Circuit for slowly starting bus capacitor voltage through LLC (Logical Link Control) during quick charging of bidirectional inversion mains supply

Abstract

The utility model discloses a circuit for slowly starting the voltage of a bus capacitor through an LLC (Logical Link Control) during quick charging of a bidirectional inversion mains supply, which comprises a DC / DC (Direct Current / Direct Current) buck-boost module, a bus capacitor and a bidirectional input / output rectifier module which are connected in sequence, and a buck-boost driving module is electrically connected with the DC / DC buck-boost module; the bidirectional input and output rectification driving module is electrically connected with the bidirectional input and output rectification module, the commercial power input module is electrically connected with the bidirectional input and output rectification module, the commercial power voltage detection module is electrically connected with the commercial power input module, and the BUS voltage detection module is electrically connected with the bus capacitor. According to the utility model, by controlling the bidirectional input / output rectifier module, the voltage of the battery is boosted and the bus capacitor is charged through the DC / DC buck-boost module, and when the voltage of the bus capacitor reaches a specified value, the commercial power input module is closed and is switched to commercial power input, so that circuits related to a current-limiting resistor and rectification are saved; and a certain volume and cost of the inverter are reduced.

Description

Technical Field

[0001] This utility model relates to the technical field of slow-start bus capacitor voltage in bidirectional inverter circuits, and in particular to a circuit that uses LLC to slow-start bus capacitor voltage during bidirectional inverter mains fast charging. Background Technology

[0002] Bidirectional inverters have a wide range of applications in the energy storage industry. They convert AC power from the grid into DC power to charge batteries, or convert DC power from batteries into AC power for output. Conventional bidirectional inverters on the market, when connected to the mains, first use a rectifier bridge, then a current-limiting resistor to charge the inverter's bus capacitor. Once the bus capacitor reaches a certain voltage, the power is switched to PFC to charge the battery. This process is overly complex and involves numerous components, increasing the inverter's manufacturing cost and overall size, hindering miniaturization. Utility Model Content

[0003] The purpose of this invention is to address the aforementioned problems by providing a circuit that uses an LLC to gradually raise the bus capacitor voltage during bidirectional inverter mains fast charging. When mains input is detected, the battery is used to power the inverter first. The low voltage of the battery is boosted to charge the bus capacitor. When the bus capacitor voltage reaches a specified value, the mains power is then connected. This saves on current-limiting resistors and rectification-related circuits, and reduces the size and cost of the inverter.

[0004] To achieve the above-mentioned objectives, the technical solution adopted by this utility model is as follows:

[0005] According to one aspect of the present invention, a circuit is provided for slowing up the bus capacitor voltage via LLC during bidirectional inverter mains fast charging, including a bus capacitor, a DC / DC step-up / step-down module, a bidirectional input / output rectifier module, a step-up / step-down drive module, a bidirectional input / output rectifier drive module, a mains input module, a mains voltage detection module, and a BUS voltage detection module;

[0006] The DC / DC step-up / step-down module, bus capacitor, and bidirectional input / output rectifier module are electrically connected in sequence.

[0007] The buck-boost drive module is electrically connected to the DC / DC buck-boost module;

[0008] The bidirectional input / output rectifier drive module is electrically connected to the bidirectional input / output rectifier module;

[0009] The mains power input module is electrically connected to the bidirectional input / output rectifier module;

[0010] The mains voltage detection module is electrically connected to the mains input module;

[0011] The BUS voltage detection module is electrically connected to the bus capacitor.

[0012] Preferably, the DC / DC buck-boost module includes a battery connection terminal, a fuse, a transformer, an NMOS complementary circuit, a resonant capacitor, and a buck-boost bridge rectifier circuit;

[0013] The battery connection terminal is electrically connected to the fuse, the fuse is electrically connected to the low-voltage side of the transformer, the NMOS complementary circuit is electrically connected to the low-voltage side of the transformer, the high-voltage side of the transformer is electrically connected to the step-up / step-down bridge rectifier circuit through the resonant capacitor, and the step-up / step-down bridge rectifier circuit is electrically connected to the bus capacitor.

[0014] Preferably, the bidirectional input / output rectifier module includes an input / output bridge rectifier circuit, which is electrically connected to the bus capacitor.

[0015] Preferably, the buck-boost drive module includes a first buck-boost drive chip and a second buck-boost drive chip, and the first buck-boost drive chip and the second buck-boost drive chip are electrically connected to the buck-boost bridge rectifier circuit, respectively.

[0016] Preferably, the bidirectional input / output rectifier driver module includes a first bidirectional input / output rectifier driver chip and a second bidirectional input / output rectifier driver chip, and the first bidirectional input / output rectifier driver chip and the second bidirectional input / output rectifier driver chip are electrically connected to the input / output bridge rectifier circuit, respectively.

[0017] Preferably, the mains input module includes a relay and a mains input control circuit. The relay is connected to the L terminal and N terminal of the mains power supply, respectively. The mains input control circuit is electrically connected to the relay and connected to a microcontroller.

[0018] Preferably, the mains voltage detection module includes a first operational amplifier, a second operational amplifier, and a third operational amplifier;

[0019] The non-inverting input of the first operational amplifier is electrically connected to the L terminal of the mains power supply, and the inverting input of the first operational amplifier is electrically connected to the N terminal of the mains power supply. The non-inverting input of the second operational amplifier is electrically connected to the output terminal of the first operational amplifier, and the inverting input of the second operational amplifier is electrically connected to the output terminal of the second operational amplifier. The output terminal of the second operational amplifier is connected to a microcontroller. The inverting input of the third operational amplifier is electrically connected to the output terminal of the first operational amplifier, and the non-inverting input of the third operational amplifier is grounded through a resistor. The output terminal of the third operational amplifier is connected to a microcontroller.

[0020] Preferably, the BUS voltage detection module includes a BUS voltage detection operational amplifier, the non-inverting terminal of which is electrically connected to the positive terminal of the bus capacitor, and the inverting terminal of which is electrically connected to the negative terminal of the bus capacitor.

[0021] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0022] This invention controls a bidirectional input / output rectifier module to boost the battery voltage and charge the bus capacitor via a DC / DC buck-boost module. When the bus capacitor voltage reaches a specified value, the mains input module is then engaged to switch to mains input. This saves on current-limiting resistors and rectification-related circuitry, reducing the inverter's size and cost. Attached Figure Description

[0023] Figure 1 This is a circuit diagram of the bus capacitor, DC / DC step-up / step-down module, and bidirectional input / output rectifier module of this utility model.

[0024] Figure 2 This is the circuit schematic diagram of the buck-boost drive module of this utility model;

[0025] Figure 3 This is the circuit schematic diagram of the bidirectional input / output rectifier drive module of this utility model;

[0026] Figure 4 This is the circuit schematic diagram of the mains power input module of this utility model;

[0027] Figure 5 This is the circuit diagram of the mains voltage detection module of this utility model;

[0028] Figure 6 This is the circuit schematic diagram of the BUS voltage detection module of this utility model. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided with reference to the accompanying drawings and preferred embodiments. However, it should be noted that many details listed in the specification are merely to provide the reader with a thorough understanding of one or more aspects of the utility model, and these aspects can be achieved even without these specific details.

[0030] Please see Figure 1-6 This utility model provides a circuit for gradually raising the bus capacitor voltage via LLC during bidirectional inverter mains fast charging. The technical solution is as follows:

[0031] A circuit for bidirectional inverter AC fast charging via LLC-based bus capacitor voltage ramp-up includes a bus capacitor, a DC / DC step-up / step-down module, a bidirectional input / output rectifier module, a step-up / step-down driver module, a bidirectional input / output rectifier driver module, an AC input module, an AC voltage detection module, and a BUS voltage detection module. The DC / DC step-up / step-down module, bus capacitor, and bidirectional input / output rectifier module are electrically connected in sequence.

[0032] Specifically, such as Figure 1 As shown, the DC / DC step-up / step-down module includes a battery connection terminal, a fuse, a transformer, an NMOS complementary circuit, a resonant capacitor, and a step-up / step-down bridge rectifier circuit. The battery connection terminal is connected in series with the fuse. In this embodiment, the fuse consists of four fuses connected in parallel: fuse F1, fuse F2, fuse F3, and fuse F4. These four fuses are connected in parallel to each other and then connected to the transformer. Two polarized capacitors, C26 and C27, are placed between the fuses and the transformer. The positive terminals of the two capacitors are connected together and then connected between the fuses and the transformer, while the negative terminals of the two capacitors are grounded. The transformer includes a low-voltage side and a high-voltage side. The low-voltage side of the transformer is connected to the fuse and includes two sets of coils connected in parallel: coil set T4-A and coil set T4-D. Each coil set consists of two coils connected in series.

[0033] The two ends of the two parallel coil groups are respectively connected to an NMOS complementary circuit. Specifically, the NMOS complementary circuit includes a first NMOS circuit and a second NMOS circuit. The first NMOS circuit includes transistors Q13 and Q14. The gate of transistor Q13 is connected to the voltage divider node of two series resistors (resistors R57 and R60). The end of resistor R60 away from the voltage divider node is connected to the control signal COMA, and the end of resistor R57 away from the voltage divider node is grounded. A diode D30 is connected in series between the gate of transistor Q13 and the control signal COMA. The anode of diode D30 is connected to transistor Q13, and the cathode of diode D30 is connected to the control signal COMA. The source of transistor Q13 is grounded, and its drain is connected to the corresponding terminals of the two parallel coil groups. The gate of transistor Q14 is connected to the voltage divider node of two series resistors (resistors R58 and R61). The end of resistor R61 away from the voltage divider node is connected to the control signal COMA, and the end of resistor R58 away from the voltage divider node is grounded. A diode D31 is connected in series between the gate of transistor Q14 and the control signal COMA. The anode of diode D31 is connected to transistor Q14, and the cathode of diode D31 is connected to the control signal COMA. The source of transistor Q14 is grounded, and its drain is connected to the same-name terminals of two parallel coil groups.

[0034] The second NMOS circuit includes transistors Q9 and Q10. The gate of transistor Q9 is connected to a voltage divider node formed by two series resistors (R51 and R54). The end of resistor R54 furthest from the voltage divider node is connected to the control signal COMB, and the end of resistor R51 furthest from the voltage divider node is grounded. A diode D32 is connected in series between the gate of transistor Q9 and the control signal COMB. The anode of diode D32 is connected to transistor Q9, and the cathode of diode D32 is connected to the control signal COMB. The source of transistor Q9 is grounded, and its drain is connected to the opposite terminals of two parallel coil groups. The gate of transistor Q10 is connected to a voltage divider node formed by two series resistors (R52 and R55). The end of resistor R55 furthest from the voltage divider node is connected to the control signal COMB, and the end of resistor R52 furthest from the voltage divider node is grounded. A diode D33 is connected in series between the gate of transistor Q10 and the control signal COMB. The anode of diode D33 is connected to transistor Q10, and the cathode of diode D33 is connected to the control signal COMB. The source of transistor Q10 is grounded, and its drain is connected to the opposite terminals of two parallel coil groups.

[0035] The high-voltage side of the transformer includes three parallel coils: coil T4-B, coil T4-C, and coil group T4-E. The same-name terminals of the three parallel coils are connected to a step-up / step-down bridge rectifier circuit via two parallel resonant capacitors. The opposite-name terminals of the three parallel coils are directly connected to the step-up / step-down bridge rectifier circuit. Specifically, the step-up / step-down bridge rectifier circuit includes transistors Q8, Q12, Q17, and Q18. The source of transistor Q8 is connected to the drain of transistor Q12, the drain of transistor Q8 is connected to the drain of transistor Q17, the source of transistor Q17 is connected to the drain of transistor Q18, and the source of transistor Q12 is connected to the source of transistor Q18. The node connecting transistors Q8 and Q12 is connected to the end of the two parallel resonant capacitors furthest from the transformer, and this node is also connected to the step-up / step-down drive module. The node connecting transistors Q17 and Q18 is connected to the opposite-named terminals of the three parallel coils on the high-voltage side of the transformer, and this node is also connected to the buck-boost drive module. Specifically, the gate of transistor Q8 is connected to a voltage divider node formed by two series resistors (R27 and R15). The end of resistor R27 furthest from the voltage divider node is connected to the buck-boost drive module, and the end of resistor R15 furthest from the voltage divider node is connected to the source of transistor Q8. A diode D35 is connected in parallel across resistor R27. Similarly, the gate of transistor Q12 is connected to a voltage divider node formed by two series resistors (R29 and R28). The end of resistor R29 furthest from the voltage divider node is connected to the buck-boost drive module, and the end of resistor R28 furthest from the voltage divider node is connected to the source of transistor Q12. A diode D34 is connected in parallel across resistor R29. The gate of transistor Q17 is connected to a voltage divider node formed by two series resistors (R31 and R30). The end of resistor R31 furthest from the voltage divider node is connected to the buck-boost drive module, and the end of resistor R30 furthest from the voltage divider node is connected to the source of transistor Q17. A diode D36 is connected in parallel across resistor R31. The gate of transistor Q18 is connected to a voltage divider node formed by two series resistors (R39 and R33). The end of resistor R39 furthest from the voltage divider node is connected to the buck-boost drive module, and the end of resistor R33 furthest from the voltage divider node is connected to the source of transistor Q18. A diode D37 is connected in parallel across resistor R39. The drain of transistor Q8 is connected to the drain of transistor Q17 and then to the positive terminal of the bus capacitor. The source of transistor Q12 is connected to the source of transistor Q18 and then to the negative terminal of the bus capacitor.

[0036] like Figure 2As shown, the buck-boost driver module includes a first buck-boost driver chip and a second buck-boost driver chip. Both the first and second buck-boost driver chips are 8-pin chips. The first control signal pin of the first driver chip is connected to the control signal PWM-LLC4A through resistor R130, and the second control signal pin is connected to the control signal PWM-LLC4B through resistor R131. The first output pin of the first driver chip is connected to resistor R29, and the second and fourth output pins are connected to the node where transistors Q8 and Q12 are connected. The third output pin is connected to resistor R27. The first control signal pin of the second driver chip is connected to the control signal PWM-LLC5A through resistor R150, and the second control signal pin is connected to the control signal PWM-LLC5B through resistor R151. The first output pin of the second driver chip is connected to resistor R39, and the second and fourth output pins are connected to the node where transistors Q17 and Q18 are connected. The third output pin is connected to resistor R31.

[0037] The battery boost inverter process is as follows: The battery voltage input is 12.8V. The positive terminal of the battery is connected to the low-voltage side center tap of the push-pull transformer through four 40A fuses. Transistors Q9, Q10, Q13, and Q14 are two sets of NMOS transistors, driven by complementary transistors with a dead time of 180°. The high-voltage side of the transformer outputs a high-frequency square wave with amplitudes of ±400V. This wave passes through resonant capacitors C5 and C6, and is then synchronously rectified by full-bridge transistors Q8, Q12, Q17, and Q18. It is then filtered into 400V high-voltage DC at bus capacitor C48. Node COMA shares the same drive group as transistors Q12 and Q17, and node COMB shares the same drive group as transistors Q8 and Q18. The control method uses a fixed-frequency open-loop control. The LLC resonant circuit utilizes the leakage inductance of the push-pull transformer and the resonant capacitor to achieve a soft-switching effect.

[0038] Once the mains power sampling is normal, the DC / DC buck-boost module will be activated to boost the bus. During the boost process, the pulse width of the COMA and COMB nodes will gradually increase from 0, keeping the bus capacitor voltage at a relatively low slope to rise to over 300V. The boost time is usually around 2 seconds. After the boost is completed, the DC / DC buck-boost module will stop working, and the bidirectional input / output rectifier module will start charging.

[0039] The bidirectional input / output rectifier module includes an input / output bridge rectifier circuit, which comprises transistors Q3, Q4, Q5, and Q7. The drain of transistor Q3 is connected to the drain of transistor Q4, the source of transistor Q3 is connected to the drain of transistor Q5, the source of transistor Q4 is connected to the drain of transistor Q7, and the source of transistor Q7 is connected to the source of transistor Q5. The drains of transistors Q3 and Q4 are connected to the positive terminal of the bus capacitor, and the sources of transistors Q5 and Q7 are connected to the negative terminal of the bus capacitor. The gate of transistor Q3 is connected to a voltage divider node formed by two series resistors (R120 and R119). The end of resistor R120 furthest from the voltage divider node is connected to the bidirectional input / output rectifier drive module, and the end of resistor R119 furthest from the voltage divider node is connected to the source of transistor Q3. A diode D38 is connected in parallel across resistor R120. The gate of transistor Q4 is connected to a voltage divider node formed by two series resistors (R135 and R133). The end of resistor R135 furthest from the voltage divider node is connected to the bidirectional input / output rectifier drive module, and the end of resistor R133 furthest from the voltage divider node is connected to the source of transistor Q4. A diode D41 is connected in parallel across resistor R135. The gate of transistor Q5 is connected to a voltage divider node formed by two series resistors (R132 and R121). The end of resistor R132 furthest from the voltage divider node is connected to the bidirectional input / output rectifier drive module, and the end of resistor R121 furthest from the voltage divider node is connected to the source of transistor Q5. A diode D39 is connected in parallel across resistor R132. The gate of transistor Q7 is connected to the voltage divider node of two series resistors (resistors R137 and R136). The end of resistor R137 away from the voltage divider node is connected to the bidirectional input / output rectifier drive module, and the end of resistor R136 away from the voltage divider node is connected to the source of transistor Q7. A diode D40 is connected in parallel with resistor R137.

[0040] like Figure 3As shown, the bidirectional input / output rectifier driver module includes a first bidirectional input / output rectifier driver chip and a second bidirectional input / output rectifier driver chip. Both the first and second bidirectional input / output rectifier driver chips are 8-pin chips. The first control signal pin of the first bidirectional input / output rectifier driver chip is connected to the control signal PWM-INV1A through resistor R152, the second control signal pin of the first bidirectional input / output rectifier driver chip is connected to the control signal PWM-INV1B through resistor R153, the first output pin of the first bidirectional input / output rectifier driver chip is connected to resistor R132, the second output pin is connected to the fourth output pin and then connected to the node connected to transistors Q3 and Q5, and the third output pin is connected to resistor R120. The first control signal pin of the second bidirectional input / output rectifier driver chip is connected to the control signal PWM-INV2A through resistor R154. The second control signal pin of the second bidirectional input / output rectifier driver chip is connected to the control signal PWM-INV2B through resistor R155. The first output pin of the second bidirectional input / output rectifier driver chip is connected to resistor R137. The second output pin is connected to the fourth output pin and then connected to the node where transistors Q4 and Q7 are connected. The third output pin is connected to resistor R135.

[0041] The node connecting transistors Q4 and Q7 is connected to chip U4 via inductor L5. Chip U4 has a pin INV-L. Pin INV-L is connected to the AC input module, specifically as follows: Figure 4 As shown, the AC power input module includes a relay and an AC power input control circuit. The relay's two input terminals are connected to the INPUT-L and INPUT-N terminals of the AC power supply, respectively. The relay's two output terminals are INV-L and INV-N. INV-L is connected to pin INV-L of chip U4, and INV-N is connected to the node where transistors Q3 and Q5 are connected. The AC power input control circuit includes transistors Q19 and Q20. The collector of transistor Q19 is connected to the relay's control terminal, the emitter of transistor Q19 is grounded, and the base of transistor Q19 is connected to the microcontroller through resistor R42. The base of transistor Q20 is connected to the collector of transistor Q19 through resistor R44, and the collector of transistor Q20 is connected to the relay through capacitor C41.

[0042] The mains power is connected to the full-bridge inverter side through INV-L and INV-N. Chip U4 uses Hall effect sensors to collect the PFC current. Transistors Q3 and Q4 are used as diodes and are not driven during the entire charging process. During the positive half-cycle of the mains power, transistor Q7 is turned on, and transistor Q5 is not driven. The inductor energy storage path is: terminal INV-L - inductor L5 - transistor Q7 - negative terminal of bus capacitor (BUS-) - body diode of transistor Q5 - terminal INV-N. The rectified charging path is: terminal INV-L - inductor L5 - body diode of transistor Q4 - negative terminal of bus capacitor (BUS-) - body diode of transistor Q5 - terminal INV-N. During the negative half-cycle, transistor Q5 is working, and transistor Q7 is not driven. The inductor energy storage path is: terminal INV-N-transistor Q5-bus capacitor negative terminal (BUS-)-transistor Q7 body diode-inductor L5-terminal INV-L. The rectified charging path is: terminal INV-N-transistor Q3 body diode-bus capacitor negative terminal (BUS-)-transistor Q7 body diode-inductor L5-terminal INV-L.

[0043] like Figure 5 As shown, the mains voltage detection module includes a first operational amplifier, a second operational amplifier, and a third operational amplifier. The non-inverting input of the first operational amplifier is connected to terminal INPUT-L via three resistors in series (resistors R49, R40, and R56), and the inverting input of the first operational amplifier is connected to terminal INPUT-N via three resistors in series (resistors R50, R53, and R59). The non-inverting input of the second operational amplifier is connected to the output of the first operational amplifier via resistor R85. The inverting input of the second operational amplifier is also connected to its output. The output of the second operational amplifier is connected to the node INPUT-VOUT via resistor R89. The node INPUT-VOUT is connected to the microcontroller. The non-inverting input of the third operational amplifier is connected to a voltage divider node formed by two series resistors (resistors R92 and R90). One end of resistor R92 is connected to the third operational amplifier, and the other end is grounded. One end of resistor R90 is connected to the non-inverting input of the operational amplifier, and the other end is connected to the output of the third operational amplifier. The inverting input of the third operational amplifier is connected to the output of the first operational amplifier via resistor R93.

[0044] like Figure 6As shown, the BUS voltage detection module includes a BUS voltage detection operational amplifier. The non-inverting input of the BUS voltage detection operational amplifier is connected to node BUS+V. Node BUS+V is connected to node BUS+ through four resistors in series (resistors R112, R113, R114, and R115). The inverting input of the BUS voltage detection operational amplifier is connected to node BUS-V. Node BUS-V is connected to node BUS- through four resistors in series (resistors R108, R109, R110, and R111). Node BUS+ is connected to the positive terminal of the bus capacitor, and node BUS- is connected to the negative terminal of the bus capacitor.

[0045] The working principle of this invention is as follows: Mains power is connected to the circuit through terminals INPUT-L and INPUT-N. After being attenuated and boosted to a reference voltage of 1.65V by the differential sampling first operational amplifier U12, the voltage is fed into the microcontroller's DPS AD port for voltage calculation. The 50Hz square wave signal output from terminal INPUT-ZERO is fed into the microcontroller's DSP ECAP port for frequency calculation. When both the mains voltage and frequency are normal and the BUS voltage (bus capacitor voltage) is above 300V, the mains input relay K1 quickly engages through the voltage multiplier circuit. The mains neutral and live wires are connected to the inverter terminals INV-N and INV- / L to begin reverse PFC charging. If the bus voltage is not pre-activated before the relay engages, the mains power will charge the BUS capacitor through the uncontrolled rectification of the inverter's full-bridge body diodes, instantly breaking down the full-bridge IGBT body diodes and causing a mains short circuit.

[0046] It should be noted that the microcontroller in this embodiment is a TMS320F28035_LQFP80, as shown in the figure.

[0047] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A circuit for bidirectional inverter mains fast charging using an LLC circuit to gradually raise the bus capacitor voltage, characterized in that, It includes bus capacitors, DC / DC step-up / step-down modules, bidirectional input / output rectifier modules, step-up / step-down drive modules, bidirectional input / output rectifier drive modules, mains input modules, mains voltage detection modules, and BUS voltage detection modules; The DC / DC step-up / step-down module, bus capacitor, and bidirectional input / output rectifier module are electrically connected in sequence. The buck-boost drive module is electrically connected to the DC / DC buck-boost module; The bidirectional input / output rectifier drive module is electrically connected to the bidirectional input / output rectifier module; The mains power input module is electrically connected to the bidirectional input / output rectifier module; The mains voltage detection module is electrically connected to the mains input module; The BUS voltage detection module is electrically connected to the bus capacitor.

2. The circuit for bidirectional inverter mains fast charging via LLC to gradually raise the bus capacitor voltage as described in claim 1, characterized in that: The DC / DC buck-boost module includes a battery connection terminal, a fuse, a transformer, an NMOS complementary circuit, a resonant capacitor, and a buck-boost bridge rectifier circuit. The battery connection terminal is electrically connected to the fuse, the fuse is electrically connected to the low-voltage side of the transformer, the NMOS complementary circuit is electrically connected to the low-voltage side of the transformer, the high-voltage side of the transformer is electrically connected to the step-up / step-down bridge rectifier circuit through the resonant capacitor, and the step-up / step-down bridge rectifier circuit is electrically connected to the bus capacitor.

3. The circuit for bidirectional inverter mains fast charging via LLC to gradually raise the bus capacitor voltage as described in claim 1, characterized in that: The bidirectional input / output rectifier module includes an input / output bridge rectifier circuit, which is electrically connected to the bus capacitor.

4. The circuit for bidirectional inverter mains fast charging via LLC to gradually raise the bus capacitor voltage as described in claim 2, characterized in that: The buck-boost driver module includes a first buck-boost driver chip and a second buck-boost driver chip, which are electrically connected to the buck-boost bridge rectifier circuit.

5. The circuit for bidirectional inverter mains fast charging via LLC to gradually raise the bus capacitor voltage as described in claim 1, characterized in that: The bidirectional input / output rectifier driver module includes a first bidirectional input / output rectifier driver chip and a second bidirectional input / output rectifier driver chip, which are electrically connected to the input / output bridge rectifier circuit, respectively.

6. The circuit for bidirectional inverter mains fast charging via LLC to gradually raise the bus capacitor voltage according to claim 1, characterized in that: The mains input module includes a relay and a mains input control circuit. The relay is connected to the L terminal and N terminal of the mains power supply, respectively. The mains input control circuit is electrically connected to the relay and is connected to a microcontroller.

7. The circuit for bidirectional inverter mains fast charging via LLC to gradually raise the bus capacitor voltage as described in claim 6, characterized in that: The mains voltage detection module includes a first operational amplifier, a second operational amplifier, and a third operational amplifier; The non-inverting input of the first operational amplifier is electrically connected to the L terminal of the mains power supply, and the inverting input of the first operational amplifier is electrically connected to the N terminal of the mains power supply. The non-inverting input of the second operational amplifier is electrically connected to the output terminal of the first operational amplifier, and the inverting input of the second operational amplifier is electrically connected to the output terminal of the second operational amplifier. The output terminal of the second operational amplifier is connected to a microcontroller. The inverting input of the third operational amplifier is electrically connected to the output terminal of the first operational amplifier, and the non-inverting input of the third operational amplifier is grounded through a resistor. The output terminal of the third operational amplifier is connected to a microcontroller.

8. The circuit for bidirectional inverter mains fast charging via LLC to gradually raise the bus capacitor voltage according to claim 1, characterized in that: The BUS voltage detection module includes a BUS voltage detection operational amplifier. The non-inverting terminal of the BUS voltage detection operational amplifier is electrically connected to the positive terminal of the bus capacitor, and the inverting terminal of the BUS voltage monitoring operational amplifier is electrically connected to the negative terminal of the bus capacitor.

Images