Abstract: Vehicles and related systems and monitoring methods are provided for detecting a loss of isolation on one side of a power converter. One method involves monitoring a normalized voltage input to a power conversion module coupled to the electric motor, in response to the normalized voltage exceeding a diagnostic activation threshold, determining a first number of instances of a range between successive extremas of the normalized voltage exceeding a loss of isolation range threshold over a diagnostic window of time, and automatically initiating a remedial action when the first number is greater than a loss of isolation detection threshold.

Abstract: In an embodiment, a method is provided for controlling a plurality of converters that are coupled to a plurality of cells of a rechargeable energy storage system (RESS) and configured to supply electric current to other systems that require the electric current, the method including obtaining, via one or more sensors, cell data as to the plurality of cells, the cell data including a state-of-charge for each of the plurality of cells; obtaining other system data as to the other systems, including an amount of electric current required by the other systems; and controlling the plurality of converters, in accordance with instructions provided by a processor, based on both: the cell data, including the state-of-charge for each of the plurality of cells; and the other system data, including the amount of electric current by the other systems.

Abstract: A dual inverter open winding machine for a vehicle. The machine may include an electric motor, a first energy source, a first inverter, a second energy source, and a second inverter. The first inverter may include a plurality of first switches independently operable between an opened position and a closed position to selectively connect and disconnect a first direct current (DC) port and a first alternating current (AC) port with one or more of the first energy source, the first inverter, and the motor. The second inverter may include a plurality of second switches independently operable between an opened position and a closed position to selectively connect and disconnect a second DC port and a second AC port with one or more of the second energy source, the second inverter, and the motor.

Abstract: Apparatus and techniques for analyzing a capacitance value in an electric motor inverter are disclosed. A processor is coupled to a DC-AC inverter, which includes a capacitor across its terminals and is powered by a battery. The processor performs resistor switching to enable singular, periodic measurement of the capacitance. The measured value is compared with a nominal or beginning of life (BOL) value. An alert may be sent if the capacitance has degraded beyond a threshold. In other aspects, the DC torque ripple envelop is used to measure capacitance. The outcome is compared with the other tests to assess consistency. An inconsistent outcome may identify potential resistor degradation.

Abstract: A method, apparatus, and control system are described for operating a multiphase motor drive system including a rotary electric machine and an inverter. An AC choke filter is arranged proximal to output leads from the inverter. A reference temperature associated with the AC choke filter is determined along with an operating point of the electric machine. Operation of the inverter is controlled based upon a temperature of the AC choke filter, the reference temperature, and an operating point of the electric machine. This includes modifying a switching frequency and a PWM type in a manner that reduces the AC choke filter temperature by reducing the occurrence of switching events to protect the AC choke filter based on temperature feedback.

Abstract: A dual inverter open winding machine for a vehicle. The machine may include an electric motor, a first energy source, a first inverter, a second energy source, and a second inverter. The first inverter may include a plurality of first switches independently operable between an opened position and a closed position to selectively connect and disconnect a first direct current (DC) port and a first alternating current (AC) port with one or more of the first energy source, the first inverter, and the motor. The second inverter may include a plurality of second switches independently operable between an opened position and a closed position to selectively connect and disconnect a second DC port and a second AC port with one or more of the second energy source, the second inverter, and the motor.

Abstract: A system includes an inverter configured to output multiphase alternating current (AC) currents to an electric motor, the multiphase AC currents including a first phase current and a second phase current, the inverter including a set of switches for each phase current. The system also includes a switching controller operably connected to each set of switches, the switching controller configured to control a gate driver connected to a switch of the set of switches, the switching controller configured to determine a time difference between a first switching event of a first phase and a second switching event of a second phase during a switching cycle, and control a switching speed of the switch based on the time difference.

Abstract: A cooling system for a drivetrain of an electric vehicle includes a coolant circuit directing a flow of coolant through a first inverter and a second inverter of the drivetrain, and an adjustable flow valve positioned along the coolant circuit to selectably alter proportions of the flow of coolant directed through each of the first inverter and the second inverter. A method of operating a cooling system for a first inverter and a second inverter of a vehicle drivetrain includes commanding a speed and torque of each of the first and second inverter, and estimating losses and temperature of each of the first inverter and the second inverter as a result of the commanded speed and torque. A valve position of an adjustable flow valve operably connected to the first inverter and the second inverter is selected, and a change of the valve position is commanded.

Abstract: An electric motor circuit includes a motor controller having a plurality of gate drivers and an inverter configured to receive direct current (DC) power from a source and output alternating current (AC) power to an electric motor. The inverter includes a plurality of transistor elements. Each transistor element includes multiple transistors arranged on a transistor board. Multiple temperature sensors are configured to monitor a plurality of temperatures on each transistor element. The motor controller is configured to alter a pulse width modulation (PWM) control of a first subset of transistors on a first transistor element in response to a first subset of temperature sensors detecting a temperature exceeding a threshold temperature and a second subset of temperature sensors not detecting a temperature exceeding the threshold.

Abstract: A control system for a rotary electric machine includes an inverter including a plurality of power switches, a heat exchanger, first temperature sensors arranged to monitor the power switches, a second temperature sensor arranged to monitor the heat exchanger, and a controller. An expected power loss is determined based upon electric current, switching functions, and electrical characteristics of the power switches. A plurality of power capacity terms are determined based upon the expected power loss in the inverter, the temperatures of the power switches, and the temperature of the heat exchanger. The inverter is controlled based upon the aforementioned power capacities.

Abstract: The concepts described herein provide a method, apparatus, and system for controlling an inverter by modifying duty cycles of the PWM control signals in a manner that achieves a minimum duration between consecutive switching events in the inverter, which serves to reduce common mode current in the bearing(s) of an attached rotary electric machine. To minimize the effect of additional current and voltage ripple into the system, the minimum switching duration is defined in relation to a modulation index and geometric location near the sector boundaries of the respective inverter voltage space vector diagram.

Abstract: Tandem charging for electric vehicles (EVs) electrically interconnected with each other. The tandem charging may include determining a plurality of EVs requesting to be charged with electrical power available from a charging station, determining charging parameters for the EVs, scheduling charging of the EVs according to the charging parameters, and/or authorizing a pecuniary charge to billing accounts of the EVs in recompense for the charging.

Abstract: A system includes an electronic device including a circuit having a semiconductor switch, and a controller configured to control a gate driver connected to the semiconductor switch via a protection circuit. The controller is configured to set a protection parameter including a voltage threshold representing a selected value of a voltage across the semiconductor switch, the protection parameter configured to cause the semiconductor switch to be deactivated in response to an overcurrent condition, the protection parameter selected based on a mathematical model of the semiconductor switch, the mathematical model representing a physical property of at least one of the electronic device and the semiconductor switch.

Abstract: A control system for a rotary electric machine includes an inverter including a plurality of power switches, a heat exchanger, first temperature sensors arranged to monitor the power switches, a second temperature sensor arranged to monitor the heat exchanger, and a controller. An expected power loss is determined based upon electric current, switching functions, and electrical characteristics of the power switches. A plurality of power capacity terms are determined based upon the expected power loss in the inverter, the temperatures of the power switches, and the temperature of the heat exchanger. The inverter is controlled based upon the aforementioned power capacities.

Abstract: A method and apparatus for operating an electric drive unit having an inverter operatively coupled to a polyphase alternating current (AC) motor includes receiving a torque command corresponding to a torque to be produced by the AC motor; receiving a heat level request corresponding to a heat to be generated within the electric drive unit; determining a final current command that is responsive to the torque command and to the heat level request, wherein the current command includes operating in a flux-intensifying region relative to a Maximum Torque Per Ampere (MTPA) curve; and commanding operation of the inverter responsive to the final current command.

Abstract: A method, apparatus, and control system are described for operating a multiphase motor drive system including a rotary electric machine and an inverter. An AC choke filter is arranged proximal to output leads from the inverter. A reference temperature associated with the AC choke filter is determined along with an operating point of the electric machine. Operation of the inverter is controlled based upon a temperature of the AC choke filter, the reference temperature, and an operating point of the electric machine. This includes modifying a switching frequency and a PWM type in a manner that reduces the AC choke filter temperature by reducing the occurrence of switching events to protect the AC choke filter based on temperature feedback.

Abstract: Presented are motor control systems, vehicles, and methods for generating motor heat while holding an offset motor torque during stationary vehicle operation. A method of operating an AC motor includes a resident or remote vehicle controller receiving a mode request to operate a vehicle in a stationary mode, and a temperature request including the AC motor generating motor heat during the stationary operating mode. The controller determines an offset motor torque to generate the motor heat and hold the AC motor's output member at a select position when operating the vehicle in the stationary mode. Using a DQ transform model of the AC motor, the controller selects multiple dq current trajectories located in respective dq operating quadrants of the DQ transform model based on the offset motor torque. The controller then commands a power inverter to transmit electrical current to the AC motor based on the select dq current trajectories.

Abstract: Apparatus and techniques for analyzing a capacitance value in an electric motor inverter are disclosed. A processor is coupled to a DC-AC inverter, which includes a capacitor across its terminals and is powered by a battery. The processor performs resistor switching to enable singular, periodic measurement of the capacitance. The measured value is compared with a nominal or beginning of life (BOL) value. An alert may be sent if the capacitance has degraded beyond a threshold. In other aspects, the DC torque ripple envelop is used to measure capacitance. The outcome is compared with the other tests to assess consistency. An inconsistent outcome may identify potential resistor degradation.

Abstract: The concepts described herein provide a method, apparatus, and system for controlling an inverter by modifying duty cycles of the PWM control signals in a manner that achieves a minimum duration between consecutive switching events in the inverter, which serves to reduce common mode current in the bearing(s) of an attached rotary electric machine. To minimize the effect of additional current and voltage ripple into the system, the minimum switching duration is defined in relation to a modulation index and geometric location near the sector boundaries of the respective inverter voltage space vector diagram.

Abstract: A control system for a rotary electric machine includes an inverter including a plurality of power switches, a heat exchanger, first temperature sensors arranged to monitor the power switches, a second temperature sensor arranged to monitor the heat exchanger, and a controller. An expected power loss is determined based upon electric current, switching functions, and electrical characteristics of the power switches. A plurality of power capacity terms are determined based upon the expected power loss in the inverter, the temperatures of the power switches, and the temperature of the heat exchanger. The inverter is controlled based upon the aforementioned power capacities.