Abstract: A chiller system includes a compressor configured to circulate a refrigerant between an evaporator and a condenser in a closed refrigerant loop and a synchronous motor configured to drive the compressor. The motor includes a stator winding and a rotor. The chiller system includes a controller configured to estimate a flux linkage of the rotor and generate a control signal for the motor based on the estimated flux linkage. Estimating the flux linkage includes applying a voltage of the stator winding to a transfer function having an error correction variable, using a first value of the error correction variable in the transfer function to obtain convergence of the flux linkage over an initial motor starting interval, and using a second value of the error correction variable after the initial motor starting interval to reduce an error in estimating the flux linkage.

Abstract: A variable speed drive includes a converter connected to an AC power source, a DC link connected to the converter, and an inverter connected to the DC link. The inverter converts DC voltage into an output AC power having a variable voltage and frequency. The inverter includes at least one power electronics module and associated control circuitry; a heat sink in thermal communication with the power electronics module and in fluid communication with a manifold. The manifold includes a tubular member having at least one vertical member portion and at least one horizontal member portion in fluid communication. A plurality of ports conduct cooling fluid into and out of the manifold. A bracket attaches the manifold to a structural frame. Brackets are provided for attachment of power electronics modules to the manifold.

Abstract: A converter module for a variable speed drive having a semiconductor device for precharge is described. The precharge circuit includes switching modules, one switching module with a first semiconductor switch connected in parallel or series with a second semiconductor switch. The second semiconductor switch is switched on and off during the precharge operation in order to limit the inrush current into the DC Link. After the precharge operation, the second semiconductor switch is turned on all the time and acts like a diode. The second semiconductor device may have a lower maximum current rating than the main semi-conductor devices. The lower current rated semiconductor device experience the same short circuit current as the higher current rated semiconductor device. The lower current rated semiconductor device can be supplied with a larger gate to emitter voltage than the higher current rated semiconductor device to equalize current between semiconductor devices.

Abstract: A grounding system for a semiconductor module of a variable speed drive includes a first conductive layer, a second conductive layer; a substrate disposed between the first conductive layer and the second conductive layer; and a base attached to the second conductive layer, the base being connected to earth ground via a grounding harness. The first conductive layer is in electrical contact with the semiconductor module and the substrate, and electrically insulated from the second conductive layer by the substrate. The second conductive layer is in electrical contact with the substrate and disposed between the substrate and the base in electrical communication with an earth ground. The first conductive layer, the substrate and the second conductive layer form a capacitance path between the semiconductor module and the base as well as electrical conductors and the base for reduction circulating currents within the semiconductor module.

Abstract: A cooling system for a motor powering a compressor in a vapor compression system includes a housing and a cavity within the housing. A first fluid circuit has a first connection to receive a refrigerant into the cavity, and a second connection to deliver refrigerant from the cavity to a heat exchanger for a heat transfer relationship with a heat-generating component.

Abstract: A cooling member for a variable speed drive is disclosed. The cooling member includes including at least two channels, each channel including at least one inlet and at least one outlet, a first passageway configured to provide fluid to the at least two channels through the at least one inlet of each channel, a second passageway configured to receive fluid from the at least one outlet of each channel the at least two channels, and a connector to connect the cooling member to a second cooling member.

Abstract: A method is disclosed for controlling a synchronous motor by determining a rotor position of the synchronous motor based on estimating a flux linkage. The method includes applying a voltage of a stator winding of the motor to a transfer function. The transfer function includes an S-domain integration operation and an error correction variable. An output of the transfer function is processed to compensate for the error correction variable introduced in the transfer function. An estimated flux linkage is generated and an angle of the rotor position is computed based on the flux linkage. The computed rotor position is input to a controller for controlling a position or speed of the motor.

Abstract: A converter module for a variable speed drive having a semiconductor device for precharge is described. The precharge circuit includes switching modules, one switching module with a first semiconductor switch connected in parallel or series with a second semiconductor switch. The second semiconductor switch is switched on and off during the precharge operation in order to limit the inrush current into the DC Link. After the precharge operation, the second semiconductor switch is turned on all the time and acts like a diode. The second semiconductor device may have a lower maximum current rating than the main semi-conductor devices. The lower current rated semiconductor device experience the same short circuit current as the higher current rated semiconductor device. The lower current rated semiconductor device can be supplied with a larger gate to emitter voltage than the higher current rated semiconductor device to equalize current between semiconductor devices.

Abstract: A chiller system is provided with a compressor, a condenser, and an evaporator connected in a closed refrigerant loop. A motor is connected to the compressor to power the compressor. A variable speed drive is connected to the motor. The variable speed drive is arranged to receive an input AC power at a fixed input AC voltage and a fixed input frequency and provide an output power at a variable voltage and variable frequency to the motor. The variable voltage has a maximum voltage greater in magnitude than the fixed input AC voltage and the variable frequency has a maximum frequency greater than the fixed input frequency. The variable speed drive includes a converter connected to an AC power source providing the input AC voltage, the converter is arranged to convert the input AC voltage to a DC voltage. A DC link is connected to the converter. The DC link is arranged to filter and store the DC voltage from the converter. An inverter is connected to the DC link.

Abstract: A drive system for a compressor of a chiller system includes a variable speed drive. The variable speed drive receives an input AC power at a fixed input AC voltage and a fixed input frequency, and provides an output AC power at a variable voltage and variable frequency. The variable speed drive includes a converter connected to an AC power source. The converter is arranged to convert the input AC voltage to a DC voltage. A DC link is connected to the converter and configured to filter and store the DC voltage from the converter. An inverter is connected to the DC link. A motor is connectable to the compressor for powering the compressor. A controller is arranged to control switching in the converter and the inverter. The controller is arranged to apply randomized pulse width modulation to vary the switching frequency of transistors in the converter and the inverter at each switching cycle. The motor may be a permanent magnet synchronous motor.

Abstract: A drive system for a compressor of a chiller system includes a variable speed drive. The variable speed drive is arranged to receive an input AC power at a fixed AC input voltage and fixed input frequency and provide an output AC power at a variable voltage and variable frequency. The variable speed drive includes a converter connected to an AC power source providing the input AC voltage. The converter is arranged to convert the input AC voltage to a DC voltage. A DC link is connected to the converter. The DC link is arranged to filter and store the DC voltage from the converter. A first inverter and a second inverter are each connected to the DC link. A motor includes stator windings connected between the first inverter and the second inverter to power the motor by the output AC power from the first inverter and the second inverter. The motor is connectable to a compressor of the chiller system to power the compressor. The motor may be a permanent magnet synchronous motor.

Abstract: A hybrid motor for powering a compressor of a chiller system includes a first rotor portion and a first stator portion configured as a permanent magnet motor and a second rotor portion and a second stator portion configured as a reluctance motor. The second rotor portion includes a reluctance-type rotor, and the second stator portion includes electromagnetic windings capable of inducing a rotary magnetic field. The first rotor portion and the second rotor portion are attached to a common drive shaft. The reluctance motor is arranged to generate start-up torque and initiate rotation of the drive shaft until the drive shaft achieves a predetermined rotational speed. The permanent magnet motor is arranged to power the drive shaft between the predetermined rotational speed and a maximum rotational speed.

Abstract: A drive system for a compressor of a chiller system includes a variable speed drive. The variable speed drive is arranged to receive an input AC voltage at a fixed AC input voltage and provide an output AC power at a variable voltage and variable frequency. The variable speed drive includes a converter connected to an AC power source providing the input AC voltage. The converter is arranged to convert the input AC voltage to a DC voltage. A DC link is connected to the converter. The DC link filters and stores the DC voltage from the converter. An inverter is connected to the DC link. A motor connectable to the compressor for powering the compressor. An active filter connected in parallel with the motor. The active filter is arranged to generate high frequency currents having a magnitude and opposite polarity, with respect to the output AC power of the variable speed drive. The high frequency currents generated by active filter substantially cancel out high frequency currents flowing into the motor.

Abstract: Systems and methods for improved VSDs are provided. One embodiment relates to an apparatus for common mode and differential mode filtering for motor or compressor bearing protection when operating with VSDs, including conducted EMI/RFI input power mains mitigation. Another embodiment relates to a method to extend the synchronous operation of an Active Converter to the AC mains voltage during complete line dropout. Another embodiment relates to an Active Converter-based Variable Speed Drive system with Improved Full Speed Efficiency.

Abstract: A cooling member for a variable speed drive. The variable speed drive has a component that generates heat during operation of the drive and a base. The base has a surface that receives the component, a channel formed in the surface of the base and a passageway formed in the base and receiving fluid therethrough. Fluid flowing through the passageway provides cooling to the component and the base is manufactured from an injection molding process.

Abstract: Systems and methods for operating a variable speed drive to receive an input AC power at a fixed AC input voltage and frequency and provide an output AC power at a variable voltage and variable frequency. The variable speed drive includes a converter stage to convert the input AC voltage to a boosted DC voltage, a DC link connected to the converter stage to filter and store the boosted DC voltage from the converter stage; and an inverter stage to convert the boosted DC voltage into AC power with variable voltage and the variable frequency. An integral bypass contactor is connected in parallel with the VSD between the AC power source and the AC output power. The integral bypass contactor is arranged to bypass the VSD when the VSD output frequency and voltage are approximately equal with the AC input voltage and frequency.

Abstract: Systems and methods for improved VSDs are provided. One embodiment relates to an apparatus for common mode and differential mode filtering for motor or compressor bearing protection when operating with VSDs, including conducted EMI/RFI input power mains mitigation. Another embodiment relates to a method to extend the synchronous operation of an Active Converter to the AC mains voltage during complete line dropout. Another embodiment relates to an Active Converter-based Variable Speed Drive system with Improved Full Speed Efficiency.

Abstract: Systems and methods for improved Variable Speed Drives are provided. One embodiment relates to apparatus for common mode and differential mode filtering for motor or compressor bearing protection when operating with Variable Speed Drives, including conducted EMI/RFI input power mains mitigation. Another embodiment relates to a method to extend the synchronous operation of an Active Converter to the AC mains voltage during complete line dropout. Another embodiment relates to an Active Converter-based Variable Speed Drive system with Improved Full Speed Efficiency. Another embodiment relates to a liquid- or refrigerant-cooled inductor. The liquid- or refrigerant-cooled inductor may be used in any application where liquid or refrigerant cooling is available and a reduction in size and weight of a magnetic component is desired.

Abstract: A grounding system for a semiconductor module of a variable speed drive includes a first conductive layer, a second conductive layer; a substrate disposed between the first conductive layer and the second conductive layer; and a base attached to the second conductive layer, the base being connected to earth ground via a grounding harness. The first conductive layer is in electrical contact with the semiconductor module and the substrate, and electrically insulated from the second conductive layer by the substrate. The second conductive layer is in electrical contact with the substrate and disposed between the substrate and the base in electrical communication with an earth ground. The first conductive layer, the substrate and the second conductive layer form a capacitance path between the semiconductor module and the base as well as electrical conductors and the base for reduction circulating currents within the semiconductor module.

Abstract: A plastic liquid cooled variable speed drive or inductor provided. The cooler provides lightweight, space conservative, corrosive free cooling to the components as well as provides a mounting area for modules. A cooler can be mounted to the core of an inductor to absorb heat generated by the core losses.