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CN-224231884-U - Insulation monitor for high-voltage direct-current equipment

CN224231884UCN 224231884 UCN224231884 UCN 224231884UCN-224231884-U

Abstract

The application relates to the field of electric energy detection, in particular to an insulation monitor for high-voltage direct current equipment, which comprises a resistance detection module and a voltage detection module, wherein the resistance detection module is used for detecting the resistance value of an HV_pos end to the ground and the resistance value of the HV_neg end to the ground, and the voltage detection module is used for detecting the voltage of a high-voltage loop. The application has the effects of realizing faster reaction speed and reducing cost.

Inventors

  • YANG QUANDONG
  • YANG KAN
  • CHEN ZHUO
  • QIU ZIHAO

Assignees

  • 浙江奔一新能源有限公司

Dates

Publication Date
20260512
Application Date
20250113

Claims (9)

  1. 1. An insulation monitor for a high voltage dc device, comprising: The resistance detection module is used for detecting the resistance value of the HV_pos end to the ground and the resistance value of the HV_neg end to the ground; And the voltage detection module is used for detecting the voltage of the high-voltage loop.
  2. 2. The insulation monitor for a hvdc device according to claim 1, wherein the resistance detection module comprises: The measuring unit (1) is used for measuring the voltage drop of the HV_pos end to the ground or the voltage drop of the HV_neg end to the ground to obtain InAMC _P signals; The isolation differential unit (2) is used for receiving the InAMC _P signal, performing power supply isolation, and performing differential operation to obtain a diff_P differential signal and a diff_N differential signal; And the differential-to-single-ended unit (3) is used for receiving the Diff_P differential signal and the Diff_N differential signal, and calculating to obtain an ADC_ Insu signal, thereby obtaining the resistance value of the HV_pos end to the ground or the resistance value of the HV_neg end to the ground.
  3. 3. The insulation monitor for a high voltage direct current device according to claim 2, wherein the measuring unit (1) comprises a chip U1 and a resistor R11, an eleventh pin of the chip U1 is electrically connected to an HV_Pos terminal, a third pin of the chip U1 is electrically connected to a switch_Pos terminal, the resistor R11 is serially connected to a ninth pin of the chip U1, and the InAMC _P signal is output between the ninth pin of the chip U1 and the resistor R11.
  4. 4. An insulation monitor for a high voltage direct current device according to claim 3, wherein the measuring unit (1) further comprises a chip U2, a ninth pin of the chip U2 is electrically connected to the HV_Neg terminal, a third pin of the chip U2 is electrically connected to the switch_Neg terminal, and an eleventh pin of the chip U2 is electrically connected between the ninth pin of the chip U1 and the resistor R11 and outputs the InAMC _P signal.
  5. 5. The insulation monitor for a HVDC device according to claim 4, wherein the isolation differential unit (2) comprises a chip U3, wherein a sixth pin of the chip U3 receives the InAMC _P signal, the chip U3 is isolated, a tenth pin of the chip U3 outputs the Diff_N differential signal, and an eleventh pin of the chip U3 outputs the Diff_P differential signal.
  6. 6. The insulation monitor for the high-voltage direct-current equipment according to claim 5, wherein the differential-to-single-ended unit (3) comprises an operational amplifier U4, a resistor R22, a capacitor C3 and a capacitor C56, wherein an inverting input end of the operational amplifier U4 receives the Diff_N differential signal, a non-inverting input end of the operational amplifier U4 receives the Diff_P differential signal, the resistor R22 is electrically connected between the inverting input end and the output end of the operational amplifier U4, the capacitor C3 is connected in parallel with the resistor R22, the capacitor C56 is electrically connected between the output end of the operational amplifier U4 and a ground GND, and an output end of the operational amplifier U4 outputs the ADC_ Insu signal.
  7. 7. The insulation monitor for a hvdc device according to claim 1, wherein the voltage detection module comprises: The sampling differential unit (4) is used for sampling the voltage of the high-voltage loop, and calculating to obtain a diff_P_bat differential signal and a diff_N_bat differential signal after power supply isolation; and the voltage-to-single-ended unit (5) is used for receiving the Diff_P_bat differential signal and the Diff_N_bat differential signal, and obtaining an ADC_bat signal after calculation, thereby obtaining a high-voltage value.
  8. 8. The insulation monitor for the high-voltage direct-current equipment according to claim 7, wherein the sampling differential unit (4) comprises a chip U5 and a resistor R42, the resistor R42 is connected in series in a high-voltage loop, a sixth pin of the chip U5 is electrically connected to one end of the resistor R42, a seventh pin and an eighth pin of the chip U5 are electrically connected to the other end of the resistor R42 after being connected in parallel, the chip U5 is isolated, a tenth pin of the chip U5 outputs the diff_N_bat differential signal, and an eleventh pin of the chip U5 outputs the diff_P_bat differential signal.
  9. 9. The insulation monitor for a high voltage direct current device according to claim 8, wherein the voltage-to-single-ended unit (5) comprises an operational amplifier U6, a capacitor C57, a capacitor C15 and a resistor R35, wherein an inverting input terminal of the operational amplifier U6 receives the Diff_N_Bat differential signal, a non-inverting input terminal of the operational amplifier U6 receives the Diff_P_Bat differential signal, the resistor R35 is electrically connected between an inverting input terminal and an output terminal of the operational amplifier U6, the capacitor C15 is connected in parallel with the resistor R35, the capacitor C57 is electrically connected between an output terminal of the operational amplifier U6 and a ground GND, and an output terminal of the operational amplifier U6 outputs the ADC_Bat signal.

Description

Insulation monitor for high-voltage direct-current equipment Technical Field The application relates to the field of electric energy detection, in particular to an insulation monitor for high-voltage direct-current equipment. Background With the rise of new energy industry, high-voltage direct current charging piles and string photovoltaic systems are increasingly used, the direct current voltage can reach 800V-1000V or even higher, the insulation condition and voltage of a high-voltage bus are required to be monitored for guaranteeing the use safety, and once abnormal conditions occur, an insulation monitor can rapidly upload data to remind a user so as to guarantee the safety of related use and other people. At present, insulation detection equipment in the market is insufficient in electric gap between high voltage and low voltage, and when a large capacitor is arranged on a circuit, the measurement error is large. The measurement result may deviate greatly due to fluctuation of the measurement voltage source or interference, damage of the current sensor or sensitivity reduction. Disclosure of utility model In order to improve the problem, the application provides an insulation monitor for high-voltage direct-current equipment. The application provides an insulation monitor for high-voltage direct-current equipment, which adopts the following technical scheme: An insulation monitor for a high voltage direct current device, comprising: The resistance detection module is used for detecting the resistance value of the HV_pos end to the ground and the resistance value of the HV_neg end to the ground; And the voltage detection module is used for detecting the voltage of the high-voltage loop. By adopting the technical scheme, the detection of the resistance value and the voltage value is realized. Optionally, the resistance detection module includes: The measuring unit is used for measuring the voltage drop of the HV_pos end to the ground or the voltage drop of the HV_neg end to the ground to obtain InAMC _P signals; The isolation differential unit is used for receiving the InAMC _P signal, performing power supply isolation, and performing differential operation to obtain a diff_P differential signal and a diff_N differential signal; And the differential-to-single-ended unit is used for receiving the Diff_P differential signal and the Diff_N differential signal, and calculating to obtain an ADC_ Insu signal, thereby obtaining the resistance value of the HV_pos end to the ground or the resistance value of the HV_neg end to the ground. Through adopting above-mentioned technical scheme, carry out the isolation at the high-pressure side, produce differential signal at the low-pressure side, then change single-ended through the difference and realize the measurement of resistance value, carry out the isolation simultaneously and improve circuit security. Optionally, the measuring unit includes a chip U1 and a resistor R11, the eleventh pin of the chip U1 is electrically connected to the hv_pos terminal, the third pin of the chip U1 is electrically connected to the switch_pos terminal, the resistor R11 is serially connected to the ninth pin of the chip U1, and the InAMC _p signal is output between the ninth pin of the chip U1 and the resistor R11. By adopting the technical scheme, the HV_Pos terminal is sampled through the chip U1. Optionally, the measuring unit further includes a chip U2, a ninth pin of the chip U2 is electrically connected to the hv_neg terminal, a third pin of the chip U2 is electrically connected to the switch_neg terminal, and an eleventh pin of the chip U2 is electrically connected between the ninth pin of the chip U1 and the resistor R11, and outputs the InAMC _p signal. Through adopting above-mentioned technical scheme, through the chip U2 to HV_Neg end sampling, through dividing the monitoring of insulation resistance into two ways realization, can realize second level monitoring under the condition of great capacitance value, simultaneously again greatly reduced the cost. Optionally, the isolation differential unit includes a chip U3, a sixth pin of the chip U3 receives the InAMC _p signal, the chip U3 performs isolation, a tenth pin of the chip U3 outputs the diff_n differential signal, and an eleventh pin of the chip U3 outputs the diff_p differential signal. Through adopting above-mentioned technical scheme, realize the isolation of high pressure through chip U3, improved the security of circuit. Optionally, the differential-to-single-ended unit includes an operational amplifier U4, a resistor R22, a capacitor C3 and a capacitor C56, where an inverting input end of the operational amplifier U4 receives the diff_n differential signal, a non-inverting input end of the operational amplifier U4 receives the diff_p differential signal, the resistor R22 is electrically connected between the inverting input end and the output end of the operational amplifier U4, the capacitor C3 is connected