switch S1 to put the circuit into soft-start mode. After sampling and judging by the software algorithm that there are no abnormalities in phase A voltage, phase A current, phase B voltage, phase B current, phase C voltage, and phase C current, the controller closes the second soft-start switch S2, and simultaneously closes the second switching switch S9 and the third switching switch S7. By closing the second switching switch S9, the first capacitor C1 is connected to the DC bus to improve the EMC performance of the circuit. By closing the third switching switch S7, it is connected to the midpoint of the bridge arm formed by the switching transistors Q3 and Q7. After completing the above operations, the circuit enters the single-phase AC charging mode. The controller controls the PFC module 10 to realize AC / DC conversion. At this time, the power is 1 / 3 of the maximum power.
[0062] Figure 5 This is a schematic diagram of a single-phase AC charging wave generation strategy according to an embodiment of this application.
[0063] like Figure 5 As shown, when the input voltage is single-phase AC charging, the rectifier bridge 104 generates a wave driving timing at a certain moment when the input AC voltage is in the positive half-cycle. At a certain moment, only one set of bridge arms of the rectifier bridge 104 generates a wave. EPWM1A corresponds to switch Q1, EPWM1B corresponds to switch Q5, EPWM2A corresponds to switch Q2, EPWM2B corresponds to switch Q6, EPWM3A corresponds to switch Q3, and EPWM3B corresponds to switch Q7.
[0064] When the input voltage is a DC voltage, the rectifier bridge is converted into a DC-DC converter, which boosts the DC input to the required bus voltage by simultaneously driving the switching transistors of all bridge arms.
[0065] For example, when the input voltage is DC, the controller disconnects the second switching switch S9 and the third switching switch S7, and closes the first soft-start switch (switches S1, S3, and S5) to enter soft-start mode. After sampling the A-phase voltage, A-phase current, B-phase voltage, B-phase current, C-phase voltage, and C-phase current and judging by the software algorithm that there are no abnormalities, the controller simultaneously closes the second soft-start switch (switches S2, S4, and S6) and the first switching switch S8, or closes the second soft-start switch (switches S2, S4, and S6) first and then closes the first switching switch S8 to enter DC charging mode. The software controls the switching transistors Q1 to Q7 to achieve AC / DC conversion, and the circuit power is at its maximum power at this time.
[0066] Figure 6 This is a schematic diagram of a DC charging wave generation strategy according to an embodiment of this application.
[0067] like Figure 6 As shown, during three-phase AC charging, the rectifier bridge 104 generates a wave to drive the timing at a certain moment when the DC input is applied. When the DC input is applied, the three bridge arms generate waves simultaneously. Among them, EPWM1A corresponds to switch Q1, EPWM1B corresponds to switch Q5, EPWM2A corresponds to switch Q2, EPWM2B corresponds to switch Q6, EPWM3A corresponds to switch Q3, and EPWM3B corresponds to switch Q7.
[0068] This application also provides a power conversion module. Figure 7 This is a schematic diagram of a power conversion module structure according to an embodiment of this application.
[0069] like Figure 7 As shown, the power conversion module 700 may include: an AC / DC input compatible circuit 100, and a bus capacitor C6 connected in sequence at the output terminal of the AC / DC input compatible circuit 100, a transformer module 701, an output rectifier module 702, an output EMC module 703, and a DC output module 704. The AC / DC input compatible circuit 100 is used to output DC voltage; the transformer module 701 is used to transform the DC voltage; the output rectifier module 702 is used to rectify the transformed DC voltage; the output EMC module 703 is used to process the electromagnetic interference of the rectified DC voltage; and the DC output module 704 is used to stabilize the DC voltage. The transformer module 705 may be, for example, a DC / DC circuit; the DC output module 708 may include a parallel resistor Co.
[0070] After the AC / DC input compatible circuit 100 outputs DC voltage, the output ripple is smoothed by the bus capacitor C6, and the transformer module 701 transforms the DC voltage (such as step-down, step-up, isolation, etc.). After rectification by the output rectifier module 702 and noise reduction by the output EMC module 703, the DC output module 704 inputs the DC output voltage. The DC output module 704 filters the output voltage and then inputs it to the load Ro.
[0071] Based on the above embodiments, this application also provides a vehicle that includes the power conversion module described in any of the foregoing embodiments, and correspondingly, also includes the beneficial effects described in any of the foregoing embodiments.
[0072] Based on the above embodiments, this application also provides a charging device, including the power conversion module described in any of the foregoing embodiments, and correspondingly, also includes the beneficial effects described in any of the foregoing embodiments.
[0073] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.
[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. An AC / DC input compatible circuit, characterized in that, It includes a first switching switch and an input module, an EMC module, a PFC module and a DC bus connected in sequence. One end of the first switching switch is connected to the N-line output terminal of the EMC module and the other end is connected to the negative output terminal of the DC bus. The input module is used to acquire the input voltage; The EMC module is used to filter the input voltage; The PFC module is used to perform power factor correction on the input voltage; Specifically, when the input voltage is AC voltage, the first switching switch is open; when the input voltage is DC voltage, the first switching switch is closed.
2. The circuit of claim 1, wherein, The compatibility circuit also includes a soft-start module, and each output of the EMC module is connected to an input of the PFC module through the soft-start module. The soft start module includes multiple soft start resistors and multiple soft start switch groups corresponding to them. The soft start switch group includes a first soft start switch and a second soft start switch. The first soft start switch and the soft start resistor are connected in series to form a soft start branch, and the second soft start switch is connected in parallel to both ends of the soft start branch.
3. The circuit of claim 1, wherein, The PFC module includes a rectifier bridge and multiple filter units. The rectifier bridge includes multiple bridge arm input terminals that correspond one-to-one with each of the filter units. One end of the filtering unit forms an input terminal of the PFC module, and the other end is connected to the corresponding bridge arm input terminal.
4. The circuit of claim 3, wherein, The rectifier bridge includes three bridge arms arranged in parallel, and each bridge arm has a bridge arm input terminal; The DC bus includes a first bus capacitor and a second bus capacitor. Wherein, the first end of the first bus capacitor forms the positive output terminal of the DC bus, the second end of the first bus capacitor is connected to the midpoint of the DC bus and the second end of the second bus capacitor forms the negative output terminal of the DC bus; The two output terminals of each of the three bridge arms are connected to the positive and negative output terminals of the DC bus, respectively.
5. The circuit of claim 4, wherein, The PFC module includes three filtering units, and each filtering unit includes an inductor; The first end of each inductor forms an input terminal of the PFC module, and the second end is connected to a bridge arm input terminal.
6. The circuit of claim 4, wherein, The compatibility circuit also includes a second switching switch; The PFC module includes three filtering units, and each filtering unit includes an inductor and a capacitor; The first end of each inductor forms an input terminal of the PFC module, and the second end is connected to a bridge arm input terminal. Each capacitor has its first terminal connected to the first terminal of its corresponding inductor and its second terminal connected to the first terminal of the second switching switch. The second terminal of the second switching switch is connected to the midpoint of the DC bus. The second switching switch is used to close when the input voltage is a three-phase AC voltage to connect the capacitor to the midpoint of the DC bus.
7. The circuit of claim 4, wherein, The rectifier bridge includes a first bridge arm, a second bridge arm, and a third bridge arm arranged in parallel, and each of the first bridge arm to the third bridge arm includes an upper half bridge and a lower half bridge; the midpoints of the first bridge arm, the second bridge arm, and the third bridge arm form the input terminals of each bridge arm; the first output terminals of the first bridge arm, the second bridge arm, and the third bridge arm are all connected to the positive output terminal of the DC bus; and the second output terminals of the first bridge arm, the second bridge arm, and the third bridge arm are all connected to the negative output terminal of the DC bus.
8. The circuit of claim 4, wherein, The compatible circuit also includes: The third switching switch is connected at one end to the N-line output terminal of the EMC module and at the other end to the input terminal of one arm of the rectifier bridge. The third switching switch is used to switch the on / off state according to whether the input voltage is a single-phase AC voltage or a three-phase AC voltage.
9. A power conversion module, characterized by The power conversion module includes: The AC / DC input compatible circuit according to any one of claims 1-8; and, The bus capacitor, transformer module, output rectifier module, output EMC module and DC output module are connected sequentially at the output terminal of the AC / DC input compatible circuit. The AC / DC input compatible circuit is used to output DC voltage. The transformer module is used to transform the DC voltage; The output rectifier module is used to rectify the transformed DC voltage; The output EMC module is used to process electromagnetic interference in the rectified DC voltage. The DC output module is used to stabilize the DC voltage.
10. A vehicle, characterized in that, Includes the power conversion module as described in claim 9.