摘要:
Methods, system and apparatus are provided for controlling third harmonic voltages when operating a multi-phase machine in an overmodulation region. The multi-phase machine can be, for example, a five-phase machine in a vector controlled motor drive system that includes a five-phase PWM controlled inverter module that drives the five-phase machine. Techniques for overmodulating a reference voltage vector are provided. For example, when the reference voltage vector is determined to be within the overmodulation region, an angle of the reference voltage vector can be modified to generate a reference voltage overmodulation control angle, and a magnitude of the reference voltage vector can be modified, based on the reference voltage overmodulation control angle, to generate a modified magnitude of the reference voltage vector. By modifying the reference voltage vector, voltage command signals that control a five-phase inverter module can be optimized to increase output voltages generated by the five-phase inverter module.
摘要:
Embodiments of the present disclosure relate to methods, systems and apparatus for mapping torque to current to generate current commands used to control operation of an electric machine. Based on a DC input voltage, lookup tables (LUTs) are selected. Each of the selected LUTs includes a plurality (B) of first entries that correspond a particular input value of an angular rotation speed of the electric machine, and a set of coefficients are output from each of the selected LUTs that can be applied within a first polynomial function to generate a plurality of first polynomial functions each having a different sets of coefficients. A plurality of particular output values for a first current command are generated via the plurality of first polynomial functions. The particular output values for the first current command can be interpolated to generate a final output value for the first current command.
摘要:
Methods, system and apparatus are provided for overmodulation of a five-phase machine in a vector controlled motor drive system that includes a five-phase PWM controlled inverter module that drives the five-phase machine. Techniques for overmodulating a reference voltage vector are provided to optimize voltage command signals that control a five-phase inverter module to increase output voltages generated by the five-phase inverter module.
摘要:
Methods and systems for operating an electric motor having a plurality of windings with an inverter having a plurality of switches coupled to a voltage source are provided. A first plurality of switching vectors is applied to the plurality of switches. The first plurality of switching vectors includes a first ratio of first magnitude switching vectors to second magnitude switching vectors. A direct current (DC) current associated with the voltage source is monitored during the applying of the first plurality of switching vectors to the plurality of switches. A second ratio of the first magnitude switching vectors to the second magnitude switching vectors is selected based on the monitoring of the DC current associated with the voltage source. A second plurality of switching vectors is applied to the plurality of switches. The second plurality of switching vectors includes the second ratio of the first magnitude switching vectors to the second magnitude switching vectors.
摘要:
Methods, systems and apparatus are provided for controlling operation of and regulating current provided to a five-phase machine when one or more phases has experienced a fault or has failed. In one implementation, the disclosed embodiments can be used to synchronously regulate current in a vector controlled motor drive system that includes a five-phase AC machine, a five-phase inverter module coupled to the five-phase AC machine, and a synchronous current regulator.
摘要:
Systems and methods are disclosed for a dual voltage-source inverter system. The systems and methods selectively couple a first voltage source and a second voltage source to an inverter via a controllable switch.
摘要:
A system is provided for controlling two alternating current (AC) machines via a five-phase PWM inverter module. The system comprises a first control loop, a second control loop, and a current command adjustment module. The current command adjustment module operates in conjunction with the first control loop and the second control loop to continuously adjust current command signals that control the first AC machine and the second AC machine such that they share the input voltage available to them without compromising the target mechanical output power of either machine. This way, even when the phase voltage available to either one of the machines decreases, that machine outputs its target mechanical output power.
摘要:
According to an example embodiment, a method is provided for limiting an operational temperature of a motor. The method includes generating a maximum allowable current I*S(max) for a motor based on a temperature difference between a temperature reference T* of a power inverter module and a semiconductor device temperature T of the power inverter module. The method further includes generating a maximum allowable torque T*e(max) based on the maximum allowable current I*S(max) and a maximum allowable flux Ψ*S(max), and using the maximum allowable torque T*e(max) to limit the torque command T*e in order to suppress the semiconductor device temperature T to below the temperature reference T*.
摘要:
Systems, apparatus, and methods for operating inductors in a Z-source inverter in a continuous current mode are provided. One system includes an AC motor, a Z-source inverter, and a processor. The inverter is configured to provide current and reactive power to the AC motor. The processor is configured to monitor the current and instruct the inverter to provide a greater amount of reactive power to the AC motor if the current is below/equal to a threshold amount. An apparatus includes means for determining if current produced by the inverter is below/equal to a threshold amount, and means for altering voltage commands supplied to the inverter so that an AC motor is induced to draw additional reactive power. One method includes determining if a plurality of inductors are providing a threshold current amount, and inducing a motor to draw more reactive power if the current is below/equal to the threshold amount.
摘要:
A device to regulate current produced by an induction machine responsive to a plurality of phase current signals. The motor produces torque for application on a shaft. A processing and drive circuit responsive to a direct current command signal and a quadrature current command signal produces phase current signals for input to the motor. A command circuit responsive to the phase current signals, an angular position of said shaft, and a voltage input command signal to produce a direct current error signal and a quadrature current error signal. A control circuit responsive to the direct and quadrature current error signals produces the direct voltage signal command and the quadrature signal command. The control circuit has a direct and quadrature proportional gain, integrator and clamp circuits. An algorithm produces limited or clamped voltage modulation index signals to obtain maximum efficiency and maximum torque per ampere in the speed range.