Fuel Injector Heating Control via Phase-Shifted Excitation Currents
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing devices for heating fuel injectors in internal combustion engines face challenges with electromagnetic compatibility issues due to high current undulations, which require large capacitors for filtering, increasing device size and cost, especially in limited spaces like motor vehicles.
Innovation Solution
A method and device that phase-shift electric excitation currents to maintain a constant sum of absolute amplitudes, eliminating current undulations and eliminating the need for EMC filters, thereby reducing device size and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If H bridges are phase shifted to reduce current undulations, then electromagnetic interference is reduced, but the control complexity increases
Solution Approach 1:
The patent applies periodic action by phase-shifting the H bridges in a systematic periodic manner. Each H bridge is activated in sequence with specific phase shifts (e.g., 0°, 90°, 180°, 270°) to ensure that the sum of absolute amplitudes remains constant throughout the cycle, thereby reducing current undulations and electromagnetic interference while maintaining manageable control complexity through regular patterns
Solution Approach 2:
The patent changes the temporal parameter (phase angle) of each H bridge's operation. By adjusting the phase shift parameter of each H bridge relative to others, the system transforms the current delivery pattern to maintain constant amplitude sum, thus reducing electromagnetic interference without requiring fundamental changes to the H bridge architecture
2Reliability
If EMC filters with large capacitors are used to absorb current undulations, then electromagnetic compatibility is improved, but device size increases
Solution Approach 1:
The patent extracts and eliminates the need for large EMC filtering capacitors by fundamentally changing the H bridge operation pattern. Instead of adding filtering components to handle current undulations, the phase-shifting method prevents undulations from occurring in the first place, thereby removing the requirement for large capacitors and reducing device size
Solution Approach 2:
The patent converts the potentially harmful current undulations into a beneficial constant amplitude sum through phase-shifting. By intentionally introducing phase shifts that cause H bridges to operate at different times, the system transforms what would be harmful simultaneous switching into a beneficial staggered operation that maintains constant total amplitude
3Power
If H bridges deliver current simultaneously, then heating power is maximized, but current amplitude variations become severe
Solution Approach 1:
The patent uses periodic phase-shifting patterns to distribute H bridge activation throughout the cycle. By systematically rotating which H bridges are active at different phase angles, the system maintains continuous power delivery while smoothing out amplitude variations, achieving both heating effectiveness and current stability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces electromagnetic interference and eliminates the need for large capacitors, resulting in a compact, reliable, and cost-effective control device for heating fuel injectors.
Implementation Method 1
a plurality of electromagnetic induction means (9), each of said electromagnetic induction means being connected to an injector (5) of the plurality of fuel injectors and being configured, when an electric excitation current passes through said electromagnetic induction means, to heat said injector (5) by induction
Implementation Method 2
the electric excitation current signals are phase shifted, such that the sum of absolute values of the amplitudes of said signals is constant
Data Source
AI summary
A method, and associated device, for controlling a module for heating a plurality of fuel injectors of an engine of a vehicle, the heating module including a plurality of electromagnetic induction elements each connected to an injector of the plurality of fuel injectors and being configured, when an electric excitation current passes through the electromagnetic induction elements, to heat the injector by induction, the method including a step of generating an electric supply current and a step of generating, from the electric supply current, a plurality of electric excitation currents phase shifted relative to one another and materialized by electric excitation current signals, each of the electric excitation currents intended to supply one of the electromagnetic induction elements. The method being notable in that the electric excitation current signals are phase shifted such that the sum of the absolute values of the amplitudes of the signals is constant.