Insulation detection equipment and insulation detection method

Abstract

The invention provides insulation detection equipment and an insulation detection method. The insulation detection equipment comprises a voltage acquisition unit, a calculation unit and at least two resistor units, for each resistor unit, the resistor unit is electrically connected with a grounding end and a target output line; the voltage acquisition unit is used for acquiring the positive bus-to-ground voltage, the negative bus-to-ground voltage and the zero line-to-ground voltage after the target resistor unit conducts the access between the target output line and the grounding end; the calculation unit is used for calculating a first current corresponding to the target output line based on the voltage corresponding to the target output line and the resistance value of the target resistance unit; based on the first current, the positive bus-to-ground voltage, the negative bus-to-ground voltage and the zero line-to-ground voltage, calculating a positive ground insulation resistance value, a negative ground insulation resistance value and a zero line-to-ground insulation resistance value, and judging whether the three-wire high-voltage direct-current system has an insulation fault or not; therefore, the insulation detection of the three-wire high-voltage direct current system is solved, and the safety and reliability of the system are improved.

Description

Technical Field

[0001] This invention relates to the field of insulation testing technology, and in particular to an insulation testing device and an insulation testing method. Background Technology

[0002] With the development of power systems, high-voltage direct current (HVDC) transmission technology has become the preferred solution for long-distance, high-power power transmission. A three-wire HVDC system typically includes a positive bus, a negative bus, and a neutral wire to improve transmission efficiency and system stability. However, the safety and reliability of the system largely depend on its insulation performance. Insulation failures can lead to power transmission interruptions, equipment damage, and even safety accidents.

[0003] In the existing technology, insulation testing equipment is mainly used for two-wire high-voltage DC systems. Insulation testing for three-wire high-voltage DC systems is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] This invention provides an insulation testing device and an insulation testing method to solve the insulation testing of a three-wire high-voltage direct current system.

[0005] In a first aspect, embodiments of the present invention provide an insulation detection device for use in a three-wire high-voltage direct current system. The insulation detection device includes a voltage acquisition unit, a calculation unit, and at least two resistance units.

[0006] For each resistor unit, the resistor unit is electrically connected to the ground terminal and the target output line of the three-wire high-voltage DC system, wherein the target output line includes at least one of a positive bus, a negative bus, and a neutral line;

[0007] The voltage acquisition unit is used to acquire the positive busbar to ground voltage, the negative busbar to ground voltage, and the neutral line to ground voltage after the target resistor unit conducts the path between the target output line and the grounding terminal.

[0008] The calculation unit is electrically connected to the voltage acquisition unit and is used to calculate the first current corresponding to the target output line based on the voltage corresponding to the target output line and the resistance value of the target resistor unit; calculate the positive to ground insulation resistance value, the negative to ground insulation resistance value, and the neutral to ground insulation resistance value based on the first current, the positive bus to ground voltage, the negative bus to ground voltage, and the neutral to ground voltage; and determine whether there is an insulation fault in the three-wire high-voltage DC system based on the positive to ground insulation resistance value, the negative to ground insulation resistance value, and the neutral to ground insulation resistance value.

[0009] In one possible implementation, the target output line includes one of the positive bus, the negative bus, and the neutral line;

[0010] The resistor unit includes a first switch and a first resistor subunit, wherein the first resistor subunit includes at least one first resistor;

[0011] The first end of the first resistor subunit is electrically connected to the target output line, and the second end of the first resistor subunit is electrically connected to the first end of the first switch.

[0012] The second terminal of the first switch is electrically connected to the ground terminal.

[0013] In one possible implementation, the target output line includes a first target output line and a second target output line, wherein the first target output line and the second target output line are any two of the positive bus, the negative bus, and the zero line, and the first target output line and the second target output line are not the same.

[0014] The resistor unit includes a second switch, a second resistor subunit, and a third resistor subunit. The second resistor subunit includes at least one second resistor, and the third resistor subunit includes at least one third resistor.

[0015] The first end of the second resistor subunit is electrically connected to the first target output line, and the second end of the second resistor subunit is electrically connected to the first end of the second switch.

[0016] The first end of the third resistor subunit is electrically connected to the second target output line, and the second end of the third resistor subunit is electrically connected to the first end of the second switch.

[0017] The second terminal of the second switch is electrically connected to the ground terminal.

[0018] In one possible implementation, the target output line includes the positive bus, the negative bus, and the neutral line;

[0019] The resistor unit includes a third switch, a fourth resistor subunit, a fifth resistor subunit, and a sixth resistor subunit. The fourth resistor subunit includes at least one fourth resistor, the fifth resistor subunit includes at least one fifth resistor, and the sixth resistor subunit includes at least one sixth resistor.

[0020] The first end of the fourth resistor subunit is electrically connected to the negative bus in the target output line, and the second end of the fourth resistor subunit is electrically connected to the first end of the third switch.

[0021] The first end of the fifth resistor subunit is connected to the neutral wire in the target output line; the second end of the fifth resistor subunit is electrically connected to the first end of the third switch.

[0022] The first end of the sixth resistor subunit is electrically connected to the positive bus in the target output line; the second end of the sixth resistor subunit is electrically connected to the first end of the third switch.

[0023] The second terminal of the third switch is electrically connected to the ground terminal.

[0024] In one possible implementation, the insulation detection device further includes a grounding resistance unit, which includes at least one grounding resistor;

[0025] One end of the grounding resistor is electrically connected to the grounding terminal and one output line of the three-wire high-voltage DC system, and the other end of the grounding resistor is electrically connected to the grounding terminal.

[0026] In one possible implementation, the computing unit is specifically used for:

[0027] The first current is obtained by calculating the first quotient of the voltage corresponding to the target output line and the resistance value of the target resistor unit;

[0028] Based on the first current, positive bus current, negative bus current, and neutral current, a first current equation, a second current equation, and a third current equation are generated, wherein the first current equation, the second current equation, and the third current equation are generated based on different target resistance units.

[0029] Based on the first current equation, the second current equation, and the third current equation, calculate the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral-to-ground insulation resistance value.

[0030] In one possible implementation, the computing unit is further specifically used for:

[0031] Calculate the second quotient of the voltage corresponding to the target output line and the resistance value of the grounding resistor unit to obtain the second current corresponding to the target output line;

[0032] Based on the first current, the second current, the positive bus current, the negative bus current, and the neutral current, a fourth current equation, a fifth current equation, and a sixth current equation are generated.

[0033] Based on the fourth, fifth, and sixth current equations, calculate the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral-to-ground insulation resistance value.

[0034] Secondly, this application provides an insulation testing method, applied to any of the insulation testing devices described in the first aspect, the method comprising:

[0035] After the target resistor unit connects the target output line and the grounding terminal, the positive bus voltage to ground, the negative bus voltage to ground, and the neutral voltage to ground are collected.

[0036] Based on the voltage corresponding to the target output line and the resistance value of the target resistor unit, calculate the first current corresponding to the target output line;

[0037] Based on the first current, the positive busbar to ground voltage, the negative busbar to ground voltage, and the neutral line to ground voltage, calculate the positive to ground insulation resistance value, the negative to ground insulation resistance value, and the neutral line to ground insulation resistance value;

[0038] Based on the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral-to-ground insulation resistance value, it is determined whether there is an insulation fault in the three-wire high-voltage direct current system.

[0039] In one possible implementation, calculating the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral-to-ground insulation resistance value based on the first current, the positive busbar-to-ground voltage, the negative busbar-to-ground voltage, and the neutral-to-ground voltage includes:

[0040] The first quotient of the voltage corresponding to the target output line and the resistance value of the target resistor unit is calculated as the first current;

[0041] Based on the first current, positive bus current, negative bus current, and neutral current, a first current equation, a second current equation, and a third current equation are generated, wherein the first current equation, the second current equation, and the third current equation are generated based on different target resistance units.

[0042] Based on the first current equation, the second current equation, and the third current equation, calculate the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral-to-ground insulation resistance value.

[0043] In one possible implementation, the method further includes:

[0044] Calculate the second quotient of the voltage corresponding to the target output line and the resistance value of the grounding resistor unit to obtain the second current corresponding to the target output line;

[0045] Based on the first current, the second current, the positive bus current, the negative bus current, and the neutral current, a fourth current equation, a fifth current equation, and a sixth current equation are generated.

[0046] Based on the fourth, fifth, and sixth current equations, calculate the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral-to-ground insulation resistance value.

[0047] The beneficial effects of this application are as follows:

[0048] This application provides an insulation testing device and an insulation testing method. The insulation testing device includes a voltage acquisition unit, a calculation unit, and at least two resistor units. For each resistor unit, the resistor unit is electrically connected to a grounding terminal and a target output line of a three-wire high-voltage direct current (HVDC) system. The voltage acquisition unit is used to acquire the positive busbar-to-ground voltage, negative busbar-to-ground voltage, and neutral wire-to-ground voltage after the target resistor unit conducts a path between the target output line and the grounding terminal. The calculation unit is used to calculate a first current corresponding to the target output line based on the voltage corresponding to the target output line and the resistance value of the target resistor unit. Based on the first current, the positive busbar-to-ground voltage, the negative busbar-to-ground voltage, and the neutral wire-to-ground voltage, the unit calculates the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral wire-to-ground insulation resistance value. Based on the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral wire-to-ground insulation resistance value, the unit determines whether an insulation fault exists in the three-wire HVDC system. The insulation testing device provided in this application can perform insulation testing on a three-wire HVDC system, thereby improving the safety and reliability of the three-wire HVDC system. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 A schematic diagram of a three-wire high-voltage direct current system provided for related technologies;

[0051] Figure 2 This is a schematic diagram of the structure of an insulation testing device provided in an embodiment of this application;

[0052] Figure 3 An equivalent circuit diagram of the insulation resistance to ground provided in an embodiment of this application;

[0053] Figure 4 A circuit diagram of a resistor unit provided in an embodiment of this application;

[0054] Figure 5 A circuit diagram of another resistor unit provided in an embodiment of this application;

[0055] Figure 6A circuit diagram of another resistor unit provided in an embodiment of this application;

[0056] Figure 7 A circuit diagram of another resistor unit provided in an embodiment of this application;

[0057] Figure 8 This is a schematic diagram of another resistor unit structure provided in an embodiment of this application;

[0058] Figure 9 A circuit diagram of another resistor unit provided in an embodiment of this application;

[0059] Figure 10 A circuit diagram of another resistor unit provided in an embodiment of this application;

[0060] Figure 11 This is a schematic diagram of another resistor unit structure provided in an embodiment of this application;

[0061] Figure 12 A circuit diagram of another resistor unit provided in an embodiment of this application;

[0062] Figure 13 A circuit diagram of another resistor unit provided in an embodiment of this application;

[0063] Figure 14 This is a schematic diagram of the structure of an insulation testing device provided in an embodiment of this application;

[0064] Figure 15 This is a circuit diagram of an insulation testing device provided in an embodiment of this application;

[0065] Figure 16 A circuit diagram of another insulation testing device provided in an embodiment of this application;

[0066] Figure 17 This is a schematic flowchart of an insulation testing method provided in an embodiment of this application. Detailed Implementation

[0067] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0068] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0069] like Figure 1 The diagram shown is a structural schematic of a three-wire high-voltage direct current (HVDC) system provided by related technologies. The three-wire HVDC system includes an HVDC power supply unit, a positive bus A, a neutral bus B, and a negative bus C. The neutral bus B can also be called the ground return line.

[0070] To address the insulation testing of three-wire high-voltage direct current systems, embodiments of this application provide an insulation testing device applicable to, for example... Figure 1 The three-wire high-voltage direct current system shown is as follows: Figure 2 The diagram shown is a structural schematic of an insulation testing device provided in an embodiment of this application. The insulation device includes a voltage acquisition unit 21, a calculation unit 22, and at least two resistance units 23.

[0071] For each resistor unit 23, the resistor unit 23 is electrically connected to the ground terminal and the target output line of the three-wire high-voltage DC system, wherein the target output line includes at least one of the positive bus A, the negative bus C and the neutral line B;

[0072] Voltage acquisition unit 21 is used to acquire the positive bus voltage to ground U after the target resistor unit has connected the target output line and the ground terminal. + The voltage between the negative busbar and ground, U-, and the voltage between the neutral line and ground, U0;

[0073] The calculation unit 22 is electrically connected to the voltage acquisition unit 21 and is used to calculate the first current I1 corresponding to the target output line based on the voltage corresponding to the target output line and the resistance value of the target resistor unit; and to calculate the first current I1 and the positive bus voltage to ground U based on the first current I1 and the voltage U of the positive bus to ground. + Calculate the insulation resistance value R between the negative busbar to ground voltage U- and the neutral line to ground voltage U0. e+ Negative insulation resistance value to ground R e- The insulation resistance value R of the neutral wire to ground e0 Based on the ground insulation resistance value R e+ Negative insulation resistance value to ground R e- The insulation resistance value R of the neutral wire to ground e0 To determine whether there is an insulation fault in the three-wire high-voltage DC system.

[0074] In this embodiment, for each resistor unit 23, the resistor unit 23 is electrically connected to the grounding terminal and the target output line of the three-wire high-voltage DC system; after the target resistor unit conducts the path between the target output line and the grounding terminal, the voltage acquisition unit 21 acquires the positive bus voltage to ground U. + The calculation unit 22 calculates the first current I1 corresponding to the target output line based on the voltage corresponding to the target output line and the resistance value of the target resistor unit; based on the first current I1 and the positive bus voltage U0, the calculation unit 22 calculates the first current I1 corresponding to the target output line; and calculates the first current I1 and the positive bus voltage U0. + Calculate the insulation resistance value R between the negative busbar to ground voltage U- and the neutral line to ground voltage U0. e+ Negative insulation resistance value to ground R e- The insulation resistance value R of the neutral wire to ground e0 Based on the calculated insulation resistance value R to ground e+ Negative insulation resistance value to ground R e- The insulation resistance value R of the neutral wire to ground e0 The insulation testing equipment provided in this application can perform insulation testing on a three-wire high-voltage direct current system, thereby improving the safety and reliability of the system. This allows for the determination of whether the three-wire high-voltage direct current system has an insulation fault.

[0075] like Figure 3 As shown, R + The insulation resistance to ground is R. + The resistance value is the insulation resistance value R to ground. e+ ;R - The negative insulation resistance to ground is R. - The resistance value is negative, and the insulation resistance value to ground is R. e- R0 is the insulation resistance between the neutral wire and ground. The resistance value of R0 is the insulation resistance value between the neutral wire and ground. e0 .

[0076] In specific implementation, the resistor unit includes a switch and at least one resistor subunit. The resistor subunit includes at least one resistor, which is connected in series or in parallel. The number of target output lines is the same as the number of resistor subunits. Since the target output lines include at least one of the positive bus, negative bus, and neutral line, that is, the maximum number of target output lines is 3, the number of resistor subunits can also be 3 or more. The structure of the resistor unit will be described in detail below.

[0077] In one embodiment, the target output line includes one of a positive bus A, a negative bus C, and a neutral line B;

[0078] Resistor unit 23 includes a first switch K1 and a first resistor subunit. The first resistor subunit includes at least one first resistor, which are connected in series or in parallel.

[0079] The first end of the first resistor subunit is electrically connected to the target output line, and the second end of the first resistor subunit is electrically connected to the first end of the first switch K1.

[0080] The second terminal of the first switch K1 is electrically connected to the ground terminal.

[0081] For example, such as Figure 4 The diagram shown is a circuit schematic of a resistor unit provided in an embodiment of this application. The insulation detection device includes two resistor units, namely resistor unit 231 and resistor unit 232. The target output line corresponding to resistor unit 231 is the negative bus line C, and the target output line corresponding to resistor unit 232 is the neutral line B.

[0082] Resistor unit 231 includes a first switch K11 and a first resistor subunit 2311. The first resistor subunit 2311 includes a first resistor R11. The first end of the first resistor R11 is electrically connected to the negative bus C. The second end of the first resistor R11 is electrically connected to the first end of the first switch K11. The second end of the first switch K11 is grounded.

[0083] The resistor unit 232 includes a first switch K21 and a first resistor subunit 2321. The first resistor subunit 2321 includes a first resistor R21. The first end of the first resistor R21 is electrically connected to the neutral line B. The second end of the first resistor R21 is electrically connected to the first end of the first switch K21. The second end of the first switch K21 is grounded.

[0084] Or for example, such as Figure 5 The diagram shown is a circuit diagram of another resistor unit provided in an embodiment of this application. The insulation detection device includes three resistor units, namely resistor unit 231, resistor unit 232 and resistor unit 233. The target output line corresponding to resistor unit 231 is the negative bus line C, the target output line corresponding to resistor unit 232 is the neutral line B, and the target output line corresponding to resistor unit 233 is the positive bus line A.

[0085] Resistor unit 231 includes a first switch K11 and a first resistor subunit 2311. The first resistor subunit 2311 includes a first resistor R11. The first end of the first resistor R11 is electrically connected to the negative bus C. The second end of the first resistor R11 is electrically connected to the first end of the first switch K11. The second end of the first switch K11 is grounded.

[0086] Resistor unit 232 includes a first switch K21 and a first resistor subunit 2321. The first resistor subunit 2321 includes a first resistor R21. The first end of the first resistor R21 is electrically connected to the neutral line B. The second end of the first resistor R21 is electrically connected to the first end of the first switch K21. The second end of the first switch K21 is grounded.

[0087] The resistor unit 233 includes a first switch K41 and a first resistor subunit 2331. The first resistor subunit 2331 includes a first resistor R31. The first end of the first resistor R31 is electrically connected to the positive bus A. The second end of the first resistor R31 is electrically connected to the first end of the first switch K31. The second end of the first switch K31 is grounded.

[0088] For example, such as Figure 6 The diagram shown is a circuit diagram of another resistor unit provided in an embodiment of this application. The insulation detection device includes three resistor units, namely resistor unit 231, resistor unit 232 and resistor unit 233. The target output line corresponding to resistor unit 231 is the negative bus line C, the target output line corresponding to resistor unit 232 is the neutral line B, and the target output line corresponding to resistor unit 233 is the positive bus line A.

[0089] The resistor unit 231 includes a first switch K11 and a first resistor subunit 2311. The first resistor subunit 2311 includes a first resistor R12 and a first resistor R13 connected in series. The first end of the first resistor R12 is electrically connected to the negative bus C, the second end of the first resistor R12 is electrically connected to the first end of the first resistor R13, the second end of the first resistor R13 is electrically connected to the first end of the first switch K11, and the second end of the first switch K11 is grounded.

[0090] Resistor unit 232 includes a first switch K21 and a first resistor subunit 2321. The first resistor subunit 2321 includes a first resistor R22 and a first resistor R23 connected in series. The first end of the first resistor R22 is electrically connected to the neutral line B. The second end of the first resistor R22 is electrically connected to the first end of the first resistor R23. The second end of the first resistor R23 is electrically connected to the first end of the first switch K21. The second end of the first switch K21 is grounded.

[0091] The resistor unit 233 includes a first switch K31 and a first resistor subunit 2331. The first resistor subunit 2331 includes a first resistor R32 and a first resistor R33 connected in series. The first end of the first resistor R32 is electrically connected to the positive bus A. The second end of the first resistor R32 is electrically connected to the first end of the first resistor R33. The second end of the first resistor R33 is electrically connected to the first end of the first switch K31. The second end of the first switch K31 is grounded.

[0092] For example, such as Figure 7The diagram shown is a circuit diagram of another resistor unit provided in an embodiment of this application. The insulation detection device includes three resistor units, namely resistor unit 231, resistor unit 232 and resistor unit 233. The target output line corresponding to resistor unit 231 is the negative bus line C, the target output line corresponding to resistor unit 232 is the neutral line B, and the target output line corresponding to resistor unit 233 is the positive bus line A.

[0093] The resistor unit 231 includes a first switch K11 and a first resistor subunit 2311. The first resistor subunit 2311 includes a first resistor R14 and a first resistor R15 connected in parallel. The first end of the first resistor R14 is electrically connected to the first end of the first resistor R15 and the negative bus C. The second end of the first resistor R14 is electrically connected to the second end of the first resistor R15 and the first switch K11. The second end of the first switch K11 is grounded.

[0094] Resistor unit 232 includes a first switch K21 and a first resistor subunit 2321. The first resistor subunit 2321 includes a first resistor R24 ​​and a first resistor R25 connected in parallel. The first end of the first resistor R24 ​​is electrically connected to the first end of the first resistor R25 and the neutral line B. The second end of the first resistor R24 ​​is electrically connected to the second end of the first resistor R25 and the first end of the first switch K21. The second end of the first switch K21 is grounded.

[0095] The resistor unit 233 includes a first switch K31 and a first resistor subunit 2331. The first resistor subunit 2331 includes a first resistor R34 and a first resistor R35 connected in parallel. The first end of the first resistor R34 is electrically connected to the first end of the first resistor R35 and the positive bus A. The second end of the first resistor R34 is electrically connected to the second end of the first resistor R35 and the first end of the first switch K31. The second end of the first switch K31 is grounded.

[0096] It should be noted that the number of resistor units, the number of first resistors in the first resistor subunit, and the connection method of the first resistors can be adjusted according to actual application requirements. In addition, the connection method of the first resistors in the first resistor subunit can include both series and parallel connections, in addition to the series and parallel connections illustrated above. This application embodiment does not limit this.

[0097] The above embodiments only provide examples of two and three resistor units. Of course, more than three resistor units can also be included, but these will not be illustrated here.

[0098] In this embodiment of the application, if the insulation detection device includes two or three resistance units, and each resistance unit includes a first resistance sub-unit, then the target output line corresponding to each resistance unit includes one of the positive busbar A, the negative busbar C, and the neutral line B, and the target output lines corresponding to each resistance unit are different.

[0099] When the insulation testing equipment includes two resistance units, refer to Figure 4 The target output line corresponding to resistor unit 231 is the negative bus line C. The target output line corresponding to resistor unit 231 can be the zero line B or the positive bus line A.

[0100] When the insulation testing equipment includes three resistance units, refer to Figure 5 The target output line corresponding to resistor unit 231 is the negative bus line C, the target output line corresponding to resistor unit 232 is the zero line B, and the target output line corresponding to resistor unit 233 is the positive bus line A.

[0101] In one embodiment, when the resistor unit includes two resistor sub-units, the target output line includes a first target output line and a second target output line. The first target output line and the second target output line are any two of the positive bus line A, the negative bus line B and the zero line C, and the first target output line and the second target output line are not the same.

[0102] like Figure 8 As shown, the resistor unit 23 includes a second switch K2, a second resistor subunit 41 and a third resistor subunit 42. The second resistor subunit 41 includes at least one second resistor, and the third resistor subunit 42 includes at least one third resistor.

[0103] The first end of the second resistor subunit 41 is electrically connected to the first target output line, and the second end of the second resistor subunit 41 is electrically connected to the first end of the second switch K2.

[0104] The first end of the third resistor subunit 42 is electrically connected to the second target output line, and the second end of the third resistor subunit 42 is electrically connected to the first end of the second switch K2.

[0105] The second terminal of the second switch K2 is electrically connected to the ground terminal.

[0106] In this embodiment of the application, the second resistor subunit 41 includes at least one second resistor. If the value includes one second resistor, then the first end of the second resistor is the first end of the second resistor subunit 41, and the second end of the second resistor is the second end of the second resistor subunit 41. If it includes at least two second resistors, then the at least two second resistors can be connected in series, or in parallel, or in a combination of series and parallel. This embodiment of the application does not limit this.

[0107] The structure of the third resistor subunit 42 can be referred to the structure of the second resistor subunit 41 described above, and will not be repeated here.

[0108] For example, such as Figure 9 The diagram shown is a circuit diagram of a resistor unit provided in an embodiment of this application. The insulation detection device includes three resistor units, namely resistor unit 234, resistor unit 235 and resistor unit 236. The target output lines corresponding to resistor unit 234 are negative bus line C and positive bus line A, the target output lines corresponding to resistor unit 235 are neutral line B and positive bus line A, and the target output lines corresponding to resistor unit 236 are negative bus line C and neutral line B.

[0109] Resistor unit 234 includes a second switch K41, a second resistor subunit 2341, and a third resistor subunit 2342. The second resistor subunit 2341 includes a second resistor R41, the first end of which is electrically connected to the negative bus C, and the second end of which is electrically connected to the first end of the second switch K41. The third resistor subunit 2342 includes a second resistor R42, the first end of which is electrically connected to the positive bus A, and the second end of which is electrically connected to the first end of the second switch K41. The second end of the second switch K41 is grounded.

[0110] Resistor unit 235 includes a second switch K51, a second resistor subunit 2351, and a third resistor subunit 2352. The second resistor subunit 2351 includes a second resistor R51, the first end of which is electrically connected to the neutral line B, and the second end of which is electrically connected to the first end of the second switch K51. The third resistor subunit 2352 includes a second resistor R52, the first end of which is electrically connected to the positive busbar A, and the second end of which is electrically connected to the first end of the second switch K51. The second end of the second switch K51 is grounded.

[0111] Resistor unit 236 includes a second switch K61, a second resistor subunit 2361, and a third resistor subunit 2362. The second resistor subunit 2361 includes a second resistor R61, the first end of which is electrically connected to the negative bus C, and the second end of which is electrically connected to the first end of the second switch K61. The third resistor subunit 2362 includes a second resistor R62, the first end of which is electrically connected to the neutral line B, and the second end of which is electrically connected to the first end of the second switch K61. The second end of the second switch K61 is grounded.

[0112] In another embodiment, the resistor unit includes a seventh resistor R7, such as... Figure 10As shown, the insulation testing device includes three resistance units: resistance unit 234, resistance unit 235, and resistance unit 236. The target output lines corresponding to resistance unit 234 are the negative busbar C and the positive busbar A; the target output lines corresponding to resistance unit 235 are the neutral line B and the positive busbar A; and the target output lines corresponding to resistance unit 236 are the negative busbar C and the neutral line B.

[0113] Resistor unit 234 includes a second switch K41, a second resistor subunit 2341, a third resistor subunit 2342, and a seventh resistor R17. The second resistor subunit 2341 includes a second resistor R41, the first end of which is electrically connected to the negative bus C, and the second end of which is electrically connected to the first end of the seventh resistor R17. The third resistor subunit 2342 includes a second resistor R42, the first end of which is electrically connected to the positive bus A, and the second end of which is electrically connected to the first end of the seventh resistor R17. The second end of the seventh resistor R17 is electrically connected to the first end of the second switch K41, and the second end of the second switch K41 is grounded.

[0114] Resistor unit 235 includes a second switch K51, a second resistor subunit 2351, a third resistor subunit 2352, and a seventh resistor R27. The second resistor subunit 2351 includes a second resistor R51, the first end of which is electrically connected to the neutral line B, and the second end of which is electrically connected to the first end of the seventh resistor R27. The third resistor subunit 2352 includes a second resistor R52, the first end of which is electrically connected to the positive busbar A, and the second end of which is electrically connected to the first end of the seventh resistor R27. The second end of the seventh resistor R27 is electrically connected to the first end of the second switch K51, and the second end of the second switch K51 is grounded.

[0115] Resistor unit 236 includes a second switch K61, a second resistor subunit 2361, a third resistor subunit 2362, and a seventh resistor R37. The second resistor subunit 2361 includes a second resistor R61, the first end of which is electrically connected to the negative bus C, and the second end of which is electrically connected to the first end of the seventh resistor R37. The third resistor subunit 2362 includes a second resistor R62, the first end of which is electrically connected to the neutral line B, and the second end of which is electrically connected to the first end of the seventh resistor R37. The second end of the seventh resistor R37 is connected to the first end of the second switch K61, and the second end of the second switch K61 is grounded.

[0116] It should be noted that the number of resistor units, the number of second resistors in the second resistor subunit and the connection method of the second resistors, and the number of third resistors in the third resistor subunit and the connection method of the third resistors can be adjusted according to actual application requirements. In addition, the connection methods of the second resistors in the second resistor subunit and the connection methods of the third resistors in the third resistor subunit include series connection, parallel connection, and may include both series connection and parallel connection. This application embodiment does not limit this.

[0117] The above embodiments only provide an example of three resistor units. Of course, it can also include two or more resistor units, but this will not be illustrated here.

[0118] In one embodiment, the target output line includes a positive bus A, a negative bus C, and a neutral line B;

[0119] like Figure 11 As shown, resistor unit 23 includes a third switch K3, a fourth resistor subunit 43, a fifth resistor subunit 44 and a sixth resistor subunit 45. The fourth resistor subunit 43 includes at least one fourth resistor, the fifth resistor subunit 44 includes at least one fifth resistor, and the sixth resistor subunit 45 includes at least one sixth resistor.

[0120] The first end of the fourth resistor subunit 43 is electrically connected to the negative bus C in the target output line, and the second end of the fourth resistor subunit 43 is electrically connected to the first end of the third switch K3.

[0121] The first terminal of the fifth resistor subunit 44 is electrically connected to the neutral line B in the target output line; the second terminal of the fifth resistor subunit 44 is electrically connected to the first terminal of the third switch K3.

[0122] The first end of the sixth resistor sub-unit 45 is electrically connected to the positive bus A in the target output line; the second end of the sixth resistor sub-unit 45 is electrically connected to the first end of the third switch K3.

[0123] The second terminal of the third switch K3 is electrically connected to the ground terminal.

[0124] In this embodiment, the fourth resistor subunit 43 includes at least one second resistor. If the value includes a fourth resistor, then the first end of the fourth resistor is the first end of the fourth resistor subunit 41, and the second end of the fourth resistor is the second end of the fourth resistor subunit 41. If it includes at least two fourth resistors, then the at least two fourth resistors can be connected in series, in parallel, or in a combination of series and parallel. This embodiment does not limit this.

[0125] The structures of the fifth resistor subunit 44 and the sixth resistor subunit 25 can be referred to the structure of the fourth resistor subunit 43 described above, and will not be repeated here.

[0126] For example, such as Figure 12 The diagram shown is a circuit schematic of another resistor unit provided in an embodiment of this application. Figure 13 As shown, the insulation testing equipment includes three resistance units, namely resistance unit 237, resistance unit 238 and resistance unit 239, wherein the target output lines of the three resistance units are negative busbar C, neutral line B and positive busbar A;

[0127] The resistor unit 237 includes a fourth resistor subunit 2371, a fifth resistor subunit 2372, a sixth sub-resistor unit 2373 and a third switch K71. The fourth resistor subunit 2371 includes a fourth resistor R71, the fifth resistor subunit 2372 includes a fourth resistor R72, and the sixth sub-resistor unit 2373 includes a fourth resistor R73.

[0128] The first end of the fourth resistor R71 is electrically connected to the negative bus C, the first end of the fourth resistor R72 is electrically connected to the neutral line B, the first end of the fourth resistor R73 is electrically connected to the positive bus A, and the second ends of the fourth resistors R71, R72, and R73 are all electrically connected to the first end of the third switch K71. The second end of the third switch K71 is grounded.

[0129] The resistor unit 238 includes a fourth resistor subunit 2381, a fifth resistor subunit 2382, a sixth sub-resistor unit 2383, and a third switch K81. The fourth resistor subunit 2381 includes a fourth resistor R81, the fifth resistor subunit 2382 includes a fourth resistor R82, and the sixth sub-resistor unit 2383 includes a fourth resistor R83.

[0130] The first end of the fourth resistor R81 is electrically connected to the negative bus C, the first end of the fourth resistor R82 is electrically connected to the neutral line B, the first end of the fourth resistor R83 is electrically connected to the positive bus A, and the second ends of the fourth resistors R81, R82, and R83 are all electrically connected to the first end of the third switch K81. The second end of the third switch K81 is grounded.

[0131] The resistor unit 239 includes a fourth resistor subunit 2391, a fifth resistor subunit 2392, a sixth sub-resistor unit 2393, and a third switch K91. The fourth resistor subunit 2391 includes a fourth resistor R91, the fifth resistor subunit 2392 includes a fourth resistor R92, and the sixth sub-resistor unit 2393 includes a fourth resistor R93.

[0132] The first end of the fourth resistor R91 is electrically connected to the negative bus C, the first end of the fourth resistor R92 is electrically connected to the neutral line B, the first end of the fourth resistor R93 is electrically connected to the positive bus A, and the second ends of the fourth resistors R91, R92, and R93 are all electrically connected to the first end of the third switch K91. The second end of the third switch K91 is grounded.

[0133] In another embodiment, resistor unit 23 further includes an eighth resistor;

[0134] The insulation testing equipment includes three resistance units, namely resistance unit 237, resistance unit 238 and resistance unit 239, wherein the target output lines of the three resistance units are negative busbar C, neutral line B and positive busbar A;

[0135] The resistor unit 237 includes a fourth resistor subunit 2371, a fifth resistor subunit 2372, a sixth sub-resistor unit 2373, a third switch K71, and an eighth resistor R18. The fourth resistor subunit 2371 includes a fourth resistor R71, the fifth resistor subunit 2372 includes a fourth resistor R72, and the sixth sub-resistor unit 2373 includes a fourth resistor R73.

[0136] The first end of the fourth resistor R71 is electrically connected to the negative bus C, the first end of the fourth resistor R72 is electrically connected to the neutral line B, the first end of the fourth resistor R73 is electrically connected to the positive bus A, the second ends of the fourth resistor R71, the second ends of the fourth resistor R72, and the second ends of the fourth resistor R73 are all electrically connected to the first end of the eighth resistor R18, the second end of the eighth resistor R18 is electrically connected to the first end of the third switch K71, and the second end of the third switch K71 is grounded.

[0137] The resistor unit 238 includes a fourth resistor subunit 2381, a fifth resistor subunit 2382, a sixth sub-resistor unit 2383, a third switch K81, and an eighth resistor R28. The fourth resistor subunit 2381 includes a fourth resistor R81, the fifth resistor subunit 2382 includes a fourth resistor R82, and the sixth sub-resistor unit 2383 includes a fourth resistor R83.

[0138] The first end of the fourth resistor R81 is electrically connected to the negative bus C, the first end of the fourth resistor R82 is electrically connected to the neutral line B, the first end of the fourth resistor R83 is electrically connected to the positive bus A, the second ends of the fourth resistor R81, the second ends of the fourth resistor R82, and the second ends of the fourth resistor R83 are all electrically connected to the first end of the eighth resistor R28, the second end of the eighth resistor R28 is electrically connected to the first end of the third switch K81, and the second end of the third switch K81 is grounded.

[0139] The resistor unit 239 includes a fourth resistor subunit 2391, a fifth resistor subunit 2392, a sixth sub-resistor unit 2393, a third switch K91, and an eighth resistor R38. The fourth resistor subunit 2391 includes a fourth resistor R91, the fifth resistor subunit 2392 includes a fourth resistor R92, and the sixth sub-resistor unit 2393 includes a fourth resistor R93.

[0140] The first end of the fourth resistor R91 is electrically connected to the negative bus C, the first end of the fourth resistor R92 is electrically connected to the neutral line B, the first end of the fourth resistor R93 is electrically connected to the positive bus A, the second ends of the fourth resistor R91, the second ends of the fourth resistor R92, and the second ends of the fourth resistor R93 are all electrically connected to the first end of the eighth resistor R38, the second end of the eighth resistor R38 is electrically connected to the first end of the third switch K91, and the second end of the third switch K91 is grounded.

[0141] In one embodiment, such as Figure 14 The diagram shown is a structural schematic of another insulation testing device provided in this application embodiment. The insulation testing device further includes a grounding resistance unit 24, which includes at least one grounding resistor.

[0142] One end of the grounding resistor is electrically connected to the grounding terminal and one output line of the three-wire high-voltage DC system, and the other end of the grounding resistor is electrically connected to the grounding terminal.

[0143] In this embodiment of the application, the output line includes any one of the following: positive busbar A, neutral busbar B, and negative busbar C. For example, as... Figure 15 As shown, the grounding resistor unit 24 includes grounding resistor R241, grounding resistor R242 and grounding resistor R243;

[0144] The first end of the grounding resistor R241 is electrically connected to the positive busbar A, and the second end of the grounding resistor R241 is electrically connected to the grounding terminal.

[0145] The first end of the grounding resistor R242 is electrically connected to the neutral wire B, and the second end of the grounding resistor R242 is electrically connected to the grounding terminal.

[0146] The first end of the grounding resistor R243 is electrically connected to the negative busbar C, and the second end of the grounding resistor R243 is electrically connected to the grounding terminal.

[0147] It should be noted that the number of grounding resistors can be adjusted according to actual application requirements.

[0148] In one embodiment, the target output lines in the resistor unit can be different, such as Figure 16As shown, the grounding resistor unit includes a grounding resistor R241. In resistor unit 237, the second resistor subunit includes a second resistor R71 and the third resistor subunit includes a third resistor R72. The target output line of the second resistor R71 is the negative bus line C, and the target output line of the third resistor R72 is the positive bus line A. In resistor unit 238, the first resistor subunit includes a first resistor R81, and the target output line of the first resistor R81 is the neutral line B. In resistor unit 239, the second resistor subunit includes a second resistor R91 and the third resistor subunit includes a third resistor R92. The target output line of the second resistor R91 is the negative bus line C, and the target output line of the third resistor R92 is the positive bus line A.

[0149] The above describes the resistance unit and grounding resistance unit in the insulation testing equipment. In one embodiment, after the target resistance unit connects the target output line and the grounding terminal, the voltage acquisition unit 21 acquires the positive busbar-to-ground voltage U. + The calculation unit 22 calculates the first current I1 corresponding to the target output line based on the voltage corresponding to the target output line and the resistance value of the target resistor unit, given the negative bus-to-ground voltage U- and the neutral line-to-ground voltage U0. Based on the first current I1 and the positive bus-to-ground voltage U0, the calculation unit 22 calculates the first current I1 corresponding to the target output line. + Calculate the insulation resistance value R to ground based on the negative line-to-ground voltage U- and the neutral line-to-ground voltage U0. e+ Negative insulation resistance value to ground R e- The insulation resistance value R of the neutral wire to ground e0 .

[0150] In a specific embodiment, the calculation unit 22 calculates the first quotient of the voltage corresponding to the target output line and the resistance value of the target resistor unit to obtain the first current I1;

[0151] Based on the first current I1 and the positive bus current I + The negative bus current I- and the neutral current I0 are used to generate the first current equation, the second current equation, and the third current equation, which are generated based on different target resistance units.

[0152] Specifically, the positive bus current I + The positive busbar A is represented by the quotient of its insulation resistance to ground; the negative busbar current I- is represented by the quotient of its insulation resistance to ground; and the neutral wire current I0 is represented by the quotient of its insulation resistance to ground.

[0153] Based on the first current equation, the second current equation, and the third current equation, calculate the insulation resistance value R between the conductor and ground. e+ Negative insulation resistance value to ground R e- The insulation resistance value R of the neutral wire to ground e0 .

[0154] For example, refer to Figure 5 In this circuit, when the first switch K11 is closed, the target resistor unit is resistor unit 231, and the target output line is the negative busbar C; the voltage acquisition unit 21 acquires the voltage U of the positive busbar to ground at this time. 1+ The voltage between the negative busbar and ground, U1-, and the voltage between the neutral line and ground, U 10 ;

[0155] Calculation unit 22 is used to calculate the first quotient of the negative bus voltage to ground U1- and the resistance value of the first resistor R11, and obtain the first current I. 11 ,Right now

[0156] Combining Kirchhoff's current law, based on the first current I 11 Positive bus current I + The negative bus current I- and the neutral current I0 generate the first current equation, namely...

[0157] When the first switch K21 is closed, the target resistor unit is resistor unit 232, the target output line is neutral line B, and the voltage acquisition unit 21 acquires the voltage U of the positive busbar to ground at this time. 2+ The voltage between the negative busbar and ground, U2-, and the voltage between the neutral line and ground, U 20 ,

[0158] Calculation unit 22 calculates the neutral-to-ground voltage U. 20 The first current I is obtained by dividing the first value of the resistor R121 by the first value of the first resistor. 12 ,Right now

[0159] Combining Kirchhoff's current law, based on the first current I 12 Positive bus current I + The negative bus current I- and the neutral current I0 generate the second current equation, namely...

[0160] When the first switch K31 is closed, the target resistor unit is resistor unit 233, the target output line is the positive busbar A, and the voltage acquisition unit 21 acquires the voltage U of the positive busbar to ground at this time. 3+ The voltage between the negative busbar and ground, U3-, and the voltage between the neutral line and ground, U 30 ,

[0161] Calculation unit 22 calculates the positive busbar-to-ground voltage U. 3+ The first current I is obtained by dividing the first value by the first value of the first resistor R131. 13 ,Right now

[0162] Combining Kirchhoff's current law, based on the first current I 13Positive bus current I + The negative bus current I- and the neutral current I0 generate the third current equation, namely...

[0163] Calculation unit 22 combines the first current equation, the second current equation, and the third current equation to calculate the insulation resistance value R to ground. e+ Negative insulation resistance value to ground R e- The insulation resistance value R of the neutral wire to ground e0 .

[0164] It should be noted that the number of times the first switch is closed each time includes at least one first switch.

[0165] In another embodiment, after the target resistor unit and the grounding resistor unit connect the target output line and the grounding terminal, the voltage acquisition unit 21 acquires the positive bus voltage to ground U. + The calculation unit 22 calculates the first current I1 and the second current I2 corresponding to the target output line based on the voltage corresponding to the target output line and the resistance value of the target resistor unit, and the voltage U- of the negative busbar to ground and the voltage U0 of the neutral line to ground. + Calculate the insulation resistance value R to ground based on the negative line-to-ground voltage U- and the neutral line-to-ground voltage U0. e+ Negative insulation resistance value to ground R e- The insulation resistance value R of the neutral wire to ground e0 .

[0166] In a specific implementation, the calculation unit 22 calculates the first quotient of the voltage corresponding to the target output line and the resistance value of the target resistor unit to obtain the first current I1, and calculates the second quotient of the voltage corresponding to the target output line and the resistance value of the grounding resistor unit to obtain the second current I2.

[0167] Based on the first current I1, the second current I2, and the positive bus current I + The negative bus current I- and the neutral current I0 are used to generate the fourth, fifth, and sixth current equations, which are generated based on different target resistance units.

[0168] Specifically, the positive bus current I + The positive busbar A is represented by the quotient of its insulation resistance to ground; the negative busbar current I- is represented by the quotient of its insulation resistance to ground; and the neutral wire current I0 is represented by the quotient of its insulation resistance to ground.

[0169] Based on the fourth, fifth, and sixth current equations, calculate the insulation resistance value R to ground. e+Negative insulation resistance value to ground R e- The insulation resistance value R of the neutral wire to ground e0 .

[0170] For example, such as Figure 15 The diagram shown is a circuit diagram of an insulation testing device provided in an embodiment of this application.

[0171] When the third switch K71 is closed, the target resistance unit includes grounding resistance unit 24 and resistance unit 237, and the target output line includes negative busbar C, neutral line B and positive busbar A; the voltage acquisition unit 21 acquires the voltage U of the positive busbar to ground at this time. 4+ The voltage between the negative busbar and ground, U4-, and the voltage between the neutral line and ground, U 40 ;

[0172] Calculation unit 22 is used to calculate the quotient of the negative bus voltage to ground U4- and the fourth resistor R71, as well as the neutral voltage to ground U 40 The quotient of the fifth resistor R72, and the positive bus voltage to ground U 4+ The quotient of the first current I is obtained by dividing the first current I by the value of the sixth resistor R73. 14 ,Right now

[0173] Calculation unit 22 is used to calculate the positive busbar-to-ground voltage U. 4+ The quotient of the grounding resistance R241, and the neutral-to-ground voltage U 40 The second current I is obtained by taking the quotient of the grounding resistance R242 and the quotient of the negative bus voltage to ground U4- and the grounding resistance R243. 21 ,Right now

[0174] Combining Kirchhoff's current law, based on the first current I 14 Second current I 21 Positive bus current I + The negative bus current I- and the neutral current I0 generate the fourth current equation, namely:

[0175]

[0176] When the third switch K81 is closed, the target resistance unit includes grounding resistance unit 24 and resistance unit 238, and the target output line includes negative busbar C, neutral line B and positive busbar A; the voltage acquisition unit 21 acquires the voltage U of the positive busbar to ground at this time. 5+ The voltage between the negative busbar and ground, U5-, and the voltage between the neutral line and ground, U 50 ;

[0177] Calculation unit 22 is used to calculate the quotient of the negative busbar-to-ground voltage U5- and the fourth resistor R81, as well as the neutral-to-ground voltage U. 50The quotient of the fifth resistor R82, and the positive bus voltage to ground U 5+ The quotient of the first current I is obtained by dividing the first current I by the value of the sixth resistor R83. 15 ,Right now

[0178] Calculation unit 22 is used to calculate the positive busbar-to-ground voltage U. 5+ The quotient of the grounding resistance R241, and the neutral-to-ground voltage U 50 The second current I is obtained by taking the quotient of the grounding resistance R242 and the quotient of the negative bus voltage to ground U5 and the grounding resistance R243. 22 ,Right now

[0179] Combining Kirchhoff's current law, based on the first current I 15 Second current I 22 Positive bus current I + The negative bus current I- and the neutral current I0 generate the fifth current equation, namely:

[0180]

[0181] When the third switch K91 is closed, the target resistance unit includes grounding resistance unit 24 and resistance unit 239, and the target output line includes negative busbar C, neutral line B and positive busbar A; the voltage acquisition unit 21 acquires the voltage U of the positive busbar to ground at this time. 6+ The voltage between the negative busbar and ground, U6-, and the voltage between the neutral line and ground, U 60 ;

[0182] Calculation unit 22 is used to calculate the quotient of the negative busbar-to-ground voltage U6- and the fourth resistor R91, as well as the neutral-to-ground voltage U. 60 The quotient of the fifth resistor R92, and the positive bus voltage to ground U 6+ The quotient of the first current I is obtained by dividing the first current I by the value of the sixth resistor R93. 16 ,Right now

[0183] Calculation unit 22 is used to calculate the positive busbar-to-ground voltage U. 6+ The quotient of the grounding resistance R241, and the neutral-to-ground voltage U 60 The second current I is obtained by taking the quotient of the grounding resistance R242 and the quotient of the negative bus voltage to ground U6 and the grounding resistance R243. 23 ,Right now

[0184] Combining Kirchhoff's current law, based on the first current I 16 Second current I 23 Positive bus current I +The negative bus current I- and the neutral current I0 generate the fifth current equation, namely:

[0185]

[0186] Calculation unit 22 combines the third, fourth, and fifth current equations to calculate the insulation resistance value R to ground. e+ Negative insulation resistance value to ground R e- The insulation resistance value R of the neutral wire to ground e0 .

[0187] It should be noted that the number of times the third switch is closed each time includes at least one third switch.

[0188] Based on the insulation resistance value R to ground e+ Negative insulation resistance value to ground R e- The insulation resistance value R of the neutral wire to ground e0 An insulation fault has been confirmed. Specifically, when the insulation resistance value to ground is R... e+ Negative insulation resistance value to ground R e- The insulation resistance value R of the neutral wire to ground e0 If any one of the values ​​is less than the preset insulation resistance value, it is determined that there is an insulation problem with the load resistance on the target output line.

[0189] Based on the same inventive concept, this embodiment of the invention also provides an insulation testing method, which is applied to any of the insulation testing devices described above. The implementation of the method can refer to the implementation of the insulation testing device, and repeated parts will not be described again.

[0190] like Figure 17 As shown, an insulation testing method provided in this application embodiment specifically includes the following steps:

[0191] S171: After the target resistor unit connects the target output line and the grounding terminal, the positive bus voltage to ground, the negative bus voltage to ground, and the neutral voltage to ground are collected.

[0192] S172: Calculate the first current corresponding to the target output line based on the voltage corresponding to the target output line and the resistance value of the target resistor unit;

[0193] S173: Based on the first current, the positive busbar to ground voltage, the negative busbar to ground voltage, and the neutral line to ground voltage, calculate the positive to ground insulation resistance value, the negative to ground insulation resistance value, and the neutral line to ground insulation resistance value;

[0194] S174: Based on the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral-to-ground insulation resistance value, determine whether there is an insulation fault in the three-wire high-voltage DC system.

[0195] In one optional implementation, the step of calculating the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral-to-ground insulation resistance value based on the first current, the positive busbar-to-ground voltage, the negative busbar-to-ground voltage, and the neutral-to-ground voltage includes:

[0196] The first quotient of the voltage corresponding to the target output line and the resistance value of the target resistor unit is calculated as the first current;

[0197] Based on the first current, positive bus current, negative bus current, and neutral current, a first current equation, a second current equation, and a third current equation are generated, wherein the first current equation, the second current equation, and the third current equation are generated based on different target resistance units.

[0198] Based on the first current equation, the second current equation, and the third current equation, calculate the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral-to-ground insulation resistance value.

[0199] In one optional implementation, the method further includes:

[0200] Calculate the second quotient of the voltage corresponding to the target output line and the resistance value of the grounding resistor unit to obtain the second current corresponding to the target output line;

[0201] Based on the first current, the second current, the positive bus current, the negative bus current, and the neutral current, a fourth current equation, a fifth current equation, and a sixth current equation are generated.

[0202] Based on the fourth, fifth, and sixth current equations, calculate the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral-to-ground insulation resistance value.

[0203] This application provides an insulation testing device and an insulation testing method. The insulation testing device includes a voltage acquisition unit, a calculation unit, and at least two resistor units. For each resistor unit, the resistor unit is electrically connected to a grounding terminal and a target output line of a three-wire high-voltage direct current (HVDC) system. The voltage acquisition unit is used to acquire the positive busbar-to-ground voltage, negative busbar-to-ground voltage, and neutral wire-to-ground voltage after the target resistor unit conducts a path between the target output line and the grounding terminal. The calculation unit is used to calculate a first current corresponding to the target output line based on the voltage corresponding to the target output line and the resistance value of the target resistor unit. Based on the first current, the positive busbar-to-ground voltage, the negative busbar-to-ground voltage, and the neutral wire-to-ground voltage, the unit calculates the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral wire-to-ground insulation resistance value. Based on the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral wire-to-ground insulation resistance value, the unit determines whether an insulation fault exists in the three-wire HVDC system. The insulation testing device provided in this application can perform insulation testing on a three-wire HVDC system, thereby improving the safety and reliability of the three-wire HVDC system.

[0204] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0205] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0206] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0207] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0208] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. An insulation testing device, characterized in that, Applied to a three-wire high-voltage direct current system, the insulation detection device includes a voltage acquisition unit, a calculation unit, and at least two resistance units; For each resistor unit, the resistor unit is electrically connected to the ground terminal and the target output line of the three-wire high-voltage DC system, wherein the target output line includes at least one of a positive bus, a negative bus, and a neutral line; The voltage acquisition unit is used to acquire the positive busbar to ground voltage, the negative busbar to ground voltage, and the neutral line to ground voltage after the target resistor unit conducts the path between the target output line and the grounding terminal. The calculation unit is electrically connected to the voltage acquisition unit and is used to calculate the first current corresponding to the target output line based on the voltage corresponding to the target output line and the resistance value of the target resistor unit; calculate the positive to ground insulation resistance value, the negative to ground insulation resistance value, and the neutral to ground insulation resistance value based on the first current, the positive bus to ground voltage, the negative bus to ground voltage, and the neutral to ground voltage; and determine whether there is an insulation fault in the three-wire high-voltage DC system based on the positive to ground insulation resistance value, the negative to ground insulation resistance value, and the neutral to ground insulation resistance value.

2. The device according to claim 1, characterized in that, The target output line includes one of the positive bus, the negative bus, and the zero line; The resistor unit includes a first switch and a first resistor subunit, wherein the first resistor subunit includes at least one first resistor; The first end of the first resistor subunit is electrically connected to the target output line, and the second end of the first resistor subunit is electrically connected to the first end of the first switch. The second terminal of the first switch is electrically connected to the ground terminal.

3. The device according to claim 2, characterized in that, The target output line includes a first target output line and a second target output line, wherein the first target output line and the second target output line are any two of the positive bus, the negative bus, and the zero line, and the first target output line and the second target output line are not the same; The resistor unit includes a second switch, a second resistor subunit, and a third resistor subunit. The second resistor subunit includes at least one second resistor, and the third resistor subunit includes at least one third resistor. The first end of the second resistor subunit is electrically connected to the first target output line, and the second end of the second resistor subunit is electrically connected to the first end of the second switch. The first end of the third resistor subunit is electrically connected to the second target output line, and the second end of the third resistor subunit is electrically connected to the first end of the second switch. The second terminal of the second switch is electrically connected to the ground terminal.

4. The device as described in claim 3, characterized in that, The target output line includes the positive bus, the negative bus, and the neutral line; The resistor unit includes a third switch, a fourth resistor subunit, a fifth resistor subunit, and a sixth resistor subunit. The fourth resistor subunit includes at least one fourth resistor, the fifth resistor subunit includes at least one fifth resistor, and the sixth resistor subunit includes at least one sixth resistor. The first end of the fourth resistor subunit is electrically connected to the negative bus in the target output line, and the second end of the fourth resistor subunit is electrically connected to the first end of the third switch. The first end of the fifth resistor subunit is connected to the neutral wire in the target output line; the second end of the fifth resistor subunit is electrically connected to the first end of the third switch. The first end of the sixth resistor subunit is electrically connected to the positive bus in the target output line; the second end of the sixth resistor subunit is electrically connected to the first end of the third switch. The second terminal of the third switch is electrically connected to the ground terminal.

5. The device according to any one of claims 1, characterized in that, The insulation testing equipment further includes a grounding resistance unit, which includes at least one grounding resistor. One end of the grounding resistor is electrically connected to the grounding terminal and one output line of the three-wire high-voltage DC system, and the other end of the grounding resistor is electrically connected to the grounding terminal.

6. The device according to any one of claims 1 to 5, characterized in that, The computing unit is specifically used for: The first current is obtained by calculating the first quotient of the voltage corresponding to the target output line and the resistance value of the target resistor unit; Based on the first current, positive bus current, negative bus current, and neutral current, a first current equation, a second current equation, and a third current equation are generated, wherein the first current equation, the second current equation, and the third current equation are generated based on different target resistance units. Based on the first current equation, the second current equation, and the third current equation, calculate the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral-to-ground insulation resistance value.

7. The device according to claim 6, characterized in that, The computing unit is also specifically used for: Calculate the second quotient of the voltage corresponding to the target output line and the resistance value of the grounding resistor unit to obtain the second current corresponding to the target output line; Based on the first current, the second current, the positive bus current, the negative bus current, and the neutral current, a fourth current equation, a fifth current equation, and a sixth current equation are generated. Based on the fourth, fifth, and sixth current equations, calculate the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral-to-ground insulation resistance value.

8. An insulation testing method, characterized in that, The method, applied to the insulation testing equipment as described in any one of claims 1 to 7, comprises: After the target resistor unit connects the target output line and the grounding terminal, the positive bus voltage to ground, the negative bus voltage to ground, and the neutral voltage to ground are collected. Based on the voltage corresponding to the target output line and the resistance value of the target resistor unit, calculate the first current corresponding to the target output line; Based on the first current, the positive busbar to ground voltage, the negative busbar to ground voltage, and the neutral line to ground voltage, calculate the positive to ground insulation resistance value, the negative to ground insulation resistance value, and the neutral line to ground insulation resistance value; Based on the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral-to-ground insulation resistance value, it is determined whether there is an insulation fault in the three-wire high-voltage DC system.

9. The method according to claim 8, characterized in that, The calculation of the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral-to-ground insulation resistance value based on the first current, the positive busbar-to-ground voltage, the negative busbar-to-ground voltage, and the neutral-to-ground voltage includes: The first quotient of the voltage corresponding to the target output line and the resistance value of the target resistor unit is calculated as the first current; Based on the first current, positive bus current, negative bus current, and neutral current, a first current equation, a second current equation, and a third current equation are generated, wherein the first current equation, the second current equation, and the third current equation are generated based on different target resistance units. Based on the first current equation, the second current equation, and the third current equation, calculate the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral-to-ground insulation resistance value.

10. The method according to claim 8, characterized in that, The method further includes: Calculate the second quotient of the voltage corresponding to the target output line and the resistance value of the grounding resistor unit to obtain the second current corresponding to the target output line; Based on the first current, the second current, the positive bus current, the negative bus current, and the neutral current, a fourth current equation, a fifth current equation, and a sixth current equation are generated. Based on the fourth, fifth, and sixth current equations, calculate the positive-to-ground insulation resistance value, the negative-to-ground insulation resistance value, and the neutral-to-ground insulation resistance value.

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