INTRODUCTION

The information provided in this section is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

The present disclosure relates to inverters for motors of vehicles and more particularly to current source inverters and systems and methods for controlling current source inverters.

Some types of vehicles include only an internal combustion engine that generates propulsion torque. Electric vehicles may not include an internal combustion engine and may rely on one or more electric motors for propulsion.

Hybrid vehicles include both an internal combustion engine and one or more electric motors. Some types of hybrid vehicles utilize the electric motor and the internal combustion engine in an effort to achieve greater fuel efficiency than if only the internal combustion engine was used. Some types of hybrid vehicles utilize the electric motor and the internal combustion engine to achieve greater torque output than the internal combustion could achieve by itself.

Some example types of hybrid vehicles include parallel hybrid vehicles, series hybrid vehicles, and other types of hybrid vehicles. In a parallel hybrid vehicle, the electric motor works in parallel with the engine to combine power and range advantages of the engine with efficiency and regenerative braking advantages of electric motors. In a series hybrid vehicle, the engine drives a generator to produce electricity for the electric motor, and the electric motor drives a transmission. This allows the electric motor to assume some of the power responsibilities of the engine, which may permit the use of a smaller and possibly more efficient engine.

SUMMARY

In a feature, a motor control system includes: a d-q target module configured to, based on a target torque of an electric motor, determine a first target d-axis current for the electric motor and a first target q-axis current for the electric motor; an offset module configured to, based on a capacitor current through capacitors connected across phases of the electric motor, determine a d-axis current offset and a q-axis current offset; an adder module configured to determine a second target d-axis current based on a sum of the first target d-axis current and the d-axis current offset and to determine a second target q-axis current based on a sum of the first target q-axis current and the q-axis current offset; and a driver module configured to, based on the second target d-axis current and the second target q-axis current, switch switches of a current source inverter (CSI) module configured to apply power to the phases of the electric motor.

In further features, a capacitor current module is configured to determine the capacitor current based on at least one of (a) a current input to the CSI module, (b) a speed of the electric motor, and (c) a modulation index of the CSI module.

In further features, the capacitor current is measured using a current sensor.

In further features, the d-q target module is configured to determine the first target d-axis current and the first target q-axis current further based on a speed of the electric motor.

In further features, the driver module is configured to switch the switches of the CSI module further based on a d-axis current of the electric motor and a q-axis current of the electric motor.

In further features, the driver module is configured to switch the switches of the CSI module based on (a) a difference between a d-axis current of the electric motor and the second target d-axis current and (b) a difference between a q-axis current of the electric motor and the second target q-axis current.

In further features, a second driver module is configured to, based on the first target d-axis current and the first target q-axis current, switch switches of a voltage to current converter module configured to output current to the CSI module based on voltage from a battery.

In further features: a CSI target module is configured to, based on the first d-axis current and the first q-axis current, determine a target current output from a voltage to current converter module to the CSI module; and a second driver module is configured to, based on the target current, switch switches of the voltage to current converter module.

In further features, the second driver module is configured to switch the switches of the voltage to current converter module further based on a current output from the voltage to current converter module to the CSI module.

In further features, the second driver module is configured to switch the switches of the voltage to current converter module based on a difference between (a) a current output from the voltage to current converter module to the CSI module and (b) the target current output from the voltage to current converter module to the CSI module.

In further features, a capacitor is connected in parallel with the battery, and a voltage to current converter module is configured to convert voltage from the capacitor into current and to output the current to the CSI module.

In a feature, a motor control method includes: based on a target torque of an electric motor, determining a first target d-axis current for the electric motor and a first target q-axis current for the electric motor; based on a capacitor current through capacitors connected across phases of the electric motor, determining a d-axis current offset and a q-axis current offset; determining a second target d-axis current based on a sum of the first target d-axis current and the d-axis current offset; determining a second target q-axis current based on a sum of the first target q-axis current and the q-axis current offset; and based on the second target d-axis current and the second target q-axis current, switching switches of a current source inverter (CSI) module configured to apply power to the phases of the electric motor.

In further features, the motor control method further includes determining the capacitor current based on at least one of (a) a current input to the CSI module, (b) a speed of the electric motor, and (c) a modulation index of the CSI module.

In further features, the motor control method further includes measuring the capacitor current using a current sensor.

In further features, determining the first target d-axis current and the first target q-axis current includes determining the first target d-axis current and the first target q-axis current further based on a speed of the electric motor.

In further features, switching the switches of the CSI module includes switching the switches of the CSI module further based on a d-axis current of the electric motor and a q-axis current of the electric motor.

In further features, switching the switches of the CSI module includes switching the switches of the CSI module based on (a) a difference between a d-axis current of the electric motor and the second target d-axis current and (b) a difference between a q-axis current of the electric motor and the second target q-axis current.

In further features, the motor control method further includes, based on the first target d-axis current and the first target q-axis current, switching switches of a voltage to current converter module configured to output current to the CSI module based on voltage from a battery.

In further features, the motor control method further includes: based on the first d-axis current and the first q-axis current, determining a target current output from a voltage to current converter module to the CSI module; and based on the target current, switching switches of the voltage to current converter module.

In further features, switching the switches of the voltage to current converter module includes switching the switches of the voltage to current converter module further based on a current output from the voltage to current converter module to the CSI module.

Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.

