Relay closing control method and three-phase energy meter

Abstract

This application relates to the field of relays and discloses a relay closing control method and a three-phase energy meter. The method includes: acquiring the three-phase voltage values ​​of the relay, wherein the three-phase voltage values ​​include the first-phase voltage value of the first voltage phase, the second-phase voltage value of the second voltage phase, and the third-phase voltage value of the third voltage phase on the three-phase circuit connected to the relay; selecting a detection phase to determine the voltage zero-crossing detection phase based on the first-phase voltage value, the second-phase voltage value, the third-phase voltage value, and a preset voltage; and controlling the relay to close based on the voltage zero-crossing detection phase, so as to realize the relay closing at the voltage zero-crossing point. This application improves the service life of the relay.

Description

Technical Field

[0001] This application relates to the field of relays, and more particularly to a relay closing control method and a three-phase energy meter. Background Technology

[0002] With the rapid development of relays, users have placed higher demands on the closing control methods of relays.

[0003] Traditional relay closing control directly and in real-time closes the relay upon receiving a closing request, essentially performing random closing based on that request. This method has certain drawbacks. Random closing might occur at maximum voltage (where the capacitive load environment creates a large inrush current at the relay contacts), potentially damaging the relay contacts and thus shortening the relay's lifespan. Summary of the Invention

[0004] The main purpose of this application is to propose a relay closing control method and a three-phase energy meter, aiming to solve the technical problem of the short service life of relays.

[0005] To achieve the above objectives, this application provides a relay closing control method, which includes the following steps:

[0006] Obtain the three-phase voltage values ​​of the relay, wherein the three-phase voltage values ​​include the first phase voltage value of the first voltage phase, the second phase voltage value of the second voltage phase, and the third phase voltage value of the third voltage phase in the three-phase circuit connected to the relay;

[0007] The voltage zero-crossing detection phase is determined by selecting the detection phase based on the first phase voltage value, the second phase voltage value, the third phase voltage value, and the preset voltage. The relay is then controlled to close based on the voltage zero-crossing detection phase, so that the relay closes at the voltage zero-crossing point.

[0008] In one embodiment, the step of selecting the detection phase and determining the zero-crossing detection phase based on the first phase voltage value, the second phase voltage value, the third phase voltage value, and a preset voltage includes:

[0009] Determine the maximum voltage value among the first phase voltage value, the second phase voltage value, and the third phase voltage value;

[0010] If the voltage phase corresponding to the maximum voltage value is a preset voltage selection detection phase, then the selected detection phase is determined as the voltage zero-crossing detection phase.

[0011] If the voltage phase corresponding to the maximum voltage value is not the preset voltage selection detection phase, determine the target voltage value of the selected detection phase among the first phase voltage value, the second phase voltage value, and the third phase voltage value, and determine the voltage zero-crossing detection phase based on the maximum voltage value and the target voltage value.

[0012] In one embodiment, the step of determining the voltage zero-crossing detection phase based on the maximum voltage value and the target voltage value includes:

[0013] Determine the voltage difference between the maximum voltage value and the target voltage value;

[0014] If the voltage difference is greater than a preset difference threshold, the voltage phase corresponding to the maximum voltage value is taken as the voltage zero-crossing detection phase.

[0015] If the voltage difference is less than or equal to a preset difference threshold, the selected detection phase is used as the voltage zero-crossing detection phase.

[0016] In one embodiment, the step of controlling the relay to close based on the voltage zero-crossing detection phase includes:

[0017] Obtain the real-time voltage value of the voltage zero-crossing detection phase;

[0018] When the real-time voltage value is a preset zero-crossing voltage value, the relay is controlled to close.

[0019] In one embodiment, after the step of controlling the relay to close based on the voltage zero-crossing detection phase, the method includes:

[0020] Determine the closing action duration corresponding to the voltage zero-crossing detection;

[0021] The closing interval duration of the voltage zero-crossing detection phase is determined based on the closing action duration and the preset voltage cycle duration.

[0022] In one embodiment, after the step of obtaining the three-phase voltage value of the relay, the method includes:

[0023] If at least one of the first phase voltage value, the second phase voltage value, and the third phase voltage value is greater than a preset voltage threshold, the step of selecting a detection phase and determining the zero-crossing detection phase based on the first phase voltage value, the second phase voltage value, the third phase voltage value, and the preset voltage is executed.

[0024] In one embodiment, after the step of obtaining the three-phase voltage value of the relay, the method further includes:

[0025] When the voltage values ​​of the first phase, the second phase, and the third phase are all less than or equal to a preset voltage threshold, the relay is controlled to close.

[0026] In one embodiment, the relay closing control method further includes:

[0027] After receiving a closing control command each time, the first voltage phase, the second voltage phase, and the third voltage phase are selected as the preset voltage detection phases in a polling manner.

[0028] In one embodiment, after the step of controlling the relay to close based on the voltage zero-crossing detection phase, the method includes:

[0029] If the voltage zero-crossing detection phase is a preset voltage selection detection phase, determine the next preset voltage selection detection phase, and perform the step of obtaining the three-phase voltage value of the relay based on the next preset voltage selection detection phase;

[0030] If the voltage zero-crossing detection phase is not the preset voltage selection detection phase, determine the next preset voltage selection detection phase, and perform the step of obtaining the three-phase voltage value of the relay based on the next preset voltage selection detection phase, or perform the step of obtaining the three-phase voltage value of the relay.

[0031] This application also provides a three-phase energy meter, the three-phase energy meter comprising:

[0032] The relay is connected to the power grid;

[0033] A closing controller, wherein the closing controller is connected to the control terminal of the relay;

[0034] The closing controller is also used to perform the steps of the relay closing control method described above.

[0035] This application provides a method for controlling the closing of a relay. The method involves acquiring the three-phase voltage values ​​of the relay, wherein the three-phase voltage values ​​include the first-phase voltage value of the first voltage phase, the second-phase voltage value of the second voltage phase, and the third-phase voltage value of the third voltage phase in the three-phase circuit connected to the relay; selecting a detection phase based on the first-phase voltage value, the second-phase voltage value, the third-phase voltage value, and a preset voltage to determine the voltage zero-crossing detection phase; and controlling the relay to close based on the voltage zero-crossing detection phase to achieve the relay closing at the voltage zero-crossing point.

[0036] By selecting the detection phase from the first, second, and third phase voltage values ​​and a preset voltage in the three-phase circuit connected to the relay, a zero-crossing detection phase is determined. The relay is then controlled to close when the voltage of this detection phase crosses zero. This avoids the problem in existing technologies where random closing might occur at maximum voltage (resulting in a large inrush current at the relay contacts due to the capacitive load environment), which could damage the relay contacts. By controlling the relay to close at the zero-crossing detection phase, the phenomenon of closing at maximum voltage is avoided, thus extending the relay's lifespan. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the closing controller structure of a relay in the hardware operating environment of an embodiment of this application.

[0039] Figure 2 This is a schematic flowchart of a relay closing control method according to an embodiment of this application;

[0040] Figure 3 This is a schematic diagram of a control flow for a relay closing control method according to an embodiment of this application;

[0041] Figure 4 This is a schematic diagram of a module of a three-phase energy meter according to an embodiment of this application;

[0042] Figure 5 This is a schematic diagram of a closing controller module according to an embodiment of this application.

[0043] Explanation of icon numbers:

[0044] 0001, Communication bus; 0002, Acquisition interface; 0003, Processor; 0004, Processing interface; 0005, Memory; 100, Three-phase energy meter; 10, Relay; 20, Closing controller; 200, Power grid.

[0045] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0047] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0048] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0049] Reference Figure 1 , Figure 1 This is a schematic diagram of the closing controller structure of the relay in the hardware operating environment involved in the embodiments of this application.

[0050] like Figure 1 As shown, the closing controller of this relay may include: a processor 0003, such as a central processing unit (CPU), a communication bus 0001, an acquisition interface 0002, a processing interface 0004, and a memory 0005. The communication bus 0001 is used to realize communication between these components. The acquisition interface 0002 may include an information acquisition device or acquisition unit such as a computer; optionally, the acquisition interface 0002 may also include a standard wired interface or a wireless interface. The processing interface 0004 may optionally include a standard wired interface or a wireless interface. The memory 0005 may be a high-speed random access memory (RAM) or a stable non-volatile memory (NVM), such as a disk storage device. Optionally, the memory 0005 may also be a storage device independent of the aforementioned processor 0003.

[0051] Those skilled in the art will understand that Figure 1 The structure shown does not constitute a limitation on the closing controller of the relay, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0052] like Figure 1 As shown, the memory 0005, which is a computer storage medium, may include an acquisition interface module, a processing interface module, and a relay closing control program.

[0053] exist Figure 1 In the relay closing controller shown, the communication bus 0001 is mainly used to realize the connection and communication between components; the acquisition interface 0002 is mainly used to connect to the backend server and communicate data with the backend server; the processing interface 0004 is mainly used to connect to the deployment end (user end) and communicate data with the deployment end; the processor 0003 and the memory 0005 in the relay closing controller of this application can be set in the relay closing controller. The relay closing controller calls the relay closing control program stored in the memory 0005 through the processor 0003 and executes the relay closing control method provided in the embodiment of this application.

[0054] Based on the above hardware structure, an embodiment of the relay closing control method of this application is proposed.

[0055] In one embodiment of this application, as Figure 2 As shown, Figure 2 This is a flowchart illustrating a relay closing control method according to an embodiment of this application. The relay closing control method includes:

[0056] Step S10: Obtain the three-phase voltage values ​​of the relay, wherein the three-phase voltage values ​​include the first phase voltage value of the first voltage phase, the second phase voltage value of the second voltage phase, and the third phase voltage value of the third voltage phase on the three-phase circuit connected to the relay.

[0057] For example, when a relay is closed, it is equivalent to a capacitive load (i.e., the relay can be roughly equivalent to a capacitor). In this capacitive load environment, at the instant the relay closes, because the voltage across the capacitor cannot change abruptly, a very large instantaneous inrush current is generated. This instantaneous inrush current can be several times the current in the closed state. The instantaneous inrush current satisfies I = C * dV / dt, where C is the equivalent capacitance value and dV / dt is the rate of voltage change. If the energy generated by this instantaneous inrush current and the relay contact resistance is large enough, it may damage or burn out the relay contacts. Therefore, the larger the instantaneous inrush current generated at the moment the relay closes, the greater the energy generated by the instantaneous inrush current and the relay contact resistance, the greater the impact on the contacts, and the higher the degree of damage to the contacts. If the closing is controlled at the highest point of the power grid connected to the relay, there will be a point where dV / dt is at its maximum, meaning the energy generated by the instantaneous inrush current and the relay contact resistance is at its maximum, thus causing damage to the relay contacts.

[0058] In this embodiment, the relay can be a three-phase relay connected to the power grid, or a three-phase relay connected to a device that transmits or generates electrical energy. The three-phase relay can be a three-phase magnetic latching relay, a three-phase circuit breaker, or any other switch associated with three-phase AC power. When relay closing control is required, the closing control is performed by acquiring the three-phase voltage values ​​of the relay (this can be executed based on closing control requirements or other situations, such as directly training and recording the time points when the relay can perform closing control and storing them for later use). Based on the three-phase voltage values ​​of the relay and a preset voltage selection detection phase, a zero-crossing detection phase is determined. That is, based on the three-phase voltage values, it is determined whether to use a user-defined preset voltage selection detection phase as the zero-crossing detection phase or another voltage phase. After zero-crossing detection of the zero-crossing detection phase, the relay is closed to avoid damage caused by excessive voltage during closing, thereby improving the relay's service life. The three-phase voltage values ​​include the voltage values ​​at the three-phase AC power source, such as the power grid connected to the relay; that is, the three voltage values ​​on the three voltage phases. They can also be other locations that generate and transmit three-phase AC power, which are not limited here. For example, the first voltage phase refers to the first voltage phase on the power grid, such as phase A on the power grid, and the first phase voltage value refers to the voltage value on the first voltage phase. The second voltage phase refers to the second voltage phase on the power grid, such as phase B on the power grid, and the second phase voltage value refers to the voltage value on the second voltage phase. The third voltage phase refers to the third voltage phase on the power grid, such as phase C on the power grid, and the third phase voltage value refers to the voltage value on the third voltage phase. The preset voltage selection detection phase refers to the voltage phase selected by the user as the voltage phase for detecting zero-crossing voltage. The zero-crossing voltage detection phase refers to the voltage phase that needs to be detected based on the three-phase voltage; this voltage phase can be one of the three voltage phases, or it can be directly the preset voltage selection detection phase.

[0059] Step S20: Select the detection phase based on the first phase voltage value, the second phase voltage value, the third phase voltage value and the preset voltage to determine the voltage zero-crossing detection phase, and control the relay to close according to the voltage zero-crossing detection phase so as to realize the relay closing at the voltage zero-crossing point.

[0060] In this embodiment, after determining the voltage zero-crossing detection phase based on the first phase voltage value, the second phase voltage value, the third phase voltage value, and the preset voltage selection detection phase, the voltage of that phase is detected for zero crossing in real time. When the voltage zero-crossing detection phase is detected to be zero-crossing, the relay is controlled to close, thus achieving relay closing at the voltage zero-crossing point. Because when one phase voltage in the three-phase voltage crosses zero, the voltages of the other two phases are approximately 0.8, the voltages of the other two phases will not be at their maximum values, thereby reducing the damage to the relay contacts caused by the high voltage of the other two phases. Furthermore, by controlling the closing of a single phase through zero-crossing detection, this application ensures that, under capacitive load conditions, the three contacts of the three-phase relay bear the instantaneous inrush current of the relay closing on an average basis (because each of the three phases has a voltage value of approximately 0.8, this greatly balances the wear and tear on the three relay contacts), and any contact of the three-phase relay can avoid closing at the highest voltage point, effectively improving the service life of the relay.

[0061] For example, the following experiments were conducted to control random closing and the zero-crossing detection closing of this application. An effect test was performed using an energy meter from the same batch with a built-in 100A current-rated magnetic latching relay. The test conditions were: 253V, 100A, 0.8C capacitive load opening and closing (ensuring no power was applied during opening, and closing was performed during the experiment). The test determined how many opening and closing cycles would damage the magnetic latching relay. Five three-phase energy meters with identical performance were randomly selected for both the random closing control method and the zero-crossing detection control closing method of this application. A 100A, 0.8C relay life test was conducted. Using the random closing control method to control the opening and closing of the three-phase relays, the average number of opening and closing cycles when the five energy meters failed was 12,542 (12,553, 13,049, 14,263, 11,862, and 10,984 respectively). Using the zero-crossing detection control closing method of this application to control the opening and closing of the three-phase relays, the average number of opening and closing cycles when the five energy meters failed was 15,118 (15,389, 15,516, 14,897, 14,762, and 15,028 respectively). Compared with the two closing control methods, the zero-crossing detection control closing method of this application can effectively improve the service life of the relay by about 20%, and the service life consistency of the relay is better (that is, the consumption of the three contacts is consistent, and there will be no one contact being damaged a long time in advance. Generally, the number of times the three contacts fail is not much different).

[0062] This embodiment provides a relay closing control method. It acquires the three-phase voltage values ​​of the relay, including the first-phase voltage value of the first voltage phase, the second-phase voltage value of the second voltage phase, and the third-phase voltage value of the third voltage phase in the three-phase circuit connected to the relay. Based on the first-phase voltage value, the second-phase voltage value, the third-phase voltage value, and a preset voltage selection detection phase, a voltage zero-crossing detection phase is determined. The relay is then closed based on the voltage zero-crossing detection phase, thereby achieving relay closing at the voltage zero-crossing point. By selecting the first-phase voltage value, the second-phase voltage value, the third-phase voltage value, and the preset voltage selection detection phase in the three-phase circuit connected to the relay, the voltage zero-crossing detection phase is used to determine the voltage zero-crossing detection phase, and the relay is closed when the voltage of the voltage zero-crossing detection phase crosses zero. This avoids the problem in existing technologies where random closing might occur at the maximum voltage (where the capacitive load environment causes a large inrush current to form at the relay contacts), which could damage the relay contacts. By controlling the relay to close when the voltage of the voltage-zero detection phase crosses zero, the phenomenon of closing at the maximum voltage is avoided, thereby improving the service life of the relay.

[0063] In one embodiment, a second embodiment of the relay-based closing control method is proposed, which further includes the step of selecting a detection phase and determining the zero-crossing detection phase based on the first phase voltage value, the second phase voltage value, the third phase voltage value, and a preset voltage.

[0064] Step S21: Determine the maximum voltage value among the first phase voltage value, the second phase voltage value, and the third phase voltage value;

[0065] Step S22: If the voltage phase corresponding to the maximum voltage value is the preset voltage selection detection phase, determine the selected detection phase as the voltage zero-crossing detection phase;

[0066] Step S23: If the voltage phase corresponding to the maximum voltage value is not the preset voltage selection detection phase, determine the target voltage value corresponding to the selected detection phase among the first phase voltage value, the second phase voltage value, and the third phase voltage value, and determine the voltage zero crossing detection phase based on the maximum voltage value and the target voltage value.

[0067] In this embodiment, when it is determined that voltage zero crossing detection is required, the largest voltage value among the first-phase, second-phase, and third-phase voltage values ​​is selected. That is, the largest voltage value among the three is chosen as the maximum voltage value, and the phase corresponding to this maximum voltage value is selected as the voltage zero crossing detection phase. In other words, if the phase corresponding to the largest voltage value is a preset voltage selection phase, then this phase is selected as the voltage zero crossing detection phase. Conversely, if the phase corresponding to the largest voltage value is not a preset voltage selection phase, a target voltage value corresponding to the selected phase among the first-phase, second-phase, and third-phase voltage values ​​is determined. The voltage zero crossing detection phase is then determined based on the maximum voltage value and the target voltage value. The target voltage value refers to the voltage value corresponding to the selected phase, which is one of the first-phase, second-phase, and third-phase voltage values. This allows the zero-crossing detection phase to be determined based on the maximum and target voltage values. After zero-crossing detection is performed on the zero-crossing detection phase, the relay can be closed, thus avoiding damage to the relay contacts of a certain phase caused by a high voltage, and ensuring the service life of the relay contacts of that phase.

[0068] Furthermore, the step of determining the voltage zero-crossing detection phase based on the maximum voltage value and the target voltage value includes:

[0069] Step S231: Determine the voltage difference between the maximum voltage value and the target voltage value;

[0070] Step S232: If the voltage difference is greater than a preset difference threshold, the voltage phase corresponding to the maximum voltage value is taken as the voltage zero-crossing detection phase.

[0071] Step S233: If the voltage difference is less than or equal to a preset difference threshold, the detection phase will be selected as the voltage zero-crossing detection phase.

[0072] In this embodiment, when determining the voltage zero-crossing detection phase based on the maximum voltage value and the target voltage value, the voltage difference between the maximum voltage value and the target voltage value is determined. If the voltage difference is greater than a preset difference threshold, the voltage phase corresponding to the maximum voltage value is selected as the voltage zero-crossing detection phase. That is, the voltage phase corresponding to the maximum voltage value is prioritized for zero-crossing detection to avoid damage to the relay contacts due to excessive voltage in that phase. Conversely, if the voltage difference is less than or equal to the preset difference threshold, a detection phase is selected as the voltage zero-crossing detection phase. The advantage of setting a preset difference threshold here is to avoid identification errors caused by fluctuations in the acquired voltage, thereby ensuring the accuracy of determining the maximum voltage value and thus ensuring the accuracy of determining the voltage zero-crossing detection phase and subsequent closing control.

[0073] In another embodiment, refer to Figure 3 , Figure 3 This is a schematic diagram of a control flow for a relay closing control method according to an embodiment of this application. The method detects whether the ratio of the voltage values ​​of other phases to the voltage value of a designated zero-crossing detection phase (selected detection phase) is greater than a certain specified percentage (e.g., the specified percentage can be 120%, exceeding the larger value by 20%, which can be adjusted appropriately according to application requirements). If the ratio is greater than the specified percentage, the voltage phase corresponding to the maximum voltage value is used as the zero-crossing detection phase, and a phase change record is made, i.e., it is recorded that this phase has already been used for zero-crossing detection. If the ratio is less than or equal to the specified percentage, the already specified zero-crossing detection phase is used, i.e., the selected detection phase is used as the zero-crossing detection phase, to accurately determine the zero-crossing detection phase for zero-crossing detection of the phase voltage. This allows for accurate overcurrent detection of the voltage phase with the maximum voltage value, ensuring that the relay contacts on the voltage phase with the maximum voltage value are not damaged, thereby increasing the relay's service life.

[0074] In one embodiment, following the first and / or second embodiments of the relay-based closing control method, a third embodiment of this application is proposed, which, after the step of obtaining the three-phase voltage values ​​of the relay, includes:

[0075] Step S101: If at least one of the first phase voltage value, the second phase voltage value, and the third phase voltage value is greater than a preset voltage threshold, the step of selecting the detection phase and determining the zero-crossing detection phase based on the first phase voltage value, the second phase voltage value, the third phase voltage value, and the preset voltage is executed.

[0076] In this embodiment, before determining the voltage zero-crossing detection phase, the need for zero-crossing detection can be determined primarily based on the three-phase voltage values. The main basis is to determine whether the current three-phase voltage values ​​pose a risk of damaging the relay contacts. By determining whether any of the first-phase voltage values ​​of the first voltage phase, the second-phase voltage value of the second voltage phase, and the third-phase voltage value of the third voltage phase on the power grid exceeds a preset voltage threshold, it is determined that there is a risk of damaging the relay contacts when at least one of the three voltage values ​​exceeds the preset voltage threshold. At this point, the step of selecting the detection phase based on the first-phase voltage value, the second-phase voltage value, the third-phase voltage value, and the preset voltage threshold is initiated. Alternatively, the voltage zero-crossing detection phase can be determined directly without considering the voltage magnitude, since the voltage is always present, and therefore, it is not necessary to detect the voltage magnitude before performing zero-crossing detection. The preset voltage threshold refers to a user-defined voltage threshold, which can be positively correlated with the voltage that the relay contacts can withstand. Further details can be found by referring to… Figure 3When the relay is closed for the first time, the voltage of phase A is designated as the zero-crossing detection phase (i.e., the preset voltage selection detection phase; of course, it can also be a phase selected by other users, such as using phase C as the preset voltage selection detection phase for the first closing). Then, it is determined whether zero-crossing detection control is needed for closing. This is done by detecting whether at least one phase voltage is greater than the minimum specified operating voltage (i.e., the preset voltage threshold, such as 60%Un, which can be adjusted according to actual conditions; Un is the relay's rated voltage). If any phase voltage is greater than the preset voltage threshold, it is determined that closing at this time would damage the relay contacts of that phase (the phase with the voltage greater than the preset voltage threshold). Therefore, the zero-crossing detection phase is further determined to pinpoint the zero-crossing voltage moment, and closing control is performed at the zero-crossing voltage moment. This avoids damage to the relay contacts and thus extends the relay's lifespan.

[0077] Furthermore, after obtaining the three-phase voltage values ​​of the relay, the process also includes:

[0078] Step S102: When the voltage values ​​of the first phase, the second phase, and the third phase are all less than or equal to the preset voltage threshold, control the relay to close.

[0079] In this embodiment, in addition to voltage zero-crossing detection, the relay can be controlled to close when the voltage values ​​of the first phase, the second phase, and the third phase are all less than or equal to a preset voltage threshold. That is, if it is determined that the three-phase voltage values ​​do not pose a risk of damage to the three contacts of the relay, the closing control can be performed directly. At the same time, the original selected detection phase can be used for the next relay closing control.

[0080] In one embodiment, the first, second, and / or third embodiments of the relay-based closing control method are followed by a fourth embodiment of this application, which includes the step of controlling the relay closing based on the voltage zero-crossing detection phase, comprising:

[0081] Step S21: Obtain the real-time voltage value of the voltage zero-crossing detection phase;

[0082] Step S22: When the real-time voltage value is the preset zero-crossing voltage value, control the relay to close.

[0083] In this embodiment, after determining the voltage zero-crossing detection phase, the closing of the relay is controlled. By acquiring the real-time voltage value of the voltage zero-crossing detection phase, and then controlling the relay to close when the real-time voltage value is a preset zero-crossing voltage value, that is, controlling the relay to close at the voltage zero-crossing point on the voltage zero-crossing detection phase, the average instantaneous inrush current borne by the three contacts of the relay is minimized at this time, thereby protecting the relay contacts and improving the relay's service life. Further, refer to... Figure 3After determining the voltage zero-crossing detection phase, voltage zero-crossing detection is performed on the corresponding phase voltage. When the voltage of the voltage zero-crossing detection phase crosses zero, the relay is closed, thereby reducing the instantaneous inrush current to the relay contacts and improving the relay's service life.

[0084] In one embodiment, after the step of controlling the closing of the relay based on the voltage zero-crossing detection phase, the following steps are included:

[0085] Step S23: Determine the closing action duration corresponding to the zero-crossing voltage detection;

[0086] Step S24: Determine the closing interval duration of the voltage zero-crossing detection phase based on the closing action duration and the preset voltage cycle duration.

[0087] In this embodiment, after the voltage zero-crossing detection phase control relay closes, the closing time is also recorded so that closing control can be performed in the next cycle. Before performing the entire relay closing control, the closing action time of each phase (A, B, and C) at the zero-crossing voltage point must be obtained and saved separately. After determining the closing action time of the relay controlling the zero-crossing detection phase, the closing action time corresponding to the zero-crossing detection will be determined. Then, based on the closing action time and the preset voltage cycle time, the closing interval time for the zero-crossing detection phase is determined. The closing action time refers to the time from receiving the command to completing the closing. The closing interval time refers to the closing interval between two zero-crossing points, ensuring that the closing action can proceed at the next zero-crossing point. The preset voltage cycle time refers to the cycle time of the three-phase voltage. Assuming the preset voltage cycle time is As, the closing action time is Bs, and n is the action proximity value, the closing interval time can be determined as As - Bs - n. For example, if As is 20ms, Bs is 11ms, and n is 0.2ms, then the tripping interval time is 20 - 11 - 0.2 = 8.8ms. Further details can be found by referring to... Figure 3 After detecting a zero-crossing voltage in the corresponding phase, the relay's operating time at the zero-crossing point is combined with the previously acquired relay action time. A suitable delay is then made before the relay closes, ensuring that the relay contacts open just before the next cycle's zero-crossing point for the designated zero-crossing detection phase. This serves as the basis for subsequent relay control on that phase. It's worth noting that once the closing interval duration for each voltage phase is determined, the closest closing interval duration can be directly determined in subsequent closing control. Closing control can then be based on this time point, improving closing control efficiency. Furthermore, since all closing interval durations arrive at the zero-crossing point, closing at the highest voltage point can be avoided, effectively extending the relay's lifespan.

[0088] In one embodiment, based on the first, second, third, and / or fourth embodiments of the relay-based closing control method, a fifth embodiment of the relay-based closing control method of this application is proposed, wherein the relay-based closing control method further includes:

[0089] Step S00: After receiving a trip control command each time, select the first voltage phase, the second voltage phase, and the third voltage phase on the three-phase circuit as preset voltage detection phases in a polling manner.

[0090] In this embodiment, to ensure the uniformity of the lifespan of the three contacts of the relay and the uniformity of the control over the three-phase power grid, after each receiving of the closing control command, the first, second, and third voltage phases of the three-phase circuit can be selected as preset voltage detection phases in a polling manner. This determines the closing control time corresponding to the first, second, and third voltage phases, ensuring the uniformity of the relay's zero-crossing closing control across different voltage phases. This, in turn, ensures the uniformity of the lifespan of each contact on the relay, preventing the problem of increased relay usage costs due to frequent damage to a single relay contact. The closing control command refers to the command that requires closing control of the relay.

[0091] Furthermore, following the steps of closing the phase-controlled relay based on the voltage zero-crossing detection, the process includes:

[0092] Step S30: If the voltage zero-crossing detection phase is a preset voltage selection detection phase, determine the next preset voltage selection detection phase, and perform the step of obtaining the three-phase voltage value of the relay based on the next preset voltage selection detection phase;

[0093] Step S40: If the voltage zero-crossing detection phase is not the preset voltage selection detection phase, determine the next preset voltage selection detection phase, and perform the step of obtaining the three-phase voltage value of the relay based on the next preset voltage selection detection phase, or perform the step of obtaining the three-phase voltage value of the relay.

[0094] In this embodiment, after closing control is performed based on the voltage zero-crossing detection phase, it can be determined whether the voltage zero-crossing detection phase is a preset voltage selection detection phase or not a selection detection phase, i.e., the situation where the voltage zero-crossing detection phase is changed is judged, and control can be performed based on the two situations. After selecting a certain selection detection phase, regardless of whether it is used, the next selection detection phase can be selected to perform the step of obtaining the three-phase voltage value of the relay. Alternatively, after selecting a certain selection detection phase, the next selection detection phase can be selected only after that selection detection phase is used to perform the step of obtaining the three-phase voltage value of the relay. This ensures the number of times each selection detection phase is used, making the closing control of the three voltage phases more uniform throughout the entire closing control process, ensuring uniform use of the relay contacts on the corresponding voltage phases, and ensuring the consistency of the relay contact lifespan.

[0095] Corresponding to the above embodiments, this application also proposes a three-phase energy meter.

[0096] like Figure 4 As shown, the three-phase energy meter in this application embodiment may include:

[0097] Relay 10 is connected to a three-phase circuit, such as power grid 200 (generally a three-phase relay, but it can also be a single-phase relay; this application describes it as a three-phase relay).

[0098] The closing controller 20 is connected to the control terminal of the relay 10.

[0099] The closing controller 20 is also used to perform the steps of the relay closing control method embodiment as described in any of the above.

[0100] In this embodiment, the three-phase energy meter can be applied to any three-phase energy meter. This embodiment takes a three-phase energy meter on the power grid as an example for illustration. The three-phase energy meter on the power grid includes a relay 10 and a closing controller 20.

[0101] According to the three-phase energy meter of this application embodiment, the closing controller 20 acquires the three-phase voltage values ​​of the relay, wherein the three-phase voltage values ​​include the first-phase voltage value of the first voltage phase, the second-phase voltage value of the second voltage phase, and the third-phase voltage value of the third voltage phase on the three-phase circuit connected to the relay; determines the voltage zero-crossing detection phase based on the first-phase voltage value, the second-phase voltage value, the third-phase voltage value, and a preset voltage selection detection phase; and controls the relay to close based on the voltage zero-crossing detection phase, so as to realize that the relay closes at the voltage zero-crossing point. By determining the voltage zero-crossing detection phase based on the first-phase voltage value, the second-phase voltage value, the third-phase voltage value, and the preset voltage selection detection phase on the three-phase circuit connected to the relay, the relay is controlled to close when the voltage of the voltage zero-crossing detection phase crosses zero. This avoids the problem in existing technologies where random closing might occur at maximum voltage (where the capacitive load environment causes a large inrush current at the relay contacts), potentially damaging the relay contacts. By controlling the relay to close when the voltage of the zero-crossing detection phase crosses zero, this phenomenon of closing at maximum voltage is avoided, thus improving the relay's lifespan. It's worth noting that a voltage acquisition instrument can be designed into the three-phase energy meter to collect the three-phase voltage values ​​and transmit them to the circuit breaker controller 20 for processing. Of course, the three-phase energy meter can also include more instruments, which will not be discussed here.

[0102] This application also provides a closing controller, as described above. Figure 5 , Figure 5 This is a schematic diagram of a closing controller module according to an embodiment of this application. The closing controller includes:

[0103] The data acquisition module A01 is used to acquire the three-phase voltage values ​​of the relay, wherein the three-phase voltage values ​​include the first phase voltage value of the first voltage phase, the second phase voltage value of the second voltage phase, and the third phase voltage value of the third voltage phase on the three-phase circuit connected to the relay.

[0104] The closing control module A02 is used to select the detection phase based on the first phase voltage value, the second phase voltage value, the third phase voltage value and the preset voltage to determine the voltage zero-crossing detection phase, and control the relay to close according to the voltage zero-crossing detection phase, so as to realize the relay closing at the voltage zero-crossing point.

[0105] This application also provides a storage medium, which is a computer storage medium.

[0106] The storage medium of this application stores a relay closing control program, which, when executed by a processor, implements the steps of the relay closing control method described above.

[0107] The method implemented when the relay closing control program running on the processor is executed can be referred to in various embodiments of the relay closing control method of this application, and will not be repeated here.

[0108] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0109] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0110] The above description is merely an optional embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the inventive concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A method for controlling the closing of a relay, characterized in that, The relay closing control method includes the following steps: Obtain the three-phase voltage values ​​of the relay, wherein the three-phase voltage values ​​include the first phase voltage value of the first voltage phase, the second phase voltage value of the second voltage phase, and the third phase voltage value of the third voltage phase in the three-phase circuit connected to the relay; The zero-crossing detection phase is determined based on the first phase voltage value, the second phase voltage value, the third phase voltage value, and a preset voltage. The relay is then controlled to close based on the zero-crossing detection phase, thereby enabling the relay to close at the zero-crossing point. The step of determining the zero-crossing detection phase based on the first phase voltage value, the second phase voltage value, the third phase voltage value, and the preset voltage includes: The maximum voltage value among the first phase voltage value, the second phase voltage value, and the third phase voltage value is determined; if the voltage phase corresponding to the maximum voltage value is a preset voltage selection detection phase, the selected detection phase is determined as the voltage zero-crossing detection phase; if the voltage phase corresponding to the maximum voltage value is not a preset voltage selection detection phase, the target voltage value corresponding to the selected detection phase among the first phase voltage value, the second phase voltage value, and the third phase voltage value is determined, and the voltage zero-crossing detection phase is determined based on the maximum voltage value and the target voltage value.

2. The relay closing control method as described in claim 1, characterized in that, The step of determining the voltage zero-crossing detection phase based on the maximum voltage value and the target voltage value includes: Determine the voltage difference between the maximum voltage value and the target voltage value; If the voltage difference is greater than a preset difference threshold, the voltage phase corresponding to the maximum voltage value is taken as the voltage zero-crossing detection phase. If the voltage difference is less than or equal to a preset difference threshold, the selected detection phase is used as the voltage zero-crossing detection phase.

3. The relay closing control method as described in claim 1, characterized in that, The step of controlling the relay to close based on the voltage zero-crossing detection phase includes: Obtain the real-time voltage value of the voltage zero-crossing detection phase; When the real-time voltage value is a preset zero-crossing voltage value, the relay is controlled to close.

4. The relay closing control method as described in claim 1, characterized in that, After the step of controlling the relay to close based on the voltage zero-crossing detection phase, the following steps are included: Determine the closing action duration corresponding to the voltage zero-crossing detection; The closing interval duration of the voltage zero-crossing detection phase is determined based on the closing action duration and the preset voltage cycle duration.

5. The relay closing control method as described in claim 1, characterized in that, After the step of obtaining the three-phase voltage value of the relay, the following steps are included: If at least one of the first phase voltage value, the second phase voltage value, and the third phase voltage value is greater than a preset voltage threshold, the step of selecting a detection phase and determining the zero-crossing detection phase based on the first phase voltage value, the second phase voltage value, the third phase voltage value, and the preset voltage is executed.

6. The relay closing control method as described in claim 1, characterized in that, After the step of obtaining the three-phase voltage value of the relay, the method further includes: When the voltage values ​​of the first phase, the second phase, and the third phase are all less than or equal to a preset voltage threshold, the relay is controlled to close.

7. The relay closing control method according to any one of claims 1 to 6, characterized in that, The relay closing control method further includes: After receiving a closing control command each time, the first voltage phase, the second voltage phase, and the third voltage phase are selected as the preset voltage selection and detection phases in a polling manner.

8. The relay closing control method as described in claim 7, characterized in that, After the step of controlling the relay to close based on the voltage zero-crossing detection phase, the following steps are included: If the voltage zero-crossing detection phase is a preset voltage selection detection phase, determine the next preset voltage selection detection phase, and perform the step of obtaining the three-phase voltage value of the relay based on the next preset voltage selection detection phase; If the voltage zero-crossing detection phase is not the preset voltage selection detection phase, determine the next preset voltage selection detection phase, and perform the step of obtaining the three-phase voltage value of the relay based on the next preset voltage selection detection phase, or perform the step of obtaining the three-phase voltage value of the relay.

9. A three-phase electricity meter, characterized in that, The three-phase energy meter includes: The relay is connected to a three-phase circuit; A closing controller, wherein the closing controller is connected to the control terminal of the relay; The closing controller is also used to perform the steps of the closing control method for the relay as described in any one of claims 1 to 8.

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