Circuit breaker forensics for power distribution units

Abstract

Power distribution systems and methods are disclosed in which a power distribution unit (PDU) is provided with an overcurrent protection device and per-receptacle current sensing means at each of a plurality of electrical receptacles of the PDU. The described embodiments enable identification of an electronic device connected to a particular socket or electronic device that may have caused the overcurrent protection device to trip. A socket identification method in a PDU having a plurality of electrical sockets includes detecting whether a peak current or a half-cycle root-mean-square (RMS) current at each socket has exceeded a selected threshold prior to occurrence of a trip event associated with the overcurrent protection device.

Description

Technical Field

[0001] The present disclosure relates generally to power distribution units and, more particularly, to power distribution units that provide methods and systems for detecting electrical outlets that cause overcurrent protection device (OCPD) tripping events. Background Art

[0002] A conventional power distribution unit (PDU) is a combination of several electrical outlets (also called receptacles) that receive power from a power source and distribute it to one or more independent electronic devices. Each such PDU assembly has a power input that receives power from one or more power sources via the PDU's power cord. The electrical outlets can be used to provide power to one or more electronic devices plugged into the PDU outlets. PDUs are used in many applications and situations, such as, for example, in or on electronic equipment racks. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] A further understanding of the nature and advantages of the present technology may be achieved by reference to the following drawings, in which similar components or features may have the same reference numerals.

[0004] Figure 1 is a diagram of an exemplary power distribution unit (PDU).

[0005] Figure 2A is an example single-line wiring diagram for a basic rack PDU.

[0006] Figure 2B It is connected to the power input and the network Figure 1 Example wiring diagram for a PDU.

[0007] Figure 2C yes Figure 1 Another exemplary wiring diagram for a PDU.

[0008] Figure 3 is used for Figure 1 A block diagram of an exemplary embodiment of an outlet module in a PDU.

[0009] Figure 4 is used for Figure 1 A block diagram of another exemplary embodiment of a plurality of outlet modules within a PDU.

[0010] Figure 5 is used for Figure 1 A block diagram of another exemplary embodiment of multiple outlet modules in a PDU.

[0011] Figure 6 is a flow chart of an exemplary method for trip detection forensics.

[0012] Figure 7is a flow chart of another exemplary method for trip detection forensics.

[0013] Figure 8 and Figure 9 is used for Figure 1 Various exploded perspective views of exemplary embodiments of an outlet module in a PDU.

[0014] Figure 10 is a flow chart of an exemplary method for monitoring a plurality of electrical receptacles of an electrical distribution device and identifying whether the receptacles caused a trip event associated with an overcurrent protection device of the electrical distribution device.

[0015] Figure 11 is an example of the current sensor output and the corresponding calculated 1 / 2 cycle RMS output. DETAILED DESCRIPTION

[0016] This description provides an example and is not intended to unnecessarily limit the scope, applicability or configuration of the present invention. More specifically, the following description will provide a description for realizing an embodiment of the present invention for those skilled in the art. Various changes can be made to the function and arrangement of elements. Therefore, various embodiments can appropriately omit, replace and / or add various programs or parts. For example, various aspects and elements described about certain embodiments can be combined in various other embodiments. It should also be understood that the following systems, devices and components can be parts of larger systems individually or collectively, and wherein other programs can take precedence over their application or otherwise modify their application.

[0017] When using a Power Distribution Unit (PDU), an Overcurrent Protection Device (OCPD) may trip, and the customer is interested in knowing why this happened, i.e., which electronic device attached to a specific PDU outlet caused the OCPD to trip so that it can be replaced quickly to minimize downtime and without having to test every electrical outlet in the PDU.

[0018] An embodiment of the disclosed technology is directed to a PDU having the ability to determine which of a plurality of electronic devices connected thereto may have caused a trip event associated with an OCPD of the PDU. The described embodiment achieves this by using current sensors on a per-outlet basis to enable detection of the specific electronic device that caused the trip event, thereby minimizing data center downtime and / or mitigating or eliminating electrical hazards. In one example, this is achieved by identifying a condition, such as a corresponding current sensor of an electrical outlet measuring a current that is subsequently used (e.g., by a microcontroller) to calculate a current characteristic that exceeds a specified threshold. In another example, if no outlet meets the condition, the trip cause will not be reported. This may occur when the combined current of the electronic devices on a single electrical branch exceeds the OCPD trip current, but no individual electronic device current exceeds the OCPD trip current. In yet another example, if multiple electrical outlets meet the condition, the identified electrical outlet with the highest current characteristic will be reported as the electrical outlet that caused the OCPD trip event.

[0019] Figure 1 An exemplary embodiment of a PDU 10 is shown in FIG, which includes a housing 12 having a plurality of outlets 20 (also referred to as "receptacles," "outlets," "electrical outlets," or "power outlets") mounted therein to supply power to individual assets or equipment (e.g., assets used in the operation of a data center). The asset can be mounted in an equipment rack and appropriately plugged into one of the outlets 20 of the PDU. Thus, the PDU 10 can be configured for vertical or horizontal mounting. In order to supply and distribute power to the connected assets via the outlets 20, the PDU 10 is configured to internally receive power input. As shown, the PDU can include an internally wired input power cord 30 that extends outwardly and terminates in an associated plug 32 for connection to a power source in a conventional plug and jack connection. Alternatively, the PDU 10 can be configured to be internally hardwired to an external power source. The PDU 10 can include a visual display portion 40 to display monitored information, such as an indication of which outlet of the PDU has detected an excessive current. The visual display can display other information, such as, for example, power consumption, voltage, and / or current based on each outlet. Alternatively or additionally, the PDU 10 can be coupled to an external display to convey such information. The outlets 20 can be grouped and configured to define one or more outlet modules 200, as described herein. For example, each outlet module 200 (also referred to as a "dashboard") of the illustrated PDU 10 includes six outlets 20a-20f. However, it should be understood that other embodiments of the outlet module 200 can include fewer or more outlets 20, so long as at least one outlet is configured with a current monitoring circuit and an overcurrent protection device in the manner described herein.

[0020] In existing embodiments (e.g., Figure 2A (shown in Figure 1, which depicts a simplified two-branch single-line diagram), without the circuit breaker forensics described in this application, determining which electronic device connected to one of these outlets was the cause of the trip event is a manual, time-consuming process. For example, such manual determination typically includes:

[0021] (1) Turn off or disconnect each electronic device connected to the outlet;

[0022] (2) Turn on the circuit breaker; and

[0023] (3) Turn on each electronic device in the electronic equipment (or connect each electronic device to the PDU) in a sequential manner until the faulty device is located.

[0024] Furthermore, if the electronic device failure is a transient event, such manual procedures may not reliably identify the failed electronic device.

[0025] For example, Figure 2B and Figure 2C The disclosed embodiments described in the context of overcome the shortcomings associated with the above-mentioned manual determination by implementing circuit breaker forensics, which uses a current sensor at each electrical outlet to measure the current passing therethrough and automatically determine whether certain current characteristics have exceeded predetermined thresholds.

[0026] exist Figure 2B An exemplary system 2 is shown in a block diagram of that includes a PDU 10 to provide power to one or more associated computing assets, such as, for example, devices of a computer network 4, which may include computing and processing assets within an enterprise data center. The PDU 10 can communicate with a data center operator or networking application, such as, for example, a power management application 6, via a computer network 4 using a workstation or other device used in the management of a data center or other enterprise, and the PDU is connected to the network 4. As schematically shown, the outlet module 200a of the PDU 10 is wired and configured with an overcurrent protection device 100a that acts as a fuse (or ordinary circuit breaker) and breaks down or creates an open circuit when a measured current exceeds a threshold value due to one or more electronic devices connected to the outlets 20a-20n of the module 200a. This tripping event cuts off power to all electronic devices connected to the outlets 20a-20n. In Figure 2BIn the diagram, the thick wires (e.g., from the input power meter 161 to each OCPD and intelligent power module) represent high voltage, while the thin wires (e.g., to / from the network card 60) are low voltage connectors. In some embodiments, each of the modules 200a, 200b, 200c is wired and configured with its own overcurrent protection device 100a, 100b, 100c. In other embodiments, more than one module is connected to a single OCPD.

[0027] Figure 2C An exemplary single-line wiring diagram of a switch rack PDU implemented according to the disclosed technology is shown. As shown, each group of outlets (20a, ..., 20n, which correspond to the devices plugged into the switch rack PDU) is connected to a corresponding voltage sensor 120 ("VS") and circuit breaker 100a ("OCPD"). Each outlet (e.g., 20a) is configured with its own relay (e.g., 140a) ("RLY") and current sensor (e.g., 110a) ("CS"), which enables current monitoring and switching for each outlet. The PDU further includes a microcontroller ("P"), a display ("LCD"), and network communication capabilities 60 ("COM").

[0028] Embodiments of the disclosed technology are capable of effectively identifying electronic devices that may have caused a trip event. In order to determine which electronic device connected to the electrical outlets 20a-20n may have caused a trip event, the embodiment of the PDU 10 is configured to provide current sensing on a "per-outlet" basis, for example, each outlet has an associated current sensor 110. In one example, the current sensor 110 is configured to measure a signal representing the current, which is then processed by a microcontroller associated with the current sensor 110 (in the example of FIG. Figure 2B Not shown in Figure 2C In another example, the current signal from the current sensor 110 is sampled by the μP, for example 64 times per AC cycle, and the measurements over the past few seconds are stored for analysis by a forensic algorithm that may be implemented in the microcontroller.

[0029] In some embodiments, when the PDU detects a circuit breaker trip (e.g., OCPD 100a indicates a trip event), the forensic algorithm is configured to determine the electronic device that caused the trip event by examining a storage buffer of instantaneous current measurements. In one example, the current measurements are generated by sampling a signal (representing current) from a current sensor. In some scenarios, the forensic algorithm calculates a 1 / 2 AC cycle RMS current value from a storage buffer associated with each electronic device connected to each outlet 20a-20n. In other scenarios, the forensic algorithm identifies a peak instantaneous current measurement from a storage buffer associated with each electronic device connected to each outlet 20a-20n. In one example, the 1 / 2 AC cycle RMS current value from the storage buffer can be used when the circuit breaker trips within as little as 1 / 2 AC power cycle.

[0030] For the embodiments described herein, the microcontroller is configured to transmit the detection result of a current characteristic exceeding a threshold value (e.g., 1 / 2 AC cycle RMS current or peak current) to a display 40, or to transmit the detection result of the current characteristic to a networked device or operator via the network 4 so that appropriate personnel can resolve the problem. Accordingly, the PDU 10 includes an LCD display, one or more LED indicators, and / or a network interface card 60 for communicating with devices on the network 4. Each outlet 20a-20n is further associated with a voltage sensor 120, as well as a relay 140 and a relay driver 150, and it should be noted that the relay 140 and relay driver 150 are optional.

[0031] In some embodiments, LED indicators located next to one or more electronic devices connected to outlets 20a-20n flash and / or change color to indicate that those devices have lost power due to a tripped circuit breaker. Contrasting colors and / or flashing rates / patterns are used to indicate the specific electronic device that caused the circuit breaker to trip. Additionally or alternatively, a textual indication of the tripped circuit breaker and the faulty electronic device is displayed on the PDU's LCD display. In some embodiments, the LEDs are controlled by a first microcontroller that is different from a second microcontroller that controls the LCD display.

[0032] In some embodiments, the PDU transmits event notifications of circuit breaker trip events and / or the outlets that caused the trip events via Simple Network Management Protocol (SNMP) traps. In other embodiments, current measurements associated with each outlet and / or circuit breaker trip status can be remotely polled using SNMP or JavaScript Object Notation (JSON) formatted messages. In still other embodiments, the PDU can be configured to support a web browser that can be used to determine circuit breaker status and current measurements.

[0033] In some embodiments, the PDU is configured to convey the following information:

[0034] - an indication that the OCPD has tripped and / or corresponding details,

[0035] - Indication of suspect outlets and / or current characteristics exceeding thresholds, and

[0036] - Captured waveform of the trip event.

[0037] The information listed above may be transmitted, for example, via the following means:

[0038] - a display 40,

[0039] - to the network device and / or the operator's network card 60 at the network 4,

[0040] - a network server,

[0041] -SNMP queries and / or traps,

[0042] - Command Line Interface (CLI), such as telnet or ssh,

[0043] - USB serial access and CLI to local carriers, and / or

[0044] -LED blinking pattern next to the socket.

[0045] Figure 3 A block diagram of an exemplary outlet module 200 is shown in which each outlet current sensor 110 is electrically connected to an overcurrent protection device (OCPD) 100 and an electrical power source or power supply 112 via a corresponding conductor of a plurality of conductors. The power supply 112, which may be external to the PDU 10, is connected to the PDU 10 via its power cord and transmits one or more phases of 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 supply 112. Each outlet 20a-20h also includes an associated current sensor 110 that can measure the current of the electrical outlet. In some embodiments, the outlet modules described herein may include a voltage sensing network 120 to determine the voltage at each outlet 20a-20h and other power related parameters described herein. Each outlet 20a-20h is also connected to ground GND in the power supply 112, but is not connected to the ground GND in the power supply 112. Figure 3 These connections to the sockets 20a-20h are not shown. Figure 2B different, Figure 3 The illustrated embodiment does not include relays or relay drivers associated with each electrical outlet 20a-20h.

[0046] Figure 3 Detailedly shown in FIG. 1 is an exemplary embodiment of a module (or dashboard) 200 electrically connected to two conductors L1, L2 of a power source 112. Figure 3 In the illustrated line-to-line distribution configuration of the PDU, the first conductor L1 can be connected to one phase of AC power in the power source 112, and the conductor L2 can be connected to the second phase of AC power in the power source 112. Thus, the outlet module 200 can be configured such that each outlet 20 has one connector 22a electrically connected to the first conductor L1, which carries the first phase line power, and another connector 22b electrically connected to the second conductor L2, which carries the second phase line power. Similarly, Figure 3 As shown, an overcurrent protection device (OCPD) 100 is connected between the power source 112 and the module 200, and spans L1 and L2. In this example of a single-phase power source, the OCPD includes a single double-pole ganged circuit breaker connected to L1 and L2. In this context, L1 or L2 can be tripped (or opened) independently, but the OCPD 100 disconnects (or breaks) both conductors L1 and L2.

[0047] Alternatively, in a line-to-neutral distribution configuration of the PDU ( Figure 3 (not shown), the conductors can be connected to different phases of the power source 112. Thus, for example, each receptacle 20 of the module 200 can have one connector 22a electrically connected to a first conductor L1, which carries the first phase line power, and another connector 22b electrically connected to a second conductor L2, which is connected to the neutral line. In this example, a single-pole OCPD is used for each phase of the multi-phase configuration of the power source 112.

[0048] In some embodiments, the current signal is continuously measured by a current sensor and sampled by a processor on the network card (i.e., a network processor) to determine the current characteristics. As described herein, the network processor continuously performs a 1 / 2 cycle RMS current calculation operation or a peak determination operation based on the samples in the buffer. After a trip event associated with the corresponding OCPD is detected, the most recent sample in the buffer before the trip event is examined. In one example, a trip event is detected when the voltage associated with each electrical outlet connected to the OCPD drops below a threshold, such as 75% of the nominal voltage value or within a range of 65% to 85% of the nominal voltage value. In one example, the specified threshold for current sensor detection can be set to 125% of the OCPD rating.

[0049] In some embodiments, a 1 / 2 cycle root mean square (RMS) function may be used for the current calculations performed by the microcontroller. In other embodiments, the peak amplitude may be used.

[0050] In the case of a multi-phase power source 112, the PDU 10 may have Figure 4 and Figure 5 Delta or star power output wiring configuration as shown. Figure 4 As shown, the multi-phase power source 112 is connected to the PDU in a three-phase delta configuration. Figure 4 The PDU 10 of FIG. 1 shows three outlet modules 200 a , 200 b , 200 c , where the outlets 20 are electrically connected to conductors L1 , L2 , L3 in different combinations, and each OCPD 100 a , 100 b , 100 c spans two conductors entering the module.

[0051] In some embodiments, each module 200a, 200b, 200c includes a microcontroller 115a, 115b, 115c to receive the current signal from the corresponding associated current sensor 110a of each outlet 20. By sampling the signal from the current sensor 110a to generate a time-series current measurement value, this enables the microcontroller 115a, 115b, 115c to first determine the current characteristic (by calculating the 1 / 2 cycle RMS current or identifying the peak current) and then detect whether the current characteristic has exceeded a threshold for each outlet 20 of the corresponding associated module 200a, 200b, 200c.

[0052] Figure 5 1 shows a multi-phase power source 112 connected to a PDU in a three-phase wye configuration. Figure 5 The partial PDU shown in FIG. 1 shows the first connectors 22a of the outlets of three outlet modules 200a, 200b, and 200c, which are electrically connected to conductors L1, L2, and L3, respectively, with corresponding overcurrent protection devices (OCPDs) 100a, 100b, and 100c therebetween. The associated current sensor 110a of the first connector 22a in each outlet 20 detects the current flowing through the outlet. Similarly, each outlet module 200a, 200b, and 200c includes a microcontroller 115a, 115b, and 115c to receive the current sensing output from the corresponding associated current sensor 110a of each outlet 20a-20h. The corresponding current sensor 110a continuously measures the current signal, which can be used to determine whether the associated outlet is the cause of a trip event for the corresponding OCPD.

[0053] In some embodiments, Figure 3 and Figure 4 A double pole "ganged" OCPD (or circuit breaker) in the can be implemented using part # J61-X0-26-127-K3D-D3 manufactured by Carling Technologies, and a single pole circuit breaker (e.g., in Figure 5) can be accomplished using part #J62-X0-26-128-K3D-D3 manufactured by Carling Technologies.

[0054] In the above embodiment, each microcontroller on each outlet module (or dashboard) is configured to sample the current signal, use the samples to determine the current characteristics, compare the current characteristics to a threshold value, and report the results to the main controller (e.g., Figure 2B Alternatively, each dashboard may transmit the current characteristics to the main controller. In other embodiments, the main controller is configured to receive the current signal and perform sampling operations, determination operations, and comparison operations.

[0055] Figure 6 shows that the Figure 2B Flowchart of an exemplary method for trip detection forensics implemented by the output module 200a in . As shown therein, the outlet (dashboard) measures voltage and current, and continuously updates the voltage and current waveforms respectively to always store the most recent 128 samples (corresponding to 2 AC cycles). In this article, the measured values ​​include 64 samples per AC cycle generated using an analog-to-digital converter (ADC). In one example, the microcontroller for the dashboard is configured to calculate the average voltage and current RMS values ​​over 1 second. The dashboard continuously scans for faults in the AC mains voltage by: (a) determining a "fault voltage threshold", which is calculated as the larger of 20V or 25% of the most recently measured 1-second RMS value, and (b) indicating that the voltage has failed if any of the following three conditions are met:

[0056] (i) Check a single voltage sample to determine if 16 consecutive samples are below the fault voltage threshold, or if the difference between 2 consecutive samples is below a threshold of 16 consecutive samples, where the threshold is calculated as the greater of 2V or 5% of the most recently measured 1-second RMS value. For example, if the most recently measured 1-second RMS value is 25V, then 5% x 25V = 1.25V, and the threshold is calculated as max(2V, 1.25V) = 2V; or

[0057] (ii) checking for the presence of zero crossings (e.g., using a voltage phase-locked loop (PLL)) to determine if two zero crossings are not present at the expected time; or

[0058] (iii) Check the half-cycle RMS voltage value to determine whether the half-cycle RMS is lower than the fault voltage threshold.

[0059] Once it is determined that the voltage supply has failed (i.e., one or more of the three conditions above are met), which in turn indicates an OCPD trip event, the cluster microcontroller determines the likely cause of the trip by:

[0060] (i) Wait for another 16 samples (1 / 4 AC period);

[0061] (ii) for each outlet, determining the highest 1 / 2 cycle RMS current value, for example, by scanning the signal from the current sensor;

[0062] (iii) The designated outlet is a potential tripping cause if:

[0063] (a) The highest 1 / 2 cycle RMS current determined exceeds 125% of the OCPD rating (i.e., an overload condition), or

[0064] (b) at least two current samples fully saturate the ADC (i.e., a short circuit condition). In one example, fully saturating the ADC corresponds to a sample taking a maximum value within the data range of the sample;

[0065] (iv) If more than one receptacle can be considered as a potential tripping cause, the receptacle with the highest 1 / 2 cycle RMS is selected; and

[0066] (v) After a suspect outlet has been identified, a snapshot of the current and / or voltage waveform of the outlet is created.

[0067] In this embodiment, the microcontroller on the dashboard reports the socket ID of the suspect socket, the determined 1 / 2 cycle RMS current value and the waveform to the main controller.

[0068] In some embodiments, the dashboard may implement the above algorithm using peak current values ​​as the current characteristic (instead of 1 / 2 cycle RMS current values).

[0069] Figure 7 It shows that the main controller (e.g. Figure 2B A flowchart of an exemplary method for trip detection forensics implemented by a network card (e.g., a network card 60 in FIG. ) is provided. As shown therein, the master controller retrieves the RMS voltage value of each outlet every second. If the voltage of all outlets connected to the circuit breaker is less than 75% of the phase voltage of the outlets supplying the circuit breaker, the master controller will consider the OCPD to be tripped or disconnected. If this condition is not met, the OCPD will be considered closed, and any connected outlets that were previously disconnected due to the disconnected OCPD state will be connected. In some embodiments, connected outlets are only connected after receiving an explicit reset command or after one or more administrator intervention actions have occurred.

[0070] At this point, the master controller searches the outlet strips (or panels) connected to a given circuit breaker for reported trip causes. The outlet with the highest reported current characteristic is reported to the user as the most likely cause of the trip. In one example, reporting can be performed via a web-based graphical user interface (GUI) or command line interface (CLI). In another example, JSON-RPC is used. Finally, the waveform associated with the outlet that may have caused the trip is retrieved.

[0071] Figure 8 and Figure 9 Two exploded views of an exemplary module 200' are shown, which is equipped with six sockets 20'a-20f, which are disposed within a module tray or housing 230 and engage with a toroidal current sensor 110a. The current sensor 110a is mounted such that its corresponding output lead 102a is mounted to a printed circuit board PCB 240. Thus, the sensor 110a is disposed between the socket core 220 and the PCB 240, and more specifically, between the module housing 230 and the PCB 240.

[0072] By providing current monitoring and overcurrent protection as described herein to embodiments of the PDU 10, additional fault isolation information can be provided to maintenance personnel, allowing them to correct the fault condition and restore the affected IT equipment with minimal impact on system uptime. In one example, the following isolation procedure can be implemented to restore power to all electronic devices except the faulty electronic device:

[0073] (1) When a trip event occurs and a faulty electronic device is identified, the relay that controls the power to the faulty device is disconnected;

[0074] (2) The circuit breaker is reset to restore power to all electronic equipment except the faulty equipment;

[0075] (3) The faulty equipment is disconnected and replaced / repaired; and

[0076] (4) Restore power to the replaced / repaired equipment by closing the relay using the PDU's local keypad / LCD or remotely via the PDU's web browser interface.

[0077] In some embodiments, and like the PDU of U.S. Patent No. 9,952,261, embodiments of the PDU 10 may be configured with "Per Outlet Power Sensing" or ("POPS"), which refers to the concept of detecting the load coupled to each outlet and monitoring the power consumption at each outlet. Thus, because the outlet module's microcontroller 115 (e.g., Figure 3 、 Figure 4 and Figure 5The receiving module 200 receives current information and voltage information for each socket 20, so that the load current and various power-related metrics can be calculated for each socket, and the information can be reported to the network power manager 6 or other network-connected computers or devices via the network 4.

[0078] In some embodiments, the PDU may be configured with latching relays.

[0079] In some embodiments, each electrical outlet 20 can be a metered outlet (each outlet having one or more sensors, each sensor being associated with a display configured to display both a status and a reading corresponding to a measurement) or a switched outlet (which can be switched on or off to selectively control the flow of current through it, and in one example, can be switched by software).

[0080] In some embodiments, the microcontroller 115 can be connected to a communication bus (such as an RS485 bus, an I2C bus, or an SMBus). Embodiments of the PDU 10 can include a network interface card (e.g., a network card 60) to report over the network 4. These measurements can be made by sensors on metered and switched outlets. These measurements can be received by an external system that collects the outlet information that provides it with data and is used to determine metrics or provide information as described above.

[0081] In some embodiments, each switched electrical outlet in a PDU can be collectively configured as latching or non-latching, and the PDU is configured with a surge (or inrush) protector, which is a configurable minimum (delay) interval between two electrical outlets of the PDU being switched on. The purpose of the surge protector is to avoid overloading the outlet or OCPD due to the combined surge current of many loads switched on at the same time. In the case of a latching relay, the relay has been configured to maintain its previous state upon loss of power, and the surge protector is ineffective when power to the unit is restored. For PDUs with multiple outlets, the surge protector can switch on outlets from each outlet at a time. For outlets with two or three phases, the surge protector can switch on multiple outlets at a time, and in various combinations.

[0082] An embodiment of the disclosed technology provides a power distribution device comprising: a housing; a power receptacle; a plurality of electrical outlets, wherein each of the plurality of electrical outlets (a) is suitable for supplying power to an associated electronic device and (b) includes an associated current sensor; at least one overcurrent protection device; and at least one processor coupled to the at least one overcurrent protection device and each associated current sensor, the at least one processor being configured to receive a signal representing current from each associated current sensor, calculate a current characteristic of each associated current sensor based on the signal, detect a trip event associated with the at least one overcurrent protection device, and determine whether at least one calculated current characteristic exceeds a selected threshold before detecting the trip event.

[0083] In some embodiments, the processor is a microcontroller on a meter board (e.g., Figure 2C μP in , which is different from a network interface card (e.g., Figure 2B In other embodiments, the processor is a network processor on a network interface card (NIC). In other embodiments, the processor is a microcontroller on a NIC that also includes a network processor.

[0084] In some embodiments, upon determining that the at least one calculated current characteristic exceeds a selected threshold, the at least one processor is further configured to correlate the at least one calculated current characteristic with at least one of a corresponding associated current sensor or its associated electronic device.

[0085] In some embodiments, when the at least one processor determines that the corresponding current characteristic exceeds a selected threshold before a tripping event is detected, the at least one processor is further configured to identify a suspicious electrical outlet or a suspicious electronic device thereof corresponding to the corresponding current characteristic, and transmit an identifier associated with the suspicious electrical outlet to a location remote from the electrical distribution device.

[0086] In some embodiments, when the at least one processor determines that two or more corresponding current characteristics exceed a selected threshold before a tripping event is detected, the at least one processor is further configured to identify two or more suspicious electrical sockets or their suspicious electronic devices corresponding to the two or more corresponding current characteristics, and transmit an identifier associated with the associated electrical socket having the highest value of the measured corresponding current characteristic among the two or more suspicious electrical sockets to a location remote from the electrical distribution device.

[0087] In some embodiments, the at least one processor is further configured to transmit a waveform capture corresponding to a signal from at least one of the associated current sensors to a location remote from the power distribution device.

[0088] In some embodiments, when the at least one processor determines that each of the corresponding current characteristics does not exceed a selected threshold, the at least one processor is further configured to transmit a message to a location remote from the electrical distribution device indicating that the absence of any one of the plurality of electrical outlets is the sole cause of the tripping event.

[0089] In some embodiments, the power distribution apparatus includes a voltage sensor, wherein detecting a trip event associated with at least one overcurrent protection device is based on a signal representative of a voltage from the voltage sensor.

[0090] In some embodiments, calculating the current characteristic is based on sampling the signal from each associated current sensor.

[0091] In some embodiments, a trip event associated with at least one overcurrent protection device corresponds to a voltage at at least one of the plurality of electrical outlets being less than a selected percentage or range of percentages of a voltage at the power outlet. In one example, the selected percentage is 75%. In another example, the selected percentage range is from 65% to 85%.

[0092] In some embodiments, at least one electrical outlet of the plurality of electrical outlets is a switched electrical outlet that can be switched on or off to selectively control electrical current passing therethrough.

[0093] In some embodiments, the at least one processor is further configured to identify a suspicious electrical socket corresponding to a corresponding current characteristic, switch the suspicious electrical socket to an off state, maintain the suspicious electrical socket in the off state, and switch the suspicious electrical socket to an on state upon determining that an external reset command or an administrator verification message has been received.

[0094] In some embodiments, the current characteristic represents a half-cycle root mean square (RMS) current or a peak current.

[0095] Embodiments of the disclosed technology further provide a method of monitoring a plurality of electrical outlets of a power distribution device, each of the plurality of electrical outlets being adapted to provide power to an associated electronic device and including an associated current sensor. Figure 10 As shown, method 1000 includes, at operation 1010 , receiving a signal representative of current from each associated current sensor.

[0096] Method 1000 includes calculating a current characteristic of each associated current sensor based on the signal at operation 1020. In one example, the signal is sampled, and the current characteristic is determined based on the samples.

[0097] Method 1000 includes, at operation 1030 , detecting a trip event associated with at least one overcurrent protection device.

[0098] Method 1000 includes, at operation 1040 , determining whether at least one calculated current characteristic exceeds a selected threshold value prior to detecting a trip event.

[0099] In some embodiments, method 1000 includes the following operations: determining that a corresponding current characteristic exceeds a selected threshold value before a trip event is detected, identifying a suspect electrical outlet corresponding to the corresponding current characteristic, and providing a perceptible indication of the suspect electrical outlet on the power distribution device. In one example, the perceptible indication is provided on a display of the power distribution device. In another example, the perceptible indication is provided via one or more light emitting diodes (LEDs) on the power distribution device.

[0100] In some embodiments, the current characteristic represents half-cycle root mean square (RMS) current. Figure 11 An example of a current sensor output and calculated 1 / 2 cycle RMS is shown. In other embodiments, the current characteristic represents peak current.

[0101] Those skilled in the art will appreciate that the various exemplary logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments disclosed herein may be implemented as electronic hardware, computer software, firmware, or a combination thereof. To clearly illustrate this interchangeability, various exemplary components, blocks, modules, circuits, and steps have been described above in terms of their functionality. Whether such functionality is implemented as hardware, software, and / or firmware depends on the specific application and the design constraints imposed on the overall system. A skilled person may implement the described functionality in different ways for each specific application, but such implementation decisions should not be interpreted as resulting in a departure from the scope of the present invention.

[0102] For hardware implementation, the processing unit may 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, these methods may be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described herein.

[0103] The foregoing description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily 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 invention. Therefore, the present invention is not limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power distribution device, comprising: shell; Power socket; a plurality of electrical outlets, wherein each electrical outlet of the plurality of electrical outlets (a) is adapted to provide power to an associated electronic device and (b) includes an associated current sensor; at least one overcurrent protection device; and at least one processor coupled to the at least one overcurrent protection device and each associated current sensor, the at least one processor configured to: receiving a signal representative of the current from each associated current sensor; calculating a current characteristic of each associated current sensor based on the signal; detecting a trip event associated with the at least one overcurrent protection device; as well as A determination is made as to whether at least one calculated current characteristic exceeds a selected threshold value prior to detection of the trip event.

2. The power distribution device according to claim 1, wherein: Upon determining that the at least one calculated current characteristic exceeds the selected threshold, the at least one processor is further configured to: The at least one calculated current characteristic is correlated with at least one of a corresponding associated current sensor or its associated electronics.

3. The power distribution device according to claim 1, wherein: When the at least one processor determines that the corresponding current characteristic exceeds the selected threshold before the trip event is detected, the at least one processor is further configured to: identifying a suspicious electrical outlet or a suspicious electronic device thereof corresponding to the corresponding current characteristics; and An identifier associated with the suspect electrical outlet is transmitted to a location remote from the electrical distribution device.

4. The power distribution device according to claim 1, wherein: When the at least one processor determines that two or more respective current characteristics exceed the selected threshold prior to detecting the trip event, the at least one processor is further configured to: identifying two or more suspicious electrical outlets or suspicious electronic devices thereof corresponding to the two or more respective current characteristics; and An identifier associated with the electrical outlet associated with the highest measured value of the corresponding current characteristic of the two or more suspect electrical outlets is transmitted to a location remote from the electrical distribution device.

5. The power distribution device of claim 3, wherein the at least one processor is further configured to: A waveform corresponding to the signal from at least one of the associated current sensors is captured and transmitted to the location remote from the power distribution device.

6. The power distribution device of claim 2, wherein when the at least one processor determines that each of the corresponding current characteristics does not exceed the selected threshold, the at least one processor is further configured to: A message is transmitted to a location remote from the electrical distribution device, the message indicating that the absence of any one of the plurality of electrical outlets is the sole cause of the trip event.

7. The power distribution device according to claim 1, further comprising: voltage sensor, Wherein detecting the trip event associated with the at least one overcurrent protection device is based on a signal representing a voltage from the voltage sensor.

8. The power distribution device of claim 1, wherein calculating the current characteristic is based on sampling the signal from each associated current sensor.

9. The power distribution device according to claim 1, wherein: The trip event associated with the at least one overcurrent protection device corresponds to a voltage at at least one of the plurality of electrical outlets being less than a voltage at the power receptacle by a selected percentage or range of percentages.

10. The power distribution device of claim 9, wherein the selected percentage is 75%.

11. The power distribution device of claim 9, wherein the selected percentage ranges from 65% to 85%.

12. The power distribution device of claim 1, wherein at least one of the plurality of electrical outlets is a switched electrical outlet that can be switched on or off to selectively control current flowing therethrough.

13. The power distribution device of claim 12, wherein the at least one processor is further configured to: identifying a suspect electrical outlet corresponding to the respective current characteristics; and Switch the suspect electrical outlet to an off state.

14. The power distribution device of claim 13, wherein the at least one processor is further configured to: maintaining the suspect electrical outlet in the off state; and Upon determining that an external reset command or an administrator authentication message has been received, the suspicious electrical outlet is switched to an on state.

15. The power distribution device of claim 1, wherein the current characteristic represents a half-cycle root mean square (RMS) current.

16. The power distribution device of claim 1, wherein the current characteristic represents a peak current.

17. A method for monitoring a plurality of electrical sockets of a power distribution device, each electrical socket of the plurality of electrical sockets being adapted to provide power to an associated electronic device and including an associated current sensor, the method comprising: receiving a signal representative of the current from each associated current sensor; calculating, using at least one processor of the power distribution device and based on the signal, a current characteristic of each associated current sensor; detecting, using the at least one processor, a trip event associated with at least one overcurrent protection device; as well as A determination is made using the at least one processor whether at least one calculated current characteristic exceeds a selected threshold value prior to detecting the trip event.

18. The method according to claim 17, further comprising: determining that the corresponding current characteristic exceeded the selected threshold value prior to detecting the trip event; identifying a suspect electrical outlet corresponding to the respective current characteristics; as well as A perceptible indication of the suspect electrical outlet is provided on the electrical distribution device.

19. The method of claim 18, wherein the perceptible indication is provided on a display of the power distribution device.

20. The method of claim 18, wherein the perceptible indication is provided via one or more light emitting diodes (LEDs) on the power distribution device.

21. The method of claim 17, wherein the current characteristic represents a half-cycle root mean square (RMS) current or a peak current.

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