CN113514773A - Insulation monitoring system and monitoring method for standby instantaneous ground fault of direct-current power supply system - Google Patents
Insulation monitoring system and monitoring method for standby instantaneous ground fault of direct-current power supply system Download PDFInfo
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Abstract
The invention relates to the technical field of monitoring of direct-current power systems, in particular to a standby instantaneous earth fault insulation monitoring system and a standby instantaneous earth fault insulation monitoring method for a direct-current power system, wherein the standby instantaneous earth fault insulation monitoring system comprises a rear-end control device, a rear-end transmission device, an insulation monitoring host, a monitoring auxiliary machine and a line selection module; rear end controlling means and switch, switch pass through long distance transmission module or short distance transmission module and are connected with every insulation monitoring host computer, and insulation monitoring host computer and monitoring auxiliary engine one-to-one are connected, and every monitoring auxiliary engine is connected with a plurality of route selection modules, and every route selection module is connected with a plurality of current induction module. The method and the device realize real-time monitoring, judgment and positioning of the insulation fault of the direct-current power supply system, can effectively judge and position the instantaneous earth fault (namely the unreliable earth fault), provide a basis for checking all insulation fault points of the direct-current system, shorten the existence time of the fault, improve the safety of the direct-current power supply system and ensure the safe and reliable operation of the power system.
Description
Technical Field
The invention relates to the technical field of monitoring of direct-current power systems, in particular to a system and a method for monitoring standby instantaneous ground fault insulation of a direct-current power system.
Background
The direct current system is a power supply system of secondary equipment of the transformer substation, the direct current system network of the transformer substation is huge, and the direct current power supply system is designed into an ungrounded system, so that the occurrence of protection misoperation or operation failure accidents caused by the fact that a ground fault forms a wrong loop is avoided. The existing insulation monitoring device and the grounding finder of the running direct-current power supply system aim at permanent grounding faults, and the existing equipment cannot effectively monitor and find the existing equipment due to the short existence time of the grounding faults, thereby bringing great trouble to power production maintenance personnel.
Disclosure of Invention
The invention provides a standby instantaneous ground fault insulation monitoring system and a standby instantaneous ground fault insulation monitoring method for a direct current power supply system, overcomes the defects of the prior art, and can effectively solve the problem that the existing fault monitoring of the direct current power supply system cannot monitor the unreliable ground fault due to the ground fault, namely the instantaneous fault.
One of the technical schemes of the invention is realized by the following measures: a standby instantaneous earth fault insulation monitoring system of a direct current power supply system comprises a rear end control device, a rear end transmission device, a plurality of insulation monitoring main machines, a plurality of monitoring auxiliary machines, a plurality of line selection modules and a plurality of current induction modules; the back-end transmission device comprises a switch, a long-distance transmission module or a short-distance transmission module; rear end controlling means and switch, switch pass through long distance transmission module or short distance transmission module and are connected with every insulation monitoring host computer, and insulation monitoring host computer and monitoring auxiliary engine one-to-one are connected, and every monitoring auxiliary engine is connected with a plurality of route selection modules, and every route selection module is connected with a plurality of current induction module.
The following is further optimization or/and improvement of the technical scheme of the invention:
the insulation monitoring host comprises a host general control unit, a voltage acquisition unit, a bus resistance adjusting unit, a host communication display unit, an alarm unit and a host power supply unit, wherein the host general control unit is respectively connected with the voltage acquisition unit, the bus resistance adjusting unit, the alarm unit and the host communication display unit, and the host power supply unit supplies power for the insulation monitoring host.
The host master control unit comprises a host master control module and a host storage module, and the host master control module is respectively connected with the voltage acquisition unit, the bus resistance adjustment unit, the host communication display unit, the host power supply unit and the host storage module; the voltage acquisition unit comprises a voltage division circuit, a linear optocoupler and an amplification filter circuit, wherein the voltage division circuit, the linear optocoupler and the amplification filter circuit are sequentially connected; and the host communication display unit comprises a host communication module and a host display module, and the host communication module and the host display module are both connected with the host master control unit.
The monitoring auxiliary machine comprises an auxiliary machine main control unit, an auxiliary machine communication display unit, an auxiliary machine storage unit and an auxiliary machine power supply unit, wherein the auxiliary machine main control unit is respectively connected with the auxiliary machine storage unit and the auxiliary machine communication display unit, and the auxiliary machine power supply unit supplies power for the monitoring auxiliary machine.
The line selection module comprises a line selection master control unit, a current acquisition unit, a line selection communication unit and a line selection power supply unit, wherein the line selection master control unit is respectively connected with the current acquisition unit and the line selection communication unit, and the line selection power supply unit supplies power to the line selection module.
The current acquisition unit comprises a first amplifying circuit and a second amplifying circuit, and the first amplifying circuit is connected with the second amplifying circuit; and the line selection master control unit comprises a line selection master control module, a line selection storage module and a fault indication module, and the line selection storage module and the fault indication module are connected with the line selection master control unit.
The second technical scheme of the invention is realized by the following measures: a method for monitoring insulation of standby instantaneous earth fault of a direct current power supply system comprises the following steps:
the rear-end control device selects the insulation monitoring host through the rear-end transmission device;
the insulation monitoring host collects real-time voltage signals of the direct-current bus to ground, and starts a corresponding line selection module to collect branch current signals in real time through the monitoring auxiliary machine;
the insulation monitoring host continuously judges whether the real-time voltage signal of the direct-current bus line to the ground is normal, and controls the line selection module to select lines and judges whether the current signals of each branch circuit are normal in response to the insulation monitoring host judging that the voltage signal of the direct-current bus line to the ground is continuously abnormal;
the insulation monitoring host continuously judges whether the voltage signal of the real-time direct current bus to the ground is normal or not, if not, the ground fault location is completed, the line selection module displays the line selection result, if so, the instantaneous ground fault is determined, and the insulation monitoring host determines the instantaneous ground branch according to the return information of the monitoring auxiliary machine and the line selection module.
The following is further optimization or/and improvement of the technical scheme of the invention:
the above-mentioned completion ground fault location and instantaneous ground fault location further include:
the insulation monitoring host judges whether the voltage signal of the real-time direct current bus to the ground is normal;
if not, recording waves, determining a corresponding insulation resistance, and simultaneously judging whether the voltage signal of the direct current bus to the ground is abnormal or not;
responding, displaying the insulation resistance obtained by calculation, controlling the line selection module to select lines, judging whether current signals of each branch are normal by the line selection module, continuously judging whether voltage signals of a real-time direct-current bus line to a ground are normal by the insulation monitoring host, determining an instantaneous ground fault if the voltage signals of the real-time direct-current bus line to the ground are normal by the insulation monitoring host, and determining an instantaneous ground branch by the insulation monitoring host according to return information of the monitoring auxiliary machine and the line selection module;
and determining an instantaneous ground fault in response to the insulation monitoring host judging that the voltage signal of the direct-current bus line to the ground disappears abnormally, determining an instantaneous ground branch in the insulation monitoring host according to the return information of the monitoring auxiliary machine and the line selection module, completing the positioning of the ground fault in response to the insulation monitoring host judging that the voltage signal of the direct-current bus line to the ground is abnormal, and displaying a line selection result and recording waves by the line selection module.
The invention has simple structure and convenient use, realizes real-time monitoring, judgment and positioning of the insulation fault of the direct current power supply system by matching the rear-end control device, the rear-end transmission device, the insulation monitoring host, the monitoring auxiliary machine, the line selection module and the current induction module, can effectively judge and position the instantaneous ground fault (namely the unreliable ground fault), provides a basis for the investigation of all insulation fault points of the direct current system, shortens the existence time of the fault, improves the safety of the direct current power supply system, and ensures the safe and reliable operation of the power system.
Drawings
Fig. 1 is a schematic circuit diagram of embodiment 1 of the present invention.
Fig. 2 is a schematic circuit diagram of an insulation monitoring host according to embodiment 2 of the present invention.
Fig. 3 is a schematic circuit diagram of an isolated power supply module according to an embodiment of the present invention.
Fig. 4 is a schematic circuit structure diagram of a second power conversion output module according to an embodiment of the present invention.
Fig. 5 is a schematic circuit structure diagram of a voltage acquisition unit 2 in the embodiment of the present invention.
Fig. 6 is a schematic circuit diagram of a host memory module in embodiment 2 of the present invention.
Fig. 7 is a schematic circuit structure diagram of a 485 communication circuit in the embodiment of the present invention.
Fig. 8 is a schematic circuit diagram of a network communication interface circuit according to an embodiment of the present invention.
Fig. 9 is a schematic circuit diagram of a host display module according to an embodiment of the invention.
Fig. 10 is a schematic diagram of a monitoring auxiliary circuit according to embodiment 3 of the present invention.
Fig. 11 is a schematic circuit diagram of a line selection module according to embodiment 4 of the present invention.
Fig. 12 is a schematic circuit structure diagram of a current collection unit in embodiment 4 of the present invention.
FIG. 13 is a schematic flow chart of the method of example 5 of the present invention.
Fig. 14 is a flowchart illustrating a method for locating a fault in embodiment 5 of the present invention.
Detailed Description
The present invention is not limited by the following examples, and specific embodiments may be determined according to the technical solutions and practical situations of the present invention.
The invention is further described with reference to the following examples and figures:
In the above technical solution, the back-end control device may be an upper computer, and the back-end transmission device includes a switch, a long-distance transmission module or a short-distance transmission module; the rear end controlling means is connected with the switch, and the switch passes through long distance transmission module or short distance transmission module and is connected with every insulation monitoring host computer, realizes the data transmission between rear end controlling means and the insulation monitoring host computer, and wherein long distance transmission module can be a plurality of optical fiber transceivers for remote data transmission, and short distance transmission module can be the cable for short distance data transmission.
In the technical scheme, the insulation monitoring host is connected with the monitoring auxiliary machine in a one-to-one manner, the monitoring auxiliary machine is connected with the line selection module in a one-to-many manner, the line selection module is connected with the current induction module in a one-to-many manner, and the current induction module can be a current transformer CT and is used for inducing a current signal of a direct current bus; the insulation monitoring host measures the high-speed operation state of the direct current bus to the ground voltage in real time, the line selection module is connected with the plurality of current induction modules when in use, collects current signals of the direct current bus induced by the current induction modules, and judges whether the current signals are abnormal or not; when the insulation monitoring host determines that the voltage of the direct current bus to ground is abnormal, the current judgment condition of the line selection module is inquired through the monitoring auxiliary machine, meanwhile, the voltage of the direct current bus to ground is continuously judged, if the voltage of the direct current bus to ground is still abnormal, a ground fault branch (namely the branch where the current sensing module corresponding to the abnormal current is located) is determined, and if the voltage of the direct current bus to ground is recovered to be normal, the branch is determined to be an instantaneous ground fault branch.
In conclusion, the direct-current power supply system insulation fault diagnosis device is simple in structure and convenient to use, real-time monitoring, judgment and positioning of the direct-current power supply system insulation faults are achieved through the cooperation of the rear-end control device, the rear-end transmission device, the insulation monitoring host, the monitoring auxiliary machine, the line selection module and the current induction module, instantaneous ground faults (namely unreliable ground faults) can be effectively judged and positioned, a basis is provided for the investigation of all insulation fault points of the direct-current power supply system, the fault existence time is shortened, the safety of the direct-current power supply system is improved, and the safe and reliable operation of the power system is guaranteed.
In the technical scheme, the main machine power supply unit supplies power to the insulation monitoring main machine; the host power supply unit can comprise a first power supply conversion output module, an isolation power supply module and a second power supply conversion output module, wherein the first power supply conversion output module is used for converting 110V/220VAC into required voltage, for example, converting 110V/220VAC into 5V (supplying power to a digital circuit and an analog circuit) and 24VDC (supplying power to a display and measurement part), and a Mingwei power supply module can be selected; because the voltage acquisition unit of the invention needs to isolate the power supply for high-voltage acquisition, an isolation power supply module is arranged, and the isolation power supply module can be realized by adopting a 0505 isolation power supply module of Jinsheng Yang power supply company, as shown in figure 3; because of the power supply requirements of the digital circuit parts such as the host computer master control unit and the like, the second power supply conversion output module is arranged for converting 5VDC into 3.3VDC, and the power supply conversion output module can be realized by adopting a power supply chip ASM1117, as shown in figure 4.
In the technical scheme, the bus resistance adjusting unit comprises a plurality of balance bridges, and each balance bridge is connected with the master control unit. The bus resistance adjusting unit comprises a plurality of balance bridges, and the master control unit controls the resistance of the direct current bus by controlling the resistance input of each balance bridge, so that the voltage adjustment of the direct current bus is realized.
In the above technical scheme, the alarm unit is the prior known technology, and can be the prior audible and visual alarm.
Based on the circuit structure of the insulation monitoring host, the corresponding working process is as follows:
firstly, the voltage acquisition unit is used for acquiring the voltage to ground of the direct-current bus in real time and sending the voltage to the master control unit for storage and analysis; then, the master control unit compares the voltage of the direct current bus to ground at a certain moment with a preset voltage value, judges whether the voltage is abnormal or not, responds to the abnormality, determines the insulation resistance according to the stored wave recording information (wave recording can be used for storing 1s data cached before the abnormality and 40s data after the abnormality to form a 41s data change trend), and continuously judges whether the voltage of the direct current bus to ground is abnormal or not, responds to the result, acquires a current signal abnormal result determined by the line selection module, simultaneously continuously judges whether the voltage is abnormal or not, responds to the result, determines a ground fault branch according to the current signal abnormal result, responds to the result, determines the branch corresponding to the current signal abnormal result to be an instantaneous ground fault, and completes monitoring of the non-ground fault of the direct current power supply system.
As shown in fig. 5, the voltage acquisition unit in embodiment 2 further includes a voltage division circuit, a linear optocoupler and an amplification filter circuit, and the voltage division circuit, the linear optocoupler and the amplification filter circuit are connected in sequence.
Among the above-mentioned technical scheme, voltage acquisition unit includes bleeder circuit, linear opto-coupler device and amplification filter circuit, and voltage at first carries out the partial pressure through bleeder circuit, and input voltage control needs in the linear opto-coupler device between 0V to 200mV after the partial pressure, and the voltage is through amplifying filter circuit amplification filtering again after the amplification of linear opto-coupler device, and the output maximum voltage is close AD's reference voltage, and voltage processing enters the main control unit of host computer and carries out AD sampling after accomplishing. Wherein, the linear optical coupler can adopt HCPL-7840 linear optical coupler, and the amplifying and filtering circuit can be realized by LM358 amplifier.
As shown in fig. 2, the host master control unit in embodiment 2 further includes a host master control module and a host storage module, and the host master control module is connected to the voltage acquisition unit, the bus resistance adjustment unit, the communication display unit, the power supply unit, and the host storage module respectively.
In the technical scheme, the host master control unit comprises a host master control module and a host storage module, wherein the host master control module can be an STM32F103ZET6 chip, and an STM32F103ZET6 chip is an ARM 32-bit Cortex-M3 CPU, and has the characteristics of high running speed, large storage capacity, low power consumption and a large number of various functional interfaces, and the fastest 72MHz working frequency is realized; 12 AD channels, 112 fast bidirectional I/O ports and 13 communication interfaces, including a USB2.0 full-speed interface and an SDIO interface. The host storage module can be an 8G memory core circuit, and stores information data obtained by the host main control module, and the specific circuit is shown in fig. 6.
As shown in fig. 2, in embodiment 2, the host communication display unit further includes a host communication module and a host display module, and both the host communication module and the host display module are connected to the host general control unit.
In the above technical solution, the host communication module may include a 485 communication circuit and a network communication interface circuit; the 485 communication circuit can be as shown in fig. 7, and includes a level conversion chip SN75LBC184, which converts the signal output by the master control unit into a 485 level signal, and a 4-bit connection terminal CON2 is also placed on the PCB board, so as to facilitate connection to the connection terminal provided in the invention; the network communication interface circuit may be as shown in fig. 8.
In the above technical solution, the host display module is a prior art, and specifically, as shown in fig. 9, a circuit U6 driven by an LCD is a TTL to 232 level chip, and an L1-bit 120R magnetic bead can effectively suppress high frequency interference, and meanwhile, the display module can adopt a 7-inch serial industrial touch screen for inputting and connecting to a circuit 232 for outputting.
In the technical scheme, the monitoring auxiliary machine comprises an auxiliary machine main control unit, an auxiliary machine communication display unit, an auxiliary machine storage unit and an auxiliary machine power supply unit, wherein the auxiliary machine power supply unit can convert 110V/220VAC into required voltage, for example, 110V/220VAC into 5V (for supplying power to a digital circuit and an analog circuit) and 24VDC (for supplying power to a display and measurement part), and a Mingwi power supply module can be selected; the auxiliary machine main control unit can be an STM32F103ZET6 chip, the STM32F103ZET6 chip is an ARM 32-bit Cortex-M3 CPU, and the auxiliary machine main control unit has the characteristics of high running speed, large storage capacity, low power consumption and a large number of various functional interfaces; the auxiliary machine communication display unit is used for transmitting current signals, judgment signals and the like acquired by the far-end line selection module to the insulation monitoring host, and transmitting control commands and the like of the insulation monitoring host to the corresponding line selection module; the auxiliary machine storage unit can be the same as the main machine storage module in structure, namely can be an 8G memory core circuit and stores information data obtained by the auxiliary machine main control unit.
As shown in fig. 10, the auxiliary communication display unit in embodiment 3 further includes an auxiliary communication module and an auxiliary display unit, and both the auxiliary communication module and the auxiliary display unit are connected to the auxiliary general control unit.
In the above technical solution, the auxiliary communication module may include a 485 communication circuit and a network communication interface circuit; the 485 communication circuit can be as shown in fig. 7, and includes a level conversion chip SN75LBC184, which converts the signal output by the master control unit into a 485 level signal, and a 4-bit connection terminal CON2 is also placed on the PCB board, so as to facilitate connection to the connection terminal provided in the invention; the network communication interface circuit may be as shown in fig. 8.
In the above technical solution, the auxiliary display module is a prior known technology, and may have the same structure as the main display module, and specifically, as shown in fig. 9, the circuit U6 driven by the LCD is a TTL to 232 level chip, and the L1-bit 120R magnetic bead can effectively suppress high frequency interference, and meanwhile, the display module may adopt a 7-inch serial industrial touch screen, and the touch screen input circuit 232 outputs the signal.
In the above technical solution, the line selection module includes a line selection master control unit, a current collection unit, a line selection communication unit and a line selection power supply unit, where the line selection power supply unit may include a first power conversion output module, an isolation power supply module and a second power conversion output module, where the first power conversion output module is configured to convert 110V/220VAC into a required voltage, for example, convert 110V/220VAC into 5V (for supplying power to a digital circuit and an analog circuit) and 24VDC (for supplying power to a display and measurement portion), where a bright power supply module may be selected; because the voltage acquisition unit of the invention needs to isolate the power supply for high-voltage acquisition, an isolation power supply module is arranged, and the isolation power supply module can be realized by adopting a 0505 isolation power supply module of Jinsheng Yang power supply company, as shown in figure 3; because of the power supply requirements of digital circuit parts such as a master control unit and the like, a second power supply conversion output module is arranged for converting 5VDC into 3.3VDC, and the power supply conversion output module can be realized by adopting a power supply chip ASM1117, as shown in figure 4 specifically; the current acquisition unit is used for connecting the current induction module and acquiring a corresponding real-time current signal; the line selection master control unit is used for judging whether the received current is abnormal or not, judging that a ground fault occurs if the received current is abnormal, and recording waves, so that line selection positioning of the ground fault is realized; the line selection communication unit can comprise a 485 communication circuit and a network communication interface circuit; the 485 communication circuit can be as shown in fig. 7, and includes a level conversion chip SN75LBC184, which converts the signal output by the master control unit into a 485 level signal, and a 4-bit connection terminal CON2 is also placed on the PCB board, so as to facilitate connection to the connection terminal provided in the invention; the network communication interface circuit may be as shown in fig. 8.
As shown in fig. 12, the current collecting unit in embodiment 4 further includes a first amplifying circuit and a second amplifying circuit, and the first amplifying circuit is connected to the second amplifying circuit.
In the technical scheme, after current is induced by CT and amplified by the first amplifying circuit and the second amplifying circuit in sequence, the AD conversion is carried out by the line selection master control unit.
As shown in fig. 11, the line selection master control unit in embodiment 4 further includes a line selection main control module, a line selection storage module, and a fault indication module, where the line selection storage module and the fault indication module are both connected to the line selection main control unit.
In the technical scheme, the line selection main control module is the prior known technology and can be an STM32F103ZET6 chip, and the STM32F103ZET6 chip is an ARM 32-bit Cortex-M3 CPU, and has the characteristics of high running speed, large storage capacity, low power consumption and numerous functional interfaces; the line selection storage module can have the same result as the host storage module and can be an 8G storage core circuit for storing information data obtained by the line selection main control module, and the specific circuit is shown in figure 6; the fault indication module may be a fault indicator light.
s101, selecting an insulation monitoring host by a rear-end control device through a rear-end transmission device;
step S102, an insulation monitoring host collects real-time voltage signals of a direct current bus to ground, and starts a corresponding line selection module to collect branch current signals in real time through a monitoring auxiliary machine;
step S103, the insulation monitoring host continuously judges whether the real-time direct current bus voltage-to-ground voltage signal is normal, and controls the line selection module to select a line and judge whether the current signal of each branch is normal in response to the insulation monitoring host judging that the direct current bus voltage-to-ground voltage signal is continuously abnormal;
and step S104, the insulation monitoring host continuously judges whether the voltage signal of the real-time direct current bus to the ground is normal, if not, the ground fault positioning is finished, the line selection module displays the line selection result, if so, the instantaneous ground fault is determined, and the insulation monitoring host determines the instantaneous ground branch according to the return information of the monitoring auxiliary machine and the line selection module.
The feedback information of the line selection module comprises a current signal, wave recording information and a judgment result which are acquired by the line selection module.
As shown in fig. 14, the implementation of ground fault location and instantaneous ground fault location in embodiment 5 further includes:
step S301, the insulation monitoring host judges whether a voltage signal to ground of the real-time direct-current bus is normal;
step S302, in response to the judgment, recording waves, determining a corresponding insulation resistance, and meanwhile judging whether the voltage signal of the direct current bus to the ground is abnormal or not;
step S303, in response to the judgment, the insulation resistance obtained by calculation is displayed, line selection of the line selection module is controlled, the line selection module judges whether current signals of each branch are normal, meanwhile, the insulation monitoring host continuously judges whether voltage signals of a real-time direct-current bus to ground are normal, in response to the judgment, an instantaneous ground fault is determined, and the insulation monitoring host determines an instantaneous ground branch according to return information of the monitoring auxiliary machine and the line selection module;
step S304, in response to the insulation monitoring host computer judging that the voltage signal of the direct current bus to the ground disappears abnormally, the insulation monitoring host computer determines an instantaneous ground fault, the insulation monitoring host computer determines an instantaneous ground branch circuit according to the return information of the monitoring auxiliary machine and the line selection module, in response to the insulation monitoring host computer judging that the voltage signal of the direct current bus to the ground is abnormal, the ground fault positioning is completed, and the line selection module displays a line selection result and carries out wave recording.
The wave recording can be stored into the 1s data cached before the transaction and the 40s data after the transaction to form a 41s data change trend.
The above technical features constitute the best embodiment of the present invention, which has strong adaptability and best implementation effect, and unnecessary technical features can be increased or decreased according to actual needs to meet the requirements of different situations.
Claims (10)
1. A standby instantaneous earth fault insulation monitoring system of a direct current power supply system is characterized by comprising a rear end control device, a rear end transmission device, a plurality of insulation monitoring main machines, a plurality of monitoring auxiliary machines, a plurality of line selection modules and a plurality of current induction modules; the back-end transmission device comprises a switch, a long-distance transmission module or a short-distance transmission module; rear end controlling means and switch, switch pass through long distance transmission module or short distance transmission module and are connected with every insulation monitoring host computer, and insulation monitoring host computer and monitoring auxiliary engine one-to-one are connected, and every monitoring auxiliary engine is connected with a plurality of route selection modules, and every route selection module is connected with a plurality of current induction module.
2. The direct current power supply system standby instantaneous ground fault insulation monitoring system of claim 1, wherein the insulation monitoring host comprises a host general control unit, a voltage acquisition unit, a bus resistance adjustment unit, a host communication display unit, an alarm unit and a host power supply unit, the host general control unit is respectively connected with the voltage acquisition unit, the bus resistance adjustment unit, the alarm unit and the host communication display unit, and the host power supply unit supplies power to the insulation monitoring host.
3. The insulation monitoring system for the instantaneous ground fault of the direct-current power supply system as claimed in claim 2, wherein the host master control unit comprises a host master control module and a host storage module, and the host master control module is respectively connected with the voltage acquisition unit, the bus resistance adjustment unit, the host communication display unit, the host power supply unit and the host storage module; the voltage acquisition unit comprises a voltage division circuit, a linear optocoupler and an amplification filter circuit, wherein the voltage division circuit, the linear optocoupler and the amplification filter circuit are sequentially connected; and the host communication display unit comprises a host communication module and a host display module, and the host communication module and the host display module are both connected with the host master control unit.
4. The direct-current power supply system standby instantaneous ground fault insulation monitoring system according to claim 1, 2 or 3, characterized in that the monitoring auxiliary machine comprises an auxiliary machine main control unit, an auxiliary machine communication display unit, an auxiliary machine storage unit and an auxiliary machine power supply unit, wherein the auxiliary machine main control unit is respectively connected with the auxiliary machine storage unit and the auxiliary machine communication display unit, and the auxiliary machine power supply unit supplies power to the monitoring auxiliary machine.
5. The insulation monitoring system for the instantaneous ground fault of the direct-current power supply system according to claim 1, 2 or 3, characterized in that the line selection module comprises a line selection master control unit, a current acquisition unit, a line selection communication unit and a line selection power supply unit, wherein the line selection master control unit is respectively connected with the current acquisition unit and the line selection communication unit, and the line selection power supply unit supplies power to the line selection module.
6. The system for monitoring insulation of instantaneous ground fault of DC power supply system as claimed in claim 4, wherein said line selection module comprises a line selection master control unit, a current collection unit, a line selection communication unit and a line selection power supply unit, the line selection master control unit is respectively connected with the current collection unit and the line selection communication unit, and the line selection power supply unit supplies power to the line selection module.
7. The system for monitoring the insulation of the direct current power supply system against the instantaneous ground fault according to claim 5, characterized in that the current acquisition unit comprises a first amplification circuit and a second amplification circuit, and the first amplification circuit is connected with the second amplification circuit; and the line selection master control unit comprises a line selection master control module, a line selection storage module and a fault indication module, and the line selection storage module and the fault indication module are connected with the line selection master control unit.
8. The system according to claim 6, wherein the current collection unit comprises a first amplification circuit and a second amplification circuit, the first amplification circuit is connected with the second amplification circuit; and the line selection master control unit comprises a line selection master control module, a line selection storage module and a fault indication module, and the line selection storage module and the fault indication module are connected with the line selection master control unit.
9. A standby instantaneous earth fault insulation monitoring method for a direct current power supply system is characterized by comprising the following steps:
the rear-end control device selects the insulation monitoring host through the rear-end transmission device;
the insulation monitoring host collects real-time voltage signals of the direct-current bus to ground, and starts a corresponding line selection module to collect branch current signals in real time through the monitoring auxiliary machine;
the insulation monitoring host continuously judges whether the real-time voltage signal of the direct-current bus line to the ground is normal, and controls the line selection module to select lines and judges whether the current signals of each branch circuit are normal in response to the insulation monitoring host judging that the voltage signal of the direct-current bus line to the ground is continuously abnormal;
the insulation monitoring host continuously judges whether the voltage signal of the real-time direct current bus to the ground is normal or not, if not, the ground fault location is completed, the line selection module displays the line selection result, if so, the instantaneous ground fault is determined, and the insulation monitoring host determines the instantaneous ground branch according to the return information of the monitoring auxiliary machine and the line selection module.
10. The dc power supply system standby instantaneous ground fault insulation monitoring method of claim 9, wherein said performing ground fault location and determining an instantaneous ground fault comprises:
the insulation monitoring host judges whether the voltage signal of the real-time direct current bus to the ground is normal;
if not, recording waves, determining a corresponding insulation resistance, and simultaneously judging whether the voltage signal of the direct current bus to the ground is abnormal or not;
responding, displaying the insulation resistance obtained by calculation, controlling the line selection module to select lines, judging whether the current signals of each branch are normal by the line selection module, and continuously judging whether the voltage signals of the real-time direct-current bus to the ground are normal by the insulation monitoring host; if not, determining an instantaneous grounding fault, and determining an instantaneous grounding branch by the insulation monitoring host according to the return information of the monitoring auxiliary machine and the line selection module;
and determining an instantaneous ground fault in response to the insulation monitoring host judging that the voltage signal of the direct-current bus line to the ground disappears abnormally, determining an instantaneous ground branch in the insulation monitoring host according to the return information of the monitoring auxiliary machine and the line selection module, completing the positioning of the ground fault in response to the insulation monitoring host judging that the voltage signal of the direct-current bus line to the ground is abnormal, and displaying a line selection result and recording waves by the line selection module.
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