Distribution network insulation resistance testing device and testing method thereof

Abstract

The embodiment of the invention discloses a power distribution network insulation resistance testing device and a testing method thereof. The power distribution network insulation resistance testing device comprises a plurality of output channels; a test terminal; the channel switching module comprises a static contact, a moving contact and a driving mechanism, the moving contact is connected with the output channel, and the driving mechanism is used for driving the moving contact to move; the control module is used for acquiring the initial positions of the moving contacts corresponding to the different output channels, determining the target positions of the moving contacts in the corresponding output channels according to test requirements, and controlling the corresponding driving mechanisms to extend or retract along the linear direction according to the initial positions and the target positions; and the moving contact is electrically connected with the static contact corresponding to the target position. According to the invention, by adjusting the connection relationship between the plurality of output channels and the to-be-tested power distribution network, automatic testing of multiple groups of insulation resistors is realized, an automatic discharge function is introduced, the equipment and the tested object are protected, the operation process is simplified, and the testing efficiency and the testing safety are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power testing, and in particular to a power distribution network insulation resistance testing device and a testing method thereof. Background Art

[0002] The safe operation of the distribution network is crucial to the stability of the power system. Insulation resistance testing is an important means of evaluating the insulation performance of the distribution network, used to detect potential insulation faults and ensure the safe operation of the power system.

[0003] In the process of insulation resistance test of distribution network, for the insulation resistance test of three-phase line, it is necessary to measure not only the insulation resistance value between each phase, but also the insulation resistance value between each phase and ground; for the operation and maintenance test of transformer, it is also necessary to measure the insulation resistance between windings and between windings and ground. In actual operation, traditional insulation resistance testers can only measure one set of data at a time. Each measurement requires multiple wiring, starting measurement, recording data, discharging and removing wires. The whole process is cumbersome, time-consuming and inefficient.

[0004] Although the existing digital insulation tester has improved the test efficiency to a certain extent, it is still necessary to test the resistance of each circuit one by one for multiple groups of insulation resistance tests, record the data manually, and manually discharge each circuit after each group of tests. The operation process is time-consuming and prone to errors, and it is difficult to meet the needs of intelligent operation and maintenance. Summary of the invention

[0005] The present invention provides a power distribution network insulation resistance testing device and a testing method thereof. The device automatically completes the insulation resistance testing task by adjusting the connection relationship between multiple output channels and the power distribution network to be tested, thereby increasing the safety of the insulation tester and improving the testing efficiency of the insulation tester.

[0006] In the first aspect, an embodiment of the present invention provides a distribution network insulation resistance testing device, comprising: multiple output channels, the output channels are used to connect to the distribution network to be tested; test terminals, at least including: a high-voltage output positive terminal, a high-voltage output negative terminal and a discharge terminal; a channel switching module, which is arranged in a one-to-one correspondence with the output channels, the channel switching module includes a static contact, a moving contact and a driving mechanism, the static contact is connected to the test terminals in a one-to-one correspondence, the moving contact is connected to the output channel, and the driving mechanism is used to drive the moving contact to move in a straight line direction; a control module, which is connected to the control end of the driving mechanism, and is used to obtain the initial position of the moving contact corresponding to different output channels, determine the target position of the moving contact in the corresponding output channel according to the test requirements, and control the corresponding driving mechanism to extend or retract in a straight line direction according to the initial position and the target position, so that the moving contact is electrically connected to the static contact corresponding to the target position.

[0007] Optionally, the static contact includes a first conductive part and a first insulating sheath sleeved on the outer periphery of the first conductive part; the moving contact includes a second conductive part and a second insulating sheath sleeved on the outer periphery of the second conductive part; when the moving contact is connected to the static contact, the first conductive part and the second conductive part are in elastic interference contact; when the moving contact is not connected to the static contact, the minimum spacing distance between the first conductive part and the second conductive part is greater than a preset air insulation spacing; wherein, the preset air insulation spacing is calculated based on the insulation resistance of the distribution network to be tested.

[0008] Optionally, the first insulating sheath and the second insulating sheath are formed by using insulating material; the thickness of the insulating material is calculated based on the insulation resistance of the power distribution network to be tested.

[0009] Optionally, the first conductive portion includes two connecting pieces with conical cross sections; the second conductive portion includes two trapezoidal connecting pieces, and the trapezoidal upper and lower surfaces of the trapezoidal connecting pieces are arranged opposite to each other.

[0010] Optionally, the driving mechanism includes: an electric telescopic rod for fixing the moving contact; a push rod control circuit for controlling the extension movement of the electric telescopic rod when receiving a first control signal output by the control module; and controlling the retraction movement of the electric telescopic rod when receiving a second control signal output by the control module.

[0011] Optionally, the push rod control circuit includes: a drive motor, a forward drive branch and a reverse drive branch; the drive motor is meshed and connected with the electric telescopic rod; the forward drive branch is used to apply a forward voltage to the drive motor when receiving a first control signal, so that the drive motor rotates forward and drives the electric telescopic rod to extend; the reverse drive branch is used to apply a reverse voltage to the drive motor when receiving a second control signal, so that the drive motor reverses and drives the electric telescopic rod to retract.

[0012] Optionally, the discharge end includes a ground terminal and / or a common terminal; a discharge resistor and a discharge switch connected in parallel are provided between the ground terminal and the static contact; the control module is also configured to: obtain a voltage sampling value of the output channel, and control the discharge switch to close when the voltage sampling value is within a preset safety range.

[0013] Optionally, any one of the power distribution network insulation resistance testing devices provided in the embodiments of the present invention may also include: a channel status indication module, connected to the control module, for indicating the connection mode of each output channel; the connection mode includes any one of the following: connecting to the high-voltage output positive terminal, connecting to the high-voltage output negative terminal, or connecting to the discharge terminal.

[0014] Optionally, the control module used in any one of the distribution network insulation resistance testing devices provided in the embodiments of the present invention can be configured to: obtain the reference time required for the moving contact to move between two adjacent static contacts, and calculate the working time of the driving mechanism in the corresponding output channel based on the reference time and the initial position and target position in different output channels, and when the driving time of the driving mechanism reaches the working time, configure the target position to the position corresponding to the discharge end.

[0015] In the second aspect, an embodiment of the present invention further provides a distribution network insulation resistance testing method, which can be applied to any distribution network insulation resistance testing device provided by the embodiment of the present invention. The distribution network insulation resistance testing device includes multiple output channels and test terminals, the output channels are connected to moving contacts, and the test terminals are connected to static contacts. The method includes: obtaining the initial position of the moving contacts corresponding to different output channels; determining the target position of the moving contacts in the corresponding output channel according to the test requirements; controlling the movement of the corresponding moving contact according to the initial position and the target position, so that the moving contact is electrically connected to the static contact corresponding to the target position.

[0016] The power distribution network insulation resistance test device and test method provided by the embodiment of the present invention are provided with multiple output channels, test terminals, channel switching modules and control modules. The connection relationship between the multiple output channels and the power distribution network to be tested is adjusted by the channel switching module, and the test, discharge and reset processes are completed in sequence, thereby optimizing the cumbersome successive measurement, discharge and circuit switching processes in the existing insulation test work, realizing the automatic test of multiple groups of insulation resistance, improving the test efficiency, reducing the error rate of manual operation, and reducing the safety hazards in the insulation test process. By automatically discharging the tested circuit after the test is completed, while protecting the test equipment and the tested circuit, the operation process is further simplified, thereby significantly improving the safety and reliability of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of a power distribution network insulation resistance test device provided by an embodiment of the present invention;

[0018] Figure 2 A schematic diagram of the structure of a channel switching module provided by an embodiment of the present invention;

[0019] Figure 3 A circuit schematic diagram of a push rod control circuit provided by an embodiment of the present invention;

[0020] Figure 4 A flow chart of a method for testing insulation resistance of a power distribution network provided by an embodiment of the present invention;

[0021] Figure 5A flow chart of another method for testing insulation resistance of a power distribution network provided by an embodiment of the present invention;

[0022] Figure 6 A flow chart of another method for testing insulation resistance of a power distribution network provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0024] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. It should be noted that the "upper", "lower", "left" and "right" directional words described in the embodiments of the present invention are described at the angles shown in the accompanying drawings and should not be understood as limitations on the embodiments of the present invention. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is formed "on" or "under" another element, it can not only be directly formed "on" or "under" another element, but also indirectly formed "on" or "under" another element through an intermediate element. The terms "first" and "second" are used for descriptive purposes only and do not indicate any order, quantity or importance, but are only used to distinguish different components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention are understood in specific circumstances.

[0025] The term “including” and its variations used in the present invention are open inclusions, that is, “including but not limited to.” The term “based on” means “based at least in part on.” The term “one embodiment” means “at least one embodiment.”

[0026] It should be noted that the concepts of “first” and “second” mentioned in the present invention are only used to distinguish the corresponding contents, and are not used to limit the order or interdependence.

[0027] It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0028] Figure 1 A schematic diagram of the structure of a power distribution network insulation resistance test device provided by an embodiment of the present invention. Figure 1A distribution network insulation resistance test device 100 provided by an embodiment of the present invention comprises: a plurality of output channels 11, the output channels 11 being used to connect to a distribution network to be tested; a test terminal 20, at least comprising: a high-voltage output positive terminal 21, a high-voltage output negative terminal 22 and a discharge terminal 23; a channel switching module 30, arranged in one-to-one correspondence with the output channels 11, the channel switching module 30 comprising a static contact 32, a moving contact 31 and a driving mechanism 33, the static contact 32 being connected in one-to-one correspondence with the test terminal 20, the moving contact 31 being connected to the output channel 11, and the driving mechanism 33 being used to drive the moving contact 31 to move in a straight line direction; a control module 40, connected to a control end of the driving mechanism 33, being used to obtain an initial position of the moving contact 31 corresponding to different output channels 11, determining a target position of the moving contact 31 in the corresponding output channel 11 according to a test requirement, and controlling the corresponding driving mechanism 33 to extend or retract in a straight line direction according to the initial position and the target position, so that the moving contact 31 is electrically connected to the static contact 32 corresponding to the target position.

[0029] The power distribution network to be tested can be understood as a part of the power distribution network or components in the power system that needs to be tested for insulation resistance. Exemplarily, the power distribution network to be tested includes but is not limited to: single-phase cables, multi-phase (for example, two-phase or three-phase) cables, transformers, and switching elements; the output channel 11 can be understood as an interface in the power distribution network insulation resistance test device 100 for connecting the power distribution network to be tested; the test terminal 20 can be understood as a wiring terminal in the power distribution network insulation resistance test device 100 for providing a test voltage or a discharge circuit for the power distribution network to be tested. The test terminal 20 includes at least a high-voltage output positive terminal 21, a high-voltage output negative terminal 22, and a discharge terminal 23; wherein the high-voltage output positive terminal 21 is used to provide a forward test voltage to the power distribution network to be tested; the high-voltage output negative terminal 22 is used to provide a reverse test voltage to the power distribution network to be tested; the discharge terminal 23 can be understood as a special test terminal in the power distribution network insulation resistance test device 100, which is used to provide a discharge circuit for the power distribution network to be tested after the test is completed to release the residual charge in the power distribution network to be tested. The channel switching module 30 can be understood as a module for automatically switching between the connection relationship between the driving output channel 11 and different test terminals so as to test different distribution networks to be tested in turn; the static contact 32 can be understood as a fixed wiring terminal fixed on the test device and connected to the test terminal 20 in a one-to-one correspondence. The moving contact 31 can be understood as a wiring terminal that moves between the static contacts 32 through the movement of the driving mechanism 33 so as to be electrically connected to different static contacts 32. In this embodiment, the test terminal 20 outputs a test signal through the static contact 32. After the moving contact 31 is electrically connected to the static contact 32, the test signal is transmitted to the output channel 11 connected to the moving contact 31 through the moving contact 31.

[0030] In this embodiment, the connection relationship between the moving contact 31 and the stationary contact 32 is established based on the test requirements, wherein the test requirements include but are not limited to any of the following: phase-to-phase insulation resistance test requirements, phase-to-ground insulation resistance test requirements, transformer winding insulation resistance test requirements, transformer winding-to-ground insulation resistance test requirements, and post-test discharge requirements.

[0031] Specifically, in the present invention, the power distribution network insulation resistance test device 100 has a plurality of output channels 11, so that a plurality of power distribution networks to be tested can be connected simultaneously or sequentially for testing. The above-mentioned output channels 11 are arranged one by one with the channel switching modules 30 to ensure that each power distribution network to be tested can be tested through the corresponding output channel 11. The driving mechanism 33 is used to control the moving contact 31 to move in a straight line direction. Among them, the straight line direction is the arrangement direction of the static contact 32. The control module 40 is used to obtain the initial position of the moving contact 31 corresponding to different output channels 11, and determine the target position according to the test requirements. Then, the control module 40 generates a driving task according to the initial position and the target position, and controls the driving mechanism 33 corresponding to the output channel 11 to extend or retract in a straight line direction according to the driving task, so that the moving contact 31 on the driving mechanism 33 moves to the target position and is electrically connected to the static contact 32 corresponding to the target position. For example, if the initial position of the moving contact 31 is: the moving contact 31 is connected to the static contact 32 corresponding to the discharge end 23, and the target position corresponding to the test requirement is: the moving contact 31 is connected to the static contact 32 corresponding to the high-voltage output positive terminal 21, then the control module 40 determines the moving direction and target distance of the moving contact 31 according to the interval between the static contact 32 corresponding to the discharge end 23 and the static contact 32 corresponding to the high-voltage output positive terminal 21, and controls the drive mechanism 33 to extend or retract the target distance in a straight line direction based on the moving direction and moving distance. In addition, the control module 40 may also have other functions, such as automatic discharge after the test. After the test is completed, the target position corresponding to the test requirement is determined as: the moving contact 31 is connected to the static contact 32 corresponding to the discharge end 23, based on which, the drive mechanism 33 is controlled to extend or retract in a straight line direction, driving the moving contact 31 to return to the position where it is connected to the static contact 32 corresponding to the discharge end 23.

[0032] The power distribution network insulation resistance test device 100 provided in the embodiment of the present invention constructs an insulation resistance test device framework that can handle multiple test requirements simultaneously or in a logical order by designing multiple output channels 11. On this basis, the introduced channel switching module 30 and drive mechanism 33 realize the dynamic switching between the output channel and the test terminal. Finally, the control module 40 and the drive mechanism 33 cooperate to control the electrical connection between the moving contact 31 and the static contact 32 at the target position, thereby completing a set of insulation resistance test tasks. The insulation resistance test device framework provided in the embodiment of the present invention realizes the automated testing of the insulation resistance of the power distribution network, improves the test efficiency, and also reduces the error rate of manual operation.

[0033] Optionally, Figure 2 A schematic diagram of the structure of a channel switching module provided by an embodiment of the present invention. Figure 2 The static contact 32 of the present application includes a first conductive part 321 and a first insulating sheath 322 sleeved on the outer periphery of the first conductive part 321; the moving contact 31 includes a second conductive part 311 and a second insulating sheath 312 sleeved on the outer periphery of the second conductive part 311; when the moving contact 31 is connected to the static contact 32, the first conductive part 321 is in elastic interference contact with the second conductive part 311; when the moving contact 31 is not connected to the static contact 32, the minimum spacing distance between the first conductive part 321 and the second conductive part 311 is greater than a preset air insulation spacing; wherein the preset air insulation spacing is calculated based on the insulation resistance of the power distribution network to be tested.

[0034] Among them, the first conductive part 321 can be understood as a component used for the static contact 32 to conduct electricity; the first insulating sheath 322 can be understood as a protective layer sleeved on the outer periphery of the first conductive part 321, which is used to ensure the normal operation of the circuit (avoid abnormal conditions such as current leakage or short circuit) and ensure the safety of the operator. Similarly, the second conductive part 311 can be understood as a conductive component corresponding to the first conductive part 321 in the moving contact 31; the second insulating sheath 312 can be understood as a protective layer sleeved on the outer periphery of the second conductive part 311, which has a similar function to the first insulating sheath and is used to ensure the normal operation of the circuit. The preset air insulation interval can be understood as the minimum spacing distance set to ensure electrical insulation when the moving contact 31 is not connected to the static contact 32.

[0035] It should be noted that the preset air insulation interval is calculated based on the insulation resistance of the power distribution network to be tested to ensure that in the disconnected state, the contacts will not be damaged or cause safety accidents due to electrical discharge.

[0036] Specifically, the stationary contact 32 includes a first conductive part 321 and a first insulating sleeve sleeved around the outer periphery of the first conductive part 321. The moving contact 31 includes a second conductive part 321 and a second insulating sleeve sleeved around the outer periphery of the second conductive part 311. When the moving contact 31 is connected to the stationary contact 32, the first conductive part 321 and the second conductive part 311 are well electrically connected through elastic interference contact. When the moving contact 31 is not connected to the stationary contact 32, the minimum spacing distance between the first conductive part 321 and the second conductive part 311 is greater than the preset air insulation spacing to ensure that the first conductive part 321 and the second conductive part 311 are in a disconnected state.

[0037] Optionally, the first insulating sheath and the second insulating sheath are formed by using insulating material; the thickness of the insulating material is calculated based on the insulation resistance of the power distribution network to be tested.

[0038] The insulating material may be understood as an electrical material that has high resistance to electric current and can prevent or greatly limit the passage of electric current. For example, the insulating material may be an epoxy resin material.

[0039] It should be noted that the thickness of the insulating material is calculated based on the insulation resistance of the power distribution network to be tested to ensure sufficient insulation performance.

[0040] For example, the air insulation distance and the thickness of the epoxy resin material are designed based on the requirement that the insulation resistance of the 10KV voltage level is 100GΩ. According to Ohm's law: R = ρ*d / A (where ρ is the volume resistivity, d is the thickness of the material, and A is the cross-sectional area of ​​the material); the electric field formula: E = V / d (where V is the applied voltage and d is the thickness of the material), combining the above two formulas, it can be concluded that d = R*A / ρ. The resistivity of epoxy resin materials is usually around 10 12 -10 16 Ω·m. Assuming that the volume resistivity of a certain epoxy resin material is 10 14 Ω·m, the required epoxy resin thickness is 1 mm. In order to ensure the reliability of the design, the epoxy resin thickness of this solution is designed to be 2 mm.

[0041] For the calculation of air insulation gap, it is necessary to consider the breakdown voltage of air on the basis of the above content. The breakdown voltage of air at standard atmospheric pressure is about 30kV / cm (3000V / mm). This means that if the air insulation gap is too small, the air may undergo electrical breakdown and can no longer serve as an effective insulating medium. The volume resistivity of air is about 10 13 Ω·m, substituting into the formula d=R*A / ρ, it can be known that to achieve an insulation effect greater than 100GΩ at a voltage of 10kV, the required air insulation interval is 10mm. In order to ensure the reliability of the design, the air insulation interval of this solution is set to 20mm.

[0042] Specifically, the first insulating sheath and the second insulating sheath are respectively arranged on the static contact 32 and the moving contact 31, and their function is to effectively prevent safety problems caused by electric sparks that may be generated between the static contact 32 and the moving contact 31 when the static contact 32 and the moving contact 31 are in contact or disconnected operation. At the same time, by controlling the insulation interval between the first conductive part 321 and the second conductive part 311 to be greater than the preset air insulation interval, it is ensured that the first conductive part 321 and the second conductive part 311 maintain a stable disconnected state when they are not in a connected state, thereby ensuring the safe and stable operation of the entire power distribution system and the good realization of electrical performance.

[0043] See also Figure 2 The first conductive portion 321 includes two connecting pieces with conical cross sections; the second conductive portion 311 includes two trapezoidal connecting pieces, and the trapezoidal upper and lower surfaces of the trapezoidal connecting pieces are arranged opposite to each other.

[0044] The connecting piece may be understood as a component made of a material with good electrical conductivity and used to realize the electrical connection between the moving contact and the stationary contact.

[0045] Specifically, the first conductive part 321 includes two connecting pieces with conical sections, and the second conductive part 311 includes two trapezoidal connecting pieces, and the trapezoidal upper and lower surfaces of the trapezoidal connecting pieces are arranged oppositely. When the moving contact 31 contacts the stationary contact 32, the connecting piece with the conical section can produce a certain elastic deformation, thereby achieving close contact with the stationary contact 31. When the moving contact 32 contacts the stationary contact 31, the trapezoidal connecting piece can well adapt to the moving track of the moving contact, and when the moving contact 32 is in a connected state with the stationary contact 31, the trapezoidal upper and lower surfaces of the trapezoidal connecting piece are arranged oppositely to ensure that the connecting piece can provide a stable contact area.

[0046] Exemplarily, the main body of the driving mechanism 33 is made of a rod-shaped epoxy resin material, which has good insulation performance and mechanical strength, ensuring the stable operation of the driving mechanism in a complex electrical environment. A horizontal hole is provided at the end of the driving mechanism 33, and a copper column passes through the hole. The copper column serves as a conductive component, and a wiring screw is provided on one side for connecting the output channel 11, and a moving contact 31 is provided on the other side. The moving contact 31 is composed of two sliding connection copper sheets with conical sections. Such a design enables the moving contact 31 to maintain good conductivity and mechanical stability when in contact with the static contact 32. Correspondingly, four static contacts 32 are arranged on the moving path of the moving contact 31, and each static contact 32 is composed of two trapezoidal copper sheets, and the upper and lower parts are assembled inwardly to form an elastic contact interface. The static contact 32 is fixed through the epoxy resin tube to ensure its stability and reliability during the test process. When the moving contact 31 moves in a straight line under the drive of the driving mechanism 33 , the sliding copper sheet of its conical section will be elastically slidably connected with the trapezoidal copper sheet of the stationary contact 32 , thereby realizing the switching between different test terminals 20 .

[0047] Continue to see Figure 2 The driving mechanism 33 is used to fix the moving contact 31; the push rod control circuit 34 is used to control the extension movement of the electric telescopic rod when receiving the first control signal output by the control module 40; and to control the retraction movement of the electric telescopic rod when receiving the second control signal output by the control module 40.

[0048] Among them, the first control signal can be understood as an instruction signal output by the control module 40, which is used to instruct the push rod control circuit 34 to control the driving mechanism 33 to perform an extension movement; the second control signal can be understood as a signal used to instruct the push rod control circuit 34 to control the driving mechanism 33 to perform a retraction movement.

[0049] Specifically, in the power distribution network insulation resistance test device, in order to realize automatic switching of the test terminal 20, when the push rod control circuit 34 in the drive mechanism 33 receives a first control signal, it controls the drive mechanism 33 to extend; when receiving the second control signal output by the control module 40, it controls the drive mechanism 33 to retract.

[0050] Figure 3 A circuit schematic diagram of a push rod control circuit provided by an embodiment of the present invention, such as Figure 3 As shown, optionally, the push rod control circuit 34 includes: a drive motor 351, a forward drive branch 352 (see Figure 3 The green line in the middle) and the reverse drive branch 353 (see Figure 3The driving motor 351 is connected to the driving mechanism 33; the forward driving branch 352 is used to apply a forward voltage to the driving motor 351 when receiving a first control signal, so that the driving motor 351 rotates forward and drives the driving mechanism 33 to extend; the reverse driving branch 353 is used to apply a reverse voltage to the driving motor 351 when receiving a second control signal, so that the driving motor 351 reverses and drives the driving mechanism 33 to retract.

[0051] Specifically, when the control module 40 sends a first control signal or a second control signal to the push rod control circuit 34 according to the test requirements and in combination with the moving direction and target interval of the moving contact 31 between the initial position and the target position. When the target position is in the extension direction of the drive mechanism 33, the control module 40 sends a first control signal to the push rod control circuit 34, the forward drive branch 352 is turned on, and a forward voltage is applied to the drive motor 351. At this time, the motor rotates forward, and the drive mechanism 33 performs an extension movement until the moving contact 31 is electrically connected to the test terminal 20 at the target position; similarly, when the target position is in the retraction direction of the drive mechanism 33, the control module 40 sends a second control signal to the push rod control circuit 34, the reverse drive branch 353 is turned on, and a reverse voltage is applied to the drive motor 351. At this time, the drive motor 351 reverses, and the drive mechanism 33 performs a retraction movement until the moving contact 31 is electrically connected to the test terminal 20 at the target position.

[0052] For example, the push rod control circuit 34 is connected by the normally open and normally closed points of two relays in a staggered manner. When the forward relay coil is energized and the reverse relay is not energized, the relay contact is switched from the normally closed contact to the normally open contact, so that the negative pole of the motor is grounded and the positive pole is connected to the positive power source. The motor of the electric push rod is powered by the positive power and extends outward to make a linear motion. Similarly, when the forward relay is not powered and the reverse relay is powered, the motor of the electric push rod is powered by the reverse power and retracts in a linear motion. The two relays are driven and controlled by two three-stage tubes controlled by a single-chip microcomputer.

[0053] Alternatively, see Figure 1 As shown, the discharge terminal 23 includes a ground terminal and / or a common terminal; a discharge resistor R and a discharge switch K connected in parallel are provided between the ground terminal and the static contact 32; the control module 40 is also configured to: obtain the voltage sampling value of the output channel, and control the discharge switch K to close when the voltage sampling value is within a preset safety range.

[0054] The discharge terminal 23 may include a ground terminal and / or a common terminal, and both the ground terminal and the common terminal are grounded. The ground terminal is specifically used to perform a discharge operation to ensure that the residual charge can be effectively released after the test is completed. The common terminal is used to place the moving contact 31 in a non-test state. The moving contacts 31 of all output channels are connected to the common terminal (usually also grounded) by default in a non-test state to prevent unexpected situations and ensure the safety and stability of the overall equipment.

[0055] Specifically, when the voltage sampling value of the output channel obtained by the control module 40 is not within the preset safety range, the circuit limits the size of the discharge current through the discharge resistor R (such as a cement resistor), thereby protecting the circuit and the device from the impact of instantaneous large current. After a period of band-resistance discharge, when the voltage sampling value is reduced to the preset safety range or the voltage sampling value itself is within the preset safety range, the discharge switch K is closed, and the circuit is in a short-circuit discharge state. Short-circuit discharge can quickly release the charge, reduce the discharge time, and improve the test efficiency.

[0056] Optionally, any one of the power distribution network insulation resistance testing devices 100 provided in the embodiments of the present invention may also include: a channel status indication module, connected to the control module 40, for indicating the connection mode of each output channel 11; the connection mode includes any one of the following: connecting to the high-voltage output positive terminal 21, connecting to the high-voltage output negative terminal 22, or connecting to the discharge terminal 23.

[0057] Specifically, the channel status indication module can be composed of a group of indicator lights (such as LED lights) or digital display screens and other components. Each output channel corresponds to a group of indicator lights or a display screen for real-time display of the connection status of the channel. Exemplarily, the channel status indication module is a group of indicator lights. When the light is off, it means that it is connected to the common terminal (ground); when the indicator light is green, it means that it is connected to the ground terminal (discharge); when the indicator light is yellow, it means that it is connected to the negative pole of the high-voltage output; when the indicator light is red, it means that it is connected to the positive pole of the high-voltage output.

[0058] Optionally, the control module 40 used in any one of the distribution network insulation resistance testing devices 100 provided in the embodiments of the present invention can be configured to: obtain the reference time required for the moving contact 31 to move between two adjacent static contacts 32, and calculate the working time of the driving mechanism 33 in the corresponding output channel 11 based on the reference time and the initial position and target position in different channels, and when the driving time of the driving mechanism reaches the working time, configure the target position to the position corresponding to the discharge end 23.

[0059] The reference time may be understood as the time required for the moving contact 31 to move between two adjacent stationary contacts 32 . The reference time may be obtained through experimental measurement or theoretical calculation and stored in the control module 40 .

[0060] Specifically, based on the acquired reference time, combined with the initial position and target position of the moving contact 31 in different channels, the control module 40 calculates the working time of the driving mechanism 33 in the corresponding output channel 11. When the test task is completed, when the driving time of the driving mechanism reaches the working time, the target position is configured as the position corresponding to the discharge end 23, and the moving contact 31 is controlled to move to the discharge end to automatically complete the discharge process.

[0061] Exemplarily, the reference time is obtained in the following manner: the time required for the moving contact 31 to move between adjacent stationary contacts 32 is obtained by a timer as the reference time.

[0062] Based on the power distribution network insulation resistance testing device 100 of the above embodiment, the embodiment of the present invention further provides a testing method of the power distribution network insulation resistance testing device 100. Figure 4 A flow chart of a method for testing the insulation resistance of a power distribution network provided by an embodiment of the present invention, referring to Figure 4 The power distribution network insulation resistance test method can be applied to any power distribution network insulation resistance test device 100 provided in the embodiment of the present invention. The power distribution network insulation resistance test device 100 includes a plurality of output channels 11 and a test terminal 20. The output channel 11 is connected to a moving contact 31, and the test terminal 20 is connected to a static contact 32. The specific steps of the method are as follows:

[0063] S110, obtaining initial positions of moving contacts corresponding to different output channels.

[0064] Among them, the initial position of the moving contact is set at the discharge end by default when there is no test task, so as to ensure that all moving contacts are in a safe and known position before the test, which is convenient for subsequent test operations.

[0065] Specifically, before the test is performed, in order to ensure that the moving contact can accurately move from the current position to the target position, the control module will issue a detection instruction to obtain the current position information of each moving contact, that is, the initial position, through a sensor or a position detection device.

[0066] S120. Determine a target position of a moving contact in a corresponding output channel according to a test requirement.

[0067] Among them, the test requirements can be understood as the requirements put forward according to specific test items and standards during the insulation performance detection or maintenance of power equipment. Exemplary requirements include but are not limited to any of the following: phase-to-phase insulation resistance test requirements, phase-to-ground insulation resistance test requirements, transformer winding insulation resistance test requirements, transformer winding-to-ground insulation resistance test requirements and post-test discharge requirements.

[0068] Specifically, according to the test requirements, the control module determines the target positions to which the moving contacts in each output channel need to move, and these target positions usually correspond to various test points of the power distribution network to be tested.

[0069] S130, controlling the corresponding moving contact to move according to the initial position and the target position, so that the moving contact is electrically connected to the static contact corresponding to the target position.

[0070] Specifically, the control module will calculate the distance and direction that the moving contact needs to move based on the relevant information of the initial position and the target position. On this basis, the moving path and moving time of the moving contact corresponding to each output channel that needs to be tested are further calculated. Subsequently, the forward or reverse time of the drive motor is calculated based on the moving path and moving time. Finally, the control module will issue corresponding control instructions to the drive mechanism. After receiving the instruction, the drive mechanism will drive the moving contact to move in a straight line until the moving contact is successfully electrically connected to the static contact corresponding to the target position.

[0071] The technical solution of the embodiment of the present invention obtains the initial position of the moving contact corresponding to different output channels, and then determines the current state of each output channel. Subsequently, the target position of the moving contact in the corresponding output channel is determined according to the test requirements, providing a clear target for subsequent test operations. On this basis, the control module will control the movement of the moving contact according to the information of the initial position and the target position, so that the moving contact is electrically connected to the static contact corresponding to the target position, thereby performing an insulation resistance test. Finally, after the test is completed, the moving contact will be moved to the discharge end again and perform a discharge operation to ensure the safe reset of the test device and the reliability and safety of the entire test process. The technical solution of the embodiment of the present invention realizes the insulation resistance test with automatic switching of multiple channels, improves the test efficiency, and also reduces the complexity and error rate of manual operation, and increases the safety of the insulation resistance test.

[0072] Figure 5 A flow chart of another distribution network insulation resistance testing method provided for an embodiment of the present invention. The embodiment of the present invention is a refinement or optimization of the above-mentioned embodiment. Specifically, the discharge terminal includes a ground terminal and / or a common terminal; a discharge resistor and a discharge switch connected in parallel are provided between the ground terminal and the static contact; the control module is also configured to: obtain a voltage sampling value of an output channel, and control the discharge switch to close when the voltage sampling value is within a preset safety range.

[0073] like Figure 5 As shown, the method includes:

[0074] S210: Acquire initial positions of moving contacts corresponding to different output channels.

[0075] S220. Determine a target position of a moving contact in a corresponding output channel according to a test requirement.

[0076] S230, controlling the corresponding moving contact to move according to the initial position and the target position, so that the moving contact is electrically connected to the static contact corresponding to the target position.

[0077] S231. Move the moving contact to the discharge end.

[0078] Specifically, after a set of insulation voltage tests are completed, a discharge operation needs to be performed on the test circuit. At this time, the push rod control circuit drives the moving contact on the electric telescopic rod to move to the static contact corresponding to the discharge point end.

[0079] S232. Obtain the voltage sampling value of the output channel.

[0080] Specifically, the control module obtains the voltage sampling value of the output channel, and the obtained voltage sampling value of the output channel is used to determine whether it is necessary to connect a discharge resistor for protective discharge.

[0081] S233: When the voltage sampling value is within a preset safety range, control the discharge switch to close.

[0082] Specifically, when the voltage sampling value of the output channel is higher than the safety range, the discharge end is discharged in series with a discharge resistor (such as a cement resistor), and the charge is discharged after passing through the cement resistor to avoid excessive current causing instantaneous large current impact on the circuit and equipment; when the voltage sampling value of the output channel is within the safety range, the discharge switch connected in parallel with the discharge resistor is closed, and the charge will be connected to the ground through the wire to achieve the purpose of rapid discharge.

[0083] The technical solution of the embodiment of the present invention divides the discharge process into two modes: band-resistance discharge and direct discharge by detecting the voltage sampling value of the output channel. The energy release in the band-resistance discharge mode is relatively smooth to avoid excessive current from causing instantaneous large current impact on circuits and equipment. When the voltage sampling value drops to a safe range, or the voltage sampling value itself is within the safe range, the control module controls the discharge switch to close and quickly completes the discharge process.

[0084] Figure 6 A flow chart of another distribution network insulation resistance testing method provided for an embodiment of the present invention. The embodiment of the present invention is a refinement or optimization of the above embodiment. Specifically, the control module is configured to: obtain a reference time required for a moving contact to move between two adjacent static contacts, and calculate the working time of a driving mechanism in a corresponding output channel according to the reference time and the initial position and target position in different output channels, and when the driving time of the driving mechanism reaches the working time, configure the target position to the position corresponding to the discharge end.

[0085] like Figure 6As shown, the method includes:

[0086] S310: Obtain initial positions of moving contacts corresponding to different output channels.

[0087] S320. Determine a target position of a moving contact in a corresponding output channel according to a test requirement.

[0088] S321. Obtain a reference time required for a moving contact to move between two adjacent stationary contacts.

[0089] Specifically, the reference time may be understood as the time required for the moving contact to move between two adjacent stationary contacts. The reference time may be obtained through experimental measurement or theoretical calculation.

[0090] S322, calculating the working time of the driving mechanism in the corresponding output channel according to the reference time and the initial position and target position in different output channels.

[0091] Specifically, based on the acquired reference time, combined with the initial position and target position of the moving contact in different output channels, the control module calculates the working time of the driving mechanism in the corresponding output channel. Distance control is converted into time control, which simplifies the control logic and ensures that the moving contact can move to the target position in a timely and accurate manner.

[0092] S323: When the driving time of the driving mechanism reaches the working time, the target position is configured as a position corresponding to the discharge end.

[0093] Specifically, when the driving time of the driving mechanism reaches the working time, the current test task is deemed to be completed, and the target position is configured as the position corresponding to the discharge end. At this time, according to the target position, the driving mechanism controls the moving contact to be connected to the discharge end.

[0094] S330, controlling the corresponding moving contact to move according to the initial position and the target position, so that the moving contact is electrically connected to the static contact corresponding to the target position.

[0095] The embodiment of the present invention introduces the concept of reference time, transforms complex distance control into intuitive time control, simplifies the control logic, and enables the moving contact to move to the target position quickly and accurately, thereby fully ensuring the accuracy of the test. After the preset working time ends, the present invention automatically sets the target position to the position corresponding to the discharge end, thereby realizing the function of automatic discharge and improving the safety and convenience of operation.

[0096] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, but also includes more effective embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A power distribution network insulation resistance test device, characterized in that: include: A plurality of output channels, wherein the output channels are used to connect to a power distribution network to be tested; The test terminal includes at least: a high voltage output positive terminal, a high voltage output negative terminal and a discharge terminal; A channel switching module is arranged in a one-to-one correspondence with the output channels, the channel switching module comprises a static contact, a moving contact and a driving mechanism, the static contact is connected to the test terminals in a one-to-one correspondence, the moving contact is connected to the output channels, and the driving mechanism is used to drive the moving contact to move in a straight line direction; A control module is connected to the control end of the driving mechanism, and is used to obtain the initial position of the moving contact corresponding to different output channels, determine the target position of the moving contact in the corresponding output channel according to the test requirements, and control the corresponding driving mechanism to extend or retract in a straight line direction according to the initial position and the target position, so that the moving contact is electrically connected to the static contact corresponding to the target position.

2. The power distribution network insulation resistance test device according to claim 1, characterized in that: The stationary contact comprises a first conductive portion and a first insulating sheath sleeved around the outer periphery of the first conductive portion; The moving contact comprises a second conductive portion and a second insulating sheath sleeved around the outer periphery of the second conductive portion; When the moving contact is connected to the stationary contact, the first conductive part is in elastic interference contact with the second conductive part; When the moving contact is not connected to the stationary contact, the minimum spacing distance between the first conductive part and the second conductive part is greater than a preset air insulation interval; wherein the preset air insulation interval is calculated based on the insulation resistance of the power distribution network to be tested.

3. The power distribution network insulation resistance test device according to claim 2, characterized in that: The first insulating sheath and the second insulating sheath are made of insulating material; The thickness of the insulating material is calculated based on the insulation resistance of the power distribution network to be tested.

4. The power distribution network insulation resistance test device according to claim 2, characterized in that: The first conductive portion includes two connecting pieces with conical sections; The second conductive portion includes two trapezoidal connecting pieces, and the trapezoidal upper and lower surfaces of the trapezoidal connecting pieces are arranged opposite to each other.

5. The power distribution network insulation resistance test device according to claim 1, characterized in that: The driving mechanism comprises: An electric telescopic rod, used for fixing the moving contact; The push rod control circuit is used to control the extension movement of the electric telescopic rod when receiving the first control signal output by the control module; and to control the retraction movement of the electric telescopic rod when receiving the second control signal output by the control module.

6. The power distribution network insulation resistance test device according to claim 5, characterized in that: The push rod control circuit includes: a drive motor, a forward drive branch and a reverse drive branch; The driving motor is meshingly connected with the electric telescopic rod; The forward drive branch is used to apply a forward voltage to the drive motor upon receiving the first control signal, so that the drive motor rotates forward and drives the electric telescopic rod to extend; The reverse driving branch is used to apply a reverse voltage to the driving motor when receiving the second control signal, so as to reverse the driving motor and drive the electric telescopic rod to retract.

7. The power distribution network insulation resistance test device according to claim 1, characterized in that: The discharge terminal includes a ground terminal and / or a common terminal; A discharge resistor and a discharge switch connected in parallel are provided between the ground terminal and the static contact; The control module is further configured to: obtain a voltage sampling value of the output channel, and control the discharge switch to close when the voltage sampling value is within a preset safety range.

8. The power distribution network insulation resistance test device according to any one of claims 1 to 7, characterized in that: Also includes: A channel status indication module, connected to the control module, for indicating the connection mode of each output channel; The connection method includes any one of the following: connecting to the high-voltage output positive terminal, connecting to the high-voltage output negative terminal, or connecting to the discharge terminal.

9. The power distribution network insulation resistance test device according to any one of claims 1 to 7, characterized in that: The control module is configured to: obtain a reference time required for the moving contact to move between two adjacent static contacts, and calculate the working time of the driving mechanism in the corresponding output channel according to the reference time and the initial position and the target position in different output channels, and when the driving time of the driving mechanism reaches the working time, configure the target position to the position corresponding to the discharge end.

10. A method for testing the insulation resistance of a power distribution network, characterized in that: The method is implemented based on a power distribution network insulation resistance test device according to any one of claims 1 to 9, wherein the power distribution network insulation resistance test device comprises a plurality of output channels and test terminals, wherein the output channels are connected to moving contacts, and the test terminals are connected to stationary contacts. Obtaining the initial positions of the moving contacts corresponding to different output channels; Determine the target position of the moving contact in the corresponding output channel according to the test requirements; The corresponding moving contact is controlled to move according to the initial position and the target position, so that the moving contact is electrically connected to the static contact corresponding to the target position.

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