Abstract: For calculating load resistance, a pulse generation module drives a pulse width modulation (PWM) inverter in response to a control voltage. The PWM inverter includes a U phase pole, a V phase pole, and a W phase pole. Each U, V, and W phase pole includes an upper pole device and a lower pole device. The PWM inverter turns off the U phase pole, turns on the W upper pole device, turns off the W lower pole device, and applies the control voltage to the V upper pole device and the V lower pole device. A forward drop correction module corrects the control voltage based on a feedforward compensation voltage determined from a forward voltage drop. A load resistance module calculates a load resistance for a load based on an average control voltage, an average bus voltage, and an average load feedback current.

Abstract: For calculating load resistance, a pulse generation module drives a pulse width modulation (PWM) inverter in response to a control voltage. The PWM inverter includes a U phase pole, a V phase pole, and a W phase pole. Each U, V, and W phase pole includes an upper pole device and a lower pole device. The PWM inverter turns off the U phase pole, turns on the W upper pole device, turns off the W lower pole device, and applies the control voltage to the V upper pole device and the V lower pole device. A forward drop correction module corrects the control voltage based on a feedforward compensation voltage determined from a forward voltage drop. A load resistance module calculates a load resistance for a load based on an average control voltage, an average bus voltage, and an average load feedback current.

Abstract: Power conversion systems, methods and control apparatus to operate a power converter, including a processor computes an angle of an AC output current signal, compute a first voltage error that represents an inverter switch dead time voltage error in a synchronous reference frame according to the angle, computes a compensated voltage command according to the first voltage error and according to a voltage control reference, and controls an inverter according to the compensated voltage command.

Abstract: Methods and apparatus are presented for sampling low side inverter phase currents, in which current sampling is selectively delayed in a given PWM cycle by a non-zero sampling delay time value from a nominal sample time if the middle pulse width value is less than a non-zero first threshold to facilitate adequate signal settling for accurate current measurement, and if a middle total continuous on-time near the end of the given PWM cycle is less than a non-zero second threshold, the middle total continuous on-time is selectively extended by adding a non-zero adjustment offset time value to a middle pulse width value for a next PWM cycle.

Abstract: Methods and apparatus are presented for sampling low side inverter phase currents, in which current sampling is selectively delayed in a given PWM cycle by a non-zero sampling delay time value from a nominal sample time if the middle pulse width value is less than a non-zero first threshold to facilitate adequate signal settling for accurate current measurement, and if a middle total continuous on-time near the end of the given PWM cycle is less than a non-zero second threshold, the middle total continuous on-time is selectively extended by adding a non-zero adjustment offset time value to a middle pulse width value for a next PWM cycle.

Abstract: Methods and apparatus are presented for detecting phase loss and/or excessive ripple in a power converter, in which bandpass filters are used to obtain harmonic voltage amplitudes associated with the power converter DC bus, and phase loss is detected if a ratio of the second harmonic to the sixth harmonic and/or a ratio of the fourth harmonic to the sixth harmonic exceed predetermined threshold values.

Abstract: Methods and apparatus are presented for detecting phase loss and/or excessive ripple in a power converter, in which bandpass filters are used to obtain harmonic voltage amplitudes associated with the power converter DC bus, and phase loss is detected if a ratio of the second harmonic to the sixth harmonic and/or a ratio of the fourth harmonic to the sixth harmonic exceed predetermined threshold values.

Abstract: Control systems, methods and power conversion systems are presented for reducing common mode voltages in AC motor loads driven by inverter PWM control using switching sequences with only active vectors where a first vector of each switching sequence differs by one phase switching state from a last vector of a switching sequence of an adjacent sector, along with enhanced deadtime compensation and reflected wave reduction techniques in providing pulse width modulated switching signals to a switching inverter.

Abstract: Power conversion systems and methods are provided for operating a multi-phase inverter to drive a load while mitigating reflected waves, in which one or more PWM modulating signals are selectively adjusted if at least one of the phase signals or values is transitioning into or out of an over-modulation range outside a pulse width modulation carrier waveform range.

Abstract: Power conversion systems and methods are provided for operating a multi-phase inverter to drive a load while mitigating reflected waves, in which one or more PWM modulating signals are selectively adjusted if at least one of the phase signals or values is transitioning into or out of an over-modulation range outside a pulse width modulation carrier waveform range.

Abstract: Control systems, methods and power conversion systems are presented for reducing common mode voltages in AC motor loads driven by inverter PWM control using switching sequences with only active vectors where a first vector of each switching sequence differs by one phase switching state from a last vector of a switching sequence of an adjacent sector, along with enhanced deadtime compensation and reflected wave reduction techniques in providing pulse width modulated switching signals to a switching inverter.

Abstract: Control systems, methods and fully regenerative power conversion systems are presented for mitigating common mode voltages in AC loads by employing inverter and/or active rectifier PWM control using switching sequences with only active vectors where a first vector of each switching sequence differs by one phase switching state from a last vector of a switching sequence of an adjacent sector.

Abstract: Control systems, methods and power conversion systems are presented for controlling common mode currents in power converters, in which feedback signals used in pulse width modulated inverter switching control are selectively adjusted to ensure minimum differences between the resulting common mode compensated feedback signals according to a common mode dwell time in each pulse width modulation period, with the common mode dwell time being adjusted according to modulation index.

Abstract: Control systems, methods and power conversion systems are presented for controlling common mode voltages in AC motor loads driven by inverter PWM control using switching sequences with only active vectors where a first vector of each switching sequence differs by one phase switching state from a last vector of a switching sequence of an adjacent sector, along with enhanced deadtime compensation and reflected wave reduction techniques in providing pulse width modulated switching signals to a switching inverter.

Abstract: Control systems, methods and fully regenerative power conversion systems are presented for mitigating common mode voltages in AC loads by employing inverter and/or active rectifier PWM control using switching sequences with only active vectors where a first vector of each switching sequence differs by one phase switching state from a last vector of a switching sequence of an adjacent sector.

Abstract: Control systems, methods and power conversion systems are presented for controlling common mode voltages in AC motor loads driven by inverter PWM control using switching sequences with only active vectors where a first vector of each switching sequence differs by one phase switching state from a last vector of a switching sequence of an adjacent sector, along with enhanced deadtime compensation and reflected wave reduction techniques in providing pulse width modulated switching signals to a switching inverter.

Abstract: An apparatus and method for controlling an inverter, the apparatus including an adjustable frequency controller receiving a reference frequency value and generating a command frequency value as a function thereof, an adjustable voltage controller receiving a reference voltage value and generating a command voltage value as a function thereof and independent of the command frequency and a modulator receiving the command frequency value and the command voltage value and generating pulse width modulated (PWM) inverter control signals as a function thereof.

Abstract: A system and method for controlling an inverter of a motor control unit includes a controller having a user interface configured to allow user selection of a waveform increment value or a waveform amplitude threshold. The controller also includes an integrator configured to receive the waveform increment value and generate a signal at least based on the waveform increment value. A logic circuit is configured to monitor the signal and reset the integrator when the signal reaches the waveform amplitude threshold to generate a waveform having a frequency-independent amplitude. A comparator compares the waveform to a modulating signal to trigger gating pulses delivered to an inverter to drive an associated motor.

Abstract: A system and method for controlling an inverter of a motor control unit includes a controller having a user interface configured to allow user selection of a waveform increment value or a waveform amplitude threshold. The controller also includes an integrator configured to receive the waveform increment value and generate a signal at least based on the waveform increment value. A logic circuit is configured to monitor the signal and reset the integrator when the signal reaches the waveform amplitude threshold to generate a waveform having a frequency-independent amplitude. A comparator compares the waveform to a modulating signal to trigger gating pulses delivered to an inverter to drive an associated motor.

Abstract: An apparatus and method for controlling an inverter, an exemplary apparatus comprising an adjustable frequency controller receiving a reference frequency value and generating a command frequency value as a function thereof, an adjustable voltage controller receiving a reference voltage value and generating a command voltage value as a function thereof and independent of the command frequency and a modulator receiving the command frequency value and the command voltage value and generating pulse width modulated (PWM) inverter control signals as a function thereof.