Inverter Control via Lookup Table Harmonic Injection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Inefficiencies in controlling inverters in traction vehicles, such as diesel-electric locomotives, lead to reduced overall efficiency due to suboptimal conversion of DC power to AC power for electric motors.

Innovation Solution

A method and system utilizing a look-up table to derive waveform value data for multi-phase reference waveforms, injecting harmonic data to generate control signals that efficiently control IGBT inverters, enhancing power conversion efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional inverter control methods are used, then the system is simple to implement, but the power conversion efficiency is reduced

Engineering Contradiction:

Improvepower conversion efficiencyVSAvoidcontrol system complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent pre-calculates and stores optimal PWM duty cycle values in a lookup table before operation. During runtime, the control system simply retrieves pre-computed values based on modulation index and frequency, avoiding real-time complex calculations and improving power conversion efficiency while maintaining implementation simplicity

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces complex real-time mathematical computation mechanisms with a stored lookup table approach. By substituting computational mechanics with data retrieval, the system achieves faster response and better efficiency without requiring high-performance processors or complex control algorithms

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If precise control signals are generated using look-up tables and harmonic injection, then power conversion efficiency is improved, but the control algorithm complexity increases

Engineering Contradiction:

Improvepower conversion efficiencyVSAvoidcontrol algorithm complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

Harmonic injection parameters and waveform data are pre-calculated and stored in lookup tables during system design. The control algorithm retrieves these pre-prepared harmonic components and combines them with fundamental waveforms, achieving precise control and improved efficiency without requiring complex real-time harmonic calculations

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces lookup tables as an intermediary between the control algorithm and the inverter execution. The lookup tables serve as a bridge that translates control parameters into precise PWM signals with embedded harmonic injection, simplifying the control algorithm while maintaining high precision and efficiency

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS8405250B2Electronic device control system and method

Publication Date: 2013.03.26 WESTINGHOUSE AIR BRAKE TECH CORP

AI summary

There is provided a system and method for controlling an electronic device. An exemplary method comprises employing a look-up table to derive waveform value data for a multi-phase reference waveform. The exemplary method also comprises employing the look-up table to derive waveform value data corresponding to harmonic data for the multi-phase reference waveform. Harmonic data is injected into the multi-phase reference waveform to produce a harmonic reference waveform. The exemplary method additionally comprises generating a plurality of control signals from the harmonic reference waveform.