Mechanical switch rated closing current test system

Abstract

The invention provides a rated closing current test system for a mechanical switch. The rated closing current test system comprises a current source, a through-current branch and a control module. And the through-current branch is connected in series with the current source after being connected in parallel with the mechanical switch. The control module can be connected with a current source and can also be connected with a mechanical switch. The control module is used for controlling the current source and controlling the mechanical switch to be switched off or switched on. When the mechanical switch is in an off state, the current source is used for providing current for the through-flow branch. When the mechanical switch is in a closed state, the current source is used for providing current for the mechanical switch. When the mechanical switch is in a closed state, the current flowing through the through-flow branch can be rapidly transferred to the mechanical switch, which accords with the actual rapid current transfer working condition, and the rated closing current test requirement of the mechanical switch is met. The test system provided by the invention does not need to be provided with a resistor as a load, and greatly reduces the electric energy loss in the test process of the rated closing current of the mechanical switch.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a mechanical switch rated closing current testing system. Background Art

[0002] With the development of flexible DC transmission technology, higher requirements are placed on the reliability of the operation of flexible DC converter valves. The submodules in the flexible DC converter valve include capacitors, power tubes, control boards, mechanical switches and thyristors. When a single submodule fails, the mechanical switch can bypass the submodule to ensure that the flexible DC converter valve continues to operate. If the mechanical switch fails to operate, the flexible DC converter valve will stop operating.

[0003] During the operation of the flexible DC converter valve, a failure in a submodule will trigger the mechanical switch. At this time, the current in the bridge arm of the flexible DC converter valve is usually large. Because the impedance of the mechanical switch is small (usually tens of μΩ), the bridge arm current will be instantly transferred to the mechanical switch when the moving contact and the static contact of the mechanical switch touch. Compared with zero-current closing, a larger electric repulsion force will be generated, affecting the closing reliability of the mechanical switch.

[0004] In order to verify the closing ability of the mechanical switch under the rated current, it is necessary to perform a rated closing current test on the mechanical switch. The related technology often uses a generator as a power supply. After the mechanical switch is closed, due to the influence of the generator and the inductor, the current will not change suddenly, but will rise slowly from zero to the rated current, which is inconsistent with the rapid current transfer condition in actual field applications. In addition, the current of the generator is an unbiased sinusoidal current, which is inconsistent with the AC and DC superimposed current in the bridge arm current. Therefore, the electrical stress of the test system provided by the related technology is not equivalent to the electrical stress of the submodule during an actual field fault, and cannot meet the rated closing current test requirements of the mechanical switch. Summary of the invention

[0005] In order to solve the problem of meeting the requirements of the rated closing current test of a mechanical switch in the prior art, the present application provides a mechanical switch rated closing current test system, which may include: a current source, a current branch and a control module. The current branch is connected in parallel with the mechanical switch and then in series with the current source. The control module may be connected to the current source and may also be connected to the mechanical switch.

[0006] The control module is used to control the current source and control the mechanical switch to open or close.

[0007] The current source is used to: when the mechanical switch is in an open state, provide current to the current-carrying branch under the control of the control module; and when the mechanical switch is in a closed state, provide current to the mechanical switch under the control of the control module.

[0008] It is conceivable that when the mechanical switch is in a closed state, the current flowing through the current-carrying branch can be transferred to the mechanical switch.

[0009] Optionally, the current-passing branch includes anti-parallel semiconductor devices, wherein the semiconductor devices may be diodes or thyristors, etc. Alternatively, the current-passing branch includes a power tube.

[0010] In some possible implementations, the current source includes a direct current source and / or an alternating current source. When the current source includes a direct current source and an alternating current source, the direct current source is connected in parallel with the alternating current source.

[0011] That is, the current source may include only a direct current source, or the current source may include only an alternating current source, or the current source may include both a direct current source and an alternating current source.

[0012] The DC current source is used to provide a DC current to a flow branch or a mechanical switch under the control of a control module.

[0013] The AC current source is used to provide AC current to the current-carrying branch or the mechanical switch under the control of the control module.

[0014] In some other possible implementations, the mechanical switch rated closing current test system further includes a first acquisition module and a second acquisition module, wherein the first acquisition module is connected in series with the current-carrying branch, the second acquisition module is connected in series with the mechanical switch, and both the first acquisition module and the second acquisition module are connected to the control module.

[0015] The first acquisition module is used to: under the control of the control module, acquire the direct current and / or alternating current flowing through the current branch and transmit it to the control module.

[0016] The second acquisition module is used to: under the control of the control module, collect the direct current and / or alternating current flowing through the mechanical switch and transmit it to the control module.

[0017] Optionally, the first acquisition module and the second acquisition module may be current sensors, etc., which is not limited in this application.

[0018] In some other possible implementations, the control module includes a control unit, a first DC voltage source, a first capacitor component, and a first drive unit. The first DC voltage source is connected in parallel with the first capacitor component and then in series with the first drive unit. The control unit is connected to the first drive unit, and the first drive unit is also connected to the mechanical switch. The current source, the first acquisition module, and the second acquisition module are all connected to the control unit.

[0019] The control unit is used to control the first drive unit so that the first drive unit drives the mechanical switch to open or close.

[0020] Optionally, the first DC voltage source is used to charge the first capacitor component when the mechanical switch is in an off state.

[0021] The control unit is specifically used to determine the closing time of the mechanical switch according to the phase of the alternating current, and control the first driving unit to transmit the electric energy released by the first capacitor component to the mechanical switch according to the closing time, so as to close the mechanical switch.

[0022] Furthermore, the control module also includes a first detection unit, the first detection unit is connected to the mechanical switch, and the first detection unit is also connected to the control unit.

[0023] The first detection unit is used to detect the state of the micro switch in the mechanical switch under the control of the control unit, and determine the state of the mechanical switch according to the state of the micro switch.

[0024] The control unit is also used to determine whether the mechanical switch is completely closed within a preset time range according to the state of the mechanical switch.

[0025] Exemplarily, the mechanical switch rated closing current test system further includes a first circuit breaker and / or a second circuit breaker. The first circuit breaker and / or the second circuit breaker are connected to the control module, the first circuit breaker is connected in series with a DC current source, and the second circuit breaker is connected in series with an AC current source.

[0026] The control module is also used to: detect the state of the first circuit breaker and / or the second circuit breaker, and when the first circuit breaker and / or the second circuit breaker is in a closed state, send a first control signal to the first circuit breaker, and / or send a second control signal to the second circuit breaker.

[0027] The first circuit breaker is used to perform on-off control and protection on the DC current source according to the first control signal.

[0028] The second circuit breaker is used to perform on-off control and protection on the AC current source according to the second control signal.

[0029] Compared with the prior art, the beneficial effects of this application are:

[0030] The mechanical switch rated closing current test system provided in the present application may include a current source, a current branch and a control module. Among them, the current branch is connected in parallel with the mechanical switch and then in series with the current source. The control module can be connected to the current source and can also be connected to the mechanical switch. The control module is used to control the current source and control the mechanical switch to open or close. The current source is used to provide current to the current branch under the control of the control module when the mechanical switch is in an open state. The current source is also used to provide current to the mechanical switch under the control of the control module when the mechanical switch is in a closed state. It can be seen that when the mechanical switch is in a closed state, the current flowing through the current branch can be quickly transferred to the mechanical switch, which is consistent with the actual rapid current transfer operating condition, thereby meeting the rated closing current test requirements of the mechanical switch.

[0031] The current source of the present application can provide an AC current with a DC bias that is consistent with the bridge arm current of the flexible DC converter valve in actual field applications through an AC current source and a DC current source, that is, a current that is a superposition of AC current and DC current is provided through an AC current source and a DC current source, further ensuring that the test system meets the rated closing current test requirements of the mechanical switch.

[0032] The test system provided in the present application can quickly transfer the current from the current-carrying branch to the mechanical switch at the moment the mechanical switch is closed. The electrical stress is equivalent to the electrical stress of the sub-module during an actual field failure, further ensuring that the test system meets the rated closing current test requirements of the mechanical switch.

[0033] In the present application, the control unit can determine the closing time of the mechanical switch according to the phase of the AC current, can select the test of the maximum stress working condition of the mechanical switch, and can realize multiple tests of the mechanical switch under the same working condition.

[0034] The test system provided in the present application does not need to set a resistor as a load, which greatly reduces the power loss during the rated closing current test of the mechanical switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0036] Figure 1 A schematic structural diagram of a mechanical switch rated closing current test system in an embodiment of the present application;

[0037] Figure 2a is a schematic structural diagram of a flow branch in an embodiment of the present application;

[0038] Figure 2b is a schematic structural diagram of a flow branch in an embodiment of the present application;

[0039] Figure 2c is a schematic structural diagram of a flow branch in an embodiment of the present application;

[0040] Figure 3 A schematic structural diagram of a mechanical switch rated closing current test system in an embodiment of the present application;

[0041] Figure 4 It is a schematic structural diagram of a mechanical switch rated closing current testing system in an embodiment of the present application. DETAILED DESCRIPTION

[0042] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0043] The terms "first", "second", etc. in the specification embodiments, claims, and drawings of the present application are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, including a series of steps or units. The method, system, product, or device is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or devices.

[0044] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0045] The embodiment of the present application provides a mechanical switch rated closing current test system. The mechanical switch may include a first coil and a second coil, and may also include a first micro switch and a second micro switch. The specific introduction of the mechanical switch can be referred to in the relevant literature, and the embodiment of the present application will not be described in detail.

[0046] like Figure 1 As shown, the mechanical switch rated closing current test system 100 includes a current source 10, a current branch 20 and a control module 30. The current branch 20 is connected in parallel with the mechanical switch K and then connected in series with the current source 10. The control module 30 can be connected to the current source 10 and can also be connected to the mechanical switch K.

[0047] The control module 30 is used to control the current source 10 and control the mechanical switch K to open or close.

[0048] The current source 10 is used to provide current to the flow branch 20 under the control of the control module 30 when the mechanical switch K is in the open state, and is also used to provide current to the mechanical switch K under the control of the control module 30 when the mechanical switch K is in the closed state.

[0049] It is conceivable that when the mechanical switch K is in a closed state, the current flowing through the current branch 20 can be transferred to the mechanical switch K.

[0050] Optionally, the current branch 20 includes anti-parallel semiconductor devices. The semiconductor devices may be diodes or thyristors. Figure 2a As shown, the current branch 20 includes anti-parallel diodes. Figure 2b As shown, the current branch 20 includes anti-parallel thyristors. Figure 2c As shown, the flow branch 20 may include a power tube Q.

[0051] In some possible implementations, such as Figure 3 As shown, the current source 10 includes a DC current source 11 and / or an AC current source 12. When the current source 10 includes the DC current source 11 and the AC current source 12, the DC current source 11 and the AC current source 12 are connected in parallel.

[0052] That is, the current source 10 may include only the DC current source 11, or the current source 10 may include only the AC current source 12. Alternatively, the current source 10 may include the DC current source 11 and the AC current source 12. In the embodiment of the present application, the current source 10 may include the DC current source 11 and the AC current source 12 as an example.

[0053] The DC current source 11 is used to provide a DC current to the flow branch 20 or the mechanical switch K under the control of the control module 30 .

[0054] The alternating current source 12 is used to provide an alternating current to the flow branch 20 or the mechanical switch K under the control of the control module 30 .

[0055] In some other possible implementations, the mechanical switch rated closing current test system 100 further includes a first acquisition module 40 and a second acquisition module 50. The first acquisition module 40 is connected in series with the current branch 20, the second acquisition module 50 is connected in series with the mechanical switch K, and both the first acquisition module 40 and the second acquisition module 50 are connected to the control module 30.

[0056] The first acquisition module 40 is used to: under the control of the control module 30, collect the DC current and / or AC current flowing through the flow branch 20 and transmit it to the control module 30 (which can be Figure 3 The control unit 31 of the control module 30).

[0057] The second acquisition module 50 is used to: under the control of the control module 30, collect the DC current and / or AC current flowing through the mechanical switch K and transmit it to the control module 30 (which can be Figure 3 The control unit 31 of the control module 30).

[0058] Optionally, the first acquisition module 40 and the second acquisition module 50 may be current sensors, etc., and the present application is not limited to the embodiments.

[0059] In some other possible implementations, such as Figure 3 As shown, the control module 30 includes a control unit 31, a first DC voltage source 32, a first capacitor assembly 33 (which may include multiple capacitors, and the capacitance is adjustable) and a first drive unit 34. The first DC voltage source 32 is connected in parallel with the first capacitor assembly 33 and then connected in series with the first drive unit 34. The control unit 31 is connected to the first drive unit 34, and the first drive unit 34 is also connected to the mechanical switch K (which may be the first coil of the mechanical switch K). The current source 10, the first acquisition module 40 and the second acquisition module 50 are all connected to the control unit 31.

[0060] The control unit 31 is used to control the first driving unit 34 so that the first driving unit 34 drives the mechanical switch K to open or close.

[0061] Optionally, the first DC voltage source 32 is used to charge the first capacitor component 33 when the mechanical switch K is in the disconnected state. That is, when the mechanical switch K is in the disconnected state, the first DC voltage source 32 can provide an adjustable charging voltage for the first capacitor component 33 to charge the first capacitor component 33. When the voltage of the first capacitor component 33 reaches a preset voltage threshold, the first capacitor component 33 stops charging.

[0062] The control unit 31 is specifically used to determine the closing time of the mechanical switch K according to the phase of the AC current, and control the first drive unit 34 to transmit the electric energy released by the first capacitor component 33 to the mechanical switch K according to the closing time, so as to close the mechanical switch K. The control unit 31 is also used to control the DC current source 11 and / or the AC current source 12, and specifically can control the start and stop of the DC current source 11 and / or the AC current source 12, as well as the amplitude of the DC current output by the DC current source 11 and / or the phase and amplitude of the AC current output by the AC current source 12.

[0063] It is conceivable that the control unit 31 can set the trigger signal advance amount according to the actual action time of the mechanical switch K, trigger the mechanical switch K in advance, and make the current phase at the moment of closing the mechanical switch K be in a preset current phase. When the mechanical switch K is closed, because the resistance of the mechanical switch K is usually tens of μΩ, the on-state voltage drop of the diode in the current branch 20 is about 1V, and the current flowing through the current branch 20 will be quickly transferred to the mechanical switch K.

[0064] After the control unit 31 sends out a trigger signal, if no feedback of the closed state of the mechanical switch K is detected within a preset time, it indicates that the mechanical switch K refuses to move, and the control unit 31 sends out a stop signal, and the DC current source 11 and the AC current source 12 stop. If the feedback of the closed state of the mechanical switch K is detected within the preset time, it indicates that the mechanical switch K is closed normally. When the current flow time after the mechanical switch K is closed reaches the preset time, the AC current source 12 and the DC current source 11 stop, and the current of the mechanical switch K drops to 0.

[0065] Further, such as Figure 3 As shown, the control module 30 further includes a first detection unit 35 , which is connected to the mechanical switch K (which may be a first micro switch), and is also connected to the control unit 31 .

[0066] The first detection unit 35 is used to: under the control of the control unit 31, detect the state of the micro switch (which may be the first micro switch) in the mechanical switch K, and determine the state of the mechanical switch K according to the state of the micro switch (which may be the first micro switch).

[0067] The control unit 31 is further used to determine whether the mechanical switch K is closed within a preset time range according to the state of the mechanical switch K, that is, to determine whether the mechanical switch K is closed successfully within the preset time range.

[0068] So, if Figure 4As shown, the control module 30 may further include a second DC voltage source 36, a second capacitor assembly 37 (which may include multiple capacitors, and the capacitance is adjustable) and a second drive unit 38. The second DC voltage source 36 is connected in parallel with the second capacitor assembly 37 and then connected in series with the second drive unit 38, the control unit 31 is connected with the second drive unit 38, and the second drive unit 38 is also connected with the mechanical switch K (which may be the second coil of the mechanical switch K).

[0069] For further reference, Figure 4 The control module 30 may further include a second detection unit 39 , which is connected to the mechanical switch K (which may be a second micro switch), and the second detection unit 39 is also connected to the control unit 31 .

[0070] The first detection unit 35 is used to: under the control of the control unit 31, detect the state of the micro switch (which can be the second micro switch) in the mechanical switch K, and determine the state of the mechanical switch K according to the state of the micro switch (which can be the second micro switch).

[0071] The control unit 31 is further used to determine whether the mechanical switch K is closed within a preset time range according to the state of the mechanical switch K, that is, to determine whether the mechanical switch K is closed successfully within the preset time range.

[0072] Exemplary, reference Figure 4 The mechanical switch rated closing current test system 100 further includes a first circuit breaker QF1 and / or a second circuit breaker QF2. The first circuit breaker QF1 and / or the second circuit breaker QF2 are connected to the control module 30. The first circuit breaker QF1 is connected in series with the DC current source 11, and the second circuit breaker QF2 is connected in series with the AC current source 12.

[0073] The control module 30 is also used to: detect the state of the first circuit breaker QF1 and / or the second circuit breaker QF2, and when the first circuit breaker QF1 and / or the second circuit breaker QF2 is in a closed state, send a first control signal to the first circuit breaker QF1, and / or send a second control signal QF2 to the second circuit breaker.

[0074] The first circuit breaker QF1 is used to: perform on-off control and protection on the DC current source 11 according to the first control signal. Specifically, the first end of the first circuit breaker QF1 can be connected to the positive end of the DC current source 11, and the second end of the first circuit breaker QF1 can be connected to the first acquisition module 40 and the second acquisition module 50. The negative end of the DC current source 11 can be grounded. Similarly, the first end of the second circuit breaker QF2 can be connected to the first end of the AC current source 12, and the second end of the second circuit breaker QF2 can be connected to the first acquisition module 40 and the second acquisition module 50. The second end of the AC current source 12 can be grounded.

[0075] The second circuit breaker QF2 is used to perform on-off control and protection on the AC current source 12 according to the first control signal.

[0076] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. A mechanical switch rated closing current test system, characterized in that: It includes a current source, a flow branch and a control module; wherein the flow branch is connected in parallel with the mechanical switch and then connected in series with the current source; the control module is connected with the current source, and the control module is also connected with the mechanical switch; The control module is used to: control the current source and control the mechanical switch to open or close; The current source is used to: provide current to the current-carrying branch under the control of the control module when the mechanical switch is in an open state; and to provide current to the mechanical switch under the control of the control module when the mechanical switch is in a closed state.

2. The mechanical switch rated closing current test system according to claim 1, characterized in that: The current-passing branch includes anti-parallel semiconductor devices; wherein the semiconductor devices are diodes or thyristors.

3. The mechanical switch rated closing current test system according to claim 1, characterized in that: The current-passing branch includes a power tube.

4. The mechanical switch rated closing current test system according to claim 1, characterized in that: The current source includes a direct current source and / or an alternating current source; When the current source includes the direct current source and the alternating current source, the direct current source is connected in parallel with the alternating current source; The DC current source is used to: provide a DC current to the current-passing branch or the mechanical switch under the control of the control module; The alternating current source is used to provide alternating current to the current-carrying branch or the mechanical switch under the control of the control module.

5. The mechanical switch rated closing current test system according to claim 4, characterized in that: The mechanical switch rated closing current test system further includes a first acquisition module and a second acquisition module; wherein the first acquisition module is connected in series with the current-carrying branch, the second acquisition module is connected in series with the mechanical switch, and both the first acquisition module and the second acquisition module are connected to the control module; The first acquisition module is used to: under the control of the control module, acquire the direct current and / or the alternating current flowing through the flow branch and transmit the acquisition to the control module; The second acquisition module is used to: under the control of the control module, acquire the direct current and / or the alternating current flowing through the mechanical switch and transmit the acquisition to the control module.

6. The mechanical switch rated closing current test system according to claim 5, characterized in that: The control module includes a control unit, a first DC voltage source, a first capacitor component and a first driving unit; Wherein, after the first DC voltage source is connected in parallel with the first capacitor component, it is connected in series with the first driving unit, the control unit is connected with the first driving unit, and the first driving unit is also connected with the mechanical switch; the current source, the first acquisition module and the second acquisition module are all connected with the control unit; The control unit is used to control the first driving unit so that the first driving unit drives the mechanical switch to open or close.

7. The mechanical switch rated closing current test system according to claim 6, characterized in that: The first DC voltage source is used to charge the first capacitor component when the mechanical switch is in an off state; The control unit is specifically used to determine the closing time of the mechanical switch according to the phase of the alternating current, and control the first driving unit to transmit the electric energy released by the first capacitor component to the mechanical switch according to the closing time, so as to close the mechanical switch.

8. The mechanical switch rated closing current test system according to claim 6, characterized in that: The control module further includes a first detection unit, the first detection unit is connected to the mechanical switch, and the first detection unit is connected to the control unit; The first detection unit is used to: under the control of the control unit, detect the state of the micro switch in the mechanical switch, and determine the state of the mechanical switch according to the state of the micro switch; The control unit is further used to determine whether the mechanical switch is closed within a preset time range according to the state of the mechanical switch.

9. The mechanical switch rated closing current test system according to claim 4, characterized in that: The mechanical switch rated closing current test system further includes a first circuit breaker and / or a second circuit breaker; the first circuit breaker and / or the second circuit breaker are connected to the control module, the first circuit breaker is connected in series with the DC current source, and the second circuit breaker is connected in series with the AC current source; The control module is further used to: detect the state of the first circuit breaker and / or the second circuit breaker, and when the first circuit breaker and / or the second circuit breaker is in a closed state, send a first control signal to the first circuit breaker, and / or send a second control signal to the second circuit breaker; The first circuit breaker is used to: perform on-off control and protection on the DC current source according to the first control signal; The second circuit breaker is used to perform on-off control and protection on the AC current source according to the second control signal.

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