Single lithium battery DC-DC boost and inversion drive circuit

Abstract

The utility model discloses a single lithium battery DC-DC boost and inversion drive circuit, which comprises a Boost unit, an inversion unit and a control unit, the Boost unit comprises a boost module and an auxiliary power supply module, the input end of the boost module is connected with a lithium battery, and the output end of the boost module outputs boosted direct current through the auxiliary power supply module; the inversion unit comprises a push-pull boosting module, a rectification module and an inversion module, the input end of the push-pull boosting module is connected with the lithium battery, the output end of the push-pull boosting module is connected with the input end of the inversion module through the rectification module, and the output end of the inversion module is used for outputting alternating current; the inversion module is connected with the control unit, and the inversion module is also connected with the auxiliary power supply module. According to the utility model, 3.2 V single batteries can be fully utilized, and the environmental pollution caused by waste batteries is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of lithium batteries, and particularly relates to a DC-DC boost and inverter drive circuit for a single lithium battery. Background Art

[0002] With the retirement of a large number of electric vehicle batteries, the cascade utilization of these batteries is a major problem currently faced. However, the retired batteries have a large discreteness and are not easy to be re-capacitance paired. While using a single large-capacity battery independently for energy storage can solve the above problems. In the prior art, there are mainly two ways to apply a single battery for energy storage: (1) Boost the battery voltage from 3.2Vdc to 310Vdc to supply power to a rectifying load. For example, connect to a charger to supply power to digital devices or drones; (2) Boost the battery voltage of 3.2Vdc and then invert it into alternating current to supply power to conventional electrical appliances, such as fans, computers, etc.

[0003] When boosting the voltage of the battery, a conventional push-pull boost circuit is usually used. When using this circuit, the following technical difficulties are faced:

[0004] (1) Auxiliary power supply problem: There is no Flyback auxiliary power supply control chip on the market that supports 3.2V; and when the rated input voltage is 3.2V, the voltage is low and the current is too large. Especially, there are problems with the design of a multi-channel isolated output auxiliary power supply. Only when the input voltage of the auxiliary power supply > 12V, there is a mature flyback auxiliary power supply solution; the necessary 12V voltage for driving the MOS cannot be solved;

[0005] (2) Push-pull transformer problem: The voltage is too low. When the output is 300W, the output current of the battery monomer exceeds 100A, and the current is too large. The ratio of the secondary side to the primary side of the transformer is 100:1, which makes it difficult to implement a conventional transformer;

[0006] (3) The drive of the modified sine wave inverter bridge on the market uses triodes. The upper half bridge uses high-voltage triodes, and the switching logics of the upper and lower half bridges are complementary, but the dead zone is not adjustable; when there is a non-linear load, there is a situation where the upper and lower MOS tubes are directly connected, and it is easy to burn out the MOS. Content of the Utility Model

[0007] In view of the above problems, the utility model provides a DC-DC boost and inverter drive circuit for a single lithium battery. To solve the above technical problems, the technical solutions adopted by the utility model are as follows:

[0008] A single lithium battery DC-DC boost and inverter drive circuit includes a Boost boost unit, an inverter unit, and a control unit. The Boost boost unit includes a boost module and an auxiliary power module. The input end of the boost module is connected to the lithium battery, and the output end of the boost module outputs the boosted direct current through the auxiliary power module. The inverter unit includes a push-pull boost module, a rectification module, and an inverter module. The input end of the push-pull boost module is connected to the lithium battery, and the output end of the push-pull boost module is connected to the input end of the inverter module through the rectification module. The output end of the inverter module is used to output alternating current. The inverter module is connected to the control unit and is also connected to the auxiliary power module.

[0009] The boost module includes a boost converter U3. The first pin of the boost converter U3 is connected to the second pin of the boost converter U3, one end of an inductor L1, one end of a resistor R140, and the positive pole of a diode D10. The other end of the resistor R140 is connected to one end of a capacitor C90. The third pin of the boost converter U3 is connected to one end of a capacitor C86. The fourth pin of the boost converter U3 is connected to one end of a capacitor C85 and one end of a resistor R41. The fifth pin of the boost converter U3 is connected to one end of a resistor R138 and one end of a resistor R40. The sixth pin of the boost converter U3 is connected to one end of a capacitor C89 and one end of a resistor R42. The other end of the resistor R42 is connected to one end of a capacitor C88. The seventh pin of the boost converter U3 is connected to one end of a resistor R139. The eighth pin of the boost converter U3 is connected to one end of a capacitor C87 and one end of a resistor R36. The other end of the resistor R36 is connected to the negative pole of the diode D10, the other end of the resistor R40, one end of a capacitor C52, one end of a capacitor C59, and the input end of the auxiliary power module. The other end of the inductor L1 is connected to the other end of the resistor R41, one end of a capacitor C60, and the positive pole of the lithium battery. The other ends of the capacitor C60, the capacitor C52, the capacitor C59, the capacitor C90, the capacitor C86, the capacitor C85, the 0th pin of the boost converter U3, the other end of the resistor R138, the other end of the capacitor C89, the other end of the capacitor C88, the other end of the resistor R139, and the other end of the capacitor C87 are all grounded.

[0010] The push-pull boost module includes a field-effect transistor Q21 and a field-effect transistor Q22. The drain of the field-effect transistor Q21 is connected to the 3rd pin of the transformer T1. The source of the field-effect transistor Q21 is connected to the source of the field-effect transistor Q22, one end of the capacitor C1, and the negative electrode of the lithium battery, and the source of the field-effect transistor Q21 is grounded. The other end of the capacitor C1 is connected to the positive electrode of the lithium battery and the 2nd pin of the transformer T1. The drain of the field-effect transistor Q22 is connected to the 1st pin of the transformer T1. The 4th pin of the transformer T1 is connected to one end of the capacitor C2. The 5th pin of the transformer T1 is floating. The 6th pin of the transformer T1 and the other end of the capacitor C2 are both connected to the input end of the rectification module.

[0011] The inverter module is connected to the control unit through the drive module, and the drive module is also connected to the auxiliary power supply module.

[0012] The inverter module includes a field-effect transistor Q3, a field-effect transistor Q4, a field-effect transistor Q7, and a field-effect transistor Q8. The drains of the field-effect transistors Q3 and Q4 are both connected to the output end of the rectification module. The source of the field-effect transistor Q3 is connected to one end of the resistor R9, one end of the capacitor CE1 of the drive module, and the drain of the field-effect transistor Q7. The gate of the field-effect transistor Q3 is connected to the other end of the resistor R9, the 1st pin and the 4th pin of the first dual general-purpose transistor Q1 of the drive module. The gate of the field-effect transistor Q7 is connected to one end of the resistor R15, the 1st pin and the 4th pin of the fourth dual general-purpose transistor Q6 of the drive module. The source of the field-effect transistor Q7 is connected to the other end of the resistor R15, the source of the field-effect transistor Q8, one end of the resistor R19, and one end of the resistor R16. The other end of the resistor R19 is grounded. The gate of the field-effect transistor Q8 is connected to the other end of the resistor R16, the 1st pin and the 4th pin of the third dual general-purpose transistor Q5 of the drive module. The drain of the field-effect transistor Q8 is connected to one end of the resistor R10, one end of the capacitor CE2 of the drive module, and the source of the field-effect transistor Q4. The gate of the field-effect transistor Q4 is connected to the other end of the resistor R10, the 1st pin and the 4th pin of the second dual general-purpose transistor Q2 of the drive module. And the sources of the field-effect transistors Q3 and Q4 are both used to output alternating current.

[0013] The drive module includes a first dual general-purpose transistor Q1, a second dual general-purpose transistor Q2, a third dual general-purpose transistor Q5, and a fourth dual general-purpose transistor Q6. The first pin of the first dual general-purpose transistor Q1 is connected to the fourth pin of the first dual general-purpose transistor Q1 and the gate of the field-effect transistor Q3 of the inverter module. The second pin of the first dual general-purpose transistor Q1 is connected to the fifth pin of the first dual general-purpose transistor Q1, one end of the resistor R7, and the third pin of the first optocoupler OP1. The third pin of the first dual general-purpose transistor Q1 is connected to one end of the capacitor CE1, the source of the field-effect transistor Q3 of the inverter module, and the other end of the resistor R7. The fourth pin of the first optocoupler OP1 is connected to one end of the resistor R5, the other end of the capacitor CE1, and the negative electrode of the diode D1. The other end of the resistor R5 is connected to the sixth pin of the first dual general-purpose transistor Q1. The positive electrode of the diode D1 is connected to one end of the resistor R1. The first pin of the first optocoupler OP1 is connected to one end of the resistor R3. The first pin of the second dual general-purpose transistor Q2 is connected to the fourth pin of the second dual general-purpose transistor Q2 and the gate of the field-effect transistor Q4 of the inverter module. The second pin of the second dual general-purpose transistor Q2 is connected to the fifth pin of the second dual general-purpose transistor Q2, one end of the resistor R8, and the third pin of the second optocoupler OP2. The third pin of the second dual general-purpose transistor Q2 is connected to one end of the capacitor CE2, the source of the field-effect transistor Q4 of the inverter module, and the other end of the resistor R8. The fourth pin of the second optocoupler OP2 is connected to one end of the resistor R6, the other end of the capacitor CE2, and the negative electrode of the diode D2. The other end of the resistor R6 is connected to the sixth pin of the second dual general-purpose transistor Q2. The positive electrode of the diode D2 is connected to one end of the resistor R2. The first pin of the second optocoupler OP2 is connected to one end of the resistor R4. The first pin of the third dual general-purpose transistor Q5 is connected to the fourth pin of the third dual general-purpose transistor Q5 and the gate of the field-effect transistor Q8 of the inverter module. The second pin of the third dual general-purpose transistor Q5 is connected to the fifth pin of the third dual general-purpose transistor Q5, one end of the resistor R17, and the third pin of the fourth optocoupler OP4. The sixth pin of the third dual general-purpose transistor Q5 is connected to one end of the resistor R13. The other end of the resistor R13 is connected to the fourth pin of the fourth optocoupler OP4. The first pin of the fourth optocoupler OP4 is connected to one end of the resistor R11. The first pin of the fourth dual general-purpose transistor Q6 is connected to the fourth pin of the fourth dual general-purpose transistor Q6 and the gate of the field-effect transistor Q7 of the inverter module. The second pin of the fourth dual general-purpose transistor Q6 is connected to the fifth pin of the fourth dual general-purpose transistor Q6, one end of the resistor R18, and the third pin of the third optocoupler OP3. The sixth pin of the fourth dual general-purpose transistor Q6 is connected to one end of the resistor R14. The other end of the resistor R14 is connected to the fourth pin of the third optocoupler OP3. The first pin of the third optocoupler OP3 is connected to one end of the resistor R12;The other end of resistor R3, the other end of resistor R4, the second pin of the third optocoupler OP3, and the second pin of the fourth optocoupler OP4 are all connected to the control unit. The other end of resistor R1, the other end of resistor R2, the fourth pin of the fourth optocoupler OP4, and the fourth pin of the third optocoupler OP3 are all connected to the auxiliary power supply module; the other ends of resistor R11 and resistor R12 are used to receive a DC voltage signal with the same amplitude as the PWM signal output by the control unit; the second pin of the first optocoupler OP1, the second pin of the second optocoupler OP2, the third pin of the third dual general transistor Q5, the third pin of the fourth dual general transistor Q6, the other end of resistor R17, and the other end of resistor R18 are all grounded.

[0014] Advantages of the present utility model:

[0015] 1. Through the present invention, 3.2V single-cell batteries can be fully utilized, reducing environmental pollution caused by waste batteries;

[0016] 2. Changing the drive of the modified-wave inverter bridge to optocoupler drive + totem IC has good consistency. By sending logic-complementary PWM signals to two pairs of half-bridges through the MCU, the defects of analog controllers (such as TL494) can be solved, and a modified-wave inverter with adjustable dead-time PWM waves can be realized, ensuring that the MOS transistors on the half-bridges of the inverter will never conduct directly at any time, avoiding device burnout, with higher reliability, improving the compatibility of the inverter with various loads, and being more user-friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model 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 following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a structural schematic diagram of the present utility model;

[0019] Figure 2 It is a circuit structural schematic diagram of the boost module;

[0020] Figure 3 It is a circuit structural schematic diagram of the auxiliary power supply module;

[0021] Figure 4 It is a circuit structural schematic diagram of the inverter module;

[0022] Figure 5 It is one of the circuit partial structural schematic diagrams of the drive module;

[0023] Figure 6 The second schematic diagram of the circuit part structure of the driving module;

[0024] Figure 7 The third schematic diagram of the circuit part structure of the driving module;

[0025] Figure 8 The fourth schematic diagram of the circuit part structure of the driving module. Specific implementation manner

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] A single lithium battery DC-DC boost and inverter drive circuit, as Figure 1 shown, includes a Boost boost unit, an inverter unit, and a control unit. The control unit can control the inverter unit. The Boost boost unit includes a boost module and an auxiliary power supply module. Through the boost module, the voltage output by the battery can be boosted to 12V. The input end of the boost module is connected to the lithium battery, the output end of the boost module is connected to the auxiliary power supply module, and a stable 15V DC voltage is output through the auxiliary power supply module to supply power for the subsequent inverter bridge drive; the inverter unit includes a push-pull boost module, a rectification module, and an inverter module. The input end of the push-pull boost module is connected to the output end of the lithium battery, the output end of the push-pull boost module is connected to the input end of the rectification module, the output end of the rectification module is connected to the input end of the inverter module, the output end of the inverter module is used to output 220V alternating current, and the inverter module is connected to the control unit. The control unit samples the voltage of the inverter module and realizes the stability of the inverter voltage target value through PWM duty cycle adjustment.

[0028] As Figure 2As shown, the boost module includes a boost converter U3. The first pin of the boost converter U3 is connected to the second pin of the boost converter U3, one end of the inductor L1, one end of the resistor R140, and the positive pole of the diode D10. The other end of the resistor R140 is connected to one end of the capacitor C90. The third pin of the boost converter U3 is connected to one end of the capacitor C86. The fourth pin of the boost converter U3 is connected to one end of the capacitor C85 and one end of the resistor R41. The fifth pin of the boost converter U3 is connected to one end of the resistor R138 and one end of the resistor R40. The sixth pin of the boost converter U3 is connected to one end of the capacitor C89 and one end of the resistor R42. The other end of the resistor R42 is connected to one end of the capacitor C88. The seventh pin of the boost converter U3 is connected to one end of the resistor R139. The eighth pin of the boost converter U3 is connected to one end of the capacitor C87 and one end of the resistor R36. The other end of the resistor R36 is connected to the negative pole of the diode D10, the other end of the resistor R40, one end of the capacitor C52, one end of the capacitor C59, and the input end of the auxiliary power supply module; The other end of the inductor L1 is connected to the other end of the resistor R41, one end of the capacitor C60, and the positive pole of the lithium battery; The other ends of the capacitor C60, the capacitor C52, the capacitor C59, the capacitor C90, the capacitor C86, the capacitor C85, the 0th pin of the boost converter U3, the other end of the resistor R138, the other end of the capacitor C89, the other end of the capacitor C88, the other end of the resistor R139, and the other end of the capacitor C87 are all grounded.

[0029] The boost module is a typical BOOST circuit, and a controller with an internal MOS of model FP6296XR is used as the boost converter U3. By continuously turning off and on, energy is stored in the inductor L1, superimposed on the input 3.2V, and finally boosted to a stable 12V DC. This circuit is the key to the operation of a 3.2V single-cell large-capacity lithium battery system, which can boost the battery voltage to 12V with a power of about 18 - 20W.

[0030] The auxiliary power supply module includes a Flyback input and control module, a transformer T2, and several DC output modules. The input end of the Flyback input and control module is used to receive the 12V DC voltage output by the boost module. The output end of the Flyback input and control module is connected to one side of the transformer T2, and the other side of the transformer T2 is respectively connected to several DC output modules to output the same or different DC voltages to supply power to the corresponding rectifying loads. In this embodiment, there are two types of DC output modules. One is the DC output module with an output of 12V, and the other is the DC output module with an output of 15V. In this application, through two-stage conversion, first, it is boosted to 12V by the boost module, and then the 12V is used as the flyback power input to design the auxiliary power supply required by the system through the transformer.

[0031] As Figure 3 shown, the DC output module with an output of 15V includes a diode D27. The positive electrode of the diode D27 is connected to the 9th pin of the transformer T2D, and the negative electrode of the diode D27 is connected to one end of a capacitor C28 and one end of a resistor R28. The other end of the capacitor C28, the other end of the resistor R28, and the 8th pin of the transformer T2D are all grounded, and one end of the resistor R28 serves as the output end of the 15V DC voltage to supply power to the load. The diode D27 is a rectifier diode, and the capacitor C28 is a filter capacitor, which is used to filter out the clutter signals in the rectified voltage to make the output voltage more stable. The DC output module with an output of 12V includes a diode D25. The positive electrode of the diode D25 is connected to the 2nd pin of the transformer T2E, and the negative electrode of the diode D25 is connected to one end of a capacitor C32, one end of a capacitor C31, and one end of a resistor R35. The other end of the capacitor C32, the other end of the capacitor C31, the other end of the resistor R35, and the 1st pin of the transformer T2E are all grounded, and one end of the resistor R35 serves as the output end of the 12V DC voltage.

[0032] As Figure 3As shown in the figure, the Flyback input and control module includes a power management chip U2. The first pin of the power management chip U2 is connected to one end of a resistor R26, one end of a resistor R34, and one end of a capacitor C35. The second pin of the power management chip U2 is connected to the other end of the capacitor C35, the positive electrode of a diode D9, one end of a capacitor C33, one end of a resistor R29, one end of a capacitor C34, and one end of a resistor R37. The third pin of the power management chip U2 is connected to the negative electrode of a diode D3, one end of a resistor R32, and the negative electrode of the diode D9. The fourth pin of the power management chip U2 is connected to the other end of the resistor R29, the other end of the capacitor C33, and the positive electrode of a zener diode ZD1. The fifth pin of the power management chip U2 is connected to the other end of the capacitor C34, the negative electrode of the zener diode ZD1, the output end of a boost module, one end of a capacitor C26, one end of a capacitor C25, the other end of the resistor R26, one end of a resistor R27, and the third pin of a transformer T2C. The sixth pin of the power management chip U2 is connected to one end of a resistor R31 and the other end of the resistor R37. The other end of the resistor R31 is connected to the output end of a DC output module with an output of 12V. The other end of the resistor R34 is connected to one end of a resistor R33, one end of a resistor R39, one end of a resistor R38, and the source electrode of a field effect transistor Q13. The other end of the resistor R33 is connected to the other end of the resistor R32, one end of a resistor R30, and the gate electrode of the field effect transistor Q13. The other end of the resistor R30 is connected to the positive electrode of the diode D3. The drain electrode of the field effect transistor Q13 is connected to the positive electrode of a diode D26, one end of a capacitor C27, and the fourth pin of the transformer T2C. The other end of the capacitor C27 is connected to one end of a resistor R25. The other end of the resistor R25 is connected to the negative electrode of the diode D26, one end of a capacitor C30, and the other end of the resistor R27. The other ends of the capacitor C26, the capacitor C25, the resistor R39, the resistor R38, and the capacitor C30 are all grounded. In this embodiment, the model of the power management chip U2 is SY7711, and SY7711 is a low-voltage start Flyback controller. The transformer T2C, the transformer T2E, and the transformer T2D together form the transformer T2 to output the required stable voltage through the transformer.

[0033] After the battery voltage of 3.2V is boosted to 12V by the boost module, it serves as the Flyback input voltage. The Flyback controller generates a PWM signal to chop the 12V input. After energy storage through the transformer T2E, the energy is rectified and filtered through the first and second pins of the main winding of the transformer to output a 12V voltage. This 12V voltage is simultaneously fed back to the input end of the Flyback controller. Another part of the energy passes through the eighth and ninth pins of another winding, and after rectification and filtering, a set of 15V DC voltage is output to supply power to the inverter bridge drive.

[0034] The push-pull boost module includes a field effect transistor Q21 and a field effect transistor Q22. The drain of the field effect transistor Q21 is connected to the 3rd pin of the transformer T1. The source of the field effect transistor Q21 is connected to the source of the field effect transistor Q22, one end of the capacitor C1, and the negative electrode of the lithium battery, and the source of the field effect transistor Q21 is grounded; the other end of the capacitor C1 is connected to the positive electrode of the lithium battery and the 2nd pin of the transformer T1. The drain of the field effect transistor Q22 is connected to the 1st pin of the transformer T1. The 4th pin of the transformer T1 is connected to one end of the capacitor C2. The 5th pin of the transformer T1 is floating. The 6th pin of the transformer T1 and the other end of the capacitor C2 are both connected to the input end of the rectification module. The gates of the field effect transistor Q21 and the field effect transistor Q22 are not floating and can be connected to corresponding drive signals. This is the prior art and will not be elaborated in this embodiment. The field effect transistor Q21 and the field effect transistor Q22 are both push-pull boost chopper power transistors. T1 is a boost transformer. The capacitor C1 and the capacitor C2 are both resonant capacitors, which form a quasi-resonant rectification with the leakage inductance of the transformer.

[0035] The control unit can adopt an MCU. The power supply of the MCU can be obtained by adjusting the output of the auxiliary power supply module, and the MCU is connected to the inverter module through the drive module. The MCU is the center of the entire control unit. By sampling the BUS bus, it adjusts the duty cycle of the PWM for controlling the inverter module to maintain the output voltage stable near the set value. The function of the drive module is to amplify the 3.3V level signal sent by the MCU into a voltage signal capable of driving the MOS of the inverter bridge of the inverter module. In this embodiment, the model of the MCU is GD32F330F8P6TR. The push-pull boost module chops the 3.2V battery voltage signal of the lithium battery through the MOS tube, and couples it to the secondary with a high turn ratio of the transformer. The voltage is amplified to N times, and then rectified by the rectification module in a bridge rectification to become the DC bus voltage (i.e., the BUS voltage); the control unit issues a corresponding PWM signal, which is amplified by the drive module and controls the operation of the 4 MOS tubes of the inverter bridge to output a stable AC voltage and frequency for the electrical appliance to use. The rectification module is a bridge rectification, and the rectified output is a DC bus voltage of 280Vdc.

[0036] As Figure 4As shown, the inverter module includes field effect transistors Q3, Q4, Q7, and Q8. The drains of field effect transistors Q3 and Q4 are both connected to the output terminal of the rectifier module. The source of field effect transistor Q3 is connected to one end of resistor R9, one end of capacitor CE1 of the drive module, and the drain of field effect transistor Q7. The gate of field effect transistor Q3 is connected to the other end of resistor R9, the first pin of the first dual general-purpose transistor Q1 of the drive module, and the fourth pin of the first dual general-purpose transistor Q1. The gate of field effect transistor Q7 is connected to one end of resistor R15, the first pin of the fourth dual general-purpose transistor Q6 of the drive module, and the fourth pin of the fourth dual general-purpose transistor Q6. The source of field effect transistor Q7 is connected to the other end of resistor R15, the source of field effect transistor Q8, one end of resistor R19, and one end of resistor R16. The other end of resistor R19 is grounded; the gate of field effect transistor Q8 is connected to the other end of resistor R16, the first pin of the third dual general-purpose transistor Q5 of the drive module, and the fourth pin of the third dual general-purpose transistor Q5. The drain of field effect transistor Q8 is connected to one end of resistor R10, one end of capacitor CE2 of the drive module, and the source of field effect transistor Q4. The gate of field effect transistor Q4 is connected to the other end of resistor R10, the first pin of the second dual general-purpose transistor Q2 of the drive module, and the fourth pin of the second dual general-purpose transistor Q2. And the sources of field effect transistors Q3 and Q4 are respectively used as two ports for outputting alternating current. Field effect transistors Q3, Q4, Q7, and Q8 are inverter bridge MOS transistors; resistors R9, R10, R15, and R16 are all pull-down resistors at the feet of the gates and sources of the MOS transistors to prevent electrostatic damage to the MOS transistors.

[0037] As Figures 5 - 8As shown, the drive module includes a first dual general-purpose transistor Q1, a second dual general-purpose transistor Q2, a third dual general-purpose transistor Q5, and a fourth dual general-purpose transistor Q6. In this embodiment, the models of the first dual general-purpose transistor Q1, the second dual general-purpose transistor Q2, the third dual general-purpose transistor Q5, and the fourth dual general-purpose transistor Q6 are all LBC817. The first pin of the first dual general-purpose transistor Q1 is connected to the fourth pin of the first dual general-purpose transistor Q1 and the gate of the field-effect transistor Q3 of the inverter module. The second pin of the first dual general-purpose transistor Q1 is connected to the fifth pin of the first dual general-purpose transistor Q1, one end of the resistor R7, and the third pin of the first optocoupler OP1. The third pin of the first dual general-purpose transistor Q1 is connected to one end of the capacitor CE1, the source of the field-effect transistor Q3 of the inverter module, and the other end of the resistor R7. The fourth pin of the first optocoupler OP1 is connected to one end of the resistor R5, the other end of the capacitor CE1, and the negative electrode of the diode D1. The other end of the resistor R5 is connected to the sixth pin of the first dual general-purpose transistor Q1. The positive electrode of the diode D1 is connected to one end of the resistor R1. The first pin of the first optocoupler OP1 is connected to one end of the resistor R3. The first pin of the second dual general-purpose transistor Q2 is connected to the fourth pin of the second dual general-purpose transistor Q2 and the gate of the field-effect transistor Q4 of the inverter module. The second pin of the second dual general-purpose transistor Q2 is connected to the fifth pin of the second dual general-purpose transistor Q2, one end of the resistor R8, and the third pin of the second optocoupler OP2. The third pin of the second dual general-purpose transistor Q2 is connected to one end of the capacitor CE2, the source of the field-effect transistor Q4 of the inverter module, and the other end of the resistor R8. The fourth pin of the second optocoupler OP2 is connected to one end of the resistor R6, the other end of the capacitor CE2, and the negative electrode of the diode D2. The other end of the resistor R6 is connected to the sixth pin of the second dual general-purpose transistor Q2. The positive electrode of the diode D2 is connected to one end of the resistor R2. The first pin of the second optocoupler OP2 is connected to one end of the resistor R4. The first pin of the third dual general-purpose transistor Q5 is connected to the fourth pin of the third dual general-purpose transistor Q5 and the gate of the field-effect transistor Q8 of the inverter module. The second pin of the third dual general-purpose transistor Q5 is connected to the fifth pin of the third dual general-purpose transistor Q5, one end of the resistor R17, and the third pin of the fourth optocoupler OP4. The sixth pin of the third dual general-purpose transistor Q5 is connected to one end of the resistor R13. The other end of the resistor R13 is connected to the fourth pin of the fourth optocoupler OP4. The first pin of the fourth optocoupler OP4 is connected to one end of the resistor R11;The first pin of the fourth dual general-purpose transistor Q6 is connected to the fourth pin of the fourth dual general-purpose transistor Q6 and the gate of the field-effect transistor Q7 of the inverter module. The second pin of the fourth dual general-purpose transistor Q6 is connected to the fifth pin of the fourth dual general-purpose transistor Q6, one end of the resistor R18, and the third pin of the third optocoupler OP3. The sixth pin of the fourth dual general-purpose transistor Q6 is connected to one end of the resistor R14. The other end of the resistor R14 is connected to the fourth pin of the third optocoupler OP3. The first pin of the third optocoupler OP3 is connected to one end of the resistor R12. The other end of the resistor R3, the other end of the resistor R4, the second pin of the third optocoupler OP3, and the second pin of the fourth optocoupler OP4 are all connected to the MCU. PWM-A and PWM-B are two PWM signals sent by the main control MCU. The other end of the resistor R1, the other end of the resistor R2, the fourth pin of the fourth optocoupler OP4, and the fourth pin of the third optocoupler OP3 are all connected to the output end of the DC output module with an output of 15V. The other end of the resistor R11 and the other end of the resistor R12 are used to receive a 3.3V DC voltage signal, which can be obtained by stepping down the output of any DC output module. The second pin of the first optocoupler OP1, the second pin of the second optocoupler OP2, the third pin of the third dual general-purpose transistor Q5, the third pin of the fourth dual general-purpose transistor Q6, the other end of the resistor R17, and the other end of the resistor R18 are all grounded. In this embodiment, the models of the first optocoupler OP1, the second optocoupler OP2, the third optocoupler OP3, and the fourth optocoupler OP4 are all HK1019, which play a role in driving signal isolation to better drive the MOS transistor.

[0038] The resistors R5, R6, R13, and R14 are all drive current-limiting resistors, which play a role in protecting the dual general-purpose transistors. The dual general-purpose transistors Q1, Q2, Q5, and Q6 are all totem amplification ICs to improve the driving ability. CE1 / CE2 are bootstrap circuit energy storage capacitors to drive the MOS. The drive module amplifies the 3.3V PWM signal sent by the MCU into a signal that can directly drive the field-effect power transistor of the inverter bridge. The inverter bridge is composed of 4 field-effect power MOS transistors, which are controlled by the drive signal output by the drive module to chop the high-voltage DC of the DC bus output by the rectification module into an AC square wave output, and the pulse width is the same as the pulse width of the PWM signal sent by the MCU.

[0039] The MCU emits PWM-A and PWM-B with a frequency of 50Hz and complementary logic. Taking the half-bridge composed of field-effect transistor Q3 and field-effect transistor Q7 as an example, specifically, when PWM-A is 0, there is current flowing between the first pin and the second pin of the third optocoupler OP3, and the third pin and the fourth pin of the third optocoupler OP3 are conducting. The fourth dual general-purpose transistor Q6 outputs a high level to the gate of the field-effect transistor Q7, and the drain and source of the field-effect transistor Q7 are conducting; since PWM-A is 0, there is no current flowing between the first pin and the second pin of the first optocoupler OP1, and the third pin and the fourth pin of the first optocoupler OP1 are not conducting. The first dual general-purpose transistor Q1 outputs a low level to the gate of the field-effect transistor Q3, and the field-effect transistor Q3 is turned off, which is equivalent to the source of the field-effect transistor Q3 being grounded, that is Figure 4 the node M1 in is grounded. Therefore, the 15V DC voltage output by the DC output module charges the capacitor CE1 through the resistor R1 and the diode D1. At this time, Figure 4 the node N1 in is equivalent to being connected to GND.

[0040] When PWM-A is 1, there is no current flowing between the first pin and the second pin of the third optocoupler OP3, and the third pin and the fourth pin of the third optocoupler OP3 are turned off. At this time, the fourth dual general-purpose transistor Q6 outputs a low level to the gate of the field-effect transistor Q7, and the drain and source of the field-effect transistor Q7 are turned off; since PWM-A is 1, there is current flowing between the first pin and the second pin of the first optocoupler OP1, and the third pin and the fourth pin of the first optocoupler OP1 are conducting. At the same time, the voltage difference between the 15V DC voltage output by the DC output module and the capacitor CE1 drives the first dual general-purpose transistor Q1 through the resistor R5. The first dual general-purpose transistor Q1 outputs a high level to the gate of the field-effect transistor Q3, and the field-effect transistor Q3 is conducting. At this time, Figure 4 the node N1 in is directly connected to the bus voltage.

[0041] Similarly, the field-effect transistors Q4 and Q8 also form a half-bridge, and the control logic of its signals is opposite to that of the half-bridge composed of the field-effect transistors Q3 and Q7. Through alternating switching, finally, Figure 4 a stable AC voltage with both voltage and frequency is output between the node L1 and the node N1 in.

[0042] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A single lithium battery DC-DC boost and inverter drive circuit, characterized in that: It includes a Boost unit, an inverter unit and a control unit. The Boost unit includes a boost module and an auxiliary power module. The input end of the boost module is connected to a lithium battery, and the output end of the boost module outputs boosted DC power through the auxiliary power module. The inverter unit includes a push-pull boost module, a rectifier module and an inverter module. The input end of the push-pull boost module is connected to a lithium battery, the output end of the push-pull boost module is connected to the input end of the inverter module through the rectifier module, and the output end of the inverter module is used to output AC power. The inverter module is connected to the control unit, and the inverter module is also connected to the auxiliary power module.

2. The single lithium battery DC-DC boost and inverter drive circuit according to claim 1, characterized in that: The boost module includes a boost converter U3, wherein the first pin of the boost converter U3 is connected to the second pin of the boost converter U3, one end of the inductor L1, one end of the resistor R140, and the positive electrode of the diode D10, the other end of the resistor R140 is connected to one end of the capacitor C90, the third pin of the boost converter U3 is connected to one end of the capacitor C86, the fourth pin of the boost converter U3 is connected to one end of the capacitor C85 and one end of the resistor R41, the fifth pin of the boost converter U3 is connected to one end of the resistor R138 and one end of the resistor R40, the sixth pin of the boost converter U3 is connected to one end of the capacitor C89 and one end of the resistor R42, the other end of the resistor R42 is connected to one end of the capacitor C88, the seventh pin of the boost converter U3 is connected to one end of the resistor R139 The 8th pin of the boost converter U3 is connected to one end of the capacitor C87 and one end of the resistor R36, and the other end of the resistor R36 is connected to the negative electrode of the diode D10, the other end of the resistor R40, one end of the capacitor C52, one end of the capacitor C59, and the input end of the auxiliary power module; the other end of the inductor L1 is connected to the other end of the resistor R41, one end of the capacitor C60, and the positive electrode of the lithium battery; the other end of the capacitor C60, the other end of the capacitor C52, the other end of the capacitor C59, the other end of the capacitor C90, the other end of the capacitor C86, the other end of the capacitor C85, the 0th pin of the boost converter U3, the other end of the resistor R138, the other end of the capacitor C89, the other end of the capacitor C88, the other end of the resistor R139, and the other end of the capacitor C87 are all grounded.

3. The single lithium battery DC-DC boost and inverter drive circuit according to claim 1, characterized in that: The push-pull boost module includes a field effect tube Q21 and a field effect tube Q22, the drain of the field effect tube Q21 is connected to the third pin of the transformer T1, the source of the field effect tube Q21 is connected to the source of the field effect tube Q22, one end of the capacitor C1, and the negative electrode of the lithium battery, and the source of the field effect tube Q21 is grounded; the other end of the capacitor C1 is connected to the positive electrode of the lithium battery and the second pin of the transformer T1, the drain of the field effect tube Q22 is connected to the first pin of the transformer T1, the fourth pin of the transformer T1 is connected to one end of the capacitor C2, the fifth pin of the transformer T1 is suspended, and the sixth pin of the transformer T1 and the other end of the capacitor C2 are both connected to the input end of the rectifier module.

4. The single lithium battery DC-DC boost and inverter drive circuit according to claim 1, characterized in that: The inverter module is connected to the control unit via the drive module, and the drive module is also connected to the auxiliary power supply module.

5. The single lithium battery DC-DC boost and inverter drive circuit according to claim 4, characterized in that: The inverter module includes a field effect tube Q3, a field effect tube Q4, a field effect tube Q7 and a field effect tube Q8. The drains of the field effect tubes Q3 and Q4 are connected to the output end of the rectifier module. The source of the field effect tube Q3 is connected to one end of the resistor R9, one end of the capacitor CE1 of the driving module, and the drain of the field effect tube Q7. The gate of the field effect tube Q3 is connected to the other end of the resistor R9, the first pin of the first dual universal transistor Q1 of the driving module, and the fourth pin of the first dual universal transistor Q1. The gate of the field effect tube Q7 is connected to one end of the resistor R15, the first pin of the fourth dual universal transistor Q6 of the driving module, and the fourth pin of the fourth dual universal transistor Q6. The source of the field effect tube Q7 is connected to the resistor R15. The other end of the field effect tube Q8, the source of the field effect tube Q8, one end of the resistor R19, and one end of the resistor R16 are connected, and the other end of the resistor R19 is grounded; the gate of the field effect tube Q8 is connected to the other end of the resistor R16, the first pin of the third dual general-purpose transistor Q5 of the driving module, and the fourth pin of the third dual general-purpose transistor Q5, the drain of the field effect tube Q8 is connected to one end of the resistor R10, one end of the capacitor CE2 of the driving module, and the source of the field effect tube Q4, the gate of the field effect tube Q4 is connected to the other end of the resistor R10, the first pin of the second dual general-purpose transistor Q2 of the driving module, and the fourth pin of the second dual general-purpose transistor Q2, and the source of the field effect tube Q3 and the source of the field effect tube Q4 are both used to output alternating current.

6. The single lithium battery DC-DC boost and inverter drive circuit according to claim 4, characterized in that: The driving module includes a first dual universal transistor Q1, a second dual universal transistor Q2, a third dual universal transistor Q5 and a fourth dual universal transistor Q6, the first pin of the first dual universal transistor Q1 is connected to the fourth pin of the first dual universal transistor Q1 and the gate of the field effect transistor Q3 of the inverter module, the second pin of the first dual universal transistor Q1 is connected to the fifth pin of the first dual universal transistor Q1, one end of the resistor R7, and the third pin of the first optical coupler OP1, the third pin of the first dual universal transistor Q1 is connected to one end of the capacitor CE1, the source of the field effect transistor Q3 of the inverter module, and the other end of the resistor R7, the fourth pin of the first optical coupler OP1 is connected to one end of the resistor R5, the other end of the capacitor CE1, The cathode of the diode D1 is connected, the other end of the resistor R5 is connected to the 6th pin of the first dual universal transistor Q1, the anode of the diode D1 is connected to one end of the resistor R1, and the 1st pin of the first optical coupler OP1 is connected to one end of the resistor R3; the 1st pin of the second dual universal transistor Q2 is connected to the 4th pin of the second dual universal transistor Q2 and the gate of the field effect tube Q4 of the inverter module, the 2nd pin of the second dual universal transistor Q2 is connected to the 5th pin of the second dual universal transistor Q2, one end of the resistor R8, and the 3rd pin of the second optical coupler OP2, the 3rd pin of the second dual universal transistor Q2 is connected to one end of the capacitor CE2, the source of the field effect tube Q4 of the inverter module, and the other end of the resistor R8, and the second optical coupler OP1 is connected to the cathode of the diode D1, the other end of the resistor R5 is connected to the 6th pin of the first dual universal transistor Q1, the anode of the diode D1 is connected to one end of the resistor R1, and the 1st pin of the first optical coupler OP1 is connected to one end of the resistor R3; the 1st pin of the second dual universal transistor Q2 is connected to the 4th pin of the second dual universal transistor Q2 and the gate of the field effect tube Q4 of the inverter module, the 2nd pin of the second dual universal transistor Q2 is connected to the 5th pin of the second dual universal transistor Q2, one end of the resistor R8, and the 3rd pin of the second optical coupler OP2 The 4th pin of the coupler OP2 is connected to one end of the resistor R6, the other end of the capacitor CE2, and the negative electrode of the diode D2, the other end of the resistor R6 is connected to the 6th pin of the second dual universal transistor Q2, the positive electrode of the diode D2 is connected to one end of the resistor R2, and the 1st pin of the second optical coupler OP2 is connected to one end of the resistor R4; the 1st pin of the third dual universal transistor Q5 is connected to the 4th pin of the third dual universal transistor Q5 and the gate of the field effect transistor Q8 of the inverter module, the 2nd pin of the third dual universal transistor Q5 is connected to the 5th pin of the third dual universal transistor Q5, one end of the resistor R17, and the 3rd pin of the fourth optical coupler OP4, the 6th pin of the third dual universal transistor Q5 is connected to one end of the resistor R13, and the 4th pin of the third dual universal transistor Q5 is connected to the gate of the field effect transistor Q8 of the inverter module, and the 2nd pin of the third dual universal transistor Q5 is connected to the 5th pin of the third dual universal transistor Q5, one end of the resistor R17, and the 3rd pin of the fourth optical coupler OP4. The other end of the resistor R13 is connected to the 4th pin of the fourth optical coupler OP4, and the 1st pin of the fourth optical coupler OP4 is connected to one end of the resistor R11; the 1st pin of the fourth dual general-purpose transistor Q6 is connected to the 4th pin of the fourth dual general-purpose transistor Q6 and the gate of the field effect transistor Q7 of the inverter module, the 2nd pin of the fourth dual general-purpose transistor Q6 is connected to the 5th pin of the fourth dual general-purpose transistor Q6, one end of the resistor R18, and the 3rd pin of the third optical coupler OP3, the 6th pin of the fourth dual general-purpose transistor Q6 is connected to one end of the resistor R14, the other end of the resistor R14 is connected to the 4th pin of the third optical coupler OP3, and the 1st pin of the third optical coupler OP3 is connected to one end of the resistor R12;The other end of the resistor R3, the other end of the resistor R4, the second pin of the third optical coupler OP3, and the second pin of the fourth optical coupler OP4 are all connected to the control unit, and the other end of the resistor R1, the other end of the resistor R2, the fourth pin of the fourth optical coupler OP4, and the fourth pin of the third optical coupler OP3 are all connected to the auxiliary power module; the other end of the resistor R11 and the other end of the resistor R12 are used to receive a DC voltage signal with the same amplitude as the PWM signal output by the control unit; the second pin of the first optical coupler OP1, the second pin of the second optical coupler OP2, the third pin of the third dual general transistor Q5, the third pin of the fourth dual general transistor Q6, the other end of the resistor R17, and the other end of the resistor R18 are all grounded. ;

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