Vehicle-mounted inverter

Abstract

The vehicle-mounted inverter comprises a power supply module, a mainboard circuit, a PWM control circuit and an SPWM drive circuit which are connected in sequence, the mainboard circuit comprises a direct-current boosting module and a voltage conversion module, the power supply module is connected with the direct-current boosting module and the PWM control circuit, the PWM control circuit is further connected with the direct-current boosting module, and the SPWM drive circuit is connected with the voltage conversion module. The SPWM driving circuit is respectively connected with the PWM control circuit and the voltage conversion module, the PWM control circuit comprises a first chip and a second chip, and the second chip is used for collecting each path of signal in the mainboard circuit and judging whether each path of collected signal is normal or not; and the first chip is used for driving the direct-current boosting module to start working if each path of signal acquired by the second chip is normal. When the vehicle-mounted inverter breaks down, the current fault of the inverter can be fed back, and the reliability and the safety of the vehicle-mounted inverter are improved.

Description

Technical Field

[0001] The invention belongs to the field of automobile low-voltage power supply systems, and in particular relates to an on-vehicle inverter. Background Art

[0002] At present, there are more and more scenarios where cars use household appliances during daily driving. Under the low-voltage power supply system of the whole vehicle, for traditional fuel vehicles, the low-voltage power supply system is responsible for supplying power to all electrical loads of the whole vehicle. For hybrid, extended-range and pure electric models, the low-voltage power supply system is responsible for providing power to all low-voltage electrical loads except high-voltage motors and high-voltage air-conditioning systems. However, customers are not only satisfied with the electrical appliances provided on the whole vehicle. Although most cars provide 220V AC sockets, which solves the problem of using most household appliances during driving, customers' demand for household appliances on vehicles increases in different scenarios, and the power of different household appliances varies greatly. That is, with the development of electrification and intelligence of automobiles, the problem of the whole vehicle providing equipment to power more household appliances in daily vehicle scenarios is becoming increasingly apparent, and it has become a technical problem that needs to be solved more and more urgently. Summary of the invention

[0003] In view of the above problems, the object of the present invention is to provide a vehicle-mounted inverter, comprising a power supply module, a main board circuit, a PWM control circuit, and an SPWM drive circuit connected in sequence, wherein the main board circuit comprises a DC boost module and a voltage conversion module, the power supply module is respectively connected to the DC boost module and the PWM control circuit, the PWM control circuit is also connected to the DC boost module, and the SPWM drive circuit is respectively connected to the PWM control circuit and the voltage conversion module, wherein:

[0004] A power supply module, used for providing power input;

[0005] The PWM control circuit includes a first chip and a second chip, wherein the second chip is used to collect various signals in the mainboard circuit and determine whether the collected various signals are normal; the first chip is used to drive the DC boost module to start working if the various signals collected by the second chip are normal;

[0006] The mainboard circuit is used to collect its own output voltage, output current and MOS tube temperature signal, and send them to the SPWM drive circuit;

[0007] The SPWM driving circuit is used to determine whether the mainboard circuit is short-circuited, overloaded and / or the machine temperature is too high based on the output voltage, output current and / or MOS tube temperature signal. If so, the driving voltage conversion module stops working, and the AC fault abnormality feedback signal is fed back to the PWM control circuit, so that the second chip controls the first chip to stop working, and finally the DC boost module stops working.

[0008] Furthermore, the power supply module is connected to the PWM control circuit through the ACC switch, and the power supply module includes a battery, a transistor Q6, and a MOS tube Q4. When the ACC signal is turned on, the transistor Q6 is turned on, and the MOS tube Q4 is turned on. The positive electrode of the battery can supply 14.9V power to the vehicle inverter through the MOS tube Q4.

[0009] The battery is a DC 12V low-voltage battery of a low-voltage power supply system, wherein the DC 12V low-voltage battery of the low-voltage power supply system includes a flooded lead-acid battery, an enhanced flooded lead-acid battery, a glass fiber valve-regulated battery, a lithium iron phosphate battery, a ternary lithium battery, a lithium manganese oxide battery, and a sodium ion battery.

[0010] Furthermore, the mainboard circuit also includes a voltage feedback circuit, which is connected to the rectifier and filter circuit, and the voltage feedback circuit is also connected to the first chip of the PWM control circuit through a closed-loop voltage stabilization circuit; wherein,

[0011] The voltage feedback circuit is used to collect the voltage signal after the DC boost module is boosted and determine whether it is normal. If there is overvoltage or undervoltage, it means that the battery voltage is too high or too low. The closed-loop voltage stabilization circuit outputs the PU-1 signal and feeds it back to the first chip of the PWM control circuit.

[0012] Furthermore, the PWM control circuit further includes MOS tubes Q1, Q2, Q3, Q5, and Q7, wherein the MOS tube Q1 is connected to the closed-loop voltage stabilization circuit and the first chip respectively, the gates of the MOS tubes Q5 and Q7 are connected to the first chip, and the gates of the MOS tubes Q2 and Q3 are connected to the first chip, forming two groups of totem pole circuits, wherein:

[0013] The PWM control circuit is also used to amplify the driving signal through two groups of totem pole circuits of MOS tubes Q2, Q3, Q5, and Q7 to drive the DC boost module in the mainboard circuit to work; and,

[0014] When the PU-1 signal is received, the MOS tube Q1 is driven to stop conducting, and the first chip stops working, so that the DC boost module stops working.

[0015] Furthermore, the SPWM drive circuit includes a third chip, a first signal drive amplifier chip, a second signal drive amplifier chip and an amplifier circuit, the third chip is connected to the first signal drive amplifier chip and the second signal drive amplifier chip respectively, and the first signal drive amplifier chip and the second signal drive amplifier chip are also connected to the amplifier circuit respectively, wherein,

[0016] The third chip generates a first drive signal and a second drive signal. The first drive signal is amplified by the first signal driving amplifier chip and the amplifier circuit respectively, and the second drive signal is amplified by the second signal driving amplifier chip and the amplifier circuit respectively. The amplified first drive signal and the second drive signal respectively drive the voltage conversion module in the mainboard circuit to work.

[0017] Furthermore, the mainboard circuit also includes an auxiliary power circuit, an AC fault indication circuit, a leakage protection circuit, a fault indicator light circuit and a current feedback circuit, wherein:

[0018] The auxiliary power circuit is connected to the transformer T1 and the third chip respectively, and is used to output auxiliary power of 15V and 5V to the third chip respectively;

[0019] The AC fault indication circuit is connected to the second chip and the third chip respectively, and the AC fault indication circuit includes a second optical coupler for triggering an AC fault abnormality feedback signal and sending it to the second chip when receiving an enable signal from the third chip in the SPWM drive circuit;

[0020] The fault indicator light circuit is connected to the second chip in the PWM drive circuit, and is used to control the fault indicator light to light up when the second chip receives the AC fault abnormality feedback signal and the leakage protection signal;

[0021] A leakage protection circuit is used to cut off the power supply to protect the mainboard circuit when receiving a leakage protection signal;

[0022] The current feedback circuit is connected to the negative terminal of the output end of the voltage conversion module and the third chip respectively, and is used to collect the output current of the mainboard circuit and send it to the third chip.

[0023] Furthermore, the mainboard circuit includes a first EMC absorption circuit and a second EMC absorption circuit, wherein:

[0024] The input end of the first EMC absorption circuit is connected to the power supply module through a fuse, and the output end is connected to the DC boost module and the ACC switch respectively, so as to filter the input power supply and remove noise;

[0025] The input end of the second EMC absorption circuit is connected to the voltage conversion module, and the output end is connected to the socket, and is used to filter out the electromagnetic radiation of the output voltage of the voltage conversion module.

[0026] Furthermore, it also includes an input connector and input wire N1, a waterproof ring for the outlet hole and a lower shell N2, an insulating sheet N3, a waterproof ring N4, a PCB board N5, screws for locking the PCB board N6, an upper shell N7, screws for locking the upper and lower shells N8, an output wire and an output connector N9; wherein,

[0027] During assembly, install the insulating sheet N3 on the bottom of the lower shell in the waterproof ring of the outlet hole and the lower shell N2, assemble the waterproof ring N4 on the four assembly edges of the lower shell in the waterproof ring of the outlet hole and the lower shell N2, complete the welding of the components on the PCB board N5, weld the input wires and output wires in the input connector and input wire N1 and the output wires in the output connector N9 to the PCB board N5, and then assemble the welded PCB board N5 on the lower shell in the waterproof ring of the outlet hole and the lower shell N2, and fasten the PCB board N5 with the PCB board locking screw N6, and then assemble the upper shell N7. When assembling the upper shell N7, the input wires and output wires in the input connector and input wire N1 and the output wires in the output connector N9 need to be placed on the outlet hole of the lower shell in the waterproof ring of the outlet hole and the lower shell N2, and then the upper shell N7 and the lower shell in the waterproof ring of the outlet hole and the lower shell N2 are fastened with the upper and lower shell locking screws N8.

[0028] Furthermore, it also includes a power socket, which includes a protective cover C1, a connecting rod C2, a panel and an upper shell C3, an LED lamp C4, a PCB board C5, a lower shell C6, and connecting screws C7 between the upper shell and the lower shell; wherein,

[0029] During assembly, the protective cover C1 is assembled on the upper shell through the connecting rod C2, and the protective cover C1 is rotated and opened and closed using the connecting rod C2 as an axis. The terminals are welded on the PCB board C5, and the LED lamp C4 is fixed on the PCB board C5. Then the PCB board C5 is assembled into the panel and the upper shell C3, and then the lower shell C6 is assembled. The upper shell C3 and the lower shell C6 are buckled together and fastened by the connecting screws C7 of the upper shell and the lower shell.

[0030] Furthermore, LED lamp C4 is connected to the fault indicator light circuit of the main board circuit to display the working status of the vehicle inverter, and when there are abnormal signals in the various signals collected by the second chip, different indication states are displayed based on different fault states.

[0031] The vehicle-mounted inverter of the present invention can meet the use of household appliances in daily scenarios on the whole vehicle, and when the inverter fails, it can feedback the current fault of the inverter, thereby improving the applicability of the inverter, as well as the reliability and reliability of the inverter, and further improving the user experience.

[0032] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or be understood by implementing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 A schematic structural diagram of a vehicle-mounted inverter in an embodiment of the present invention is shown;

[0035] Figure 2 A schematic structural diagram of another vehicle-mounted inverter in an embodiment of the present invention is shown;

[0036] Figure 3 A circuit diagram of a power supply module in an embodiment of the present invention is shown;

[0037] Figure 4 A circuit diagram of a mainboard circuit in an embodiment of the present invention is shown;

[0038] Figure 4a A circuit diagram of the left side of the dotted line in a mainboard circuit in an embodiment of the present invention is shown;

[0039] Figure 4b A circuit diagram of the portion on the right side of the dotted line in a mainboard circuit in an embodiment of the present invention is shown;

[0040] Figure 5 A circuit diagram of a PWM control circuit in an embodiment of the present invention is shown;

[0041] Figure 6 A vehicle inverter fault control flow chart in an embodiment of the present invention is shown;

[0042] Figure 7 A circuit diagram of an SPWM drive circuit in an embodiment of the present invention is shown;

[0043] Figure 8 An exploded diagram of a vehicle-mounted inverter in an embodiment of the present invention is shown;

[0044] Fig. 9 An exploded view of a power socket supporting a vehicle-mounted inverter in an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] like Figure 1 As shown, an embodiment of the present invention introduces a vehicle-mounted inverter, the vehicle-mounted inverter includes a power supply module, a main board circuit, a PWM control circuit, and an SPWM drive circuit connected in sequence, the main board circuit includes a DC boost module and a voltage conversion module, the power supply module is respectively connected to the DC boost module and the PWM control circuit, the PWM control circuit is also connected to the DC boost module, the SPWM drive circuit is respectively connected to the PWM control circuit and the voltage conversion module, wherein the power supply module is used to provide power input; the PWM control circuit includes a first chip and a second chip, wherein the second chip is used to determine whether each channel of collected signals is normal, and to determine whether each channel of collected signals is normal. The first chip is used to drive the DC boost module to start working if the signals collected by the second chip are normal; the mainboard circuit is used to collect its own output voltage, output current and MOS tube temperature signal, and send them to the SPWM drive circuit; the SPWM drive circuit is used to determine whether the mainboard circuit has a short circuit, overload and / or high machine temperature based on the output voltage, output current and / or MOS tube temperature signal. If so, the drive voltage conversion module stops working, and the AC fault abnormality feedback signal is fed back to the PWM control circuit, so that the second chip controls the first chip to stop working, and finally stops the DC boost module. When the inverter in the embodiment of the present invention fails, the current fault of the inverter can be fed back, which improves the reliability and safety of the vehicle inverter.

[0047] Specifically, Figure 2 As shown, the power supply module is connected to the PWM control circuit via an ACC switch. Figure 3 As shown, the power supply module includes a battery, a transistor Q6, and a MOS tube Q4, wherein when the ACC signal is turned on, the transistor Q6 is turned on, and the MOS tube Q4 is turned on, and the positive electrode of the battery can provide 14.9V power to the vehicle inverter through the MOS tube Q4. The battery is a low-voltage power supply system DC 12V low-voltage battery, wherein the low-voltage power supply system DC 12V low-voltage battery can be one of the batteries such as a flooded lead-acid battery, an enhanced flooded lead-acid battery, a glass fiber valve-regulated battery, a lithium iron phosphate battery, a ternary lithium battery, a lithium manganate battery, and a sodium ion battery. However, it is not limited to this, and other batteries are also suitable for the present invention.

[0048] like Figure 2 , 4 As shown in Figures 4a and 4b, the circuit diagram of the mainboard circuit includes two major parts: a DC boost module and a voltage conversion module. The DC boost module is the DCDC (direct current to direct current) conversion part, and the voltage conversion module is the DCAC (direct current to alternating current) conversion part. Further, the DCDC (direct current to direct current) conversion part includes a PWM drive switch circuit, a transformer T1, and a rectifier filter circuit connected in sequence. Among them, the PWM drive switch circuit includes MOS tubes Q1 and Q5, and the rectifier filter circuit includes a rectifier bridge formed by diodes D1, D2, D4, and D5 and a capacitor C1. Under the control of the PWM drive circuit, the MOS tubes Q1 and Q5 boost the 12V DC input voltage of BT+ and BT- through the transformer T1, and then rectify through the diodes D1, D2, D4, and D5 and filter through the capacitor C1 to output a 380V DC voltage. The DCAC (direct current to alternating current) conversion part includes a T2 common mode inductor and an SPWM drive switch circuit. The SPWM drive switch circuit is connected to the SPWM drive circuit and the T2 common mode inductor respectively. The SPWM drive switch circuit includes MOS tubes Q2, Q3, Q6, and Q7 that constitute an H-bridge circuit, wherein MOS tubes Q2 and Q3 constitute the upper arm of the H-bridge, and MOS tubes Q6 and Q7 constitute the lower arm of the H-bridge. The DCAC conversion part is a 380V direct current voltage that is modulated and controlled by the third chip U1 in the SPWM drive circuit through the four MOS tubes Q2, Q3, Q6, and Q7, and the high-frequency noise signal in the output signal is filtered out through the common mode inductor T2, so as to convert the 380V direct current voltage into a 220V AC alternating current output.

[0049] In addition, the mainboard circuit will also collect the voltage, current and MOS tube temperature signals of the output 220V AC power, and transmit the signals to the third chip U1 in the SPWM drive circuit. If there is a short circuit, overload and / or the machine temperature is too high, the SPWM drive circuit will stop driving the four MOS tubes Q2, Q3, Q6, and Q7, so that the DCAC conversion part stops working, and the AC fault abnormality feedback signal is fed back to the PWM control circuit, so that the second chip U2 in the PWM control circuit controls the first chip U1 to stop working, and the DCDC conversion part stops working. Specifically, the AC voltage is the VFB (AC-VFB) signal, such as Figure 4 , 4bIn the figure, the circuit for collecting AC voltage includes R1, R2, R3, R55, and capacitor C2. The current is an IFB signal, and the circuit for collecting current is a current feedback circuit, including resistors R41 and R. The temperature signal of the MOS tube is a TFB (NTC) signal. The NTC (Negative Temperature Coefficient) thermistor is attached near the MOS tube (not shown in the figure). If the temperature of the MOS tube exceeds a certain threshold, the temperature of the machine is too high. When the VFB signal, IFB signal or TFB signal is abnormal, they are all fed back to the third chip U1. The third chip U1 outputs a PU-2 signal to control the action of the transistor Q4 on the mainboard circuit, so that the closed-loop voltage stabilization circuit on the mainboard circuit outputs a PU-1 signal, so that the front-stage drive PWM drive circuit stops working. Furthermore, the enable EN of pin 40 of the third chip U1 can also allow the AC fault feedback signal of the mainboard circuit to be fed back to the first chip. Furthermore, for a short circuit fault, the drive will be stopped directly through the SPWM drive circuit.

[0050] Figure 4 , 4a 4b, the mainboard circuit also includes an auxiliary source circuit, a closed-loop voltage stabilization circuit, an AC fault indication circuit, a leakage protection circuit, a fault indicator circuit and a current feedback circuit, wherein the auxiliary source circuit is connected to the transformer T1 and the third chip respectively, and the auxiliary source circuit includes a rectifier filter composed of diodes D8, D9 and RC, and the transformer T1 outputs a voltage, which is processed by a rectifier filter circuit composed of diodes D8, D9 and RC, and outputs 15V and 5V auxiliary power supplies to the third chip respectively, for powering the third chip. However, it is not limited to powering only the third chip U3, but also powers other circuits in the vehicle inverter.

[0051] The closed-loop voltage stabilization circuit includes an optical coupler PC1 connected to the voltage feedback circuit and the first chip U1 respectively. When the transistor Q4 in the voltage feedback circuit is activated, the optical coupler PC1 is triggered to output a PU-1 signal, so that the front-stage driving PWM driving circuit stops working.

[0052] The AC fault indication circuit is connected to the second chip U2 and the third chip U1 respectively. The AC fault indication circuit includes an optocoupler PC2. When receiving the EN signal enabling the third chip U1 in the SPWM drive circuit, the optocoupler PC2 triggers the AC fault abnormality feedback signal and sends it to the second chip U2.

[0053] The fault indicator light circuit is connected to the second chip U2 in the PWM drive circuit. PIN No. 2 of U2 is connected to the fault light signal, which is connected to the main board circuit through CON1 to control the LED light to light up.

[0054] The leakage protection circuit includes resistors R49, R50, R52, R53, R54, R57, R58, R60, R61, capacitors C31, C32, C33, diode D14, Zener diode U2, and transistor Q8, and is used to cut off the power supply to protect the mainboard circuit when receiving the leakage protection signal DATA.

[0055] The current feedback circuit is connected to the negative terminal of the 380V high voltage direct current (the negative terminal of the output terminal of the voltage conversion module) and the third chip U3 respectively, and is used to collect the output current of the mainboard circuit and send it to the third chip U3.

[0056] The mainboard circuit also includes a voltage feedback circuit. The DC boost module is connected to the voltage feedback circuit through a rectifier and filter circuit. The voltage feedback circuit is also connected to the first chip U1 of the PWM control circuit through a closed-loop voltage stabilization circuit. The voltage feedback circuit is used to collect the voltage signal after the DC boost module is boosted, and determine whether the voltage signal is normal. If there is overvoltage or undervoltage, it means that the battery voltage is too high or too low, that is, the voltage signal is not within the preset range. If it is higher than the preset range or lower than the preset range, it is overvoltage or undervoltage, respectively. The closed-loop voltage stabilization circuit is triggered to output the PU-1 signal to feedback to the first chip U1 of the PWM control circuit. After the PWM control circuit receives the PU-1 signal, the first chip U1 stops working, which stops the DCDC conversion part from working. Specifically, Figure 4b In the embodiment, the voltage feedback circuit includes capacitors C7, C14, C22, resistors R12, R13, R14, R15, R16, R17, R18, R19, R28, R31, transistor Q4 and zener diode U1.

[0057] The mainboard circuit also includes a first EMC absorption circuit and a second EMC absorption circuit, namely, Figure 2 The EMC absorption circuit in the DCDC conversion part and the EMC absorption circuit in the DCAC conversion part, wherein the input end of the first EMC absorption circuit is connected to the power supply module through a fuse, and the output end is connected to the DC boost module and the ACC switch respectively, wherein, Figure 4a In the embodiment, the first EMC absorption circuit includes a common mode inductor T3, a common mode inductor T4 and capacitors C15, C16, C41, C42, C43 and C44, which are used to filter the input power supply and remove noise. The input end of the second EMC absorption circuit is connected to the voltage conversion module, and the output end is connected to the socket, wherein: Figure 4b In the embodiment, the second EMC absorption circuit includes capacitors C11, C5, C8, C9, C12, C13, and C40, which are used to filter out electromagnetic radiation of the output voltage of the voltage conversion circuit.

[0058] like Figure 5As shown, the PWM control circuit includes a first chip U1, a second chip U2, MOS tubes Q1, Q2, Q3, Q5, and Q7. The MOS tube Q1 is connected to the closed-loop voltage stabilization circuit and the first chip U1 respectively. After the gates of the MOS tubes Q5 and Q7 are connected, they are connected to the pin 11 of the first chip U1. After the gates of the MOS tubes Q2 and Q3 are connected, they are connected to the pin 14 of the first chip U1, forming two groups of totem pole circuits, wherein the inverter starts to work, the first chip U1 and the second chip U2 of the PWM control circuit are powered on and reset, and the initialization program is run. The second chip U2 collects various signals through AD for judgment and processing. The various signals include leakage protection signal DATA, AC fault abnormality feedback signal and other signals. The AC fault abnormality feedback signal also includes circuit short circuit and overload in the vehicle inverter. Preferably, the second chip U2 includes multiple AD modules (analog to digital conversion acquisition modules). Figure 6 As shown, run the initialization program, first determine whether the inverter is faulty, if not, the mainboard circuit outputs 220VAC, if the machine fails, determine whether the machine has returned to normal, if not, the output remains closed, and the fault indicator light displays the fault, and returns to continue AD acquisition of various signals, if the machine returns to normal, it outputs 220VAC. The above fault control process will first detect at the start of the work, and then start the output if there is no fault. It will keep detecting during work, and the vehicle inverter will stop working if a fault occurs.

[0059] If the mainboard circuit outputs 220VAC normally, it will determine whether there is overload, battery voltage is too high, battery voltage is too low and / or machine temperature is too high. If any of these exists, the output will be turned off, the fault indicator light will be displayed, and the process will return to continue AD acquisition of various signals. If everything is normal, the normal indicator light will be displayed, and the process will return to continue AD acquisition of various signals.

[0060] Furthermore, if the second chip U2 determines that the vehicle inverter has no fault, the first chip U1 works, and the U1 chip generates a set of complementary square wave drive signals, and amplifies the drive capability through two sets of totem pole circuits Q2, Q3 and Q5, Q7, driving the two MOS tubes Q1 and Q5 on the main board circuit to conduct alternately, and the DCDC conversion part of the main board circuit of the vehicle inverter works, that is, the 12V DC input voltage of BT+ and BT- is boosted to 380VDC voltage through transformer T1. In addition, the auxiliary source circuit also starts to work, and then the SPWM drive circuit works, controlling the DCAC conversion part of the main board circuit to work and output 220V AC.

[0061] When the PWM control circuit receives the PU-1 signal, the driving control MOS tube Q1 stops conducting, the first chip U1 stops working, no driving signal is output, and finally the DCDC conversion part of the main board circuit stops working.

[0062] Through AD, various signals are collected, machine product signals are collected, and it is determined whether the product is in a fault state. If a fault occurs, the product will shut down the output to protect the electrical equipment and improve the safety and reliability of the vehicle inverter.

[0063] like Figure 7 As shown, the SPWM drive circuit includes a third chip U1, a first signal drive amplifier chip U3, a second signal drive amplifier chip U4 and an amplifier circuit. The third chip is an MCU. The SPWM drive circuit is Figure 2 The MCU control circuit in the SPWM drive circuit is connected to the first signal drive amplifier chip U3 and the second signal drive amplifier chip U4 respectively, and the first signal drive amplifier chip U3 and the second signal drive amplifier chip U4 are also connected to the amplifier circuit respectively, wherein the MCU generates two sets of H-bridge drive signals, namely the first drive signal and the second drive signal, the first drive signal is respectively amplified by the first signal drive amplifier chip U3 and the amplifier circuit to amplify the drive capability, and the second drive signal is respectively amplified by the second signal drive amplifier chip U4 to drive the amplifier chip and the amplifier circuit to amplify the drive capability, and the four MOS tubes Q2, Q3, Q6, and Q7 of the DCAC conversion part in the driving mainboard circuit are alternately turned on to convert the 380V DC voltage into a 220V AC voltage output, specifically, as Figure 4 As shown, the D pole (drain) of MOS tubes Q2 and Q7 is close to the 380V positive pole and is called the "upper bridge", and the D pole of MOS tubes Q3 and Q6 is close to the ground and is called the "lower bridge". Under unipolar modulation, the Q2 and Q6 sides are high-frequency arms (23KHz modulation wave, SPWM high-frequency sine square wave), and the Q3 and Q7 sides are low-frequency arms (50Hz square wave, PWM low-frequency square wave). The output after high and low frequency mixed modulation on both sides is similar to a sine wave (with high-frequency components), and then becomes a sine wave after modulation by the LC circuit. The direction of the AC current keeps changing. The full-bridge circuit composed of Q2, Q3, Q6, and Q7 converts DC into AC. When Q2 and Q7 are turned on, the 3rd side of the common-mode inductor T2 is the positive pole, and the 4th side of the common-mode inductor T2 is the negative pole. When Q3 and Q6 are turned on, the 3rd side of the common inductor T2 is the negative pole, and the 4th side of the common inductor T2 is the positive pole. There is alternation between the two sides to form alternating current, and 220V alternating current is output. The output 220V alternating current is processed by the second EMC absorption circuit and output to the socket for external use.

[0064] The amplifier circuit includes an amplifier U2A and an amplifier U2B. The amplifiers U2A and U2B amplify the SPWM signal and the PWM signal input to the U3 and U4 driving chips through SPWM-SD and PWM-SD.

[0065] like Figure 8As shown, the vehicle inverter also includes an input connector and an input line N1, a waterproof ring for an outlet hole and a lower shell N2, an insulating sheet N3, a waterproof ring N4, a PCB board N5, a screw N6 for locking the PCB board, an upper shell N7, a screw N8 for locking the upper and lower shells, an output line and an output connector N9; wherein, during assembly, the insulating sheet N3 is installed at the bottom of the lower shell in the waterproof ring for the outlet hole and the lower shell N2, the waterproof ring N4 is installed at the four assembly edges of the lower shell in the waterproof ring for the outlet hole and the lower shell N2, the circuit components on the PCB board N5 are welded, and the input connector and the input line N1 and the output line N2 are welded. The output wire in the output connector N9 is welded and connected to the PCB board N5, and then the welded PCB board N5 is assembled on the waterproof ring of the outlet hole and the lower shell in the lower shell N2, and the PCB board N5 is fastened with the locking screw N6, and then the upper shell N7 is assembled. When assembling the upper shell N7, the input wire and output wire in the input connector and input wire N1 and the output wire in the output connector N9 need to be placed on the outlet hole of the lower shell in the waterproof ring of the outlet hole and the lower shell in the lower shell N2, and then the upper shell N7 and the outlet hole waterproof ring and the lower shell in the lower shell N2 are fastened with the locking screws N8. Further, the circuit elements on the PCB board N5 are the elements of each circuit described above.

[0066] Further, if Fig. 9 As shown, the vehicle inverter also includes a power socket, which includes a protective cover C1, a connecting rod C2, a panel and an upper shell C3, an LED lamp C4, a PCB board C5, a lower shell C6, and connecting screws C7 between the upper shell and the lower shell; wherein, during assembly, the protective cover C1 is assembled on the upper shell through the connecting rod C2, the protective cover C1 is rotated and opened and closed using the connecting rod C2 as an axis, the terminal is welded on the PCB board C5, the LED lamp C4 is fixed on the PCB board C5, and then the PCB board C5 is assembled into the upper shell of the panel and the upper shell C3, and then the lower shell C6 is assembled, the upper shell C3 and the lower shell C6 are buckled together, and are fastened by the connecting screws C7 between the upper shell and the lower shell.

[0067] It draws power from the DC 12V low-voltage battery of the low-voltage system under the automotive electronic and electrical architecture, converts the DC 12V power supply into AC 220V50Hz mains power supply, and then outputs it through the vehicle-mounted inverter socket, matching the plugs of household appliances for customer convenience.

[0068] LED lamp C4 is connected to the fault indicator circuit of the main board circuit to display the working status of the vehicle inverter and to display different indication states based on different fault states when the vehicle inverter is in a fault state. For example, different fault signals and indicator states are shown in Table 1. Table 1 Relationship between fault states and indicator states

[0069]

[0070] When a fault occurs, the MCU controls the output to be turned off and controls the LED light to display the fault status. The fault status is displayed through the LED status, which improves the troubleshooting efficiency of the vehicle inverter and improves the application reliability of the vehicle inverter.

[0071] Furthermore, the vehicle inverter is protected according to the fault status. Specifically, the output voltage: please check whether the rated power of the electrical equipment is greater than 150W. If the power is greater than 150W, it cannot be used normally.

[0072] Short circuit protection: Please remove the electrical equipment, check whether the electrical equipment is damaged, and restart the inverter.

[0073] Overload protection: Please check whether the rated power of the electrical equipment is greater than 150W. If the power is greater than 150W, it cannot be used normally.

[0074] Over-temperature protection: The inverter is over-temperature. Please move it to a normal temperature environment and turn on the inverter after cooling down.

[0075] Overvoltage protection: Battery input is overvoltage, please check whether the input battery or generator is faulty.

[0076] Undervoltage protection: The battery input is undervoltage. Please turn on the ignition and engine to replenish the battery before use.

[0077] Leakage protection: The inverter outputs high voltage leakage. Please check whether the inverter or the output line is damaged and short-circuited with the vehicle body.

[0078] Inverter freezes: After powering on, check whether the inverter output has 220VAC voltage. If not, the inverter is damaged. Please check whether the inverter input and output terminals are well connected. If so, please replace the inverter and return it for further analysis.

[0079] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vehicle-mounted inverter, characterized in that: It includes a power supply module, a main board circuit, a PWM control circuit, and an SPWM drive circuit connected in sequence. The main board circuit includes a DC boost module and a voltage conversion module. The power supply module is connected to the DC boost module and the PWM control circuit respectively. The PWM control circuit is also connected to the DC boost module. The SPWM drive circuit is connected to the PWM control circuit and the voltage conversion module respectively. A power supply module, used for providing power input; The PWM control circuit includes a first chip and a second chip, wherein the second chip is used to collect various signals in the mainboard circuit and determine whether the collected various signals are normal; the first chip is used to drive the DC boost module to start working if the various signals collected by the second chip are normal; The mainboard circuit is used to collect its own output voltage, output current and MOS tube temperature signal, and send them to the SPWM drive circuit; The SPWM driving circuit is used to determine whether the mainboard circuit is short-circuited, overloaded and / or the machine temperature is too high based on the output voltage, output current and / or MOS tube temperature signal. If so, the driving voltage conversion module stops working, and the AC fault abnormality feedback signal is fed back to the PWM control circuit, so that the second chip controls the first chip to stop working, and finally the DC boost module stops working.

2. The vehicle-mounted inverter according to claim 1, characterized in that: The power supply module is connected to the PWM control circuit through the ACC switch, and the power supply module includes a battery, a transistor Q6, and a MOS tube Q4. When the ACC signal is turned on, the transistor Q6 is turned on, so that the MOS tube Q4 is turned on, and the positive electrode of the battery can supply 14.9V power to the vehicle inverter through the MOS tube Q4; The battery is a DC 12V low-voltage battery of a low-voltage power supply system, wherein the DC 12V low-voltage battery of the low-voltage power supply system includes one of a flooded lead-acid battery, an enhanced flooded lead-acid battery, a glass fiber valve-regulated battery, a lithium iron phosphate battery, a ternary lithium battery, a lithium manganese oxide battery, and a sodium ion battery.

3. The vehicle-mounted inverter according to claim 1 or 2, characterized in that: The mainboard circuit also includes a voltage feedback circuit, which is connected to the rectifier and filter circuit. The voltage feedback circuit is also connected to the first chip of the PWM control circuit through a closed-loop voltage stabilization circuit; wherein, The voltage feedback circuit is used to collect the voltage signal after the DC boost module is boosted and determine whether the voltage signal is normal. If there is overvoltage or undervoltage, it means that the battery voltage is too high or too low. The PU-1 signal is output through the closed-loop voltage stabilization circuit and fed back to the first chip of the PWM control circuit.

4. The vehicle-mounted inverter according to any one of claims 1 to 3, characterized in that: The PWM control circuit also includes MOS tubes Q1, Q2, Q3, Q5, and Q7. The MOS tube Q1 is connected to the closed-loop voltage stabilization circuit and the first chip respectively. The gates of the MOS tubes Q5 and Q7 are connected to the first chip, and the gates of the MOS tubes Q2 and Q3 are connected to the first chip, forming two groups of totem pole circuits, wherein: The PWM control circuit is also used to amplify the driving signal through two groups of totem pole circuits of MOS tubes Q2, Q3, Q5, and Q7 to drive the DC boost module in the mainboard circuit to work; and, When the PU-1 signal is received, the MOS tube Q1 is driven to stop conducting, and the first chip stops working, so that the DC boost module stops working.

5. The vehicle-mounted inverter according to any one of claims 1 to 4, characterized in that: The SPWM drive circuit includes a third chip, a first signal drive amplifier chip, a second signal drive amplifier chip and an amplifier circuit, the third chip is connected to the first signal drive amplifier chip and the second signal drive amplifier chip respectively, the first signal drive amplifier chip and the second signal drive amplifier chip are also connected to the amplifier circuit respectively, wherein, The third chip generates a first drive signal and a second drive signal. The first drive signal is amplified by the first signal driving amplifier chip and the amplifier circuit respectively, and the second drive signal is amplified by the second signal driving amplifier chip and the amplifier circuit respectively. The amplified first drive signal and the second drive signal respectively drive the voltage conversion module in the mainboard circuit to work.

6. The vehicle-mounted inverter according to any one of claims 1 to 5, characterized in that: The mainboard circuit also includes an auxiliary power circuit, an AC fault indication circuit, a leakage protection circuit, a fault indicator light circuit and a current feedback circuit, wherein: The auxiliary power circuit is connected to the transformer T1 and the third chip respectively, and is used to output auxiliary power of 15V and 5V to the third chip respectively; The AC fault indication circuit is connected to the second chip and the third chip respectively, and the AC fault indication circuit includes a second optical coupler for triggering an AC fault abnormality feedback signal and sending it to the second chip when receiving an enable signal from the third chip in the SPWM drive circuit; The fault indicator light circuit is connected to the second chip in the PWM drive circuit, and is used to control the fault indicator light to light up when the second chip receives the AC fault abnormality feedback signal and the leakage protection signal; A leakage protection circuit is used to cut off the power supply to protect the mainboard circuit when receiving a leakage protection signal; The current feedback circuit is connected to the negative terminal of the output end of the voltage conversion module and the third chip respectively, and is used to collect the output current of the mainboard circuit and send it to the third chip.

7. The vehicle-mounted inverter according to any one of claims 1 to 6, characterized in that: The mainboard circuit includes a first EMC absorption circuit and a second EMC absorption circuit, wherein: The input end of the first EMC absorption circuit is connected to the power supply module through a fuse, and the output end is connected to the DC boost module and the ACC switch respectively, so as to filter the input power supply and remove noise; The input end of the second EMC absorption circuit is connected to the voltage conversion module, and the output end is connected to the socket, and is used to filter out the electromagnetic radiation of the output voltage of the voltage conversion module.

8. The vehicle-mounted inverter according to claim 7, characterized in that: It also includes an input connector and input wire N1, a waterproof ring for the outlet hole and a lower shell N2, an insulating sheet N3, a waterproof ring N4, a PCB board N5, screws for locking the PCB board N6, an upper shell N7, screws for locking the upper and lower shells N8, an output wire and an output connector N9; wherein, During assembly, install the insulating sheet N3 on the bottom of the lower shell in the waterproof ring of the outlet hole and the lower shell N2, assemble the waterproof ring N4 on the four assembly edges of the lower shell in the waterproof ring of the outlet hole and the lower shell N2, complete the welding of the components on the PCB board N5, weld the input wires and output wires in the input connector and input line N1 and the output wires in the output connector N9 to the PCB board N5, and then assemble the welded PCB board N5 on the lower shell in the waterproof ring of the outlet hole and the lower shell N2, and fasten the PCB board N5 with the PCB board locking screw N6, and then assemble the upper shell N7. When assembling the upper shell N7, place the input wires and output wires in the input connector and input line N1 and the output wires in the output connector N9 on the outlet hole of the lower shell in the waterproof ring of the outlet hole and the lower shell N2, and then fasten the upper shell N7 and the lower shell in the waterproof ring of the outlet hole and the lower shell N2 with the upper and lower shell locking screws N8.

9. The vehicle-mounted inverter according to claim 8, characterized in that: It also includes a power socket, which includes a protective cover C1, a connecting rod C2, a panel and an upper shell C3, an LED lamp C4, a PCB board C5, a lower shell C6, and connecting screws C7 between the upper shell and the lower shell; wherein, During assembly, the protective cover C1 is assembled on the upper shell through the connecting rod C2, and the protective cover C1 is rotated and opened and closed using the connecting rod C2 as an axis. The terminals are welded on the PCB board C5, and the LED lamp C4 is fixed on the PCB board C5. Then the PCB board C5 is assembled into the panel and the upper shell C3, and then the lower shell C6 is assembled. The upper shell C3 and the lower shell C6 are buckled together and fastened by the connecting screws C7 of the upper shell and the lower shell.

10. The vehicle-mounted inverter according to claim 9, characterized in that: LED lamp C4 is connected to the fault indicator light circuit of the main board circuit, and is used to display the working status of the vehicle inverter, and when there are abnormal signals in the various signals collected by the second chip, different indication states are displayed based on different fault states.

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