Abstract: Control systems for a multi-level diode-clamped inverter and corresponding methods include a processor and a digital logic circuit forming a hybrid controller. The processor identifies sector and region locations based on a sampled reference voltage vector V* and angle ?e*. The processor then selects predefined switching sequences and pre-calculated turn-on time values based on the identified sector and region locations. The digital logic circuit generates PWM switching signals for driving power transistors of a multi-level diode-clamped inverter based on the turn-on time values and the selected switching sequences. The control system takes care of the existing capacitor voltage balancing issues of multi-level diode-clamped inverters while supplying both active and reactive power to an IT load. Using the control system, one can generate a symmetrical PWM signal that fully covers the linear under-modulation region.

Abstract: A cooling system includes a heat exchanger having one or more rows of multiple flat tubes, louvered fins disposed between pairs of flat tubes, and special header tube connections to form a counter flow heat exchanger. Heat exchangers having multiple rows may be placed near or close to the server racks and may be in fluid communication with an outdoor heat exchanger having one or more rows. A single-phase fluid is pumped through a fluid circuit or loop, which includes the heat exchangers at the server racks and the outdoor heat exchanger. The single-phase fluid circuit including the heat exchangers at the IT racks may alternatively be in thermal communication with a water circuit that includes an outdoor fluid cooler. The flat tubes can be formed tubes with one or more channels, or extruded tubes with multiple channels. The heat exchangers include header tubes/connections, which facilitate easy fabrication and connection between rows and inlet/outlet, and lower the pressure drop.

Abstract: The cooling systems and methods of the present disclosure relate to cooling electronic equipment in data centers or any other applications that have high heat rejection temperature and high sensible heat ratio.

Abstract: An air curtain containment system and assembly for data centers forms an air curtain over the server cabinets thereby separating hot air in a hot aisle from cool ambient air. The air curtain containment system includes ducts which include a hot air intake section that receives hot air discharged from servers, which are disposed in server cabinets. The ducts include heat exchangers for cooling the hot air and at least one air curtain discharge section. A housing is coupled to a wall of the ducts, and includes a cooling edge device fan. The cooling edge device fan is disposed along the ducts, and is configured to draw the hot air for cooling through the heat exchangers. An air curtain fan assembly is disposed along the ducts. The air curtain fan assembly expels cold air through the air curtain discharge section, and thereby forms an air curtain over the server cabinets.

Abstract: Systems and methods for supplying power at a medium voltage from an uninterruptible power supply (UPS) to a load without using a transformer are disclosed. The UPS includes an energy storage device, a single stage DC-DC converter or a two-stage DC-DC converter, and a multi-level inverter, each of which are electrically coupled to a common negative bus. The DC-DC converter may include two stages in a unidirectional or bidirectional configuration. One stage of the DC-DC converter uses a flying capacitor topology. The voltages across the capacitors of the flying capacitor topology are balanced and switching losses are minimized by fixed duty cycle operation. The DC-DC converter generates a high DC voltage from a low or high voltage energy storage device such as batteries and/or ultra-capacitors. The multi-level, neutral point, diode-clamped inverter converts the high DC voltage into a medium AC voltage using a space vector pulse width modulation (SVPWM) technique.

Abstract: Electrical systems for providing uninterruptible power to a critical load. One electrical system includes a ring bus, multiple power blocks including one or more generators electrically coupled to the ring bus, and uninterruptible power supplies (UPSs) electrically coupled to the ring bus. In some aspects, the electrical system includes a UPS switchgear electrically coupled between the ring bus and the UPSs. In other aspects, the UPSs are electrically coupled together in parallel. Another electrical system includes a utility switchgear, UPS blocks electrically coupled together in parallel and electrically coupled to the utility switchgear via transformers, low voltage (LV) power blocks electrically coupled to the UPS blocks, and medium voltage (MV) switchgear electrically coupled to the UPS blocks via transformers. Each of the LV power blocks include one or more generators.

Abstract: The cooling systems and methods of the present disclosure involve modular fluid coolers and chillers configured for optimal power and water use based on environmental conditions and client requirements. The fluid coolers include wet media, a first fluid circuit for distributing fluid across wet media, an air to fluid heat exchanger, and an air to refrigerant heat exchanger. The chillers, which are fluidly coupled to the fluid coolers via pipe cages, include a second fluid circuit in fluid communication with the air to fluid heat exchanger and a refrigerant circuit in thermal communication with the second fluid circuit and in fluid communication with the air to refrigerant heat exchanger. Pipe cages are coupled together to allow for expansion of the cooling system when additional cooling capacity is needed. The fluid coolers and chillers are configured to selectively operate in wet or dry free cooling mode, partial free cooling mode, or mechanical cooling mode.

Abstract: An air flow distribution system for cooling server racks includes at least one server rack partially defining a hot aisle and a cold aisle, a first air foil disposed above the server rack, and a second air foil disposed above the first air foil. The first air foil and the second air foil are configured to receive air from the hot aisle, and to form turbulent wake patterns in the cold aisle partially defined by the server rack. The air flow distribution system may include a convex ceiling member above the second air foil. A corresponding method includes causing air to be directed between a first air foil disposed above a server rack and a second air foil disposed above the first air foil to form turbulent wake patterns in the cold aisle. An electrical enclosure assembly includes a receptacle and a cover member configured as an air foil.

Abstract: A power supply system includes an energy storage device electrically connected to a power grid, a power distribution assembly electrically connected to a load, and a power generation device electrically connected to the power distribution assembly. The energy storage device and the power grid are configured to supply electric power having a first voltage range to the power distribution assembly, which in turn, is configured to supply electric power having a second voltage range less than the first voltage range to the load. The energy storage device and the power generation device each are configured to at least temporarily supply a flow of electric power to the power distribution assembly when electric power from the power grid is interrupted such that a substantially uninterrupted flow of electric power is supplied to the load.

Abstract: A cooling assembly for cooling server racks includes a server rack enclosure sub-assembly that includes at least one panel member defining a volume for receiving one or more server racks having a front portion and a rear portion, at least one of the panel members is a rear panel member; at least one frame member defines an opening for receiving the rear portion of the server racks to form a hot space between the rear panel member and the combination of the frame member and the rear portion of the server racks; a cooling sub-assembly disposed in thermal communication with the hot space to cool at least one server supported in the server rack and including a chassis receiving at least one heat exchange member for exchanging heat between a refrigerant fluid flowing through the heat exchange member and fluid flowing through the hot space heated by the server.

Abstract: Systems and methods for supplying power (both active and reactive) at a medium voltage from a DCSTATCOM to an IT load without using a transformer are disclosed. The DCSTATCOM includes an energy storage device, a two-stage DC-DC converter, and a multi-level inverter, each of which are electrically coupled to a common negative bus. The DC-DC converter may include two stages in a bidirectional configuration. One stage of the DC-DC converter uses a flying capacitor topology. The voltages across the capacitors of the flying capacitor topology are balanced and switching losses are minimized by fixed duty cycle operation. The DC-DC converter generates a high DC voltage from a low or high voltage energy storage device such as batteries and/or ultra-capacitors. The multi-level, neutral point, diode-clamped inverter converts the high DC voltage into a medium AC voltage using a space vector pulse width modulation (SVPWM) technique.

Abstract: An air flow distribution system for cooling server racks includes at least one server rack partially defining a hot aisle and a cold aisle, a first air foil disposed above the server rack, and a second air foil disposed above the first air foil. The first air foil and the second air foil are configured to receive air from the hot aisle, and to form turbulent wake patterns in the cold aisle partially defined by the server rack. The air flow distribution system may include a convex ceiling member above the second air foil. A corresponding method includes causing air to be directed between a first air foil disposed above a server rack and a second air foil disposed above the first air foil to form turbulent wake patterns in the cold aisle. An electrical enclosure assembly includes a receptacle and a cover member configured as an air foil.

Abstract: The cooling systems and methods of the present disclosure involve modular fluid coolers and chillers configured for optimal power and water use based on environmental conditions and client requirements. The fluid coolers include wet media, a first fluid circuit for distributing fluid across wet media, an air to fluid heat exchanger, and an air to refrigerant heat exchanger. The chillers, which are fluidly coupled to the fluid coolers via pipe cages, include a second fluid circuit in fluid communication with the air to fluid heat exchanger and a refrigerant circuit in thermal communication with the second fluid circuit and in fluid communication with the air to refrigerant heat exchanger. Pipe cages are coupled together to allow for expansion of the cooling system when additional cooling capacity is needed. The fluid coolers and chillers are configured to selectively operate in wet or dry free cooling mode, partial free cooling mode, or mechanical cooling mode.

Abstract: Systems and methods for supplying power at a medium voltage from an uninterruptible power supply (UPS) to a load without using a transformer are disclosed. The UPS includes an energy storage device, a single stage DC-DC converter or a two-stage DC-DC converter, and a multi-level inverter, each of which are electrically coupled to a common negative bus. The DC-DC converter may include two stages in a unidirectional or bidirectional configuration. One stage of the DC-DC converter uses a flying capacitor topology. The voltages across the capacitors of the flying capacitor topology are balanced and switching losses are minimized by fixed duty cycle operation. The DC-DC converter generates a high DC voltage from a low or high voltage energy storage device such as batteries and/or ultra-capacitors. The multi-level, neutral point, diode-clamped inverter converts the high DC voltage into a medium AC voltage using a space vector pulse width modulation (SVPWM) technique.

Abstract: Systems and methods of this disclosure use low voltage energy storage devices to supply power at a medium voltage from an uninterruptible power supply (UPS) to a data center load. The UPS includes a low voltage energy storage device (ultracapacitor/battery), a high frequency (HF) bidirectional DC-DC converter, and a multi-level (ML) inverter. The HF DC-DC converter uses a plurality of HF planar transformers, multiple H-bridge circuits, and gate drivers for driving IGBT devices to generate a medium DC voltage from the ultracapacitor/battery energy storage. The gate drivers are controlled by a zero voltage switching (ZVS) controller, which introduces a phase shift between the voltage on the primary and secondary sides of the transformers.

Abstract: A cooling assembly for cooling server racks includes a server rack enclosure sub-assembly that includes at least one panel member defining a volume for receiving one or more server racks having a front portion and a rear portion, at least one of the panel members is a rear panel member; at least one frame member defines an opening for receiving the rear portion of the server racks to form a hot space between the rear panel member and the combination of the frame member and the rear portion of the server racks; a cooling sub-assembly disposed in thermal communication with the hot space to cool at least one server supported in the server rack and including a chassis receiving at least one heat exchange member for exchanging heat between a refrigerant fluid flowing through the heat exchange member and fluid flowing through the hot space heated by the server.

Abstract: A cooling system includes a heat exchanger having one or more rows of multiple flat tubes, louvered fins disposed between pairs of flat tubes, and special header tube connections to form a counter flow heat exchanger. Heat exchangers having multiple rows may be placed near or close to the server racks and may be in fluid communication with an outdoor heat exchanger having one or more rows. A single-phase fluid is pumped through a fluid circuit or loop, which includes the heat exchangers at the server racks and the outdoor heat exchanger. The single-phase fluid circuit including the heat exchangers at the IT racks may alternatively be in thermal communication with a water circuit that includes an outdoor fluid cooler. The flat tubes can be formed tubes with one or more channels, or extruded tubes with multiple channels. The heat exchangers include header tubes/connections, which facilitate easy fabrication and connection between rows and inlet/outlet, and lower the pressure drop.

Abstract: The cooling systems of the present disclosure include a first refrigerant circuit in thermal communication with a heat load and in fluid communication with a main condenser, a free cooling circuit in fluid communication with the main condenser and a free-cooled water source, a chilled water circuit in fluid communication with the main condenser and an evaporator, and a second refrigerant circuit in fluid communication with the evaporator and a secondary condenser. The free cooling circuit is in thermal communication with the first refrigerant circuit via the main condenser, the chilled water circuit is in thermal communication with the first refrigerant circuit via the main condenser, and the second refrigeration circuit is in thermal communication with the chilled water circuit and the free cooling circuit. The second refrigeration circuit cools a fluid flowing in the chilled water circuit. Methods of operating a cooling system are also disclosed.

Abstract: Systems and methods for supplying power (both active and reactive) at a medium voltage from a DCSTATCOM to an IT load without using a transformer are disclosed. The DCSTATCOM includes an energy storage device, a two-stage DC-DC converter, and a multi-level inverter, each of which are electrically coupled to a common negative bus. The DC-DC converter may include two stages in a bidirectional configuration. One stage of the DC-DC converter uses a flying capacitor topology. The voltages across the capacitors of the flying capacitor topology are balanced and switching losses are minimized by fixed duty cycle operation. The DC-DC converter generates a high DC voltage from a low or high voltage energy storage device such as batteries and/or ultra-capacitors. The multi-level, neutral point, diode-clamped inverter converts the high DC voltage into a medium AC voltage using a space vector pulse width modulation (SVPWM) technique.

Abstract: An air flow distribution system for cooling server racks includes at least one server rack partially defining a hot aisle and a cold aisle, a first air foil disposed above the server rack, and a second air foil disposed above the first air foil. The first air foil and the second air foil are configured to receive air from the hot aisle, and to form turbulent wake patterns in the cold aisle partially defined by the server rack. The air flow distribution system may include a convex ceiling member above the second air foil. A corresponding method includes causing air to be directed between a first air foil disposed above a server rack and a second air foil disposed above the first air foil to form turbulent wake patterns in the cold aisle. An electrical enclosure assembly includes a receptacle and a cover member configured as an air foil.