Isolation switch and control method thereof

Abstract

The invention relates to an isolation switch and a control method thereof. The isolating switch comprises a management system (100) which judges the opening and closing state of the isolating switch by receiving a contact signal of the isolating switch (200); a processing unit (210) which receives the control signal from the management system (100) and transmits a driving signal; the driving motor (230) is used for controlling the executing mechanism (240) to act according to the driving signal; the executing mechanism (240) is driven by the driving motor (230) to perform opening and closing actions of the isolating switch (200); the current sampling unit (250) is used for sampling a current signal of the driving motor (230) and feeding back the sampled current to the processing unit (210), and in the processing unit (210), the actual position of the execution mechanism (240) is judged according to a comparison result of the sampled current and a threshold value.

Description

Technical Field

[0001] The present disclosure relates to an isolating switch and a control method thereof, and in particular to a remote-controlled isolating switch using current positioning and a control method thereof. Background Art

[0002] Energy storage industries such as electrochemical energy storage systems, power generation side energy supply, industrial and commercial energy storage, etc. usually adopt the protection and control scheme of high-voltage contactor + pre-charging contactor + isolating switch to realize core functions such as isolation function, electric separation and combination, and equalization and pre-charging. Among them, the high-voltage contactor cannot withstand large currents due to its own structural characteristics and is prone to adhesion, resulting in operational risks.

[0003] The fusion switch and semi-fusion switch with innovative mechanical and electrical structures that have appeared on the market adopt an integrated structure. The fusion switch can completely replace the above-mentioned protection and control scheme of high-voltage contactor + pre-charge contactor + isolating switch, while the semi-fusion switch can replace the high-voltage contactor + isolating switch part of the above protection and control scheme. The fusion switch and semi-fusion switch are used in the high-voltage box of the energy storage cabinet of the energy storage system. They have the main switch group contacts and can realize remote opening and closing control with the electric operating mechanism. At the same time, they have the local manual opening and closing function, which can replace the load isolation switch and the main contactor in the high-voltage box of the conventional energy storage cabinet, and can optimize the user's wiring, reduce the installation time, and reduce the user's overall procurement cost.

[0004] Whether it is a traditional disconnector, an integrated fusion switch or a semi-fusion switch, when the switch actuator is driven by a motor to reach the closing or opening position, the traditional solution generally locates the actuator by collecting the signal of the micro switch, that is, the position of the actuator is obtained by linking the micro switch with the actuator. However, this positioning method has several problems:

[0005] 1. Mechanical switches such as micro switches are prone to failure, and if dual micro switches are used, they will take up a large space;

[0006] 2. The installation position of the micro switch has high requirements. If the micro switch is installed too far forward, when the micro switch is actuated, the actuator movement position has not yet allowed the spring to be released; if the micro switch is installed too far back, after the micro switch is actuated, the actuator has not stopped moving after the spring is released. At this time, the drive motor that drives the actuator is prone to stalling, and the actuator is prone to impact, affecting the reliability of the actuator's action.

[0007] Therefore, a solution is proposed for the above positioning problems of traditional isolating switches, integrated fusion switches and semi-fusion switches. Summary of the invention

[0008] The present invention provides a control method for an isolating switch, which can remotely control the opening and closing of the switch through electrical signals. At the same time, by eliminating the mechanical microswitch positioning and detecting the current change of the driving motor driving the isolating switch, the position of the opening and closing of the switch is determined, thereby effectively improving the reliability of the opening and closing action and reducing the cost of the isolating switch.

[0009] According to one aspect of the present disclosure, there is provided an isolating switch, comprising: a management system, which determines the opening and closing state of the isolating switch by receiving a contact signal of the isolating switch; a processing unit, which receives a control signal from the management system and sends a drive signal; a drive motor, which controls an actuator to perform an action according to the drive signal; the actuator, which performs the opening and closing action of the isolating switch under the drive of the drive motor; and a current sampling unit, which samples the current signal of the drive motor and feeds the sampled current back to the processing unit, wherein in the processing unit, the actual position reached by the actuator is determined based on the comparison result between the sampled current and a threshold value.

[0010] After the drive motor is started, the sampled current is compared with the first threshold.

[0011] When the sampling current is greater than the first threshold, it is determined that the actuator has passed the idling stroke and the pre-full stroke and is about to enter the main stroke, the spring of the actuator has been compressed, and the sampling current is compared with the second threshold.

[0012] When the sampled current is less than the second threshold, it is determined that the actuator has reached the vicinity of the dead point in the main stroke, and the sampled current is compared with the third threshold.

[0013] When the sampled current is greater than the third threshold, it is determined that the actuator has reached a predetermined opening and closing position, and the drive motor is stopped.

[0014] After the drive motor is started, the sampled current is compared with a fourth threshold value. When the sampled current is greater than the fourth threshold value, it is determined that the actuator reaches a predetermined position of opening and closing the switch, the drive motor is blocked, and the drive motor is stopped.

[0015] Therein, a predetermined delay occurs before the sampled current is compared with the threshold value.

[0016] According to another aspect of the present disclosure, a method for an isolating switch is provided, comprising: judging an actual position reached by an actuator of the isolating switch according to a comparison result between a sampled current of a driving motor of the isolating switch and a threshold value.

[0017] After the drive motor is started, the sampled current is compared with the first threshold.

[0018] When the sampling current is greater than the first threshold, it is determined that the actuator has passed the idling stroke and the pre-full stroke and is about to enter the main stroke, the spring of the actuator has been compressed, and the sampling current is compared with the second threshold.

[0019] When the sampled current is less than the second threshold, it is determined that the actuator has reached the vicinity of the dead point in the main stroke, and the sampled current is compared with the third threshold.

[0020] When the sampled current is greater than the third threshold, it is determined that the actuator has reached a predetermined opening and closing position, and the drive motor is stopped.

[0021] After the drive motor is started, the sampled current is compared with the fourth threshold value.

[0022] After the drive motor is started, the sampled current is compared with the fourth threshold value. When the sampled current is greater than the fourth threshold value, it is determined that the actuator reaches the predetermined position of opening and closing the switch, the drive motor is blocked, and the drive motor is stopped.

[0023] Therein, a predetermined delay occurs before the sampled current is compared with the threshold value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The aspects, features and advantages of the present disclosure will become clearer and easier to understand through the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0025] Figure 1 A schematic diagram showing the operation between a battery management system and an isolating switch of a battery high voltage cabinet according to an embodiment of the present disclosure;

[0026] Figure 2 A schematic diagram showing the movement process of the actuator of the disconnector according to an embodiment of the present disclosure;

[0027] Figure 3 A schematic diagram showing a curve of torque variation during movement of an actuator of an isolating switch according to an embodiment of the present disclosure; and

[0028] Figure 4 A flow chart of a method for determining the closing or opening position of an isolating switch by using current positioning according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0029] The present disclosure will be described in detail below with reference to exemplary embodiments of the present disclosure. However, the present disclosure is not limited to the embodiments described herein, and it can be implemented in many different forms. The described embodiments are only used to make the present disclosure thorough and complete, and to fully convey the concept of the present disclosure to those skilled in the art. The features of the various embodiments described can be combined or replaced with each other, unless explicitly excluded or should be excluded according to the context.

[0030] The isolating switch of the present invention controls the opening and closing of the isolating switch remotely through pulse signals, and eliminates the positioning method of mechanical switches such as micro switches. Instead, the opening and closing positions of the isolating switch are determined by detecting the current changes of the motor driving the actuator, which effectively improves the reliability of the opening and closing actions of the isolating switch and reduces the cost of the isolating switch.

[0031] The following takes a battery high-voltage cabinet of an electrochemical energy storage system as an example to illustrate the technical solution of the present invention.

[0032] Figure 1 A schematic diagram showing the operation between a battery management system 100 and an isolating switch 200 of a battery high voltage cabinet according to an embodiment of the present disclosure is shown.

[0033] The isolating switch 200 includes a processing unit 210, a motor drive unit 220, a drive motor 230, an actuator 240, and a current sampling unit 250. The isolating switch 200 also includes a disconnecting unit (not shown). When the disconnecting unit is opened or closed under the push of the actuator 240, the external OF trigger structure in the disconnecting unit will be linked with the OF accessory (not shown) to achieve triggering. The OF accessory sends an OF signal representing the opening and closing state based on the linkage.

[0034] The battery management system 100 determines the opening and closing state of the disconnector 200 by receiving an OF signal (i.e., a contact signal) from an OF accessory based on the opening and closing state of the disconnecting unit driven by the actuator 240. The battery management system 100 sends a control signal to the processing unit 210 of the disconnector 200 according to demand, and the processing unit 210 controls the motor drive unit 220 to drive the drive motor 230 according to the received control signal, thereby controlling the disconnector 200 to perform the opening and closing action.

[0035] The current sampling unit 250 samples the current signal of the driving motor 230 , and feeds the sampled current signal back to the processing unit 210 and the motor driving unit 220 .

[0036] The motor driving unit 220 that receives the current sampling signal compares the current sampling signal with a specific threshold value, and controls the current limiting action and driving action of the motor driving unit 220 according to the comparison result.

[0037] The processing unit 210 that receives the current sampling signal compares the current sampling signal with a specific threshold value, and determines whether the actuator 240 of the disconnector 200 has reached the predetermined opening and closing position based on the comparison result, so as to provide the opening and closing position information to the panel indication component (not shown) of the disconnector 200, and the panel indication component further displays the status indication of the main contacts.

[0038] Figure 2 A schematic diagram showing the movement process of the actuator of the isolating switch according to an embodiment of the present disclosure is shown.

[0039] Figure 3 A schematic diagram of a curve showing a change in torque during the movement of an actuator of an isolating switch according to an embodiment of the present disclosure is shown.

[0040] like Figure 2 As shown, in Figure 2 During the movement of the actuator indicated by 1-2, the torque r gradually decreases, and near the dead point of the actuator structure, r approaches 0, resulting in a very small torque. Once the dead point is passed, the energy stored in the spring of the actuator structure is automatically and quickly released, pushing the actuator to the closing or opening position.

[0041] The torque variation curve of the measured mechanism motion is as follows: Figure 3 As shown, the torque T∝F*r. Based on this characteristic of the torque, the shape of the curve can be identified by identifying the change of the torque curve (three torque thresholds), so as to determine whether the disconnector has been closed or opened.

[0042] like Figure 3 As shown, threshold 1 indicates the torque generated by the actuator compressing the spring; threshold 2 indicates the torque of the actuator reaching the dead point; threshold 3 indicates the torque generated by the spring releasing energy and pushing the contacts of the disconnector to open and close.

[0043] like Figure 3 As shown, in the idling stroke stage, the drive motor of the disconnector is idling, so the torque is extremely low, almost close to zero; in the pre-full stroke stage, the drive motor of the disconnector drives the pre-charge contactor to work, and the torque increases slightly.

[0044] In the main-split stroke stage (for example, after it is greater than threshold 1, it can be determined that the spring of the actuator has been compressed), the drive motor of the disconnector drives the actuator structure to move, and the torque increases and is maintained until the actuator reaches near the dead point (for example, after it is less than threshold 2, where the torque decreases rapidly near the dead point), and then continues the main-split stroke to reach the peak torque (for example, after it is greater than threshold 3), completing the opening and closing actions.

[0045] Because the closing or opening position of the disconnector can be determined based on the torque, and the current of the drive motor is proportional to the torque of the actuator, the torque of the actuator can be determined by sampling the current of the drive motor and comparing the current sampling signal with several specific thresholds. The closing or opening position of the disconnector can be determined based on the comparison results, that is, current positioning is used to determine the closing or opening position of the disconnector.

[0046] In addition, when the drive motor is abnormally blocked (i.e., the actuator has reached the predetermined position of the opening and closing switch), the blocking torque at this time is much higher than the normal torque, and the sampling current of the drive motor is also much higher than any of the above thresholds 1-3. A threshold 4 greater than any of the above thresholds 1-3 can be set according to the technical parameters of different disconnectors and specific experimental data. When the sampling current of the drive motor is greater than the threshold 4, it can be considered that a blockage has occurred, the actuator has reached the predetermined position of the opening and closing switch, and the action of the drive motor must be stopped, thereby preventing the drive motor from burning.

[0047] Figure 4 A flow chart of a method for determining the closing or opening position of an isolating switch by using current positioning according to an embodiment of the present disclosure is shown.

[0048] Figure 4 The method adopts a combination of two methods. After the motor is started in step 410, the method 1 on the left (consisting of steps 420, 430, 440, 450, 460, and 470) and the method 2 on the right (consisting of steps 480 and 490) start to act at the same time. When method 1 determines that the opening and closing action of the actuator is in place, the drive motor is stopped immediately. When method 2 determines that the drive motor driving the actuator is blocked (that is, it means that the actuator has reached the predetermined position of opening and closing), the drive motor is stopped immediately. The drive motor can be stopped when any one of method 1 and method 2 determines that the actuator is in place.

[0049] Method 1: Figure 3 The three thresholds (ie, thresholds 1-3) shown are used to identify the motion curve of the actuator to determine whether the actuator has reached a predetermined position.

[0050] Specifically, in step 420, the judgment delay timer T0 (for example, 80ms) is first started. The main function of the delay timer T0 is to avoid sampling the large current generated by the start-up of the drive motor. When the drive motor starts, a large current will appear because the speed is 0. Sampling the large current at this time will affect the judgment of the torque. When the delay timer T0 expires, step 430 is performed.

[0051] In step 430, it is determined whether the sampled current of the drive motor is greater than threshold 1. When the sampled current of the drive motor is greater than threshold 1 (that is, after being greater than threshold 1, it can be fully determined that the spring of the actuator has been compressed), step 440 is performed. When the sampled current of the drive motor is less than or equal to threshold 1, step 430 is looped for comparison and judgment.

[0052] In step 440, a judgment delay timer T1 (e.g., 100ms) is started. The main function of the delay timer T1 is to wait for the actuator to pass the dead point. The actuator will move toward the dead point during this period of time. During this period of time, there is no need to judge the torque. After this period of time, it can be considered that it is close to the expected dead point position and it is necessary to start detecting the torque. Therefore, when the delay timer T1 expires, step 450 is performed.

[0053] In step 450, it is determined whether the sampled current of the drive motor is less than threshold 2. When the sampled current of the drive motor is less than threshold 2 (i.e., after being less than threshold 2, the actuator is very close to the dead point), step 460 is performed. When the sampled current of the drive motor is greater than or equal to threshold 2, step 450 is looped for comparison and determination.

[0054] In step 460, a judgment delay timer T2 (e.g., 40ms) is started, mainly to wait for the spring release of the actuator to be completed. Since the dead point position of the actuator is not very accurate and fixed, the main function of the delay timer T2 is to ignore the signal changes during this period of time, and only care about how to compare and judge after the delay timer T2 expires. When the delay timer T2 expires, step 470 is performed.

[0055] In step 470, it is determined whether the sampled current of the drive motor is greater than threshold 3 (i.e., after being greater than threshold 3, the actuator completes the opening and closing action). When the sampled current of the drive motor is greater than threshold 3, step 500 is performed. When the sampled current of the drive motor is less than or equal to threshold 3, the process jumps to step 420.

[0056] In step 500, the action of the driving motor is stopped, and it is considered that the disconnector has completed closing or opening, and a closing or opening signal is sent to the panel indication component of the disconnector, and the panel indication component further displays the status indication of the main contact.

[0057] The execution of method 1 itself relies on the judgment of the torque change when the actuator is working normally. However, if the driving motor driving the actuator is blocked, it is difficult to make an accurate judgment using method 1.

[0058] Therefore, method 2 must be performed simultaneously. Method 2 is applied to a situation such as a stall in the driving motor driving the actuator, and by continuously detecting whether the current is greater than the threshold value 4 in step 480, and detecting whether the state of the current being greater than the threshold value 4 has lasted for T3 time (e.g., 500 ms) in step 490, it is determined whether the actuator has reached the predetermined position.

[0059] Specifically, in step 480, it is determined whether the sampled current of the drive motor is greater than threshold 4. When the sampled current of the drive motor is greater than threshold 4, step 490 is performed. When the sampled current of the drive motor is less than or equal to threshold 4, step 480 is looped for comparison and determination.

[0060] In step 490, a judgment delay timer T3 (e.g., 500ms) is started, which is mainly used to judge whether the drive motor is blocked. When the delay timer T3 expires, it can be judged that the drive motor is blocked, that is, the actuator has reached the predetermined position of the opening and closing, and then step 500 is performed.

[0061] In step 500, the action of the driving motor is stopped, and it is considered that the disconnector has completed closing or opening, and a closing or opening signal is sent to the panel indication component of the disconnector, and the panel indication component further displays the status indication of the main contact.

[0062] In method 2, the stall time (delay timer T3) is used to determine whether the actuator can continue to move. This can ensure that: when the previous method 1 cannot be used to stop the action of the drive motor, method 2 is used to stop the action of the drive motor, thereby stopping the actuator from running.

[0063] The thresholds 1-4 and the values ​​of the timers T0-T3 in method 1 and method 2 are set according to the technical parameters of different isolating switches and specific experimental data.

[0064] The effect of using the current to determine the positioning according to the present invention is very close to the effect of mechanical switch positioning.

[0065] The hardware computing device described in the present disclosure may be implemented in its entirety or in parts thereof through various suitable hardware means, including but not limited to FPGA, ASIC, SoC, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0066] The block diagrams of circuits, devices, apparatuses, equipment, and systems involved in the present disclosure are only illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these circuits, devices, apparatuses, equipment, and systems may be connected, arranged, or configured in any manner as long as the desired purpose can be achieved.

[0067] Those skilled in the art should understand that the above-mentioned specific embodiments are merely examples and not limitations, and various modifications, combinations, partial combinations and replacements may be made to the embodiments of the present disclosure according to design requirements and other factors. As long as they are within the scope of the attached claims or their equivalents, they belong to the scope of rights to be protected by the present disclosure.

Claims

1. An isolating switch (200), comprising: A management system (100) determines the opening and closing state of the isolating switch by receiving a contact signal of the isolating switch (200); A processing unit (210) receives a control signal from the management system (100) and sends a drive signal; A driving motor (230) controls an actuator (240) to perform an action according to a driving signal; An actuator (240) performs opening and closing actions of the isolating switch (200) under the drive of the driving motor (230); A current sampling unit (250) samples a current signal of the driving motor (230) and feeds back the sampled current to the processing unit (210). Wherein, in the processing unit (210), the actual position reached by the actuator (240) is determined based on the comparison result between the sampled current and the threshold value.

2. The isolating switch according to claim 1, wherein After the drive motor (230) is started, the sampled current is compared with a first threshold value (threshold value 1).

3. The isolating switch according to claim 2, wherein When the sampled current is greater than a first threshold value (threshold value 1), it is determined that the actuator (240) has passed through an idling stroke and a pre-full stroke and is about to enter a main stroke, the spring of the actuator (240) has been compressed, and the sampled current is compared with a second threshold value (threshold value 2).

4. The isolating switch according to claim 3, wherein When the sampled current is less than the second threshold value (threshold value 2), it is determined that the actuator (240) has reached the vicinity of a dead point in the main stroke, and the sampled current is compared with a third threshold value (threshold value 3).

5. The isolating switch according to claim 4, wherein When the sampled current is greater than a third threshold value (threshold value 3), it is determined that the actuator (240) has reached a predetermined opening and closing position, and the drive motor (230) is stopped.

6. The isolating switch according to claim 1, wherein After the drive motor (230) is started, the sampled current is compared with a fourth threshold value (threshold 4), When the sampled current is greater than a fourth threshold value (threshold value 4), it is determined that the actuator (240) has reached a predetermined opening and closing position, the drive motor (230) is blocked, and the drive motor (230) is stopped.

7. The isolating switch according to claim 1, wherein A predetermined delay elapses before the sampled current is compared to the threshold.

8. A method for isolating a switch, comprising: The actual position reached by the actuator of the isolating switch is determined based on the comparison result between the sampled current of the driving motor of the isolating switch and the threshold value.

9. The method of claim 8, further comprising: After the drive motor is started, the sampled current is compared with the first threshold.

10. The method of claim 9, further comprising: When the sampling current is greater than the first threshold, it is determined that the actuator has passed the idling stroke and the pre-full stroke and is about to enter the main stroke, the spring of the actuator has been compressed, and the sampling current is compared with the second threshold.

11. The method of claim 10, further comprising: When the sampled current is less than the second threshold, it is determined that the actuator has reached the vicinity of the dead point in the main stroke, and the sampled current is compared with the third threshold.

12. The method of claim 11, further comprising: When the sampled current is greater than the third threshold, it is determined that the actuator reaches a predetermined opening and closing position, and the drive motor is stopped.

13. The method of claim 8, further comprising: After the drive motor is started, the sampled current is compared with the fourth threshold. When the sampled current is greater than the fourth threshold value, it is determined that the actuator reaches a predetermined opening and closing position, the drive motor is blocked, and the drive motor is stopped.

14. The method of claim 8, further comprising: A predetermined delay elapses before the sampled current is compared to the threshold.

Images