Controllable switch control method, circuit and related equipment

Abstract

The invention provides a controllable switch control method and circuit and related equipment, and is suitable for electrical equipment, the electrical equipment comprises a controllable switch, and the method comprises the following steps: when the controllable switch is in an off state, obtaining an electrical parameter of an output end of the controllable switch; when the electrical parameter reaches a specified trigger value, the controllable switch is controlled to be closed; the specified trigger value is obtained by correcting a trigger value used for controlling the controllable switch to be closed in a historical control closing process based on an impact signal generated in the historical control closing process of the controllable switch. In the scheme, in the process that the controllable switch is changed from the open state to the closed state every time, the detected impact signal generated in the closed process of the controllable switch is utilized to continuously correct the specified trigger value when the controllable switch is controlled to be closed next time, so that when the controllable switch is closed every time, the actual voltage zero crossing point is as close as possible, impact is reduced, and the reliability of the controllable switch is improved. The service life of the controllable switch is prolonged.

Description

[0001] This application claims the priority of a Chinese patent application with the application number 202311812729.4 and the invention title "Control Method and Circuit of a Controllable Switch", which was filed with the Chinese Patent Office on December 25, 2023. The entire content of this Chinese patent application is incorporated herein by reference. Technical Field

[0002] This application relates to the field of electrical technologies, and particularly to a control method, a circuit, and related devices for a controllable switch. Background Art

[0003] In the new energy industry, when energy sources such as photovoltaic, wind power, and energy storage are connected to the power grid through a power converter, a controllable switch with an obvious disconnection node, such as a relay, a circuit breaker, etc., needs to be connected to ensure that the device can be safely disconnected from the power grid in case of an abnormality. However, in specific applications, directly closing the controllable switch usually instantaneously charges the port capacitor due to the voltage difference across the controllable switch, which is likely to generate a large impact voltage and current, thereby affecting the service life of the controllable switch contacts. Summary of the Invention

[0004] In view of this, embodiments of this application provide a control method, a circuit, and related devices for a controllable switch to achieve the purpose of making the controllable switch close as close as possible to the true voltage zero-crossing point, reducing the impact, and improving the service life of the controllable switch.

[0005] To achieve the above purpose, embodiments of this application provide the following technical solutions:

[0006] A first aspect of embodiments of this application discloses a control method for a controllable switch, which is applicable to an electrical device. The electrical device includes a controllable switch. The method includes:

[0007] When the controllable switch is in the open state, obtain the electrical parameters at the output end of the controllable switch;

[0008] When the electrical parameters reach a specified trigger value, control the controllable switch to close;

[0009] Among them, the specified trigger value is obtained by correcting the trigger value used to control the closing of the controllable switch during the historical control closing process based on the impact signal generated during the historical control closing process of the controllable switch.

[0010] Optionally, the electrical parameters include a phase, and the specified trigger value includes a specified phase;

[0011] The obtaining of the electrical parameters at the output end of the controllable switch includes:

[0012] Obtain the voltage at the output end of the controllable switch;

[0013] Calculate the voltage at the output end of the controllable switch based on the phase-locked loop to obtain the phase at the output end of the controllable switch;

[0014] Correspondingly, when the electrical parameter reaches the specified trigger value, controlling the controllable switch to close includes:

[0015] When the phase at the output end of the controllable switch reaches the specified phase, send a closing instruction to the controllable switch to control the controllable switch to close.

[0016] Optionally, the electrical parameter includes voltage, and the specified trigger value includes a specified voltage;

[0017] Obtaining the electrical parameter at the output end of the control switch includes:

[0018] Obtain the voltage at the output end of the controllable switch;

[0019] Correspondingly, when the electrical parameter reaches the specified trigger value, controlling the controllable switch includes:

[0020] When the voltage at the output end of the controllable switch reaches the specified voltage, send a closing instruction to the controllable switch to control the controllable switch to close.

[0021] Optionally, during the process of controlling the controllable switch to close, it includes:

[0022] Detect whether a voltage impact signal is generated on the controllable switch side when the controllable switch closes;

[0023] If a voltage impact signal is generated, correct the specified trigger value of this time based on the voltage impact signal to obtain the specified trigger value for the next time to control the controllable switch to close;

[0024] If no voltage impact signal is generated, continue to use the specified trigger value of this time as the specified trigger value for the next time to control the controllable switch to close;

[0025] Alternatively, detect whether a current impact signal is generated on the controllable switch side when the controllable switch closes;

[0026] If a current impact signal is generated, correct the specified trigger value of this time based on the current impact signal to obtain the specified trigger value for the next time to control the controllable switch to close;

[0027] If no current impact signal is generated, continue to use the specified trigger value of this time as the specified trigger value for the next time to control the controllable switch to close.

[0028] Optionally, if the specified trigger value includes a specified phase, modifying the specified trigger value of this time based on the voltage impact signal to obtain the specified trigger value for controlling the controllable switch to close next time includes:

[0029] Determine the generation time of the voltage impact signal;

[0030] Determine the sending time of the closing instruction according to the specified phase of this time;

[0031] Calculate the actual closing time of the controllable switch according to the sending time of the closing instruction and the generation time of the voltage impact signal;

[0032] Calculate the phase change value according to the actual closing time of the controllable switch and the power grid cycle;

[0033] Modify the specified phase of this time by using the phase change value to obtain the specified trigger value for controlling the controllable switch to close next time.

[0034] Optionally, if the preset value includes a specified phase, modifying the specified trigger value of this time based on the voltage impact signal to obtain the specified trigger value for controlling the controllable switch to close next time includes:

[0035] Determine the polarity of the voltage impact signal and the phase interval in which the phase at the output end of the controllable switch is located;

[0036] Modify the specified phase of this time by using the determined phase adjustment step according to the polarity of the voltage impact signal and the phase interval to obtain the specified trigger value for controlling the controllable switch to close next time.

[0037] Optionally, modifying the specified phase of this time by using the determined phase adjustment step according to the polarity of the voltage impact signal and the phase interval to obtain the specified trigger value for controlling the controllable switch to close next time includes:

[0038] When the phase at the output end of the controllable switch is in the phase interval , and the polarity of the voltage impact signal is positive, obtain the determined phase adjustment step;

[0039] Use the sum value of the specified phase of this time and the phase adjustment step as the specified trigger value for controlling the controllable switch to close next time;

[0040] When the phase at the output end of the controllable switch is in the phase interval , and the polarity of the voltage impact signal is negative, obtain the determined phase adjustment step;

[0041] Use the difference between the specified phase this time and the phase adjustment step as the specified trigger value when controlling the closing of the controllable switch next time.

[0042] Optionally, according to the polarity of the voltage impact signal and the phase interval, use the determined phase adjustment step to correct the specified phase this time to obtain the specified trigger value when controlling the closing of the controllable switch next time, including:

[0043] When the phase at the output end of the controllable switch is in the phase interval or , and the polarity of the voltage impact signal is positive, obtain the determined phase adjustment step;

[0044] Use the difference between the specified phase this time and the phase adjustment step as the specified trigger value when controlling the closing of the controllable switch next time;

[0045] When the phase at the output end of the controllable switch is in the phase interval or , and the polarity of the voltage impact signal is negative, obtain the determined phase adjustment step;

[0046] Use the sum of the specified phase this time and the phase adjustment step as the specified trigger value when controlling the closing of the controllable switch next time.

[0047] Optionally, the determination process of the phase adjustment step includes:

[0048] Obtain the voltage impact value of the voltage impact signal, and determine the phase adjustment step according to the voltage impact value, where the phase adjustment step is positively correlated with the voltage impact value.

[0049] Optionally, if the specified trigger value includes a specified voltage, correcting the specified trigger value this time based on the voltage impact signal to obtain the specified trigger value when controlling the closing of the controllable switch next time includes:

[0050] Determine the polarity of the voltage impact signal;

[0051] If the polarity of the voltage impact signal is positive, use the difference between the specified voltage this time and the determined voltage adjustment step as the specified trigger value when controlling the closing of the controllable switch next time;

[0052] If the polarity of the voltage impact signal is negative, use the sum of the specified voltage this time and the determined voltage adjustment step as the specified trigger value when controlling the closing of the controllable switch next time.

[0053] Optionally, the determination process of the voltage adjustment step includes:

[0054] Obtain the voltage impact value of the voltage impact signal, and determine the voltage adjustment step according to the voltage impact value, where the voltage adjustment step is positively correlated with the voltage impact value.

[0055] Optionally, if the specified trigger value includes a specified phase, correcting the specified trigger value of this time based on the current impact signal to obtain the specified trigger value for controlling the controllable switch to close next time includes:

[0056] Determine the generation time of the current impact signal;

[0057] Determine the sending time of the closing instruction according to the specified phase of this time;

[0058] Calculate the actual closing time of the controllable switch according to the sending time of the closing instruction and the generation time of the current impact signal;

[0059] Calculate the phase change value according to the actual closing time of the controllable switch and the power grid cycle;

[0060] Use the phase change value to correct the specified phase of this time to obtain the specified trigger value for controlling the controllable switch to close next time.

[0061] Optionally, it further includes:

[0062] During the process of controlling the controllable switch to close multiple times, when the number of times that the amplitude of the phase change value exceeds the preset amplitude reaches the preset number of times, execute a switch fault alarm.

[0063] Optionally, if the specified trigger value includes a specified phase, it further includes:

[0064] Set the specified trigger value for sending the closing instruction for the first time according to the theoretical closing time of the controllable switch.

[0065] The second aspect of the embodiments of the present application discloses a control circuit for a controllable switch, and the control circuit includes: a controllable switch, a detection circuit, and a controller;

[0066] The input end of the controllable switch is connected to an electrical device, the output end of the controllable switch is connected to an input end of a power supply, and the other input end of the power supply is connected to the electrical device, to obtain a loop formed by the electrical device, the controllable switch, and the power supply;

[0067] The detection circuit is arranged at the input end or the output end of the controllable switch and is used to obtain the impact signal generated during the closing process of the controllable switch;

[0068] The input end of the controller is connected to the output end of the detection circuit, and the control end of the controller is connected to the movable end of the controllable switch. The controller is configured to execute the control method of the controllable switch disclosed in the first aspect of the embodiments of the present application.

[0069] Optionally, the detection circuit includes a voltage detection circuit or a current detection circuit.

[0070] Optionally, there is one or more controllable switches connected in series in the loop, and the controllable switch includes a relay or a circuit breaker.

[0071] The third aspect of the embodiments of the present application discloses a power converter, and the power converter includes the control circuit of the control switch disclosed in the second aspect of the embodiments of the present application.

[0072] The fourth aspect of the embodiments of the present application discloses a new energy system, and the new energy system includes the power converter disclosed in the third aspect of the embodiments of the present application.

[0073] Based on the control method, circuit and related equipment of a controllable switch provided in the embodiments of the present invention above, which are applicable to electrical equipment, and the electrical equipment at least includes a controllable switch. The method includes: when the controllable switch is in an open state, acquiring the electrical parameters at the output end of the controllable switch; when the electrical parameters reach a specified trigger value, controlling the controllable switch to close; the specified trigger value is obtained by correcting the trigger value used to control the closing of the controllable switch in the historical control closing process based on the impact signal generated during the historical control closing process of the controllable switch. In this solution, during each process of the controllable switch changing from an open state to a closed state, the detected impact signal generated during the closing process of the controllable switch is used to continuously correct the specified trigger value for controlling the closing of the controllable switch next time, so that each time the controllable switch closes, it is as close as possible to the true voltage zero crossing, reducing the impact and increasing the service life of the controllable switch. Description of the Drawings

[0074] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0075] Figure 1 It is a schematic diagram of a typical application scenario of a relay provided by the embodiments of the present application;

[0076] Figure 2 It is a schematic diagram of an application scenario of a controllable switch control circuit provided by the embodiments of the present application;

[0077] Figure 3 Schematic diagram of a control method for a controllable switch provided by an embodiment of the present application;

[0078] Figure 4 Schematic diagram of another control method for a controllable switch provided by an embodiment of the present application;

[0079] Figure 5 Schematic diagram of still another control method for a controllable switch provided by an embodiment of the present application;

[0080] Figure 6 Control timing diagram for judging voltage impact on a controllable switch provided by an embodiment of the present application;

[0081] Figure 7 Schematic diagram of yet another control method for a controllable switch provided by an embodiment of the present application;

[0082] Figure 8 Control timing diagram for judging current impact on a controllable switch provided by an embodiment of the present application;

[0083] Figure 9 Schematic diagram of still another control method for a controllable switch provided by an embodiment of the present application;

[0084] Figure 10 Timing diagram for adjusting a specified phase provided by an embodiment of the present application;

[0085] Figure 11 Schematic diagram of another control method for a controllable switch provided by an embodiment of the present application;

[0086] Figure 12 Timing diagram for adjusting a specified voltage provided by an embodiment of the present application;

[0087] Figure 13 Schematic diagram of the structure of a control circuit for a controllable switch provided by an embodiment of the present application;

[0088] Figure 14 Schematic diagram of the structure of another control circuit for a controllable switch provided by an embodiment of the present application. Detailed implementation manners

[0089] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0090] In this application, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of additional identical elements in the process, method, article or device comprising said element.

[0091] As Figure 1 shown, it is a schematic diagram of a typical application scenario of a controllable switch. On the left side is a converter or other grid load, and on the right side is the grid. In Figure 1 the shown application scenario, it is usually adopted to detect the zero-crossing point of the current on the grid side of the controllable switch, and under the condition of compensating for a constant action delay Ts of the controllable switch (action time Ts: when a control signal is sent to the controllable switch, it takes a period of time for the controllable switch to respond and achieve closing, and this period of time is the action time Ts of the controllable switch), a method of connecting both ends as close as possible at the zero-crossing point is realized as much as possible. However, due to different types of controllable switches, their corresponding action times Ts are also different, resulting in poor applicability of this method, and still unable to make the controllable switch close as close as possible to the true voltage zero-crossing point to avoid generating a large impact voltage and current.

[0092] It can be seen from this that the existing control methods for controllable switches not only have poor applicability, but also cannot make the controllable switch close as close as possible to the true voltage zero-crossing point, cannot reduce the impact, and affect the service life of the controllable switch.

[0093] Therefore, the embodiments of this application provide a control method, circuit and related device for a controllable switch. In this application, during the process of each time the controllable switch is controlled to change from the off state to the on state, the detected impact signal on the controllable switch side is used to continuously correct the specified trigger value when the controllable switch is controlled to close next time, so that each time the controllable switch closes as close as possible to the true voltage zero-crossing point, reducing the impact, even without impact, and further improving the service life of the controllable switch.

[0094] As Figure 2 shown, it is a schematic diagram of an application scenario of a control method for a controllable switch provided by an embodiment of this application. The controllable switch can be used to connect an electrical device and a power supply. The application scenario is as follows:

[0095] The electrical device is load 20, the power supply is grid 21, and the control circuit 22 of the controllable switch is arranged between load 20 and grid 21. When load 20 is connected to grid 21, the control circuit 22 of the controllable switch can safely disconnect load 20 from grid 21 in case of an abnormality.

[0096] Optionally, the control circuit 22 of the controllable switch at least includes a controllable switch, a detection circuit connected to one end of the output terminal of the controllable switch, or a detection circuit at both the input terminal and the output terminal, and a controller connected to the detection circuit.

[0097] Optionally, there is one or more series-connected controllable switches in the control circuit 22 of the controllable switch.

[0098] Optionally, the controllable switch includes a relay or a circuit breaker.

[0099] Optionally, if the controllable switch is a controllable switch in a power converter, the controller connected to the detection circuit is a controller in the power converter. Optionally, the power converter can be an inverter, specifically a grid-connected inverter.

[0100] As Figure 3 shown, it is a schematic flowchart of a control method for a controllable switch provided by an embodiment of the present application. The control method for the controllable switch is applicable to an electrical device. The electrical device includes a controllable switch. The control method for the controllable switch includes:

[0101] Step S301: When the controllable switch is in the off state, obtain the electrical parameters at the output terminal of the controllable switch.

[0102] In step S301, the controllable switch includes a relay or a circuit breaker.

[0103] In the specific process of executing step S301, within a preset time period before the controllable switch needs to be controlled to close, when the controllable switch is in the off state, detect the electrical parameters at the output terminal of the controllable switch before the controllable switch closes.

[0104] In an embodiment of the present application, if the electrical parameter is voltage, directly obtain the voltage at the output terminal of the controllable switch when the controllable switch is in the off state.

[0105] In an embodiment of the present application, if the electrical parameter is phase, when the controllable switch is in the off state, obtain the voltage at the output terminal of the controllable switch, and calculate the phase at the output terminal of the controllable switch based on a phase-locked loop.

[0106] In an embodiment of the present application, if the electrical parameter is phase and the output terminal of the controllable switch is connected to the power grid, when the controllable switch is in the off state, obtain the voltage of the power grid connected to the output terminal of the controllable switch, and calculate the phase of the power grid based on a phase-locked loop, that is, obtain the electrical parameter at the output terminal of the controllable switch.

[0107] Step S302: When the electrical parameter reaches a specified trigger value, control the controllable switch to close.

[0108] In step S302, the specified trigger value is an adjustable value. The specified trigger value is initially the factory setting value of the controllable switch, and the factory setting value can be an empirical value or an engineering calculation value.

[0109] Among them, the specified trigger value includes a specified phase or a specified voltage. Specifically, the specified trigger value is obtained by correcting the trigger value used to control the closing of the controllable switch in the historical control closing process based on the impact signal generated during the historical control closing process of the controllable switch. Among them, the trigger value used to control the closing of the controllable switch can be understood as the "specified trigger value" used in the historical control closing process, and its role in the historical control closing process is the same as that of the specified trigger value in this step in the current control of the controllable switch closing process.

[0110] It should be noted that the above historical control closing process can be the first N closing processes of the controllable switch, where N is a positive integer greater than or equal to 0. Optionally, in order to further improve the accuracy, the above historical control closing process can be the previous closing control process of the current closing control process. At this time, the specified trigger value used in the current closing control process is: obtained by correcting the trigger value used to control the closing of the controllable switch (which can also be called the specified trigger value in the previous closing control process, and the two are the same, and will not be specifically stated later) in the previous closing control process based on the impact signal of the previous closing control process.

[0111] In the specific execution of S302, when the electrical parameters reach the specified phase or the specified voltage, a closing instruction is sent to the controllable switch to control the closing of the controllable switch.

[0112] In an embodiment of the present application, if this is the initial control of the controllable switch, the specified trigger value is the factory setting value. When the electrical parameters reach the factory setting value, a closing instruction is sent to the controllable switch, and it is obtained that the controllable switch closes based on this closing instruction.

[0113] In an embodiment of the present application, after sending the closing instruction to the controllable switch, it is detected whether a voltage impact signal or a current impact signal is generated on the side of the controllable switch.

[0114] If a voltage impact signal is generated, the specified trigger value of this time is corrected based on this voltage impact signal to obtain the specified trigger value for the next control of the controllable switch to close.

[0115] If no voltage impact signal is generated, the specified trigger value of this time is continued to be used as the specified trigger value for the next control of the controllable switch to close.

[0116] If a current impact signal is generated, the specified trigger value of this time is corrected based on the current impact signal to obtain the specified trigger value for the next control of the controllable switch to close.

[0117] If no voltage impact signal is generated, continue to use the specified trigger value of this time as the specified trigger value for controlling the closing of the controllable switch next time.

[0118] That is to say, when the controllable switch is closed this time, by detecting the voltage or current on the controllable switch side, when it is determined that the power supply generates a voltage impact signal or a current impact signal on the electrical equipment, a new specified trigger value is obtained by correcting the specified trigger value of this time. When it is necessary to control the closing of the controllable switch next time, when the electrical parameters reach the new specified trigger value, a closing instruction is sent to the controllable switch to control the closing of the controllable switch. Based on this, the specified trigger value for sending the closing instruction next time is continuously corrected by using the detected impact signal, so that each time the controllable switch is closed, it is as close as possible to the true voltage zero crossing, reducing the impact, or even having no impact, and further improving the service life of the controllable switch.

[0119] In an embodiment of the present application, if the specified trigger value is a specified phase, the process of correcting the specified trigger value of this time based on the voltage impact signal to obtain the specified trigger value for controlling the closing of the controllable switch next time includes:

[0120] Determine the generation time of the voltage impact signal; determine the sending time of the closing instruction according to the specified phase of this time; calculate the actual closing time of the controllable switch according to the sending time of the closing instruction and the generation time of the voltage impact signal; calculate the phase change value according to the actual closing time of the controllable switch and the power grid cycle; use the phase change value to correct the specified phase of this time to obtain the specified trigger value for controlling the closing of the controllable switch next time.

[0121] In an embodiment of the present application, if the specified trigger value is a specified phase, the process of correcting the specified trigger value of this time based on the voltage impact signal to obtain the specified trigger value for controlling the closing of the controllable switch next time includes:

[0122] Determine the polarity of the voltage impact signal and the phase interval where the phase of the output end of the controllable switch is located; correct the specified phase of this time by using the determined phase adjustment step according to the polarity of the voltage impact signal and the phase interval to obtain the specified trigger value for controlling the closing of the controllable switch next time.

[0123] In an embodiment of the present application, if the specified trigger value is a specified voltage, the process of correcting the specified trigger value of this time based on the voltage impact signal to obtain the specified trigger value for controlling the closing of the controllable switch next time includes:

[0124] Determine the polarity of the voltage impact signal; if the polarity of the voltage impact signal is positive, use the difference between the specified voltage this time and the determined voltage adjustment step as the specified trigger value when controlling the closing of the controllable switch next time; if the polarity of the voltage impact signal is negative, use the sum of the specified voltage this time and the determined voltage adjustment step as the specified trigger value when controlling the closing of the controllable switch next time.

[0125] In an embodiment of the application, if the specified trigger value is the specified phase, the process of correcting the specified trigger value this time based on the current impact signal to obtain the specified trigger value when controlling the closing of the controllable switch next time includes:

[0126] Determine the generation time of the current impact signal; determine the sending time of the closing instruction according to the specified phase this time; calculate the actual closing time of the controllable switch according to the sending time of the closing instruction and the generation time of the current impact signal; calculate the phase change value according to the actual closing time of the controllable switch and the power grid cycle; use the phase change value to correct the specified phase this time to obtain the specified trigger value when controlling the closing of the controllable switch next time.

[0127] Based on the control method of the control switch disclosed in the embodiments of the present application, continuously correct the specified trigger value when controlling the closing of the controllable switch next time by using the detected impact signal, so that each time the controllable switch closes, it is as close as possible to the true voltage zero crossing, reducing impact, or even having no impact, and further improving the service life of the controllable switch.

[0128] As Figure 4 shown, it is a schematic flowchart of another control method of the controllable switch provided by the embodiment of the present application. This control method of the controllable switch is applicable to electrical equipment, and the electrical equipment includes a controllable switch. The control method of the controllable switch mainly includes the following steps:

[0129] Step S401: When the controllable switch is in the off state, obtain the power grid parameters of the power grid connected to the output end of the controllable switch.

[0130] In step S401, the power grid parameters include the phase of the power grid or the voltage of the power grid.

[0131] In step S401, the controllable switch includes a relay or a circuit breaker.

[0132] In the process of specifically implementing step S401, within a preset time period before the controllable switch needs to be controlled to close, detect the state of the controllable switch. When it is detected that the controllable switch is in the off state, the power grid parameters of the power grid connected to the output end of the controllable switch can be obtained through detection. The power grid parameters are equivalent to electrical parameters.

[0133] In an embodiment of the present application, if the obtained power grid parameter is voltage, specifically when the controllable switch is in the open state, the power grid parameter of the power grid connected to the output end of the controllable switch is obtained as follows:

[0134] When the controllable switch is in the open state, obtain the voltage of the power grid connected to the output end of the controllable switch.

[0135] In an embodiment of the present application, if the obtained power grid parameter is phase, specifically when the controllable switch is in the open state, the power grid parameter of the power grid connected to the output end of the controllable switch is obtained as follows:

[0136] First, when the controllable switch is in the open state, obtain the voltage of the power grid connected to the output end of the controllable switch; second, calculate the phase of the power grid based on the phase-locked loop for the voltage of the power grid to obtain the phase of the power grid.

[0137] It should be noted that the phase of the power grid is normally in the linear interval of [0, 2π].

[0138] Step S402: When the power grid parameter reaches the specified trigger value determined for the previous issued closing instruction, control the controllable switch to close.

[0139] In step S402, the specified trigger value refers to the value that triggers the controllable switch to close. When the power grid parameter reaches the specified trigger value, a closing instruction is issued. The specified trigger value can be adjusted.

[0140] It should be noted that the initial value of the specified trigger value can be the value set at the factory, and the value set at the factory can be an empirical value or an engineering calculation value.

[0141] Optionally, the specified trigger value can be a specified phase or a specified voltage. If the specified trigger value is a specified phase, the power grid parameter obtained when executing step S401 is the phase of the power grid. If the specified trigger value is a specified voltage, the power grid parameter obtained when executing step S401 is the voltage of the power grid.

[0142] In the specific process of executing step S402, compare the power grid parameter with the specified trigger value determined for the previous issued closing instruction. If the power grid parameter reaches the specified trigger value determined for the previous issued closing instruction, control the controllable switch to close.

[0143] In an embodiment of the present application, if the specified trigger value is a specified phase, the power grid parameter obtained by executing step S401 includes the phase of the power grid. In the specific process of executing step S402, when the phase of the power grid reaches the specified phase of the currently issued closing instruction, control the controllable switch to close.

[0144] In an embodiment of the present application, if the specified trigger value is the specified voltage, the grid parameters obtained by executing step S401 include the voltage of the grid. During the specific execution of step S402, when the voltage of the grid reaches the specified voltage of the currently issued closing instruction, the controllable switch is controlled to close.

[0145] In step S402, the specified trigger value for the previously determined issued closing instruction is obtained by correcting the specified trigger value for triggering the issued closing instruction based on the impact signal when it is detected that an impact signal is generated at the input end and / or the output end of the controllable switch during the process of changing the controllable switch from the off state to the on state. That is, the previously determined specified trigger value is used as the specified trigger value for the currently issued closing instruction. If it is the first time to issue a closing instruction, the specified trigger value for the currently issued closing instruction is the initial value.

[0146] In an embodiment of the present application, after executing step S402, it further includes performing a specified trigger value calibration operation, and this specified trigger value calibration operation includes:

[0147] During the process of changing the controllable switch from the off state to the on state, it is detected whether an impact signal is generated at the input end or the output end of the controllable switch. If an impact signal is generated at any end, the specified trigger value for the previously determined issued closing instruction is corrected based on this impact signal, and the corrected specified trigger value is used as the specified trigger value for the next issued closing instruction. If no impact signal is generated at any end, it means that the closing of the controllable switch gradually approaches the true zero crossing point, and there is no need to correct the specified trigger value for the next issued closing instruction. The current specified trigger value, that is, the specified trigger value for the previously determined issued closing instruction, is still used as the specified trigger value for the next issued closing instruction.

[0148] It should be noted that at the moment when the controllable switch closes, if the voltage or current at the input end or the output end of the controllable switch is different and an impact is generated, it means that the closing of the controllable switch does not approach the true zero crossing point, and it is necessary to correct the specified trigger value for the next issued closing instruction to ensure that each time the controllable switch closes, it is as close as possible to the true voltage zero crossing point, reduce the impact, and improve the service life of the controllable switch.

[0149] In an embodiment of the present application, the process of specifically performing the specified trigger value calibration operation includes:

[0150] During the process of changing the controllable switch from the off state to the on state, it is detected whether a voltage impact signal is generated at the input end or the output end of the controllable switch;

[0151] If a voltage impact signal is generated at any end of the input end and the output end of the controllable switch, the specified trigger value for the previously determined issued closing instruction is corrected based on the voltage impact signal to obtain the specified trigger value for the next issued closing instruction;

[0152] If no voltage impact signal is generated at either the input end or the output end of the controllable switch, continue to use the specified trigger value determined in the previous time for issuing the closing command as the specified trigger value for issuing the closing command in the next time.

[0153] In an embodiment of the present application, the process of specifically performing the specified trigger value calibration operation includes:

[0154] During the process of the controllable switch changing from the off state to the on state, detect whether a current impact signal is generated at the input end or the output end of the controllable switch;

[0155] If a current impact signal is generated at either the input end or the output end of the controllable switch, correct the specified trigger value of the closing command determined in the previous time based on the current impact signal to obtain the specified trigger value of the closing command in the next time;

[0156] If no current impact signal is generated at either the input end or the output end of the controllable switch, continue to use the specified trigger value determined in the previous time for issuing the closing command as the specified trigger value for issuing the closing command in the next time.

[0157] Based on the control method of a controllable switch provided in the above embodiment of the present application, during each process of the controllable switch changing from the off state to the on state, continuously correct the specified trigger value of the closing command issued in the next time by using the detected impact signal at both ends of the controllable switch, so as to ensure that each time the controllable switch is closed, it is as close as possible to the true voltage zero crossing point, reduce impact, and improve the service life of the controllable switch.

[0158] Based on the control method of a controllable switch provided in the above embodiment of the present application, as Figure 5 shown, it is a schematic flowchart of another control method of a controllable switch provided in an embodiment of the present application. In this embodiment, the specified trigger value is the specified phase. It should be noted that the following content related to the phase and the specified phase can be applied to Figure 3 the disclosed control method of the controllable switch.

[0159] The control method of the controllable switch mainly includes the following steps:

[0160] Step S501: When the controllable switch is in the off state, obtain the phase of the power grid connected to the output end of the controllable switch.

[0161] During the specific execution of S501, first, when the controllable switch is in the off state, obtain the voltage of the power grid connected to the output end of the controllable switch; then, calculate the phase of the power grid based on the phase-locked loop for the voltage of the power grid.

[0162] Step S502: When the phase of the power grid reaches the specified phase at which the closing instruction was determined previously, control the controllable switch to close.

[0163] In step S502, when the specified trigger value is the specified phase, the first selection of the specified phase can be arbitrary. The specified phase for the first issuance of the closing instruction can also be set according to the theoretical closing time of the controllable switch.

[0164] For example, if the theoretical closing time of the controllable switch in a certain power range is 5 ms and the power grid period is 20 ms, the specified phase θ0 for the first issuance of the closing instruction can be .

[0165] Step S503: During the process of the controllable switch changing from the open state to the closed state, detect whether a voltage impact signal is generated at the input end or the output end of the controllable switch. If a voltage impact signal is generated, execute S504; if no voltage impact signal is generated, execute S509.

[0166] In step S503, when detecting the voltage at the input end or the output end of the controllable switch, the impact signal is the voltage impact signal.

[0167] It should be noted that the phase of the power grid is normally in the linear interval of [0, 2π]. As Figure 6 shown, assume that the issuing moment of the closing instruction corresponding to the specified phase is the moment of the phase of the power grid, , corresponding to the time series t0. In practical applications, the controllable switch actually closes after the action delay Ts. Due to the inaccuracy of the moment of triggering the controllable switch to close and the uncertainty of the delay Ts time, it is very likely that the controllable switch does not close at the zero point of the power grid, and a part of the impact will be generated. Therefore, in the embodiment of the present invention, during the execution of step S503, if a voltage impact signal is detected at the input end or the output end of the controllable switch, the moment of triggering the controllable switch to close next time needs to be adjusted. In the embodiment of the present application, the specified phase needs to be adjusted.

[0168] Step S504: Determine the generation moment of the voltage impact signal.

[0169] Based on Figure 6 the example shown, during the specific execution of step S604, after the action delay Ts, the generation moment of the voltage impact signal is determined to be t1.

[0170] Step S505: Determine the issuing moment of the closing instruction according to the specified phase.

[0171] Based on Figure 6 the example shown, during the specific execution of step S505, the specified phase is At this time, the issuing time of the current closing instruction is t0.

[0172] It should be noted that when the controllable switch closing control is not performed for the first time, the specified phase may have been adjusted.

[0173] Step S506: Calculate the actual closing time of the controllable switch according to the issuing time of the closing instruction and the generating time of the voltage impact signal.

[0174] In step S506, the actual closing time of the controllable switch is the action delay Ts of the current controllable switch.

[0175] In the specific implementation process of step S506, calculate the difference between the generating time t1 of the voltage impact signal and the issuing time t0 of the closing instruction, that is: This difference is the actual closing time of the controllable switch.

[0176] Based on Figure 6 the example shown, assume that the voltage at the input end of the controllable switch is detected as an example, and a voltage impact signal is detected.

[0177] Step S507: Calculate the phase change value according to the actual closing time of the controllable switch and the power grid cycle.

[0178] In the specific execution process of step S507, based on formula (1), use the actual closing time of the controllable switch and the power grid cycle for conversion to obtain the phase change value θs.

[0179] (1)

[0180] where T is the power grid cycle and Ts is the actual closing time of the controllable switch.

[0181] Step S508: Use the phase change value to correct the specified phase of the previously determined issuing closing instruction to obtain the specified trigger value for the next issuing closing instruction.

[0182] In the specific execution process of step S508, according to formula (2), use the phase change value θs to correct the specified phase of the previously determined issuing closing instruction to obtain the specified trigger value for the next issuing closing instruction .

[0183] (2)

[0184] where k ≥ 1.

[0185] Step S509: Continue to use the specified trigger value of the previously determined issuing closing instruction as the specified trigger value for the next issuing closing instruction.

[0186] If no voltage impact signal is generated, step S509 is executed, indicating that the current controllable switch is closing gradually approaching the true zero crossing point, and there is no need to correct the specified trigger value for the next issued closing command. When the controllable switch changes from the off state to the on state next time, the specified trigger value determined in the previous time is still used to determine the time to issue the closing command.

[0187] In an embodiment of the present application, in order to avoid the change of the action delay Ts of the controllable switch during long-term use of the controllable switch, resulting in the initial specified trigger value no longer being applicable, during the execution of the controllable switch control method disclosed in the embodiments of the present invention, each time the controllable switch is closed, the phase change value is recalculated, and the specified trigger value (specified phase) is continuously corrected and updated by using the phase change value, so that the controllable switch can accurately close at the zero crossing each time.

[0188] It should be noted that in actual application, through the first accurate calculation, when closing for the second time, it is very likely to just fall on the zero crossing point without generating an impact, so it may not be possible to capture the new action delay. At this time, in the ideal case, the specified trigger value (specified phase) can be kept as the previous specified trigger value.

[0189] In an embodiment of the present application, during the process of executing the above steps S501 to S508 multiple times, that is, during the process of controlling the controllable switch to close multiple times, if the number of times the amplitude of the phase change value exceeds the preset amplitude reaches the preset number of times, a controllable switch fault alarm is executed.

[0190] For example, the preset amplitude is π / 20 and the preset number of times is 2 times. That is, during the process of controlling the controllable switch to close multiple times, if the amplitude of the phase change value exceeds π / 20 twice, a controllable switch fault alarm is executed.

[0191] For example, the preset amplitude is π / 20 and the preset number of times is 5 times. That is, during the process of controlling the controllable switch to close multiple times, if the amplitude of the phase change value exceeds π / 20 five times, a controllable switch fault alarm is executed.

[0192] Based on the control method of the controllable switch disclosed in the embodiments of the present application, when the controllable switch is in the open state, the phase of the power grid connected to the output end of the controllable switch is acquired; when the phase of the power grid reaches the specified phase for issuing the closing instruction determined last time, the controllable switch is controlled to close; during the process of the controllable switch changing from the open state to the closed state, when a voltage impact signal is detected at the input end and / or the output end of the controllable switch, the specified phase for issuing the closing instruction determined last time is corrected based on the voltage impact signal to obtain the specified phase for issuing the closing instruction next time. In the present application, during the process of each change of the controllable switch from the open state to the closed state, the specified phase for issuing the closing instruction next time is continuously corrected by using the voltage impact signal detected at any end of the controllable switch, so that the controllable switch can be close to the true voltage zero crossing point each time it closes, reducing the impact and improving the service life of the controllable switch.

[0193] The above embodiments take capturing the voltage impact signal at any end of the controllable switch as an example. In the embodiments of the present application, the current impact signal at any end of the controllable switch can also be captured, such as Figure 7 shown, which is a schematic flowchart of another control method of the controllable switch provided by the embodiments of the present application. It should be noted that the following content related to the phase and the specified phase can be applied to Figure 3 the control method of the control switch disclosed.

[0194] The control method of the controllable switch mainly includes the following steps:

[0195] Step S701: When the controllable switch is in the open state, acquire the phase of the power grid connected to the output end of the controllable switch.

[0196] Step S702: When the phase of the power grid reaches the specified phase for issuing the closing instruction determined last time, control the controllable switch to close.

[0197] Step S703: During the process of the controllable switch changing from the open state to the closed state, detect whether a current impact signal is generated at the input end or the output end of the controllable switch. If a current impact signal is generated, execute S704; if no current impact signal is generated, execute S709.

[0198] In step S703, when detecting the current at the input end or the output end of the controllable switch, the impact signal is the current impact signal.

[0199] Step S704: Determine the generation moment of the current impact signal.

[0200] Step S705: Determine the issuing moment of the closing instruction according to the specified phase.

[0201] Step S706: Calculate the actual closing time of the controllable switch according to the sending time of the closing instruction and the generation time of the current impact signal.

[0202] Step S707: Calculate the phase change value according to the actual closing time of the controllable switch and the power grid cycle.

[0203] Step S708: Use the phase change value to correct the specified phase of the previously determined closing instruction to obtain the specified trigger value for the next sending of the closing instruction.

[0204] Step S709: Continue to use the specified trigger value of the previously determined closing instruction as the specified trigger value for the next sending of the closing instruction.

[0205] It should be noted that the execution principles and processes of the above steps S701 to S709 are similar to those of steps S501 to S509 disclosed in Figure 5 , which can be referred to and will not be elaborated here.

[0206] For a better understanding of the above content, as Figure 8 shown, it is a control timing diagram for judging the current impact received by the controllable switch provided by an embodiment of the present application.

[0207] Among them, the sending instruction of the closing instruction corresponding to the specified phase is the θ0 moment of the phase of the power grid, , corresponding to the time sequence t0, and t2 is the generation time of the current impact signal. The actual closing time of the controllable switch is: Ts = (t2 - t0).

[0208] Based on formula (1) and formula (2), the specified trigger value for the next sending of the closing instruction can be obtained .

[0209] Based on the controllable switch control method provided by the above embodiment of the present application, when the controllable switch is in the off state, obtain the phase of the power grid connected to the output end of the controllable switch; when the phase of the power grid reaches the specified phase of the previously determined closing instruction, control the controllable switch to close; during the process of the controllable switch changing from the off state to the closed state, when a current impact signal is detected at the input end and / or output end of the controllable switch, correct the specified phase of the previously determined closing instruction based on the current impact signal to obtain the specified phase of the next sending of the closing instruction. In the present application, during the process of each change of the controllable switch from the off state to the closed state, the specified phase of the next sending of the closing instruction is continuously corrected by using the current impact signal detected at any end of the controllable switch, so that each time the controllable switch closes, it is as close as possible to the true voltage zero crossing, reducing the impact and improving the service life of the controllable switch.

[0210] It should be noted that based on the control method of the controllable switch disclosed in the above embodiments of the present application, regardless of the type or signal of the controllable switch and whether it has a feedback node, it can be automatically adapted. Since the action delay Ts is detected online, it can ensure that the closing action of the controllable switch occurs as close as possible to the true zero crossing point, thereby improving the service life.

[0211] Based on the control method of the controllable switch provided in the above embodiments of the present application, the action delay can be directly obtained, and then the specified phase can be adjusted based on this value. The control method of the controllable switch disclosed in the embodiments of the present application is not limited to adjusting the specified phase by using the action delay. As Figure 9 shown, if the specified trigger value is the specified phase, it is a schematic flowchart of another control method of the controllable switch provided in the embodiments of the present application. The control method of the controllable switch mainly includes the following steps:

[0212] Step S901: When the controllable switch is in the off state, obtain the phase of the power grid connected to the output end of the controllable switch.

[0213] Step S902: When the phase of the power grid reaches the specified phase for issuing the closing instruction determined last time, control the controllable switch to close.

[0214] Step S903: During the process of the controllable switch changing from the off state to the on state, detect whether a voltage impact signal is generated at the input end or the output end of the controllable switch. If a voltage impact signal is generated, execute S904; if no voltage impact signal is generated, execute S906.

[0215] The specific execution process and principle of the above steps S901 to S903 are the same as those of Figure 5 the steps S501 to S503 shown, which can be referred to and will not be elaborated here.

[0216] Step S904: Determine the polarity of the voltage impact signal and the phase interval in which the phase of the power grid is located.

[0217] In step S904, the polarity of the voltage impact signal is positive or negative. By determining the positive or negative polarity of the voltage impact signal, it can be determined which end of the controllable switch the voltage impact occurs when the controllable switch closes.

[0218] In step S904, the phase interval in which the phase of the power grid is located is determined by the change of the power grid voltage when the voltage impact is generated. Assume that a voltage impact signal is generated at the input end of the controllable switch. If the power grid voltage change is negative growth, that is, from large to small, then the phase interval in which the phase of the power grid is located is . If the power grid voltage change is positive growth, that is, from small to large, then the phase interval in which the phase of the power grid is located is .

[0219] Step S905: According to the polarity and phase interval of the voltage impact signal, use the determined phase adjustment step size to correct the specified phase of the previously determined issued closing instruction, and obtain the specified trigger value of the next issued closing instruction.

[0220] Step S906: Continue to use the specified trigger value of the previously determined issued closing instruction as the specified trigger value of the next issued closing instruction.

[0221] In step S905, the process of determining the phase adjustment step size is as follows: Obtain the voltage impact value of the voltage impact signal, and determine the phase adjustment step size according to the voltage impact value.

[0222] For example, when the voltage impact value is large, the phase adjustment step size will be larger; when the voltage impact value is small, the phase adjustment step size will be smaller, gradually approaching the true zero-crossing point.

[0223] Specifically, the phase adjustment step size is positively correlated with the voltage impact value. Specifically, as shown in formula (3).

[0224] (3)

[0225] Wherein, is the phase adjustment step size, is the voltage impact value, k≥1.

[0226] In an embodiment of the present application, the specific process of executing step S905:

[0227] Step S9051: When the phase of the power grid is in the phase interval , determine whether the polarity of the voltage impact signal is positive. If it is positive, execute step S9052; if it is negative, execute step S9054.

[0228] In the process of specifically executing step S9051, when it is determined that the phase of the power grid is in the phase interval , if the polarity of the voltage impact signal is positive, it indicates that the actual closing moment of the controllable switch occurs on the left side of the theoretical position . The specified phase of the previously determined issued closing instruction should be shifted to the right, that is, increase a phase adjustment step size to compensate for the generated offset, that is, execute step S9052.

[0229] If the polarity of the voltage impact signal is negative, it indicates that the actual closing moment of the controllable switch occurs on the right side of the theoretical position . The specified phase of the previously determined issued closing instruction should be shifted to the left, that is, reduce a phase adjustment step size , to compensate for the generated offset, step S9054 is executed.

[0230] Step S9052: Determine the phase adjustment step size.

[0231] During the specific execution of step S9052, a phase adjustment step size is generated according to formula (3) .

[0232] Step S9053: Use the sum of the specified phase of the previously determined closing command and the phase adjustment step size as the specified trigger value for the next issued closing command.

[0233] During the specific execution of step S9053, obtain the specified phase of the previously determined closing command and the phase adjustment step size of the sum , use this sum as the specified trigger value for the next issued closing command.

[0234] Step S9054: Determine the phase adjustment step size.

[0235] During the specific execution of step S9054, a phase adjustment step size is generated according to formula (3) .

[0236] Step S9055: Use the difference between the specified phase of the previously determined closing command and the phase adjustment step size as the specified trigger value for the next issued closing command.

[0237] During the specific execution of step S9055, obtain the specified phase of the previously determined closing command and the phase adjustment step size of the difference , use this difference as the specified trigger value for the next issued closing command.

[0238] Taking Figure 10 as an example, assume that the issuing moment of the closing command corresponding to the specified phase is at the moment of the phase of the power grid, , at this time, a voltage impact signal is generated at the input end of the controllable switch, and the power grid voltage changes to negative growth. At this time, the phase interval where the phase of the power grid is located is , according to the polarity judgment of the voltage impact signal, the following adjustment logic is obtained:

[0239] When is true,

[0240] (1) The polarity of the voltage impact signal is positive, and the specified trigger value (action moment) for the next issued closing command is: ;

[0241] (2) The polarity of the voltage impact signal is negative, and the specified trigger value (action moment) for the next issued closing instruction is: .

[0242] In an embodiment of the present application, the process of specifically executing step S905:

[0243] Step S9056: When the phase of the power grid is in the phase interval , determine whether the polarity of the voltage impact signal is positive. If it is positive, execute step S9057; if it is negative, execute step S9059.

[0244] During the specific execution of step S9056, when it is determined that the phase of the power grid is in the phase interval , if the polarity of the voltage impact signal is positive, it indicates that the actual closing moment of the controllable switch occurs on the right side of the theoretical position . The specified phase of the previously determined issued closing instruction should be shifted to the left, that is, reduced by one phase adjustment step to compensate for the generated offset, that is, execute step S9057.

[0245] If the polarity of the voltage impact signal is negative, it indicates that the actual closing moment of the controllable switch occurs on the left side of the theoretical position . The specified phase of the previously determined issued closing instruction should be shifted to the right, that is, increased by one phase adjustment step to compensate for the generated offset, and then execute step S9059.

[0246] Step S9057: Determine the phase adjustment step.

[0247] During the specific execution of step S9057, generate a phase adjustment step according to formula (3).

[0248] Step S9058: Use the difference between the specified phase of the previously determined issued closing instruction and the phase adjustment step as the specified trigger value for the next issued closing instruction.

[0249] During the specific execution of step S9058, obtain the difference between the specified phase of the previously determined issued closing instruction and the phase adjustment step ( ), and use this difference ( ) as the specified trigger value for the next issued closing instruction.

[0250] Step S9059: Determine the phase adjustment step.

[0251] During the specific execution of step S9059, a phase adjustment step size is generated according to formula (3). .

[0252] Step S9050: Use the sum of the specified phase of the previously determined closing command and the phase adjustment step size as the specified trigger value for the next issued closing command.

[0253] During the specific execution of step S9050, obtain the specified phase of the previously determined closing command and the phase adjustment step size . The sum value ( ) is used as the specified trigger value for the next issued closing command. ).

[0254] For example, assume that the issuing time of the closing command corresponding to the specified phase is at the time of the phase of the power grid. , at this time, a voltage impulse signal is generated at the input end of the controllable switch, and the power grid voltage changes to positive growth. At this time, the phase interval where the phase of the power grid is located is . According to the polarity judgment of the voltage impulse signal, the following adjustment logic is obtained:

[0255] When ,

[0256] (1) The polarity of the voltage impulse signal is positive, and the specified trigger value (action time) for the next issued closing command is: ;

[0257] (2) The polarity of the voltage impulse signal is negative, and the specified trigger value (action time) for the next issued closing command is: .

[0258] Based on the controllable switch control method disclosed in the embodiments of the present application, whether an impulse signal occurs at the input end or the output end of the controllable switch, the above method can be used to control the controllable switch.

[0259] Based on the controllable switch control method disclosed in the embodiments of the present application, by detecting the polarity of the voltage impulse signal each time the controllable switch is closed, and according to the phase interval where the phase of the above-mentioned power grid is located, as well as the adjustment logic of the specified trigger value (specified trigger phase) based on the polarity of the voltage impulse signal, the time of the next issued closing command is gradually fine-tuned, so that the voltage impulse becomes smaller and smaller, and finally the purpose of no impulse is achieved, making the controllable switch close as close as possible to the true voltage zero crossing, reducing the impulse and improving the relay life.

[0260] It should be noted that the control of the above controllable switch adjusts the specified trigger value by means of the phase of the power grid and the polarity of the voltage impact signal. If the specified trigger value is the specified voltage, the voltage of the power grid can also be directly collected for judgment. Specifically, as Figure 11 shown, it is a schematic flowchart of another control method for a controllable switch disclosed in an embodiment of the present application. It should be noted that the following content related to the specified voltage can all be applied to Figure 3 the access method of the disclosed electrical equipment. The control method of this controllable switch mainly includes the following steps:

[0261] Step S1101: When the controllable switch is in the off state, obtain the voltage of the power grid connected to the output end of the controllable switch.

[0262] Step S1102: When the voltage of the power grid reaches the specified voltage for the previously determined issued closing instruction, control the controllable switch to close.

[0263] The specific execution processes and principles of the above Step S1101 and Step S1102 are similar to Figure 4 the shown Step S401 and Step S402, which can be referred to and will not be elaborated here.

[0264] Step S1103: During the process of the controllable switch changing from the off state to the on state, detect whether a voltage impact signal is generated at the input end or the output end of the controllable switch. If a voltage impact signal is generated, execute S1104; if no voltage impact signal is generated, execute S1109.

[0265] The specific execution process and principle of the above Step S1103 are the same as Figure 5 the shown Step S503, which can be referred to and will not be elaborated here.

[0266] Step S1104: Determine the polarity of the voltage impact signal. If the polarity of the voltage impact signal is positive, execute Step S1105; if the polarity of the voltage impact signal is negative, then execute Step S1107.

[0267] In Step S1104, the polarity of the voltage impact signal is positive or negative. By determining the positive polarity or negative polarity of the voltage impact signal, it can be determined on which side of the zero crossing the voltage impact occurs when the controllable switch closes.

[0268] During the specific execution of Step S1104, if the polarity of the voltage impact signal is positive, it means that the actual closing moment of the controllable switch occurs on the left side of the theoretical position and the specified voltage for the previously determined issued closing instruction should be shifted to the right, that is, reduced by one voltage adjustment step to compensate for the generated offset, that is, execute Step S1105 to Step S1106.

[0269] If the polarity of the voltage impact signal is negative, it indicates that the actual closing moment of the controllable switch occurs on the right side of the theoretical position, and the specified voltage u0 for the previously determined issued closing command should be shifted to the left, that is, a voltage adjustment step is increased. to compensate for the generated offset, that is, steps S1107 to S1108 are executed.

[0270] Step S1105: Determine the voltage adjustment step.

[0271] In the specific process of executing step S1105: Obtain the voltage impact value of the voltage impact signal, and determine the voltage adjustment step according to the voltage impact value.

[0272] For example, when the voltage impact value is large, the voltage adjustment step will be larger, and when the voltage impact value is small, the voltage adjustment step will be smaller, gradually approaching the true zero crossing point.

[0273] Specifically, the voltage adjustment step is positively correlated with the voltage impact value. Specifically, as shown in formula (4).

[0274] (4)

[0275] Among them, is the phase adjustment step, is the voltage impact value, k≥1.

[0276] Step S1106: Use the difference between the previously determined specified voltage for the issued closing command and the voltage adjustment step as the specified trigger value for the next issued closing command.

[0277] In the specific process of executing step S1106, obtain the difference between the previously determined specified voltage u0 for the issued closing command and the voltage adjustment step () and use this difference ( ()) as the specified trigger value for the next issued closing command.

[0278] Step S1107: Determine the voltage adjustment step.

[0279] In the specific process of executing step S1107, generate a voltage adjustment step according to formula (4) .

[0280] Step S1108: Use the sum of the previously determined specified voltage for the issued closing command and the voltage adjustment step as the specified trigger value for the next issued closing command.

[0281] ​During the specific execution of step S1106, the sum of the specified voltage u0 of the previously determined closing command and the voltage adjustment step is obtained ), and this sum value ( ) is used as the specified trigger value for the next closing command. ) is used as the specified trigger value for the next closing command.

[0282] Step S1109: Continue to use the specified trigger value of the previously determined closing command as the specified trigger value for the next closing command.

[0283] Taking Figure 12 as an example, assume that the issuing time of the closing command corresponding to the specified voltage is the u0 moment. At this time, a voltage impact signal is generated at the input end of the controllable switch. According to the polarity judgment of the voltage impact signal, the following adjustment logic is obtained:

[0284] (1) If the polarity of the voltage impact signal is positive, the specified trigger value (action time) for the next closing command is: ;

[0285] (2) If the polarity of the voltage impact signal is negative, the specified trigger value (action time) for the next closing command is: .

[0286] Based on the control method of the controllable switch disclosed in the above embodiments of the present application, whether an impact signal occurs at the input end or the output end of the controllable switch, the controllable switch can be controlled in the above manner.

[0287] Based on the control method of the controllable switch disclosed in the above embodiments of the present application, by detecting the polarity of the voltage impact signal each time the controllable switch closes, and according to the adjustment logic of the specified trigger value (specified voltage) based on the specified voltage and the polarity of the voltage impact signal, the time of the next closing command is gradually fine-tuned, so that the voltage impact becomes smaller and smaller, and finally the purpose of no impact is achieved, making the controllable switch close as close as possible to the true voltage zero crossing, reducing the impact and improving the relay life.

[0288] Based on the control method of the controllable switch disclosed in the above embodiments of the present application, the embodiments of the present application also correspondingly disclose a control circuit of the controllable switch, as Figure 13 shown. The control circuit of the controllable switch includes: a controllable switch 130, a detection circuit (not shown in the figure), and a controller 131.

[0289] The input end of the controllable switch 130 is connected to a converter or a load (shown in words in the figure). The output end of the controllable switch 130 is connected to an input end of a power supply 132. The other input end of the power supply 132 is connected to an electrical device 133, and a loop is formed by the electrical device 133, the controllable switch 130, and the power supply 132.

[0290] Among them, the power supply 132 can be Figure 2 the power grid 21 shown in

[0291] In an embodiment of the present application, there is one or more controllable switches 130 connected in series in the loop.

[0292] In an embodiment of the present application, the controllable switch 130 includes a relay or a circuit breaker.

[0293] In an embodiment of the present application, the controllable switch 130 and the controller 131 are the controllable switch and the controller in a power converter connected to the power grid.

[0294] Optionally, the power converter is an inverter, specifically a grid-connected inverter.

[0295] The detection circuit is arranged at the input end or the output end of the controllable switch 130, and is used for detecting the impact signal generated at the input end or the output end of the controllable switch 130 during the process of the controllable switch 130 changing from the off state to the on state. That is, obtaining the impact signal generated by the power supply 132 on the electrical device 133 when the controllable switch is closed.

[0296] The input end of the controller 131 is connected to the output end of the detection circuit, and the control end of the controller 131 is connected to the movable end of the controllable switch 130. The controller is used to execute any one of the controllable switch control methods disclosed in the embodiments of the present application.

[0297] In an embodiment of the present invention, the detection circuit includes a voltage detection circuit or a current detection circuit.

[0298] Optionally, the voltage detection circuit includes a voltage sensor, and the current detection circuit includes a current sensor.

[0299] The voltage detection circuit is used to detect the voltage impact signal at the input end and / or the output end of the controllable switch 130.

[0300] Such as Figure 14 shown, is another control circuit of a controllable switch disclosed in the embodiments of the present application. In the control circuit of the controllable switch, a voltage detection circuit 134 is arranged at the output end of the detection controllable switch 130, and is used to detect the voltage impact signal at the output end of the controllable switch 130.

[0301] The current detection circuit is arranged at the input end or the output end of the controllable switch 130, and is used to detect the current impact signal at the input end or the output end of the controllable switch 130.

[0302] Based on the control circuit of the controllable switch provided in the embodiments of the present application, during each process in which the controllable switch changes from the off state to the on state, the specified trigger value of the next issued closing instruction is continuously corrected by using the detected impact signal at both ends of the controllable switch, so that each time the controllable switch closes, it is as close as possible to the true voltage zero crossing, reducing the impact and improving the service life of the controllable switch.

[0303] Based on the access circuit of the electrical equipment disclosed in the embodiments of the present application, the present application also discloses a power converter, which includes the above Figure 13 and Figure 14 control circuit of the disclosed control switch.

[0304] The present application also discloses a new energy system, which includes the power converter disclosed in the present application.

[0305] In this specification, the various embodiments are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For the relevant parts, reference can be made to the description in the method part.

[0306] Those skilled in the art can further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in this article can be implemented by electronic hardware, computer software, or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been generally described according to their functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0307] In the present application, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, the element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including the said element.

[0308] The foregoing description of the disclosed embodiments enables those skilled in the art to practice or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for a controllable switch, characterized in that: Applicable to an electrical device, the electrical device comprising a controllable switch, the method comprising: When the controllable switch is in an off state, obtaining an electrical parameter of an output end of the controllable switch; When the electrical parameter reaches a specified trigger value, controlling the controllable switch to close; The designated trigger value is obtained by correcting a trigger value used to control the closing of the controllable switch in the historical control closing process based on an impulse signal generated in the historical control closing process of the controllable switch.

2. The method according to claim 1, characterized in that The electrical parameter includes a phase, and the specified trigger value includes a specified phase; The obtaining of the electrical parameters of the output end of the controllable switch includes: Acquiring a voltage at an output end of the controllable switch; Calculating the voltage at the output end of the controllable switch based on a phase-locked loop to obtain the phase of the output end of the controllable switch; Accordingly, when the electrical parameter reaches a specified trigger value, controlling the controllable switch to close includes: When the phase of the output end of the controllable switch reaches a specified phase, a closing instruction is sent to the controllable switch to control the controllable switch to close.

3. The method according to claim 1, characterized in that The electrical parameter includes voltage, and the specified trigger value includes a specified voltage; The obtaining of the electrical parameters of the output end of the control switch includes: Acquiring a voltage at an output end of the controllable switch; Accordingly, when the electrical parameter reaches a specified trigger value, controlling the controllable switch comprises: When the voltage at the output end of the controllable switch reaches a specified voltage, a closing instruction is sent to the controllable switch to control the controllable switch to close.

4. The method according to claim 1, characterized in that The process of controlling the controllable switch to close includes: Detecting whether a voltage surge signal is generated on the controllable switch side when the controllable switch is closed; If a voltage surge signal is generated, the current designated trigger value is corrected based on the voltage surge signal to obtain the designated trigger value for controlling the controllable switch to close next time; If no voltage surge signal is generated, continue to use the current designated trigger value as the designated trigger value for controlling the controllable switch to close next time; Alternatively, detecting whether a current surge signal is generated on the controllable switch side when the controllable switch is closed; If a current impact signal is generated, the current designated trigger value is corrected based on the current impact signal to obtain the designated trigger value for controlling the controllable switch to close next time; If no current impact signal is generated, the current designated trigger value continues to be used as the designated trigger value for controlling the controllable switch to close next time.

5. The method according to claim 4, characterized in that If the designated trigger value includes a designated phase, the current designated trigger value is corrected based on the voltage surge signal to obtain the designated trigger value for controlling the controllable switch to close next time, including: Determining the generation time of the voltage impulse signal; Determining the sending time of the closing instruction according to the specified phase this time; Calculating the actual closing time of the controllable switch according to the sending time of the closing instruction and the generating time of the voltage surge signal; The phase change value is calculated according to the actual closing time of the controllable switch and the power grid cycle; The phase change value is used to correct the current designated phase, so as to obtain a designated trigger value for controlling the controllable switch to close next time.

6. The method according to claim 4, characterized in that If the designated trigger value includes a designated phase, the current designated trigger value is corrected based on the voltage surge signal to obtain the designated trigger value for controlling the controllable switch to close next time, including: Determining the polarity of the voltage impulse signal and the phase interval in which the phase of the output end of the controllable switch is located; According to the polarity of the voltage impulse signal and the phase interval, the current designated phase is corrected using the determined phase adjustment step to obtain a designated trigger value for controlling the controllable switch to close next time.

7. The method according to claim 6, characterized in that According to the polarity of the voltage impulse signal and the phase interval, the current designated phase is corrected using the determined phase adjustment step to obtain a designated trigger value for controlling the controllable switch to close next time, including: When the phase of the controllable switch output terminal is in the phase interval , and when the polarity of the voltage impulse signal is positive, obtaining a determined phase adjustment step; The sum of the current designated phase and the phase adjustment step is used as the designated trigger value for controlling the controllable switch to close next time; When the phase of the controllable switch output terminal is in the phase interval , and when the polarity of the voltage impulse signal is negative, obtaining a determined phase adjustment step; The difference between the current designated phase and the phase adjustment step is used as the designated trigger value for controlling the controllable switch to close next time.

8. The method according to claim 6, characterized in that According to the polarity of the voltage impulse signal and the phase interval, the current designated phase is corrected using the determined phase adjustment step to obtain a designated trigger value for controlling the controllable switch to close next time, including: When the phase of the controllable switch output terminal is in the phase interval or , and when the polarity of the voltage impulse signal is positive, obtaining a determined phase adjustment step; The difference between the current designated phase and the phase adjustment step is used as the designated trigger value for controlling the controllable switch to close next time; When the phase of the controllable switch output terminal is in the phase interval or , and when the polarity of the voltage impulse signal is negative, obtaining a determined phase adjustment step; The sum of the current designated phase and the phase adjustment step is used as the designated trigger value for controlling the controllable switch to close next time.

9. The method according to any one of claims 6 to 8, characterized in that The process of determining the phase adjustment step size includes: A voltage impact value of the voltage impact signal is acquired, and a phase adjustment step is determined according to the voltage impact value, wherein the phase adjustment step is positively correlated with the voltage impact value.

10. The method according to claim 4, characterized in that If the designated trigger value includes a designated voltage, the current designated trigger value is corrected based on the voltage surge signal to obtain the designated trigger value for controlling the controllable switch to close next time, including: Determining the polarity of the voltage impulse signal; If the polarity of the voltage impulse signal is positive, the difference between the current specified voltage and the determined voltage adjustment step is used as the specified trigger value for controlling the controllable switch to close next time; If the polarity of the voltage impulse signal is negative, the sum of the current designated voltage and the determined voltage adjustment step is used as the designated trigger value for controlling the controllable switch to close next time.

11. The method according to claim 10, characterized in that The process of determining the voltage adjustment step size includes: A voltage impact value of the voltage impact signal is acquired, and a voltage adjustment step length is determined according to the voltage impact value, wherein the voltage adjustment step length is positively correlated with the voltage impact value.

12. The method according to claim 4, characterized in that If the designated trigger value includes a designated phase, the current designated trigger value is corrected based on the current impulse signal to obtain the designated trigger value for controlling the controllable switch to close next time, including: Determining the generation time of the current impulse signal; Determining the sending time of the closing instruction according to the specified phase this time; Calculating the actual closing time of the controllable switch according to the sending time of the closing instruction and the generating time of the current impulse signal; The phase change value is calculated according to the actual closing time of the controllable switch and the power grid cycle; The phase change value is used to correct the current designated phase, and obtain a designated trigger value for controlling the controllable switch to close next time.

13. The method according to any one of claims 5 to 8 or 12, characterized in that Also includes: In the process of controlling the controllable switch to close multiple times, if the amplitude of the phase change value exceeds the preset amplitude for a preset number of times, a switch fault alarm is executed.

14. The method according to any one of claims 1 to 8 or 12, characterized in that If the specified trigger value includes a specified phase, it also includes: The specified trigger value for sending the closing instruction for the first time is set according to the theoretical closing time of the controllable switch.

15. A control circuit for a controllable switch, characterized in that: The control circuit comprises: a controllable switch, a detection circuit and a controller; The input end of the controllable switch is connected to the electrical device, the output end of the controllable switch is connected to one input end of a power supply, and the other input end of the power supply is connected to the electrical device, so as to obtain a loop formed by the electrical device, the controllable switch and the power supply; The detection circuit is arranged at the input end or the output end of the controllable switch, and is used to obtain the impact signal generated during the closing process of the controllable switch; The controller input end is connected to the output end of the detection circuit, the controller control end is connected to the active end of the controllable switch, and the controller is used to execute the control method of the controllable switch according to any one of claims 1 to 14.

16. The control circuit of the controllable switch according to claim 15, characterized in that: The detection circuit includes a voltage detection circuit or a current detection circuit.

17. The control circuit of the controllable switch according to claim 15, characterized in that: The loop has one or more controllable switches connected in series, and the controllable switches include relays or circuit breakers.

18. A power converter, characterized in that: The power converter comprises a control circuit for a controllable switch according to any one of claims 15 to 17.

19. A new energy system, characterized in that: The new energy system includes the power converter described in claim 18.

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