Control circuit for synchronous switching of DC blocking devices of multiple transformers

Abstract

The invention discloses a control circuit for synchronous switching of multiple transformer DC blocking devices, which comprises N DC blocking devices (N is greater than 2), the DC blocking devices are in cascade connection, and each DC blocking device comprises a controller, a linkage switching control branch and a transformer connecting branch, a first port of the controller is connected with the input end of the linkage input control branch and sends linkage input control signals, a second port of the controller is connected with the first output end of the linkage input control branch and obtains linkage input execution signals, and a third port of the controller is connected with the second output end of the linkage input control branch. And the controller is connected with the change-over switch on the transformer connecting branch and controls the change-over switch to be closed according to a linkage input execution signal, so that synchronous input of the N blocking devices is realized. The damage caused by extra direct-current magnetic bias borne by other transformers due to asynchronous switching is avoided, and the service life is prolonged.

Description

Technical Field

[0001] The invention relates to the field of power plants and transformer substations, and in particular to a control circuit for synchronously switching on and off direct current isolation devices of multiple transformers. Background Art

[0002] In recent years, with the rapid development of power grids, the hybrid transmission mode of DC and AC transmission has become more and more common. In this process, the single-pole grounding operation of the DC transmission line causes part of the DC current to flow into the AC substation system, which has an adverse effect on the neutral point of the transformer, and then leads to the increase of DC bias magnetism, magnetic saturation and harmonics of the transformer, affecting the safe and stable operation of the transformer and the AC system. In addition, the continuous noise and vibration have also had a negative impact on the daily life of surrounding residents.

[0003] To alleviate this problem, the PAC-50K DC isolation device isolates the DC component by connecting a capacitor to the neutral point of the transformer, thereby blocking the impact of DC current on the transformer. However, when multiple transformer systems are running in parallel, each DC isolation device works independently and cannot be put into operation or out of operation synchronously, resulting in problems such as increased DC bias magnetism in the absence of synchronization. In particular, when a single device fails or is under maintenance, the load of other devices is increased, which in turn affects the safety and stability of the system. Summary of the invention

[0004] The embodiment of the present invention provides a control circuit for synchronously switching on and off of multiple transformer DC isolation devices, so as to solve the problem of increased DC bias magnetic field caused by the inability of the DC isolation devices to achieve synchronous switching on or synchronous switching off.

[0005] Based on the above purpose, in one embodiment, a control circuit for synchronously switching on and off multiple transformer DC isolation devices is provided, comprising: N DC isolation devices, wherein N>2, each of the DC isolation devices is cascade-connected, and each of the DC isolation devices comprises: a controller, a linkage switching control branch, and a transformer connection branch; The first port of the controller is connected to the input end of the linkage input control branch, and is used to send a linkage input control signal to the linkage input control branch. The second port of the controller is connected to the first output end of the linkage input control branch, and is used to obtain a linkage input execution signal. The third port of the controller is connected to the second output end of the linkage input control branch, and is used to provide a power supply signal to the linkage input control branch of other DC isolation devices through the second output end of the linkage input control branch. The controller is connected to the switching switch on the transformer connecting branch, and is used to control the switching switch on the transformer connecting branch to close according to the linkage input execution signal, so as to realize the synchronous input of the N DC isolation devices.

[0006] In one embodiment, each of the DC isolation devices further includes: a global input status monitoring branch, the input end of the global input status monitoring branch is connected to the fourth port of the controller, and is used to obtain the DC isolation input status monitoring signal output by the controller; the first output end of the global input status monitoring branch is connected to the fifth port of the controller, and is used to output the global input status monitoring signal to the controller; the second output ends of the global input status monitoring branches of each of the DC isolation devices are connected to form a DC isolation input status ring loop.

[0007] In one embodiment, the global input status monitoring branch includes: a DC isolation input status switch and a global input status switch, the control end of the DC isolation input status switch serves as the input end of the global input status monitoring branch, the two ends of the DC isolation input status switch serve as the second output end of the global input status monitoring branch, the input end of the global input status switch is connected to the output end of the DC isolation input status switch, and the output end of the global input status switch serves as the first output end of the global input status monitoring branch.

[0008] In one embodiment, it also includes: a control host, which is respectively connected to the sixth port of the controller of each of the DC isolation devices, and is used to obtain a global startup status monitoring signal sent by each of the controllers, and determine whether the N DC isolation devices are synchronously started according to the N global startup status monitoring signals.

[0009] In one embodiment, the DC isolation device further comprises: a camera module, the input end of which is used to obtain a first switch image containing a switch on the transformer connection branch and a second switch image containing a DC isolation state switch of a global state monitoring branch; The output end of the camera module is connected to the seventh port of the controller, and is used to input the first switch image and the second switch image into the trained switch state monitoring model, output the input state of the switching switch and the input state of the DC isolation input state switch to the controller, and send the input state of the switching switch and the input state of the DC isolation input state switch to the control host through the sixth port of the controller; The control host is used to determine whether each of the DC isolation devices is put into operation synchronously according to the operation status of the N switching switches, and to determine whether the controller has a communication failure according to the operation status of the N DC isolation operation status switches.

[0010] In one embodiment, a control circuit for synchronously switching on and off multiple transformer DC isolation devices is provided, comprising: N DC isolation devices, wherein N>2, each of the DC isolation devices is cascade-connected, and each of the DC isolation devices comprises: a controller, a linkage exit control branch, and a transformer connection branch; The eighth port of the controller is connected to the input end of the linkage exit control branch, and is used to send a linkage exit control signal to the linkage exit control branch. The ninth port of the controller is connected to the first output end of the linkage exit control branch, and is used to obtain a linkage exit execution signal. The second output ends of the linkage exit control branches of the DC isolation devices are connected to each other to form a DC isolation exit ring loop. The controller is connected to the switching switch on the transformer connecting branch, and is used to control the switching switch on the transformer connecting branch to be disconnected according to the linkage exit execution signal, so as to realize the synchronous exit of the N DC isolation devices.

[0011] In one embodiment, each of the DC isolation devices further includes: a global exit status monitoring branch, wherein the input end of the global exit status monitoring branch is connected to the tenth port of the controller, for obtaining the DC isolation exit status monitoring signal output by the controller, the first output end of the global exit status monitoring branch is connected to the eleventh port of the controller, for outputting the global exit status monitoring signal to the controller, and the twelfth port of the controller is connected to the second output end of the global exit status monitoring branch, for obtaining the global exit status monitoring signal of other DC isolation devices through the second output end of the global exit status monitoring branch.

[0012] In one embodiment, the global exit status monitoring branch includes: a DC isolation exit status switch and a global exit status switch, the control end of the DC isolation exit status switch serves as the input end of the global exit status monitoring branch, one end of the DC isolation exit status switch is connected to the power supply of the DC isolation device, the other end of the DC isolation exit status switch serves as the second output end of the global exit status monitoring branch, the other end of the DC isolation exit status switch is also connected to the input end of the global exit status switch, and the output end of the global exit status switch serves as the first output end of the global exit status monitoring branch.

[0013] In one embodiment, it also includes: a control host, which is respectively connected to the sixth port of the controller of each of the DC isolation devices, and is used to obtain a global exit status monitoring signal sent by each of the controllers, and determine whether the N DC isolation devices exit synchronously according to the N global exit status monitoring signals.

[0014] In one embodiment, the DC isolation device further comprises: a camera module, the input end of which is used to obtain a first switch image containing a switch on the transformer connection branch and a second switch image containing a DC isolation exit state switch of a global exit state monitoring branch; The output end of the camera module is connected to the seventh port of the controller, and is used to input the first switch image and the second switch image into the trained switch state monitoring model, output the exit state of the switching switch and the exit state of the DC isolation exit state switch to the controller, and send the exit state of the switching switch and the exit state of the DC isolation exit state switch to the control host through the sixth port of the controller; The control host is used to determine whether each of the DC isolation devices exits synchronously according to the exit status of the N switching switches, and determine whether the controller has a communication failure according to the exit status of the N DC isolation exit status switches.

[0015] The above-mentioned control circuit for synchronously switching on and off of multiple transformer DC isolation devices connects the DC isolation devices in cascade so that the controllers of the DC isolation devices can communicate with each other, and controls the DC isolation devices through a linkage switching control branch to achieve synchronous switching operation, thereby suppressing the influence of DC current on the transformer, avoiding transformer failure due to DC bias magnetization, and ensuring safe and stable operation of the transformer. The linkage switching off control branch controls the DC isolation devices to achieve synchronous switching off action, thereby avoiding other transformers from bearing additional DC bias magnetization current due to asynchronous switching off, thereby avoiding damage to the transformer and extending the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0017] Figure 1 is a circuit diagram of linkage input control in one embodiment of the present invention; Figure 2 It is a schematic diagram of signals of all 1SK switches when any DC isolation device meets the input conditions in one embodiment of the present invention; Figure 3 is a schematic diagram of signals of all 1SK switches when one DC isolation device is in an abnormal state in one embodiment of the present invention; Figure 4 It is a schematic diagram of voltage changes across the capacitor of a DC isolation device when one DC isolation device enters a bypass protection state when the DC isolation device is in an abnormal state in one embodiment of the present invention; Figure 5 It is a circuit diagram of linkage input control and linkage input monitoring in one embodiment of the present invention; Figure 6 is a circuit diagram of a linkage exit control in one embodiment of the present invention; Figure 7 It is a schematic diagram of signals of all 1SK switches when all DC isolation devices meet the exit conditions in one embodiment of the present invention; Figure 8 It is a signal diagram of all 1SK switches when one DC isolation device does not meet the exit condition or is in an abnormal state in one embodiment of the present invention; Fig. 9 It is a circuit diagram of linkage exit control and linkage exit monitoring in one embodiment of the present invention.

[0018] Figure numerals: 1. controller, 101. first port of controller, 102. second port of controller, 103. third port of controller, 104. fourth port of controller, 105. fifth port of controller, 106. sixth port of controller, 108. eighth port of controller, 109. ninth port of controller, 110. tenth port of controller, 111. eleventh port of controller, 112. twelfth port of controller, 3. interlocking input control branch, 5. control host, 7. global input status monitoring branch, 9. interlocking exit control branch, 11. global exit status monitoring branch. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] It should be understood that the present invention can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, providing these embodiments will make the disclosure thorough and complete and fully convey the scope of the present invention to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals throughout represent the same elements.

[0021] It should be understood that when an element or layer is referred to as being "on, adjacent to, connected to or coupled to other elements or layers, it may be directly on, adjacent to, connected to or coupled to other elements or layers, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on, directly adjacent to, directly connected to or directly coupled to other elements or layers, there may be no intervening elements or layers. It should be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer or part discussed below may be represented as a second element, component, region, layer or part.

[0022] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein for ease of description to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that the spatially relative terms are intended to include different orientations of the device in use and operation in addition to the orientations shown in the figures. For example, if the device in the accompanying drawings is flipped, then the elements or features described as "under other elements" or "under" or "under" will be oriented as "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0023] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0024] In order to fully understand the present invention, detailed structures and steps will be presented in the following description to illustrate the technical solutions proposed by the present invention. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0025] In one embodiment, a control circuit for synchronously switching on and off multiple transformer DC isolation devices is provided, such as Figure 1 As shown, it includes: N DC isolation devices, wherein N>2, each of the DC isolation devices is cascade-connected, and each of the DC isolation devices includes: a controller 1, a linkage input control branch 3, and a transformer connection branch; The first port 101 of the controller is connected to the input end of the linkage input control branch 3, and is used to send a linkage input control signal to the linkage input control branch 3. The second port 102 of the controller is connected to the first output end of the linkage input control branch 3, and is used to obtain a linkage input execution signal. The third port 103 of the controller is connected to the second output end of the linkage input control branch 3, and is used to provide a power supply signal to the linkage input control branch of other DC isolation devices through the second output end of the linkage input control branch 3. The controller 1 is connected to the switch on the transformer connecting branch, and is used to control the switching switch on the transformer connecting branch to close according to the linkage input execution signal, so as to realize the synchronous input of the N DC isolation devices.

[0026] Among them, Figure 1 As shown, the linkage input control branch 3 is specifically provided with a linkage input control output switch, a linkage input execution input switch and a power supply. One end of the linkage input control output switch is connected to the power supply, and the other end is connected to the linkage input execution switch. Among them, the linkage input control output switch is a relay switch, and the linkage input execution switch is an optocoupler.

[0027] The working process of the above control circuit is: When the controller 1 of any one of the N DC isolation devices detects that the DC current at the neutral point of the transformer connected thereto is greater than or equal to 50A, that is, when the input condition is met, the first port 101 of the controller sends a linkage input control signal to the linkage input control branch 3, so that the linkage input control output switch of the linkage input control branch 3 is closed, and the power supply signal is output to the linkage input execution input switch to close it, and the second port 102 of the controller obtains the linkage input execution signal output by the first output end of the linkage input control branch 3, and closes the switch on the transformer connection branch, so that the DC isolation device enters the input state; Output the power signal to the linkage input execution switch to close it. Figure 2As shown, at this time, let N=3, switch 1SK is the linkage input execution switch, and the second output end of the linkage input control branch 3 also outputs a power signal to the linkage input control branches of other DC isolation devices, so that the linkage input execution switches of other DC isolation devices are closed, that is, the switch 1SK signal is 1, and the switches on the transformer connection branches of other DC isolation devices are also closed, so that other DC isolation devices also enter the input state synchronously, thereby realizing the synchronous input of N DC isolation devices.

[0028] like Figure 3 As shown, let N=3 at this time, switch 1SK is the linkage input execution switch. When one DC isolation device is in an abnormal state, such as the DC bias magnetic abnormality is serious and exceeds the load of the DC isolation device, even if the other two DC isolation devices meet the input conditions, the linkage input execution switch of the abnormal DC isolation device remains disconnected, and all DC isolation devices do not enter the input state; like Figure 4 As shown, at this time the system enters the bypass protection state, quickly releases the voltage across the DC isolation capacitor, restores the DC isolation device to normal state, and starts to be used again.

[0029] In this embodiment, the DC isolation devices are cascaded to allow the controllers of the DC isolation devices to communicate with each other, and the DC isolation devices are controlled by the linkage control branch to achieve synchronous operation, thereby suppressing the influence of DC current on the transformer, avoiding transformer failure due to DC bias magnetization, and ensuring safe and stable operation of the transformer.

[0030] In one embodiment, if Figure 5 As shown, each of the DC isolation devices also includes: a global input status monitoring branch 7, the input end of the global input status monitoring branch 7 is connected to the fourth port 104 of the controller, and is used to obtain the DC isolation input status monitoring signal output by the controller 1, the first output end of the global input status monitoring branch 7 is connected to the fifth port 105 of the controller, and is used to output the global input status monitoring signal to the controller 1, and the second output ends of the global input status monitoring branches 7 of each of the DC isolation devices are connected to form a DC isolation input status ring loop.

[0031] Among them, the working process of the above control circuit is: When the controller 1 of any one of the N DC isolation devices detects that the DC current at the neutral point of the transformer connected thereto is greater than or equal to 50A, that is, when the input condition is met, the first port 101 of the controller sends a linkage input control signal to the linkage input control branch 3, so that the linkage input control output switch of the linkage input control branch 3 is closed, and the power supply signal is output to the linkage input execution input switch to close it, and the second port 102 of the controller obtains the linkage input execution signal output by the first output end of the linkage input control branch 3, and closes the switch on the transformer connection branch, so that the DC isolation device enters the input state; While outputting the power signal to the linkage input execution input switch to close it, the second output end of the linkage input control branch 3 also outputs the power signal to the linkage input control branches of other DC isolation devices, so that the linkage input execution input switches of other DC isolation devices are closed, and the switches on the transformer connection branches of other DC isolation devices are also closed, so that other DC isolation devices also enter the input state synchronously; When the controller 1 of the DC isolation device detects that the DC isolation device enters the start-up state, the fourth port 104 of the controller outputs the DC isolation start-up state monitoring signal to the input end of the global start-up state monitoring branch 7, and the second output ends of each global start-up state monitoring branch 7 are connected to form a DC isolation start-up state ring loop, and then the global start-up state monitoring signal is output to the fifth port 105 of the controller through the first output end of the global start-up state monitoring branch 7, so as to realize the synchronous start-up of N DC isolation devices.

[0032] In this embodiment, a global startup status monitoring branch is set to transmit the global startup status monitoring signal of each DC isolation device to the controller of each DC isolation device, and the operating status of each DC isolation device is monitored in real time, thereby realizing unified monitoring and management of the DC isolation startup status of the entire system, so that the controllers of each DC isolation device can communicate with each other, and each DC isolation device can be controlled by a linkage startup control branch to realize synchronous startup and operation, thereby suppressing the influence of DC current on the transformer, avoiding transformer failure due to DC bias magnetization, and ensuring safe and stable operation of the transformer.

[0033] In one embodiment, if Figure 5 As shown, the global input status monitoring branch 7 includes: a DC isolation input status switch and a global input status switch, the control end of the DC isolation input status switch serves as the input end of the global input status monitoring branch 7, the two ends of the DC isolation input status switch serve as the second output end of the global input status monitoring branch 7, the input end of the global input status switch is connected to the output end of the DC isolation input status switch, and the output end of the global input status switch serves as the first output end of the global input status monitoring branch 7.

[0034] Among them, Figure 5 As shown, the control end of the DC isolation state switch is connected to the fourth port 104 of the controller, and is used as the input end of the global input state monitoring branch 7 to receive the DC isolation state monitoring signal output by the controller 1. The two ends of the DC isolation state switch serve as the second output ends of the global input state monitoring branch 7, and are connected to the DC isolation state switches of the global input state monitoring branches of other DC isolation devices to form a DC isolation state loop. The output end of the DC isolation state switch is also connected to the input end of the global input state switch, and is used to receive the global input state monitoring signal of the DC isolation state loop and output it to the fifth port 105 of the controller, wherein the DC isolation state switch is a relay switch, and the global input state switch is an optical coupler.

[0035] The working process of the above control circuit is: When the controller 1 of any one of the N DC isolation devices detects that the DC current at the neutral point of the transformer connected thereto is greater than or equal to 50A, that is, when the input condition is met, the first port 101 of the controller sends a linkage input control signal to the linkage input control branch 3, so that the linkage input control output switch of the linkage input control branch 3 is closed, and the power supply signal is output to the linkage input execution input switch to close it, and the second port 102 of the controller obtains the linkage input execution signal output by the first output end of the linkage input control branch 3, and closes the switch on the transformer connection branch, so that the DC isolation device enters the input state; While outputting the power signal to the linkage input execution input switch to close it, the second output end of the linkage input control branch 3 also outputs the power signal to the linkage input control branches of other DC isolation devices, so that the linkage input execution input switches of other DC isolation devices are closed, and the switches on the transformer connection branches of other DC isolation devices are also closed, so that other DC isolation devices also enter the input state synchronously; When the controller 1 of the DC isolation device detects that the DC isolation device enters the input state, the fourth port 104 of the controller outputs the DC isolation input state monitoring signal to the DC isolation input state switch of the global input state monitoring branch 7, and closes the DC isolation input state switch. When the DC isolation input state switches in all the DC isolation devices are all closed, a DC isolation input state ring loop is formed, and the DC isolation input state monitoring signal is transmitted to the global state switches of each global input state monitoring branch 7 through the DC isolation input state ring loop and closes them. At this time, the global input state monitoring signal is 1, and then the global input state monitoring signal is transmitted to the controller 1 through the fifth port 105 of the controller, so as to realize the synchronous input of N DC isolation devices; When one of the N DC isolation devices fails and cannot enter the start-up state synchronously with other DC isolation devices, its DC isolation start-up state switch is in the disconnected state. At this time, the DC isolation start-up state ring loop cannot form a path, and the DC isolation start-up state monitoring signal cannot be transmitted through the DC isolation start-up state ring loop. The global state switch of the global start-up state monitoring branch 7 is also disconnected. At this time, the global start-up state monitoring signal is 0, and the global start-up state monitoring signal is transmitted to the controller 1 through the fifth port 105 of the controller.

[0036] In this embodiment, a DC isolation state switch is provided in the global state monitoring branch, and the DC isolation state switches in each DC isolation device are connected in series to form a DC isolation state ring loop, thereby ensuring that only when all DC isolation devices enter the state synchronously, the global state switch of the global state monitoring branch can receive the signal and transmit it to the controller of each DC isolation device, thereby achieving the unification of the DC isolation state of the entire system, ensuring that each DC isolation device is put into operation synchronously, suppressing the influence of DC current on the transformer, avoiding transformer failure due to DC bias magnetization, and ensuring the safe and stable operation of the transformer.

[0037] In one embodiment, if Figure 5 The device further comprises: a control host 5, wherein the control host 5 is respectively connected to the sixth port 106 of the controller of each of the DC isolation devices, and is used to obtain a global startup status monitoring signal sent by each of the controllers, and determine whether the N DC isolation devices are synchronously started according to the N global startup status monitoring signals.

[0038] Among them, the working process of the above control circuit is: When the controller of any one of the N DC isolation devices detects that the DC current at the neutral point of the transformer connected thereto is greater than or equal to 50A, that is, when the input condition is met, the first port 101 of the controller sends a linkage input control signal to the linkage input control branch 3, so that the linkage input control output switch of the linkage input control branch 3 is closed, and the power supply signal is output to the linkage input execution input switch to close it, and the second port 102 of the controller obtains the linkage input execution signal output by the first output end of the linkage input control branch 3, and closes the switch on the transformer connection branch, so that the DC isolation device enters the input state; While outputting the power signal to the linkage input execution input switch to close it, the second output end of the linkage input control branch 3 also outputs the power signal to the linkage input control branches of other DC isolation devices, so that the linkage input execution input switches of other DC isolation devices are closed, and the switches on the transformer connection branches of other DC isolation devices are also closed, so that other DC isolation devices also enter the input state synchronously; When the controller 1 of the DC isolation device detects that the DC isolation device enters the startup state, the fourth port 104 of the controller outputs a DC isolation startup state monitoring signal to the DC isolation startup state switch of the global startup state monitoring branch 7, and closes the DC isolation startup state switch. When the DC isolation startup state switches in all the DC isolation devices are all closed, a DC isolation startup state ring loop is formed, and the DC isolation startup state monitoring signal is transmitted to the global state switches of each global startup state monitoring branch through the DC isolation startup state ring loop and closes them. Finally, the global startup state monitoring signal is transmitted to the controller 1 through the fifth port 105 of the controller. The controller 1 outputs the received global startup state monitoring signal to the control host 5 through the sixth port 106 of the controller. The control host 5 determines whether the N DC isolation devices are synchronously started according to the received N global startup state monitoring signals. If the received global startup state monitoring signal is 1, the synchronous startup of the N DC isolation devices is achieved. When one of the N DC isolation devices fails and cannot enter the startup state synchronously with other DC isolation devices, its DC isolation startup state switch is in the disconnected state. At this time, the DC isolation startup state loop cannot form a path, and the DC isolation startup state monitoring signal cannot be transmitted through the DC isolation startup state loop. The global state switch of the global startup state monitoring branch 7 is also disconnected. At this time, the global startup state monitoring signal is 0. The global startup state monitoring signal is transmitted to the controller 1 through the fifth port 105 of the controller. The controller 1 outputs the received global startup state monitoring signal to the control host 5 through the sixth port 106 of the controller. At the same time, the controller 1 also outputs the alarm signal to the control host 5. Since synchronous startup is not achieved, the control host 5 sends a signal to each controller to make the DC isolation device that has entered the startup state exit the startup. The control host 5 determines the location of the faulty DC isolation device according to the received alarm signal, and exits the faulty DC isolation device from the system for maintenance. After the faulty device exits the system, it will not affect the normal operation of other DC isolation devices in the system.

[0039] In this embodiment, the control host is connected to the sixth port of the controller of each DC isolation device to obtain a global startup status monitoring signal, and whether N DC isolation devices are synchronously started is determined based on the global startup status monitoring signal, so as to centrally manage and monitor the working status of each DC isolation device, promptly discover and repair it when a fault occurs, ensure that each DC isolation device is put into operation synchronously, suppress the influence of DC current on the transformer, avoid transformer failure due to DC bias magnetism, reduce equipment damage, and increase the service life of the equipment.

[0040] In one embodiment, the DC isolation device further comprises: a camera module, the input end of which is used to obtain a first switch image containing a switch on the transformer connection branch and a second switch image containing a DC isolation state switch of a global state monitoring branch; The output end of the camera module is connected to the seventh port of the controller, and is used to input the first switch image and the second switch image into the trained switch state monitoring model, output the input state of the switching switch and the input state of the DC isolation input state switch to the controller 1, and send the input state of the switching switch and the input state of the DC isolation input state switch to the control host 5 through the sixth port 106 of the controller; The control host 5 is used to determine whether the DC isolation devices are synchronously switched on according to the switched-on states of the N switching switches, and to determine whether the controller 1 has a communication failure according to the switched-on states of the N DC isolation switching state switches.

[0041] Among them, the camera module is used to obtain the first switch image and the second switch image, and output the first switch image and the second switch image taken in real time to the switch state monitoring model. The switch state monitoring model adopts a neural network with an encoder and a decoder structure. The trained switch state monitoring model can be used to predict the input state of the switching switch and the input state of the DC isolation input state switch. The training process of the switch state monitoring model is: input the first switch image sample and the second switch image sample with the input state label to the switch state monitoring model under the initial parameters, and use the cross loss entropy function to calculate the deviation between the prediction result of the switch state monitoring model and the input state label. When the deviation reaches the preset condition, stop the model training, update the model parameters, and obtain the trained switch state monitoring model. The switch state monitoring model can realize the switch input state prediction through a separate processor, or it can be realized through the controller 1.

[0042] The switch status monitoring model obtains the switching state of the switching switch and the DC isolation state switch according to the first switch image and the second switch image and outputs them to the controller 1, and then outputs them to the control host 5 through the controller 1 to determine whether a communication failure occurs.

[0043] The working process of the above control circuit is: When the controller of any one of the N DC isolation devices detects that the DC current at the neutral point of the transformer connected thereto is greater than or equal to 50A, that is, when the input condition is met, the first port 101 of the controller sends a linkage input control signal to the linkage input control branch 3, so that the linkage input control output switch of the linkage input control branch 3 is closed, and the power supply signal is output to the linkage input execution input switch to close it, and the second port 102 of the controller obtains the linkage input execution signal output by the first output end of the linkage input control branch 3, and closes the switch on the transformer connection branch, so that the DC isolation device enters the input state; While outputting the power signal to the linkage input execution input switch to close it, the second output end of the linkage input control branch 3 also outputs the power signal to the linkage input control branches of other DC isolation devices, so that the linkage input execution input switches of other DC isolation devices are closed, and the switches on the transformer connection branches of other DC isolation devices are also closed, so that other DC isolation devices also enter the input state synchronously; When the controller 1 of the DC isolation device detects that the DC isolation device enters the startup state, the fourth port 104 of the controller outputs the DC isolation startup state monitoring signal to the DC isolation startup state switch of the global startup state monitoring branch 7, and closes the DC isolation startup state switch. When the DC isolation startup state switches in all the DC isolation devices are all closed, a DC isolation startup state ring loop is formed, and the DC isolation startup state monitoring signal is transmitted to the global state switches of each global startup state monitoring branch 7 through the DC isolation startup state ring loop and closes them. Finally, the global startup state monitoring signal is transmitted to the controller 1 through the fifth port 105 of the controller. The controller 1 outputs the received global startup state monitoring signal to the control host 5 through the sixth port 106 of the controller. The control host 5 determines whether the N DC isolation devices are synchronously started according to the received N global startup state monitoring signals. If the received global startup state monitoring signal is 1, the synchronous startup of the N DC isolation devices is realized. If a communication failure occurs when the fourth port 104 of the controller outputs the DC isolation state monitoring signal to the DC isolation state switch of the global state monitoring branch 7, the DC isolation state ring loop cannot form a path, and the global state monitoring signal is 0, but the control host 5 does not receive the alarm signal, then the camera module obtains the first switch image of the switching switch on the transformer connection branch and the second switch image of the DC isolation state switch of the global state monitoring branch 7, and outputs them to the controller 1 through the seventh port of the controller. The controller 1 outputs the state of the switching switch and the state of the DC isolation state switch to the control host 5 through the trained switch state monitoring model. The control host 5 makes a judgment. If the state of the switching switch is closed, but the state of the DC isolation state switch is open, the control host 5 determines that a communication failure occurs, but synchronous input is achieved. At this time, only the faulty DC isolation device is exited from the system and repaired, and other DC isolation devices that have been put into operation remain in the state of operation.

[0044] In this embodiment, a camera module is provided to obtain the first switch image and the second switch image and output them to the controller, thereby obtaining the on-state of the switching switch and the on-state of the DC isolation switch, and then outputting the on-state of the switching switch and the on-state of the DC isolation switch to the monitoring host for judgment, thereby avoiding erroneous judgments due to communication failures, making the control circuit more perfect, ensuring that each DC isolation device is put into operation synchronously, suppressing the influence of DC current on the transformer, and avoiding transformer failure due to DC bias magnetism.

[0045] In one embodiment, if Figure 6 As shown, a control circuit for synchronously switching on and off multiple transformer DC isolation devices is provided, comprising: N DC isolation devices, wherein N>2, each of the DC isolation devices is cascade-connected, and each of the DC isolation devices comprises: a controller 1, a linkage exit control branch 9, and a transformer connection branch; The eighth port 108 of the controller is connected to the input end of the linkage exit control branch 9, and is used to send a linkage exit control signal to the linkage exit control branch 9. The ninth port 109 of the controller is connected to the first output end of the linkage exit control branch 9, and is used to obtain a linkage exit execution signal. The second output ends of the linkage exit control branches of the DC isolation devices are connected to each other to form a DC isolation exit ring loop. The switching switch on the transformer connecting branch is also used to control the switching switch on the transformer connecting branch to be disconnected according to the linkage exit execution signal, so as to realize the synchronous exit of the N DC isolation devices.

[0046] Among them, Figure 6 As shown, the linkage exit control branch 9 is specifically provided with a linkage exit control output switch and a linkage exit input switch, the controlled end of the linkage exit control output switch is connected to the eighth port 108 of the controller, and both ends are connected to the second output end of the linkage exit control branch 9 of other DC isolation devices to form a DC isolation exit ring loop, one end of the linkage exit control output switch is also connected to the input end of the linkage exit input switch, and the output end of the linkage exit input switch is connected to the ninth port 109 of the controller, wherein the linkage input control output switch is a relay switch, and the linkage input execution input switch is an optical coupler.

[0047] The working process of the above control circuit is: When the controller 1 of the DC isolation device detects that the DC current at the neutral point of the transformer connected to it is less than 50A, that is, the exit condition is met, the eighth port 108 of the controller sends a linkage exit control signal to the linkage exit control branch 9 to close the linkage exit control output switch. When all the DC isolation devices meet the exit condition, the linkage exit control branches 9 of all the DC isolation devices form a DC isolation exit ring loop, and transmit the linkage exit control signal to the input end of the linkage exit input switch of the linkage exit control branch 9 of each DC isolation device through the DC isolation exit ring loop. The linkage exit input switch is closed after receiving the linkage exit control signal. Figure 7 As shown, at this time, let N=3, switch 1SK is a linkage exit switch, that is, the signal of switch 1SK is 1, and the linkage exit execution signal is sent to controller 1 through the ninth port 109 of the controller, and the ninth port 109 of the controller obtains the linkage exit execution signal output by the linkage exit control branch 9, and disconnects the switch on the transformer connection branch, so that the DC isolation device enters the exit state, and realizes the synchronous exit of N DC isolation devices; like Figure 8 As shown, let N=3 at this time, switch 1SK is the linkage exit switch. When one DC isolation device does not meet the exit conditions or is in an abnormal state, such as a serious DC bias magnetic abnormality, the linkage exit switches of all DC isolation devices remain disconnected, and all DC isolation devices remain in the on state and do not exit.

[0048] In this embodiment, each DC isolation device is controlled by a linkage exit control branch to achieve synchronous exit operation, thereby suppressing the influence of DC current on the transformer, preventing the transformer that has not exited from malfunctioning due to excessive DC bias magnetism, and preventing the transformer winding from being damaged by a large through current, thereby ensuring the safe and stable operation of the transformer.

[0049] In one embodiment, if Fig. 9 As shown, each of the DC isolation devices also includes: a global exit status monitoring branch 11, the input end of the global exit status monitoring branch 11 is connected to the tenth port 110 of the controller, and is used to obtain the DC isolation exit status monitoring signal output by the controller 1, the first output end of the global exit status monitoring branch 11 is connected to the eleventh port 111 of the controller, and is used to output the global exit status monitoring signal to the controller 1, and the twelfth port 112 of the controller is connected to the second output end of the global exit status monitoring branch 11, and is used to obtain the global exit status monitoring signal of other DC isolation devices through the second output end of the global exit status monitoring branch 11.

[0050] Among them, the working process of the above control circuit is: When the controller 1 of the DC isolation device detects that the DC current at the neutral point of the transformer connected thereto is less than 50A, that is, when the exit condition is met, the eighth port 108 of the controller sends a linkage exit control signal to the linkage exit control branch 9, so that the linkage exit control output switch is closed. When all the DC isolation devices meet the exit condition, the linkage exit control branches 9 of all the DC isolation devices form a DC isolation exit ring loop, and transmit the linkage exit control signal to the input end of the linkage exit input switch of the linkage exit control branch 9 of each DC isolation device through the DC isolation exit ring loop. The linkage exit input switch is closed after receiving the linkage exit control signal, and the linkage exit execution signal is sent to the controller 1 through the ninth port 109 of the controller. The ninth port 109 of the controller obtains the linkage exit execution signal output by the linkage exit control branch 9, and disconnects the switch on the transformer connection branch, so that the DC isolation device enters the exit state. When the controllers 1 of all DC isolation devices detect that the DC isolation devices have entered the exit state, the tenth port 110 of the controller outputs the DC isolation exit state monitoring signal to the input end of the global exit state monitoring branch 11, so that the power signal is disconnected. When the signal power of all DC isolation devices is disconnected, the global exit state monitoring branch 11 obtains the global exit state monitoring signal of other DC isolation devices through its second output end. When the global exit state monitoring signals of all DC isolation devices are 0, the first output end of the global exit state monitoring branch 11 outputs the global exit state monitoring signal to the controller 1 through the eleventh port 111 of the controller, so as to realize the synchronous exit of N DC isolation devices.

[0051] In this embodiment, a global exit status monitoring branch is set to transmit the global exit status monitoring signal of each DC isolation device to the controller, thereby realizing unified monitoring and management of the DC isolation exit status of the entire system, so that the controllers of each DC isolation device can communicate with each other, and each DC isolation device can be controlled by a linkage exit control branch to realize synchronous operation, thereby suppressing the influence of DC current on the transformer, avoiding transformer failure due to DC bias magnetization, and ensuring safe and stable operation of the transformer.

[0052] In one embodiment, if Fig. 9 As shown, the global exit status monitoring branch 11 includes: a DC isolation exit status switch and a global exit status switch, the control end of the DC isolation exit status switch serves as the input end of the global exit status monitoring branch 11, one end of the DC isolation exit status switch is connected to the power supply of the DC isolation device, the other end of the DC isolation exit status switch serves as the second output end of the global exit status monitoring branch 11, the other end of the DC isolation exit status switch is also connected to the input end of the global exit status switch, and the output end of the global exit status switch serves as the first output end of the global exit status monitoring branch 11.

[0053] Among them, Fig. 9 As shown, the control end of the DC isolation exit state switch is connected to the tenth port 110 of the controller, serving as the input end of the global exit state monitoring branch 11, one end of which is connected to the power supply, and the other end is connected to the input end of the global exit state switch, and is connected to the second output end of other global exit state monitoring branches through the twelfth port 112 of the controller, serving as the second output end of the global exit state monitoring branch 11, and the output end of the global exit state switch serves as the first output end of the global exit state monitoring branch 11, connected to the eleventh port 111 of the controller, wherein the DC isolation exit state switch is a relay switch, and the global exit state switch is an optocoupler.

[0054] The working process of the above control circuit is: When the controller of the DC isolation device detects that the DC current at the neutral point of the transformer connected to it is less than 50A, that is, the exit condition is met, the eighth port 108 of the controller sends a linkage exit control signal to the linkage exit control branch 9, so that the linkage exit control output switch is closed. When all the DC isolation devices meet the exit condition, the linkage exit control branches 9 of all the DC isolation devices form a DC isolation exit ring loop, and the linkage exit control signal is transmitted to the input end of the linkage exit input switch of the linkage exit control branch 9 of each DC isolation device through the DC isolation exit ring loop. The linkage exit input switch is closed after receiving the linkage exit control signal, and the linkage exit execution signal is sent to the controller 1 through the ninth port 109 of the controller. The ninth port 109 of the controller obtains the linkage exit execution signal output by the linkage exit control branch 9, and disconnects the switch on the transformer connection branch, so that the DC isolation device enters the exit state; When the controllers 1 of all the DC isolation devices detect that the DC isolation devices have entered the exit state, the tenth port 110 of the controller outputs the DC isolation exit state monitoring signal to the input end of the global exit state monitoring branch 11, and the DC isolation exit state switch is closed to disconnect the power signal. When all the DC isolation exit state switches are closed and all the power signals are disconnected, the DC isolation exit state monitoring signal (0 at this time) is transmitted to the global exit state switch of each DC isolation device, and the global exit state switch is closed, and the global exit state monitoring signal is transmitted to the controller 1 through the eleventh port 111 of the controller, so as to realize the synchronous exit of N DC isolation devices; When one of the N DC isolation devices fails and cannot exit synchronously with other DC isolation devices, its DC isolation exit status switch remains closed, and the global exit status switch still receives the power signal. At this time, the global exit status switch is not closed, and the global exit status monitoring signal transmitted to controller 1 is 1.

[0055] In this embodiment, by setting a DC isolation exit status switch and a global exit status switch in the global exit status monitoring branch, it is ensured that only when all DC isolation devices have achieved exit, the global exit status switch of the global exit status monitoring branch will send a global exit status monitoring signal of 0 to the controller, indicating that all DC isolation devices have achieved synchronous exit, ensuring that each DC isolation device achieves synchronous exit, suppressing the influence of DC current on the transformer, avoiding transformer failure due to DC bias magnetization, and ensuring safe and stable operation of the transformer.

[0056] In one embodiment, it also includes: a control host 5, such as Fig. 9 As shown, the control host 5 is respectively connected to the sixth port 106 of the controller of each of the DC isolation devices, and is used to obtain the global exit status monitoring signal sent by each of the controllers 1, and determine whether the N DC isolation devices exit synchronously according to the N global exit status monitoring signals.

[0057] Among them, the working process of the above control circuit is: When the controller 1 of the DC isolation device detects that the DC current at the neutral point of the transformer connected thereto is less than 50A, that is, when the exit condition is met, the eighth port 108 of the controller sends a linkage exit control signal to the linkage exit control branch 9, so that the linkage exit control output switch is closed. When all the DC isolation devices meet the exit condition, the linkage exit control branches 9 of all the DC isolation devices form a DC isolation exit ring loop, and transmit the linkage exit control signal to the input end of the linkage exit input switch of the linkage exit control branch 9 of each DC isolation device through the DC isolation exit ring loop. The linkage exit input switch is closed after receiving the linkage exit control signal, and the linkage exit execution signal is sent to the controller 1 through the ninth port 109 of the controller. The ninth port 109 of the controller obtains the linkage exit execution signal output by the linkage exit control branch 9, and disconnects the switch on the transformer connection branch, so that the DC isolation device enters the exit state. When the controllers 1 of all the DC isolation devices detect that the DC isolation devices have entered the exit state, the tenth port 110 of the controller outputs the DC isolation exit state monitoring signal to the input end of the global exit state monitoring branch 11, and the DC isolation exit state switch is closed to disconnect the power signal. When all the DC isolation exit state switches are closed and all the power signals are disconnected, the DC isolation exit state monitoring signal (which is 0 at this time) is transmitted to the global exit state switch of each DC isolation device, and the global exit state switch is closed, and the global exit state monitoring signal is transmitted to the controller 1 through the eleventh port 111 of the controller. The controller 1 transmits the received DC isolation exit state monitoring signal to the control host 5, and the control host 5 determines that if the DC isolation exit state monitoring signal is 0, it is determined that the synchronous exit of the N DC isolation devices has been achieved; When one of the N DC isolation devices fails and cannot exit synchronously with other DC isolation devices, its DC isolation exit status switch remains closed, and the global exit status switch still receives the power signal. At this time, the global exit status switch is not closed, and the global exit status monitoring signal transmitted to the controller 1 is 1. The controller 1 transmits the received DC isolation exit status monitoring signal to the control host 5, and also transmits the alarm signal to the control host 5 through the controller 1. If the DC isolation exit status monitoring signal received by the control host 5 is 1, it is determined that the synchronous exit of the N DC isolation devices has not been achieved. At this time, the DC isolation device that has successfully exited remains in the exit state, and the location of the faulty DC isolation device is determined according to the alarm signal, and the faulty DC isolation device is exited from the system for maintenance. After the faulty device exits the system, it will not affect the normal operation of other DC isolation devices in the system.

[0058] In this embodiment, the control host is connected to the sixth port of the controller of each DC isolation device to obtain a global exit status monitoring signal, and whether the N DC isolation devices are exited synchronously is determined based on the global exit status monitoring signal. The working status of each DC isolation device is centrally managed and monitored, and when a fault occurs, it is discovered and repaired in time to ensure that each DC isolation device is exited synchronously, suppress the influence of DC current on the transformer, avoid transformer failure due to DC bias magnetism, and reduce damage to the transformer equipment.

[0059] In one embodiment, the DC isolation device further comprises: a camera module, the input end of which is used to obtain a first switch image containing the switch on the transformer connection branch and a second switch image containing the DC isolation exit state switch of the global exit state monitoring branch 11; The output end of the camera module is connected to the seventh port of the controller, and is used to input the first switch image and the second switch image into the trained switch state monitoring model, output the exit state of the switching switch and the exit state of the DC isolation exit state switch to the controller 1, and send the exit state of the switching switch and the exit state of the DC isolation exit state switch to the control host 5 through the sixth port 106 of the controller; The control host 5 is used to determine whether each of the DC isolation devices is synchronously exited according to the exit status of the N switching switches, and determine whether the controller 1 has a communication failure according to the exit status of the N DC isolation exit status switches.

[0060] Among them, the camera module is used to obtain the first switch image and the second switch image, and output the first switch image and the second switch image taken in real time to the switch state monitoring model. The switch state monitoring model adopts a neural network with an encoder and a decoder structure. The trained switch state monitoring model can be used to predict the exit state of the switching switch and the exit state of the direct isolation exit state switch. The training process of the switch state monitoring model is: input the first switch image sample and the second switch image sample with the exit state label into the switch state monitoring model under the initial parameters, and use the cross loss entropy function to calculate the deviation between the prediction result of the switch state monitoring model and the exit state label. When the deviation reaches the preset condition, stop the model training, update the model parameters, and obtain the trained switch state monitoring model. The switch state monitoring model can realize the prediction of the switch exit state through a separate processor, or it can be realized through the controller 1.

[0061] The switch status monitoring model obtains the exit status of the switching switch and the exit status of the DC isolation exit status switch according to the first switch image and the second switch image and outputs them to the controller 1, and then outputs them to the control host 5 through the controller 1 to determine whether a communication failure occurs.

[0062] The working process of the above control circuit is: When the controller 1 of the DC isolation device detects that the DC current at the neutral point of the transformer connected thereto is less than 50A, that is, when the exit condition is met, the eighth port 108 of the controller sends a linkage exit control signal to the linkage exit control branch 9, so that the linkage exit control output switch is closed. When all the DC isolation devices meet the exit condition, the linkage exit control branches 9 of all the DC isolation devices form a DC isolation exit ring loop, and transmit the linkage exit control signal to the input end of the linkage exit input switch of the linkage exit control branch 9 of each DC isolation device through the DC isolation exit ring loop. The linkage exit input switch is closed after receiving the linkage exit control signal, and the linkage exit execution signal is sent to the controller 1 through the ninth port 109 of the controller. The ninth port 109 of the controller obtains the linkage exit execution signal output by the linkage exit control branch 9, and disconnects the switch on the transformer connection branch, so that the DC isolation device enters the exit state. When the controllers 1 of all the DC isolation devices detect that the DC isolation devices have entered the exit state, the tenth port 110 of the controller outputs the DC isolation exit state monitoring signal to the input end of the global exit state monitoring branch 11, and the DC isolation exit state switch is closed to disconnect the power signal. When all the DC isolation exit state switches are closed and all the power signals are disconnected, the DC isolation exit state monitoring signal (which is 0 at this time) is transmitted to the global exit state switch of each DC isolation device, and the global exit state switch is closed, and the global exit state monitoring signal is transmitted to the controller 1 through the eleventh port 111 of the controller. The controller 1 transmits the received DC isolation exit state monitoring signal to the control host 5, and the control host 5 determines that if the DC isolation exit state monitoring signal is 0, it is determined that the synchronous exit of the N DC isolation devices has been achieved; If a communication failure occurs when the tenth port 110 of the controller outputs the DC isolation exit state monitoring signal to the DC isolation exit state switch of the global exit state monitoring branch 11, and the DC isolation exit state switch is closed, the global exit state monitoring signal is 1, but the control host 5 does not receive the pending alarm signal, then the camera module obtains the first switch image of the switching switch on the transformer connection branch and the second image of the DC isolation exit state switch of the global exit state monitoring branch 11, and transmits them to the controller 1 through the seventh port of the controller. The controller 1 outputs the exit state of the switching switch and the exit state of the DC isolation exit state switch to the control host 5 through the trained switch state monitoring model. The control host 5 makes a judgment. If the exit state of the switching switch is disconnected, but the exit state of the DC isolation exit state switch is closed, the control host 5 determines that a communication failure occurs, but achieves synchronous exit. At this time, only the DC isolation device with a fault exits the system and is repaired, and other DC isolation devices that have exited remain in the exit state. After the faulty device exits the system, it will not affect the normal operation of other DC isolation devices in the system.

[0063] In this embodiment, a camera module is provided to obtain the first switch image and the second switch image and output them to the controller, thereby obtaining the exit state of the switching switch and the input state of the DC isolation exit state switch, and then outputting the exit state of the switching switch and the exit state of the DC isolation exit state switch to the monitoring host for judgment, thereby avoiding erroneous judgments due to communication failures, making the control circuit more perfect, ensuring that each DC isolation device is exited synchronously, suppressing the influence of DC current on the transformer, avoiding transformer failure due to DC bias magnetism, and extending the service life of the equipment.

[0064] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A control circuit for synchronously switching on and off of multiple transformer DC isolation devices, characterized in that: include: N DC isolation devices, wherein N>2, each of the DC isolation devices is cascade connected, and each of the DC isolation devices comprises: a controller, a linkage input control branch, and a transformer connection branch; The first port of the controller is connected to the input end of the linkage input control branch, and is used to send a linkage input control signal to the linkage input control branch. The second port of the controller is connected to the first output end of the linkage input control branch, and is used to obtain a linkage input execution signal. The third port of the controller is connected to the second output end of the linkage input control branch, and is used to provide a power supply signal to the linkage input control branch of other DC isolation devices through the second output end of the linkage input control branch. The controller is connected to the switching switch on the transformer connecting branch, and is used to control the switching switch on the transformer connecting branch to close according to the linkage input execution signal, so as to realize the synchronous input of the N DC isolation devices.

2. The control circuit according to claim 1, characterized in that: Each of the DC isolation devices also includes: a global input status monitoring branch, the input end of the global input status monitoring branch is connected to the fourth port of the controller, and is used to obtain the DC isolation input status monitoring signal output by the controller; the first output end of the global input status monitoring branch is connected to the fifth port of the controller, and is used to output the global input status monitoring signal to the controller; the second output ends of the global input status monitoring branches of each of the DC isolation devices are connected to form a DC isolation input status ring loop.

3. The control circuit according to claim 2, characterized in that: The global input status monitoring branch includes: a DC isolation input status switch and a global input status switch, the control end of the DC isolation input status switch serves as the input end of the global input status monitoring branch, the two ends of the DC isolation input status switch serve as the second output end of the global input status monitoring branch, the input end of the global input status switch is connected to the output end of the DC isolation input status switch, and the output end of the global input status switch serves as the first output end of the global input status monitoring branch.

4. The control circuit according to claim 3, characterized in that: Also includes: A control host is connected to the sixth port of the controller of each of the DC isolation devices, and is used to obtain a global startup status monitoring signal sent by each of the controllers, and determine whether the N DC isolation devices are synchronously started according to the N global startup status monitoring signals.

5. The control circuit according to claim 4, characterized in that: The DC isolation device further comprises: a camera module, the input end of which is used to obtain a first switch image including the switch on the transformer connection branch and a second switch image including the DC isolation input state switch of the global input state monitoring branch; The output end of the camera module is connected to the seventh port of the controller, and is used to input the first switch image and the second switch image into the trained switch state monitoring model, output the input state of the switching switch and the input state of the DC isolation input state switch to the controller, and send the input state of the switching switch and the input state of the DC isolation input state switch to the control host through the sixth port of the controller; The control host is used to determine whether each of the DC isolation devices is put into operation synchronously according to the operation status of the N switching switches, and to determine whether the controller has a communication failure according to the operation status of the N DC isolation operation status switches.

6. A control circuit for synchronously switching on and off of multiple transformer DC isolation devices, characterized in that: include: N DC isolation devices, wherein N>2, each of the DC isolation devices is cascade-connected, and each of the DC isolation devices comprises: a controller, a linkage exit control branch, and a transformer connection branch; The eighth port of the controller is connected to the input end of the linkage exit control branch, and is used to send a linkage exit control signal to the linkage exit control branch. The ninth port of the controller is connected to the first output end of the linkage exit control branch, and is used to obtain a linkage exit execution signal. The second output ends of the linkage exit control branches of the DC isolation devices are connected to each other to form a DC isolation exit ring loop. The controller is connected to the switching switch on the transformer connecting branch, and is used to control the switching switch on the transformer connecting branch to be disconnected according to the linkage exit execution signal, so as to realize the synchronous exit of the N DC isolation devices.

7. The control circuit according to claim 6, characterized in that: Each of the DC isolation devices also includes: a global exit status monitoring branch, the input end of the global exit status monitoring branch is connected to the tenth port of the controller, and is used to obtain the DC isolation exit status monitoring signal output by the controller; the first output end of the global exit status monitoring branch is connected to the eleventh port of the controller, and is used to output the global exit status monitoring signal to the controller; the twelfth port of the controller is connected to the second output end of the global exit status monitoring branch, and is used to obtain the global exit status monitoring signal of other DC isolation devices through the second output end of the global exit status monitoring branch.

8. The control circuit according to claim 7, characterized in that: The global exit status monitoring branch includes: a DC isolation exit status switch and a global exit status switch, the control end of the DC isolation exit status switch serves as the input end of the global exit status monitoring branch, one end of the DC isolation exit status switch is connected to the power supply of the DC isolation device, the other end of the DC isolation exit status switch serves as the second output end of the global exit status monitoring branch, the other end of the DC isolation exit status switch is also connected to the input end of the global exit status switch, and the output end of the global exit status switch serves as the first output end of the global exit status monitoring branch.

9. The control circuit according to claim 8, characterized in that: Also includes: A control host is connected to the sixth port of the controller of each of the DC isolation devices, and is used to obtain a global exit status monitoring signal sent by each of the controllers, and determine whether the N DC isolation devices exit synchronously according to the N global exit status monitoring signals.

10. The control circuit according to claim 9, characterized in that: The DC isolation device further comprises: a camera module, the input end of which is used to obtain a first switch image containing the switch on the transformer connection branch and a second switch image containing the DC isolation exit state switch of the global exit state monitoring branch; The output end of the camera module is connected to the seventh port of the controller, and is used to input the first switch image and the second switch image into the trained switch state monitoring model, output the exit state of the switching switch and the exit state of the DC isolation exit state switch to the controller, and send the exit state of the switching switch and the exit state of the DC isolation exit state switch to the control host through the sixth port of the controller; The control host is used to determine whether each of the DC isolation devices exits synchronously according to the exit status of the N switching switches, and determine whether the controller has a communication failure according to the exit status of the N DC isolation exit status switches.

Images