Detection system of inverter in aging experiment

Abstract

The invention discloses a detection system for an inverter in an aging experiment, and relates to the technical field of electronics and electrics. The system comprises an inverter circuit, a pulse drive and protection circuit, a voltage protection circuit, a temperature protection circuit, an open-phase protection circuit, a 15V power supply protection circuit, a communication protection circuit, a rectification circuit, an inverter test controller and upper computer software. The six protection circuits are respectively connected with the MCU of the inverter; the inverter test controller in the system is connected with the MCU of the inverter through an optical fiber and is connected with the upper computer software through a serial port; the system comprises a rectifying circuit which is respectively connected with a 380V alternating current power supply and an MCU (Microprogrammed Control Unit) of an inverter through circuits; according to the technology, all parameters of the inverter are monitored in real time in the long-time aging experiment through upper computer software and displayed in real time, manual intervention is not needed in the technology, the labor cost is saved, and the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the field of electronic and electrical technology, in particular to a detection system for an inverter in an aging experiment. Background Art

[0002] As inverters are increasingly used in industrial systems, the demand for inverter equipment has also increased dramatically. Product testing issues have received more and more attention during the mass production of equipment. However, some product tests on the production line are still performed manually, which brings a lot of uncertainty to production management and product quality. Over-reliance on manual operation in aging experiments will lead to low production efficiency, complicated processes, and easy errors.

[0003] The invention patent with patent number CN108572286A discloses a "power inverter detection device and method thereof", which records a method for detecting the working conditions of the power inverter at different temperatures by observing the lighting conditions of the display lights connected to the inverter. However, this invention patent still has the problem that the main work depends on manual labor, and there will be the disadvantage of easy errors in the judgment process; the invention patent with patent number CN112526264A discloses "a single-phase inverter detection system", which records a one-button automatic test of related detection items, realizes routine functional tests on single-phase inverters in trains, detects technical parameters such as input overvoltage, input undervoltage, output overcurrent, output short circuit, switch quantity detection, overall efficiency, etc., and realizes timely feedback of faults. However, this technology still has the problem that subsequent processing requires manual judgment, and the process is cumbersome; therefore, it is urgent to propose a technical method that can intuitively display inverter detection data, does not require manual intervention, and automatically handles emergency when the main line of the detection equipment fails. Summary of the invention

[0004] The purpose of the present invention is to provide a detection system for an inverter in an aging experiment to solve the problems raised in the prior art.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a detection system for an inverter in an aging experiment, the system comprising an inverter circuit, a pulse drive and protection circuit, a voltage protection circuit, a temperature protection circuit, a phase loss protection circuit, a 15V power supply protection circuit, a communication protection circuit, a rectifier circuit, an inverter test controller and a host computer software; the inverter circuit comprises four IGBT chips, namely IGBT1, IGBT2, IGBT3 and IGBT4; the pulse drive and protection circuit is connected to the gates of the four IGBT chips in the inverter circuit; the inverter In the circuit, chips IGBT1 and IGBT2 are connected in series, chips IGBT3 and IGBT4 are connected in series, the two series circuits are connected in parallel, and both ends of the parallel circuit are connected to the rectifier circuit, one end of the capacitor CD is connected to the emitter of IGBT2 and IGBT4 and then connected to the rectifier circuit, and the other end is connected to the collector of IGBT1 and IGBT3 and then connected to the rectifier circuit; the inverter test controller in the system is connected to the MCU of the inverter through optical fiber, and is connected to the upper computer software through the serial port; the rectifier circuit in the system is connected to the 380V AC power supply and the MCU of the inverter respectively;

[0006] The pulse drive and protection circuit monitors faults in the circuit by monitoring the hardware cold soldering problems of any bridge arm in the inverter circuit; the voltage protection circuit determines whether there is a voltage fault by monitoring overvoltage and undervoltage problems; the temperature protection circuit detects whether a fault occurs by comparing the voltage value corresponding to the bridge arm temperature obtained by comparing the external thermistor; the missing item protection circuit determines whether a missing item occurs in the circuit through the pin signal on the MCU; the 15V power supply protection circuit determines whether the 15V power supply fails by detecting the pin signal connected to the MCU; the communication protection circuit determines whether a communication fault occurs by detecting the amount of information received by the inverter controller and the frequency change of the received information.

[0007] Furthermore, the pulse drive and protection circuit can detect the cold soldering problem of any bridge arm in the inverter circuit in hardware. After the cold soldering problem is found, an early warning is issued to the MCU to lock the inverter process; IGBT1, IGBT2, IGBT3 and IGBT4 chips constitute the bridge arm in the inverter circuit, wherein IGBT1 and IGBT2 constitute the left bridge arm, and IGBT3 and IGBT4 constitute the right bridge arm; in the circuit of the pulse drive and protection circuit, chip 2SC0108T2 is the IGBT driver chip, driving the conduction and shutdown of the two IGBT tubes of the left bridge arm. When a fault occurs, the driver chip detects the fault and outputs a low-level signal at the Sox pin to protect the locking system. In normal state, the Sox pin outputs a high-level signal; the MCU determines whether the driver chip is cold soldered or a fault occurs by detecting the level signal output by the Sox pin; the MCU controls the driver chip by controlling the INL and INR pins through a pulse sequence, thereby driving the conduction and shutdown of the left and right bridge arm tubes;

[0008] The pulse drive and protection circuit includes an IGBT drive chip U8, connectors J2 and J3, and the circuit includes capacitor C52, resistors R32, R39, R40, R41, diodes D12, D13, resistor R36, capacitor C58, resistors R64, R54, R66, R68, R60, capacitors C56, C59, C57, resistors R46, R53, R55; trigger chip U9, transistor U10, capacitor C53, resistors R45, R52, R59, R63; the protection circuit includes an IGBT drive chip U12, connectors J4 and J5 The circuit includes capacitor C63, resistors R75, R84, R85, R87, diodes D14, D15, resistor R76, capacitor C70, resistors R97, R108, R110, R112, R118, capacitors C67, C68, C72, resistors R93, R96, R99; connector U13, capacitor C69, transistor U14, resistors R107, R120, R122; level converter U11, capacitors C62, C66, C71, C73, resistors R83, R95, R98, R105, R119, R121;

[0009] Pin 1 of IGBT driver chip U8 is grounded; Pin 2 is connected to input signal INL; Pin 3 is connected to input signal DEN; Pins 4 and 5 are connected to 15V power supply, 15V power supply is connected to one end of capacitor C56, and the other end of capacitor C56 is grounded, one end of resistor R46 is grounded, and the other end is connected to pin 5; Pin 6 and Pin 7 are connected in parallel to form pin SOL and connected to capacitor C59, Pin 8 is connected to the parallel circuit of resistor R53 and capacitor C57; Pin 9 is connected to the cathode of diode D13; Pin 10 is connected to capacitor C58; Pin 11 is connected to the parallel circuit composed of resistors R65 and R66. The pin 12 is connected to the resistor R64; the pin 13 is connected to the resistor R54; the pin 17 is connected to the cathode of the diode D12, the pin 18 is connected to the capacitor C52, the pin 19 is connected to R40, the pin 20 is connected to the resistor R39, and the pin 21 is connected to the resistor R32; the pin B1 of the connector J2 in the circuit is connected to one end of the capacitor C52, the pin B2 is connected to R40 and the resistor R41; the pin B4 is connected to the resistor R36; the pin B1 of the connector J3 in the circuit is connected to one end of the capacitor C58, the pin B2 is connected to the resistor R66 and the resistor R68; the pin B4 is connected to the resistor R60;

[0010] Pin 1 of the trigger chip U9 is connected to pin 12 of the level converter, pin 2 is connected to pin 3, pin 4 is connected to resistor R45, and the other end of resistor R45 is connected to pin 3 of chip U8 as a signal output terminal DEN, pin 5 is connected to pin 9, pin 6 is connected to pin 8, pin 7 is grounded, pin 8 is connected to resistor R59, the other end of resistor R59 is connected to one end of resistor R63, and is connected to the base of transistor U10, the collector of transistor U10 is connected to one end of resistor R52, the emitter is grounded, and the other end of resistor R52 is connected to a 15V power supply; pin 9 serves as a signal pin SOL, pin 10 serves as a signal output terminal connected to pin 2 of chip U8, pin 11 is connected to pin 12, pin 13 serves as a signal output terminal connected to pin 6 of the level converter, pin 14 is connected to a 15V power supply, and is connected to a grounded capacitor C53;

[0011] Pin 1 of the IGBT driver chip U12 is grounded, pin 2 is connected to the INR input signal, pin 3 is connected to the DEN input signal, pins 4 and 5 are connected to a 15V power supply, the 15V power supply is connected to one end of the capacitor C67, and the other end of the capacitor C67 is grounded, one end of the resistor R93 is connected to pin 5, and the other end is grounded, pins 6 and 7 are connected in parallel to form pin SOR and are connected to one end of the capacitor C72, pin 8 is connected to the parallel circuit of resistor R96 and capacitor C68, pin 9 is connected to the cathode of the diode D15, pin 10 is connected to one end of the capacitor C63, pin 11 is connected to the parallel circuit of resistor R109 and resistor R110, and pin 12 connected to resistor R108, pin 13 is connected to resistor R97, pin 17 is connected to the cathode of diode D14, pin 18 is connected to capacitor C63, pin 19 is connected to the parallel circuit of resistor R85 and resistor R86, pin 20 is connected to resistor R84, and pin 21 is connected to resistor R75; pin B1 of connector J4 in the circuit is connected to one end of capacitor C63, pin B2 is connected to resistor R85 and resistor R87; pin B4 is connected to resistor R76; pin B1 of connector J5 in the circuit is connected to one end of capacitor C70, pin B2 is connected to resistor R110 and resistor R112; pin B4 is connected to resistor R118;

[0012] Pin 5 of the trigger chip U13 is connected to pin 9, pin 6 is connected to pin 8, pin 7 is grounded, pin 8 is connected to resistor R107, the other end of resistor R107 is connected to one end of resistor R122, and is connected to the base of transistor U14, the collector of transistor U14 is connected to resistor R120, the emitter is grounded, and the other end of resistor R120 is connected to a 15V power supply; pin 9 serves as a signal pin SOR, pin 10 serves as a signal output end and is connected to pin 2 of chip U12, pin 11 is connected to pin 12, pin 13 serves as a signal output end and is connected to pin 2 of the level converter, pin 14 is connected to a 15V power supply, and is connected to a grounded capacitor C69;

[0013] Pin 1 of the level converter U11 is connected to the 5V power supply, pin 2 is connected to pin 13 of the trigger U13, pin 3 is connected to one end of the resistor R98, pin 5 is grounded, pin 6 is connected to pin 13 of the trigger U9DE, pin 7 is connected to the resistor R119, pin 8 is grounded, pin 9 is grounded, pin 11 is connected to capacitor C66, pin 12 is used as a signal output pin (-GEN), pin 13 is connected to the 5V power supply, pin 14 is grounded, pin 16 is connected to the 15V power supply, one end of the capacitor C62 is grounded, one end is connected to the 15V power supply, and resistor One end of R83 is connected to capacitor C66, and the other end is connected to resistor R95 and this section serves as output pin SD, and the other end of resistor R95 is grounded; resistor R98, resistor 105 and capacitor C71 form a series circuit, and the connection between resistor R105 and capacitor C66 is grounded, and the connection between resistor R98 and resistor R105 serves as output pin IGBTR; resistor R119, resistor 121 and capacitor C73 form a series circuit, and the connection between resistor R121 and capacitor C73 is grounded, and the connection between resistor R119 and resistor R121 serves as output pin IGBTL.

[0014] Furthermore, the voltage protection circuit includes two parts: overvoltage protection and undervoltage protection; the voltage protection circuit divides the voltage through a sampling resistor, and after the voltage division, a comparison signal is output to the MCU pin through a reference voltage comparator, and the MCU detects the occurrence of a fault by judging the high and low levels on the pin and then performs voltage protection; when overvoltage protection occurs, the MCU detects that the signal on the pin (-VDOV) is a high-level signal, and when it returns to normal, it detects that the signal on the pin (-VDOV) is a low-level signal; when undervoltage protection occurs, the MCU detects that the signal on the pin (-VDUV) is a low-level signal, and when it returns to normal, it detects that the signal on the pin (-VDUV) is a high-level signal;

[0015] The voltage protection circuit includes a photocoupler U23, resistors R167, R168, R169, R170, R171, R172, R173, R157, capacitors C90, C88, C92, C87, C93, C94, C89, C91, and operational amplifiers U24A, U25A, and U43B; pin 1 of the photocoupler U23 is connected to one end of R173, pin 2 is connected to a 5V power supply, pin 3 is connected to capacitor C88, pin 4 is grounded, pin 5 is grounded and connected to the same-phase input terminal of the operational amplifier U25A, and pin 6 is connected to the reverse input terminal of the operational amplifier U25A; one end of the resistor R167 is connected to the reverse input terminal of the operational amplifier U24A, and the other end is connected to capacitor C90, and the other end of capacitor C90 is grounded; the 5V power supply is connected, and the other end is grounded; one end of the resistor R173 is connected to the The output end is connected, and the other end is connected to pin 1 of U23; capacitor C93 and capacitor C94 are connected in parallel, and one end of the parallel circuit is grounded and the other end is connected to a 5V power supply; resistor R168 and resistor R169 are connected in series and then connected in parallel with capacitor C87, and one end of this circuit is connected to the reverse input end of U25A and one end is connected to the output end; one end of resistor R170 is connected to the output end of U25A, and the other end is connected to one end of capacitor C89 and connected to the positive input end of U43B, and the other end of capacitor C89 is grounded; one end of resistor R157 is connected to a 5V power supply, and the other end is connected to the output end of U43B; resistor R172 and capacitor C91 are connected in parallel, and one end of this parallel circuit is grounded and the other end is connected to the reverse input end of U43B; one end of resistor R171 is connected to the reverse input end of U43B; the output end of U43B is connected to pin (-VDUV);

[0016] The voltage protection circuit also includes a voltage reference source chip U18, capacitors C82, C81, C84, C83, C86, resistors R143, R145, R137, R138, R139, R140, R142, a diode D25, and operational amplifiers U20 and U43A; pin 1 of the voltage reference source chip U18 is connected to one end of the capacitor C82, pin 2 is connected to the capacitor C81, and pin 3 is grounded; one end of the capacitor C82 is connected to a 15V power supply, and the other end is grounded; one end of the resistor R138 is connected to a 5V power supply, and the other end is connected to the output end of the operational amplifier; resistor R137 is connected in series with D25, one end of R137 is connected to the positive input end of U20, and the other end is connected to the negative terminal of the diode D25, and the positive pole of D25 is connected to the output end of U20; One end of capacitor C83 is connected to the 5VA power supply, and the other end is grounded; one end of resistor R139 is connected to pin UD1, and the other end is connected to the positive input terminal of U20; one end of resistor R140 is connected to pin REF, and the other end is connected to the reverse input terminal of U20; resistor R142 and capacitor C86 are connected in parallel, and one end of this parallel circuit is grounded, and the other end is connected to the reverse input terminal of U20; pin UD1 is connected to the positive input terminal of U43A; one end of resistor R143 is connected to pin REF, and the other end is connected to the reverse input terminal of U43A; one end of resistor R145 is grounded, and the other end is connected to the reverse input terminal of U43A; one end of capacitor C84 is grounded, and the other end is connected to the 5V power supply and connected to the power input terminal of U43A; the output terminal of U43A is connected to pin (-VDOV).

[0017] Furthermore, the temperature protection circuit obtains the voltage value corresponding to the temperature of the left bridge arm through the thermistor externally connected to J8, and then outputs a comparison signal to the MCU pin through the comparator. The MCU detects the occurrence of a fault by judging the high and low levels on the pin and then performs temperature protection. When temperature protection occurs, the MCU detects that the signal on the pin (-KLH) is a low-level signal. When it returns to normal, it detects that the signal on the pin (-KLH) is a high-level signal.

[0018] The temperature protection circuit obtains the voltage value corresponding to the temperature of the right bridge arm through the thermistor connected to J9, and also outputs the comparison signal to the MCU pin through the comparator. The MCU detects the occurrence of a fault by judging the high and low levels on the pin and then performs temperature protection. When temperature protection occurs, the MCU detects that the signal on the pin (-KRH) is a low-level signal. When it returns to normal, it detects that the signal on the pin (-KRH) is a high-level signal.

[0019] The temperature protection circuit includes two connectors J8 and J9, two operational amplifiers U44B and U44A, transistors U31 and U33, optocouplers U32 and U34, resistors R176, R177, R178, R179, R180, R181, R182, R184, R185, R186, R187, R188, R189 and R190, and capacitors C102, C103, C104, C105 and C106;

[0020] Connector J8 pin 1 is externally connected, pin 2 is externally connected, pin 3 is connected to the 5V_T power supply, pin 4 is connected to one end of resistor R179 and connected to the reverse input pin 6 of U44B, the other end of resistor R179 is grounded, capacitor C102 is connected in parallel with resistor R179, one end of resistor R181 is connected to the 5V_T power supply, and the other end is connected to the positive input pin 5 of U44B, resistor R182 and capacitor C103 are connected in parallel, and one end of this parallel circuit is grounded, and the other end is connected to the positive input pin 5 of U44B, one end of resistor R176 is connected to the 5V_T power supply, and the other end is connected to the transistor The collector of U3_ is connected, one end of the resistor R177 is connected to the 5V_T power supply, and the other end is connected to the base of U31; Pin 1 of the optocoupler U32 is connected to the emitter of the transistor, Pin 2 is grounded, Pin 3 is grounded, and Pin 4 is connected to the resistor R178; One end of the resistor R180 is connected to the emitter of the transistor U31, and the other end is grounded; One end of the resistor R178 is connected to the 5V power supply, and the other end is connected to Pin 4 of the optocoupler, and the pin (-KLH) is connected between the resistor R178 and Pin 4 of the optocoupler; The capacitor C102 is connected to the reverse input pin 6 of U44B, and the pin VTL is connected between the two;

[0021] Connector J9 pin 1 is externally connected, pin 2 is externally connected, pin 3 is connected to the 5V_T power supply, pin 4 is connected to one end of resistor R187 and connected to the reverse input terminal of U44A, the other end of resistor R87 is grounded, capacitor C105 is connected in parallel with resistor R187, one end of resistor R188 is connected to the 5V_T power supply, and the other end is connected to pin 3 of the positive input terminal of U44A, resistor R190 and capacitor C106 are connected in parallel, and one end of this parallel circuit is grounded and connected to power supply pin 4 of U44A, and the other end is connected to pin 3 of the positive input terminal of U44A, one end of resistor R184 is connected to the 5V_T power supply, and the other end is connected to the collector of transistor U33, resistor R1 One end of 85 is connected to the 5V_T power supply, and the other end is connected to the base of U33; pin 1 of optocoupler U34 is connected to the emitter of transistor U33, pin 2 is grounded, pin 3 is grounded, and pin 4 is connected to resistor R186; one end of resistor R189 is connected to the emitter of transistor U33, and the other end is grounded; one end of capacitor C104 is grounded, and the other end is connected to the 5V power supply, and is connected to power pin 8 of U44A; one end of resistor R186 is connected to the 5V power supply, and the other end is connected to pin 4 of the optocoupler, and pin (-KRH) is connected between resistor R186 and pin 4 of the optocoupler; capacitor C105 is connected to the reverse input end of U44A, and pin VTR is connected between the two.

[0022] Furthermore, the phase loss protection circuit is that after any phase of the three phases U, V, and W is missing, the MCU determines whether the phase loss occurs by detecting the pin signal connected to the MCU. When a phase loss fault occurs, the MCU detects a pulse signal on the pin (-Vlost). When it returns to normal, the MCU detects a low-level signal on the pin (-Vlost);

[0023] The phase loss protection circuit includes pins J10, J11, and J12, resistors R202, R206, R207, R208, R213, R219, R224, R234, and R235, diodes D26, D27, D28, D29, D30, D31, D32, D33, and D34, transistor U41, optocoupler U40, and capacitors C111 and C112;

[0024] Pin 1 and pin 2 of pin header J10 are connected to one end of resistor R202, and the other end of resistor R202 is connected between diode D28 and diode D29; pin 1 and pin 2 of pin header J11 are connected to one end of resistor R208, and the other end of resistor R208 is connected between diode D27 and diode D31; pin 1 and pin 2 of pin header J12 are connected to one end of resistor R224, and the other end of resistor R224 is connected to diode D27 and diode D31. The anode of diode D32 is connected to resistor R234, the cathode is connected to the anode of diode D26, the cathode of D26 is connected to one end of resistor R207, the anode of diode D31 is connected to one end of resistor R234, the cathode of diode D27 is connected to the anode of diode D27, the cathode of D27 is connected to one end of resistor R207, the anode of diode D33 is connected to one end of resistor R234, the cathode of diode D33 is connected to the anode of diode D28, the cathode of diode D28 is connected to one end of resistor R207. The positive electrode of the diode D29 is connected to one end of the resistor R234, and the negative electrode is connected to one end of the resistor R207. One end of the resistor R219 is connected to the collector of the transistor U41, and the other end is connected to the base of U41. The positive electrode of the diode D30 is connected to the base of the transistor, and the negative electrode is connected to the negative electrode of the diode. The positive electrode of D34 is connected to one end of the resistor R234. One end of R234 is connected to R235. The other end of the resistor R235 is connected to the emitter of the transistor. The pin 1 of the optocoupler U40 is connected to one end of the resistor R207, the pin 2 is connected to the emitter of the transistor, the pin 3 is grounded, the pin 4 is connected to one end of the resistor R206, the other end of R206 is connected to a 5V power supply, one end of the capacitor C111 is connected to the 5V power supply, and the other end is grounded, one end of the capacitor C112 is grounded, and the other end is connected to the pin (-Vlost), one end of the resistor R213 is connected to the pin 4 of the optocoupler U40, and the other end is connected to the output pin (-Vlost).

[0025] Furthermore, the 15V power supply protection circuit is used to detect whether the 15V power supply in the circuit fails; the 15V power supply input circuit includes two 15V power supplies, and when one power supply fails, it will automatically switch to the other power supply for power supply; the MCU determines whether the fault occurs by detecting the pin signal connected to the MCU. When a fault occurs, the MCU detects that the pin (-15Vtest) is a low-level signal, and when it returns to normal, the MCU detects that the pin (-15Vtest) is a high-level signal;

[0026] The 15V power supply protection circuit includes a spring-type PCB terminal J1, resistors R2, R3, R4, R5, diodes D1 and D5, blue light-emitting diodes D7 and D8, a voltage-stabilizing diode D6, and an optocoupler OP1; pin A1 of J1 is connected to the cathode of D5, pin A2 is connected to the power supply 15V1, pin A3 is connected to the cathode of diode D5, pin A4 is connected to the 15V power supply, pins B1, B2, B3, and B4 are externally connected, the anode of diode D5 is grounded, the anode of diode D1 is connected to 15V1, and the cathode is connected to 15V1. The pin 1 of the optocoupler OP1 is connected to one end of the resistor R2, the other end of R2 is connected to the 15V power supply, the pin 2 is connected to the negative pole of D6, the pin 3 is connected to the positive pole of D6 and grounded, the pin 4 is connected to the resistor R3, the other end of R3 is connected to the 5V power supply, the negative pole of the blue light-emitting diode D7 is grounded, the positive pole is connected to R4, the other end of R4 is connected to the power supply 15V1, the negative pole of D8 is grounded, the positive pole is connected to one end of the resistor R5, and the other end of R5 is connected to the 15V power supply; the pin (-15Vtest) is connected to the pin 4 of the optocoupler.

[0027] Furthermore, the communication protection circuit determines whether a communication failure occurs by the frequency of information reported by the inverter to the inverter tester; if the inverter does not report the switching quantity and analog quantity information to the inverter test controller within the time Δt, it is determined that the communication between the two has failed, that is, it is determined that a communication failure has occurred, and the MCU locks the inverter process to perform communication protection.

[0028] Furthermore, the inverter test controller generates a PWM waveform and sends the PWM signal to the inverter's MCU through optical fiber to drive the on and off of the IGBT tube. On the other hand, the inverter test controller sends the received fault signal and analog signal to the host computer software through the serial port.

[0029] Furthermore, the host computer software displays the data information reported by the inverter test controller and the start of the inverter process in real time.

[0030] Furthermore, the rectifier circuit is used to rectify the 380V AC signal into a DC signal and then supply power to the MCU and charge the CD capacitor; the rectifier circuit includes two fuses and six diodes VT1, VT2, VT3, VT4, VT5, and VT6. The positive electrode of diode VT1 is connected to the negative electrode of VT4, and the two are connected in series. The positive electrode of VT3 is connected to the negative electrode of VT6, and the two are connected in series. The positive electrode of VT5 is connected to the negative electrode of VT2, and the two are connected in series. The three series circuits are connected in parallel to form a rectifier circuit.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The purpose of the present invention is to monitor various parameters of the inverter in real time during a long-term aging experiment of the inverter and display them in real time, thereby saving labor costs, improving production efficiency, and eliminating the need for manual intervention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 An inverter test block diagram of a detection system for an inverter in an aging experiment of the present invention;

[0034] Figure 2 A circuit diagram of a pulse drive and protection circuit of a detection system of an inverter in an aging experiment of the present invention;

[0035] Figure 3 A circuit diagram of a voltage protection circuit of a detection system of an inverter in an aging experiment of the present invention;

[0036] Figure 4 A circuit diagram of a temperature protection circuit of a detection system of an inverter in an aging experiment of the present invention;

[0037] Figure 5 A circuit diagram of a phase-loss protection circuit of a detection system of an inverter in an aging experiment of the present invention;

[0038] Figure 6 A circuit diagram of a 15V power supply protection circuit of a detection system for an inverter in an aging experiment of the present invention;

[0039] Figure 7 The present invention is a circuit diagram of a rectifier circuit of a detection system for an inverter in an aging experiment. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0041] like Figure 1-Figure 7As shown, the present invention provides a technical solution, a detection system for an inverter in an aging experiment, the system includes an inverter circuit, a pulse drive and protection circuit, a voltage protection circuit, a temperature protection circuit, a phase loss protection circuit, a 15V power supply protection circuit, a communication protection circuit, a rectifier circuit, an inverter test controller and a host computer software; the inverter circuit includes four IGBT chips, namely IGBT1, IGBT2, IGBT3 and IGBT4; the pulse drive and protection circuit is connected to the gates of the four IGBT chips in the inverter circuit; the inverter circuit Chips IGBT1 and IGBT2 are connected in series, chips IGBT3 and IGBT4 are connected in series, the two series circuits are connected in parallel, and both ends of the parallel circuit are connected to the rectifier circuit, one end of the capacitor CD is connected to the emitters of IGBT2 and IGBT4 and then connected to the rectifier circuit, and the other end is connected to the collectors of IGBT1 and IGBT3 and then connected to the rectifier circuit; the inverter test controller in the system is connected to the MCU of the inverter through optical fiber, and is connected to the upper computer software through the serial port; the rectifier circuit in the system is connected to the 380V AC power supply and the MCU of the inverter respectively;

[0042] The pulse drive and protection circuit monitors faults in the circuit by monitoring the hardware cold soldering problems of any bridge arm in the inverter circuit; the voltage protection circuit determines whether there is a voltage fault by monitoring overvoltage and undervoltage problems; the temperature protection circuit detects whether a fault occurs by comparing the voltage value corresponding to the bridge arm temperature obtained by comparing the external thermistor; the missing item protection circuit determines whether a missing item occurs in the circuit through the pin signal on the MCU; the 15V power supply protection circuit determines whether the 15V power supply fails by detecting the pin signal connected to the MCU; the communication protection circuit determines whether a communication fault occurs by detecting the amount of information received by the inverter controller and the frequency change of the received information.

[0043] The pulse drive and protection circuit can detect the cold soldering problem of any bridge arm in the inverter circuit in hardware. After the cold soldering problem is found, an early warning is issued to the MCU to lock the inverter process; IGBT1, IGBT2, IGBT3 and IGBT4 chips constitute the bridge arm in the inverter circuit, wherein IGBT1 and IGBT2 constitute the left bridge arm, and IGBT3 and IGBT4 constitute the right bridge arm; in the circuit of the pulse drive and protection circuit, chip 2SC0108T2 is the IGBT driver chip, driving the conduction and shutdown of the two IGBT tubes of the left bridge arm. When a fault occurs, the driver chip detects the fault and outputs a low-level signal at the Sox pin to protect the locking system. In normal state, the Sox pin outputs a high-level signal; the MCU determines whether the driver chip is cold soldered or a fault occurs by detecting the level signal output by the Sox pin; the MCU controls the driver chip by controlling the INL and INR pins through a pulse sequence, thereby driving the conduction and shutdown of the left and right bridge arm tubes.

[0044] The voltage protection circuit includes two parts: overvoltage protection and undervoltage protection. The voltage protection circuit divides the voltage through a sampling resistor, and after the voltage division, a comparison signal is output to the MCU pin through a reference voltage comparator. The MCU detects the occurrence of a fault by judging the high and low levels on the pin and then performs voltage protection. When overvoltage protection occurs, the MCU detects that the signal on the pin (-VDOV) is a high-level signal. When it returns to normal, it detects that the signal on the pin (-VDOV) is a low-level signal. When undervoltage protection occurs, the MCU detects that the signal on the pin (-VDUV) is a low-level signal. When it returns to normal, it detects that the signal on the pin (-VDUV) is a high-level signal.

[0045] The temperature protection circuit obtains the voltage value corresponding to the temperature of the left bridge arm through the thermistor externally connected to J8, and then outputs a comparison signal to the MCU pin through the comparator. The MCU detects the occurrence of a fault by judging the high and low levels on the pin and then performs temperature protection. When temperature protection occurs, the MCU detects that the signal on the pin (-KLH) is a low-level signal. When it returns to normal, it detects that the signal on the pin (-KLH) is a high-level signal.

[0046] The temperature protection circuit obtains the voltage value corresponding to the right bridge arm temperature through the thermistor connected to J9, and also outputs the comparison signal to the MCU pin through the comparator. The MCU detects the occurrence of a fault by judging the high and low levels on the pin and then performs temperature protection. When temperature protection occurs, the MCU detects that the signal on the pin (-KRH) is a low-level signal. When it returns to normal, it detects that the signal on the pin (-KRH) is a high-level signal.

[0047] The phase loss protection circuit is that when any phase of U, V, and W is missing, the MCU determines whether a phase loss occurs by detecting the pin signal connected to the MCU. When a phase loss fault occurs, the MCU detects a pulse signal on the pin (-Vlost). When it returns to normal, the MCU detects a low-level signal on the pin (-Vlost).

[0048] The 15V power supply protection circuit is used to detect whether the 15V power supply in the circuit fails; the 15V power supply input circuit includes two 15V power supplies. When one power supply fails, it will automatically switch to the other power supply for power supply; the MCU determines whether a fault occurs by detecting the pin signal connected to the MCU. When a fault occurs, the MCU detects a low-level signal on the pin (-15Vtest). When it returns to normal, the MCU detects a high-level signal on the pin (-15Vtest).

[0049] The communication protection circuit determines whether a communication failure occurs by the frequency of information reported by the inverter to the inverter tester; if the inverter does not report the switch quantity and analog quantity information to the inverter test controller within the time Δt, it is determined that the communication between the two has failed, that is, it is determined that a communication failure has occurred, and the MCU locks the inverter process to perform communication protection.

[0050] On the one hand, the inverter test controller generates a PWM waveform and sends the PWM signal to the inverter's MCU through optical fiber to drive the on and off of the IGBT tube. On the other hand, the inverter test controller sends the received fault signal and analog signal to the host computer software through the serial port.

[0051] The host computer software displays the data information reported by the inverter test controller and the start of the inverter process in real time.

[0052] The rectifier circuit is used to rectify the 380V AC signal into a DC signal and then supply power to the MCU and charge the CD capacitor.

[0053] Embodiment 1:

[0054] The system includes an inverter circuit, a pulse drive and protection circuit, a voltage protection circuit, a temperature protection circuit, a phase loss protection circuit, a 15V power supply protection circuit, a communication protection circuit, a rectifier circuit, an inverter test controller and a host computer software; the inverter circuit includes four IGBT chips, namely IGBT1, IGBT2, IGBT3 and IGBT4; the pulse drive and protection circuit is connected to the gates of the four IGBT chips in the inverter circuit; in the inverter circuit, chips IGBT1 and IGBT2 are connected in series, chips IGBT3 and IGBT4 are connected in series, the two series circuits are connected in parallel, and both ends of the parallel circuit are connected to the rectifier circuit, one end of the capacitor CD is connected to the emitter of IGBT2 and IGBT4 and then connected to the rectifier circuit, and the other end is connected to the collector of IGBT1 and IGBT3 and then connected to the rectifier circuit; in the system, the inverter test controller is connected to the MCU of the inverter through an optical fiber, and is connected to the host computer software through a serial port; the rectifier circuit in the system is connected to the 380V AC power supply and the MCU of the inverter respectively;

[0055] The pulse drive and protection circuit monitors faults in the circuit by monitoring the hardware cold soldering problems of any bridge arm in the inverter circuit; the voltage protection circuit determines whether there is a voltage fault by monitoring overvoltage and undervoltage problems; the temperature protection circuit detects whether a fault occurs by comparing the voltage value corresponding to the bridge arm temperature obtained by comparing the external thermistor; the missing item protection circuit determines whether a missing item occurs in the circuit through the pin signal on the MCU; the 15V power supply protection circuit determines whether the 15V power supply fails by detecting the pin signal connected to the MCU; the communication protection circuit determines whether a communication fault occurs by detecting the amount of information received by the inverter controller and the frequency change of the received information.

[0056] The pulse drive and protection circuit can detect the cold soldering problem of any bridge arm in the inverter circuit in hardware. After the cold soldering problem is found, an early warning is issued to the MCU to lock the inverter process; IGBT1, IGBT2, IGBT3 and IGBT4 chips constitute the bridge arm in the inverter circuit, wherein IGBT1 and IGBT2 constitute the left bridge arm, and IGBT3 and IGBT4 constitute the right bridge arm; in the circuit of the pulse drive and protection circuit, chip 2SC0108T2 is the IGBT driver chip, driving the conduction and shutdown of the two IGBT tubes of the left bridge arm. When a fault occurs, the driver chip detects the fault and outputs a low-level signal at the Sox pin to protect the locking system. In normal state, the Sox pin outputs a high-level signal; the MCU determines whether the driver chip is cold soldered or a fault occurs by detecting the level signal output by the Sox pin; the MCU controls the driver chip by controlling the INL and INR pins through a pulse sequence, thereby driving the conduction and shutdown of the left and right bridge arm tubes.

[0057] The voltage protection circuit includes two parts: overvoltage protection and undervoltage protection. The voltage protection circuit divides the voltage through a sampling resistor, and after the voltage division, a comparison signal is output to the MCU pin through a reference voltage comparator. The MCU detects the occurrence of a fault by judging the high and low levels on the pin and then performs voltage protection. When overvoltage protection occurs, the MCU detects that the signal on the pin (-VDOV) is a high-level signal. When it returns to normal, it detects that the signal on the pin (-VDOV) is a low-level signal. When undervoltage protection occurs, the MCU detects that the signal on the pin (-VDUV) is a low-level signal. When it returns to normal, it detects that the signal on the pin (-VDUV) is a high-level signal.

[0058] The temperature protection circuit obtains the voltage value corresponding to the temperature of the left bridge arm through the thermistor externally connected to J8, and then outputs a comparison signal to the MCU pin through the comparator. The MCU detects the occurrence of a fault by judging the high and low levels on the pin and then performs temperature protection. When temperature protection occurs, the MCU detects that the signal on the pin (-KLH) is a low-level signal. When it returns to normal, it detects that the signal on the pin (-KLH) is a high-level signal.

[0059] The temperature protection circuit obtains the voltage value corresponding to the right bridge arm temperature through the thermistor connected to J9, and also outputs the comparison signal to the MCU pin through the comparator. The MCU detects the occurrence of a fault by judging the high and low levels on the pin and then performs temperature protection. When temperature protection occurs, the MCU detects that the signal on the pin (-KRH) is a low-level signal. When it returns to normal, it detects that the signal on the pin (-KRH) is a high-level signal.

[0060] The phase loss protection circuit is that when any phase of U, V, and W is missing, the MCU determines whether a phase loss occurs by detecting the pin signal connected to the MCU. When a phase loss fault occurs, the MCU detects a pulse signal on the pin (-Vlost). When it returns to normal, the MCU detects a low-level signal on the pin (-Vlost).

[0061] The 15V power supply protection circuit is used to detect whether the 15V power supply in the circuit fails; the 15V power supply input circuit includes two 15V power supplies. When one power supply fails, it will automatically switch to the other power supply for power supply; the MCU determines whether a fault occurs by detecting the pin signal connected to the MCU. When a fault occurs, the MCU detects a low-level signal on the pin (-15Vtest). When it returns to normal, the MCU detects a high-level signal on the pin (-15Vtest).

[0062] The communication protection circuit determines whether a communication failure occurs by the frequency of information reported by the inverter to the inverter tester; if the inverter does not report the switch quantity and analog quantity information to the inverter test controller within the time Δt=20μs, it is determined that the communication between the two has failed, that is, it is determined that a communication failure has occurred, and the MCU locks the inverter process to perform communication protection.

[0063] On the one hand, the inverter test controller generates a PWM waveform and sends the PWM signal to the inverter's MCU through optical fiber to drive the on and off of the IGBT tube. On the other hand, the inverter test controller sends the received fault signal and analog signal to the host computer software through the serial port.

[0064] The host computer software displays the data information reported by the inverter test controller and the start of the inverter process in real time.

[0065] The rectifier circuit is used to rectify the 380V AC signal into a DC signal and then supply power to the MCU and charge the CD capacitor.

[0066] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A detection system for an inverter in an aging experiment, characterized in that: The system includes an inverter circuit, a pulse drive and protection circuit, a voltage protection circuit, a temperature protection circuit, a phase loss protection circuit, a 15V power supply protection circuit, a communication protection circuit, a rectifier circuit, an inverter test controller and a host computer software; the inverter circuit includes four IGBT chips, namely IGBT1, IGBT2, IGBT3 and IGBT4; the pulse drive and protection circuit is connected to the gates of the four IGBT chips in the inverter circuit; in the inverter circuit, chips IGBT1 and IGBT2 are connected in series, chips IGBT3 and IGBT4 are connected in series, the two series circuits are connected in parallel, and both ends of the parallel circuit are connected to the rectifier circuit, one end of the capacitor CD is connected to the emitter of IGBT2 and IGBT4 and then connected to the rectifier circuit, and the other end is connected to the collector of IGBT1 and IGBT3 and then connected to the rectifier circuit; in the system, the inverter test controller is connected to the MCU of the inverter through an optical fiber, and is connected to the host computer software through a serial port; the rectifier circuit in the system is connected to the 380V AC power supply and the MCU of the inverter respectively; The pulse drive and protection circuit monitors faults in the circuit by monitoring the hardware cold soldering problems of any bridge arm in the inverter circuit; the voltage protection circuit determines whether there is a voltage fault by monitoring overvoltage and undervoltage problems; the temperature protection circuit detects whether a fault occurs by comparing the voltage value corresponding to the bridge arm temperature obtained by comparing the external thermistor; the phase loss protection circuit determines whether a phase loss occurs in the circuit through the pin signal on the MCU; the 15V power supply protection circuit determines whether the 15V power supply fails by detecting the pin signal connected to the MCU; the communication protection circuit determines whether a communication fault occurs by detecting the amount of information received by the inverter controller and the frequency change of the received information.

2. The detection system of an inverter in an aging experiment according to claim 1, characterized in that: The pulse drive and protection circuit can detect the cold soldering problem of any bridge arm in the inverter circuit in hardware. After the cold soldering problem is found, an early warning is issued to the MCU to lock the inverter process; IGBT1, IGBT2, IGBT3 and IGBT4 chips constitute the bridge arm in the inverter circuit, wherein IGBT1 and IGBT2 constitute the left bridge arm, and IGBT3 and IGBT4 constitute the right bridge arm; in the circuit of the pulse drive and protection circuit, chip 2SC0108T2 is the IGBT driver chip, driving the conduction and shutdown of the two IGBT tubes of the left bridge arm. When a fault occurs, the driver chip detects the fault and outputs a low-level signal at the Sox pin to protect the locking system. In normal state, the Sox pin outputs a high-level signal; the MCU determines whether the driver chip is cold soldered or a fault occurs by detecting the level signal output by the Sox pin; the MCU controls the driver chip by controlling the INL and INR pins through a pulse sequence, thereby driving the conduction and shutdown of the left and right bridge arm tubes.

3. The detection system of an inverter in an aging experiment according to claim 1, characterized in that: The voltage protection circuit includes two parts: overvoltage protection and undervoltage protection. The voltage protection circuit divides the voltage through a sampling resistor, and after the voltage division, a comparison signal is output to the MCU pin through a voltage comparator. The MCU detects the occurrence of a fault by judging the high and low levels on the pin and then performs voltage protection. When overvoltage protection occurs, the MCU detects that the signal on the pin (-VDOV) is a high-level signal. When it returns to normal, it detects that the signal on the pin (-VDOV) is a low-level signal. When undervoltage protection occurs, the MCU detects that the signal on the pin (-VDUV) is a low-level signal. When it returns to normal, it detects that the signal on the pin (-VDUV) is a high-level signal.

4. The detection system of an inverter in an aging experiment according to claim 1, characterized in that: The temperature protection circuit obtains the voltage value corresponding to the temperature of the left bridge arm through the thermistor externally connected to the connector J8, and then outputs a comparison signal to the MCU pin through the comparator. The MCU detects the occurrence of a fault by judging the high and low levels on the pin and then performs temperature protection. When temperature protection occurs, the MCU detects that the signal on the pin (-KLH) is a low-level signal. When it returns to normal, it detects that the signal on the pin (-KLH) is a high-level signal. The temperature protection circuit obtains the voltage value corresponding to the right bridge arm temperature through the thermistor connected to connector J9, and also outputs a comparison signal to the MCU pin through the comparator. The MCU detects the occurrence of a fault by judging the high and low levels on the pin and then performs temperature protection. When temperature protection occurs, the MCU detects that the signal on the pin (-KRH) is a low-level signal. When it returns to normal, it detects that the signal on the pin (-KRH) is a high-level signal.

5. The detection system of an inverter in an aging experiment according to claim 1, characterized in that: The phase loss protection circuit is that when any phase of U, V, and W is missing, the MCU determines whether a phase loss occurs by detecting the pin signal connected to the MCU. When a phase loss fault occurs, the MCU detects a pulse signal on the pin (-Vlost). When it returns to normal, the MCU detects a low-level signal on the pin (-Vlost).

6. The detection system of an inverter in an aging experiment according to claim 1, characterized in that: The 15V power supply protection circuit is used to detect whether the 15V power supply in the circuit fails; the 15V power supply input circuit includes two 15V power supplies. When one power supply fails, it will automatically switch to the other power supply for power supply; the MCU determines whether a fault occurs by detecting the pin signal connected to the MCU. When a fault occurs, the MCU detects a low-level signal on the pin (-15Vtest). When it returns to normal, the MCU detects a high-level signal on the pin (-15Vtest).

7. The detection system of an inverter in an aging experiment according to claim 1, characterized in that: The communication protection circuit determines whether a communication failure occurs by the frequency of information reported by the inverter to the inverter test controller; if the inverter does not report the switch quantity and analog quantity information to the inverter test controller within the time Δt, it is determined that the communication between the two has failed, that is, it is determined that a communication failure has occurred, and the MCU locks the inverter process to perform communication protection.

8. The detection system of an inverter in an aging experiment according to claim 1, characterized in that: On the one hand, the inverter test controller generates a PWM waveform and sends the PWM signal to the inverter's MCU through optical fiber to drive the on and off of the IGBT tube. On the other hand, the inverter test controller sends the received fault signal and analog signal to the host computer software through the serial port.

9. The detection system of an inverter in an aging experiment according to claim 1, characterized in that: The host computer software displays the data information reported by the inverter test controller and the start of the inverter process in real time.

10. The detection system of an inverter in an aging experiment according to claim 1, characterized in that: The rectifier circuit is used to rectify the 380V AC signal into a DC signal and then supply power to the MCU and charge the CD capacitor.

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