Abstract:
A first rectifier diode is electrically connected between a first input terminal where an alternating current (AC) power is received and a first output terminal where a direct current (DC) power is output. A second rectifier diode is electrically connected between the first input terminal and a second output terminal. The first and second rectifier diodes rectify first and second portions of the AC power into the DC power, respectively. When switching of a plurality of power factor correction (PFC) switches is enabled, the plurality of PFC switches increases a voltage of the DC power to greater than a peak voltage of the AC power. An inductor is electrically connected between a second input terminal and two of the plurality of PFC switches. When the switching is disabled, first and second bypass diodes provide a current path past the plurality of PFC switches and the inductor.
Abstract:
A power factor correction (PFC) system includes an adjustment module, a compensation module, and a duty cycle control module. The adjustment module generates N time advances based on N predetermined time advances and (N-1) time advance adjustments, wherein N is an integer greater than zero. The compensation module generates N compensated versions of an input alternating current (AC) line signal by predicting ahead of the input AC line signal using a gradient of a sinusoidal reference signal and the N time advances, respectively, wherein the sinusoidal reference signal is synchronized with the input AC line signal in phase and frequency. The duty cycle control module generates PFC duty cycles based on the N compensated versions of the input AC line signal.
Abstract:
A system includes a compressor having a shell housing a compression mechanism driven by an electric motor in an on state and not driven by the electric motor in an off state. The system also includes a variable frequency drive that drives the electric motor in the on state by varying a frequency of a voltage delivered to the electric motor and that supplies electric current to a stator of the electric motor in the off state to heat the compressor.
Abstract:
A power factor correction (PFC) system includes a period determination module, a frequency generation module, an angle generation module, a signal generation module, and an angle correction module. The period determination module determines a period of an input alternating current (AC) line signal based on a time between rising edges of the input AC line signal. The frequency generation module generates a frequency based on the period. The angle generation module generates an angle based on the frequency. The signal generation module generates a sinusoidal reference signal based on the frequency and an adjusted angle. The angle correction module generates the adjusted angle based on the angle and based on a comparison of a falling edge of the sinusoidal reference signal, the period, and a rising edge of the input AC line signal.
Abstract:
A first rectifier diode is electrically connected between a first input terminal where an alternating current (AC) power is received and a first output terminal where a direct current (DC) power is output. A second rectifier diode is electrically connected between the first input terminal and a second output terminal. The first and second rectifier diodes rectify first and second portions of the AC power into the DC power, respectively. When switching of a plurality of power factor correction (PFC) switches is enabled, the plurality of PFC switches increases a voltage of the DC power to greater than a peak voltage of the AC power. An inductor is electrically connected between a second input terminal and two of the plurality of PFC switches. When the switching is disabled, first and second bypass diodes provide a current path past the plurality of PFC switches and the inductor.
Abstract:
A motor control system includes a control module, a switching module, and a filtering module. The control module determines output voltages for operating a motor based on a torque demand. The switching module generates switching signals for an inverter that drives the motor. The switching module generates the switching signals based on the output voltages. The switching module generates an out-of-volts (OOV) signal according to a comparison based on the output voltages, a maximum duty cycle, and a voltage of a direct current (DC) bus that provides power to the inverter. The filtering module generates an OOV amount by filtering the OOV signal. The control module selectively limits the torque demand based on the OOV amount.
Abstract:
A compressor may include a shell, a compression mechanism, a drive shaft, and first and second bearing housing assemblies. The compression mechanism may be supported within the shell and the drive shaft may have a first end drivingly engaged with the compression mechanism. The second bearing housing assembly may be located within and fixed to the shell. The second bearing housing may include a radially extending base portion defining an aperture rotatably supporting a second end of the drive shaft therein. The second bearing housing may additionally include a wall portion extending axially from the base portion and having a first region coupled to the shell at a first location, a second region coupled to the shell at a second location and a third region extending from the first region to the second region.
Abstract:
A compressor includes orbiting and non-orbiting scroll members meshingly engaged to form a series of compression pockets, including first pockets when the orbiting scroll member is in a first position. A first porting in the non-orbiting scroll member communicates with the first pockets during a portion of a compression cycle. The first pockets include a set of radially outermost pockets located radially inward relative to the first porting and isolated from communication with the first porting during the compression cycle. The first porting is aligned with a spiral wrap of the orbiting scroll member at a location radially outward from and directly adjacent the first pockets when the orbiting scroll member is in the first position. Additional porting communicates with each of the compression pockets located radially outward relative to the first pockets when the orbiting scroll member is in the first position.
Abstract:
A compressor may include a housing and first and second scroll members supported within the housing, each having an end plate with a spiral wrap extending therefrom and meshingly engaged with the other to form a series of compression pockets operating at an intermediate fluid pressure between a suction pressure and a discharge pressure. A first passage in communication with one of the compression pockets extends from a first side of the first end plate to a second side of the first end plate generally opposite the first side. A modulation plate overlies the second side of the first scroll member for radial displacement between first and second positions. The modulation plate isolates the first passage from communication with a suction pressure region of the compressor when in the first position and provides communication between the first passage and the suction pressure region when in the second position.
Abstract:
A compressor monitoring system includes current and voltage monitors, current and voltage averaging modules, a control module, and a switch. The current monitor measures a current drawn by a motor of a compressor. The current averaging module generates first and second average current values based on the current measured by the current monitor. The voltage monitor measures a utility power voltage. The voltage averaging module generates first and second average voltage values based on the voltage measured by the voltage monitor. The control module selectively generates a fault signal when a first ratio is greater than a first predetermined threshold and a second ratio is less than a second predetermined threshold. The first ratio is based on the first and second average current values. The second ratio is based on the first and second average voltage values. The switch deactivates the motor when the fault signal is generated.