Vehicle-mounted high-voltage inverter power supply insulation detection device

Abstract

The utility model relates to the technical field of insulation detection, and discloses a vehicle-mounted high-voltage inverter power supply insulation detection device which comprises an insulation detection starting circuit, an insulation resistance detection circuit and a detection feedback circuit. The insulation resistance detection circuit comprises a first resistance voltage division loop and a second resistance voltage division loop, and the detection feedback circuit comprises a signal processing circuit and a sound-light alarm loop. According to the utility model, the connection or disconnection of the first resistance voltage division loop and the second resistance voltage division loop is controlled to realize the unbalanced bridge of the insulation resistance detection circuit, and the voltage values of the two resistance voltage division loops are read through the signal processing circuit, so that the insulation resistance values R + and R-of the high-voltage inverter power supply to be detected are calculated. The circuit has the characteristics of light weight, miniaturization and fast response speed, a sampling loop is isolated from a signal loop through signal processing, and the sampling precision is improved. And the unbalanced bridge for detecting the insulation resistance is realized by controlling the relay, so that the detection accuracy is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of insulation detection, specifically relates to a vehicle high voltage inverter power supply insulation detection device. BACKGROUND

[0002] With the penetration rate of new energy vehicles in the automobile field increasing, the vehicle inverter power supply as an important part of DC / AC electric energy conversion of new energy vehicles, the global new energy vehicle combustion accident occurs frequently, and the solution of new energy vehicle system safety problem is paid more and more attention. In the driving vehicle environment, the safety of inverter power supply mainly acts on the performance stability during electric energy conversion, so as to drive the load to run smoothly without accident, and the insulation performance of inverter power supply directly affects the safety of use, therefore, the high voltage DC insulation detection problem of vehicle inverter power supply is urgent to be solved and evaluated. Specifically, the insulation resistance values of the positive electrode of the DC inverter power supply to the ground and the negative electrode to the ground are analyzed by the insulation monitoring means to judge the safety of the inverter power supply during charging and discharging, and the safety hidden danger is found out in advance and the warning is given.

[0003] At present, the insulation detection of DC inverter power supply mainly has two ways of balanced bridge inspection and low frequency signal monitoring. However, the balanced bridge measurement principle is difficult to distinguish the case that the insulation resistance of the positive electrode of the power supply to the ground or the chassis and the negative electrode of the power supply to the ground or the chassis decreases at the same time, and the insulation resistance value is difficult to calculate; and the low frequency detection principle is easy to be restricted by the distributed capacitance of the DC system to the ground, and the frequency band signal of dozens of hertz to hundreds of hertz is also very disturbed by the outside world, and the alternating current signal increases the voltage ripple coefficient in the DC inverter power supply system. SUMMARY

[0004] In order to solve the problems and deficiencies in the prior art, the utility model provides a kind of vehicle high voltage inverter power supply insulation detection device, the device is based on the insulation detection circuit of unbalanced bridge, uses high voltage relay to switch the insulation detection circuit, and the whole detection device has the advantages of high sensitivity and high reliability.

[0005] In order to realize the above-mentioned invention purpose, the technical scheme of the utility model is as follows:

[0006] The utility model provides a kind of vehicle-mounted high-voltage inverter power supply insulation detection device, the detection device includes insulation detection starting circuit, first resistance voltage division loop, second resistance voltage division loop, bridge arm circuit, signal processing circuit and acousto-optic alarm loop;Wherein, the input end of the first resistance voltage division loop is connected with the anode of high-voltage inverter power supply, and the output end is connected with the input end of bridge arm circuit, the output end of the bridge arm circuit is connected with the input end of second resistance voltage division loop, and the output end of the second resistance voltage division loop is connected with the cathode of high-voltage inverter power supply;One end of the insulation detection starting circuit is connected into bridge arm circuit, and the other end is grounded, and the insulation detection starting circuit is also connected with DSP minimum system;The output end of the first resistance voltage division loop has voltage sampling point V01, the input end of the second resistance voltage division loop has voltage sampling point V03, the connecting point of bridge arm circuit and insulation detection starting circuit is provided with voltage sampling point V02, voltage sampling point V01, voltage sampling point V02 and voltage sampling point V03 are respectively connected into signal processing circuit, and the output end of signal processing circuit is connected with DSP minimum system;The acousto-optic alarm loop is connected with DSP minimum system.

[0007] As preferably, the insulation detection starting circuit includes relay KM2, one end of the coil of the relay KM2 is connected into bridge arm circuit, and the other end is grounded;The auxiliary contact of the relay KM2 is connected with DSP minimum system at one end, and is grounded at the other end.

[0008] As preferably, the first resistance voltage division loop includes relay KM1 and resistance R1, resistance R2, resistance R3, resistance R4, resistance R5 and resistance R6 connected in series, the input end of the resistance R1 is connected with the anode of high-voltage inverter power supply, the output end of the resistance R6 is connected with the input end of bridge arm circuit, the coil of the relay KM1 is connected across resistance R4 and resistance R6, the auxiliary contact of relay KM1 is connected with DSP minimum system at one end, and is grounded at the other end.

[0009] As preferably, the second resistance voltage division loop includes relay KM3 and resistance R9, resistance R10, resistance R11, resistance R12, resistance R13 and resistance R14 connected in series, the output end of the resistance R9 is connected with the cathode of high-voltage inverter power supply, the input end of the resistance R14 is connected with the output end of bridge arm circuit, the coil of the relay KM3 is connected across resistance R12 and resistance R14, the auxiliary contact of relay KM3 is connected with DSP minimum system at one end, and is grounded at the other end.

[0010] As preferably, the bridge arm circuit includes resistance R7 and resistance R8 connected in series, the input end of resistance R7 is connected with the output end of first resistance voltage division loop, and the output end of resistance R8 is connected with the input end of second resistance voltage division loop.

[0011] As preferably, the signal processing circuit comprises a positive electrode voltage sampling circuit and a negative electrode voltage sampling circuit; wherein,

[0012] The positive electrode voltage sampling circuit comprises a first operational amplifier and a first parallel LC filter loop, the sampling point V01 is connected with the positive input end of the first operational amplifier through the resistance R26, the sampling point V02 is connected with the negative input end of the first operational amplifier through the resistance R24, and the first parallel LC filter loop is connected between the connection point of the resistance R26 and the positive input end of the first operational amplifier and the ground potential; the resistance R23 is arranged in parallel on the first operational amplifier;

[0013] The negative electrode voltage sampling circuit comprises a second operational amplifier and a second parallel LC filter, the sampling point V02 is connected with the positive input end of the second operational amplifier through the resistance R21, the sampling point V03 is connected with the negative input end of the second operational amplifier through the resistance R19, and the second parallel LC filter loop is connected between the connection point of the resistance R21 and the positive input end of the second operational amplifier and the ground potential; the resistance R17 is arranged in parallel on the second operational amplifier.

[0014] As preferably, the first parallel LC filter loop comprises the resistance R27 and the capacitor C25 connected in parallel; and the second parallel LC filter loop comprises the resistance R22 and the capacitor C23 connected in parallel.

[0015] As preferably, the sound-light alarm loop comprises a triode Q1, a buzzer LS1 and an alarm lamp D1, the base of the triode Q1 is connected with the DSP minimum system, the collector of the triode Q1 is connected with the control power supply through the resistance R18, the buzzer LS1 and the alarm lamp D1 are connected in parallel, one end of which is connected with the emitter of the triode Q1, and the other end is grounded.

[0016] The utility model discloses the beneficial effects of:

[0017] 1, the utility model has light weight, miniaturization characteristics, through signal processing, the sampling circuit is isolated with signal circuit, improves sampling accuracy, and through the control relay, realizes the non - balance electric bridge of insulation resistance detection, to improve the detection accuracy.

[0018] 2, the utility model responds fast, realizes man -machine interaction through the DSP minimum system calculation control sound -light alarm loop, is easy to maintain use, and the reliability is high.

[0019] 3, the utility model designs loop high voltage value, can be widely used in vehicle -mounted power inverter power platform, and the scope of application is wide, and the safety of inverter power supply is improved significantly.

[0020] 4, The insulation detection starting circuit of the utility model can disconnect the ground when the device is in a non-working state or a fault occurs, reduce the power consumption, and ensure the safety of personnel and equipment in the vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0021] The foregoing and the following detailed description of the utility model become clearer when read in conjunction with the following drawings, in which:

[0022] Figure 1 It is the insulation resistance detection circuit structure diagram of the utility model detection device;

[0023] Figure 2 It is the positive electrode voltage sampling circuit structure diagram of the utility model;

[0024] Figure 3 It is the negative electrode voltage sampling circuit structure diagram of the utility model;

[0025] Figure 4 It is the sound and light alarm loop structure diagram of the utility model. DETAILED DESCRIPTION

[0026] In order to make those skilled in the art better understand the technical scheme in the utility model, the following will be further explained by several specific embodiments to realize the technical scheme of the utility model, and it should be noted that the technical scheme claimed by the utility model includes but is not limited to the following embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor should belong to the protection scope of the utility model.

[0027] Embodiment 1

[0028] The embodiment discloses a kind of vehicle-mounted high-voltage inverter power supply insulation detection device, the detection device is by insulation detection starting circuit, insulation resistance detection circuit and detection feedback circuit composition;Wherein, the insulation resistance detection circuit includes first resistance voltage divider loop, second resistance voltage divider loop and bridge arm circuit, the detection feedback circuit includes signal processing circuit and sound and light alarm loop.

[0029] As shown in Figure 1 The insulation detection starting circuit includes relay KM2, the coil one end of relay KM2 is connected into bridge arm circuit, the other end is connected with the shell of vehicle chassis or with the GND end of ground wire, the input end ADCON3 of auxiliary contact of the relay KM2 is connected with the minimum system of DSP, the other end is connected with digital ground DGND, only when the relay KM2 of insulation detection starting circuit is attracted, the whole detection device carries out insulation detection, avoids high-voltage inverter power supply power consumption after vehicle is turned off insulation detection device work.

[0030] AsFigure 1 As shown in the figure, the first resistance voltage dividing circuit comprises a relay KM1 and resistors R1, R2, R3, R4, R5 and R6 connected in series, the input end of the resistor R1 is connected with the positive output of the high-voltage inverter power supply, the output end of the resistor R6 is connected with the input end of the bridge arm circuit, the coil of the relay KM1 is connected in parallel between the resistor R4 and the resistor R6, the input end ADCON1 of the auxiliary contact of the relay KM1 is connected with the minimum system of the DSP, and the other end is connected with the digital ground DGND. Moreover, the output end of the first resistance voltage dividing circuit is provided with a voltage sampling point V01, and the output signal of the voltage sampling point V01 is connected with the signal processing circuit.

[0031] As shown in the figure, Figure 1 As shown in the figure, the second resistance voltage dividing circuit comprises a relay KM3 and resistors R9, R10, R11, R12, R13 and R14 connected in series, the output end of the resistor R9 is connected with the negative output of the high-voltage inverter power supply, the input end of the resistor R14 is connected with the output end of the bridge arm circuit, the coil of the relay KM3 is connected in parallel between the resistor R12 and the resistor R14, the input end ADCON3 of the auxiliary contact of the relay KM3 is connected with the minimum system of the DSP, and the other end is connected with the digital ground DGND. Moreover, the output end of the second resistance voltage dividing circuit is provided with a voltage sampling point V03, and the output signal of the voltage sampling point V03 is connected with the signal processing circuit.

[0032] As shown in the figure, Figure 1 As shown in the figure, the bridge arm circuit comprises resistors R7 and R8 connected in series, the input end of the resistor R7 is connected with the output end of the first resistance voltage dividing circuit, and the output end of the resistor R8 is connected with the input end of the second resistance voltage dividing circuit. The relay KM2 is used as a starting circuit, one end of the starting circuit is connected with an arbitrary point in the bridge arm circuit, the circuit between the middle point and the positive electrode is used as the positive bridge arm circuit, the circuit between the middle point and the negative electrode is used as the negative bridge arm circuit, and the middle point is provided with a voltage sampling point V02. The output signal of the voltage sampling point V02 is connected with the signal processing circuit.

[0033] The signal processing circuit comprises a positive voltage sampling circuit and a negative voltage sampling circuit, as shown in the figure, Figure 2As shown, the positive electrode voltage sampling circuit comprises a first operational amplifier and a first parallel LC filter circuit, the sampling point V01 is connected with the positive input end of the first operational amplifier through a resistor R26, the first parallel LC filter circuit is arranged between the output end of the resistor R26 and the positive input end of the first operational amplifier, and the sampling point V02 is connected with the negative input end of the first operational amplifier through a resistor R24; the output end ADC0 of the first operational amplifier is connected with the input end of the DSP minimum system, and a resistor R23 is further arranged in parallel on the first operational amplifier, one end of the resistor R23 is connected between the output end of the resistor R24 and the negative input end of the first operational amplifier, and the other end is connected with the output end ADC0 of the first operational amplifier.

[0034] The negative electrode voltage sampling circuit comprises a second operational amplifier and a second parallel LC filter, the sampling point V02 is connected with the positive input end of the second operational amplifier through a resistor R21, the second parallel LC filter circuit is arranged between the output end of the resistor R21 and the positive input end of the second operational amplifier, and the sampling point V03 is connected with the negative input end of the second operational amplifier through a resistor R19; the output end ADC1 of the second operational amplifier is connected with the input end of the DSP minimum system, and a resistor R17 is further arranged in parallel on the second operational amplifier, one end of the resistor R17 is connected between the output end of the resistor R19 and the negative input end of the second operational amplifier, and the other end is connected with the output end ADC1 of the second operational amplifier.

[0035] Further, the first parallel LC filter circuit comprises a resistor R27 and a capacitor C25 connected in parallel, one end of the parallel circuit of the resistor R27 and the capacitor C25 is connected between the resistor R26 and the positive input end of the first operational amplifier, and the other end is connected with the analog ground AGND; the second parallel LC filter circuit comprises a resistor R22 and a capacitor C23 connected in parallel, one end of the parallel circuit of the resistor R22 and the capacitor C23 is connected between the resistor R21 and the positive input end of the second operational amplifier, and the other end is connected with the analog ground AGND.

[0036] In the embodiment depicted in the utility model, two resistance voltage dividing circuits collect values respectively as Vo1, Vo2 and Vo3, wherein Vo1 is the voltage between the resistor R6 and the resistor R7, Vo2 is the voltage between the resistor R7 and the resistor R8, and Vo3 is the voltage between the resistor R8 and the resistor R14. It should be noted that in the first resistance voltage dividing circuit, the sum of the resistance values of the resistor R1, the resistor R2, the resistor R3, the resistor R4, the resistor R5 and the resistor R6 is equal to the sum of the resistance values of the resistor R9, the resistor R10, the resistor R11, the resistor R12, the resistor R13 and the resistor R14 in the second resistance voltage dividing circuit, and the resistance value of the resistor R7 is not equal to the resistance value of the resistor R8, so as to realize an unbalanced bridge.

[0037] In the embodiment depicted in the utility model, for the first parallel LC filter circuit, the resistance of resistance 27 is the same as the resistance of resistance R26; and in the positive voltage sampling circuit, the resistance of resistance R23 is equal to the resistance of resistance R24, the first operational amplifier output signal is the positive voltage signal ADC0, and the value ADC0=Vo1-Vo2. For the second parallel LC filter circuit, the resistance of resistance R22 is the same as the resistance of resistance R21, and in the negative voltage sampling circuit, the resistance of resistance R19 is the same as the resistance of resistance R17, the second operational amplifier output signal is the positive voltage signal ADC1, and the value ADC1=Vo2-Vo3.

[0038] It can be understood that the signal processing circuit of the utility model has a signal differential amplification function, and the processed signals ADC0 and ADC1 are sent to the DSP minimum system. Figure 4 The sound and light alarm circuit structure diagram is as shown in Figure 4 The sound and light alarm circuit includes a triode Q1, a buzzer LS1 and an alarm lamp D1, the alarm lamp D1 is usually an LED lamp; the base of the triode Q1 is connected with the DSP minimum system, the collector of the triode Q1 is connected with the control power supply of the DSP minimum system through resistance R18, the buzzer LS1 and the alarm lamp D1 are connected in parallel, one end of the parallel connection circuit of the two is connected with the emitter of the triode Q1, and the other end is connected with digital ground DGND.

[0039] It can be understood that the high-voltage inverter power supply insulation detection device of the utility model can be arranged on the output interface of the vehicle-mounted high-voltage inverter power supply output end, and can also be arranged on the DC bus of the vehicle-mounted high-voltage inverter power supply.

[0040] Embodiment 2

[0041] The embodiment discloses a vehicle-mounted high-voltage inverter power supply insulation detection device, and the working process and principle of the device are as follows:

[0042] Step S101. First, the high-voltage relay KM2 is attracted in the insulation detection starting store, the high-voltage relay KM2 is connected with the vehicle chassis or grounded, so that the high-voltage inverter power supply can be output to the insulation resistance detection circuit;

[0043] Step S102. The relay KM1 in the insulation resistance detection circuit is attracted and the relay KM3 is simultaneously disconnected. The voltage values V01 and V02 at both ends of the resistor R7 after the positive electrode of the high-voltage inverter power supply is divided by the first resistance voltage dividing circuit are read. The two voltage signals are processed and converted by the positive electrode voltage sampling circuit of the signal processing circuit and then output to the DSP minimum system to obtain the positive electrode-to-ground voltage value ADC01. The voltage values V02 and V03 at both ends of the resistor R8 after the negative electrode of the high-voltage inverter power supply is divided by the second resistance voltage dividing circuit are read. The two voltage signals are processed and converted by the negative electrode voltage sampling circuit of the signal processing circuit and then output to the DSP minimum system to obtain the negative electrode-to-ground voltage value ADC11. According to the voltage dividing principle, we have:

[0044]

[0045] wherein, R a == R1+R2+R3; R c == R9+R10+R11; R a == R c ; R d == R12+R13+R14.

[0046] Step S103. It is determined by the command line of the DSP minimum system whether the switching relay has been performed. If the switching relay has not been performed, step S104 is entered. If the switching relay has been performed, step S105 is entered.

[0047] Step S104. The relay KM3 in the insulation resistance detection circuit is attracted and the relay KM1 is simultaneously disconnected. The positive electrode-to-ground voltage value ADC02 output after the positive electrode of the high-voltage inverter power supply is divided and sampled is obtained, and the negative electrode-to-ground voltage value ADC12 output after the negative electrode of the high-voltage inverter power supply is divided and sampled is obtained. The insulation resistances R+ and R- of the high-voltage inverter power supply are calculated by the equation form. According to the voltage dividing principle, we have:

[0048]

[0049] wherein, R d == R d == R4+R5+R6.

[0050] The insulation resistances R+ and R- of the high-voltage inverter power supply are calculated by the equations (1) and (2). Wherein,

[0051]

[0052] Step S105. Further, when the detected insulation resistances R+ and R- of the high-voltage inverter power supply are lower than the set protection threshold, step S106 is entered. Otherwise, the process of steps S102 to S105 is continued.

[0053] Step S106. Immediately automatically reduce voltage, limit current and cut off the DC circuit, and alarm through the acousto-optic alarm circuit, realize human-computer interaction.

[0054] The above is only the preferred embodiment of the present application, and does not limit the present application in any form, and any simple modification, equivalent change of the above embodiment according to the technical essence of the present application falls within the protection scope of the present application.

Claims

1. An insulation testing device for vehicle-mounted high-voltage inverter power supplies, characterized in that, The application relates to an insulation detection starting circuit, a first resistance voltage dividing circuit, a second resistance voltage dividing circuit, a bridge arm circuit, a signal processing circuit and an acousto-optic alarm circuit; wherein the input end of the first resistance voltage dividing circuit is connected with the positive pole of a high-voltage inverter power supply, the output end is connected with the input end of the bridge arm circuit, the output end of the bridge arm circuit is connected with the input end of the second resistance voltage dividing circuit, and the output end of the second resistance voltage dividing circuit is connected with the negative pole of the high-voltage inverter power supply; one end of the insulation detection starting circuit is connected with the bridge arm circuit, and the other end is grounded, and the insulation detection starting circuit is further connected with a DSP minimum system; the output end of the first resistance voltage dividing circuit has a voltage sampling point V01, the input end of the second resistance voltage dividing circuit has a voltage sampling point V03, and the connection point of the bridge arm circuit and the insulation detection starting circuit is provided with a voltage sampling point V02; the voltage sampling point V01, the voltage sampling point V02 and the voltage sampling point V03 are respectively connected with the signal processing circuit, and the output end of the signal processing circuit is connected with the DSP minimum system; and the acousto-optic alarm circuit is connected with the DSP minimum system.

2. The insulation detection device for a high-voltage inverter power supply of claim 1, wherein The insulation detection starting circuit comprises a relay KM2, one end of the coil of the relay KM2 is connected with the bridge arm circuit, and the other end is grounded; one end of the auxiliary contact of the relay KM2 is connected with the DSP minimum system, and the other end is grounded.

3. The insulation detection device for a high-voltage inverter power supply of claim 1, wherein The first resistance voltage dividing circuit comprises a relay KM1 and resistors R1, R2, R3, R4, R5 and R6 which are connected in series, the input end of the resistor R1 is connected with the positive pole of the high-voltage inverter power supply, the output end of the resistor R6 is connected with the input end of the bridge arm circuit, the coil of the relay KM1 is connected in parallel between the resistor R4 and the resistor R6, one end of the auxiliary contact of the relay KM1 is connected with the DSP minimum system, and the other end is grounded.

4. The insulation detection device for a high-voltage inverter power supply of claim 1, wherein The second resistance voltage dividing circuit comprises a relay KM3 and resistors R9, R10, R11, R12, R13 and R14 which are connected in series, the output end of the resistor R9 is connected with the negative pole of the high-voltage inverter power supply, the input end of the resistor R14 is connected with the output end of the bridge arm circuit, the coil of the relay KM3 is connected in parallel between the resistor R12 and the resistor R14, one end of the auxiliary contact of the relay KM3 is connected with the DSP minimum system, and the other end is grounded.

5. The insulation detection device for a high-voltage inverter power supply of claim 1, wherein The signal processing circuit comprises a positive pole voltage sampling circuit and a negative pole voltage sampling circuit; wherein the sampling point V01 is connected with the positive pole voltage sampling circuit, the sampling point V03 is connected with the negative pole voltage sampling circuit, and the sampling point V02 is simultaneously connected with the positive pole voltage sampling circuit and the negative pole voltage sampling circuit.

6. The insulation detection device for a high-voltage inverter power supply of claim 5, wherein The positive electrode voltage sampling circuit comprises a first operational amplifier and a first parallel LC filter circuit, the sampling point V01 is connected with the positive input end of the first operational amplifier through the resistance R26, the sampling point V02 is connected with the negative input end of the first operational amplifier through the resistance R24, and the first parallel LC filter circuit is connected between the connection point of the resistance R26 and the positive input end of the first operational amplifier and the ground potential; the resistance R23 is arranged in parallel on the first operational amplifier.

7. The insulation detection device for a high-voltage inverter power supply of claim 5, wherein the insulation detection device further comprises a high-voltage insulation detection circuit. The negative electrode voltage sampling circuit comprises a second operational amplifier and a second parallel LC filter circuit, the sampling point V02 is connected with the positive input end of the second operational amplifier through the resistance R21, the sampling point V03 is connected with the negative input end of the second operational amplifier through the resistance R19, and the second parallel LC filter circuit is connected between the connection point of the resistance R21 and the positive input end of the second operational amplifier and the ground potential; the resistance R17 is arranged in parallel on the second operational amplifier.

8. The insulation detection device for a high-voltage inverter power supply of claim 6, wherein The first parallel LC filter circuit comprises the resistance R27 and the capacitor C25 connected in parallel.

9. The insulation detection device for a high-voltage inverter power supply of claim 7, wherein the insulation detection device further comprises a high-voltage insulation detection circuit. The second parallel LC filter circuit comprises the resistance R22 and the capacitor C23 connected in parallel.

10. The insulation detection device for a high-voltage inverter power supply of claim 1, wherein The sound-light alarm circuit comprises a triode Q1, a buzzer LS1 and an alarm lamp D1, the base of the triode Q1 is connected with the DSP minimum system, the collector of the triode Q1 is connected with the control power supply through the resistance R18, the buzzer LS1 and the alarm lamp D1 are connected in parallel, one end of which is connected with the emitter of the triode Q1, and the other end is grounded.

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