摘要:
Methods and systems are provided for aligning a resolver in an electric motor system. The method includes commanding a d-axis current command and a speed command, operating an electric motor without a load in response to the d-axis current command and the speed command, determining a rotor speed in response to the speed command, and determining an offset of the resolver based on the speed command and the rotor speed when the rotor speed has substantially stabilized.
摘要:
A hybrid powertrain system includes an engine, an electric machine, a power electronics device including a plurality of electric circuit layers, and a cooling system. A method for managing thermal energy in the power electronics device includes monitoring a plurality of temperature sensors in the power electronics device, monitoring electric power into and out of the power electronics device, predicting temperatures for the plurality of electric circuit layers, and controlling the hybrid powertrain system based upon the predicted temperatures for the plurality of electric circuit layers.
摘要:
Methods and systems for operating an inverter having a plurality of high switches and a plurality of low switches coupled to an electric motor are provided. An event indicative of deceleration of the electric motor is detected. The inverter is alternated between a first mode of operation and a second mode of operation during the deceleration of the electric motor. In the first mode of operation, each of the plurality of high switches is activated and each of the plurality of low switches is deactivated or each of the plurality of low switches is activated and each of the plurality of high switches is deactivated. In the second mode of operation, each of the plurality of high switches is deactivated and each of the plurality of low switches is deactivated.
摘要:
In an embodiment of a method, the method includes measuring currents and voltages that are coupled to a motor that includes an internal permanent magnet and determining a reactive power in response to the measured currents and voltages. The method further includes estimating a first flux orthogonal to an axis of the internal permanent motor and estimating a second flux aligned with the axis of the internal permanent motor. Additionally, the method includes estimating a torque in response to the measured currents and the first and second fluxes.
摘要:
Methods and apparatus are provided for compensating for a deviation in voltage output of a phase leg inverter when dead-time periods are inserted to prevent shoot-through failures. The method includes determining a pulse width for an input signal to the inverter such that the inverter voltage output is a desired amount. The pulse width is based on the non-inverted or inverted pulse sequences of two carrier signals and the polarity of current through the inverter. An amount of pulse width is added to the input signal when the current is positive, and an amount of pulse width is subtracted from the input signal when the current is negative. An additional amount of pulse width is added to or subtracted from the input signal depending on whether the carrier signal sequence changes from a non-inverted signal to an inverted signal or changes from an inverted signal to a non-inverted signal, respectively.
摘要:
Temperature of an electric drive is regulated to prevent undesirable thermal effects. Temperature conditions of the electric drive system are monitored and torque of the electric drive system is limited based on the temperature conditions.
摘要:
Methods and systems for operating a motor coupled to an electrical bus in a vehicle are provided. Selected resonant frequencies of the electrical bus are determined. The selected resonant frequencies include a low resonant frequency and a high resonant frequency. Power is provided to the motor through at least one switch operating at a switching frequency. The switching frequency is controlled as a function of a rate of operation of the motor. The function is characterized by one of a first substantially linear portion having a first slope when the switching frequency is less than or equal to a selected switching frequency and a second substantially linear portion having a second slope if the switching frequency is greater than the selected frequency, the selected switching frequency being greater than the low resonant frequency and a substantially linear portion having a y-intercept being greater than the low resonant frequency.
摘要:
Methods and apparatus are provided for reducing voltage distortion effects at low speed operation in electric drives. The method comprises receiving a first signal having a duty cycle with a range between minimum and maximum achievable duty cycles, producing a second duty cycle based on the minimum achievable duty cycle if the duty cycle is within a distortion range and less than a first clipping value, producing a second duty cycle based on the closer of minimum and maximum pulse widths if the duty cycle is within the distortion range and between the first and a second clipping value, producing a second duty cycle based on the maximum achievable duty cycle if the duty cycle is within the distortion range and greater than the second clipping value, and transmitting a second signal to the voltage source inverter having the second duty cycle.
摘要:
Apparatus, systems, and methods are provided for reducing voltage source inverter losses. One apparatus includes a sensor couplable to the motor and configured to sense an operating frequency of the motor and an amount of torque produced by the motor. The apparatus also includes a controller coupled to the sensor, the controller configured to determine a zero vector modulation (ZVM) based on the sensed frequency and torque. A system includes means for sensing a threshold output frequency of the motor and means for sensing a threshold torque of the motor. The system also includes means for determining a ZVM for the inverter based on the sensed threshold frequency and threshold torque. One method includes sensing that a motor is operating below a threshold frequency and is producing torque above a threshold torque amount. The method also includes determining a ZVM for the inverter based on the sensed frequency and torque.
摘要:
Method and system are provided for controlling an alternating current (AC) motor via an inverter. The method includes selecting a pulse sequencing method based on a modulation index of the inverter, and providing a voltage to the AC motor based on the pulse sequencing method. The system includes an inverter having a modulation index (Mi) and a controller coupled to the inverter. The controller selects a pulse sequencing method based on Mi and produces a signal based on the pulse sequencing method. The inverter includes a switch network producing a voltage in response to the signal, and the voltage drives the AC motor.