Monitoring of each socket residual current of power distribution device

Abstract

Power distribution systems and methods in which a power distribution unit (PDU) is provided with residual current monitoring at a plurality of sockets of a socket module in the PDU. A residual current monitoring circuit of a PDU includes at least one current sensor associated with outlets of the PDU for detecting a residual current of each outlet. A method of detecting residual current in a PDU having a plurality of power outlets includes detecting a current leakage at each outlet, i.e., a difference between a supply current and a return current for each outlet.

Description

Technical Field

[0001] The present disclosure generally relates to power distribution devices configured to reduce electrical hazards. More specifically, the present disclosure relates to power distribution devices that provide residual current monitoring at outlets of the power distribution devices. Background Art

[0002] A traditional power distribution unit (PDU) is an assembly of power outlets (also called receptacles) that receive power from a power source and distribute the power to one or more independent electronic devices. Such a PDU assembly has a power input that receives power from one or more power sources through the power cord of the PDU. The power outlets can be used to provide power to one or more electronic devices plugged into the PDU outlets. PDUs can be used in a variety of applications and settings, such as within or on an electronic equipment rack.

[0003] A common use of PDUs is to provide operating power to electrical equipment in computing facilities, such as enterprise data centers, multi-tenant hosting environments (such as colocation facilities), cloud computing, and other types of data centers. Such computing facilities may include electronic equipment racks, which consist of rectangular or box-shaped enclosures (sometimes called cabinets or racks) and related components for mounting the equipment, related communication cables, and related power distribution cables. Electronic equipment may be installed in such racks so that various electronic equipment (such as network switches, routers, servers, etc.) can be mounted vertically in the rack, one on top of the other. One or more PDUs may be used to power the electronic equipment. Multiple racks may be installed side by side, each containing many electronic components and a large amount of related component wiring inside and outside the area occupied by the rack. Such racks typically support equipment used in enterprise computing networks (referred to as enterprise networks). Enterprise data centers, multi-tenant hosting environments (such as colocation facilities), cloud computing, and other types of data centers are often critical to business operations. Therefore, the electrical connections between the PDUs and their related servers, storage, and network equipment must be secure to ensure the uptime of the equipment and provide reliable support to enterprise users.

[0004] Data centers rely on high voltage power distribution, and if any of the safety features designed into the power distribution system are compromised, operators and maintenance personnel are at risk of serious injury in the event of an electrical fault. The insulation surrounding hazardous voltage conductors is one such safety feature. If the insulation is compromised due to age, mechanical stress, or damage during installation, it can become fatal to personnel working in and around the lines. Additionally, components of the electrical infrastructure and IT loads connected to the power distribution system can fail and provide a path for leakage currents, which can be dangerous if personnel come into physical contact with these devices.

[0005] As a result, the industry requires proactive identification of risks of injury to workers in these facilities due to potential residual currents or leakages. An example is the industry standard DIN VDE 0105-100 VDE 0105-100:2015-10: Operation of electrical installations. The standard specifies the need to periodically perform isolation measurements on the power distribution system to determine the source of insulation breakdown. This typically requires removing power from part of the distribution chain in order to perform the isolation measurements. This can be very problematic in data centers where uptime is critical and the cost of downtime is extremely high.

[0006] To minimize the impact on mission-critical, high-reliability systems and installations, the standard allows for longer intervals between inspections if the residual current is continuously monitored and an alarm function is provided when an increase in leakage current is detected. As a result, the need for continuous monitoring and alarming of residual current within rack PDUs is increasing. In addition, continuous residual current monitoring (RCM) is becoming a mandatory feature in some jurisdictions.

[0007] Current methods of implementing RCM are expensive and therefore limited to monitoring the power lines to the rack PDU. A typical three-phase power line can provide 22KVA (or more) of current to the IT loads connected to the rack PDU, so a single power line can support a large number of IT loads (such as 48 or more). The current mainstream residual current monitoring (RCM) solution is to monitor at the power line entrance of the PDU. Bender GmbH provides an example in its publication "Product Overview: Residual Current Monitoring" (January 2021), where the line and neutral conductors of the power line are first routed through highly sensitive current transformers and then routed to the IT loads at the rack PDU outlets. Under normal operating conditions, all current flowing out of the line conductor should be equal to the current returning through the neutral conductor, so there will be no current in the secondary winding of the RCM current transformer. Any current detected on the secondary winding of the RCM current transformer represents leakage current flowing from the line conductor to the protective earth instead of the neutral conductor. It is this leakage current path that can pose a hazard to people who come into physical contact with equipment where this leakage current exists.

[0008] In another known RCM example, the three-phase and neutral conductors from the three-phase incoming power line pass through a toroidal RCM current transformer (CT). The transformer wires are then connected to a meter board, which converts the transformer secondary current output to a voltage that is digitized by an A / D converter on a microcontroller on a printed circuit board within the PDU. Additional wire wrapped around the transformer core demagnetizes the current transformer to eliminate any residual magnetic field. This can occur after a high current fault event downstream of the PDU.

[0009] By using these two known RCM implementations, the end user can only determine that there is a fault on the input power line downstream of the rack PDU and that it is generating excessive residual current. These RCM implementations do not provide any additional fault isolation information to help personnel determine if one or more IT loads have failed, or if the rack PDU has failed. Therefore, while monitoring the input lines meets the requirement for continuous monitoring of residual current, it does not allow for quick location determination of the IT device (i.e., the specific outlet of the PDU) that is causing the excessive leakage current. This can result in excessive downtime while attempting to locate and repair the faulty IT equipment.

[0010] In other RCM technologies, additional residual current sensors are provided to monitor each phase of the three-phase power line and determine at least where the faulty equipment is generally present. For example, in one known RCM installation, up to six (6) RCM sensors may be connected to each power branch in a rack PDU. This solution helps to further isolate the residual current fault or leakage to a branch or collection of outlets. There are two main types of known RCM sensors included in rack PDUs: i) Type A, which monitors AC current from 42 - 2000Hz (in accordance with International Electrotechnical Commission Standard IEC-60755); and ii) Type B, which measures AC current (up to 2000Hz) as well as pulsating and smooth DC current (in accordance with IEC-60755). Type B RCM monitoring can detect DC leakage current (smooth and pulsating) in addition to AC leakage current. Type B is suitable for PDU applications using switch mode power supply technology for high-end servers and IT equipment that are prone to failure due to damage caused by DC leakage current. However, while residual current monitoring can be performed on each branch, this RCM technology still cannot quickly identify the outlet location of the connected IT equipment that causes excessive leakage current.

[0011] U.S. Patent No. 8,694,272 and U.S. Patent No. 8,305,737 each show and describe a rack PDU with a power sensing and monitoring system, wherein each outlet or receptacle includes a single current transformer (CT) for measuring the current on the outlet power cord pins. Power sensing and monitoring can be used to provide power-related information to entities that supply, deliver, and consume power. U.S. Patent No. 8,694,272 specifically describes a PDU with a monitoring system that monitors the power consumption of each outlet of the PDU, namely "Per Outlet Power Sensing (POPS)". However, neither of these patents shows or describes residual current monitoring. U.S. Patent No. 8,907,678 shows and describes an apparatus and method for monitoring current leakage from an AC power source to IT equipment (such as a PDU in a data center), but does not provide how to identify the specific outlet and the connection source of the current leakage.

[0012] Therefore, there remains a need for systems and methods for monitoring residual current at each outlet within a PDU to provide maintenance personnel with additional fault isolation information, enabling them to identify and correct fault conditions and restore affected IT equipment with minimal impact to system uptime. Summary of the invention

[0013] Systems and methods for residual current monitoring at a socket-level PDU are provided. Preferred embodiments of the PDU provide data center IT and facility personnel with enhanced information that enables them to more easily locate faulty (or failed) IT equipment that exhibits an increase in residual current leakage. Preferred embodiments of a residual current monitoring circuit used in a PDU include two current sensors associated with a socket of the PDU for detecting a difference between a line current supplied to the socket and a return current from the socket. Thus, a preferred method can provide residual current detection in a power distribution device having a plurality of power sockets, and detect current leakage at each socket as the difference between the supply current and the return current of each of the plurality of sockets.

[0014] A preferred embodiment of a power distribution device includes a power distribution device housing and a power supply disposed in the housing, the power supply having a plurality of input conductors. The PDU includes a plurality of outlets disposed in the housing, each outlet having a plurality of connectors, the plurality of connectors including a first connector electrically connected to one input conductor and at least a second connector electrically connected to a different input conductor. Each outlet has an associated residual current monitoring circuit, the circuit having at least a current sensor associated with the first connector and the second connector for determining a residual current of each outlet.

[0015] A preferred embodiment of a power distribution device includes a power distribution device housing and a power supply disposed in the housing, the power supply having a plurality of input conductors. The PDU includes a plurality of sockets disposed in the housing, each socket having a plurality of connectors, the plurality of connectors including a first connector electrically connected to one input conductor and at least a second connector electrically connected to a different input conductor. Each socket has an associated residual current monitoring circuit having a first current sensor associated with the first connector to determine a first current detection output; and a second current sensor associated with at least the second connector to determine a second current detection output. The preferred PDU includes a differential detector coupled to the associated residual current monitoring circuit of each socket to determine a current difference between the first current detection output and the second current detection output of each socket.

[0016] A preferred embodiment of the socket module includes at least one circuit board; a first pair of current sensors mounted on the at least one circuit board; at least a second pair of current sensors mounted on the at least one circuit board; at least one differential detector mounted on the at least one circuit board for determining the difference between the current detection outputs of each pair of current sensors; a first power socket associated with the first pair of current sensors; and at least a second power socket associated with the at least second pair of current sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The nature and advantages of the disclosed technology may be further understood with reference to the following drawings. In the drawings, similar components or features may have the same reference numerals.

[0018] Figure 1 is a schematic diagram of a preferred embodiment of a power distribution unit (PDU); Figure 2 yes Figure 1 A partial block diagram of the PDU with power input and network connections; Figure 3 is used for Figure 1 A block diagram of a preferred embodiment of a socket module of a PDU; Figure 4 is used for Figure 1 A block diagram of another preferred embodiment of a socket module of a PDU; Figure 5 is used for Figure 1 A block diagram of another preferred embodiment of a socket module of a PDU; Figure 6-Figure 7 is used for Figure 3-Figure 5 Various exploded perspective views of the sockets of the socket module; Figure 8-Figure 9 is used for Figure 1 Various exploded perspective views of a preferred embodiment of the socket module of the PDU; Fig.10 yes Figure 8-Figure 9 A perspective view of a socket module; Fig.11 yes Fig.10 A cross-sectional view of a socket module; Figure 11A-11B is used for Figure 1 Schematic diagram of an alternative embodiment of an outlet module for a PDU. DETAILED DESCRIPTION

[0019] This description provides examples and is not intended to unnecessarily limit the scope, applicability or configuration of the present invention. On the contrary, the following description will provide a favorable description of implementing embodiments of the present invention for those skilled in the art. The functions and arrangements of the elements may have various changes. Therefore, various embodiments may omit, replace and / or add various programs or components as appropriate. For example, aspects and elements described for certain embodiments may be combined in various other embodiments. It should also be understood that the following systems, devices and elements may be used individually or together as part of a larger system, wherein other programs may take precedence over or otherwise modify their application.

[0020] Exemplary preferred embodiments of a power distribution unit (PDU) are described herein. The exemplary embodiments provided by the present disclosure are capable of determining the residual current or leakage current of each socket of the PDU. A preferred PDU with multiple sockets and a residual current monitoring method based on monitoring each socket help to effectively determine the source of the leakage current. Based on this knowledge, it is possible to minimize downtime in the data center and / or reduce or eliminate electrical hazards to personnel.

[0021] Figure 1An exemplary embodiment of a PDU 10 is shown, which includes a housing 12 having a plurality of outlets 20 (also referred to as "sockets" or "outputs") mounted thereon for powering various assets or equipment, such as assets used in data center operations. These assets can be mounted on an equipment rack and appropriately plugged into one of the outlets 20 of the PDU. Thus, the PDU 10 can be configured to be mounted vertically or horizontally. In order to supply and distribute power to the connected assets through the outlets 20, the PDU 10 is configured to receive power input internally. As shown, the PDU can include an internally wired input power cord 30 that extends externally and terminates at an associated plug 32 for connection to a power source in a conventional plug and socket connection manner. Alternatively, the PDU 10 can also be configured to be internally hardwired to connect to an external power source. The PDU 10 can include a visual display portion 40 for displaying monitoring information, such as displaying which outlet of the PDU has detected a current leak. The visual display can also display other information, such as power consumption, voltage, and / or current of each outlet. Alternatively or additionally, the PDU 10 may also be coupled to an external display to communicate such information. As described herein, the outlets 20 may be grouped and configured to define one or more outlet modules 200. For example, each outlet module 200 of the illustrated PDU 10 preferably includes six outlets 20a-20f. However, it should be understood that preferred embodiments of the outlet module 200 may include fewer or more outlets 20 as long as at least one outlet, preferably more than one outlet, is configured with a residual current monitoring function in the manner described herein.

[0022] Figure 2The block diagram of FIG. 1 shows an illustrative system 2 that includes a preferred PDU 10 for providing power to one or more associated computing assets (e.g., devices of a computing network 4). The PDU 10 can communicate with a data center operator or a network application (e.g., a power manager application 6 using a workstation or other device used to manage a data center or other enterprise and connected to the network 4) via the computer network 4. As shown in the schematic diagram, the preferred outlet module 200 of the PDU 10 is connected and configured with a residual current monitoring (RCM) circuit 100 that can detect or determine the residual current or leakage of each outlet 20a-20n of the module 100. Therefore, the preferred embodiment of the PDU 10 is configured to provide residual current monitoring on a "per outlet" basis. Generally speaking, each outlet has an associated RCM circuit 100, which preferably includes a first current sensor 100a and a second current sensor 100b in combination with a differential detector 110. In an AC environment, the first current sensor 100a and the second current sensor 100b can also be used to alternately determine the current provided to the associated outlet 20 and the current returned through the outlet. Each sensor 100a and 100b generates or defines a current detection output indicating a detected current provided to a differential detector 110. The differential detector 110 determines whether there is a difference between the current detection outputs of the first and second current sensors 100a and 100b to determine whether there is a residual current or leakage. In the preferred embodiment described herein, the differential detector 110 is embodied as a microcontroller 110. The microcontroller 110 is preferably configured to communicate the detected residual current to a display screen 40, or to communicate the residual current to a networked device or operator via a network 4 so as to resolve the problem with appropriate personnel. Therefore, the PDU 10 preferably includes a network interface card 60, which is used to communicate with devices on the network 4, and can also be configured for internal communication between the PDU 10 modules 200.

[0023] Figure 3-Figure 5Shown is a block diagram of a preferred outlet module 200 and RCM circuit 100 electrically connected to a power input via an internal power source or power source 112 of the PDU 10. The power source 112 includes a plurality of conductors for transmitting one or more phases of the power input to the PDU 10. As shown, each outlet 20a-20h of the module 200 has two or more connectors 22 for electrically connecting to two conductors of the power source 112. Each outlet 20a-20h also includes an associated preferred residual current monitoring circuit 100. Each residual current monitoring circuit 100 includes a first current sensor 100a associated with one connector 22a of the outlet 20, and a second current sensor 100b associated with another connector 22b of the outlet 20. A preferred differential detector 110 is electrically connected to each current sensor 100a and 100b to receive the current sense output of each current sensor 100a and 100b of each outlet 20 in the module 200. The preferred embodiment of the socket module described herein may include a voltage detection resistor network 120 to determine the voltage of each socket 20a-20h and other power-related parameters described herein. Each socket 20a-20h is also interconnected to the ground GND in the power supply 32, although Figure 3-Figure 5 These connections from sockets 20a-20h are not shown.

[0024] Figure 3 Specifically shown is an exemplary embodiment of a preferred module 200 electrically connected to two conductors L1, L2 of a power source 112. Depending on the configuration of the power source 112, the first conductor L1 can be connected to the line power in the power source 112, and the conductor L2 can be connected to the neutral conductor in the power source 112. Therefore, the outlet module 200 can be configured so that each outlet 20 has one connector 22a electrically connected to the first conductor L1 carrying the line power, and another connector 22b electrically connected to the second conductor L2 as a neutral conductor. Alternatively, in a multi-phase configuration of the power source 112, the conductors can be connected to different phases of the power source 112. Therefore, for example, each outlet 20 of the module 200 can have one connector 22a electrically connected to the first phase line power, and another connector 22b electrically connected to the second conductor L2 carrying the second phase line power.

[0025] As shown in FIG. 4 and FIG. 5 , in the case of a multi-phase power supply 112, the PDU 10 may have a delta-type or Y-type power input configuration. As shown in FIG. 4 , the power supply 112 adopts a three-phase power input in a delta configuration, having a first conductor L1 carrying a first phase, a second conductor L2 carrying a second phase, and a third conductor L3 carrying a third phase. The preferred PDU 10 in FIG. 4 shows three socket modules 200a, 200b, and 200c, and the sockets 20 are electrically connected to the conductors L1, L2, and L3 in different combinations. More specifically, the socket connectors 22a and 22b of the first module 200a are electrically connected to the first and second conductors L1 and L2, the socket connectors 22a and 22b of the second module 200b are electrically connected to the second and third conductors L2 and L3, and the socket connectors 22a and 22b of the third module 200c are electrically connected to the first and third conductors L2 and L3. Alternatively or additionally, the power input to the power supply may include a neutral line N. Thus, for example, any conductor 22b with a current sensor 100b for detecting return current may be electrically connected to a conductor or neutral line. Each module 200a, 200b, 200c preferably includes a microcontroller 110a, 110b, 110c for receiving the current detection output from the associated current sensor 100a, 100b of each socket 20. By determining the difference between the currents carried by the connectors 22a, 22b of the sockets 20, the microcontroller 110a, 110b, 110c can detect the residual current or leakage of each socket 20 associated with the module 200a, 200b, 200c, respectively.

[0026] In the case of a neutral line, the power input can be a delta configuration or a Y configuration. FIG. 5 shows a power supply 112 whose power input adopts a Y configuration. The power supply 112 shown in the figure has four conductors, including a first conductor L1 carrying a first phase, a second conductor L2 carrying a second phase, a third conductor L3 carrying a third phase, and a fourth conductor N on the neutral line. Each socket 20 in each module is electrically connected to the neutral conductor N, preferably for detecting the return current using a secondary current sensor 100b. The sockets 20a-20h in the common socket module 200 are preferably connected to the common conductor of the input power, while different modules 200a, 200b, 200c are electrically connected to conductors of different phase input power. Figure 5The preferred PDU 10 in FIG. 1 shows that the first connectors 22a of the sockets of the three socket modules 200a, 200b, 200c are electrically connected to the conductors L1, L2, and L3, respectively. The associated current sensor 100a of the first connector 22a in each socket 20 can detect the current supplied to the socket. Similarly, each socket module 200a, 200b, 200c preferably includes a microcontroller 110a, 110b, 110c for receiving the current detection output of the respective associated current sensor 100a, 100b of each socket 20a-20h. By determining the difference between the currents carried by the connectors 22a, 22b of each socket, the microcontroller 110a, 110b, 110c can therefore detect the residual current or leakage of the respective associated module 200a, 200b, 200c per socket.

[0027] Figure 6-Figure 7 Shown is a perspective view of a preferred socket assembly 20', which includes two current sensors 100a, 100b for residual current monitoring. The socket 20' generally includes a core 220, in which two or more connectors 222 are fixed for electrically connecting to power conductors to power a device or asset plugged into the socket 20'. A preferred embodiment of the socket assembly can be constructed as a combined socket shown and described in U.S. Patent Application Publication No. 2021 / 0288434 filed on March 16, 2020; U.S. Patent No. 10,249,998 filed on July 13, 2017 and U.S. Patent No. 10,498,096 filed on April 1, 2019, the entire disclosures of which are hereby incorporated herein by reference in their entirety.

[0028] The socket assembly 20' includes a preferred core 220 having an input face 220a and an opposite bottom face 220b, with three holes 220c extending between the input face and the bottom face. The core 220 can be formed of injection molded plastic, for example, with an outer surface configured to mate with one or more connector types. For example, the outer surface of the core 220 can be configured as a C13 socket that mates with a C14 plug with rectangular holes 220c to receive terminals in a corresponding orientation. The outer surface or holes 220c of the core can also be configured to receive two or more types of plugs, i.e., a "combination socket", as shown and described in U.S. Patent No. 10,498,096 (incorporated herein by reference), and as shown in the three cores of the module 200' of Figure 8, with T-shaped holes for receiving two types of plugs.

[0029] Reference again Figure 6 and Figure 7, the socket assembly 20' may include a first power terminal 222a and a second power terminal 222b extending from the bottom surface 220b. The socket 20 may include a ground terminal 222c to define a third connector for electrically connecting to a ground conductor (e.g., a ground conductor GND) of a power source. The terminals 222a, 222b, 222c may be made of a suitable conductive material, such as tin, gold, silver, copper, phosphor bronze, etc. A variety of materials may be used in combination. In one embodiment, the terminal may be composed of a tin-plated copper alloy. Standard socket / plug types (such as C13, C14, C19, and C20) all refer to industrial standard connectors defined in the International Electrotechnical Commission (IEC) standard publication IEC60320 on the date of filing this application. Although the embodiments show and describe C13 / C14 and C19 / C20 sockets / plugs, other combinations may also be used. Other suitable connector types may include, but are not limited to, industry standard receptacles / plugs such as IEC C2, C4, C6, C8, C10, C12, C16, C16A, C18, C22, C24 or NEMA 5-10R, 5-15R, 5-20R, 6-20R, 6-30R, 6-50R, L15-20R, L15-30R, L21-20R, L21-30R.

[0030] Included in the socket assembly 20' and shown in the cross-sectional views of Figures 6 and 7 are preferred embodiments of current sensors 100a and 100b connected to the first and second terminals 220a and 220b of the socket 20'. The current sensors 100a, 100b can be embodied as toroidal current transformers, such as current transformers (CTs). The current transformer (CT) preferably used is manufactured by Hebei Shenke Electronics Co., Ltd., China, with part number 1HKW.506.6940.1C. The maximum primary operating current of the example CT is 40A, the turns ratio is 1:2000, and the load resistance is 10Ω. In the preferred embodiment shown, the current sensors 100a, 100b are current transformers, whose output lines include two output leads 102a, 102b. The preferred current transformer (CT) 100a, 100b is annular, and the power terminals 222a, 222b of the socket 20' extend through the annular openings of the sensors 100a, 100b, so that the sensors and the socket 20' are connected to each other. The detection current output by the sensors 100a, 100b is proportional to the current flowing through the conductor or power terminals 222a, 222b associated with the sensors 100a, 100b. In a preferred embodiment of the socket assembly 20', the current detection output of the sensors 100a, 100b can be output through a load resistor on the two output leads 102a, 102b of each sensor. As an alternative or supplement, in addition to the current sensors 100a, 100b and the associated microcontroller, one or more residual current monitoring circuits 100 may also include a load resistor and an anti-aliasing filter.

[0031] Figure 8-Figure 10Various cross-sectional views of a preferred module 200' are shown, which is equipped with six sockets 20'a-20f, which are arranged in a module tray or housing 230 and are engaged with preferred circular current sensors 100a, 100b. Preferably, the sensors 100a, 100b are mounted together with corresponding output leads 102a, 102b mounted on a printed circuit board PCB 240. Therefore, the two sensors 100a and 100b are located between the socket core 220 and the PCB 240, preferably between the module housing 230 and the PCB 240. Figure 11 shows a cross-sectional view of a preferred socket module 200'. The module 200' is assembled in a compact manner in the housing 12 of the PDU 10, and a pair of sensors are preferably located within the width W1 of the PCB 240 and / or within the width W2 of the module housing 230. In the preferred embodiment shown, the current sensors are offset from each other, with one sensor 100b mounted closer to the PCB 40 than the other current sensor 100a. In addition, the sensors 100a and 100b may partially overlap each other as long as the sensors 100a and 100b can be mounted on the PCB 240. For embodiments where the paired current sensors 100a, 100b are offset or stacked in the assembly, preferably, the total height H of the space between the PCB 240 and the housing 230 containing the sensors 100a, 100b is less than twice (2X) the depth D of the housing 230 and between 1 and 1.5 times (1X-1.5X) the depth D of the housing. In addition, the sensors 100a and 100b may also be mounted on the PCB 240 so as to be located in a plane with each other. Preferably, the core 220 of each socket 20a-20e is oriented in the housing 230 so that each face 220a is located in a common plane. Preferably, the module 200' includes a PCB 240 for mounting each of the first current sensor 100a and the second current sensor 100b. Other embodiments of the module 200' may include at least two printed circuit boards for mounting the two current sensors 100a and 100b on different printed circuit boards. As shown, one or more PCBs 240 may be parallel to the common plane of the face 220a of the core. Alternatively, as shown in FIG. Fig.11 As shown in dashed lines, one or more PCBs 240' and one or more connectors 222b' may be oriented such that the PCB 240' and associated mounted current sensors (not shown) are perpendicular to the face 220a of the core.

[0032] Fig.11A and Fig. 11BShown is a schematic diagram of an alternative embodiment of a socket assembly for use with the socket module described above. Generally speaking, each alternative embodiment of the socket assembly includes one or more current sensors arranged around one or more power terminals to provide residual current monitoring for the associated socket. FIG. 11A specifically shows two current sensors 100a, 100b, one of which is arranged around two or more power terminals. As shown, the first current sensor 100a is disposed on the first power terminal 222a of the socket assembly 20'' for detecting the current supplied to the socket through the terminal 222a; unlike the previously described embodiment, the second current sensor 100b of the assembly is disposed around the first and second power terminals 222a and 222b for residual current monitoring of the socket assembly 20''. By integrating this alternative embodiment of the socket assembly 20'' into the socket module 200, residual current monitoring can be provided on a per-socket basis, wherein one or more sockets have a sensor 100a for supply current detection, and a separate sensor 100b for residual current monitoring.

[0033] Shown in FIG. 11B is another alternative embodiment of a socket assembly 20''' having a single current sensor 100 disposed about each of the first and second power terminals 222a, 222b for use only in residual current monitoring, rather than current monitoring. Thus, by integrating this alternative embodiment of the socket assembly 20''' into the socket module 200, residual current monitoring may be provided on a per-socket basis, with one or more sockets having a single sensor 100 dedicated to residual current monitoring.

[0034] Reference again Fig.11 , the power terminals 222a, 222b, 222c can be constructed and assembled within the module 200' in a manner similar to that shown in the document of U.S. Patent Application Publication No. 2021 / 0288434 (incorporated herein by reference). In order to determine the preferred spacing between the module housing 230 and the PCB 240, the second terminal 222b can be arranged to extend to each side of the PCB 240 or pass through the PCB 240. In addition, one or more power terminals 222a, 222c of the socket can be connected together by a common conductor. For example, each first conductor 222a in each socket 20a--20e has a hole 226 through which a common conductor (e.g., a first conductor L1) can extend. Similarly, the third conductor 222c in each socket 20a-20e can have a hole formed therein to receive a ground conductor GND' connected to the ground and connect the third conductors 222c to each other.

[0035] As shown herein, the bottom surface 220b of the core 220 can be configured to be mounted within a module housing 230. The sockets 20a-20e can be spaced equidistantly from one another or spaced at different distances from one another. The sockets can also define gaps or spaces between the core 220 and the inner wall of the housing to accommodate different types of plugs. The sockets 20a-20e can have unobstructed spaces between adjacent socket cores 220, or a wall can extend between each socket. If there is no space or wall between the sockets, the module 200' can be configured with a high-density socket design, such as the high-density socket design further described in the patent literature of co-owned U.S. Patent Nos. 9,614,335 and 9,627,828, each of which is incorporated herein by reference. The housing 230 can include one or more latch bars 232 that can be operated or pivoted to retain or remove a plug engaged with the socket of the module 200'. The construction and installation of the latching lever 232 are shown in the document of U.S. Patent Application Publication No. 2021 / 0288434. The latching lever 232 can be pivotally coupled to the housing 230 adjacent to each socket 20a-20e. Each latching lever 232 can be moved (e.g., pivotable) between a latched position (in which a mating plug can be inserted and retained) and an unlatched position (in which a mating plug can be removed from the module 200').

[0036] A differential detector, preferably implemented as a microcontroller (not shown), may be mounted on the PCB 240 of each outlet module 200'. An example of a microcontroller used in the PDU 10 is a 32-bit ARM Cortex M4 (with embedded DSP core) from STMicroelectronics, part number STM / STM32F446ZC. The microcontroller 110 may determine other current and power-related parameters of the outlet module 200 and the PDU 10. More preferably, the microcontroller 110 is configured to monitor, detect, and report power-related parameters on a per-outlet basis, as shown and described in any of U.S. Patent Nos. 8,321,163, 8,305,737, 8,694,272, or 9,952,261, each of which is incorporated herein by reference. Therefore, referring to FIG. 2 , in addition to the preferred residual current monitoring circuit 100 and the voltage detection circuit 120, preferably, each module 200a, 200b, 200c ... ... 200n of the preferred PDU 10 also includes a relay device 140 and a relay drive circuit 150, each relay device and relay drive circuit 150 are electrically connected to the microcontroller 110. Therefore, preferably, each module 200a, 200b, 200c ... ... 200n is configured as a smart socket module of the PDU 10. In addition, the PDU 10 may also include a residual current monitor for the input line. As shown in FIG. 2 , the PDU 10 may include an internal input line residual current monitor 160 having one or more current sensors, wherein a single-phase or multi-phase input line is associated with a current transformer (CT) to detect current leakage. In addition, the PDU may also include an input power meter 161 having an upstream RCM (as shown) or a downstream RCM (not shown). Preferably, the current sensor of the input line residual current monitor 160 is type B, which can measure AC current (up to 2000 Hz) and pulsating and smooth DC current in accordance with IEC-60755. The preferred embodiment of the PDU can perform residual current monitoring of AC current at the socket, preferably in the range of 42-2000 Hz.

[0037] By providing the preferred embodiment of the PDU 10 with the residual current monitoring functionality described herein, additional fault isolation information can be provided to maintenance personnel, enabling them to correct the fault condition and restore the affected IT equipment while minimizing the impact on system uptime. Like the PDU in the literature of U.S. Patent No. 9,952,261, the preferred embodiment of the PDU 10 can be configured with "power per outlet detection" or ("POPS"), which refers to the concept of detecting the load coupled to each outlet and monitoring the power consumption of each outlet. Therefore, since the preferred microcontroller 110 of the outlet module can receive current information and voltage information for each outlet 20 of the module 200, the load detection of each outlet and various power-related indicators can be calculated and reported to the network power manager 6 or other network-connected computer or device via the network 4. The microcontroller 110 can be interconnected with a communication bus (such as an RS485 bus, an I2C bus, or an SMBus). A preferred embodiment of the PDU 10 may include a microcontroller 110 for reporting, via the network 4, for each outlet: (a) residual current (RC); (b) voltage RMS (Vrms); (c) current RMS (Irms); (d) apparent power (VA); (e) real power (W); (f) power factor (pF); and (g) crest factor. This data may be received by an external system that collects the outlet information providing the data and uses it to determine metrics or provide the above information. Monitoring the power consumption of each outlet through an Internet interface may provide detailed power consumption information, and outlets may be grouped to determine kilowatt power consumption per device, group of devices, PDU, or cabinet. As described above, power consumption may also be determined per rack, per row of racks, for an entire data center, etc. by clustering outlet information for multiple IP addresses and PDUs. This provides consolidated PDU information within the data center or across multiple locations, a centralized view of power and environmental status, capacity planning, reporting and trending, multiple views, automatic discovery of all PDU devices, alarm details, the ability to manage PDUs, global or individual outlet control, and logging.

[0038] It will be appreciated by those skilled in the art that various illustrative logic blocks, modules, circuits, and algorithmic steps associated with the embodiments disclosed herein may be implemented as electronic hardware, computer software, firmware, or a combination thereof. In order to clearly illustrate this interchangeability, various example components, blocks, modules, circuits, and steps have been generally described above according to their functions. Whether these functions are implemented in the form of hardware, software, and / or firmware depends on the specific application and design restrictions on the entire system. A skilled person may implement the functions in different ways for each specific application, but such implementation decisions should not be interpreted as departing from the scope of the present invention.

[0039] In terms of hardware implementation, the processing unit can be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, or a combination thereof. For firmware and / or software implementation, the method can be implemented by a module (such as a procedure, function, etc.) that performs the functions described herein.

[0040] The foregoing description of the disclosed embodiments is intended to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein, but should be given the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power distribution device, comprising Enclosures of power distribution devices; a power supply disposed in the housing, the power supply comprising a plurality of input conductors; as well as A plurality of sockets are disposed within the housing, each of the plurality of sockets having: a plurality of connectors including a first connector electrically connected to one input conductor and at least a second connector electrically connected to another input conductor; The associated residual current monitoring circuit comprises: at least one current sensor associated with the first connector and the at least second connector; as well as A differential detector is electrically connected to the at least one current sensor for determining the residual current.

2. The power distribution device of claim 1, wherein the at least one current sensor comprises a first current sensor and a second current sensor, the first current sensor being associated with the first connector to determine a first current detection output; The second current sensor is associated with at least a second connector to determine a second current detection output; The differential detector determines a current difference between the first current sense output and the second current sense output.

3. The power distribution device according to claim 2, wherein the plurality of input conductors include a first phase conductor and at least another phase conductor, a first connector of at least one socket among the plurality of sockets is electrically connected to the first phase conductor, and a second connector of the at least one socket is electrically connected to the another phase conductor.

4. The power distribution device according to claim 3, wherein the plurality of input conductors include a second phase conductor and a third phase conductor, and the second connector of the at least one socket is electrically connected to one of the second phase conductor or the third phase conductor.

5. The power distribution device according to claim 4, further comprising another socket among the plurality of sockets, the first connector of the other socket being electrically connected to the second phase conductor, and the second phase conductor being electrically connected to the third phase conductor.

6. A power distribution device according to claim 5, wherein the power supply is defined as a triangle configuration.

7. The power distribution device of claim 6, wherein at least the second phase conductor comprises a neutral conductor, and the power source is defined as any one of a single-phase power source or a multi-phase power source having a delta configuration or a wye configuration.

8. The power distribution device according to claim 1, wherein the plurality of input conductors include a first phase conductor, a second phase conductor, a third phase conductor and a neutral conductor, a first connector of at least one of the plurality of sockets is electrically connected to one of the first phase conductor, the second phase conductor and the third phase conductor, and a second connector of the at least one socket is electrically connected to the neutral conductor.

9. A power distribution device according to claim 7, wherein the power input is defined as a Y configuration or a delta configuration.

10. The power distribution device of claim 1, wherein the differential detector comprises a microcontroller; and each of the first current sensor and the second current sensor is a toroidal current transformer.

11. The power distribution device of claim 1, wherein each socket comprises a core having a surface defining a plurality of holes, a first power terminal being disposed in a first hole of the plurality of holes to define the first connector, and a second power terminal being disposed in a second hole of the plurality of holes to define the at least second connector.

12. The power distribution device according to claim 11, wherein the plurality of input conductors include a ground conductor, and each socket includes a ground terminal disposed in a third hole of the plurality of holes to define a third connector electrically connected to the ground conductor among the plurality of connectors.

13. A power distribution device according to claim 12, wherein the core of each socket is oriented so that each face is located in a common first plane, and each of the first current sensor and the second current sensor is mounted on at least one circuit board, and the at least one circuit board is oriented in at least a second plane parallel to the first plane.

14. The power distribution device according to claim 13, wherein the at least one circuit board comprises two circuit boards, and the first current sensor and the second current sensor are mounted on different circuit boards.

15. The power distribution device of claim 12, wherein the core of each socket is oriented so that each face is located in a common first plane, and each of the first current sensor and the second current sensor is mounted on at least one circuit board, and the at least one circuit board is oriented in at least a second plane perpendicular to the first plane.

16. The power distribution device according to claim 15, wherein the at least one circuit board comprises two circuit boards, and the first current sensor and the second current sensor are mounted on different circuit boards.

17. The power distribution device of claim 1, wherein the plurality of power outlets define a module, each power outlet in the module being connected together.

18. The power distribution device of claim 17, wherein each power outlet of the module includes a terminal having a hole formed therein, the module including a circuit conductor extending through the hole of each terminal to connect the plurality of power outlets together.

19. The power distribution device of claim 1, further comprising at least one voltage detection network.

20. The power distribution device according to claim 1, wherein the residual current monitoring circuit monitors AC current in the range of 42-2000 Hz.

21. The power distribution device of claim 1, further comprising an input power line and an input residual current monitor associated with the input power line.

22. The power distribution device of claim 1, wherein the at least one current sensor comprises a first current sensor associated with the first connector to determine a first current detection output; and a second current sensor associated with each of the first connector and the at least second connector.

23. The power distribution device of claim 1, wherein the at least one current sensor comprises a current sensor associated with each of the first connector and the at least second connector.

24. A socket module, comprising: at least one circuit board; a first pair of current sensors mounted on the at least one circuit board; at least a second pair of current sensors mounted on the at least one circuit board; at least one differential detector mounted on the at least one circuit board for determining a difference between current sense outputs of each pair of current sensors; as well as a first power outlet associated with the first pair of current sensors; as well as At least a second power outlet is associated with the at least a second pair of current sensors.

25. The socket module of claim 24, wherein the differential detector comprises a microcontroller; and each of the first pair of current sensors and the at least second pair of current sensors comprises a toroidal current transformer.

26. The socket module according to claim 25, wherein each of the first power socket and the at least second power socket comprises a core having a surface defining a plurality of holes, wherein at least a first power terminal is disposed in a first hole of the plurality of holes, the first power terminal being associated with one current sensor in an associated pair of current sensors; and a second power terminal is disposed in a second hole of the plurality of holes, the second power terminal being associated with the other current sensor in the associated pair of current sensors.

27. The socket module of claim 26, wherein the core of each socket is oriented so that a face of each core lies in a common first plane, and at least one circuit board is oriented in at least a second plane parallel to the first plane.

28. The socket module of claim 27, wherein the at least one circuit board comprises two circuit boards, the associated pair of current sensors being mounted on different circuit boards.

29. The jack module of claim 26, wherein the core of each jack is oriented so that a face of each core lies in a common first plane, and at least one circuit board is oriented in at least a second plane perpendicular to the first plane.

30. The socket module of claim 29, wherein the at least one circuit board comprises two circuit boards, the associated pair of current sensors being mounted on different circuit boards.

31. A method for detecting residual current in a power distribution device, the method comprising: Provide residual current monitors for multiple power sockets; as well as A leakage current of at least one socket is detected by the residual current monitor as a difference between a supply current and a return current of each socket.

32. The method of claim 31 , wherein monitoring at a socket of the plurality of sockets comprises: Associating a first connector of the socket with a first current sensor and generating a first current detection output of the first current sensor; associating a second connector of the socket with a second current sensor and generating a second current detection output of the second current sensor; as well as A difference between the first current sense output and the second current sense output is determined.

33. The method of claim 32, wherein associating the first connector of the receptacle with a first current sensor comprises: associating a first power terminal of the socket with a toroidal current transformer; and Wherein associating the second connector of the socket with the second current sensor comprises associating the second power terminal of the socket with a toroidal current transformer.

34. The method according to claim 32, further comprising: detecting a load coupled to a first outlet of the plurality of outlets, and detecting a load coupled to at least a second outlet of the plurality of outlets; detecting current leakage of the plurality of sockets; as well as Identifying which of the first socket and the at least second socket has a current leakage.

35. A socket module for a PDU, the socket module comprising: a core having a face defining a plurality of apertures; a first power terminal disposed within a first hole of the plurality of holes; a second power terminal disposed within a second hole of the plurality of holes; a first current sensor associated with the first power terminal; as well as A second current sensor is associated with the second power terminal.

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