An electric drive system includes a rechargeable energy storage unit, a power inverter, an electric motor and a controller having a processor and tangible, non-transitory memory on which instructions are recorded. A transfer of electrical power between the rechargeable energy storage unit and the electric motor is governed by a pulse width modulation (PWM) switching frequency. The controller is configured to determine a current switching frequency based in part on a PWM type, a PWM switching frequency style and an inverter direct current voltage. A PWM scalar is determined based in part on the current switching frequency and a maximum value of a control reference frequency. The controller is configured to transmit a command signal to regulate the transfer of electrical power based in part on the PWM scalar, the PWM switching frequency being proportional to a product of the PWM scalar and the control reference frequency.

An electric motor may comprise a rotor and a stator. One or more first cables connected to a first power converter circuit of are wrapped adjacent to at least some stator teeth of a stator core to form at least a first portion of one or more coil windings. One or more second cables connected to a second power converter circuit of the plurality of power converter circuit also may be wrapped adjacent to at least some of the stator teeth to form at least a second portion of the one or more coil windings.

An electric motor may comprise a rotor and a stator. One or more first cables connected to a first power converter circuit of are wrapped adjacent to at least some stator teeth of a stator core to form at least a first portion of one or more coil windings. One or more second cables connected to a second power converter circuit of the plurality of power converter circuit also may be wrapped adjacent to at least some of the stator teeth to form at least a second portion of the one or more coil windings.

A system and method for controlling a DC midpoint terminal voltage of a three level inverter is provided. The method includes receiving an input power signal at a three level motor control system that includes a three level inverter, the three level inverter powering an electric motor, determining, in the three level motor control system, a speed value of the electric motor, and adjusting a zero-sequence inverter output voltage to adjust a midpoint voltage at the DC midpoint based on the determined speed value.

A system and method for controlling a DC midpoint terminal voltage of a three level inverter is provided. The method includes receiving an input power signal at a three level motor control system that includes a three level inverter, the three level inverter powering an electric motor, determining, in the three level motor control system, a speed value of the electric motor, and adjusting a zero-sequence inverter output voltage to adjust a midpoint voltage at the DC midpoint based on the determined speed value.

In a power conversion apparatus, first to xth converters are connected in parallel to each other. A control unit outputs, based on command information related to an output of the power conversion apparatus, control information. A pulse generator selects, based on the control information, a number n of converters from the first to xth converters, n being an integer more than or equal to 2 and smaller than x. The number n is defined as a multiply-driven number n. The pulse generator generates, based on the control information, at least one multiple drive-pulse train that comprises n drive pulses for multiply driving the n selected converters. A variable determiner changes the multiply-driven number n.

A system is provided for driving multiple motors. The system includes multiple cascaded H-bridge (CHB) power inverters, a DC bus, and multiple neutral point converter/inverters. Each of the multiple CHB power inverters is connected to a respective motor at one or more AC terminals of the CHB power inverter. Each of the multiple CHB power inverters includes one or more DC terminals configured to receive DC power. Each of the multiple neutral point converter/inverters is connected to a respective CHB power inverter at one or more neutral terminals of the respective CHB power inverter and connected to the DC bus.

A method for operating switching elements of a multilevel energy converter using at least three electric potentials and to which a multiphase electrical machine is connected. Switching elements of the multilevel energy converter are operated in a predefined clock mode by corresponding switching signals. The switching signals for the switching elements are each assigned to one of the phases and are determined in accordance with each desired voltage signal, in order to apply a phase voltage to each phase of the multiphase electrical machine. The switching signals are determined additionally in accordance with a predefined overlaying voltage signal such that an overlaying voltage dependent on the overlaying voltage signal is overlaid onto each phase voltage.

A method for operating switching elements of a multilevel energy converter using at least three electric potentials and to which a multiphase electrical machine is connected. Switching elements of the multilevel energy converter are operated in a predefined clock mode by corresponding switching signals. The switching signals for the switching elements are each assigned to one of the phases and are determined in accordance with each desired voltage signal, in order to apply a phase voltage to each phase of the multiphase electrical machine. The switching signals are determined additionally in accordance with a predefined overlaying voltage signal such that an overlaying voltage dependent on the overlaying voltage signal is overlaid onto each phase voltage.

A motor module includes a motor and a rotation angle detector including a rotation angle calculator that calculates a rotation angle based on a voltage and an electric current of the motor, a first signal generator that generates a first signal based on a ripple component included in the electric current, an operation part that corrects the rotation angle based on the first signal and the rotation angle, and a rotation information calculator that calculates information on rotation of the motor based on an output from the operation part. The operation part outputs, to the rotation angle calculator, a command to correct the rotation angle when the first signal is generated for the first time while the rotation angle is within a predetermined angle range, and ignores the first signal that is generated for the second or subsequent time while the rotation angle is within the predetermined angle range.