Patent Application
20110113262
The present invention relates generally to high-current junctions, such as those that are susceptible to fire risks if they dissipate too much power, and more particularly to voltage sensors for such high-current junctions, to determine that the high-current junctions are apt to cause fire risks.
Data centers have large numbers of computing devices installed computing devices, usually in a space-efficient manner. One space-efficient manner to install large numbers of computing devices is to have a number of the computing devices installed within a data center rack. The computing devices may be blade computing devices, which can slide into corresponding slots of the data center rack. The blade computing devices are typically smaller in size than ordinary computing devices like desktop computers. A blade computing device can share a power supply with a number of other blade computing devices, to further minimize the space needs within the data center.
A data center rack includes an alternating current (AC) input, a power supply, a conductor, first and second high-current junctions, first and second voltage sensors, and a controller. The AC input receives AC power from AC mains. The power supply receives the AC power from the AC input and generates direct current (DC) power to provide to one or more data center rack components insertable within the data center rack. The conductor connects the AC input to the power supply. The AC input is removably connected to the conductor at the first high-current junction, where a high current passes from the AC input to the conductor. The power supply is removably connected to the conductor at the second high-current junction, where the high current passes from the conductor to the power supply. The first voltage sensor detects a first voltage at the first high-current junction, and the second voltage sensor detects a second voltage at the second high-current junction. The controller performs a predetermined action in response to one or more of the first voltage sensor detecting the first voltage being greater than a predetermined threshold voltage and the second voltage sensor detecting the second voltage being greater than the predetermined threshold voltage.
A system of an embodiment of the invention includes a high-current junction at which power connectors of two components are electrically connected, where a high current passes between the two components at the high-current junction. The system includes a voltage sensor to detect a voltage across the high-current junction. The system also includes a controller to perform a predetermined action in response to the voltage sensor detecting the voltage at the high-current junction being greater than a predetermined threshold voltage.
A method of an embodiment of the invention provides a first voltage sensor to detect a first voltage at a first high-current junction of a data center rack. The first high-current junction removably connects an AC input of the data center rack to a conductor of the data center rack, where a high current passes from the AC input to the conductor, and where the AC input is to receive AC power from AC mains. The method provides a second voltage sensor to detect a second voltage at a second high-current junction of a data center rack. The second high-current junction removably connecting the conductor to a power supply of the data center rack, where a high current passes from the conductor to the power supply. The power supply receives power from the AC input to generate DC power to provide to one or more data center rack components insertable within the data center rack. The method programs a controller of the data center rack to perform a predetermined action in response to one or more of the first voltage sensor detecting the first voltage being greater than a predetermined threshold voltage and the second voltage sensor detecting the second voltage being greater than the predetermined threshold voltage.
The drawings referenced herein form a part of the specification. Features shown in the drawing are meant as illustrative of only some exemplary embodiments of the invention, and not of all embodiments of the invention, unless otherwise explicitly indicated, and implications to the contrary are otherwise not to be made.
In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific exemplary embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized, and logical, mechanical, and other changes may be made without departing from the spirit or scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the embodiment of the invention is defined only by the appended claims.
As noted in the background section, a data center can include a data center rack in which a number of components, such as computing devices, may be installed as blades within corresponding slots of the data center rack, to share a smaller number of power supplies installed within the data center rack. A data center rack typically has a number of high-current junctions. A high-current junction is a location at which two components of the data center rack, such as power supplies, high-current conductors, and power inputs, are connected for high current to pass between the components. One such high-current junction may be the location at which a power supply is removably connected to a high-current conductor, whereas another high-current junction may be the location at which a power input is removably connected to a high-current conductor.
There are potential problems associated with such high-current junctions. First, the high-current junctions may be “hot plug” type junctions, in which components can be connected to the junctions without having to first remove power from the data center rack. Such “hot plug” high-current junctions are susceptible to having increased electrical resistance over time. Second, if a component makes a poor connection at the high-current junction, such as due to a user not properly seating the component within the data center rack, the high-current junction may also have increased electrical resistance. Such increased electrical resistance results in the amount of electrical power dissipated by the high-current junction also increasing, in the form of heat. The resulting increase in temperature can render the high-current junction susceptible to increased fire risks.
Conventionally, the increased temperature of a high-current junction is detected by using a temperature sensor, such as a thermocouple, or by an infrared camera. When the temperature sensor or the infrared camera indicates that the temperature at the high-current junction has increased beyond a preset temperature threshold, a user of the data center rack is notified to take corrective action, so as to prevent a fire from occurring at the high-current junction. However, existing temperature sensors and infrared cameras are relatively expensive. Because a data center may have a large number of data center racks, and each data center rack may have a large number of high-current junctions, installing temperature sensors or infrared cameras can be economically infeasible.
The inventors have developed a novel approach that by comparison does not employ expensive temperature sensors or infrared cameras to directly monitor the temperature at high-current junctions. Rather, this novel approach innovatively uses a voltage sensor at each high-current junction to directly detect the voltage at each junction. If the voltage at a high-current junction is greater than a preset threshold voltage, then a predetermined action is performed to alert a user of the data center rack to take corrective action to prevent a fire from occurring at the high-current junction in question.
The innovative approach developed by the inventors thus leverages an inventive insight that what should be detected is the underlying cause of the fire risk problem (i.e., increased voltage at the high-current junction as a result of the junction dissipating too much power), instead of detecting the resulting symptom of the fire risk problem (i.e., increased temperature). Voltage sensors are typically less expensive than temperature sensors and infrared cameras, and therefore can be economically feasible to employ in large numbers within a data center. The voltage sensors can thus be said to novelly indirectly monitor the temperatures of the high-current junctions, as opposed to directly monitoring the temperatures of the junctions, as is conventional.
The AC input 102 receives AC power from AC mains, such as may be achieved via hard-wiring to the AC mains, or via plugging a cord ending in a connector to a wall outlet. The power supply 104 receives the AC power from the AC input 102, and generates direct current (DC) power to provide to the blade computing devices 106 insertable within the data center rack 100. The blade computing devices 106 are examples of data center rack components that are insertable into corresponding slots of the data center rack 100, such as in a hot plug manner. The conductor 108 connects the AC input 102 to the power supply 104, and carries high current. For example, the amount of current passing on the conductor 108 may be sixty amps.
The AC input 102 is removably connected to the conductor 108 at the high-current junction 110, and the power supply 104 is removably connected to the conductor 108 at the high-current junction 112. High current thus passes from the AC input 102 to the conductor 108 at the high-current junction 110, and high current passes from the conductor 108 to the power supply 104 at the high-current junction 112. The high-current junctions 110 and 112 may be hot plug type junctions, where the AC input 102 and the power supply 104 may be connected without having to remove power from the data center rack 100 as a whole.
The high-current junctions 110 and 112 may be susceptible to having increased resistance over time. Furthermore, if the AC input 102 or power supply 104 makes a poor connection with the conductor 108 at its corresponding high-current junction, the electrical power dissipated by the high-current junction in question increases. In either case, the high-current junctions 110 and 112 are susceptible to having an increased temperature and causing a fire risk, as has been described above
A voltage sensor 208 detects the voltage over or at the high-current junction 202. Thus, for each high-current junction of
The controller 210 may be a service processor of the data center rack 100, in one embodiment. The controller 210 performs a predetermined action in response to the voltage sensor 208 detecting the voltage at the high-current junction 202 being greater than a predetermined threshold voltage. For instance, the controller 210 monitors the voltages stored within the memory locations of the memory 212. When any of these voltages exceeds the predetermined threshold voltage, the controller 210 performs the predetermined action. The predetermined action may be sounding an audible warning, displaying a visible warning, removing power from the high-current junction at which the voltage in question has been detected, or another type of action.
When the voltage 302 exceeds the first predetermined voltage threshold 304, the controller 210 performs the first predetermined action 306. If the voltage 302 continues to increase and then exceeds the second predetermined voltage threshold 308, the controller 210 next performs the second predetermined action 310. If the voltage 302 still continues to increase and exceeds the third predetermined voltage threshold 312, the controller 210 then performs the third predetermined action 314.
In this way, as the voltage 302 increases, different types of actions can be performed by the controller 210 in accordance with how close the voltage 302 is to causing an actual fire. For example, the first predetermined action 306 may be to display a visible warning, so that a user is notified that at some point in the future he or she should inspect the high-current junction at which the voltage 302 was detected. The second predetermined action 308 may be to sound an audible warning, so that a user is more urgently notified to inspect this high-current junction. The third predetermined action 314 may be to remove power from the high-current junction, corresponding to the situation that a fire is likely imminent as a result of the high voltage 302.
In conclusion,
It is finally noted that, although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This application is thus intended to cover any adaptations or variations of embodiments of the present invention. As such and therefore, it is manifestly intended that this invention be limited only by the claims and equivalents thereof.
