MX2008008070A - System for wireless communications among plural electrical distribution devices of an electrical distribution enclosure - Google Patents

Abstract

An electrical distribution system includes a switchgear or motor control center cabinet, a plurality of first protective, metering or control devices internal to the cabinet, and one or more second devices. The second devices include display devices mounted on the cabinet, display devices external to the cabinet and monitoring devices structured to monitor the system and communicate to a remote location. Communications among the first devices and the second devices are wireless communications.

Description

SYSTEM FOR WIRELESS COMMUNICATIONS BETWEEN ELECTRICAL DISTRIBUTION DEVICES AN ACCOMMODATION OF ELECTRICAL DISTRIBUTION Background of the Invention Field of the Invention This invention relates generally to electrical distribution systems and, more particularly, to such systems providing communications between electrical distribution devices of an electrical distribution housing. BACKGROUND INFORMATION An electrical distribution system typically consists of a plurality of protective, metering and control devices mounted within a housing, such as a control mechanism or central motor control cabinet or suitable plastic housing. A wired communication mechanism is often provided which allows the various devices to communicate with a deployment device in the housing or to communicate to a remote location, which monitors the condition of the system. The wired communication mechanism within the housing typically employs one or more wired field bus bars. Electrical distribution devices, such as circuit breakers, are installed inside the cabinet metal control mechanism. Many of these devices are capable of communicating, for example, online data, and alarm / status information, triggering cause and fi x point. Typically, wired field bus bars are "twisted pair" bus bars that connect the devices to a single node associated with the distribution device enclosure. There are numerous versions of that node including: (1) local nodes with a human machine interface (HMI) (eg, screens and switches) intended for use in the cabinet; (2) nodes that are "headless" and serve as interfaces or gates to connect the devices to one or more remote communication systems; and (3) nodes that serve both local and remote functions. Figure 1 shows an electrical distribution device 2 that includes a twisted pair field bus network 4 and a "headless" node 6 that interfaces with field busbar communication devices in mesh, such as 7, 8, 9, 10, and an Ethernet communications system 12. There is room for improvement in communications in electrical distribution systems. SUMMARY OF THE INVENTION This need and others are met by the present invention which provides a system for wireless communications between electrical distribution devices of a - J -accommodation of electrical distribution. According to one aspect of the invention, an electrical distribution system comprises: a housing; a plurality of first devices internal to the housing, the first devices being protective, measuring or control devices; and at least a second device, the at least one second device being mounted in the housing, being external to the housing or being structured to monitor the system and communicate with a remote location, where communications between the first devices and the at least a second device is wireless communications. Wireless communications can be radio frequency communications. Radio frequency communications can be provided over a mesh network, a star network or a star-mesh network. The at least one second device can be a portable wireless communications device. The at least one second device can be a deployment or operator interface which is mounted externally to the housing. The at least one second device can be a network gate device. The at least one second device can be a human-machine interface device mounted external to the accommodation . The at least one second device may include a network gate device mounted internal to the housing and a deployment device external to the housing. BRIEF DESCRIPTION OF THE DRAWINGS A full understanding of the invention can be obtained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings., in which: Figure 1 is a block diagram of an electrical distribution system that includes a twisted pair field bus network and a "no head" node that interfaces with devices that communicate with the bus of field in gear and an Ethernet communications system; Figure 2 is an isometric view of an electrical distribution system employing wireless communications between various electrical distribution devices in accordance with the present invention; Figure 3 is a block diagram of an electrical distribution system employing wireless communications in a star radio frequency network according to an embodiment of the invention; and Figure 4 is a block diagram of an electrical distribution system employing wireless communications in a star-mesh radio frequency network in accordance with another embodiment of the invention. Description of Preferred Embodiment Forms As used herein, the term "wireless" shall expressly include, but not be limited to, radio frequency (RF), infrared, IrDA, low speed wireless personal area networks (LR-). WPANs), other types of wireless sensor networks, wireless area networks, IEEE 802.11 (eg, 802.11a; 802.11b; 802. llg), IEEE 802.15 (eg, 802.15.1; 802.15.3; 802.15.4), other standards of non-standard communications (eg, without limitation, ZigBee Alliance standard), DECT, PT, pager, PCS, i-Fi, Bluetooth, and cellular. As used herein, the term "communications network" shall expressly include, but not be limited to, Ethernet, any local area network (LAN), wide area network (WAN), field bus, intranet, extranet. , global communications network, the Internet, and / or wireless communications network. As used herein, the term "portable wireless communications device" shall expressly include, but not be limited to, any portable communications device having a wireless communications gate (e.g., a portable wireless device; a wireless display). portable, a portable wireless operator, a portable personal computer (PC), a Personal Digital Assistant (PDA), a data phone).

The present invention is described in association with a control mechanism system, although the invention is applicable to a wide range of electrical distribution systems (e.g., without limitation, motor control centers (MCCs); v.gr., mounted on machine / equipment), panel boards, load centers). Figure 2 shows an electrical distribution system 20 including a housing 22, a plurality of first devices 24, 26, 27, 28 internal to the housing 22, and one or more second devices, such as 30, 31, 32, 33, 34. The first exemplary devices 24, 26, 27, 28 include the protective device 24, the measuring devices 26, 27 and the control device 28. The second devices 30, 31, 32, 33, 34 include the devices 30. , 31 mounted in the housing 22, the devices 32, 33 external to the housing 22, and the monitoring device 34 structured to monitor the system and communicate to a remote location. Communications between the first devices 25, 26, 27, 28 and the second devices 30, 31, 32, 33, 34 employ mis-communications. Example 1 For example, wireless communications can be RF communications and can be provided by a suitable RF communications network, such as a low speed wireless personal area network (LR-WPAN), which is a network of Low-energy short-range RF communications. Examples of suitable transceivers for devices in an LR-WPAN are disclosed in US patent application publications 2004/0233855; and 2004/0235468, which are incorporated herein by reference. Example 2 The electrical distribution system housing 22 can be, for example, a control mechanism or metal cabinet of motor control center or suitable plastic housing. Wireless communications include both internal and external wireless communications (eg, wireless data (message) routing) between the internal devices 24, 26, 27, 28, 34 and the external devices 30, 31, 32, 33, including to the devices 30, 31 on the front surface 36 of the housing 22. For a motor control center housing, for example, the various protective, meter, and control devices 24, 26, 27, 28 are typically installed within individual cabinets 38, which are called buckets. For control mechanism, for example, these individual cabinets 38 are called cartridges, which may contain circuit breakers. Such devices can also be mounted on busbars or cables (not shown). Non-limiting examples of the protective device 24 include circuit breakers, trip units, relay- protectors and motor overload relays. Non-limiting examples of measuring devices 26, 27 include meters (eg, panel mounted current / voltage meters, watt-hour meters, power factor meters, power quality meters), voltage sensors, current and / or temperature (e.g., without limitation, mounted on terminals of existing devices, mounted on busbars (not shown)). Non-limiting examples of the control device 28 include motor starters, contact devices, variable speed drives, timers, programmable logic controllers (PLCs) and other controller devices. The system 20 eliminates the electrical wiring (e.g., the field busbar 4 of Figure 1) that is now used within the control mechanism or engine control center cabinets to communicate information of the protective devices, control devices and / or meters to a local / remote screen or to a computer / remote data center. Example 3 At least some of the first devices, such as 24, may be current driven devices. Examples of suitable current-driven devices are disclosed in US patent applications 10 / 962,682, filed October 12, 2004; and 11 / 038,899, requested on January 19, 2005, which are incorporated herein by reference.

Example 4 The system 20 may include one or more local screens, such as devices 30 or 31, which may be mounted on the front surface 36 of the housing 22, as shown. System 20 may further include one or more portable wireless communications devices, such as devices 32 (e.g., a portable wireless personal computer (PC)) and 33 (e.g., a wireless handheld electronic device (v. .gr., without limitation, a PDA)) which are preferably at least somewhat remote from the front surface of the housing 36. Example 5 The monitoring device 34 may be a network door device mounted internally to the housing 22. This device 34 provides a network to a communication network 40, which can provide information about the system 20 to a remote location (eg, without limitation, a data center, another computer, a remote operator interface screen).; another door device) (not shown). Example 6 The device 31 can be a human-machine interface (HMI) device (eg, an operator's interface) internal to or external to the housing 22. Example 7 The devices 30, 31 can be screens (e.g. , sm limitation, screen devices; annunciators (e.g., indicator panels; light stacking posts)) or operator interfaces which are mounted internal to or external to housing 22, for example, on the external front surface 36 thereof. Example 8 The device 32 may be, for example, a personal computer (PC) with custom software used to monitor and / or control the devices 24, 26, 27, 28 within the housing 22. Example 9 A preferred communications mechanism to a remote location is a suitable facilities communications network, such as an Ethernet communication network 40. The monitoring device 34 can be a network gate device (eg, an RF-to-Ethernet gate device) mounted externally, proximally, in or internally (as shown) to housing 22. This device 34 provides a wired communication network interface, such as the example Ethernet communication network 40, which can provide information about the system. to a remote location (not shown). Example 10 RF communications can be provided over a suitable mesh network. A preferred communications network is a ZigBee Alliance (ZigBee) standard network, which employs networks Flexible, multi-hop, which can follow several architecture topologies, to ensure that a network works with maximum efficiency and reliability. As shown in Figure 2, for maximum flexibility and conflability, the Zigbee mesh topology, where each node (ie, the various devices 24, 26, 27, 28, 30, 31, 32, 33, 34) it is in direct communication with its immediate neighboring nodes, it is an option. If a single node fails for any reason, including the introduction of relatively strong RF interference, then RF messages are automatically routed through alternate paths. Example 11 As an alternative to the system 20 using the mesh network of Figure 2, RF communications can be provided over a star network. With reference to Figure 3, an electrical distribution system 20 'employs a wireless communications network based on a star topology 50 to provide efficient localized communications (one hop). In this star network, a central access point (or master) 52 controls communications between nodes (or slaves), such as 54, 56, 58. However, when physical or RF interference blocks communications between the access point 52 and any of the nodes 54, 56, 58, the star network can not be recovered until that the source of the interference is removed or the system 20 selects and migrates to an alternative frequency channel. The exemplary star network topology is a simple wireless communications network consisting of the master 52 and the slaves 54, 56, 58, such as the protective devices (eg, circuit breakers), measuring devices and / or control devices. Although relatively simple, this topology requires that each of the slaves 54, 56, 58 be able to communicate directly back to the master 52. Example 12 As an alternative to the system 20 employing the mesh network of Figure 2 or the system 20 'employing the star network of Figure 3, RF communications can be provided over a star-mesh network. With reference to Figure 4, an electrical distribution system 20"employs a wireless communication network based on a star-mesh topology 60. A star master 62 is energized by a control voltage, while slaves 64, 66, 68, 70 can be self-energized Star Master 62 is part of a mesh network that allows communications to all of the nodes.If a mesh node failed, then alternative routing paths would automatically be discovered. IEEE 802.15.4 is the concept of mesh formation, in the example star-mesh network, instead of requiring that each node, such as protective devices, measuring devices and / or control devices, be communicate to a single node (eg, master 52 of Figure 3), the node only needs to communicate to an adjacent device. For example, the nodes 72, 74, 76 can communicate through the nodes 64, 70, 68, respectively, to communicate with the master 62. Alternatively, in this example, the node 74 can communicate through the node 68 and the node 76 can communicate through the combination of nodes 78 and 66 with master 62. Therefore, physical interference or RF is much less of a problem. Information can be routed from device to device between any two nodes. It is important that any node that is essential to routing, such as nodes 64, 74, 76, is energized and active at all times. In contrast, those nodes, such as 66, that are not essential to routing (since one or more alternative paths exist), do not need to be energized at all times and, thus, the electronics of the device can be self-energized, for example, by a load current of the circuit breaker. The combined 60-star-mesh topology or super-star configuration combines the benefits of both mesh and star topologies. This is preferably applied in cluster-type networks, where local star nodes, such as 72, are relatively simple nodes that can be energized as a parasite, which communicate with full-function nodes, such as 64, who are always energized and have the ability to communicate about a mesh. As such, the super-star topology provides both efficiency and flexibility. Example 13 Although the above examples assume a complete conversion from wired communications to wireless communications between the various first and second devices associated with the electrical distribution system housing 22, it will be appreciated that hybrid communications can be provided for the various first and second devices. , such as 24, 26, 27, 28, 30, 31, 32, 33, 34, such that one or more such first and second devices is an island of wired components, which island communicates among the various other first devices and seconds using wireless communications. In other words, any one or more of the various first and second devices may include plural sub-devices communicating with each other via wired communications (e.g., without limitation, employing a wired field bus), such that one such sub-device plural devices act as a single "wireless" node for the other plural sub-devices and provide wireless communications between the various other first and second devices. The disclosed systems 20, 20 ', 20"which employ RF communications, can have many advantages over the previous wiring system 2 (figure 1) including: (1) isolation and immunity from damaging voltage transients; (2) the ability, due to LR-WPAN low-energy communications, to add communications to additional devices, such as circuit breakers, without requiring additional external control power or wiring; and (3) at least one communications node, such as devices 30, 31, 32, 33, may be outside the housing. This feature provides extra security (e.g., without limitation, of an arc flash) since the user does not need to be directly in front of the housing 22, such as a control mechanism or motor control center cabinet. Although for clarity of disclosure reference has been made herein to the exemplary screen, such as 30, to display information regarding the system 20, it will be appreciated that such information may be stored, printed on paper, modified by computer, or combined with other data. . All such processing shall be considered falling within the terms "screen" or "displayed" as used herein. Although specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are intended to be illustrative only and not limiting as to the scope of the invention, to which it will be given the full scope of the appended claims and all and any equivalent thereof.

Claims (20)

1. CLAIMS 1. An electrical distribution system (20, 20 ', 20") comprising: a housing (22), a plurality of first devices (24, 26, 27, 28) internal to said housing, said first devices being protective devices, meters, or control; and at least one second device (30, 31, 32, 33, 34), said at least one second device being (30, 31) mounted in said housing, being (32, 33) external to said housing or being a monitoring device (34) structured to monitor said system and communicate with a remote location, where communications between said first devices and said at least one second device are wireless communications.
2. 2. The electrical distribution system (20, 20 ', 20") of claim 1, wherein said wireless communications are radio frequency communications
3. 3. The electrical distribution system (20, 20', 20") of the claim 2, wherein said radio frequency communications are provided by a radio frequency communication network.
4. 4. The electrical distribution system (20, 20 ', 20") of claim 3, wherein said communications network of Radio frequency is a low speed wireless personal area network.
5. The electrical distribution system (20, 20 ', 20") of claim 2, wherein said radio frequency communications are provided over a mesh network 6.
6. The electrical distribution system (20, 20', 20) ") of claim 2, wherein said radio frequency communications are provided over a star network.
7. The electrical distribution system (20, 20 ', 20") of claim 2, wherein said radio frequency communications are provided over a star-mesh network 8.
8. The electrical distribution system (20, 20' , 20") of claim 1, wherein said housing is a control mechanism cabinet or motor control center (22).
9. The electrical distribution system (20, 20 ', 20") of claim 1, wherein at least some of said first devices are current driven devices (24)
10. 10. The electrical distribution system (20, 20) ', 20") of claim 1, wherein said first devices are selected from the group consisting of protective devices (24), control devices (28) and measuring devices (26, 27).
11. 11. The electrical distribution system (20, 20 ', 20") of claim 10, wherein said protective devices res (24) are selected from the group consisting of circuit breakers, trip units, protective relays and motor starters.
12. The electrical distribution system (20, 20 ', 20") of claim 1, wherein said at least one second device is a portable wireless communications device (32, 33) 13.
13. The electrical distribution system ( 20, 20 ', 20") of claim 12, wherein said portable wireless communications device is a personal digital assistant (33).
14. The electrical distribution system (20, 20 ', 20") of claim 1, wherein said at least one second device is a screen (30) or operator's interface (31) which is mounted external to said housing
15. 15. The electrical distribution system (20, 20 ', 20") of claim 1, wherein said housing includes an external surface (36); and wherein said at least one second device is a screen (30) or operator's interface (31) which is mounted on the external surface of said housing.
16. 16. The electrical distribution system (20, 20 ', 20") of claim 1, wherein said at least one second device is a network gate device (34)
17. 17. The electrical distribution system (20, 20 ', 20") of claim 16, wherein said door device network is mounted internal to said housing.
18. 18. The electrical distribution system (20, 20 ', 20") of claim 16, wherein said network gate device is an Ethernet gate device (34)
19. 19. The electrical distribution system (20, 20', 20") of claim 1 , wherein said at least one second device is a human-machine interface device (31) mounted external to said housing. The electrical distribution system (20, 20 ', 20") of claim 1, wherein said at least one second device includes a network gate device (34) internally mounted to said housing and a deployment device ( 30, 31) external to said housing.