Abstract: An HVAC system includes an unloading device, a centrifugal compressor, a gas foil bearing, a VFD and a controller. The controller is programmed to start the centrifugal compressor from a stopped condition by operating the unloading device to remove a load from the centrifugal compressor, accelerating the motor to a first speed above a liftoff speed of the gas foil bearing and below an operating speed of the centrifugal compressor, running the motor for a period of time, operating the unloading device to apply the load to the centrifugal compressor, and accelerating the motor to the operating speed.

Abstract: A system includes a dynamic compressor to compress a working fluid and a controller. The controller is connected to the dynamic compressor and includes a processor and a memory. The memory stores a map of predetermined operating points of the dynamic compressor, each predetermined operating point including a mass flow of the compressor at that predetermined operating point. The memory stores instructions that program the processor to operate the dynamic compressor to compress the working fluid and determine a current operating point of the compressor. The instructions program the processor to calculate the mass flow for the current operating point from the map of the plurality of predetermined operating points. The instructions further program the processor to continue to operate the dynamic compressor to compress the working fluid based at least in part on the calculated mass flow for the current operating point.

Abstract: A method for determining a mass flow of a dynamic compressor that does not include a mass flow sensor while the compressor is operating to compress a working fluid includes determining, by a processor, a current operating point of the compressor. If the current operating point is the same as one in a map of a plurality of predetermined operating points stored in a memory, the mass flow of that predetermined operating point is retrieved as the mass flow of the current operating point. Otherwise, the processor calculates the mass flow at the current operating point from the mass flows of a subset of the predetermined operating points nearest the current operating point. The dynamic compressor continues to operate to compress the working fluid based at least in part on the calculated mass flow rate for the current operating point.

Abstract: An HVAC system includes an unloading device, a centrifugal compressor, a gas foil bearing, a VFD and a controller. The controller is programmed to start the centrifugal compressor from a stopped condition by operating the unloading device to remove a load from the centrifugal compressor, accelerating the motor to a first speed above a liftoff speed of the gas foil bearing and below an operating speed of the centrifugal compressor, running the motor for a period of time, operating the unloading device to apply the load to the centrifugal compressor, and accelerating the motor to the operating speed.

Abstract: A system includes a compressor, an indoor fan, a thermostat, an indoor fan controller, and a compressor controller. The thermostat provides first and second signals based on indoor loading. The fan controller operates the fan in low speed mode and the compressor controller operates the compressor in low capacity mode when only the first signal is asserted. The compressor controller automatically switches the compressor to high capacity mode if only the first signal remains asserted past the low capacity mode runtime. The fan controller operates the fan in high speed mode when the second signal is asserted while the first signal is still asserted. The compressor controller continues to operate the compressor in high capacity mode and the fan controller operates the fan in low speed mode after the second signal is de-asserted, until the first signal is de-asserted, at which point the fan and compressor are turned off.

Abstract: A system includes a compressor, an indoor fan, a thermostat, an indoor fan controller, and a compressor controller. The thermostat provides first and second signals based on indoor loading. The fan controller operates the fan in low speed mode and the compressor controller operates the compressor in low capacity mode when only the first signal is asserted. The compressor controller automatically switches the compressor to high capacity mode if only the first signal remains asserted past the low capacity mode runtime. The fan controller operates the fan in high speed mode when the second signal is asserted while the first signal is still asserted. The compressor controller continues to operate the compressor in high capacity mode and the fan controller operates the fan in low speed mode after the second signal is de-asserted, until the first signal is de-asserted, at which point the fan and compressor are turned off.

Abstract: A system includes a compressor, an indoor fan, a thermostat, an indoor fan controller, and a compressor controller. The thermostat provides first and second signals based on indoor loading. The fan controller operates the fan in low speed mode and the compressor controller operates the compressor in low capacity mode when only the first signal is asserted. The compressor controller automatically switches the compressor to high capacity mode if only the first signal remains asserted past the low capacity mode runtime. The fan controller operates the fan in high speed mode when the second signal is asserted while the first signal is still asserted. The compressor controller continues to operate the compressor in high capacity mode and the fan controller operates the fan in low speed mode after the second signal is de-asserted, until the first signal is de-asserted, at which point the fan and compressor are turned off.

Abstract: A system includes a compressor, an indoor fan, a thermostat, an indoor fan controller, and a compressor controller. The thermostat provides first and second signals based on indoor loading. The fan controller operates the fan in low speed mode and the compressor controller operates the compressor in low capacity mode when only the first signal is asserted. The compressor controller automatically switches the compressor to high capacity mode if only the first signal remains asserted past the low capacity mode runtime. The fan controller operates the fan in high speed mode when the second signal is asserted while the first signal is still asserted. The compressor controller continues to operate the compressor in high capacity mode and the fan controller operates the fan in low speed mode after the second signal is de-asserted, until the first signal is de-asserted, at which point the fan and compressor are turned off.

Abstract: A system and method for controlling an automatic operation of a power door of a vehicle is presented. An actuation of an interior switch by a user is detected and, upon detecting the actuation of the interior switch, whether at least one door of the vehicle is locked is determined. When the at least one door of the vehicle is locked, whether a vehicle security is set is determined. When the at least one door of the vehicle is locked and the vehicle security is set, the automatic operation of the power door is prohibited. When the at least one door of the vehicle is not locked or the vehicle security is not set, the automatic operation of the power door is permitted.

Abstract: A system and method for preventing thermal damage to an electric motor in a vehicle includes arrangements for monitoring the motor and detecting a cycle of the motor. If the cycle occurred within a predetermined increment time, a cycle count is incremented. If no cycle occurs for a predetermined decrement time, the cycle count is decremented if the cycle count is greater than zero. If the cycle count is at least equal to a cycle limit, power operation of the motor is deactivated for at least the decrement time. The method may include continuously calculating energy consumed by the motor and, if the energy consumed exceeds one or more allowable energy thresholds, setting the cycle count equal to the cycle limit. The method may further include detecting a failure condition and setting the cycle count equal to the cycle limit when the failure condition is detected.

Abstract: A system and method for preventing damage to a controller of an electric motor in a vehicle from back electromotive force, the vehicle having a battery, includes monitoring, in a circuit path, a voltage and a rotational speed generated by back-driving the motor. If power is supplied to the controller by the battery, the method includes comparing the voltage to an upper voltage threshold, comparing the rotational speed to an upper rotational speed threshold, and, if the voltage exceeds the upper voltage threshold or the rotational speed exceeds the upper rotational speed threshold, clamping the circuit path to the battery to charge the battery with the voltage. The method is performed by an electronic controller that may detect the voltage and rotational speed via controller ports, sensor transmissions, and the like.

Abstract: A system and method for controlling an automatic operation of a power door of a vehicle is presented. An actuation of an interior switch by a user is detected and, upon detecting the actuation of the interior switch, whether at least one door of the vehicle is locked is determined. When the at least one door of the vehicle is locked, whether a vehicle security is set is determined. When the at least one door of the vehicle is locked and the vehicle security is set, the automatic operation of the power door is prohibited. When the at least one door of the vehicle is not locked or the vehicle security is not set, the automatic operation of the power door is permitted.

Abstract: A system and method for controlling an operation of a power door of a vehicle are presented. An activation of a user interface device associated with the power door is detected. A cue is provided using a notification device after detecting the activation of the user interface device. In one implementation, the notification device includes an audible alarm. When the user interface device is activated for greater than a predetermined time period, the power door is caused to be in a power mode of operation, and the notification device is used to indicate a current operational mode of the power door. In one implementation, when the user interface device is deactivated within the predetermined time period, the power door is caused to be in a manual mode of operation.

Abstract: A system and method for preventing thermal damage to an electric motor in a vehicle includes arrangements for monitoring the motor and detecting a cycle of the motor. If the cycle occurred within a predetermined increment time, a cycle count is incremented. If no cycle occurs for a predetermined decrement time, the cycle count is decremented if the cycle count is greater than zero. If the cycle count is at least equal to a cycle limit, power operation of the motor is deactivated for at least the decrement time. The method may include continuously calculating energy consumed by the motor and, if the energy consumed exceeds one or more allowable energy thresholds, setting the cycle count equal to the cycle limit. The method may further include detecting a failure condition and setting the cycle count equal to the cycle limit when the failure condition is detected.

Abstract: A system and method for preventing damage to a controller of an electric motor in a vehicle from back electromotive force, the vehicle having a battery, includes monitoring, in a circuit path, a voltage and a rotational speed generated by back-driving the motor. If power is supplied to the controller by the battery, the method includes comparing the voltage to an upper voltage threshold, comparing the rotational speed to an upper rotational speed threshold, and, if the voltage exceeds the upper voltage threshold or the rotational speed exceeds the upper rotational speed threshold, clamping the circuit path to the battery to charge the battery with the voltage. The method is performed by an electronic controller that may detect the voltage and rotational speed via controller ports, sensor transmissions, and the like.

Abstract: A system and method for controlling an operation of a power door of a vehicle are presented. An activation of a user interface device associated with the power door is detected. A cue is provided using a notification device after detecting the activation of the user interface device. In one implementation, the notification device includes an audible alarm. When the user interface device is activated for greater than a predetermined time period, the power door is caused to be in a power mode of operation, and the notification device is used to indicate a current operational mode of the power door. In one implementation, when the user interface device is deactivated within the predetermined time period, the power door is caused to be in a manual mode of operation.