Abstract: Cooling systems and methods use first and second evaporators and first and second liquid refrigerant distribution units to increase the efficiency of the cooling systems and methods. The first evaporator is in thermal communication with an air intake flow to a heat load, and the first liquid refrigerant distribution unit is in thermal communication with the first evaporator. The second evaporator is disposed in series with the first evaporator in the air intake flow and is in thermal communication with the air intake flow, and the second liquid refrigerant distribution unit is in thermal communication with the second evaporator. A trim compression cycle of the second liquid refrigerant distribution unit is configured to further cool the air intake flow through the second evaporator when the temperature of the first fluid flowing out of a main compressor of the second liquid refrigerant distribution unit exceeds a predetermined threshold temperature.

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: Modular dual power sources and corresponding systems include a common hybrid energy storage system, a high frequency DC-DC converter coupled between the common hybrid energy storage system, and an ultra-capacitor module for starting up a generator, and a two-level inverter coupled to the common hybrid energy storage system to provide power in case of an interruption in power supplied by a utility supply. The hybrid energy storage system includes an ultra-capacitor module and a battery module. A fast charger is coupled to the hybrid energy storage system to quickly charge the ultra-capacitor module and the battery module, which, in turn, charge the ultra-capacitor module for starting up a generator via a high frequency DC-DC converter. High frequency transformers are used to magnetically isolate electrical noise of the generator and UPS functions and operate independently. The modular dual power sources can be connected in parallel to provide large MW output power.

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: 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: An efficient, modular, direct current (DC) uninterruptible power supply (UPS) for at least one server of a data center is disclosed. The single-conversion DC UPS includes an AC-DC converter, an energy storage device electrically coupled to the output of the AC-DC converter, and a single conversion server supply DC-DC converter electrically coupled to the AC-DC converter and the energy storage device, which may be a low-voltage lithium-ion battery or combined with an ultra capacitor. The DC UPS may be incorporated into a UPS system for a data center including a plurality of server rack assemblies and a plurality of cooling distribution units (CDUs). The UPS system includes an electric generator, an AC UPS electrically coupled between the electric generator and the plurality of CDUs, and a plurality of DC UPSs coupled between the electric generator and the plurality of server rack assemblies.

Abstract: A modular server rack cooling structure for cooling at least one server in at least one server rack of a data center assembly includes at least a first supporting member and at least a first heat exchanger. The first heat exchanger is coupled to the first supporting member, which is configured to position the first heat exchanger in heat transfer relationship with the at least one server. The first heat exchanger is not attached to the at least one server rack. The modular server rack cooling structure is also applied to a system that includes at least a first rack and at least a second rack disposed opposite from one another to form a hot aisle or a cold aisle. A method is disclosed for installing additional heat exchangers on the support structure of a modular server rack cooling structure to meet increased cooling capacity requirements without requiring additional space.

Abstract: Systems and methods relating to a plural in-series pumped liquid refrigerant trim evaporator cycle are described. The cooling systems include a first evaporator coil in thermal communication with an air intake flow to a heat load, and a first liquid refrigerant distribution unit in thermal communication with the first evaporator coil. The cooling systems further include a second evaporator coil disposed in series with the first evaporator coil in the air intake flow and in thermal communication with the air intake flow, and a second liquid refrigerant distribution unit in thermal communication with the second evaporator coil. A trim compression cycle of the second liquid refrigerant distribution unit is configured to further cool the air intake flow through the second evaporator coil when the temperature of the first fluid flowing out of the main compressor of the second liquid refrigerant distribution unit exceeds a predetermined threshold temperature.

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: A space-saving, high-density modular data pod and a method of cooling a plurality of computer racks are disclosed. The modular data pod includes an enclosure including wall members contiguously joined to one another along at least one edge of each wall member in the shape of a polygon and a data pod covering member. Computer racks arranged within the enclosure form a first volume between the inner surface of the wall members and first sides of the computer racks. A second volume is formed of second sides of the computer racks. A computer rack covering member encloses the second volume and the data pod covering member form a third volume coupling the first volume to the second volume. An air circulator continuously circulates air through the first, second, and third volumes. The method includes circulating air between the first and second volumes via the third volume and the computer racks.

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 space-saving, high-density modular data center and an energy-efficient cooling system for a modular data center are disclosed. The modular data center includes a first cooling circuit including a primary cooling device and a plurality of modular data pods. Each modular data pod includes a plurality of servers, a heat exchange member coupled to the first cooling circuit and a second cooling circuit coupled to the heat exchange member and configured to cool the plurality of servers, the second cooling circuit including a secondary cooling device configured to cool fluid flowing through the second cooling circuit. Each modular data pod also includes an auxiliary enclosure containing at least a portion of a distributed mechanical cooling system, which is configured to trim the cooling performed by a central free-cooling system.

Abstract: Systems and methods for cooling an inverter of a variable frequency drive that drives a compressor in a cooling system for electronic equipment are disclosed. The system includes a first fluid circuit that cools electronic equipment using a first fluid flowing therethrough and a second fluid circuit that free cools a second fluid flowing therethrough. The second fluid circuit cools the first fluid using the free-cooled second fluid. The system further includes a third fluid circuit that mechanically cools the second fluid using a third fluid flowing therethrough as a function of the wet bulb temperature of atmospheric air. The third fluid circuit includes at least one compressor compresses the third fluid and is driven by a motor coupled to the variable frequency drive. At least a portion of the first fluid flowing through the third fluid circuit is diverted to cool the inverter of the variable frequency drive.

Abstract: An efficient, modular, direct current (DC) uninterruptible power supply (UPS) for at least one server of a data center is disclosed. The single-conversion DC UPS includes an AC-DC converter, an energy storage device electrically coupled to the output of the AC-DC converter, and a single conversion server supply DC-DC converter electrically coupled to the AC-DC converter and the energy storage device, which may be a low-voltage lithium-ion battery or combined with an ultra capacitor. The DC UPS may be incorporated into a UPS system for a data center including a plurality of server rack assemblies and a plurality of cooling distribution units (CDUs). The UPS system includes an electric generator, an AC UPS electrically coupled between the electric generator and the plurality of CDUs, and a plurality of DC UPSs coupled between the electric generator and the plurality of server rack assemblies.

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 for cooling an inverter of a variable frequency drive that drives a compressor in a cooling system for electronic equipment are disclosed. The system includes a first fluid circuit that cools electronic equipment using a first fluid flowing therethrough and a second fluid circuit that free cools a second fluid flowing therethrough. The second fluid circuit cools the first fluid using the free-cooled second fluid. The system further includes a third fluid circuit that mechanically cools the second fluid using a third fluid flowing therethrough as a function of the wet bulb temperature of atmospheric air. The third fluid circuit includes at least one compressor compresses the third fluid and is driven by a motor coupled to the variable frequency drive. At least a portion of the first fluid flowing through the third fluid circuit is diverted to cool the inverter of the variable frequency drive.

Abstract: A power distribution system for data center systems (and corresponding method) feeds DC power directly to a first AC-DC power supply of a computer system in the data center system and feeds AC power to a second AC-DC power supply of the computer system to efficiently and reliably provide an uninterruptible supply of power to the computer system. The power distribution system includes an energy storage unit for supplying the DC power, a charger for charging the energy storage unit, and an inverter through which the energy storage unit provides energy to an electrical substation of an electrical grid. The charger is configured to receive energy from a renewable energy source and the electrical substation. The inverter may also be configured to receive renewable energy from the renewable energy source and supply that energy to the electrical substation. An uninterruptible power supply may be coupled between the electrical substation and the AC power feed.