Method for replacing mechanical switch with semiconductor device

Abstract

The invention discloses a method for replacing a mechanical switch with a semiconductor device, which relates to the field of electronic switches, and is characterized in that in a high-voltage direct-current system, a branch circuit where the semiconductor device is located runs with a load, the other branch circuit is an open-circuit load branch circuit, and the semiconductor device comprises an MOS (Metal Oxide Semiconductor) tube switching circuit; when an external digital signal is connected, the digital signal passes through the level conversion circuit and the gate drive circuit and controls the control end of the MOS tube switching circuit to be powered off, and when the control end is powered off, a loaded branch where the semiconductor device is located stays in a closed-circuit state and then is delayed to be disconnected. And the load of the other branch circuit begins to be reduced until the load value is reduced to be within the conduction threshold range, and the open-circuit load branch circuit is changed into a conduction state. On-off can be completely achieved without obstacles under the on-load condition, the effectiveness of the switch is guaranteed, and the safety and reliability of a direct-current high-voltage system are greatly improved.

Description

Technical Field

[0001] The invention relates to the field of electronic switches, and in particular to a method for replacing a mechanical switch with a semiconductor device. Background Art

[0002] DC contactors are prone to arcing when shutting off power with current; Arcing may occur during the switching process of the contactor. When the contactor disconnects the circuit, the current can only be realized by the air gap or dielectric gap between the electrodes that are too close, forming an arc. The arcing problem of the contactor is often caused by the arc not being extinguished in time.

[0003] Therefore, there is an urgent need for a method of replacing mechanical switches with semiconductor devices to solve the problem of any arcing. Summary of the invention

[0004] The present invention discloses a method for replacing a mechanical switch with a semiconductor device, which solves the problems of the prior art.

[0005] In a first aspect, the present invention provides a method for replacing a mechanical switch with a semiconductor device, comprising: in a high voltage direct current system, a branch where the semiconductor device is located is operated with a load, and another branch is an open-circuit load branch, the semiconductor device comprises a MOS tube switch circuit, When an external digital signal is connected, the digital signal controls the control end of the MOS tube switch circuit to be powered off through the level conversion circuit and the gate drive circuit. When the control end is powered off, the load branch where the semiconductor device is located remains in the path state and then delays disconnection, and the load of the other branch begins to decrease until the load value is reduced to within the conduction threshold range, and the disconnected load branch becomes conductive.

[0006] Furthermore, in the high-voltage DC system, the original conduction signal is output through the branch where the semiconductor device with the load is located. After receiving the external digital signal, the delay time of the branch where the semiconductor device with the load is located is less than the time from the load of the other branch starting to decrease until the load value is reduced to within the conduction threshold range.

[0007] Furthermore, the other branch does not work when the branch where the semiconductor device is located is running under load, and the other branch conducts current in the high-voltage DC system to electrically connect a subsequent circuit path when the branch where the semiconductor device is located is connected to a control signal disconnection under load.

[0008] Furthermore, the branch where the loaded semiconductor device is located is connected to an external digital signal control, and the disconnected load branch generates a DC pulse in the stage from the delayed disconnection to the load starting to reduce until the load value is reduced to the conduction threshold range, and the corresponding process of generating DC pulses is periodically controlled by an external digital signal.

[0009] Furthermore, the semiconductor device is arranged on a passage in a vacuum environment.

[0010] Furthermore, when the digital signal is periodically output to the MOS switch circuit, the branch where the semiconductor device is located outputs a DC pulse waveform.

[0011] Furthermore, when a single digital signal is output to a semiconductor device, the MOS tube switch circuit is connected to a high level and the other branch is delayed to be turned on, and the other branch is delayed to be turned on to provide a DC power supply for subsequent circuits, and the MOS tube switch circuit is connected to a high level as an electronic switch of the high-voltage DC system.

[0012] The present invention provides a method for replacing a mechanical switch with a semiconductor device, which can realize disconnection without any obstacles under load, ensure the effectiveness of the switch, and greatly improve the safety and reliability of the DC high voltage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of the present invention, and do not constitute a limitation of the embodiments of the present invention. In the drawings: Figure 1 A flow chart of a method for replacing a mechanical switch with a semiconductor device is provided according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0014] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0015] First, the terms involved in the present invention are explained: The electronic switch is developed to solve the problem of arcing in DC contactors when they are powered on and off. The basic principle is to use semiconductor switches to replace mechanical contacts, so that the contacts are in a closed vacuum environment. When the contacts are disconnected, the current will not excite the air to cause arcing. It is the best alternative to DC contactors. The electronic switch can achieve fast closing and shutting down under current without any arcing. When a pulse waveform needs to be output, the electronic switch can also be used to quickly shut down to generate a pulse power supply. It is the best solution for DC pulse power supply and can be widely used in DC power supply systems.

[0016] Arcing may occur during the switching process of the contactor. When the contactor disconnects the circuit, the current can only be realized by the air gap or dielectric gap between the electrodes that are too close, forming an arc. The arcing problem of the contactor is often caused by the arc not being extinguished in time.

[0017] The working principle of the contactor is that when the coil is de-energized, the electromagnetic attraction of the static iron core disappears, the reaction force of the spring separates the moving iron core from the static iron core, and the three moving contact pieces of the contact system move, causing the main contact to disconnect, the auxiliary normally closed contact to close, the auxiliary normally open contact to disconnect, and the power supply to be cut off. The principle of closing the main circuit: turn on the power → energize the coil → generate magnetic flux in the iron core → generate electromagnetic attraction → electromagnetic attraction overcomes the spring force → attracts the armature → the contact mechanism moves → the main contact closes → the main circuit is connected.

[0018] The arc lasts too long: During the opening and closing operation of the contactor, when the arc lasts too long, it is easy to cause damage or burning of materials and other components inside the contactor, and it may also cause other electrical faults.

[0019] Switch capacity mismatch: If the contactor switch capacity is too small or the electrical load is too large, it is easy to cause the voltage or current to be too high, which in turn causes the contactor to arc.

[0020] Thermal expansion and contraction: With the long-term use of the contactor, the internal components will experience thermal expansion and contraction, viscosity and other phenomena, causing the mechanism to become stuck or even unable to work normally.

[0021] Insufficient or excessive contact pressure of the contactor: The contact pressure of the contactor directly affects its conduction performance. If the contact pressure is insufficient or excessive, it is easy to cause switch failure or arcing.

[0022] Contactor surface contamination: The presence of contaminants such as iron filings, oxides or dust on the surface of the contactor will cause the contact pressure to decrease, which will also cause arcing.

[0023] The specific application scenario of the present invention is the original mechanical switch replacement application scenario.

[0024] The present invention provides a method for replacing a mechanical switch with a semiconductor device, aiming to solve the above technical problems in the prior art.

[0025] The technical solution of the present invention and how the technical solution of the present invention solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present invention will be described below in conjunction with the accompanying drawings.

[0026] Embodiment 1: An embodiment of periodically providing a DC pulse waveform is as follows: in a high-voltage DC system, the branch where the semiconductor device is located is operated with load, and another branch is an open-circuit load branch, and the semiconductor device includes a MOS tube switch circuit; The steps to output waveform are as follows: Figure 1 As shown below: s1. Access to external digital signals; s2, the digital signal is output to the MOS tube switch circuit through the level conversion circuit and the gate drive circuit; s3, the control end of the MOS tube switch circuit connected to the gate drive circuit output is powered off; s31. When the control end is powered off, the branch where the semiconductor device is located is in a load retention path state and then disconnected with a time delay; s32, the load of the disconnected load branch begins to decrease until the load value decreases to within the conduction threshold range, and the disconnected load branch becomes conductive; When the digital signal is periodically output to the MOS tube switch circuit, the branch where the semiconductor device is located outputs a DC pulse waveform.

[0027] s4, periodically execute s1; s5. The branch where the semiconductor device is located outputs a DC pulse waveform.

[0028] Step s5 is specifically as follows: the branch where the semiconductor device with load is located is connected to external digital signal control, and the disconnected load branch generates DC pulses during the period from the time delay disconnection to the load starting to reduce until the load value is reduced to the conduction threshold range, and the corresponding process of generating DC pulses is periodically controlled by external digital signals. As a control device that converts DC into pulses, the DC power supply is converted into a pulse power supply to provide pulse power supply services for the load, and the maximum speed can reach 20MS.

[0029] Embodiment 2: A single provision as an electronic switch can achieve fast closing and shutting down under current without any arcing, and another branch is used as a subsequent power supply path. The embodiment is as follows: In embodiment 1, step s4, when the load of the branch where the semiconductor device is located is greater than the delay time of the load and greater than the load of the disconnected load branch, it starts to shrink until the load value is reduced to the conduction threshold range, and s1 is executed once, then the state becomes that the disconnected load branch does not work when the branch where the semiconductor device is located is running with load, and the disconnected load branch conducts current in the high-voltage DC system to electrically connect the subsequent circuit path when the branch where the semiconductor device is located is disconnected with load access control signal. The MOS tube switch circuit is connected to a high level and delays the disconnected load branch to be turned on. The disconnected load branch delays the on-state to provide DC power for the subsequent circuit, and the MOS tube switch circuit is connected to a high level as an electronic switch of the high-voltage DC system.

[0030] In the several embodiments provided by the present invention, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are only illustrative, for example, the division of the modules is only a logical function division, and there may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0031] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0032] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of hardware plus software functional modules.

[0033] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0034] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

[0035] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The description and examples are to be considered exemplary only, and the true scope and spirit of the present invention is indicated by the claims above.

[0036] It should be understood that the present invention is not limited to the exact construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for replacing a mechanical switch with a semiconductor device, characterized in that: include: In a high-voltage direct current system, the branch where the semiconductor device is located is operated with load, while the other branch is an open-circuit load branch, and the semiconductor device includes a MOS tube switch circuit; When an external digital signal is connected, the digital signal controls the control end of the MOS tube switch circuit to be powered off through the level conversion circuit and the gate drive circuit. When the control end is powered off, the load branch where the semiconductor device is located remains in the path state and then delays disconnection, and the load of the other branch begins to decrease until the load value is reduced to within the conduction threshold range, and the disconnected load branch becomes conductive.

2. A method for replacing a mechanical switch with a semiconductor device according to claim 1, characterized in that: In the high-voltage DC system, the original conduction signal is output through the branch where the semiconductor device with the load is located. After receiving the external digital signal, the delay time of the branch where the semiconductor device with the load is located is less than the time from the load of the other branch starting to decrease until the load value is reduced to within the conduction threshold range.

3. A method for replacing a mechanical switch with a semiconductor device according to claim 2, characterized in that: The other branch does not work when the branch where the semiconductor device is located is running with load, and the other branch conducts current in the high-voltage DC system to electrically connect the subsequent circuit path when the branch where the semiconductor device is located is connected to a control signal disconnection with load.

4. The method of replacing a mechanical switch with a semiconductor device according to claim 2, characterized in that: The branch where the loaded semiconductor device is located is connected to external digital signal control, and the disconnected load branch generates a DC pulse in the stage from the delayed disconnection to the load starting to reduce until the load value is reduced to the conduction threshold range. The corresponding process of generating DC pulses is periodically controlled by external digital signals.

5. A method for replacing a mechanical switch with a semiconductor device according to claim 4, characterized in that: The semiconductor device is disposed on a passage in a vacuum environment.

6. A method of replacing a mechanical switch with a semiconductor device according to claim 4, characterized in that: When the digital signal is periodically output to the MOS tube switch circuit, the branch where the semiconductor device is located outputs a DC pulse waveform.

7. The method of replacing a mechanical switch with a semiconductor device according to claim 4, characterized in that: When a single digital signal is output to the semiconductor device, the MOS tube switch circuit is connected to a high level and the other branch is delayed to be turned on. The other branch is delayed to be turned on to provide a DC power supply for the subsequent circuit. The MOS tube switch circuit is connected to a high level as an electronic switch of the high-voltage DC system.

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