Power distribution network secondary terminal test circuit and equipment

Abstract

The invention discloses a test circuit and equipment for a secondary terminal of a power distribution network. The circuit comprises a line power supply generation module, a line working environment simulation module, a switch body module and a port module, the line power generation module is used for providing a three-phase power supply; the line working environment simulation module is used for simulating input scenes of a plurality of three-phase power supplies, and is also used for realizing zero-sequence voltage input or quit and zero-sequence current input or quit functions; the switch body module is used for simulating the working state and the fault condition of the circuit breaker; the port module is used for being electrically connected with a secondary terminal of the power distribution network. The system has the advantages of being good in portability, high in integration level, high in reproduction degree and low in cost, and can comprehensively and accurately test the functions and characteristics of the power distribution terminal.

Description

Technical Field

[0001] The present invention relates to the technical field of distribution terminal testing, and particularly to a secondary terminal testing circuit and device for a distribution network. Background Art

[0002] During the research and development, testing, production, and joint debugging processes of secondary terminal equipment for a distribution network, it is necessary to test functions such as logic, protection, and measurement of intelligent distribution terminals. In this process, common testing equipment solutions include a relay protection tester (hereinafter referred to as a relay protection instrument) combined with a real circuit breaker, an automated testing platform, a relay protection instrument combined with a simulated circuit breaker, etc. Among them, the solution of a relay protection instrument combined with a real circuit breaker is the testing solution closest to the actual usage environment, so it is usually used as the testing solution during the factory inspection and joint debugging of distribution terminals. However, the relay protection instrument is costly, the primary switch is large in volume and heavy in weight, resulting in it being not easy to move, and there are certain inconveniences in the research and development and testing links. Moreover, increasing the primary switch usually requires cooperation with a step-up transformer, a current booster, etc., and special attention needs to be paid to the personal safety of operators.

[0003] The automated testing platform is highly automated and intelligent, and can basically handle all logic and function tests. However, its cost is higher and its popularity is very low, so it is usually used in the research and development testing link and is not suitable for simple tests during unit testing and software development.

[0004] The solution of a relay protection instrument combined with a simulated circuit breaker is the most flexible solution, which uses a simulated circuit breaker to replace the real circuit breaker. It occupies a small area and is light in weight, and can build a test environment anytime and anywhere, and can meet most requirements of manufacturers of secondary terminal equipment for a distribution network. However, the simulated circuit breaker can only simulate some working conditions, and cannot simulate such as circuit breaker failures and line failures in actual applications. Coupled with the high cost of the relay protection instrument, it also has certain limitations.

[0005] In view of the above advantages and disadvantages of the applications, if there is a testing platform with low cost, portability, closer to the actual usage environment, greater expression of circuit breaker and line failures, and capable of outputting three-phase voltage and current, it will be an effective supplement to the testing equipment solution for secondary terminal equipment, can reduce the time for building a test environment, and is especially suitable for some relatively simple unit testing and function testing scenarios. Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides a secondary terminal testing circuit for a distribution network, which can simultaneously have the advantages of good portability, high integration, high reproducibility, and low cost, and accurately test the functions and characteristics of a distribution terminal.

[0007] The present invention also provides a distribution network secondary terminal testing device having the above-mentioned distribution network secondary terminal testing circuit.

[0008] The distribution network secondary terminal testing circuit according to the first aspect embodiment of the present invention includes: A line power generation module for providing three-phase power; A line working environment simulation module electrically connected to the line power generation module, for simulating several input scenarios of the three-phase power, and also for implementing the function of inputting or withdrawing zero-sequence voltage and inputting or withdrawing zero-sequence current; A switch body module electrically connected to the line working environment simulation module and also electrically connected to the line power generation module, for simulating the working state and fault conditions of the circuit breaker; A port module electrically connected to the switch body module and also for electrically connecting to the distribution network secondary terminal.

[0009] In some embodiments of the present invention, the line power generation module includes: A DC power supply for providing line power and control power; A single-chip microcomputer electrically connected to the DC power supply, for receiving and adjusting the line power; A voltage three-phase inverter, the input end of which is electrically connected to the single-chip microcomputer, and the output end of which is electrically connected to the line working environment simulation module, for converting the line power into three-phase AC voltage and outputting it to the line working environment simulation module; A current three-phase inverter, the input end of which is electrically connected to the single-chip microcomputer, and the output end of which is electrically connected to the switch body module, for converting the line power into three-phase AC current and outputting it to the switch body module; A voltage amplitude adjustment knob electrically connected to the single-chip microcomputer; A current amplitude adjustment knob electrically connected to the single-chip microcomputer; A frequency adjustment knob electrically connected to the single-chip microcomputer.

[0010] In some embodiments of the present invention, the line working environment simulation module includes: A first relay, the input end of which is electrically connected to the output end of the voltage three-phase inverter, and the output end of which is electrically connected to the input end of the switch body module, and the first relay is used for simulating the voltage input scenario on the incoming line side of the circuit breaker; A first self-locking button electrically connected to the control end of the first relay; A second relay, the input end of the second relay is electrically connected to the output end of the three-phase voltage inverter, the output end of the second relay is electrically connected to the output end of the switch body module, and the second relay is used to simulate the voltage input scenario on the outgoing side of the circuit breaker; A second self-locking button, the second self-locking button is electrically connected to the control end of the second relay.

[0011] In some embodiments of the present invention, the line working environment simulation module further includes: A zero-voltage input / output self-locking switch, one end of the zero-voltage input / output self-locking switch is electrically connected to one phase of the output end of the three-phase voltage inverter, and the other end of the zero-voltage input / output self-locking switch is electrically connected to the input end of the first relay and the input end of the second relay; A zero-current input / output self-locking switch, one end of the zero-current input / output self-locking switch is electrically connected to one phase of the output end of the three-phase current inverter, and the other end of the zero-current input / output self-locking switch is electrically connected to the input end of the third relay.

[0012] In some embodiments of the present invention, the switch body module includes: A third relay, used to simulate a three-phase current circuit breaker, the input end of the third relay is electrically connected to the three-phase current inverter, and the output end of the third relay is electrically connected to the port module; A fourth relay, used to simulate a three-phase voltage circuit breaker, the input end of the fourth relay is electrically connected to the output end of the first relay, the input end of the fourth relay is also electrically connected to the port module, the output end of the fourth relay is electrically connected to the output end of the second relay, and the output end of the fourth relay is also electrically connected to the port module; A fifth relay, the input end of the fifth relay is electrically connected to the control power supply, the output end of the fifth relay is electrically connected to the control end of the third relay and the control end of the fourth relay, and the fifth relay uses a double-coil magnetic latching relay.

[0013] In some embodiments of the present invention, the switch body module further includes: A local logic module, the output end of the local logic module is electrically connected to the control end of the fifth relay; A local switch closing button, one end is electrically connected to the control power supply, and the other end is electrically connected to the input end of the local logic module; A local switch tripping button, one end is electrically connected to the control power supply, and the other end is electrically connected to the input end of the local logic module; The remote / local switching button has one end electrically connected to the control power supply and the other end electrically connected to the input end of the local logic module; The trip position with current button has one end electrically connected to the control power supply and the other end electrically connected to the control end of the third relay; The switch refusal to operate normally closed button has one end electrically connected to the control power supply and the other end electrically connected to the input end of the local logic module; The switch unenergized time adjustment knob is electrically connected to the input end of the local logic module; The switch unenergized indicator light is electrically connected to the output end of the local logic module.

[0014] In some embodiments of the present invention, the port module includes: The incoming line voltage sampling socket is electrically connected to the input end of the fourth relay and is also used for electrically connecting to the secondary terminal of the distribution network; The outgoing line voltage sampling socket is electrically connected to the output end of the fourth relay and is also used for electrically connecting to the secondary terminal of the distribution network; The current sampling socket is electrically connected to the output end of the third relay and is also used for electrically connecting to the secondary terminal of the distribution network; The switch trip position remote signaling terminal is electrically connected to the output end of the local logic module and is also used for electrically connecting to the secondary terminal of the distribution network; The switch close position remote signaling terminal is electrically connected to the output end of the local logic module and is also used for electrically connecting to the secondary terminal of the distribution network; The switch remote closing terminal is electrically connected to the output end of the local logic module and is also used for electrically connecting to the secondary terminal of the distribution network; The switch remote tripping terminal is electrically connected to the output end of the local logic module and is also used for electrically connecting to the secondary terminal of the distribution network; The switch unenergized position terminal is electrically connected to the output end of the local logic module and is also used for electrically connecting to the secondary terminal of the distribution network.

[0015] In some embodiments of the present invention, a meter module is further provided, and the meter module includes: A three-phase AC voltmeter is arranged between the voltage three-phase inverter and the line working environment simulation module; A three-phase AC ammeter is arranged between the current three-phase inverter and the switch body module.

[0016] The secondary terminal test equipment of the distribution network according to the second aspect embodiment of the present invention includes: A housing; An operation panel, which is arranged on one side of the housing and is used for electrically connecting with the secondary terminal of the distribution network; A circuit board module, which is arranged inside the housing and is electrically connected with the operation panel. The circuit board module is provided with a test circuit for the secondary terminal of the distribution network as described in the embodiments of the above aspect. The operation panel is also used to adjust the working state of the circuit board module.

[0017] In some embodiments of the present invention, the circuit board module includes: An operation panel PCB, which is electrically connected with the operation panel. The operation panel PCB is provided with a port module; A DC power supply and an inverter control board, which is electrically connected with the operation panel PCB. The DC power supply and the inverter control board are used to form a line power generation module; A main control board, which is electrically connected with the power supply and the inverter control board and is also electrically connected with the operation panel PCB. The main control board is provided with a line working environment simulation module and a switch body module.

[0018] The secondary terminal circuit and equipment of the distribution network according to the embodiments of the present invention have at least the following beneficial effects: By setting up a line power generation module, low-voltage direct current can be converted into three-phase four-wire alternating current simulating the actual working conditions of the distribution network terminal, which can provide power for equipment such as the tested distribution terminal without the need for an additional power supply; By setting up a line working environment simulation module and a switch body module electrically connected thereto, the actual working conditions of the primary switch can be comprehensively simulated. It is equivalent to moving the on-site environment to the laboratory. The two inverter modules inside are simulated as the power output of the low-voltage side of the substation and can simulate the situation of power coming from both sides of the primary switch; By setting up a port module, the connection ports of the present invention with the distribution terminal cover all the functions of the real primary switch. For the distribution terminal, the present invention is a real circuit breaker. The interaction between the present invention and the operator not only includes the operation of the simulated circuit breaker but also the operation of the line working conditions; By integrating all the modules required for testing into a circuit board and placing them in the secondary terminal equipment of the distribution network, the portability of the present invention is improved and the cost is reduced.

[0019] The additional aspects and advantages of the present invention will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present invention. Description of the Drawings

[0020] The following further describes the present invention in conjunction with the drawings and embodiments, where: Figure 1 is a module connection diagram of the test circuit for the secondary terminal of the distribution network according to the embodiment of the present invention; Figure 2It is the electrical schematic diagram of the secondary terminal test circuit of the distribution network according to the embodiment of the present invention; Figure 3 It is the overall structural schematic diagram of the secondary terminal test equipment of the distribution network according to the embodiment of the present invention; Figure 4 It is the exploded view of the structure of the secondary terminal test equipment of the distribution network according to the embodiment of the present invention; Figure 5 It is the schematic diagram of the panel of the secondary terminal test equipment of the distribution network according to the embodiment of the present invention.

[0021] Reference numerals: line power generation module 100, DC power supply 110, single-chip microcomputer 120, three-phase voltage inverter 130, three-phase current inverter 140, voltage amplitude adjustment knob 150, current amplitude adjustment knob 160, frequency adjustment knob 170; meter module 200, three-phase AC voltmeter 210, three-phase AC ammeter 220; line working environment simulation module 300; switch body module 400; port module 500; operation panel 600, panel anti-collision bar 610, foot pad 620; housing 700, front panel 710, corner guard 711, side panel 720, rear panel 730, bottom panel 740; operation panel PCB 810, inverter control board 820, main control board 830, three-phase transformer 831. Detailed implementation manners

[0022] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0023] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as up, down, front, back, left, right, etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0024] In the description of the present invention, the meaning of several is more than one, the meaning of multiple is more than two, greater than, less than, exceeding, etc. are understood as not including the present number, and above, below, within, etc. are understood as including the present number. If there is a description of first and second, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0025] In the description of the present invention, unless otherwise clearly defined, terms such as "set", "installed", "connected", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0026] In the description of the present invention, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0027] The following combines the attached Figures 1 - 5 to describe in detail the distribution network secondary terminal test circuit and equipment of the embodiments of the present invention.

[0028] Refer to Figure 1 and Figure 2 The present invention provides a distribution network secondary terminal test circuit, including: A line power generation module 100 for providing three-phase power; A line working environment simulation module 300 electrically connected to the line power generation module 100, for simulating several input scenarios of three-phase power, and also for implementing the function of inputting or withdrawing zero-sequence voltage and inputting or withdrawing zero-sequence current; A switch body module 400 electrically connected to the line working environment simulation module 300 and also electrically connected to the line power generation module 100, for simulating the working state and fault conditions of the circuit breaker; A port module 500 electrically connected to the switch body module 400 and also for electrically connecting to the distribution network secondary terminal.

[0029] Specifically, in this embodiment, as Figure 1 shown, the distribution network secondary terminal equipment test circuit includes a line power generation module 100, a meter module 200, a line working environment simulation module 300, a switch body module 400, and a connection port module 500 between the switch body and the intelligent power distribution terminal.

[0030] The line power generation module 100 mainly includes: a DC power supply 110, two DC / AC modules (inverters) for generating three-phase AC power (including a voltage three-phase inverter 130 and a current three-phase inverter 140), and a voltage amplitude and frequency adjustment part (including a voltage amplitude adjustment knob 150, a current amplitude adjustment knob 160, and a frequency adjustment knob 170).

[0031] The meter module 200 includes a three-phase AC voltage meter 210 and a three-phase AC ammeter 220.

[0032] The line working environment simulation module 300 is mainly used to implement the following functions: realizing the scenarios where the power input end is the incoming line side or the outgoing line side or both sides are energized, and realizing zero-voltage switching and zero-current switching.

[0033] The switch body module 400 is mainly used to implement the following functions: point-moving type switch opening and closing control, remote / local switching, local opening and closing buttons, intuitive display of switch status and electrical signal indication, realization and setting of energy storage time, and fault simulation of the switch.

[0034] The approximate electrical connection relationships between the above-mentioned various modules or components are as Figure 2 shown.

[0035] More specifically, the DC power supply 110 is used to supply power to the entire test platform, such as the DC bus power supply of the inverter and the internal control signal power supply, and a buck-type DC / DC power supply chip is used to generate a 5V power supply and a 12V power supply respectively, which are used as the working power supplies for components such as the internal single-chip microcomputer, logic chip, and signal relay.

[0036] Two DC / AC modules (including a three-phase voltage inverter 130 and a three-phase current inverter 140) are respectively used to generate two groups of three-phase three-wire UVW signals with the same phase, which are respectively input into two independent SD-type transformers, and after △-Y transformation, three-phase four-wire AC voltages of ABCN are output. One path is a power supply boosted to a maximum effective value of AC120V, which is used to simulate the output of a voltage transformer in a real scenario; the other path is a power supply with a generated effective value of up to AC6V, and a small-value high-power resistor is respectively connected in series to form a current, which is used to simulate the output of a current transformer in a real scenario.

[0037] The voltage amplitude and frequency adjustment part (including a voltage amplitude adjustment knob 150, a current amplitude adjustment knob 160, and a frequency adjustment knob 170) belongs to the extended part of the two DC / AC modules, and the amplitude and frequency requirements can be input to the single-chip microcomputer by means of a mechanical knob or a liquid crystal plus operation panel, and the single-chip microcomputer 120 performs adjustment actions to change the output voltage amplitude.

[0038] The meter module 200 includes a three-phase AC voltage meter 210 and a three-phase AC ammeter 220, which are used to indicate the effective voltage value and effective current value of the analog voltage transformer and current transformer output by the three-phase voltage inverter 130 and the three-phase current inverter 140.

[0039] When the line working environment simulation module 300 implements the scenario where the power input end is the incoming line side or the outgoing line side or both sides are energized, as Figure 2 shown, the normally open contacts of the relays RLY3 and RLY4 representing the switch body are respectively connected to the power bus through the normally open contacts of the relays RLY1 and RLY2. Finally, the voltage sampling is output to the outside of the test platform through the banana socket and connected to the intelligent power distribution terminal. The self-locking buttons SB1 and SB2 respectively control the monostable relays RLY1 and RLY2. When the button SB1 is pressed, RLY1 is attracted, indicating that the incoming line side of the switch body is energized; when the button SB2 is pressed, RLY2 is attracted, indicating that the outgoing line side of the switch body is energized; when the buttons SB1 and SB2 are pressed simultaneously, RLY1 and RLY2 are attracted simultaneously, indicating that both sides of the switch body are energized.

[0040] When the line working environment simulation module 300 implements zero-voltage switching and zero-current switching, since the phases of the zero-sequence voltage and the zero-sequence current are the same as that of phase B, the present invention uses two self-locking switches SB7 and SB8 respectively connected to phase B to achieve this. When it is necessary to input the zero-sequence voltage, when the self-locking switch SB7 is pressed, the phase B voltage of the voltage three-phase inverter 130 is connected to the bus through SB7, and is connected to RLY4 representing the switch body through the normally open contacts of RLY1 and RLY2; when it is necessary to input the zero-sequence current, when the self-locking switch SB8 is pressed, the phase B current of the current three-phase inverter 140 is connected to the resistor R1 through SB8 and the normally open contact of RLY3, thereby forming a current. Finally, like the in-phase voltage and current, the zero-sequence voltage and current sampling are also output to the outside of the test platform through the banana socket and connected to the intelligent power distribution terminal.

[0041] When the switch body module 400 implements the point-by-point switch opening and closing control, as described above, the contacts of the circuit breaker are simulated by RLY3 and RLY4. The working mode of the real circuit breaker is to give a 30 - 100 ms electrical signal to the opening coil or the closing coil, and the circuit breaker releases the internal spring energy storage to perform opening and closing. In this platform, the double-coil magnetic latching relay RLY5 is used to achieve this. After the coil of RLY5 or the reset coil action is completed, the open / closed state of the contacts is maintained by the permanent magnet inside the relay, and further a clear opening and closing signal is given to RLY3 and RLY4. Perfectly simulating the working mode of the real circuit breaker.

[0042] When the switch body module 400 implements the functions of in-situ opening / closing buttons, remote / local switching, intuitive display of the switch states of in-situ opening / closing buttons, and electrical signal indication, it is implemented using an in-situ logic module. On the test platform, there is an opening button arranged to control the opening / closing actions of the circuit breaker body part of the test platform. There is a remote / local button arranged on the test platform. When it is placed in the remote position, the in-situ opening / closing buttons are ineffective, and only remote control (which can be an intelligent power distribution terminal) can be used; when placed in the local position, the remote control is ineffective, and only the in-situ opening / closing buttons can be used for operation. There are two LED indicators arranged on the test platform to indicate the working state of the circuit breaker. The red LED is used to represent that the simulated circuit breaker is in the closed position, and the green LED is used to represent that the simulated circuit breaker is in the open position. All the buttons on the test platform use indicators to indicate the working state of the buttons.

[0043] When the switch body module 400 realizes and sets the energy storage time, since in a real circuit breaker, after tripping, the energy storage motor drives the energy storage spring to store energy, and the circuit breaker cannot perform actions when the energy storage is not completed. The present invention simulates this characteristic using an integrated circuit. A red indicator light is used to display the energy storage state (defined as the non-energy-stored light). When the switch is opened, the non-energy-stored platform starts timing, the non-energy-stored light lights up, and the operation circuit is locked before the timing is completed, and no operation can be performed; after the timing is completed, the non-energy-stored light goes out and operations can be performed. The non-energy-stored time can be set. There is a knob arranged on the platform, that is, the non-energy-stored time adjustment knob, and the energy storage time can be set by turning the knob.

[0044] When the switch body module 400 simulates the faults of the switch, it mainly simulates "current flowing in the open position" in line faults and "switch refusal to operate" in switch body faults; The self-locking switch SB4 is used to implement the function of "current flowing in the open position", that is, when SB4 is turned on, RLY3 is driven by SB4, so that the current sampling signal is output to the outside of the test platform through the banana socket and connected to the intelligent power distribution terminal, thereby simulating the fault phenomenon of "current flowing in the open position"; The normally closed button SB3 for switch refusal to operate is used to implement the function of "switch refusal to operate". SB3 is normally closed. When SB3 is turned off, the power supply of RLY5 is cut off. Then, no matter what signal is given externally, RLY5 will not operate, thereby simulating the fault phenomenon of "switch refusal to operate".

[0045] By setting up the line power generation module 100, it can convert low-voltage direct current into three-phase four-wire alternating current simulating the actual working conditions of the analog distribution network terminal, providing power for devices such as the tested distribution terminal without the need for an additional power source; by setting up the line working environment simulation module 300 and the switch body module 400 electrically connected thereto, it can comprehensively simulate the actual working conditions of the primary switch. It is equivalent to moving the on-site environment to the laboratory. The two inverter modules inside simulate the power output of the low-voltage side of the substation and can simulate the situation of power coming from both sides of the primary switch; by setting up the port module 500, the connection port of the present invention with the distribution terminal covers all the functions of the real primary switch. For the distribution terminal, the present invention is a real circuit breaker. The interaction between the present invention and the operator not only includes the operation of the analog circuit breaker but also the operation of the line working conditions; by integrating all the modules required for testing into a circuit board and placing it in the secondary terminal equipment of the distribution network, the portability of the present invention can be improved and the cost can be reduced; the present invention has the characteristics of high integration and light weight, low cost, comprehensive functions for testing the characteristics of the secondary terminal equipment of the distribution network, and strong applicability, which can greatly improve the popularity rate.

[0046] Referring to Figure 1 and Figure 2 , further, in some embodiments of the present invention, the line power generation module includes: A DC power supply 110 for providing line power and control power; A single-chip microcomputer 120, electrically connected to the DC power supply, for receiving and adjusting the line power; A voltage three-phase inverter 130, the input end of the voltage three-phase inverter is electrically connected to the single-chip microcomputer 120, and the output end is electrically connected to the line working environment simulation module, for converting the line power into three-phase AC voltage and outputting it to the line working environment simulation module; A current three-phase inverter 140, the input end of the current three-phase inverter 140 is electrically connected to the single-chip microcomputer, and the output end is electrically connected to the switch body module, for converting the line power into three-phase AC current and outputting it to the switch body module; A voltage amplitude adjustment knob 150, electrically connected to the single-chip microcomputer 120; A current amplitude adjustment knob 160, electrically connected to the single-chip microcomputer 120; A frequency adjustment knob 170, electrically connected to the single-chip microcomputer 120.

[0047] Specifically, in this embodiment, the DC power supply 110 is used to supply power to the entire test platform, such as the DC bus power supply of the inverter and the internal control signal power supply. A buck DC / DC power supply chip is used to generate a 5V power supply and a 12V power supply respectively, which are used as the working power supplies for components such as the internal single-chip microcomputer, logic chip, and signal relay.

[0048] Two DC / AC modules (including a voltage three-phase inverter 130 and a current three-phase inverter 140) are respectively used to generate two groups of three-phase three-wire UVW signals with the same phase, which are respectively input into two independent SD-type transformers. After △-Y transformation, three-phase four-wire AC voltage ABCN is output. One of them is a power supply boosted to a maximum effective value of AC120V, which is used to simulate the output of a voltage transformer in a real scenario; the other is a power supply with a maximum effective value of AC6V generated by voltage reduction, and a small-value high-power resistor is respectively connected in series to form a current, which is used to simulate the output of a current transformer in a real scenario.

[0049] The voltage amplitude and frequency adjustment part (including a voltage amplitude adjustment knob 150, a current amplitude adjustment knob 160, and a frequency adjustment knob 170) belongs to an extended part of the two DC / AC modules. The amplitude and frequency requirements can be input to the single-chip microcomputer by means of a mechanical knob or a liquid crystal plus operation panel. The single-chip microcomputer 120 performs adjustment actions to change the output voltage amplitude.

[0050] By setting the line power generation module 100, low-voltage direct current can be converted into three-phase four-wire alternating current simulating the actual working conditions of the distribution network terminal, which can supply power to devices such as the tested distribution terminal and does not require an additional power supply.

[0051] Referring to Figure 1 and Figure 2 , further, in some embodiments of the present invention, the line working environment simulation module 300 includes: A first relay RLY1, the input end of the first relay RLY1 is electrically connected to the output end of the voltage three-phase inverter 130, and the output end of the first relay RLY1 is electrically connected to the input end of the switch body module 400. The first relay RLY1 is used to simulate the voltage input scenario on the incoming line side of the circuit breaker; A first self-locking button SB1, the first self-locking button SB1 is electrically connected to the control end of the first relay RLY1; A second relay RLY2, the input end of the second relay RLY2 is electrically connected to the output end of the voltage three-phase inverter 130, and the output end of the second relay RLY2 is electrically connected to the output end of the switch body module 400. The second relay RLY2 is used to simulate the voltage input scenario on the outgoing line side of the circuit breaker; The second self-locking button SB2, and the second self-locking button SB2 is electrically connected to the control terminal of the second relay RLY2.

[0052] Specifically, in this embodiment, when the line working environment simulation module 300 realizes the scenarios where the power input end is the incoming line side or the outgoing line side or both sides are powered, as Figure 2 shown, the normally open contacts at both ends of the relays RLY3 and RLY4 representing the switch body are respectively connected to the power bus through the normally open contacts of the relays RLY1 and RLY2, and finally the voltage sampling is output to the outside of the test platform through the banana socket and connected to the intelligent power distribution terminal. The self-locking buttons SB1 and SB2 respectively control the monostable relays RLY1 and RLY2. When the button SB1 is pressed, RLY1 is energized, indicating that the incoming line side of the switch body is powered; when the button SB2 is pressed, RLY2 is energized, indicating that the outgoing line side of the switch body is powered; when the buttons SB1 and SB2 are pressed simultaneously, RLY1 and RLY2 are energized simultaneously, indicating that both sides of the switch body are powered.

[0053] Refer to Figure 2 , further, in some embodiments of the present invention, the line working environment simulation module 300 further includes: The zero-voltage input / output self-locking switch SB7, one end of the zero-voltage input / output self-locking switch SB7 is electrically connected to one phase of the output end of the voltage three-phase inverter 130, and the other end of the zero-voltage input / output self-locking switch SB7 is electrically connected to the input ends of the first relay RLY1 and the second relay RLY2; The zero-current input / output self-locking switch SB8, one end of the zero-current input / output self-locking switch SB8 is electrically connected to one phase of the output end of the current three-phase inverter 140, and the other end of the zero-current input / output self-locking switch SB8 is electrically connected to the input end of the third relay RLY3.

[0054] Specifically, in this embodiment, when the line working environment simulation module 300 realizes zero-voltage input / output and zero-current input / output, since the phases of the zero-sequence voltage and the zero-sequence current are the same as that of the B phase, the present invention uses two self-locking switches SB7 and SB8 respectively connected to the B phase to achieve this. When it is necessary to input the zero-sequence voltage, when the self-locking switch SB7 is pressed, the B-phase voltage of the voltage three-phase inverter 130 is connected to the bus through SB7 and connected to RLY4 representing the switch body through the normally open contacts of RLY1 and RLY2; when it is necessary to input the zero-sequence current, when the self-locking switch SB8 is pressed, the B-phase current of the current three-phase inverter 140 is connected to the resistor R1 through SB8 and the normally open contact of RLY3, thereby forming a current. Finally, like the in-phase voltage and current, the zero-sequence voltage and current sampling are also output to the outside of the test platform through the banana socket and connected to the intelligent power distribution terminal.

[0055] Refer to Figure 2, Further, in some embodiments of the present invention, the switch body module 400 includes: A third relay RLY3, used to simulate a three-phase current circuit breaker. The input end of the third relay RLY3 is electrically connected to the current three-phase inverter 140, and the output end of the third relay RLY3 is electrically connected to the port module 500; A fourth relay RLY4, used to simulate a three-phase voltage circuit breaker. The input end of the fourth relay RLY4 is electrically connected to the output end of the first relay RLY1. The input end of the fourth relay RLY4 is also electrically connected to the port module 500. The output end of the fourth relay RLY4 is electrically connected to the output end of the second relay RLY2. The output end of the fourth relay RLY4 is also electrically connected to the port module 500; A fifth relay RLY5. The input end of the fifth relay RLY5 is electrically connected to the control power supply. The output end of the fifth relay RLY5 is electrically connected to the control ends of the third relay RLY3 and the fourth relay RLY4. The fifth relay RLY5 adopts a double-coil magnetic latching relay.

[0056] Specifically, in this embodiment, when the switch body module 400 realizes the point-by-point switch closing and opening control, as described above, the contacts of the circuit breaker are simulated by RLY3 and RLY4. The working mode of a real circuit breaker is to give a 30 - 100 ms electrical signal to the opening coil or closing coil, and the circuit breaker releases the internal spring energy storage to execute closing and opening. In this platform, a double-coil magnetic latching relay RLY5 is used to achieve this. After the coil action or the reset coil action of RLY5 is completed, the open / closed state of the contacts is maintained by the permanent magnet inside the relay, and further, a clear closing and opening signal is given to RLY3 and RLY4. It perfectly simulates the working mode of a real circuit breaker.

[0057] Refer to Figure 2 , Further, in some embodiments of the present invention, the switch body module 400 further includes: A local logic module. The output end of the local logic module is electrically connected to the control end of the fifth relay RLY5; A switch local closing button SB5, with one end electrically connected to the control power supply and the other end electrically connected to the input end of the local logic module; A switch local tripping button SB6, with one end electrically connected to the control power supply and the other end electrically connected to the input end of the local logic module; A remote / local switching button, with one end electrically connected to the control power supply and the other end electrically connected to the input end of the local logic module; A trip position with current button SB4, with one end electrically connected to the control power supply and the other end electrically connected to the control end of the third relay RLY3; The normally closed button SB3 for switch refusal to operate is electrically connected to the control power supply at one end and to the input end of the local logic module at the other end; The switch uncharged time adjustment knob is electrically connected to the input end of the local logic module; The switch uncharged indicator La3 is electrically connected to the output end of the local logic module.

[0058] Specifically, in this embodiment, when the switch body module 400 realizes the functions of local on-off buttons, remote / local switching, intuitive display of the switch state of local on-off buttons, and electrical signal indication, it is implemented by the local logic module. A trip button is arranged on the test platform to control the tripping / closing operation of the circuit breaker body part of the test platform. A remote / local button is arranged on the test platform. When it is placed in the remote position, the local on-off buttons are invalid, and only remote control (which can be an intelligent power distribution terminal) can be used; when it is placed in the local position, the remote control is invalid, and only the local on-off buttons can be used for operation. Two LED indicators are arranged on the test platform to indicate the working state of the circuit breaker. The red LED is used to represent that the simulated circuit breaker is in the closed position, and the green LED is used to represent that the simulated circuit breaker is in the open position. All the buttons on the test platform use indicators with lights to indicate the working state of the buttons.

[0059] When the switch body module 400 realizes and sets the energy storage time, since the real circuit breaker will have an energy storage motor driving the energy storage spring to store energy after tripping, the circuit breaker cannot perform an action when the energy storage is not completed. The present invention simulates this characteristic using an integrated circuit, and uses a red indicator La3 to display the energy storage state (defined as the uncharged lamp). When the switch trips, the uncharged platform starts timing, and the uncharged lamp La3 lights up. Before the timing is completed, the operation circuit is locked and no operation can be performed; after the timing is completed, the uncharged lamp La3 goes out and operations can be performed. The uncharged time can be set. A knob, that is, the uncharged time adjustment knob, is arranged on the platform, and the energy storage time can be set by turning the knob.

[0060] When the switch body module 400 simulates the switch faults, it mainly simulates "current flowing in the open position" in line faults and "switch refusal to operate" in switch body faults; The self-locking switch SB4 is used to realize the function of "current flowing in the open position", that is, when SB4 is turned on, RLY3 is driven by SB4, so that the current sampling signal is output to the outside of the test platform through the banana socket and connected to the intelligent power distribution terminal, thereby simulating the fault phenomenon of "current flowing in the open position"; The function of "switch refusal to operate" is realized by using the normally closed button SB3 of the switch. SB3 is normally closed. When SB3 is disconnected, the power supply of RLY5 is turned off. Then, regardless of what signals are given externally, RLY5 will not operate, thus simulating the fault phenomenon of "switch refusal to operate".

[0061] Refer to Figure 2 , further, in some embodiments of the present invention, the port module 500 includes: The incoming line voltage sampling socket (U01~Un1), which is electrically connected to the input end of the fourth relay RLY4 and is also used for electrically connecting to the secondary terminal of the distribution network; The outgoing line voltage sampling socket (U02~Un2), which is electrically connected to the output end of the fourth relay RLY4 and is also used for electrically connecting to the secondary terminal of the distribution network; The current sampling socket (I0~In), which is electrically connected to the output end of the third relay RLY3 and is also used for electrically connecting to the secondary terminal of the distribution network; The switch trip position telemetry terminal, which is electrically connected to the output end of the local logic module and is also used for electrically connecting to the secondary terminal of the distribution network; The switch close position telemetry terminal, which is electrically connected to the output end of the local logic module and is also used for electrically connecting to the secondary terminal of the distribution network; The switch remote closing terminal, which is electrically connected to the output end of the local logic module and is also used for electrically connecting to the secondary terminal of the distribution network; The switch remote tripping terminal, which is electrically connected to the output end of the local logic module and is also used for electrically connecting to the secondary terminal of the distribution network; The switch uncharged position terminal, which is electrically connected to the output end of the local logic module and is also used for electrically connecting to the secondary terminal of the distribution network.

[0062] Refer to Figure 1 and Figure 2 , further, in some embodiments of the present invention, a meter module 200 is also provided. The meter module 200 includes: The three-phase AC voltage meter 210, which is arranged between the voltage three-phase inverter 130 and the line working environment simulation module 300; The three-phase AC ammeter 220, which is arranged between the current three-phase inverter 140 and the switch body module 400.

[0063] The meter module 200 includes a three-phase AC voltage meter 210 and a three-phase AC ammeter 220, which are used to indicate the effective voltage value and effective current value of the analog voltage transformer and current transformer output by the voltage three-phase inverter 130 and the current three-phase inverter 140.

[0064] Refer to Figure 3 , Figure 4 andFigure 5 , the present invention also proposes a secondary terminal test device for a distribution network, including: A housing 700; An operation panel 600, which is arranged on one side of the housing and is used for electrically connecting with the secondary terminal of the distribution network; A circuit board module, which is arranged in the housing 700 and is electrically connected with the operation panel 600. The circuit board module is provided with a secondary terminal test circuit for the distribution network as described in any one of the above embodiments, and the operation panel is also used to adjust the working state of the circuit board module.

[0065] Specifically, in this embodiment, by integrating all the modules required for testing into a circuit board and placing them in the secondary terminal device of the distribution network, the portability of the present invention is improved and the cost is reduced. The housing 700 is surrounded by the operation panel 600, a front panel 710, two side panels 720, a rear panel 730 and a bottom panel 740 to form a cuboid hollow closed structure. The cavity is used for fixedly placing a circuit board module with a secondary terminal test circuit for the distribution network, and the front panel 710 is provided with a corner guard 711. The ports and knobs on the operation panel 600 are distributed as Figure 5 shown. The operation panel 600 is fixedly provided with foot pads 620 and panel anti-collision bars 610, so as to prevent accidental touch and misoperation, and at the same time improve the portability of the device. A three-phase AC voltmeter 210 and a three-phase AC ammeter 220 are also fixedly installed on the operation panel, which can conveniently observe the effective voltage value and effective current value of the current bus from the outside.

[0066] Referring to Figure 4 , further, in some embodiments of the present invention, the circuit board module includes: An operation panel PCB 810, which is electrically connected with the operation panel 600, and the operation panel PCB 810 is provided with a port module 500; A DC power supply 110 and an inverter control board 820, which are electrically connected with the operation panel PCB 810, and the DC power supply 110 and the inverter control board 820 are used to form a line power generation module 100; A main control board 830, which is electrically connected with the DC power supply 110 and the inverter control board 820, and is also electrically connected with the operation panel PCB 810. The main control board 830 is provided with a line working environment simulation module 300 and a switch body module 400.

[0067] Specifically, in this embodiment, the main control board 830 and the three-phase transformer 831 are fixed on the bottom panel 740. The operation panel PCB 810 and the operation panel 600 are fixedly connected by screws. The DC power supply 110 can convert AC into DC energy storage, which is convenient for charging the device and improves the applicability of the device. The inverter control board 820 and the main control board 830 are electrically connected through socket terminals.

[0068] The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the art. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A distribution network secondary terminal test circuit, characterized in that: include: A line power generation module, used for providing three-phase power; A line working environment simulation module is electrically connected to the line power generation module, and is used to simulate several input scenarios of the three-phase power supply, and is also used to realize the zero-sequence voltage input or output and zero-sequence current input or output functions; A switch body module, electrically connected to the line working environment simulation module and also electrically connected to the line power generation module, for simulating the working state and fault condition of the circuit breaker; The port module is electrically connected to the switch body module and is also used to be electrically connected to the secondary terminal of the distribution network.

2. The power distribution network secondary terminal test circuit according to claim 1, characterized in that: The line power generation module comprises: DC power supply, used to provide line power and control power; A single chip microcomputer, the single chip microcomputer is electrically connected to the DC power supply and is used to receive and adjust the line power supply; A voltage three-phase inverter, the input end of which is electrically connected to the single-chip computer, and the output end of which is electrically connected to the line working environment simulation module, for converting the line power into a three-phase AC voltage and outputting it to the line working environment simulation module; A current three-phase inverter, the input end of which is electrically connected to the single-chip microcomputer, and the output end of which is electrically connected to the switch body module, for converting the line power into a three-phase alternating current and outputting it to the switch body module; A voltage amplitude adjustment knob electrically connected to the single chip computer; A current amplitude adjustment knob electrically connected to the single chip computer; The frequency adjustment knob is electrically connected to the single chip computer.

3. The power distribution network secondary terminal test circuit according to claim 2, characterized in that: The line working environment simulation module includes: A first relay, wherein an input end of the first relay is electrically connected to an output end of the voltage three-phase inverter, an output end of the first relay is electrically connected to an input end of the switch body module, and the first relay is used to simulate a voltage input scenario on the incoming line side of the circuit breaker; A first self-locking button, wherein the first self-locking button is electrically connected to a control end of the first relay; a second relay, wherein an input end of the second relay is electrically connected to an output end of the voltage three-phase inverter, an output end of the second relay is electrically connected to an output end of the switch body module, and the second relay is used to simulate a voltage input scenario on the outgoing line side of the circuit breaker; A second self-locking button, wherein the second self-locking button is electrically connected to the control end of the second relay.

4. The power distribution network secondary terminal test circuit according to claim 3, characterized in that: The line working environment simulation module also includes: A zero-voltage throw-in / out self-locking switch, one end of which is electrically connected to one phase of the output end of the voltage three-phase inverter, and the other end of which is electrically connected to the input end of the first relay and the input end of the second relay; A zero-current throw-in / out self-locking switch, one end of which is electrically connected to one phase of the output end of the current three-phase inverter, and the other end of which is electrically connected to the switch body module.

5. The power distribution network secondary terminal test circuit according to claim 3, characterized in that: The switch body module comprises: A third relay, used for simulating a three-phase current circuit breaker, wherein an input end of the third relay is electrically connected to the current three-phase inverter, and an output end of the third relay is electrically connected to the port module; a fourth relay, used to simulate a three-phase voltage circuit breaker, wherein the input end of the fourth relay is electrically connected to the output end of the first relay, the input end of the fourth relay is also electrically connected to the port module, the output end of the fourth relay is electrically connected to the output end of the second relay, and the output end of the fourth relay is also electrically connected to the port module; A fifth relay, wherein the input end of the fifth relay is electrically connected to the control power supply, the output end of the fifth relay is electrically connected to the control end of the third relay and the control end of the fourth relay, and the fifth relay is a double-coil magnetic latching relay.

6. The power distribution network secondary terminal test circuit according to claim 5, characterized in that: The switch body module also includes: A local logic module, wherein an output end of the local logic module is electrically connected to a control end of the fifth relay; A switch local closing button, one end of which is electrically connected to the control power supply, and the other end of which is electrically connected to the input end of the local logic module; A switch local trip button, one end of which is electrically connected to the control power supply, and the other end of which is electrically connected to the input end of the local logic module; A remote / local switching button, one end of which is electrically connected to the control power supply, and the other end of which is electrically connected to the input end of the local logic module; A jump position flow button, one end of which is electrically connected to the control power supply, and the other end of which is electrically connected to the control end of the third relay; A switch-rejection normally closed button, one end of which is electrically connected to the control power supply, and the other end of which is electrically connected to the input end of the local logic module; The switch un-energy storage time adjustment knob is electrically connected to the input end of the local logic module; The switch no energy storage indicator light is electrically connected to the output end of the local logic module.

7. The power distribution network secondary terminal test circuit according to claim 6, characterized in that: The port module comprises: An incoming line voltage sampling socket, electrically connected to the input end of the fourth relay, and also used to be electrically connected to the secondary terminal of the distribution network; An outlet voltage sampling socket, electrically connected to the output end of the fourth relay, and also used to be electrically connected to the secondary terminal of the distribution network; A current sampling socket, electrically connected to the output end of the third relay, and also used to be electrically connected to the secondary terminal of the power distribution network; A switch trip remote signal terminal, electrically connected to the output end of the local logic module, and also used to be electrically connected to the secondary terminal of the distribution network; A switch closing position remote signal terminal, electrically connected to the output end of the local logic module, and also used to be electrically connected to the secondary terminal of the distribution network; A remote closing terminal of the switch is electrically connected to the output end of the local logic module and is also used to be electrically connected to the secondary terminal of the distribution network; A switch remote tripping terminal, electrically connected to the output end of the local logic module, and also used to be electrically connected to the secondary terminal of the distribution network; The switch non-energy storage position terminal is electrically connected to the output end of the local logic module and is also used to be electrically connected to the secondary terminal of the distribution network.

8. The power distribution network secondary terminal test circuit according to claim 2, characterized in that: A meter module is also provided, and the meter module comprises: A three-phase AC voltmeter, arranged between the voltage three-phase inverter and the line working environment simulation module; A three-phase AC ammeter is arranged between the current three-phase inverter and the switch body module.

9. A distribution network secondary terminal test device, characterized in that: include: case; An operation panel, the operation panel is arranged on one side of the housing and is used to be electrically connected to the secondary terminal of the distribution network; A circuit board module, wherein the circuit board module is arranged in the shell and is electrically connected to the operation panel. The circuit board module is provided with a distribution network secondary terminal test circuit as described in any one of claims 1 to 8. The operation panel is also used to adjust the working state of the circuit board module.

10. The distribution network secondary terminal test equipment according to claim 9, characterized in that: The circuit board module comprises: An operation panel PCB, the operation panel PCB is electrically connected to the operation panel, and the operation panel PCB is provided with a port module; A DC power supply and an inverter control board are electrically connected to the operation panel PCB, and the DC power supply and the inverter control board are used to form a line power generation module; The main control board is electrically connected to the power supply and the inverter control board, and is also electrically connected to the operation panel PCB. The main control board is provided with a line working environment simulation module and a switch body module.

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