Detection circuit for high-voltage measurement of insulation resistance value based on solid-state optocoupler relay

Abstract

The utility model belongs to the technical field of electronics, and relates to a detection circuit for high-voltage measurement of insulation resistance based on a solid-state optocoupler relay, when control signals output by an MCU in the detection circuit are HVPI NIOPP and HVP + I NIO, U27 and U34 in the detection circuit are conducted, and a voltage follower U29A is used for measuring the voltage U1 of a total voltage negative to a shell CAMP; when the control signals output by the MCU in the detection circuit are HVPI NIO and HVP-I NIO, U31 and U44 are conducted, and a voltage follower U29B measures the voltage U2 of the total voltage directly facing the shell CAMP; a series connection mode of U36, U27, U31, U34 and U44 is adopted, large voltage is increased, current in a loop is reduced during detection, and the withstand voltage value of the detection circuit is improved; a divider resistor group is used for dividing voltage, and a voltage follower is added, so that coupling of external interference is reduced, and the measurement precision is improved; and an isolated power supply mode is adopted, so that the complete isolation of the battery end and the MCU processing end is met.

Description

Technical Field

[0001] The utility model belongs to the technical field of electronics, and in particular relates to a detection circuit based on high-voltage insulation resistance measurement of a solid-state optical coupler relay. Background Art

[0002] The maximum load voltage of current optocoupler relays is only 1500V, which does not meet the high insulation voltage measurement requirements;

[0003] The current insulation resistance measurement circuit has low accuracy and is not completely disconnected from the measurement loop. Additional resistance is introduced during the measurement process, affecting the normal use of the circuit. Utility Model Content

[0004] The purpose of the utility model is to overcome the deficiencies in the prior art and to provide a detection circuit for measuring insulation resistance based on a solid-state optical coupler relay at high voltage.

[0005] In order to achieve the purpose of the present invention, the present invention will be implemented by adopting the technical solution described below.

[0006] A detection circuit for measuring insulation resistance at high voltage based on a solid-state optocoupler relay includes a microcontroller unit (MCU), an analog-to-digital converter (ADC), and a high-voltage measurement unit. The high-voltage measurement unit includes a high-voltage switching unit and a measurement unit. The MCU controls the high-voltage switching unit to perform high-voltage switching. The measurement unit converts the measured analog signal into a digital signal via the ADC and transmits the digital signal to the MCU for insulation resistance calculation. The circuit is characterized by:

[0007] The high-voltage switching unit includes solid-state optocoupler relays U36, U27, U31, U34 and U44 connected in series; the measuring unit includes two voltage followers U29A and U29B;

[0008] The control end of the MCU output control signal HVP_IN_IO_PP is connected to the base of Q9, the collector of Q9 is connected to pin 5 of U36, pin 4 of U36 is connected to pin 5 of U27, pins 15 and 16 of U27 are connected to the positive input pin 3 of U29A through the voltage divider resistor group R1, and the voltage signal output by pins 15 and 16 of U27 is MIDHV;

[0009] The control end of the control signal HVP_IN_IO output by the MCU is connected to the base of Q4, the collector of Q4 is connected to pin 5 of U31, and pins 9 and 10 of U31 are connected to the positive input pin 5 of U29B through the voltage divider resistor group R2. The voltage signal output by pins 9 and 10 of U31 is OUT HV+;

[0010] The control end of the control signal HVP+_IN_IO output by the MCU is connected to the base of Q5, the collector of Q5 is connected to pin 5 of U34, and pins 9 and 10 as well as pins 15 and 16 of U34 are connected to the connection line between pins 9 and 10 of U31 and the voltage divider resistor group R2 through the voltage divider resistor groups R3 and R4 respectively, wherein the voltage signal output by pins 15 and 16 of U34 is MIDHV;

[0011] The control end of the control signal HVP-_IN_IO output by the MCU is connected to the base of Q6, the collector of Q6 is connected to pin 5 of U44, pins 9 and 10 as well as pins 15 and 16 of U44 are connected to GND C through voltage divider resistor groups R5 and R6 respectively, and the voltage signal output by pins 9 and 10 of U44 is MIDHV;

[0012] Wherein, pin 4 of U34 is connected to pin 4 of U44;

[0013] Pins 9 and 10 of U34 are connected to pins 9 and 10 of U44;

[0014] Pins 4 of U27, U31, U34 and U44 are connected to the positive electrode of the +5V working power supply through resistors R112, R358, R197 and R198 respectively;

[0015] Pins 9 and 10 of U36 are connected to the housing CAMP, and pins 15 and 16 are connected to GND HV;

[0016] The digital signal is transmitted to the MCU through an isolation digital chip.

[0017] As a further solution of the present invention, the housing CAMP is the housing of the battery pack VPACK to be tested.

[0018] As a preferred solution of the present invention, the positive electrode HV+ of the battery pack to be tested VPACK is connected to pins 15 and 16 of U31, and the negative electrode HV- thereof is connected to GND C.

[0019] As a preferred embodiment of the present invention, the R1 includes R115, R116, R117, R118, R119, R120 and R121 connected in series;

[0020] The R2 includes R148, R149, R150, R151, R152, R153 and R154 connected in series;

[0021] The R3 includes R166, R172, R173, R174, R175 and R176 connected in series;

[0022] The R4 includes R177, R178, R179, R180, R181 and R182 connected in series;

[0023] The R5 includes R185, R186, R187, R188, R189 and R190 connected in series;

[0024] The R6 includes R191, R192, R193, R194, R195 and R196 connected in series.

[0025] As a preferred solution of the present invention, the output end of U29A is connected to GND C via a resistor R113 and a capacitor C123 connected in series.

[0026] As a preferred solution of the present invention, the output end of U29B is connected to GND C via a resistor R147 and a capacitor C127 connected in series.

[0027] As a preferred solution of the present invention, pins 9 and 10 of U27 are connected to GND HV.

[0028] As a preferred solution of the present invention, when the control signals output by the MCU are HVP_IN_IO_PP and HVP+_IN_IO, U27 and U34 are turned on, and the measuring unit measures the voltage U1 of the total pressure negative to the housing CAMP.

[0029] As a preferred solution of the present invention, when the control signals output by the MCU are HVP_IN_IO and HVP-_IN_IO, U31 and U44 are turned on, and the measuring unit measures the voltage U2 of the total pressure facing the housing CAMP.

[0030] As a preferred solution of the present invention, Q9, Q4, Q5 and Q6 are common emitter amplifier circuits, and the emitters of Q9, Q4, Q5 and Q6 are all connected to GND D. Beneficial effects

[0031] Five solid-state photorelays are connected in series, and a high voltage is added to the circuit loop. During high-voltage detection, the current in the loop is reduced, which can greatly improve the circuit's withstand voltage value.

[0032] In order to meet the requirements of higher precision, high-precision resistors are used for voltage division and voltage followers are added to reduce the coupling of external interference and increase the measurement accuracy.

[0033] The isolated power supply method is used to ensure complete isolation between the battery end and the MCU processing end;

[0034] All voltage collection information is processed by the MCU. The MCU calculates the insulation resistance based on the algorithm and uploads it uniformly, saving a lot of MCU resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is the circuit schematic diagram of the utility model;

[0036] Figure 2 This is a diagram showing the process of transmitting the analog signal measured by the measurement unit of the present invention to the MCU;

[0037] Figure 3 This is a schematic diagram of the connection between the detection circuit of the utility model and the battery pack to be tested. DETAILED DESCRIPTION

[0038] The following is a detailed description of preferred embodiments of the present invention in conjunction with the accompanying drawings. It should be understood that the following embodiments are only intended to illustrate the present invention and are not intended to limit the scope of the present invention.

[0039] As an embodiment of the present utility model, Figure 1 and Figure 2 As shown, a detection circuit for high-voltage insulation resistance measurement based on a solid-state optocoupler relay includes a microcontroller unit (MCU), an analog-to-digital converter (ADC), and a high-voltage measurement unit. The high-voltage measurement unit includes a high-voltage switching unit and a measurement unit. The MCU controls the high-voltage switching unit to perform high-voltage switching. The measurement unit converts the measured analog signal into a digital signal through the ADC and transmits it to the MCU for insulation resistance calculation.

[0040] The high-voltage switching unit includes solid-state optocoupler relays U36, U27, U31, U34 and U44 connected in series; the measuring unit includes two voltage followers U29A and U29B;

[0041] The control end of the MCU output control signal HVP_IN_IO_PP is connected to the base of Q9, the collector of Q9 is connected to pin 5 of U36, pin 4 of U36 is connected to pin 5 of U27, pins 15 and 16 of U27 are connected to the positive input pin 3 of U29A through the voltage divider resistor group R1, and the voltage signal output by pins 15 and 16 of U27 is MIDHV;

[0042] The control end of the control signal HVP_IN_IO output by the MCU is connected to the base of Q4, the collector of Q4 is connected to pin 5 of U31, and pins 9 and 10 of U31 are connected to the positive input pin 5 of U29B through the voltage divider resistor group R2. The voltage signal output by pins 9 and 10 of U31 is OUT HV+;

[0043] The control end of the control signal HVP+_IN_IO output by the MCU is connected to the base of Q5, the collector of Q5 is connected to pin 5 of U34, and pins 9 and 10 as well as pins 15 and 16 of U34 are connected to the connection line between pins 9 and 10 of U31 and the voltage divider resistor group R2 through the voltage divider resistor groups R3 and R4 respectively, wherein the voltage signal output by pins 15 and 16 of U34 is MIDHV;

[0044] The control end of the control signal HVP-_IN_IO output by the MCU is connected to the base of Q6, the collector of Q6 is connected to pin 5 of U44, pins 9 and 10 as well as pins 15 and 16 of U44 are connected to GND C through voltage divider resistor groups R5 and R6 respectively, and the voltage signal output by pins 9 and 10 of U44 is MIDHV;

[0045] Pin 4 of U34 is connected to pin 4 of U44;

[0046] Pins 9 and 10 of U34 are connected to pins 9 and 10 of U44;

[0047] Pins 4 of U27, U31, U34 and U44 are connected to the positive electrode of the +5V working power supply through resistors R112, R358, R197 and R198 respectively;

[0048] Pins 9 and 10 of the U36 are connected to the housing CAMP, and pins 15 and 16 are connected to GND HV. The utility model isolates the battery pack VPACK to be tested from the detection circuit through U36.

[0049] The digital signal is transmitted to the MCU via an isolation digital chip. The utility model isolates the MCU and the detection circuit via the isolation digital chip.

[0050] As an embodiment of the present utility model, Figure 1 and Figure 3 As shown, the housing CAMP is the housing of the battery pack VPACK to be tested.

[0051] As an embodiment of the present utility model, Figure 1 and Figure 3 As shown, the positive electrode HV+ of the battery pack to be tested VPACK is connected to pins 15 and 16 of U31, and the negative electrode HV- is connected to GND C.

[0052] As an embodiment of the present utility model, Figure 1 As shown, the R1 includes R115, R116, R117, R118, R119, R120 and R121 connected in series;

[0053] The R2 includes R148, R149, R150, R151, R152, R153 and R154 connected in series;

[0054] The R3 includes R166, R172, R173, R174, R175 and R176 connected in series;

[0055] The R4 includes R177, R178, R179, R180, R181 and R182 connected in series;

[0056] The R5 includes R185, R186, R187, R188, R189 and R190 connected in series;

[0057] The R6 includes R191, R192, R193, R194, R195 and R196 connected in series.

[0058] The utility model performs voltage division through the above-mentioned voltage dividing resistor group R1, R2, R3, R4, R5, and R6.

[0059] As an embodiment of the present utility model, Figure 1 As shown, the output terminal of U29A is connected to GND C through a resistor R113 and a capacitor C123 connected in series.

[0060] As an embodiment of the present utility model, Figure 1 As shown, the output terminal of U29B is connected to GND C through a resistor R147 and a capacitor C127 connected in series.

[0061] As an embodiment of the present utility model, Figure 1 As shown, pins 9 and 10 of U27 are connected to GND HV.

[0062] As an embodiment of the present utility model, Figure 1 As shown, when the control signals output by the MCU are HVP_IN_IO_PP and HVP+_IN_IO, U27 and U34 are turned on, and the measuring unit measures the voltage U1 of the total pressure negative to the housing CAMP.

[0063] As an embodiment of the present utility model, Figure 1 As shown, when the control signals output by the MCU are HVP_IN_IO and HVP-_IN_IO, U31 and U44 are turned on, and the measuring unit measures the voltage U2 of the total pressure facing the housing CAMP.

[0064] As an embodiment of the present utility model, Figure 1 As shown, Q9, Q4, Q5 and Q6 form a common emitter amplifier circuit, and the emitters of Q9, Q4, Q5 and Q6 are all connected to GND D.

[0065] As an embodiment of the present utility model, Figure 1 and Figure 3 As shown, the collected analog signals of U1 and U2 are converted into digital signals through the ADC, and then transmitted to the MCU through the isolation digital chip for insulation resistance calculation to calculate the insulation resistance R+ and R- to be measured.

[0066] The technical solution of the present invention is described in detail above in conjunction with the embodiments / drawings, but the present invention is not limited to the above technical solution. For ordinary technicians in this technical field, after knowing the contents recorded in the present invention, they can make several equivalent changes and substitutions without departing from the principles of the present invention. These equivalent changes and substitutions should also be regarded as belonging to the scope of protection of the present invention.

Claims

1. A detection circuit for measuring insulation resistance based on a solid-state optocoupler relay at high voltage, comprising a microcontroller unit (MCU), an analog-to-digital converter (ADC), and a high-voltage measurement unit, wherein: The high-voltage measurement unit includes a high-voltage switching unit and a measuring unit; the MCU controls the high-voltage switching unit to perform high-voltage switching; the measuring unit converts the measured analog signal into a digital signal through the ADC and transmits it to the MCU for insulation resistance calculation; the characteristics are: The high-voltage switching unit includes solid-state optocoupler relays U36, U27, U31, U34 and U44 connected in series; the measuring unit includes two voltage followers U29A and U29B; The control end of the MCU output control signal HVP_IN_IO_PP is connected to the base of Q9, the collector of Q9 is connected to pin 5 of U36, pin 4 of U36 is connected to pin 5 of U27, pins 15 and 16 of U27 are connected to the positive input pin 3 of U29A through the voltage divider resistor group R1, and the voltage signal output by pins 15 and 16 of U27 is MIDHV; The control end of the control signal HVP_IN_IO output by the MCU is connected to the base of Q4, the collector of Q4 is connected to pin 5 of U31, and pins 9 and 10 of U31 are connected to the positive input pin 5 of U29B through the voltage divider resistor group R2. The voltage signal output by pins 9 and 10 of U31 is OUT HV+; The control end of the control signal HVP+_IN_IO output by the MCU is connected to the base of Q5, the collector of Q5 is connected to pin 5 of U34, and pins 9 and 10 as well as pins 15 and 16 of U34 are connected to the connection line between pins 9 and 10 of U31 and the voltage divider resistor group R2 through the voltage divider resistor groups R3 and R4 respectively, wherein the voltage signal output by pins 15 and 16 of U34 is MIDHV; The control end of the control signal HVP-_IN_IO output by the MCU is connected to the base of Q6, the collector of Q6 is connected to pin 5 of U44, pins 9 and 10 as well as pins 15 and 16 of U44 are connected to GND C through voltage divider resistor groups R5 and R6 respectively, and the voltage signal output by pins 9 and 10 of U44 is MIDHV; Wherein, pin 4 of U34 is connected to pin 4 of U44; Pins 9 and 10 of U34 are connected to pins 9 and 10 of U44; Pins 4 of U27, U31, U34 and U44 are connected to the positive electrode of the +5V working power supply through resistors R112, R358, R197 and R198 respectively; Pins 9 and 10 of U36 are connected to the housing CAMP, and pins 15 and 16 are connected to GND HV; The digital signal is transmitted to the MCU through an isolation digital chip.

2. A detection circuit based on high-voltage measurement of insulation resistance of a solid-state optical coupler relay according to claim 1, characterized in that: The housing CAMP is the housing of the battery pack VPACK to be tested.

3. A detection circuit based on high-voltage measurement of insulation resistance of a solid-state optical coupler relay according to claim 2, characterized in that: The positive electrode HV+ of the battery pack to be tested VPACK is connected to pins 15 and 16 of U31, and the negative electrode HV- thereof is connected to GNDC.

4. The detection circuit for measuring insulation resistance based on a solid-state optical coupler relay at high voltage according to claim 1, characterized in that: The R1 includes R115, R116, R117, R118, R119, R120 and R121 connected in series; The R2 includes R148, R149, R150, R151, R152, R153 and R154 connected in series; The R3 includes R166, R172, R173, R174, R175 and R176 connected in series; The R4 includes R177, R178, R179, R180, R181 and R182 connected in series; The R5 includes R185, R186, R187, R188, R189 and R190 connected in series; The R6 includes R191, R192, R193, R194, R195 and R196 connected in series.

5. The detection circuit based on high voltage measurement of insulation resistance of solid-state optical coupler relay according to claim 1, characterized in that: The output terminal of U29A is connected to GND C through a resistor R113 and a capacitor C123 connected in series.

6. A detection circuit based on high-voltage measurement of insulation resistance of a solid-state optical coupler relay according to claim 1, characterized in that: The output terminal of U29B is connected to GND C through a resistor R147 and a capacitor C127 connected in series.

7. A detection circuit based on high voltage measurement of insulation resistance of a solid-state optical coupler relay according to claim 1, characterized in that: Pins 9 and 10 of the U27 are connected to GND HV.

8. The detection circuit based on high voltage measurement of insulation resistance of solid-state optical coupler relay according to claim 1, characterized in that: When the control signals output by the MCU are HVP_IN_IO_PP and HVP+_IN_IO, U27 and U34 are turned on, and the measuring unit measures the voltage U1 of the total pressure negative to the housing CAMP.

9. The detection circuit based on high voltage measurement of insulation resistance of solid-state optical coupler relay according to claim 1, characterized in that: When the control signals output by the MCU are HVP_IN_IO and HVP-_IN_IO, U31 and U44 are turned on, and the measuring unit measures the voltage U2 of the total pressure facing the housing CAMP.

10. The detection circuit based on high voltage measurement of insulation resistance of solid-state optical coupler relay according to claim 1, characterized in that: The Q9, Q4, Q5 and Q6 are common emitter amplifier circuits, and the emitters of Q9, Q4, Q5 and Q6 are all connected to GND D.

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