Continuously monitored remote power turn-off
By combining monitoring circuits and a notification system, the reliability and cost issues of remote power shutdown technology in emergency situations are resolved, achieving highly reliable and low-complexity remote power shutdown while reducing hardware and power requirements.
Patent Information
- Application Number
- CN202511236122.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2019-08-20
- Filing Date
- 2020-07-08
- Publication Date
- 2026-01-23
AI Technical Summary
Existing remote power shutdown technologies suffer from problems such as system unavailability in emergency situations, failure to remove power during faults, incomplete monitoring of some circuits, high operating and hardware costs. In particular, continuous power supply circuits cause temporary power loss, and non-continuous power supply circuits cannot respond in time during faults.
The monitoring circuit continuously monitors the circuit integrity of the power removal circuit and generates automated notifications through the notification system. Combined with the tripping device for non-continuous power supply, it ensures timely response and maintains equipment operation in the event of a fault, reducing hardware and power requirements.
It enables highly reliable remote power shutdown in emergency situations, reducing hardware and power requirements, avoiding equipment downtime caused by brief power loss, and lowering costs and complexity.
Smart Images
Figure CN121395718A_ABST
Abstract
Description
[0001] This application is a divisional application. The parent application has the title “Continuously Monitored Remote Power Off” and has a filing date of July 8, 2020, and application number 202080058526.9.
[0002] Cross Reference to Related Applications This application claims the benefit of U.S. Provisional Application No. 62 / 889,243, filed August 20, 2019, which is incorporated by reference herein in its entirety. TECHNICAL FIELD
[0003] The present disclosure relates generally to power management, and more particularly to continuously monitored remote power off. BACKGROUND
[0004] Remote power off (also known as emergency power off or EPO) is typically provided as a safety measure to quickly disconnect power to a particular piece of equipment (e.g., a diagnostic image scanner) in the event of an emergency situation. Such an emergency situation can occur in an immediate danger situation that needs to be quickly ended or avoided in order to prevent injury or damage. A remote actuator (e.g., remote power off or RPO, emergency power off or EPO) can be used to facilitate the remote removal of power and allow all power to be safely turned off from a central location.
[0005] Remote power off can be implemented using either a continuously powered circuit or a non-continuously powered circuit. A continuously powered circuit requires continuous energization of the trip device. Unfortunately, this results in system shutdown during brief power loss and results in an inoperable device or system in the presence of a circuit fault. Additionally, such a design can require additional hardware and cost that needs to be added to maintain power on. Higher power circuits require additional current draw to maintain power to the device. Increasingly larger components and multi-phase systems are also required, which increases additional hardware requirements and hardware and operating costs.
[0006] On the other hand, a non-continuously powered circuit only applies power to the trip device during activation to remove power to the device. While this solution allows the device to continue operating during a circuit fault (e.g., disconnection due to wire breakage or coil burnout), the circuit fault is not known until the emergency shutdown needs to operate. This results in a failure to remove power during an emergency situation, causing a dangerous situation. Operational verification requires additional costs for testing, device downtime, and personnel. SUMMARY
[0007] A framework for continuously monitored remote power shutdown is described herein. According to one aspect, a monitoring circuit is coupled to a power removal circuit. The monitoring circuit can generate an output signal indicative of circuit integrity based on one or more electrical characteristics of the power removal circuit. A notification system can be further coupled to the monitoring circuit. The notification system can generate a notification based on the output signal. BRIEF DESCRIPTION OF DRAWINGS
[0008] A more complete appreciation of the present disclosure and its many attendant aspects will be readily obtained by reference to the following detailed description, when considered in connection with the accompanying drawings.
[0009] Figure 1 An example remote power shutdown system is shown; Figure 2 Another example remote power shutdown system is shown; and Figure 3 An example method of continuously monitoring remote power shutdown is shown. DETAILED DESCRIPTION
[0010] In the following description, numerous specific details are set forth such as examples of specific components, devices, methods, etc., in order to provide a thorough understanding of implementations of the present framework. It will be apparent, however, to one skilled in the art that these specific details need not be employed to practice the present framework. In other instances, well-known materials or methods have not been described in detail in order to avoid unnecessarily obscuring the present framework. Accordingly, the specific embodiments of the present framework that have been described are illustrative in nature and are not intended to limit the scope of the application, as it will be appreciated that various modifications can be made and equivalents employed by those skilled in the art. Furthermore, there is no intention that the use of the specific extreme values represent the narrowest values of the range that can be claimed. Additionally, for ease of understanding, certain method steps are depicted as separate steps; however, such separately depicted steps should not be construed as necessarily dependent on the order in which they are performed.
[0011] A framework for continuously monitored remote power shutdown is described herein. According to one aspect, a monitoring circuit is coupled to a power removal circuit. The monitoring circuit can generate an output signal indicative of circuit integrity based on one or more electrical characteristics of the power removal circuit. A notification system can be further coupled to the monitoring circuit. The notification system can generate a notification based on the output signal.
[0012] The framework advantageously provides power removal even in the event of a faulty power removal circuit. Additionally, the framework continuously monitors all elements in the power removal circuit, including the elements described herein (e.g., the trip device) as well as any additional elements not described herein. Notification of any circuit failure or condition can be immediately issued. The framework can ride through a brief power loss, allowing the power removal circuit to remain operational to achieve an emergency power shutdown. Advantageously, there is no nuisance tripping during a brief power loss. Moreover, minimal hardware is required and minimal additional power is required to implement the framework. Furthermore, high reliability of the remote power shutdown function is achieved. These and other exemplary features and advantages will be described herein.
[0013] Figure 1 An exemplary remote power shutdown system 100 is shown. The remote power shutdown system 100 is coupled to a powered device (or system) 103. The device 103 receives three-phase system power via power lines A, B, and C. It should be appreciated that although the remote power shutdown system 100 is shown as a three-phase alternating current (AC) circuit, the framework is also applicable to other types of circuits, including but not limited to single-phase, two-phase, split-phase, direct current (DC), or combinations thereof.
[0014] The device 103 can be any powered system that can require power removal or electronic stopping in, for example, an emergency event. For example, the device 103 can be an industrial vulcanizer, an industrial furnace, or an elevator. The device 103 can also be a medical imaging modality that acquires medical image data. Such a medical imaging modality can be a radiology or nuclear medicine imaging scanner. Such a medical imaging modality can acquire medical image data by magnetic resonance (MR) imaging, computed tomography (CT), spiral CT, x-ray, positron emission tomography (PET), PET-CT, fluoroscopy, ultrasound, or single photon emission computed tomography (SPECT). Other types of imaging modalities or devices can also be used.
[0015] In some implementations, the remote power shutdown system 100 includes a power removal circuit 101 coupled to a monitoring circuit 107. The power removal circuit 101 enables remote triggering of a power shutdown of the powered device 103. In some implementations, the power removal circuit 101 includes a disconnect switch (or circuit breaker) 102 and an actuator 104 coupled to a trip device 106. When the actuator 104 is activated, control power becomes available to the trip device 106 and activates the trip device 106, which then activates the disconnect switch 102 (e.g., opens the contacts), removing system power to the device 103. Although Figure 1A single actuator 104 and a single trip device 106 are illustrated, but it should be appreciated that multiple instances of each of them can be provided. Additionally, one or more elements other than those depicted can be provided. Figure 1
[0016] The disconnect switch 102 can include, but is not limited to, a power disconnect switch, a circuit breaker, contacts of a contactor, a relay, or a combination thereof. The actuator 104 can be, for example, a remote actuator such as an RPO or EPO button. The actuator 104 can include one or more actuator contacts (e.g., relay contacts, contactor contacts, circuit breaker auxiliary contacts), a solid state transistor based switch, or a combination thereof. For example, the actuator 104 can include a relay having a normally open (NO) contact actuated by a series of normally closed (NC) contacts in an RPO station.
[0017] The trip device 106 can include at least one electromagnetic coil that is non- persistently powered by control power lines 1 and 2 (LI, L2). Control power is applied to the trip device 106 only when the actuator 104 is activated. When the actuator 104 is activated by control power, the trip device 106 receives control power and actuates (or applies control power to) the disconnect switch 102 to remove system power to the equipment 103. Advantageously, because the trip device 106 is non-persistently powered, a brief power loss does not actuate the disconnect switch 102. The equipment 103 can ride through the brief power loss and remain operational during the brief power loss.
[0018] The trip device 106 can include, but is not limited to, a shunt trip, an electric circuit breaker, a contactor, a power shutdown circuit of an uninterruptible power supply (UPS), an under-voltage trip (UVT) circuit, or a combination thereof. It should be appreciated that control power can be any type of power, such as alternating current (AC) power, direct current (DC) power, single phase power, multi-phase power, or a combination thereof. The power can include any frequency or voltage level with appropriate selection of the component(s) of the monitoring circuit 107.
[0019] The monitoring circuit 107 is coupled to the actuator 104 to continuously monitor the power removal circuit 101 and provide an output signal that can indicate circuit integrity (or continuity). The monitoring circuit 107 advantageously enables the device 103 to remain operational in a fault event in the power removal circuit 101 while providing high reliability of the power shutdown function in an emergency event. In some implementations, the monitoring circuit 107 is coupled across the normally open contacts of the actuator 104 to provide an indication of circuit integrity. Circuit integrity generally refers to the operability of the power removal circuit 101 during activation of the actuator 104 in an emergency event, e.g., requiring a power shutdown of the device 103. Circuit integrity can be affected by, e.g., a line break, and coil integrity and / or coil burnout in the trip device 106.
[0020] The monitoring circuit 107 generates an output signal indicating circuit integrity based on one or more electrical characteristics of the power removal circuit 101. The output signal can be, e.g., a discrete signal representing a circuit state of the power removal circuit 101. For example, when the output signal is "off" (or at a predetermined low level), it can indicate a fault state. When the output signal is "on" (or at a predetermined high level), it can indicate an operable state or a normal state. The electrical characteristics of the power removal circuit 101 can include, but are not limited to, a closed loop current, a closed loop voltage, a frequency, or a combination thereof.
[0021] In some implementations, the monitoring circuit 107 includes a high impedance (or low current) device 108 to generate the output signal. The high impedance device 108 can include, but is not limited to, a high impedance switch, a relay, an optical isolator, or a combination thereof. For example, the high impedance device 108 is a solid state relay with optical isolation. The high impedance device 108 can be de-energized in response to a fault occurring in the power removal circuit 101, thereby producing a low output signal that is provided to the notification system 110.
[0022] The monitoring circuit 107 is coupled to the notification system 110 to automatically generate a notification 112 based on the output signal. The notification system 110 can be a computer system, an alarm circuit, or any other system capable of generating a notification 112 based on the output signal. The notification system 110 can be coupled to the high impedance device 108 to receive the output signal. The notification 112 can notify a user (or system) of a status of the power removal circuit 101 (e.g., a fault state or an operable state). The notification 112 can include, e.g., a visual alarm, an audible alarm, an electronic text message, an email message, or a combination thereof. The notification 112 can also be transmitted to a monitoring system (not shown) associated with the powered device 103 to perform one or more actions in response to the notification 112.
[0023] Advantageously, circuit failure throughout the power removal circuit 101 can be continuously and automatically monitored by the monitoring circuit 107. The user (or system) can be immediately notified of a failure condition in the power removal circuit 101 so that action can be taken to correct the failure. The circuit 100 advantageously requires minimal hardware, thereby reducing cost, size, and installation effort. Additionally, minimal additional power is required. High reliability of the remote power shutdown function is achieved in emergency event.
[0024] Figure 2 Another example remote power shutdown system 200 is shown. The remote power shutdown system 200 is coupled to a powered device 103. The remote power shutdown system 200 includes a power removal circuit 101 coupled to a monitoring circuit 207. The power removal circuit 101 enables remote triggering of a power shutdown of the powered device 103. In some implementations, the power removal circuit 101 includes a disconnect switch (or circuit breaker) 102 and an actuator 104 coupled to a trip device 106. When the contacts in the actuator 104 are closed, current becomes available to the trip device 106, which then causes the contacts in the disconnect switch 102 to open, thereby removing system power to the device 103.
[0025] The monitoring circuit 207 is coupled to the actuator 104 to continuously monitor the circuit 101 and provide an output signal indicative of the overall circuit integrity (or continuity) based on one or more electrical characteristics of the power removal circuit 101. In some implementations, the monitoring circuit 207 is coupled across the normally open contacts of the actuator 104 to provide the circuit integrity indication. The monitoring circuit 207 can include a high impedance (or low current) device 210 and a current transformer 212 coupled across the actuator 104. The high impedance (or low current) device 210 can include, for example, a current limiting resistor, a relay coil, or a combination thereof. A current meter 214 can be coupled across the current transformer 212 for measuring current and generating an output signal. The output signal of the current meter 214 is indicative of the circuit integrity (or circuit status) of the power removal circuit 101. Thus, the monitoring circuit 207 continuously and automatically monitors the power removal circuit 101 (e.g., the trip device 106) and provides verification of the circuit integrity while allowing the powered device 103 to remain operational in a circuit failure event and providing high reliability of the power shutdown function in an emergency event.
[0026] The monitoring circuit 207 is coupled to the notification system 110 to provide automatic user notification 112 of the circuit fault. The notification system 110 can be coupled to the ammeter 214 to receive its output and generate a user notification 112 based on the output signal. The output signal can be, for example, a discrete signal that represents a circuit fault state when "off" (or a predetermined low level) and represents an operable circuit state when "on" (or a predetermined high level). The output signal can be monitored by the notification system 110, which reports the notification 112 to the user. The user notification 112 can include, for example, a visual alarm, an audible alarm, an electronic text message, an email message, or a combination thereof.
[0027] Figure 3 An exemplary method 300 of continuously monitoring for remote power shutdown is shown. It should be understood that the steps of the method 300 can be performed in the order shown or in a different order. Additional, different, or fewer steps can also be provided. Moreover, the method 300 can be implemented with the system 100 of Figure 1 the system 200 of Figure 2 a different system, or a combination thereof.
[0028] At 302, the shutdown switch 102 is deactivated, and the actuator 104 is also deactivated. At 304, system power and control power are applied to the remote power shutdown system (100 or 200). The device 103 receives the system power via the deactivated (e.g., closed) shutdown switch 102. At 306, if there is no fault present in the power removal circuit 101, the method 300 proceeds to 332. If there is a fault, the method 300 proceeds to 308.
[0029] At 308, the monitoring circuit (107 or 207) generates a first predetermined level of the output signal based on one or more electrical characteristics of the power removal circuit 101. For example, the high impedance device 108 can change the state from a high output signal to a low output signal in response to the occurrence of a fault. At 310, the notification system 110 is activated in response to the first predetermined level of the output signal. At 312, in response to the activation, the notification system 110 generates the notification 112 indicating the fault state of the power removal circuit 101. During this fault event, the trip device 106 is deactivated, and the shutdown switch 102 remains deactivated (e.g., closed), allowing system power to pass to the device 103. Thus, the device 103 remains powered and operational, and does not shut down with the power removal circuit 101.
[0030] If no emergency event occurs, the method 300 can continue from 312 directly to 326. However, if an emergency event occurs at 321, the device 103 needs to be shut down. At 322, system power is removed from the device 103 by activating the kill switch 102 instead of remotely activating the actuator 104 of the power removal circuit 101. At 324, in response to activation of the kill switch 102, system power is removed from the device 103 and the device 103 is shut down. The fault in the power removal circuit 101 can be repaired during this emergency event.
[0031] At 326, the fault in the power removal circuit 101 is repaired and, thus, the power removal circuit 101 is fully functional. At 328, the kill switch 102 and the actuator 104 are deactivated. At 330, system power and control power are applied to the remote power shutdown system (100 and 200). System power is then delivered to the device 103.
[0032] At 332, when there is no fault in the power removal circuit 101 or the previous fault has been repaired, a second predetermined level of the output signal is generated based on one or more electrical characteristics of the power removal circuit 101. For example, the high impedance device 108 can be activated and a high output signal is sent to the notification system 110 indicating that the power removal circuit 101 is operational. At 334, in response to the second predetermined level of the output signal, the notification system 110 is deactivated. At 336, in response to the deactivation, the notification system 110 can send a notification 112 indicating that the remote power shutdown system is operational (i.e., an operational or normal state). Although there is no fault in the power removal circuit 101, the trip device 106 is not powered when the actuator 104 is deactivated. The kill switch 102 is thereby deactivated (e.g., closed), allowing system power to be delivered to the device 103. The device 103 remains powered and operational. The trip device 106 can allow a small current to flow that powers the high impedance monitoring device 108 but does not actuate the kill switch 102.
[0033] At 343, an emergency event occurs that requires the device 103 to be turned off. At 344, because there is no fault in the power removal circuit 101, the user (or external device) can use the actuator 104 to remove system power from the device 103. At 348, the notification system 110 is activated in response to, for example, deactivation of the high impedance device 108 (e.g., removal of control power). At 350, the notification system 110 sends a notification 112 indicating that the actuator 104 is activated in response to receiving a low output signal from, for example, the high impedance device 108. During the emergency event, the trip device 106 can receive control power and be activated, thereby activating (e.g., opening) the shutdown switch 102. At 352, the device 103 no longer receives system power and is successfully turned off.
[0034] While the present framework has been described with reference to exemplary embodiments, it will be apparent to those of ordinary skill in the art that various modifications and substitutions can be made thereto without departing from the spirit and scope of the application as set forth in the following claims. For example, elements and / or features of different illustrative embodiments can be combined and / or substituted for each other within the scope of the present disclosure and the following claims.
Claims
1. A system comprising: a monitoring circuit coupled to a power removal circuit, wherein the monitoring circuit generates an output signal indicative of circuit integrity based on one or more electrical characteristics of the power removal circuit, wherein the power removal circuit comprises a disconnect switch, an actuator, and a tripping device, wherein the tripping device is powered by control power only when the actuator is activated and activates the disconnect switch to remove system power to a device in response to the activation, wherein the monitoring circuit comprises a high impedance device and a current transformer coupled across the actuator in the power removal circuit, and a current meter coupled across the current transformer to generate the output signal; and a notification system coupled to the monitoring circuit to receive the output signal, wherein the notification system generates a notification based on the output signal.
2. The system of claim 1, wherein the one or more electrical characteristics comprise a closed loop current, a closed loop voltage, a frequency, or a combination thereof.
3. The system of claim 1, wherein the high impedance device is deactivated in response to a fault occurring in the power removal circuit.
4. The system of claim 1, wherein the high impedance device comprises a high impedance switch, a relay, an optical isolator, or a combination thereof.
5. The system of claim 1, wherein the notification system is coupled to the high impedance device to receive the output signal.
6. The system of claim 1, wherein the output signal is a discrete signal representative of a circuit state.
7. The system of claim 1, wherein the notification comprises a visual alert, an audible alert, an electronic text message, an email message, or a combination thereof.
8. The system of claim 1, further comprising the power removal circuit coupled to the device, wherein the power removal circuit enables a remote trigger of a power shutdown of the device.
9. The system of claim 1, wherein the disconnect switch comprises a power disconnect switch, a circuit breaker, a contact of a contactor, a relay, or a combination thereof.
10. The system of claim 1, wherein the actuator comprises an actuator contact, a solid state transistor based switch, or a combination thereof.
11. The system of claim 1, wherein the tripping device comprises a shunt trip, an electrically operated circuit breaker, a contactor, a power shutdown circuit of an uninterruptible power supply (UPS), an under voltage trip (UVT) circuit, or a combination thereof.
12. A method comprising: generating, by a monitoring circuit, an output signal based on one or more electrical characteristics of a power removal circuit coupled to a device, wherein the power removal circuit comprises a disconnect switch, an actuator, and a tripping device, wherein the tripping device is powered by control power only when the actuator is activated and activates the disconnect switch to remove system power to the device in response to the activation, wherein the monitoring circuit comprises a high impedance device and a current transformer coupled across the actuator in the power removal circuit, and a current meter coupled across the current transformer to generate the output signal; and in response to a fault in the power removal circuit, generating a notification of a fault state based on the output signal while deactivating the tripping device to allow the system power to pass to the device. 13. The method of claim 12, further comprising: removing the system power from the device by activating a cutoff switch in the power removal circuit in response to a fault in the power removal circuit and an emergency event.
14. The method of claim 12, further comprising: generating a notification of an operable status based on the output signal in response to no fault in the power removal circuit.
15. The method of claim 12, further comprising: removing the system power from the device by remotely activating an actuator in the power removal circuit in response to no fault in the power removal circuit and an emergency event.
16. A method comprising: continuously monitoring a power removal circuit by generating, by a monitoring circuit, an output signal indicative of circuit integrity based on one or more electrical characteristics of the power removal circuit, wherein the power removal circuit comprises a cutoff switch, an actuator, and a tripping device, wherein the tripping device is powered by a control power only when the actuator is activated and activates the cutoff switch to remove system power to a device in response to the activation, wherein the monitoring circuit comprises a high impedance device and a current transformer coupled across the actuator in the power removal circuit, and a current meter coupled across the current transformer to generate the output signal; and generating a notification based on the output signal.
17. The method of claim 16, further comprising: removing the system power from the device by activating a cutoff switch in the power removal circuit in response to a fault in the power removal circuit and an emergency event.
18. The method of claim 16, further comprising: generating a notification of an operable status based on the output signal in response to no fault in the power removal circuit.
19. The method of claim 16, further comprising: removing the system power from the device by remotely activating an actuator in the power removal circuit in response to no fault in the power removal circuit and an emergency event.