Trimmable Inductor Assembly for Phase Current Balancing
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Solution Overview
Problem
Multi-phase resonant converters face challenges in balancing phase currents due to resonant parameter sensitivity, component tolerances, and temperature variations, leading to potential overheating and inefficiency.
Innovation Solution
A trimmable inductor assembly is introduced, allowing continuous adjustment of resonant inductance to balance phase currents, using a magnetic device with a positioning mechanism to modulate the air gap and thereby the inductance, with current sensing circuitry to detect and correct imbalances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If fixed inductance components are used in multi-phase resonant converters, then manufacturing is simplified, but phase current balance deteriorates due to parameter sensitivity and component tolerances
Solution Approach 1:
The patent applies the dynamics principle by making the inductor adjustable rather than fixed. The trimmable inductor allows continuous adjustment of inductance value to compensate for parameter variations and achieve phase current balance, directly resolving the contradiction between manufacturing simplicity and current balance reliability.
Solution Approach 2:
The patent changes the inductance parameter of the resonant inductor to achieve phase current balance. By allowing the inductance value to be trimmed and adjusted, the system can compensate for component tolerances and parameter variations, thereby maintaining reliable phase current balance while keeping the manufacturing process relatively simple.
2Reliability
If resonant inductance is precisely controlled, then phase current balance is improved, but device complexity increases due to trimmable inductor mechanism
Solution Approach 1:
The trimmable inductor mechanism introduces dynamic adjustability to the inductor assembly. This allows precise control of resonant inductance to achieve phase current balance, accepting increased device complexity as a trade-off for improved reliability and current balance performance.
Solution Approach 2:
The patent employs a mechanical positioning device (such as a screw mechanism) to adjust the air gap and control inductance. This mechanical substitution provides precise control capability while maintaining a relatively simple implementation approach, balancing device complexity with the need for precise inductance control.
3Power
If air gap is reduced to increase inductance, then resonant frequency is adjusted, but manufacturing precision requirements increase
Solution Approach 1:
The patent uses a dynamic air gap adjustment mechanism with a positioning device that allows continuous control of the air gap size. This enables resonant frequency adjustment without requiring extremely high manufacturing precision, as the air gap can be trimmed and adjusted after assembly to achieve the desired inductance value.
Solution Approach 2:
The trimmable inductor design allows preliminary adjustment of the air gap during assembly or calibration. By enabling post-manufacturing adjustment of the air gap, the system reduces the stringency of manufacturing precision requirements while still achieving accurate resonant frequency control and phase current balance.
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 component sensitivity and achieves optimal current balance among phases, enhancing efficiency and preventing overheating by allowing precise adjustment of resonant parameters.
Implementation Method 1
a magnetic device with a positioning mechanism to modulate the air gap and thereby the inductance
Implementation Method 2
A multi-phase resonant converter having circuitry and associated control methods to continuously adjust a resonant inductance
Data Source
AI summary
A trimmable inductor assembly is provided for optimal balancing of phase currents in a multi-phase resonant converter. A magnetic device includes first and second core portions defining an outer edge of the device having a first axis, and further defining a first air gap. A bracket is positioned proximate the outer edge of the device and a magnetic plate is coupled to the bracket, with the magnetic plate and the second core portion defining a second air gap. A positioning device is coupled to the bracket and is responsive to control signals based on a detected phase current imbalance to drive the bracket and the magnetic plate between a first position defining a minimum air gap for the assembly and a second position defining a maximum air gap for the assembly.