System and method for detecting discrete open and closed states of electrical switching device

Abstract

An apparatus for use in an electrical switching device that includes an operating mechanism having an energy storage device, a cam assembly, a polar axis, and separable contacts. The apparatus comprises: a holding device; an energy release detector configured to be disposed adjacent to the cam assembly and to detect an energy release state of the energy storage device based on a position of the cam assembly; a pole shaft position detector configured to be coupled to the pole shaft and detect an open and closed state of the separable contact based on a position of the pole shaft; and a switching device monitor coupled to the detectors and configured to receive data from the detectors, analyze the data, and perform control and / or diagnosis on the electrical switching device based on the analysis, the data including the detected energy release state and the detected open and closed states.

Description

Technical Field

[0001] The disclosed concept generally relates to a system and method for circuit protection, and more particularly to a system and method for detecting discrete open and close states (fully open and fully closed states) in an air circuit breaker. Background Technology

[0002] Electrical switching devices (such as, but not limited to, circuit breakers) are used in power distribution systems to protect electrical conductors and equipment from abnormal current conditions (such as, but not limited to, short circuits, ground faults, overloads, or overcurrents). Electrical switching devices utilize an energy storage device in the form of one or more large closing springs to close the contacts of the device. These devices also include one or more opening springs that rapidly separate the contacts to interrupt the current flowing in the power supply circuit. One or both of the closing and opening springs can be a single spring or multiple springs.

[0003] Energy storage circuit breakers (such as, but not limited to, air circuit breakers) are electrical switching devices used in industrial applications. An energy storage circuit breaker is an automatically operating electrical switching device that uses separable contacts to interrupt current, protecting the circuit from damage caused by excessive current under abnormal current conditions. The primary function of the energy storage circuit breaker is to interrupt current flow upon detection of an abnormal current condition. Air circuit breakers utilize energy storage devices to close and open the contact structure. The energy stored in the device is used to close the air circuit breaker. Typically, the energy stored in the closing spring is transferred to the moving contact carrier of the air circuit breaker via a drive cam and a drive coupling. The drive cam, having a variable radius cam profile, is rotated by the closing spring. The drive coupling includes a drive roller on a main link connected to the polar shaft of the air circuit breaker. A latching assembly latches the drive roller against the drive cam profile, causing the drive cam to rotate the polar shaft (connected to the moving contact carrier in each pole) via the rotation of the closing spring, thereby closing the contacts.

[0004] To extend the life of air circuit breakers and maximize their reliability, it is crucial to perform maintenance, control, and / or diagnostics on them. For accurate diagnostics, analyzing closing and opening times and identifying discrete fully closed positions of the circuit breaker are particularly important. For example, making current release (MCR) is used to prevent the circuit breaker from stalling during closing when a fault current exceeds its full closing capacity. MCR is a self-protection feature employed in many modern power circuit breakers and is designed to trip the circuit breaker immediately upon detecting a large fault current exceeding its "closing and latching" threshold. That is, when a high current is detected (exceeding the level that the closing spring is designed to overcome to fully close the circuit breaker mechanism) and the circuit breaker mechanism has not yet closed, the MCR function releases the trip latch (i.e., opens the circuit breaker). This prevents stalling during closing in these high-current situations (where more closing energy (force) than the closing spring can store). Therefore, when performing MCR, the identification of the fully closed state and the precise timing of the fully closed state are crucial for distinguishing between "closure during a fault" and "fault occurring after closure".

[0005] While a simple full-closure detection switch is sufficient to detect the fully closed position of some types of air circuit breakers (e.g., but not limited to, those with over-toggle type mechanisms), such a simple full-closure detection switch cannot identify the discrete closed positions of air circuit breakers utilizing under-toggle mechanisms. In circuit breakers with under-toggle mechanisms, identifying the fully closed state based on the rotation of the detection pole axis is extremely difficult because rotation varies significantly due to various factors, particularly the elasticity of the components and assemblies of the circuit breaker mechanism. To address this variation, time-delay switches have traditionally been used instead of simple pole axis position sensors to identify the circuit breaker's near-closed position and control MCR activation. However, the time-delay switch indicates the fully closed state of the circuit breaker several milliseconds after actual full closure. Based on the signal from the time-delay switch, the electronic trip unit will detect a high current flowing through the circuit breaker, which is not actually fully closed. Upon detecting the high current, the MCR circuit is triggered, and the electronic trip unit issues a trip command, thereby interrupting power distribution. Furthermore, incorrect determination of discrete open and / or closed positions of circuit breaker contacts leads to misdiagnosis of circuit breaker health, potentially resulting in catastrophic failure.

[0006] There is room for improvement in monitoring the health of electrical switching devices, particularly in identifying the fully closed state of electrical switching devices and the precise timing of the fully closed state. Summary of the Invention

[0007] These and other requirements are met by a device for use in an electrical switching device, the electrical switching device including an operating mechanism having an energy storage device, a cam assembly, a polar shaft coupled to the cam assembly, and a separable contact coupled to the polar shaft. The device includes: a holding device configured to be attached to the operating mechanism of the electrical switching device; a release detector attached to the holding device and configured to be positioned adjacent to the cam assembly, and detecting the release state of the energy storage device based on the position of the cam assembly; a polar shaft position detector attached to the holding device and configured to be coupled to the polar shaft, and detecting the open and closed state of the separable contact based on the position of the polar shaft; and a switching device monitor coupled to the release detector and the polar shaft position detector, the switching device monitor being configured to receive data from the detectors, analyze the data, and perform diagnostics and control on the electrical switching device based on the analysis, the data including the detected release state of the energy storage device and the detected open and closed state of the separable contact.

[0008] Another example embodiment includes an electrical switching device configured to connect a power source and a load. The electrical switching device includes: a housing; an energy storage assembly; an electrical trip unit (ETU) configured to interrupt current flow to the load in the event of an abnormal current; an operating mechanism coupled to the energy storage assembly and the ETU, the operating mechanism including an energy storage device, a cam assembly, a polar shaft coupled to the cam assembly, and a separable contact having a movable contact coupled to the load and a fixed contact coupled to the power source; a fully closed position monitor including a holding device configured to be attached to the operating mechanism of the electrical switching device; and an energy release detector attached to the holding device and configured to be disposed adjacent to the cam assembly. The device detects the energy release state of the energy storage device based on the position of the cam assembly; a polar axis position detector, attached to the holding device and configured to be coupled to the polar axis, detects the open and closed states of the separable contacts based on the position of the polar axis; and a switching device monitor, located within the ETU and coupled to the energy release detector and the polar axis position detector, the switching device monitor being configured to receive data from the detectors, analyze the data, and perform control and / or health diagnostics on the electrical switching device based on the analysis, the data including the detected energy release state of the energy storage device and the detected open and closed states of the separable contacts.

[0009] Another example embodiment provides a method for protecting an electrical switching device. The electrical switching device includes an operating mechanism having an energy storage device, a cam assembly, a polar shaft coupled to the cam assembly, and a separable contact coupled to the polar shaft. The method includes: detecting the energy release state of the energy storage device based on the position of the cam assembly; detecting the open and closed states of the separable contact based on the position of the polar shaft; and analyzing data including the detected energy release state of the energy storage device and the detected open and closed states of the separable contact. Attached Figure Description

[0010] A full understanding of the invention can be obtained from the following description of preferred embodiments when read in conjunction with the accompanying drawings, in which:

[0011] Figure 1 This is a perspective view of an exemplary electrical switching device according to a non-limiting exemplary embodiment of the disclosed concept;

[0012] Figure 2 yes Figure 1 A perspective view of the interior of an exemplary electrical switching device;

[0013] Figure 3 This is a partial block diagram of an exemplary electrical switching device including an exemplary device according to a non-limiting exemplary embodiment of the disclosed concept;

[0014] Figures 4 to 6 It shows Figure 1 Various states of an exemplary electrical switching device;

[0015] Figures 7 to 9 It shows Figure 1 The sequence of energy storage and release of the energy storage device in the operating mechanism of an exemplary electrical switching device;

[0016] Figures 10 to 12 It shows Figure 3 Exemplary devices; and

[0017] Figure 13 An exemplary logical sequence generated by an exemplary device is shown. Detailed Implementation

[0018] Directional phrases used herein (such as left, right, front, back, top, bottom and their derivatives) refer to the orientation of the elements shown in the figures and do not limit the claims unless expressly stated herein.

[0019] As used herein, the statement that two or more components are “joined” together means that the components are joined together directly or through one or more intermediate components.

[0020] Figures 1 to 13 An electrical switching device (e.g., but not limited to, an air circuit breaker) 1 and / or device 100 according to a non-limiting example embodiment of the disclosed concept is shown. Figure 1 and Figure 2 As shown, the air circuit breaker 1 includes a front housing 2, a rear housing 3, an energy storage handle 4, an electronic trip unit (ETU) 5, a spring and contact status indicator 6, a close and open breaker button 7, and an arc chute assembly 9. The air circuit breaker 1 can have three or four poles, each pole having an arc chamber (not shown). Figure 2 As shown, the air circuit breaker 1 includes an operating mechanism 10 disposed within the front housing 2. The operating mechanism 10 includes an energy storage device, such as, but not limited to, one or more closing springs 11 (see...). Figure 3 , Figures 7 to 12 The one or more closing springs are configured to store energy for closing the air circuit breaker 1. The closing spring 11 is energized by operation of the energy storage handle 4 or remotely via a motor actuator (not shown). The term "energy storage" here refers to storing mechanical energy by compressing or extending the closing spring 11 in preparation for closing the air circuit breaker 1. To store energy, the user begins by pulling the energy storage handle 4 (e.g., but not limited to pulling it 5 to 10 times), or a motor with a ratchet can be activated to drive the closing spring 11. The compressed spring 11 then stores energy in preparation for closing the separable contacts of the air circuit breaker 1. In response to a predetermined characteristic of the current flowing through the circuit breaker 1, the ETU 5 is activated via the polar axis 28 (see...). Figures 7 to 9 The rotation of the spring 11 actuates the operating mechanism 10 to disconnect all poles of the circuit breaker. The spring and contact status indicator 6 indicates the state of the closing spring 11 (released or stored) and the state of the contacts 15 and 16 (open or closed). Furthermore, the operating mechanism 10 includes a reference... Figures 10 to 13 Further discussion of the exemplary novel device 100.

[0021] Figure 3 This is a partial block diagram of an air circuit breaker 1 according to a non-limiting example embodiment of the disclosed concept. The operating mechanism 10 includes a closing spring 11, a cam assembly 20, a device 100, a pole shaft 28, a movable contact carrier 14 having a movable contact 15 and connected to the pole shaft 28 and the load conductor 13, and a fixed contact 16 connected to the line conductor 12. Figures 4 to 6As shown, the moving contact carrier 14 rotates between an open and closed position via an operating mechanism 10 to open and close the separable contacts 15 and 16. During the closing operation, the moving contact carrier 14 of the air circuit breaker 1 moves the moving contact 15 to contact the stationary contact 16. Therefore, the term "closing" here refers to the release of stored energy to drive the contacts 15 and 16 to close rapidly (e.g., but not limited to 20 ms to 30 ms). Reference Figures 4 to 9 The basic functions of the air circuit breaker 1 are discussed, including the closing and opening of contacts 15 and 16, and the energy storage and release of the closing spring 11.

[0022] exist Figure 4 In the circuit breaker 1, the circuit breaker is in the open and release mode. In this open and release mode, contacts 15 and 16 open and spring 11 closes. Figures 4 to 6 (Not shown in the image) has already released energy. Figure 5 In the circuit breaker 1, the circuit breaker is in the disconnect and energy storage mode. In this mode, contacts 15 and 16 remain open, but the closing spring 11 stores energy. Figure 6 In the circuit breaker 1, the air circuit breaker 1 is in the closed and released mode. In this closed and released mode, the contacts 15 and 16 are closed and the closing spring 11 is released.

[0023] Figures 7 to 9The sequence of energy storage and release of the closing spring 11 is shown. As shown in these figures, the closing spring 11 is fixed at one end and coupled to the rocker arm 17 at the other end. The operating mechanism 10 also includes a cam assembly 20. The cam assembly includes a camshaft 23, an energy storage cam 21, and a drive cam 22. The cam assembly 20 is, for example, but not limited to, a 360° mechanism that compresses the closing spring 11 to store energy during a portion of the rotation and rotates during the remainder of the rotation by releasing the energy stored in the closing spring 11. This is achieved by the engagement of the rocker arm roller 18 with the energy storage cam 21. The prestress on the closing spring 11 maintains the engagement of the rocker arm roller 18 with the energy storage cam 21, which has an energy storage portion 21a and a closed (non-energy storage) portion 21b. The diameter of the energy storage portion 21a at the point of engagement with the rocker arm roller 18 increases as the energy storage cam 21 rotates counterclockwise. The diameter of the closing portion 21b decreases as the energy storage cam 21 rotates against the rocker arm roller 18, and the spring 11 drives the energy storage cam 21 counterclockwise when the latching mechanism (e.g., the stop roller 40) is released. The energy storage portion 21a is configured such that a substantially constant torque is required to compress the closing spring 11. The drive cam 22 includes a cam profile 22a that is engaged in certain rotational positions by a drive roller 24 mounted on a main link 25, which is then pivotally connected to a drive arm 26 on a polar shaft 28 for closing the energy storage circuit breaker 1 when constrained by the tripping mechanism 30. The tripping mechanism 30 includes a hatchet 31 and a hatchet link (also called a banana link) 32, which is connected at one end to the hatchet 31 and pivotally connected at the other end to a roller pin 35. The axe-shaped member 31 includes a latching edge 31a that engages the trip D-shaft 33 (also referred to herein as a trip D-latch) when the trip D-shaft 33 is rotated to the latched position. With the axe-shaped member 31 latched, the axe-shaped link 32 holds the drive roller 24 engaged with the drive cam 22. In operation, the ETU 5 actuates the circuit breaker 1 to open by rotating the trip D-shaft 33 to the trip position, causing the latching edge 31a to slide off the trip D-shaft 33 and the axe-shaped member 31 to pass through a notch in the trip D-shaft 33. This repositions the pivot point of the axe-shaped link 32 connected to the axe-shaped member 31 and allows the drive roller 24 to float independently of the drive cam 22. Examples of air circuit breakers are further described in detail in U.S. Patents 6,437,269 and 6,066,821.

[0024] Figure 7The disconnect and release mode is shown, in which the closing spring 11 is released and contacts 15 and 16 are disconnected. In this position, the drive cam 22 is positioned such that the minimum radius of the energy storage cam 21 contacts the rocker arm roller 18. Therefore, the rocker arm 17 rotates to a fully clockwise position, and the closing spring 11 is at its maximum extension. Furthermore, the tripping mechanism 30 is not latched, allowing the drive roller 24 to float while resting against the drive cam 22. To store energy, the camshaft 23 is rotated counterclockwise manually via the handle 4 or by operation of the energy storage motor. As the camshaft 23 rotates, the diameter of the energy storage portion 21a of the energy storage cam 21 gradually increases, engaging the rocker arm roller 18, and causing the rocker arm 17 to rotate counterclockwise to compress the closing spring 11. Until the energy storage of the spring 11 is complete, the drive roller 24 contacts the portion of the drive cam 22 with a constant radius, allowing the drive roller 24 to continue floating. Figure 8 The disconnected and energy-storing position is shown, in which the closing spring 11 is fully energized and ready to close the separable contacts 15, 16. When the stop roller 40 is released via the close prop (not shown), the spring energy is released, causing the energy-storing cam 21 to rotate to the position in the closed and energy-release mode, as shown. Figure 9 As shown, when the energy storage cam 21 rotates by the spring force transmitted via the rocker arm 17, the drive roller 24 is engaged by the cam profile 22a of the second drive cam 22. The radius of the cam profile 22a increases as the camshaft rotates, and because the axe-shaped link 32 keeps the drive roller 24 in close contact with this surface, the polar axis 28 rotates to close the contacts 15, 16. At this time, the axe-shaped flange 31a engages the trip D-type latch 33, and the separable contacts 15, 16 are latched closed, i.e., in the fully closed position. If the air circuit breaker 1 trips at this time due to the rotation of the tripping D-shaft 33, causing the axe-shaped flange 31a to disengage from the axe-shaped D-shaft 33, then a very large force generated by the compression contact spring (not shown) exerted by the main connecting rod 25 will pull the pivot point of the axe-shaped connecting rod 32 on the axe-shaped member 31 downward, and the drive roller 24 will fall off the drive cam 24, thereby allowing the polar shaft 28 to rotate and allowing the contacts 15 and 16 to disconnect (return to the starting point). Figure 7 (The location where the energy release is disconnected is shown).

[0025] As mentioned earlier, the fully closed state is the position where the contact spring (not shown) is fully compressed and the air circuit breaker 1 will withstand the designed desired current. Identifying the moment when the circuit breaker mechanism reaches the fully closed state of the separable contacts 15, 16 is particularly important for accurately monitoring and / or diagnosing the health of the air circuit breaker 1. However, when the closing spring 11 is released, the contacts 15, 16 may touch but pause before reaching the fully closed position. Furthermore, due to factors such as, but not limited to, elasticity and friction, wear, environmental factors, etc., the position of the polar axis 28 may change during full closure. Therefore, identifying the fully closed state and determining the precise timing of full closure becomes difficult. Despite considerable efforts to determine the fully closed state and its precise timing, these efforts have been largely ineffective, and in fact, they are useless due to the variation in the closed position of the polar axis, which makes measuring the precise timing of the fully closed state virtually impossible. However, the exemplary novel device 100 solves these problems and allows for the identification of fully closed states and the precise timing of the opening and closing of contacts 15, 16 by using both the energy release detector 110 and the polar position detector 120. (Reference) Figures 10 to 12 Describe device 100.

[0026] Figure 10 A device 100 according to a non-limiting exemplary embodiment of the disclosed concept is shown. The device 100 is configured to control and / or monitor an air circuit breaker 1 and includes a holding device 101, a switching device monitor 102, an energy release detector 110, and a polar axis position detector 120. The holding device 101 is attached to a portion of the operating mechanism 10 including a closing spring 11, a cam assembly 20, a polar axis 28, and any associated linkage components thereof. Although... Figure 2 , Figures 4 to 6 as well as Figures 10 to 12The energy release detector 110 and polar position detector 120 are shown as microswitches, but this is for illustrative purposes only. Therefore, without departing from the scope of the disclosed concept, detectors 110 and 120 can be any type of suitable sensing device (e.g., but not limited to, switches, sensors, semiconductor devices including optocouplers). The switch device monitor 102 can be, for example, but not limited to, software or firmware configured to receive detection data from the energy release detector 110 and polar position detector 120, analyze the data, perform diagnostics, and send alarms to the user based on the diagnostics. Furthermore, the switch device monitor 102 is configured to perform control functions including MCR (current release) functionality without requiring a separate MCR device in the air circuit breaker 1. Based on the detection data input from each detector 110 and 120, the switch device monitor 102 is configured to determine the instantaneous state of the air circuit breaker 1. The switch device monitor 102 can be a standalone device for diagnostics and / or control, measuring timing (e.g., but not limited to, closing timing, overall speed, etc.) for performance-based device health monitoring. Figure 10 (As shown), or the switch monitoring device can be embedded, downloaded, or installed in another controller (such as ETU 5), such as Figure 3 As shown.

[0027] An energy release detector 110 is disposed adjacent to the energy storage cam 21 and configured to detect the fully released state of the closing spring 11. The energy release detector 110 includes a lever 111 configured to be actuated by the energy storage cam 21. A polar position detector 120 is disposed adjacent to the polar drive link 29 connected to the polar axis 28 and configured to detect the closure of contacts 15, 16. This polar position detector has a lever 121 configured to be actuated by the polar drive link 29 when the polar axis 28 reaches approximately the angle at which contacts 15, 16 first contact (when contacts 15, 16 touch but are not fully closed). Although Figure 13 Table 1 shows detectors 110 and 120, each including a switch, and switches 110 and 120 connected in parallel to one input of the switchgear monitor 102. However, it should be understood that this is for illustrative purposes only, and any other suitable scheme or mechanism may be used without departing from the scope of the disclosed concept. For example, detectors 110 and 120 may be independently wired to the switchgear monitor 102. In another example, switches 110 and 120 may have opposite states and be wired in series to one input of the monitor 102. In this alternative example, the air circuit breaker 1 is fully closed only when the detector circuit connected in series is closed.

[0028] In operation, the energy storage switch 60 is driven by a dedicated energy storage switch cam (not shown) connected to the cam assembly 20 of the energy storage cam 21, and this energy storage switch cam actuates the energy storage switch 60, thus bringing the device 100 to a fully charged state. The energy storage cam 21 has a profile including an energy storage portion 21a, which is substantially adjacent to the energy storage switch 60 when the device is fully charged. When the stop roller 40 is released, the cam assembly 20 rotates freely and releases energy from the closing spring 11. The drive roller 24 engages the drive cam 22, and as the camshaft 23 rotates, the radius of the drive cam 22 increases, causing the polar axis 28 to rotate and close the contacts 15, 16. During the closing of the contacts 15, 16, the energy storage cam 21 actuates the energy storage switch 60, which then begins to measure the contact closing time. When the contacts 15, 16 make their first contact (i.e., the first contact), the closing spring 11 does not release its energy to the maximum extent. Therefore, after the first contact, the closing spring 11 still stores energy to compress the contact spring. Furthermore, the polar position detector 120 is actuated upon the first contact. When the camshaft 23 has fully rotated (360°) and thus fully released energy, the circuit breaker 1 is fully capable of handling the design current, and contacts 15, 16 are now in the fully closed position. Therefore, the detection and precise timing of full closure are achieved through inputs from both the energy release detector 110 and the polar position detector 120 to the switchgear monitor 102.

[0029] If detectors 110 and 120 include switches and switches 110 and 120 are connected in parallel (e.g.) Figure 13 As shown in Table 1, the inputs from detectors 110 and 120 include, for example, but not limited to, binary outputs (0 and 1). A binary output of 0 indicates that the corresponding switch is open (in an open-circuit state), and a binary output of 1 indicates that the corresponding switch circuit is closed (in a closed-circuit state). For example, when the closing spring 11 is released by the rotation of the energy storage cam 21, the energy release detector 110 is in a closed-circuit state (1), and when the closing spring 11 is fully released and the energy storage cam 21 has completed its rotation, the energy release detector is in an open-circuit state (0). When the separable contacts 15 and 16 are disconnected via the polar axis 28, the polar axis position detector 120 is in a closed-circuit state (1), and when the separable contacts 15 and 16 are touched and / or fully closed via the polar axis 28, the polar axis position detector is in an open-circuit state (0).

[0030] In this exemplary embodiment, the switchgear monitor 102 receives an open input signal (0) indicating that the circuit breaker 1 has reached the fully closed state (fully closed position) only when both switches 110 and 120 are open. If one or both detectors 110 and 120 are closed, a closed input signal (1) is provided to indicate that the circuit breaker mechanism is not fully closed. Therefore, the switchgear monitor 102 determines that the fully closed state has been reached only when contacts 15 and 16 are fully closed and the closing spring 11 is fully released. This is important because the device 100 uses both detectors 110 and 120 simultaneously to accurately detect the fully closed state of the circuit breaker 1, which is not possible with existing closed state detectors or systems that only use polar axis position sensors. That is, when contacts 15 and 16 first touch, the drive roller 24 is still located on the radius-enlarged portion 22a of the drive cam 22 because the polar axis 28 still needs to travel further to compress the contact spring (not shown). This means that very high forces from contacts 15, 16 (such as electromagnetic forces that occur when a high current begins to flow) can, in some extreme cases, stop the closure or even reverse the direction of camshaft 23, thus potentially returning energy to the closing spring 11. Such a pause or reversal causes problems and is undesirable in some operating modes. Therefore, achieving a completely stable fully closed position is not considered possible until drive roller 24 reaches a constant radius portion of drive cam 22 (which coincides with the full release of the closing spring). Therefore, using polar position detector 120 alone as an existing closure state detector or system cannot provide accurate detection of the fully closed state. Furthermore, utilizing two detectors 110, 120 avoids any problems that would arise from using only release detector 110. This is because cam assembly 20 and camshaft 23 may be in the same fully released position before the air circuit breaker 1 trips and after the circuit breaker 1 trips via release trip mechanism 30 (e.g., tripping D-type latch 33). Therefore, the release detector 110 alone cannot accurately detect the fully closed state of the circuit breaker 1 because it cannot distinguish whether the circuit breaker 1 is in a fully closed state or an open and release state. By using a polar position detector 120 in addition to the release detector 110, the device 100 can identify the difference between the fully closed state and the open and release state when the release detector 110 detects that the cam assembly 20 / camshaft 23 is in the fully release position.

[0031] Therefore, under the disclosed concept, the fully closed state is defined and detected as the state where the polar axis 28 has passed the contact contact point and the camshaft 23 has rotated far enough to position the roller 24 on a constant radius segment of the drive cam 22. By detecting the fully closed state and the precise timing of achieving the fully closed state, the device 100 provides precise monitoring of the state of the air circuit breaker 1. For example, the precise moment of achieving the fully closed state (when the camshaft 23 reaches the angle of full release and the drive roller 24 is on a constant radius) provides a useful, precisely defined endpoint for closing time measurements for device health and diagnostics. Furthermore, achieving the fully closed state provides useful confirmation of successfully reaching a stable position capable of withstanding the full design current level. Therefore, if the circuit breaker 1 does not achieve the fully closed state within the expected time interval, it can be expected that the circuit breaker mechanism may stall and will not be able to achieve full current withstand capability. In this case, the ETU 5 may need to initiate circuit breaker disconnection (release tripping mechanism 30) to return to the safe disconnect position to avoid undesirable consequences.

[0032] Return to the attached diagram for reference. Figure 13 Four states of the air circuit breaker 1 are shown, where detectors 110 and 120 are switches connected in parallel. In the open and energy-storing state 130, the polar position detector 120 is in the closed state (1), and the energy-releasing detector 110 is in the open state (0). In this state, contacts 15 and 16 are open and the closing spring 11 stores energy. In the early closed state 131, the polar position detector 120 is in the closed state (1), and the energy-releasing detector 110 is also in the closed state (1). Therefore, contacts 15 and 16 are closed and the closing spring 11 releases energy. In the late closed state 132, the polar position detector 120 is in the open state (0), and the energy-releasing detector 110 is in the closed state (1). In this state, the first contact has occurred, so the polar position detector 120 is now open. In addition, the closing spring 11 is releasing energy but still stores energy. Therefore, the energy-releasing detector 110 remains closed. In the fully closed state 133, the polar axis detector 120 is in the open circuit state (0), and the energy release detector 110 is in the open circuit state (0). In this state, the current release (MCR) circuit (not shown) is disconnected. Furthermore, since the camshaft 23 has completed its 360° rotation and the closing spring 11 has been fully released, the polar axis position detection 120 remains disconnected, and the energy release detector 110 is now also disconnected.

[0033] Table 1 shows the following... Figure 13The circuit breaker 1 is shown in four states. In the open and energy-storing state, the polar position detector 120 and the energy release detector 110 provide input signals 1 and 0 to the switchgear monitor 102, respectively. The switchgear monitor 102 then returns a logic result of 1, indicating that the circuit breaker mechanism is open. In the early closing state, the polar position detector 120 and the energy release detector 110 provide input signals 1 and 1 to the switchgear monitor 102, respectively. The switchgear monitor 102 then returns a logic result of 1, indicating that the circuit breaker mechanism is not fully closed. In the late closing state, the polar position detector 120 and the energy release detector 110 provide input signals 0 and 1 to the switchgear monitor 102, respectively. The switchgear monitor 102 then returns a logic result of 1, indicating that the circuit breaker mechanism is not fully closed. Finally, when the circuit breaker mechanism has reached the fully closed state, the polar position detector 120 and the energy release detector 110 provide input signals 0 and 0 to the switchgear monitor 102, respectively. Only at this point will the switchgear monitor 102 return a logic result of 0, indicating that the circuit breaker mechanism is fully closed.

[0034] Table 1

[0035]

[0036] Therefore, as mentioned above, by utilizing both the polar position detector 120 and the energy release detector 110, the exemplary device 100 of the disclosed concept identifies the discrete fully closed states of the air circuit breaker 1 and the precise timing of reaching the fully closed state, which differs from existing closed position detectors or systems that cannot provide either the identification of discrete fully closed positions or the precise timing of the circuit breaker's full closure. Thus, the switchgear monitor 102 can analyze the input data from the detectors 110, 120 and provide an accurate and reliable diagnosis of the health status of the air circuit breaker 1. For example, if the manufacturer's specifications indicate an acceptable closing time to reach the fully closed position as, for example, but not limited to, 29 ms, but the measured closing time is, for example, but not limited to, 35 ms, the switchgear monitor 102 can determine that the air circuit breaker 1 needs inspection and send an alarm to the user stating that the measured closing time is slower than a reference threshold (e.g., but not limited to, 33 ms) and that maintenance of the air circuit breaker 1 is required. In another instance, if there is a trend of gradually increasing closing time based on precise closing times measured over a period of time (e.g., but not limited to 6 months, 1 year, etc.), the switchgear monitor 102 can determine that the air circuit breaker 1 may have wear or damage, and warn the user of this trend and recommend further inspection. This continuous, real-time, and customized monitoring of the complete closing status of each air circuit breaker without interrupting power distribution allows the user to schedule maintenance and inspections as needed, and to perform remedial measures when necessary.

[0037] Additionally, device 100 can be configured to facilitate the detection and identification of fault modes. For example, with detectors 110 and 120 wired as two separate inputs to switch monitor 102, the input from each detector 110 and 120 can be used to detect and identify fault modes. Fault modes include, but are not limited to, fire-through, shock-out, and incomplete closure. Fire-through is the release of spring energy without closing the air circuit breaker 1. In this case, the energy release detector 110 will return 0, but the polar position detector 120 will return 1, indicating the presence of a fire-through fault mode. Shock-out is the immediate opening after closing. That is, after the first contact, the air circuit breaker 1 will immediately begin to open within microseconds. In this case, both detectors 110 and 120 return 0 momentarily (microseconds). If the 0 input from detectors 110 and 120 lasts only microseconds, it can be inferred that a shock-out fault mode has occurred. Incomplete closure is the situation where the circuit breaker 1 is not fully closed. In other words, detectors 110 and 120 do not return a zero input within the threshold closing time. Detecting and alarming the fault mode when it occurs allows the user to take timely corrective action. It should be noted that the example fault modes are provided for illustrative purposes only, and therefore, the device 100 may appropriately detect other fault modes without departing from the scope of the disclosed concept.

[0038] Furthermore, the device 100 can perform MCR (current release) based on inputs from detectors 110 and 120 without requiring a separate MCR device to be installed in the air circuit breaker 1, thereby reducing manufacturing time and cost.

[0039] While specific embodiments of the invention have been described in detail, those skilled in the art will understand that various modifications and alternatives to those details can be developed in light of the general teachings of this disclosure. Therefore, the specific arrangements disclosed are intended to be illustrative only and do not limit the scope of the disclosed concept, which will be given by the full breadth of the appended claims and any and all equivalents thereof.

Claims

1. A device for use in an electrical switching apparatus, the electrical switching apparatus including an operating mechanism having an energy storage device, a cam assembly, a polar shaft coupled to the cam assembly, and a separable contact coupled to the polar shaft, the device comprising: A holding device configured to be attached to the operating mechanism of the electrical switching device; An energy release detector is attached to the holding device and configured to be disposed adjacent to the cam assembly, and detects the energy release state of the energy storage device based on the position of the cam assembly; A polar position detector is attached to the holding device and configured to be coupled to the polar axis, and detects the open and closed state of the separable contact based on the position of the polar axis; as well as A switching device monitor is connected to the energy release detector and the polar position detector. The switching device monitor is configured to receive data from these detectors, analyze the data, and perform control and / or diagnostics on the electrical switching device based on the analysis. The data includes the detected energy release state of the energy storage device and the detected open and closed states of the separable contacts.

2. The device according to claim 1, wherein, The energy release detector is also configured to measure the timing of contact closure, and the data includes the measured timing.

3. The device according to claim 2, wherein, The switch device monitor is also configured to identify the fully closed state of the separable contact and to measure the precise timing of reaching the fully closed state based on the data.

4. The device according to claim 1, wherein, The cam assembly includes an energy storage cam and a drive cam, wherein the energy release detector is actuated by rotation of the energy storage cam, and the polar position detector is actuated by the polar axis.

5. The device according to claim 4, wherein, The energy release detector and the polar axis position detector are switches connected in parallel, wherein the energy release detector is closed when the energy storage device is releasing energy through the rotation of the energy storage cam, and is open when the energy storage device has fully released energy and the energy storage cam has completed its rotation, and wherein the polar axis position detector is closed when the separable contact is disconnected via the polar axis, and is open when the separable contact is touched and / or fully closed via the polar axis.

6. The device according to claim 5, wherein: When the electrical switching device is open and in the energy storage state, the polar axis position detector is closed and the energy release detector is open; In the early closed state of the electrical switching device, the polar axis position detector is closed, and the energy release detector is closed; In the later closed state of the electrical switching device, the polar position detector is open and the energy release detector is closed; or When the electrical switching device is fully closed, the polar position detector is disconnected and the energy release detector is disconnected.

7. The device according to claim 1, wherein, The device is also configured to perform a current release function.

8. The device according to claim 1, wherein, The switch monitoring device is also configured to warn the user and recommend preventative measures based on the analysis of the data.

9. The device according to claim 1, wherein, The switch device monitor is also configured to determine a fault mode based on the data and warn the user of the fault mode.

10. The device according to claim 1, wherein, The switch device monitor is located within the electronic tripping unit of the electrical switch device.

11. The device according to claim 1, wherein, The energy storage device includes a spring.

12. An electrical switching device configured to connect a power source and a load, comprising: case; Energy storage components; An electrical trip unit is configured to interrupt the current flowing to the load in the event of an abnormal current. An operating mechanism is connected to the energy storage component and the electrical trip unit. The operating mechanism includes an energy storage device, a cam assembly, a polar shaft connected to the cam assembly, and a separable contact. The separable contact has a movable contact connected to the load and a fixed contact connected to the power supply. as well as A device configured to monitor the state of the electrical switching device, the device comprising: A holding device configured to be attached to the operating mechanism of the electrical switching device; An energy release detector is attached to the holding device and configured to be disposed adjacent to the cam assembly, and detects the energy release state of the energy storage device based on the position of the cam assembly; A polar position detector, attached to the holding device and configured to be coupled to the polar axis, detects the open and closed states of the separable contact based on the position of the polar axis; and A switching device monitor, disposed within the electrical trip unit and connected to the energy release detector and the polar axis position detector, is configured to receive data from these detectors, analyze the data, and perform control and / or health diagnostics on the electrical switching device based on the analysis. The data includes the detected energy release status of the energy storage device and the detected open and closed states of the separable contacts.

13. The electrical switching device according to claim 12, wherein, Both the energy release detector and the polar position detector include microswitches, sensors, or semiconductor devices including optocouplers.

14. A method for protecting an electrical switching device, the electrical switching device comprising an operating mechanism having an energy storage device, a cam assembly, a polar shaft coupled to the cam assembly, and a separable contact coupled to the polar shaft, the method comprising: The energy release state of the energy storage device is detected based on the position of the cam assembly. The open and closed states of the separable contact are detected based on the position of the polar axis; as well as The data analyzed includes the detected energy release state of the energy storage device and the detected open and closed states of the separable contacts.

15. The method according to claim 14, further comprising: The electrical switching device is then diagnosed based on the analysis.

16. The method according to claim 15, further comprising: The timing of contact closure is measured, wherein the data includes the measured timing.

17. The method according to claim 16, further comprising: Identify the fully closed state of the separable contact; as well as The precise timing for achieving the fully closed state is measured based on the data.

18. The method according to claim 14, wherein, The energy release detector and the polar axis position detector are switches connected in parallel, wherein the energy release detector is closed when the energy storage device releases energy through the rotation of the energy storage cam, and is open when the energy storage device has fully released energy and the energy storage cam has completed its rotation, and wherein the polar axis position detector is closed when the separable contact is disconnected via the polar axis, and is open when the separable contact is touched and / or fully closed via the polar axis.

19. The method of claim 18, wherein: When the electrical switching device is open and in the energy storage state, the polar axis position detector is closed and the energy release detector is open; In the early closed state of the electrical switching device, the polar axis position detector is closed, and the energy release detector is closed; In the later closed state of the electrical switching device, the polar position detector is open and the energy release detector is closed; or When the electrical switching device is fully closed, the polar position detector is disconnected and the energy release detector is disconnected.

20. The method of claim 14, further comprising: The current release function is performed based on the analysis.

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