Inverter Control for Eco-Friendly Vehicles

Solution Overview

Problem

Conventional inverter control methods for eco-friendly vehicles suffer from fixed switching and sampling frequencies, leading to inefficiencies in switching loss, electromagnetic performance, noise-vibration-harshness (NVH) performance, and control stability, as they do not adapt to varying motor conditions.

Innovation Solution

An inverter control system that dynamically adjusts switching frequency and sampling frequency based on current motor speed, using a controller to generate PWM signals and control the ON/OFF driving of switching elements, allowing for variable switching frequencies and mode transitions between single-sampling and double-sampling modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the inverter's switching frequency is set high and fixed (e.g., to 8 kHz), then NVH performance becomes better (PWM current ripple is reduced), but electromagnetic performance is deteriorated and switching loss increases

Engineering Contradiction:

ImproveNVH performanceVSAvoidswitching loss

Core Design Contradiction:

Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The patent implements dynamic switching frequency adjustment where the controller varies the switching frequency based on motor operating conditions (speed, torque, temperature). The switching frequency is not fixed but adapts in real-time, transitioning between different frequency ranges to optimize both NVH performance and switching loss under different operating scenarios.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the switching frequency parameter dynamically according to motor operating conditions. The controller adjusts the switching frequency within a predetermined range (e.g., 4-8 kHz or wider ranges) based on feedback from sensors monitoring motor speed, torque, and temperature, thereby optimizing the trade-off between NVH performance and switching loss.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If the inverter's switching frequency is set high and fixed (e.g., to 8 kHz), then NVH performance becomes better (PWM current ripple is reduced), but electromagnetic performance is deteriorated

Engineering Contradiction:

ImproveNVH performanceVSAvoidelectromagnetic performance

Core Design Contradiction:

Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent implements dynamic switching frequency adjustment where the controller varies the switching frequency based on motor operating conditions (speed, torque, temperature). The switching frequency is not fixed but adapts in real-time, transitioning between different frequency ranges to optimize both NVH performance and switching loss under different operating scenarios.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the switching frequency parameter dynamically according to motor operating conditions. The controller adjusts the switching frequency within a predetermined range (e.g., 4-8 kHz or wider ranges) based on feedback from sensors monitoring motor speed, torque, and temperature, thereby optimizing the trade-off between NVH performance and switching loss.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If one fixed switching frequency and one fixed sampling frequency are used over the entire operation area, then control simplicity is maintained, but overall performance deteriorates in terms of switching loss, electromagnetic performance, and NVH performance

Engineering Contradiction:

Improvecontrol simplicityVSAvoidswitching loss

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The patent implements dynamic switching frequency adjustment where the controller varies the switching frequency based on motor operating conditions (speed, torque, temperature). The switching frequency is not fixed but adapts in real-time, transitioning between different frequency ranges to optimize both NVH performance and switching loss under different operating scenarios.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the switching frequency parameter dynamically according to motor operating conditions. The controller adjusts the switching frequency within a predetermined range (e.g., 4-8 kHz or wider ranges) based on feedback from sensors monitoring motor speed, torque, and temperature, thereby optimizing the trade-off between NVH performance and switching loss.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9172316B2Inverter control method and system for eco-friendly vehicle

Publication Date: 2015.10.27 HYUNDAI MOTOR CO LTD

AI summary

Provided is an inverter control system and method for an eco-friendly vehicle, by which overall improvements can be obtained in terms of switching loss, electromagnetic performance, noise-vibration-harshness (NVH) performance, control stability, and so forth, when compared to a conventional case in which one fixed switching frequency and one fixed sampling frequency are used over the entire operation area. To this end, the inverter control method for an eco-friendly vehicle which generates a pulse width modulation (PWM) signal according to a switching frequency and a sampling frequency and controls ON/OFF driving of a switching element, in which a controller changes and sets the switching frequency according to a current motor speed, changes and sets a sampling frequency according to the switching frequency, and controls on/off driving of a switching element according to the switching frequency corresponding to the motor speed and the sampling frequency.