CN104980056A - Full digital sine wave vehicle-mounted inverter and control method thereof - Google Patents

Abstract

The invention discloses a full digital sine wave vehicle-mounted inverter which comprises a DC/DC boost module, a DC/AC inverter module, a first drive module, a second drive module and a main control module. The DC/DC boost module converts low voltage direct current into high voltage direct current through push-pull boost. The DC/AC inverter module inverts high voltage direct current to alternating current. The first drive module receives a first PWM signal sent by the main control module and drives the DC/DC boost module according to the first PWM signal. The second drive module receives a second PWM signal sent by the main control module and drives the DC/AC inverter module according to the second PWM signal. The main control module detects whether a load is accessed and adjusts the duty cycle of the first PWM signal according to a detection result to start a load mode or a no-load mode. Compared with the prior art, the full digital sine wave vehicle-mounted inverter provided by the invention has the advantages that the extension upgrade capacity of the vehicle-mounted inverter is improved and no-load loss of the vehicle-mounted inverter is reduced. The invention further discloses a control method of the full digital sine wave vehicle-mounted inverter.

Description

Digital sinusoidal wave vehicle-mounted inverter and control method thereof

Technical field

The present invention relates to inverter technology field, relate to a kind of digital sinusoidal wave vehicle-mounted inverter and control method thereof more specifically.

Background technology

Vehicle-mounted inverter a kind ofly direct current energy can be converted to AC energy, be mainly used in device that is vehicle-mounted and other portable power source field.Divide by output waveform, vehicle-mounted inverter can be divided into repaiies sinewave inverter and sinewave inverter, and wherein sinewave inverter is because output waveform distortion is little, load capacity is high, obtains and applies more and more widely.Traditional sinewave inverter adopts the mode of hardware to produce drive singal usually, is namely compared by hardware generation sine wave reference and triangular wave, thus output drive signal.But, because hardware mode has the shortcomings such as circuit structure complexity, upgrade maintenance difficulty, the high and debugging difficulty of cost are large, be slowly digitally controlled in recent years and replace.The DC/AC inversion module of the DC/DC boost module that traditional digital control vehicle-mounted inverter forms primarily of KA7500/SG3525, sinusoidal wave integrated chip composition is formed.But, due to the restriction of control chip KA7500/SG3525, the often operating difficulties when carrying out Function Extension, performance upgrade to product, and dynamic voltage transient range is large, dynamic electric voltage transition is long for recovery time; And, due to the technical characteristic of KA7500/SG3525, make the DC/DC boost module of inverter be in standard-sized sheet ring operating state, cause inverter no-load loss large.

Summary of the invention

The object of the present invention is to provide a kind of digital sinusoidal wave vehicle-mounted inverter, to improve the expansion upgrading ability of vehicle-mounted inverter, reduce the no-load loss of vehicle-mounted inverter.

Another object of the present invention is to the control method that a kind of digital sinusoidal wave vehicle-mounted inverter is provided, to reduce the no-load loss of vehicle-mounted inverter.

For achieving the above object, the invention provides a kind of digital sinusoidal wave vehicle-mounted inverter, comprise DC/DC boost module, DC/AC inversion module, the first driver module, the second driver module and main control module, wherein said DC/DC boost module is used for, by recommending boosting, the low-voltage DC of input is converted to high voltage direct current; It is alternating current that described DC/AC inversion module is used for described high voltage direct current inversion; Described first driver module is connected with described main control module and described DC/DC boost module, for receiving the first pwm signal that described main control module sends and driving described DC/DC boost module according to described first pwm signal; Described second driver module is connected with described main control module and described DC/AC inversion module, for receiving the second pwm signal that described main control module sends and driving described DC/AC inversion module according to described second pwm signal; Whether described main control module accesses load and the duty ratio arranging described first pwm signal when access load being detected is preset maximum value with the duty ratio entering load model and downgrade described first pwm signal when detecting and not accessing load gradually to predetermined minimum to enter idle mode for detecting.

Compared with prior art, the digital sinusoidal wave vehicle-mounted inverter of the present invention comprises DC/DC boost module, DC/AC inversion module, the first driver module, the second driver module and main control module, wherein DC/DC boost module is for recommending booster circuit, circuit structure is easily expanded, thus comparatively easy when Function Extension, performance upgrade carried out to vehicle-mounted inverter, avoid the restriction to circuit expansion and upgrading of control chip in prior art; Simultaneously, main control module downgrades the first pwm signal duty ratio when detecting and not accessing load (namely unloaded) is that predetermined minimum is with forbidden energy DC/DC boost module, and the duty ratio arranging the first pwm signal when load being detected is preset maximum value, thus reduce the no-load loss of vehicle-mounted inverter.

Preferably, described DC/DC boost module comprises boosting unit and rectification unit, described boosting unit is used for changing described low-voltage DC into High Level AC Voltage, it is described high voltage direct current by described high-voltage alternating electric rectification that described rectification unit is used for, and described boosting unit comprise multiple structure identical recommend translation circuit.

Preferably, recommend translation circuit described in comprise first and recommend translation circuit, second recommends translation circuit, 3rd recommends translation circuit and the 4th recommends translation circuit, and wherein said first recommends translation circuit comprises transformer T10, field effect transistor Q11, Q12, Q13, Q14, electric capacity C11 and resistance R10, R11, R12, R13, the grid of R14, described field effect transistor Q11 and Q12 is respectively by described resistance R10, resistance R11 is connected with described first driver module, the drain electrode of described field effect transistor Q11 and Q12 is connected to pin 7 and the pin 8 of described transformer T10 jointly, described field effect transistor Q13 is connected with described first driver module 13 with resistance R13 respectively by described resistance R12 with the grid of Q14, the drain electrode of described field effect transistor Q13 and Q14 is connected to pin 1 and the pin 2 of described transformer T10, described field effect transistor Q11 jointly, Q12, Q13, the source ground of Q14, described electric capacity C11 and described resistance R14 is parallel between the drain electrode of described field effect transistor Q11 and the drain electrode of described field effect transistor Q13 after connecting, the pin 3 of described transformer T10, 4, 5, 6 are electrically connected with described low-voltage direct, and the pin 9 of described transformer T10 is connected with the first input end of pin 10 with described rectification unit, and the pin 12 of described transformer T10 is recommended translation circuit with pin 13 and described second and is connected.

Preferably, described digital sinusoidal wave vehicle-mounted inverter also comprises:

Sampling module, described sampling module is for gathering output voltage values and the output current value of described alternating current;

Human-computer interaction module, described human-computer interaction module be used for described main control module with communicate between external equipment and show the running parameter of described digital sinusoidal wave vehicle-mounted inverter;

Short circuit protection module, described short circuit protection module is connected with described DC/AC inversion module, described second driver module and described main control module, for carrying out short-circuit protection.

Preferably, described human-computer interaction module comprises RS-485 communication unit and LCD display unit, and described RS485 communication unit is connected between described main control module and described external equipment, and described LCD display unit is connected with described main control module.

Preferably, described sampling module comprises voltage isolation sampling unit and electric current isolation sampling unit, described voltage isolation sampling unit comprises voltage transformer T1, operational amplifier U5, diode D50, D51, D52, electric capacity C50 and resistance R50, R51 ~ R510, described resistance R50 with R51 connects and one end after series connection is connected with the pin 4 of described voltage transformer T1, the other end is connected with the zero line of described alternating current, described resistance R52 with R53 connects and one end after series connection is connected with the pin 3 of described voltage transformer T1, the other end is connected with the live wire of described alternating current, described resistance R54, between the pin 1 that diode D50 and electric capacity C50 is parallel to described voltage transformer T1 and pin 2, described resistance R55 is series between the pin 1 of voltage transformer T1 and the pin 3 of described operational amplifier U5, described resistance R56 is connected between the pin 2 of operational amplifier U5 and pin 1, the pin 1 of described operational amplifier U5 simultaneously with described resistance R57, one end of R58 and the pin 10 of described operational amplifier U5 connect, the other end ground connection of described resistance R57, the other end of described resistance R58 is connected with one end of the pin 6 of described operational amplifier U5 and described resistance R59, the pin 7 of described operational amplifier U5 is connected with the anode of described diode D51, the negative electrode of described diode D51 be connected with the other end of described resistance R59 and coating-forming voltage feedback end to feed back described output voltage values to described main control module, the pin 9 of described operational amplifier U5 is connected with described pressure feedback port, and the pin 8 of described operational amplifier U5 is connected with the anode of diode D52, the negative electrode of described diode D52 is connected with one end of described pressure feedback port and described resistance R510, the other end ground connection of described resistance R510.

Preferably, described short circuit protection module comprises resistance R60, R61 ~ R613, diode D60 ~ D64, electric capacity C60 ~ C62, triode Q60, photoelectrical coupler U21 and operational amplifier U22, one end of described resistance R60 is connected with the short-circuit detecting end of described DC/AC inversion module, the other end of described resistance R60 is connected with the anode of one end of described electric capacity C60 and described diode D60, the negative electrode of described diode D60 and described resistance R61, one end of described electric capacity C61 and the pin 3 of described operational amplifier U22 connect, described electric capacity C60, the other end ground connection of C61 and resistance R61, pin 2 and the described resistance R62 of described operational amplifier U22, one end of R63 connects, the other end ground connection of described resistance R63, the other end of described resistance R62 is connected with+5V power supply, pin 1 and the described diode D61 of described operational amplifier U22, the anode of D62 and one end of described resistance R64 connect, the negative electrode of described diode D62 connect after described resistance R65 with the pin 5 of described operational amplifier U22, the other end of described resistance R64, the negative electrode of described diode D63 and one end of described electric capacity C62 connect, the anode of described diode D63 is connected with the pin 7 of operational amplifier U22, the other end ground connection of electric capacity C62, the pin 7 of operational amplifier U22 is connected with the anode of described diode D64, the negative electrode of described diode D64 is connected with the negative electrode of one end of described resistance R68 and described diode D61, the anode of described diode D61 is connected with the pin 1 of described operational amplifier U22, the other end of described resistance R68 is connected with the base stage of described triode Q60, the grounded emitter of described triode Q60, the collector electrode of described triode Q60 is connected with the pin 2 of described photoelectrical coupler U21, the pin 1 of described photoelectrical coupler U21 is connected with+12V power supply after described resistance R69 and the pin 1 of described photoelectrical coupler U21 is connected with described resistance R610 in parallel between pin 2, the pin 4 of described photoelectrical coupler U21 is connected after described resistance R611 and is connected with+5V power supply, the pin 3 of described photoelectrical coupler U21 is connected with one end of described resistance R612 and described resistance R613, the other end ground connection of described resistance R613, the other end of resistance R612 is connected with described second driver module and described main control module.

Preferably, the first driver module is stated and described second driver module is optical couple isolation drive circuit.

Preferably, described first pwm signal comprises pwm signal PWM1 and PWM2, described first driver module comprises optocoupler driving chip U7, U8 and resistance R30, R31, R32, R33, the pin 2 of described optocoupler driving chip U7 is connected with one end of described resistance R31, the other end of described resistance R31 is connected to receive the pwm signal PWM1 that described main control module exports with described main control module, described resistance R30 is parallel between the other end of described resistance R31 and the pin 4 of described optocoupler driving chip U7, the pin 6 of described optocoupler driving chip U7 and pin 7 link together and drive singal PWM1_0 after output processing to described DC/DC boost module, the pin 2 of described optocoupler driving chip U8 is connected with one end of described resistance R33, the other end of described resistance R33 is connected to receive the pwm signal PWM2 that described main control module exports with described main control module, described resistance R32 is parallel between the other end of described resistance R33 and the pin 4 of described optocoupler driving chip U8, the pin 6 of described optocoupler driving chip U8 and pin 7 link together and drive singal PWM2_0 after output processing to described DC/DC boost module.

Invention also provides a kind of control method of digital sinusoidal wave vehicle-mounted inverter, comprise the following steps:

Gather output current value to judge exporting whether have load;

If judged result is for there being load, then the duty ratio that the first pwm signal is set be preset maximum value to enter load model, if judged result is non-loaded, then the duty ratio downgrading described first pwm signal gradually to predetermined minimum to enter idle mode.

Preferably, described collection output current value is to judge output also comprises before whether having load:

Judge low-voltage DC input voltage whether in rated range;

If the determination result is YES, then soft start DC/DC boost module and DC/AC inversion mould successively, if judged result is no, then closes described DC/DC boost module to enter protected mode.

Preferably, the described duty ratio arranging described first pwm signal is that preset maximum value also comprises after entering load model:

Real-time Collection output voltage values and described output current value;

Regulate the duty ratio of described first pwm signal and the second pwm signal to adjust described output voltage values and described output current value in real time according to the PI control method of described output voltage values, described output current value and default outer voltage and current inner loop.

By following description also by reference to the accompanying drawings, the present invention will become more clear, and these accompanying drawings are for explaining embodiments of the invention.

Accompanying drawing explanation

Fig. 1 is the structured flowchart of digital sinusoidal wave vehicle-mounted inverter one embodiment of the present invention.

Fig. 2 is the structured flowchart of digital sinusoidal wave another embodiment of vehicle-mounted inverter of the present invention.

Fig. 3 is the circuit diagram of main control module and human-computer interaction module in Fig. 2.

Fig. 4 is the circuit diagram of DC/DC boost module in Fig. 2.

Fig. 5 is the circuit diagram of DC/AC inversion module in Fig. 2.

Fig. 6 is the circuit diagram of the first driver module in Fig. 2.

Fig. 7 is the circuit diagram of the second driver module in Fig. 2.

Fig. 8 is the circuit diagram of sampling module in Fig. 2.

Fig. 9 is the circuit diagram of short circuit protection module in Fig. 2.

Figure 10 is the circuit diagram of temperature protection module in Fig. 2.

Figure 11 is the circuit diagram of power module in the digital sinusoidal wave vehicle-mounted inverter of the present invention.

Figure 12 is the flow chart of the control method of the digital sinusoidal wave vehicle-mounted inverter of the present invention.

Embodiment

With reference now to accompanying drawing, describe embodiments of the invention, element numbers similar in accompanying drawing represents similar element.

Please refer to Fig. 1, the digital sinusoidal wave vehicle-mounted inverter 100 of the present invention comprises DC/DC boost module 11, DC/AC inversion module 12, first driver module 13, second driver module 14 and main control module 10.Wherein, DC/DC boost module 11 is for being converted to high voltage direct current HVO by recommending boosting by the low-voltage DC of input; DC/AC inversion module 12 is for being alternating current AC by high voltage direct current inversion; First driver module 13 is connected with main control module 10 and DC/DC boost module 11, for receiving the first pwm signal that main control module 10 sends and driving DC/DC boost module 11 according to the first pwm signal; Second driver module 14 is connected with main control module 10 and DC/AC inversion module 12, for receiving the second pwm signal that main control module 10 sends and driving DC/AC inversion module 12 according to the second pwm signal; Whether main control module 10 accesses load and the duty ratio arranging the first pwm signal when access load being detected is preset maximum value with the duty ratio entering load model and downgrade the first pwm signal when detecting and not accessing load gradually to predetermined minimum to enter idle mode for detecting.Wherein, under load model, the duty ratio of the first pwm signal is maximum, the duty ratio of the first pwm signal minimum (being about 3% in the present embodiment) under idle mode.

Compared with prior art, the digital sinusoidal wave vehicle-mounted inverter 100 of the present invention comprises DC/DC boost module 11, DC/AC inversion module 12, first driver module 13, second driver module 14 and main control module 10, wherein DC/DC boost module 11 is for recommending booster circuit, circuit structure is easily expanded, thus comparatively easy when Function Extension, performance upgrade carried out to vehicle-mounted inverter, avoid the restriction of control chip; Simultaneously, main control module 10 downgrades the first pwm signal duty ratio when detecting and not accessing load (namely unloaded) is predetermined minimum and forbidden energy DC/DC boost module, and the duty ratio arranging the first pwm signal when load being detected is preset maximum value drives the work of DC/DC boost module, reduce the no-load loss of vehicle-mounted inverter.

Please refer to Fig. 2, in another preferred embodiment, the digital sinusoidal wave vehicle-mounted inverter 100 of the present invention also comprises sampling module 15, short circuit protection module 16, human-computer interaction module 17 and temperature protection module 18, and wherein sampling module 15 is for gathering output voltage values (i.e. the magnitude of voltage of alternating current) and the output current value of digital sinusoidal wave vehicle-mounted inverter 100; Short circuit protection module 16 is for carrying out short-circuit protection when short circuit; Human-computer interaction module 17 for show main control module 10 sample the digital sinusoidal wave vehicle-mounted inverter 100 obtained running parameter and external equipment is communicated with main control module 10; Temperature protection module 18 is for starting fan with cooling when temperature is too high.Concrete, as shown in Figure 8, sampling module 15 comprises voltage isolation sampling unit 151 and electric current isolation participates in unit 153; As shown in Figure 3, human-computer interaction module 17 comprises RS485 communication unit 171 and LCD display unit 173.

The realizing circuit of modules in Fig. 2 is described in detail below with reference to Fig. 3 to Figure 10.

Concrete, as shown in Figure 3, main control module 10 comprises Master control chip U0, indicator unit 101, buzzer unit 103, resistance R01, R02 ... R08, electric capacity C01, C02 ... C011 and crystal oscillator Y01.Wherein, the pin 1 of Master control chip U0, 2, 44 are connected with RS485 communication unit 171, the pin 36 of Master control chip U0, 14, 15, 3 are connected with the second driver module 14, for output pwm signal SPW_A, SPW_B, SPW_C, SPW_D to the second driver module 14, the pin 4 of Master control chip U0, 24, 26, 27, 37 to 43 are connected with LCD display unit 173, the pin 5 of Master control chip U0, 10, 11 are connected with indicator unit 101, pin 6 ground connection of Master control chip U0 and pin 7 are connected with+5V power supply, the pin 8 of Master control chip U0 is connected with short circuit protection module 16, for receiving short-circuit signal SHORT_IN, the pin 20,21 of Master control chip U0 is isolated sampling unit 151 and electric current respectively and is isolated sampling unit 153 and be connected with voltage, the pin 22 of Master control chip U0 obtains the current temperature value of vehicle-mounted inverter 100 for input sample, the pin 19 of Master control chip U0 is for detecting the magnitude of voltage of low-voltage DC (being battery in the present embodiment), the pin 25 of Master control chip U0 is connected with temperature protection module 18, for starting according to the current temperature value control temperature protection module 18 of vehicle-mounted inverter 100 or not start-up temperature protection.Wherein, indicator unit 101 comprises LED LED01, LED01 and LED03, and three LED are respectively red, green and yellow, and indicator unit 101 can indicate the operating state of inverter 100; Buzzer unit 103 comprises buzzer BUZ, resistance R09 and triode Q01, be connected with the pin 23 of Master control chip U0 after the base series resistor R09 of wherein triode Q01, the grounded emitter of triode Q01, the collector electrode of triode Q01 is connected with one end of buzzer BUZ, the other end of buzzer BUZ is connected with+12V power supply, and buzzer unit 103 is for the abnormal alarm that works at inverter 100.In addition, each resistance in main control module 10, the annexation of electric capacity, specifically see Fig. 3, do not describe in detail herein.

As shown in Figure 4, DC/DC boost module 11 comprises boosting unit 111 and rectification unit 113, and wherein boosting unit 111 is for changing the low-voltage DC of input into High Level AC Voltage, and rectification unit 113 is for being high voltage direct current HVO by high-voltage alternating electric rectification.Concrete, boosting unit 111 comprise multiple structure identical recommend translation circuit, in the present embodiment, boosting unit 111 comprises first and recommends translation circuit, second and recommend translation circuit, the 3rd and recommend translation circuit and the 4th and recommend translation circuit.Wherein, first recommends translation circuit comprises transformer T10, field effect transistor Q11, Q12, Q13, Q14, electric capacity C11 and resistance R10, R11, R12, R13, R14, and in the present embodiment, the model of transformer T10 is EE4220.Concrete, the grid of field effect transistor Q11 and Q12 is respectively by resistance R10, resistance R11 is connected with the first driver module 13 (in Fig. 4, signal PWM_H corresponds to signal PWM1_0 in Fig. 6), the drain electrode of field effect transistor Q11 and Q12 is connected to pin 7 and the pin 8 of transformer T10 jointly, field effect transistor Q13 is connected with the first driver module 13 (in Fig. 4, signal PWM_L corresponds to signal PWM2_0 in Fig. 6) with resistance R13 respectively by resistance R12 with the grid of Q14, the drain electrode of field effect transistor Q13 and Q14 is connected to pin 1 and the pin 2 of transformer T10 jointly, field effect transistor Q11, Q12, Q13, the source ground of Q14, electric capacity C11 and resistance R14 is parallel between the drain electrode of field effect transistor Q11 and the drain electrode of field effect transistor Q13 after connecting, the pin 3 of transformer T10, 4, 5, 6 (is the battery supply of+12V in the present embodiment with outside low-voltage DC, as shown in BT+12V in Fig. 4) connect, the pin 9 of transformer T10 is connected with the first input end of pin 10 with rectification unit 113, the pin 12 of transformer T10 is recommended translation circuit with pin 13 and second and is connected.Wherein second recommend translation circuit, the 3rd and recommend translation circuit and the 4th and recommend translation circuit and first to recommend the circuit structure of translation circuit identical.Concrete, second recommends translation circuit comprises transformer T11, field effect transistor Q15, Q16, Q17, Q18, electric capacity C12 and resistance R15, R16, R17, R18, R19, wherein pin 9 and the pin 10 and first of transformer T11 recommend the pin 12 of transformer T10 in translation circuit and pin 13 is connected, and the pin 12 of transformer T11 is recommended translation circuit with pin 13 and the 3rd and is connected; 3rd recommends translation circuit comprises transformer T12, field effect transistor Q19, Q110, Q111, Q112, electric capacity C13 and resistance R110, R111, R112, R113, R114, wherein pin 9 and the pin 10 and second of transformer T12 recommend the pin 12 of transformer T11 in translation circuit and pin 13 is connected, and the pin 12 of transformer T12 is recommended translation circuit with pin 13 and the 4th and is connected; 4th recommends translation circuit comprises transformer T13, field effect transistor Q113, Q114, Q115, Q116, electric capacity C14 and resistance R115, R116, R117, R118, R119, wherein pin 9 and the pin 10 and the 3rd of transformer T13 recommend the pin 12 of transformer T12 in translation circuit and pin 13 is connected, and the pin 12 of transformer T13 is connected with the second input of rectification unit 113 with pin 13.It should be noted that, the voltage of the high voltage direct current HVO obtained as required, boosting unit 111 can comprise multiplely recommends translation circuit, and be not restricted to 4, and respectively recommend annexation between translation circuit as shown in Figure 4, compared with prior art, DC/DC boost module 11 of the present invention is not made up of an integrated chip (as control chip KA7500/SG3525), but be made up of multiple translation circuit of recommending, thus the restriction of the uncontrolled chip KA7500/SG3525 of DC/DC boost module 11, Function Extension and performance upgrade can be carried out easily.

Please refer to Fig. 4 again, rectification unit 113 comprises diode D10, D11, D12, D13, electric capacity C15, C16, resistance R120 and fuse F10, F11, F12, wherein diode D10, D11, D12, D13 is connected to form bridge rectifier, electric capacity C15, C16 and resistance R120 is connected between the positive output end of bridge rectifier and negative output terminal, fuse F10, F11, in parallel and the one end after parallel connection of F12 is connected with the positive output end of bridge rectifier, the other end after parallel connection is connected with DC/AC inversion module 12, and the negative output terminal ground connection of bridge rectifier.During work, low-voltage direct electric boost is obtained high voltage direct current by DC/DC boost module 11 under the driving of the first driver module 13.

As shown in Figure 5, DC/AC inversion module 12 comprises field effect transistor Q20, Q21, Q22, Q23, Q24, Q25, Q26, Q27, inductance L 21, L22, diode D21, D22, D23, D24, electric capacity C21, C22, C23, C24, C25, C26, resistance R20, R21.......R223, R224.Wherein, diode D21 is in parallel with resistance R24, and the negative electrode of diode D21 is connected with the signal output part Q1G of the second drive circuit 14, to receive the control signal Q1G that the second drive circuit 14 exports, the anode of diode D21 is respectively by resistance R20, resistance R23 and field effect transistor Q20, the grid of Q21 connects, the drain electrode of field effect transistor Q20 and Q21 and the output of DC/DC boost module 11 (export high voltage direct current HVO, the voltage of the present embodiment mesohigh direct current HVO is 400V) connect, parallel resistance R21 between the grid of field effect transistor Q20 and source electrode, parallel resistance R22 between the grid of field effect transistor Q21 and source electrode, and the source electrode of the source electrode of field effect transistor Q20 and field effect transistor Q21 is connected with the signal output part Q1S of the second drive circuit 14, to receive the control signal Q1S that the second drive circuit 14 exports, diode D22 is in parallel with resistance R29, and the negative electrode of diode D22 is connected with the signal output part Q2G of the second drive circuit 14, to receive the control signal Q2G that the second drive circuit 14 exports, the anode of diode D22 is respectively by resistance R25, resistance R28 and field effect transistor Q22, the grid of Q23 connects, field effect transistor Q22 is connected with the source electrode of field effect transistor Q20 and the source electrode of field effect transistor Q21 respectively with the drain electrode of field effect transistor Q23, parallel resistance R26 between the grid of field effect transistor Q22 and source electrode, parallel resistance R27 between the grid of field effect transistor Q23 and source electrode, and the source electrode of field effect transistor Q22 is connected with the source electrode of field effect transistor Q23, electric capacity C21 is parallel between the drain electrode of field effect transistor Q20 and the source electrode of field effect transistor Q22, diode D23 is in parallel with resistance R215, and the negative electrode of diode D23 is connected with the signal output part Q3G of the second drive circuit 14, to receive the control signal Q3G that the second drive circuit 14 exports, the anode of diode D23 is respectively by resistance R211, resistance R214 and field effect transistor Q24, the grid of Q25 connects, the drain electrode of field effect transistor Q24 is connected with the output of the drain electrode of field effect transistor Q25 with DC/DC boost module 11, parallel resistance R210 between the grid of field effect transistor Q24 and source electrode, parallel resistance R213 between the grid of field effect transistor Q25 and source electrode, and the source electrode of the source electrode of field effect transistor Q24 and field effect transistor Q25 is connected with the signal output part Q3S of the second drive circuit 14, to receive the control signal Q3S that the second drive circuit 14 exports, electric capacity C22 is parallel between the source electrode of field effect transistor Q22 and the drain electrode of field effect transistor Q24, diode D24 is in parallel with resistance R220, and the negative electrode of diode D24 is connected with the signal output part Q4G of the second drive circuit 14, to receive the control signal Q4G that the second drive circuit 14 exports, the anode of diode D24 is respectively by resistance R217, resistance R219 and field effect transistor Q26, the grid of Q27 connects, field effect transistor Q26 is connected with the source electrode of field effect transistor Q24 and the source electrode of field effect transistor Q25 respectively with the drain electrode of field effect transistor Q27, parallel resistance R216 between the grid of field effect transistor Q26 and source electrode, parallel resistance R218 between the grid of field effect transistor Q27 and source electrode, and the source electrode of field effect transistor Q26 is connected with the source electrode of field effect transistor Q27, resistance R221, resistance R222, one end ground connection after resistance R223 and resistance R224 parallel connection, the other end is connected with the source electrode of field effect transistor Q26, one end of inductance L 21 is connected with the signal output part Q1S of the second driver module 14, the other end of inductance L 21 is connected with the pin 3 of one end of electric capacity C23 and inductance L 22, the other end of electric capacity C23 is connected with the signal output part Q3S of the pin 4 of inductance L 22 and the second driver module 14, shunt capacitance C24 between the pin 1 of inductance L 22 and pin 2, electric capacity C25 and electric capacity C26 is parallel to the two ends of electric capacity C24 after connecting, and the voltage at electric capacity 24 two ends is respectively live wire AC_L and the zero line AC_N of the alternating current AC that inversion obtains.

During work, high voltage direct current HVO inversion is alternating current AC by DC/AC inversion module 12 under the control of the second driver module 14, and boosting through DC/DC boost module 11 in the present embodiment, to process the high voltage direct current obtained be 400V.Compared with prior art, DC/AC inversion module 12 of the present invention is not made up of sinusoidal wave integrated chip, but be made up of transformer and multiple field effect transistor, because DC/AC inversion module 12 is connected to form by simple components and parts, thus by the restriction of sinusoidal wave integrated chip, can not can carry out Function Extension and performance upgrade easily.

First driver module 13 and the second driver module 14 are optical couple isolation drive circuit, and fail safe is higher.As shown in Figure 6, the first driver module 13 comprises optocoupler driving chip U7, U8, resistance R30, R31, R32, R33 and electric capacity C30, C31, C32, C33.Wherein, the pin 1 of optocoupler driving chip U7 is connected with+12V power supply with pin 8; One end of electric capacity C30 with C31 is connected with+12V power supply, other end ground connection; The pin 2 of optocoupler driving chip U7 is connected with one end of resistance R31, and the other end of resistance R31 is connected with one end of Master control chip U0 and resistance R30, the other end ground connection of resistance R30, and optocoupler driving chip U7 receives the pwm signal PWM1 that Master control chip U0 sends; The pin 6 of optocoupler driving chip U7 and pin 7 link together and drive singal PWM1_0 to DC/DC boost module 11 after output processing; The pin 4 of optocoupler driving chip U7 and pin 5 ground connection; In like manner, the pin 1 of optocoupler driving chip U8 is connected with+12V power supply with pin 8; One end of electric capacity C32 with C33 is connected with+12V power supply, other end ground connection; The pin 2 of optocoupler driving chip U8 is connected with one end of resistance R33, and the other end of resistance R33 is connected with one end of Master control chip U0 and resistance R32, the other end ground connection of resistance R32, and optocoupler driving chip U8 receives the pwm signal PWM2 that Master control chip U0 sends; The pin 6 of optocoupler driving chip U8 and pin 7 link together and drive singal PWM2_0 to DC/DC boost module 11 after output processing; The pin 4 of optocoupler driving chip U8 and pin 5 ground connection.It should be noted that, pwm signal PWM1 and PWM2 forms the first pwm signal jointly, first pwm signal is output drive signal PWM1_0 and PWM2_0 to DC/DC boost module 11 after the first driver module 13 processes, in order to whether to drive the work of DC/DC boost module 11.Concrete, Master control chip U0 can the operating state of control DC/DC boost module 11 by the duty ratio of adjustment first pwm signal (PWM1 and PWM2).

As shown in Figure 7, the second drive circuit 14 comprises optocoupler driving chip U1, optocoupler driving chip U2, optocoupler driving chip U3, optocoupler driving chip U4, diode D40, D41, D42, triode Q40, Q41, Q42, electric capacity C40, C41, C42, C43, C44, C45 and resistance R40, R41, R42, R43, R44, R45.Wherein the model of optocoupler driving chip U1, optocoupler driving chip U2, optocoupler driving chip U3, optocoupler driving chip U4 is TLP250.Concrete, optocoupler driving chip U1, U2, U3, the pin 1 of U4 is all connected with+5V power supply with pin 2, the drive singal output pin of Master control chip U0 is connected to after the pin 3 series resistance R40 of optocoupler driving chip U1, in order to receive the pwm signal SPWM_A that Master control chip U0 exports, the pin 5 of optocoupler driving chip U1 forms signal output part Q1S and exports control signal Q1S to DC/AC inversion module 12, the pin 6 of optocoupler driving chip U1 and pin 7 are joined together to form signal output part Q1G and export control signal Q1G to DC/AC inversion module 12, the pin 8 of optocoupler driving chip U1 is connected with one end of the negative electrode of diode D40 and electric capacity C41, the other end ground connection of electric capacity C41, the anode of diode D40 is connected with+12V power supply, the pin 3 of optocoupler driving chip U2 is connected with the collector electrode of triode Q40, the drive singal output pin of Master control chip U0 is connected to after the emitter series resistance R41 of triode Q40, in order to receive the pwm signal SPWM_B that Master control chip U0 exports, pin 5 ground connection of optocoupler driving chip U2, the pin 6 of optocoupler driving chip U2 and pin 7 are joined together to form signal output part Q2G and export control signal Q2G to DC/AC inversion module 12, and the pin 8 of optocoupler driving chip U2 is connected with+12V power supply, the drive singal output pin of Master control chip U0 is connected to after the pin 3 series resistance R42 of optocoupler driving chip U3, in order to receive the pwm signal SPWM_C that Master control chip U0 exports, the pin 5 of optocoupler driving chip U3 forms signal output part Q3S and exports control signal Q3S to DC/AC inversion module 12, the pin 6 of optocoupler driving chip U3 and pin 7 are joined together to form signal output part Q3G and export control signal Q3G to DC/AC inversion module 12, the pin 8 of optocoupler driving chip U3 is connected with one end of the negative electrode of diode D41 and electric capacity C43, the other end of electric capacity C43 is connected with the pin 5 of optocoupler driving chip U3, the anode of diode D41 is connected with+12V power supply, the pin 3 of optocoupler driving chip U4 is connected with the collector electrode of triode Q41, the drive singal output pin of Master control chip U0 is connected to after the emitter series resistance R43 of triode Q41, in order to receive the pwm signal SPWM_D that Master control chip U0 exports, pin 5 ground connection of optocoupler driving chip U2, the pin 6 of optocoupler driving chip U2 and pin 7 are joined together to form signal output part Q4G and export control signal Q4G to DC/AC inversion module 12, the pin 8 of optocoupler driving chip U2 is connected with+12V power supply, the base stage of triode Q40 and the collector electrode of triode Q42, the base stage of triode Q41 and one end of resistance R44 connect, the other end of resistance R44 is connected with+5V power supply, the grounded emitter of triode Q42, the base stage of triode Q42 is connected with the negative electrode of diode D42, the anode of diode D42 is connected to short circuit protection module 16 after connecting with resistance R45, in order to receive the short-circuit protection signal SHORT_IN that short circuit protection module 16 exports.Wherein, pwm signal SPWM_A, SPWM_B, SPWM_C, SPWM_D form the second pwm signal jointly, and the second pwm signal outputs control signals to DC/AC inversion module 12 after the second driver module 14 processes, and whether works in order to drive DC/AC inversion module 12.Concrete, Master control chip U0 can the operating state of control DC/AC inversion module 12 by the duty ratio of adjustment second pwm signal.

As shown in Figure 8, sampling module 15 comprises voltage isolation sampling unit 151 and electric current isolation sampling unit 153.Wherein, voltage isolation sampling unit 151 comprises voltage transformer T1, operational amplifier U5, diode D50, D51, D52, electric capacity C50 and resistance R50, R51 ... R510.Concrete, the alternating current AC of a winding parallel access DC/AC inversion module 12 output of voltage transformer T1, operational amplifier U5, diode D50, D51, D52, electric capacity C50 and resistance R50, R51 ... R510 forms feedback circuit in the secondary winding side of voltage transformer T1, for the output voltage values (corresponding with the magnitude of voltage of alternating current AC) obtained of sampling is fed back to Master control chip U0.More specifically, resistance R50 connects mutually with resistance R51 and one end after connecting is connected with the pin 4 of voltage transformer T1, the other end is connected with the zero line AC_N of alternating current AC, resistance R52 connects mutually with resistance R53 and one end after connecting is connected with the pin 3 of voltage transformer T1, the other end is connected with the live wire AC_L of alternating current AC, resistance R54, diode D50 and electric capacity C50 is parallel to (i.e. the two ends of secondary winding) between the pin 1 of voltage transformer T1 and pin 2, resistance R55 is series between the pin 1 of voltage transformer T1 and the pin 3 (wherein an in-phase input end) of operational amplifier U5, resistance R56 is connected between the pin 2 (corresponding inverting input) of operational amplifier U5 and pin 1 (output), the pin 1 of operational amplifier U5 simultaneously with resistance R57, one end of resistance R58 and the pin 10 of operational amplifier U5 connect, the other end ground connection of resistance R57, the other end of resistance R58 is connected with one end of the pin 6 of operational amplifier U5 and resistance R59, the pin 7 of operational amplifier U5 is connected with the anode of diode D51, the negative electrode of diode D51 is connected with the other end of resistance R59 and coating-forming voltage feedback end (VFB_IN), the pin 9 of operational amplifier U5 is connected with pressure feedback port, and the pin 8 of operational amplifier U5 is connected with the anode of diode D52, the negative electrode of diode D52 is connected with one end of pressure feedback port and resistance R510, the other end ground connection of resistance R510.It should be noted that, U5A, U5B and U5C shown in Fig. 8 form operational amplifier U5 jointly, and in the present embodiment, operational amplifier U5 is four-operational amplifier, and if model is the operational amplifier of LM324A, in addition, the model of voltage transformer T1 is ZMPT107.

Please refer to Fig. 8 again, electric current isolation sampling unit 153 comprises current transformer T2, operational amplifier U6, diode D53, D54, D55, electric capacity C51 and resistance R511, R512.......R517.Wherein, a winding side joint of current transformer T2 enters the outlet line (not shown in FIG.) of vehicle-mounted inverter 100, for responding to the output current value in outlet line, operational amplifier U6, diode D53, D54, D55, electric capacity C51 and resistance R511, R512.......R517 form feedback circuit in the secondary winding side of current transformer T2, for feeding back to Master control chip U0 by responding to the output current value obtained.Concrete, resistance R511, diode D53 and electric capacity C51 is parallel to (i.e. the two ends of secondary winding) between the pin 1 of current transformer T2 and pin 2, resistance R512 is series between the pin 1 of current transformer T2 and the pin 3 (wherein an in-phase input end) of operational amplifier U6, resistance R513 is connected between the pin 2 (corresponding inverting input) of operational amplifier U6 and pin 1 (output), the pin 1 of operational amplifier U6 simultaneously with resistance R514, one end of resistance R515 and the pin 10 of operational amplifier U6 connect, the other end ground connection of resistance R514, the other end of resistance R515 is connected with one end of the pin 6 of operational amplifier U6 and resistance R516, the pin 7 of operational amplifier U6 is connected with the anode of diode D54, the negative electrode of diode D54 is connected with the other end of resistance R516 and forms current feedback terminal (IFB_IN), the pin 9 of operational amplifier U6 is connected with current feedback terminal, and the pin 8 of operational amplifier U6 is connected with the anode of diode D55, the negative electrode of diode D55 is connected with one end of current feedback terminal and resistance R517, the other end ground connection of resistance R517.Wherein, U6A, U6B and U6C shown in Fig. 8 form operational amplifier U6 jointly, and in the present embodiment, operational amplifier U6 is four-operational amplifier, and if model is the operational amplifier of LM324A, in addition, in the present embodiment, the model of current transformer T2 is ZMCT102.

As shown in Figure 9; short circuit protection module 16 comprises resistance R60, R61.......R615, diode D60, D61, D62, D63, D64, electric capacity C60, C61, C62, C63, triode Q60, pressurizer U20, photoelectrical coupler U21 and operational amplifier U22; preferably; the model of pressurizer U20 is 78L05; the model of photoelectrical coupler U21 is EL817, and the model of operational amplifier U22 is LM358N.Concrete, one end of resistance R60 is connected with the short-circuit detecting end (IFB_3) of DC/AC inversion module 12, the other end of resistance R60 is connected with the anode of one end of electric capacity C60 and diode D60, the negative electrode of diode D60 and resistance R61, one end of electric capacity C61 and the pin 3 of operational amplifier U22 connect, electric capacity C60, the other end ground connection of resistance R61 and electric capacity C61, the pin 2 of operational amplifier U22 is connected with one end of resistance R62 and resistance R63, the other end ground connection of resistance R63, the other end of resistance R62 is connected with+5V power supply, pin 1 and the diode D61 of operational amplifier U22, the anode of D62 and one end of resistance R64 connect, with the pin 5 of operational amplifier U22 after the negative electrode series resistance R65 of diode D62, the other end of resistance R64, the negative electrode of diode D63 and one end of electric capacity C62 connect, the anode of diode D63 is connected with the pin 7 of operational amplifier U22, the other end ground connection of electric capacity C62, the pin 7 of operational amplifier U22 is connected with the anode of diode D64, the negative electrode of diode D64 is connected with the negative electrode of one end of resistance R68 and diode D61, the anode of diode D61 is connected with the pin 1 of operational amplifier U22, the other end of resistance R68 is connected with the base stage of triode Q60, the grounded emitter of triode Q60, the collector electrode of triode Q60 is connected with the pin 2 of photoelectrical coupler U21, the pin 1 of photoelectrical coupler U21 is with parallel resistance R610 between pin 2 and be connected with+12V power supply after the pin 1 series resistance R69 of photoelectrical coupler U21, be connected with+5V power supply after the pin 4 series resistance R611 of photoelectrical coupler U21, the pin 3 of photoelectrical coupler U21 is connected with one end of resistance R612 and resistance R613, the other end ground connection of resistance R613, the other end of resistance R612 is connected with the second driver module 14 and Master control chip U0, for output short-circuit signal (SHORT_IN).In addition, pressurizer U20 is used for the voltage stabilizing of+12V power supply to obtain+5V voltage.During work, when short circuit protection module 16 detects short circuit, carry out short-circuit protection.

Please refer to Fig. 3 again, human-computer interaction module 17 comprises RS485 communication unit 171 and LCD display unit 173, RS485 communication unit 171 for realizing the communication between main control module 10 and external equipment, LCD display unit 173 for show sample obtain output voltage values, output current value, inverter the running parameter such as Current Temperatures, output power value, output frequency value.Concrete, RS485 communication unit 171 comprises RS485 interface chip U9, resistance R70, resistance R71 and resistance R72.Concrete, the pin 1 of RS485 interface chip U9 is connected with the pin 1 of Master control chip U0, the pin 2 of RS485 interface chip U9 is connected with the pin 2 of Master control chip U0 with pin 3, the pin 4 of RS485 interface chip U9 is connected with the pin 44 of Master control chip U0, pin 5 ground connection of RS485 interface chip U9, parallel resistance R71 between the pin 6 of RS485 interface chip U9 and pin 7 and be connected respectively to RS485 bus A end (RS485_A) and B hold (RS485_B), parallel resistance R70 between the pin 8 of RS485 interface chip U9 and the pin 6 and pin 8 of RS485 interface chip U9 is connected to+5V power supply, and parallel resistance R72 between the pin 5 of RS485 interface chip U9 and pin 7.Preferably, in the present embodiment, RS485 interface chip U9 model is MAX485.The communication of main control module 10 and external equipment (as equipment such as PCs) can be realized by RS485 communication unit 171.LCD display unit 173 comprises LCD display U10 and resistance R73, wherein the data pin of LCD display U10 is connected with Master control chip U0, pin 1 ground connection of LCD display U10, the pin 2 of LCD display U10 is connected with+5V power supply, ground connection after the pin 3 series resistance R73 of LCD display U10.

As shown in Figure 10, temperature protection module 18 comprises resistance R80, R81, R82, R83, R84, R85, R86, triode Q80, Q81, Q82, field effect transistor Q83, electric capacity C80 and fan FAN1 and FAN2, wherein, one end of resistance R80 is connected with the pin 9 (FAN_OUT) of Master control chip U0, the other end of resistance R80 is connected with the base stage of one end of resistance R81 and triode Q80, the emitter of triode Q80 is connected with one end of resistance R82, the collector electrode of triode Q80 is connected with one end of resistance R83 and resistance R84, the other end of resistance R84 is connected with the base stage of the base stage of triode Q81 and triode Q82, the other end of resistance R83 and the collector electrode of triode Q81, the positive pole of electric capacity C80 and+12V power supply connect, the minus earth of electric capacity C80, the emitter of triode Q81 is connected with one end of the emitter of triode Q82 and resistance R85 and resistance R86, the other end of resistance R85 is connected with the grid of field effect transistor Q83, the drain electrode of field effect transistor Q83 is connected with one end of fan FAN1 and FAN2, the other end of fan FAN1 with FAN2 is connected with+12V power supply, resistance R81, R82, the other end of R86, the collector electrode of triode Q82 and the source ground of field effect transistor Q83.When the temperature of inverter 100 is higher than a certain preset value, Master control chip U0 outputs control signals to temperature protection module 18 and works to control fan FAN1 and FAN2, plays cooling protection effect.

In addition, as shown in figure 11, the digital sinusoidal wave vehicle-mounted inverter 100 of the present invention also comprises power module 19, and power module 19 obtains+5V and+12V power supply for processing low-voltage DC.Power module 19 comprises resistance R90, R91 ... R910, electric capacity C90, C91 ... C914, diode D90, D91 ... D98, field effect transistor Q90, integrated chip U90, pressurizer U91 and U92, each element (is cell voltage in the present embodiment to low-voltage DC, in Figure 10 ,+B represents the positive pole of battery) carry out processing and obtain+12V and+5V voltage, wherein the annexation of each element is see Figure 10, does not describe in detail herein.

Please refer to Figure 12 again, the invention provides a kind of control method of digital sinusoidal wave vehicle-mounted inverter, it is applicable to the digital sinusoidal wave vehicle-mounted inverter shown in Fig. 1 to Figure 11, comprises the following steps:

Step S101, after start, judge low-voltage DC input voltage whether in rated range, if the determination result is YES, perform step S102, otherwise, perform step S107; That is, whether first detect input voltage after start at rated range, if input voltage is in rated range, then can start inverter, on the contrary the guard mode of entering;

Step S102, successively soft start DC/DC boost module and DC/AC inversion module;

Wherein, detect that input voltage is after rated range, first DC/DC boost module soft-start mode is entered, duty ratio by the first pwm signal is slowly increased to preset maximum value by 0, soft start DC/DC boost module avoids in boost process and produces too high transient current, and then avoid too high transient current and cause larger harm to the field effect transistor in DC/DC boost module, improve the stability of DC/DC boost module; After DC/DC boost module soft start completes, soft start DC/AC inversion module, the duty ratio by the second pwm signal is slowly increased to preset maximum value by 0, to make output voltage values slowly rise to load voltage value by 0, thus reduces the impact to load.

Step S103, gathering output current value to judge exporting whether have load, if judged result is for there being load, then performing step S104, otherwise, if judged result is non-loaded, then perform step S105;

Step S104, the duty ratio arranging the first pwm signal is that preset maximum value is to enter load model;

Step S105, under load model, Real-time Collection output voltage values and output current value, and regulate the duty ratio of the first pwm signal and the second pwm signal to adjust output voltage values and output current value in real time according to the PI control method of output voltage values, output current value and default outer voltage and current inner loop;

Wherein, traditional vehicle-mounted inverter does not have current inner loop PI controlling functions, in the present invention, this function can mount high power load (as heavy-duty motor at outlet side, air-conditioning) limit output current, control the climbing of output current, and then the impact reduced field effect transistor, improve safety and stability; In addition, owing to limiting output current, when mounting high power load, not easily the short-circuit protection of trigger inverter or overload protection, improve load capacity accordingly.

Step S106, the duty ratio downgrading the first pwm signal gradually to predetermined minimum (as 3%) to enter idle mode;

Step S107, closes DC/DC boost module to enter protected mode.

More than in conjunction with most preferred embodiment, invention has been described, but the present invention is not limited to the embodiment of above announcement, and should contain various carry out according to essence of the present invention amendment, equivalent combinations.

Claims (10)

1. a digital sinusoidal wave vehicle-mounted inverter, comprise DC/DC boost module, DC/AC inversion module, the first driver module, the second driver module and main control module, it is characterized in that, described DC/DC boost module is used for, by recommending boosting, the low-voltage DC of input is converted to high voltage direct current; It is alternating current that described DC/AC inversion module is used for described high voltage direct current inversion; Described first driver module is connected with described main control module and described DC/DC boost module, for receiving the first pwm signal that described main control module sends and driving described DC/DC boost module according to described first pwm signal; Described second driver module is connected with described main control module and described DC/AC inversion module, for receiving the second pwm signal that described main control module sends and driving described DC/AC inversion module according to described second pwm signal; Whether described main control module accesses load and the duty ratio arranging described first pwm signal when access load being detected is preset maximum value with the duty ratio entering load model and downgrade described first pwm signal when detecting and not accessing load gradually to predetermined minimum to enter idle mode for detecting.

2. digital sinusoidal wave vehicle-mounted inverter as claimed in claim 1, it is characterized in that, described DC/DC boost module comprises boosting unit and rectification unit, described boosting unit is used for changing described low-voltage DC into High Level AC Voltage, it is described high voltage direct current by described high-voltage alternating electric rectification that described rectification unit is used for, and described boosting unit comprise multiple structure identical recommend translation circuit.

3. digital sinusoidal wave vehicle-mounted inverter as claimed in claim 2, is characterized in that, described in recommend translation circuit and comprise first and recommend translation circuit, second recommends translation circuit, 3rd recommends translation circuit and the 4th recommends translation circuit, and wherein said first recommends translation circuit comprises transformer T10, field effect transistor Q11, Q12, Q13, Q14, electric capacity C11 and resistance R10, R11, R12, R13, the grid of R14, described field effect transistor Q11 and Q12 is respectively by described resistance R10, resistance R11 is connected with described first driver module, the drain electrode of described field effect transistor Q11 and Q12 is connected to pin 7 and the pin 8 of described transformer T10 jointly, described field effect transistor Q13 is connected with described first driver module 13 with resistance R13 respectively by described resistance R12 with the grid of Q14, the drain electrode of described field effect transistor Q13 and Q14 is connected to pin 1 and the pin 2 of described transformer T10, described field effect transistor Q11 jointly, Q12, Q13, the source ground of Q14, described electric capacity C11 and described resistance R14 is parallel between the drain electrode of described field effect transistor Q11 and the drain electrode of described field effect transistor Q13 after connecting, the pin 3 of described transformer T10, 4, 5, 6 are electrically connected with described low-voltage direct, and the pin 9 of described transformer T10 is connected with the first input end of pin 10 with described rectification unit, and the pin 12 of described transformer T10 is recommended translation circuit with pin 13 and described second and is connected.

4. digital sinusoidal wave vehicle-mounted inverter as claimed in claim 1, it is characterized in that, described DC/AC inversion module comprises field effect transistor Q20 ~ Q27, inductance L 21, L22, diode D21 ~ D24, electric capacity C21 ~ C26, resistance R20, R21 ~ R224, in parallel and the negative electrode of described diode D21 of described diode D21 and resistance R24 is connected with the signal output part Q1G of described second drive circuit, the anode of described diode D21 is respectively by resistance R20, R23 and described field effect transistor Q20, the grid of Q21 connects, described field effect transistor Q20 is connected with the output of described DC/DC boost module with the drain electrode of Q21, parallel resistance R21 between the grid of described field effect transistor Q20 and source electrode, parallel resistance R22 between the grid of described field effect transistor Q21 and source electrode, described field effect transistor Q20 is connected with the signal output part Q1S of described second drive circuit with the source electrode of Q21, in parallel and the negative electrode of described diode D22 of described diode D22 and resistance R29 is connected with the signal output part Q2G of described second drive circuit, the anode of described diode D22 is respectively by resistance R25, R28 and described field effect transistor Q22, the grid of Q23 connects, described field effect transistor Q22 is connected with the source electrode of described field effect transistor Q20 and Q21 respectively with the drain electrode of Q23, parallel resistance R26 between the grid of described field effect transistor Q22 and source electrode, parallel resistance R27 between the grid of described field effect transistor Q23 and source electrode, the source electrode of described field effect transistor Q22 is connected with the source electrode of field effect transistor Q23, described electric capacity C21 is parallel between the drain electrode of described field effect transistor Q20 and the source electrode of field effect transistor Q22, in parallel and the negative electrode of described diode D23 of described diode D23 and resistance R215 is connected with the signal output part Q3G of the second drive circuit, the anode of described diode D23 is respectively by resistance R211, R214 and described field effect transistor Q24, the grid of Q25 connects, described field effect transistor Q24 is connected with the output of described DC/DC boost module with the drain electrode of Q25, parallel resistance R210 between the grid of described field effect transistor Q24 and source electrode, parallel resistance R213 between the grid of described field effect transistor Q25 and source electrode, and the source electrode of described field effect transistor Q24 and the source electrode of field effect transistor Q25 are connected with the signal output part Q3S of described second drive circuit, described electric capacity C22 is parallel between the source electrode of described field effect transistor Q22 and the drain electrode of described field effect transistor Q24, in parallel and the negative electrode of described diode D24 of described diode D24 and resistance R220 is connected with the signal output part Q4G of described second drive circuit, the anode of described diode D24 is respectively by resistance R217, R219 and described field effect transistor Q26, the grid of Q27 connects, described field effect transistor Q26 is connected with the source electrode of described field effect transistor Q24 and Q25 respectively with the drain electrode of Q27, parallel resistance R216 between the grid of described field effect transistor Q26 and source electrode, parallel resistance R218 between the grid of described field effect transistor Q27 and source electrode, the source electrode of described field effect transistor Q26 is connected with the source electrode of field effect transistor Q27, described resistance R221, resistance R222, one end ground connection after resistance R223 and resistance R224 parallel connection, the other end is connected with the source electrode of described field effect transistor Q26, one end of described inductance L 21 is connected with the signal output part Q1S of described second driver module, the other end of described inductance L 21 is connected with one end of described electric capacity C23 and the pin 3 of described inductance L 22, the other end of described electric capacity C23 is connected with the signal output part Q3S of the pin 4 of described inductance L 22 and described second driver module, described electric capacity C24 in parallel between the pin 1 of described inductance L 22 and pin 2, described electric capacity C25 and electric capacity C26 is parallel to the two ends of described electric capacity C24 after connecting, and the voltage at described electric capacity 24 two ends is respectively live wire and the zero line of the described alternating current that inversion obtains.

5. digital sinusoidal wave vehicle-mounted inverter as claimed in claim 1, is characterized in that, also comprise:

Sampling module, described sampling module is for gathering output voltage values and the output current value of described alternating current;

Human-computer interaction module, described human-computer interaction module be used for described main control module with communicate between external equipment and show the running parameter of described digital sinusoidal wave vehicle-mounted inverter; And

Short circuit protection module, described short circuit protection module is connected with described DC/AC inversion module, described second driver module and described main control module, for carrying out short-circuit protection.

6. digital sinusoidal wave vehicle-mounted inverter as claimed in claim 5, it is characterized in that, described sampling module comprises voltage isolation sampling unit and electric current isolation sampling unit, described voltage isolation sampling unit comprises voltage transformer T1, operational amplifier U5, diode D50, D51, D52, electric capacity C50 and resistance R50, R51 ~ R510, described resistance R50 with R51 connects and one end after series connection is connected with the pin 4 of described voltage transformer T1, the other end is connected with the zero line of described alternating current, described resistance R52 with R53 connects and one end after series connection is connected with the pin 3 of described voltage transformer T1, the other end is connected with the live wire of described alternating current, described resistance R54, between the pin 1 that diode D50 and electric capacity C50 is parallel to described voltage transformer T1 and pin 2, described resistance R55 is series between the pin 1 of voltage transformer T1 and the pin 3 of described operational amplifier U5, described resistance R56 is connected between the pin 2 of operational amplifier U5 and pin 1, the pin 1 of described operational amplifier U5 simultaneously with described resistance R57, one end of R58 and the pin 10 of described operational amplifier U5 connect, the other end ground connection of described resistance R57, the other end of described resistance R58 is connected with one end of the pin 6 of described operational amplifier U5 and described resistance R59, the pin 7 of described operational amplifier U5 is connected with the anode of described diode D51, the negative electrode of described diode D51 be connected with the other end of described resistance R59 and coating-forming voltage feedback end to feed back described output voltage values to described main control module, the pin 9 of described operational amplifier U5 is connected with described pressure feedback port, and the pin 8 of described operational amplifier U5 is connected with the anode of diode D52, the negative electrode of described diode D52 is connected with one end of described pressure feedback port and described resistance R510, the other end ground connection of described resistance R510.

7. digital sinusoidal wave vehicle-mounted inverter as claimed in claim 1, it is characterized in that, described first driver module and described second driver module are optical couple isolation drive circuit, described first pwm signal comprises pwm signal PWM1 and PWM2, described first driver module comprises optocoupler driving chip U7, U8 and resistance R30, R31, R32, R33, the pin 2 of described optocoupler driving chip U7 is connected with one end of described resistance R31, the other end of described resistance R31 is connected to receive the pwm signal PWM1 that described main control module exports with described main control module, described resistance R30 is parallel between the other end of described resistance R31 and the pin 4 of described optocoupler driving chip U7, the pin 6 of described optocoupler driving chip U7 and pin 7 link together and drive singal PWM1_0 after output processing to described DC/DC boost module, the pin 2 of described optocoupler driving chip U8 is connected with one end of described resistance R33, the other end of described resistance R33 is connected to receive the pwm signal PWM2 that described main control module exports with described main control module, described resistance R32 is parallel between the other end of described resistance R33 and the pin 4 of described optocoupler driving chip U8, the pin 6 of described optocoupler driving chip U8 and pin 7 link together and drive singal PWM2_0 after output processing to described DC/DC boost module.

8. a control method for digital sinusoidal wave vehicle-mounted inverter, is applicable to the digital sinusoidal wave vehicle-mounted inverter described in any one of claim 1 to 7, it is characterized in that, comprise the following steps:

Gather output current value to judge exporting whether have load;

If judged result is for there being load, then the duty ratio that the first pwm signal is set be preset maximum value to enter load model, if judged result is non-loaded, then the duty ratio downgrading described first pwm signal gradually to predetermined minimum to enter idle mode.

9. control method as claimed in claim 8, is characterized in that, described collection output current value is to judge output also comprises before whether having load:

Judge low-voltage DC input voltage whether in rated range;

If the determination result is YES, then soft start DC/DC boost module and DC/AC inversion mould successively, if judged result is no, then closes described DC/DC boost module to enter protected mode.

10. control method as claimed in claim 9, it is characterized in that, the described duty ratio arranging described first pwm signal is that preset maximum value also comprises after entering load model:

Real-time Collection output voltage values and described output current value;

Regulate the duty ratio of described first pwm signal and the second pwm signal to adjust described output voltage values and described output current value in real time according to the PI control method of described output voltage values, described output current value and default outer voltage and current inner loop.