Resonant Power Converter Frequency Tracking at Load-Independent Points
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Solution Overview
Problem
Non-contact power transfer systems face efficiency issues due to changes in positional relationships between power transmission and receiving coils affecting resonance frequency, requiring complex control mechanisms and increased calculation costs, especially with load fluctuations.
Innovation Solution
A resonance-type power converter circuit with a detector circuit, calculation controller, and signal generator that detects output information to determine a load-independent operating frequency, using a maximum point search method to control the switching element and maintain optimal operating frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the positional relationship between power transmission coil and power receiving coil changes, then the inductance changes and resonance frequency changes, but switching frequency and resonance frequency do not match, adversely affecting efficiency
Solution Approach 1:
The patent implements dynamic frequency adjustment by continuously monitoring output characteristics (voltage or current) and adjusting the switching frequency in real-time to track the resonance frequency. This dynamic adaptation ensures the switching frequency matches the resonance frequency even when inductance changes due to positional variations, thereby maintaining high power conversion efficiency without requiring complex control mechanisms.
2Reliability
If a mechanism for controlling drive circuit of switching element is added to match switching frequency with resonance frequency, then frequency matching is achieved, but device complexity and volume increase
Solution Approach 1:
The patent employs a self-service control mechanism where the system automatically adjusts its own operating parameters. By detecting output characteristics and using this information to control the drive circuit of the switching element, the system self-regulates frequency matching without requiring external control mechanisms or additional complexity. This self-service approach maintains frequency matching accuracy while minimizing device complexity.
3Ease of operation
If output characteristics are controlled to satisfy charging profile, then charging requirements are met, but circuit design and control become complicated
Solution Approach 1:
The patent implements a feedback control mechanism where output characteristics (voltage or current) are continuously detected and fed back to control the drive circuit of the switching element. This feedback loop automatically adjusts the system operation to satisfy charging profile requirements without requiring complicated circuit design or control logic. The feedback mechanism simplifies the overall system by using the output information itself for control purposes.
4Adaptability or versatility
If phase control is implemented to achieve load independency in class E resonance-type inverter, then load independency is achieved, but calculation cost of control controller becomes large
Solution Approach 1:
The patent achieves load independency through a self-service mechanism that automatically adapts to load changes by detecting output characteristics and adjusting operating parameters accordingly. This approach eliminates the need for complex phase control calculations and large calculation controllers, thereby achieving load independency with minimal calculation cost and maintaining system simplicity.
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 reduces calculation costs and maintains efficiency by achieving load-independent operation and zero-volt switching, addressing the inefficiencies and complexity in existing systems.
Implementation Method 1
a resonance circuit 1, a detector circuit 2, a calculation controller 3, and a signal generator 4. The resonance circuit 1 includes a first LC resonance circuit and a switching element Q1
Implementation Method 2
a power receiving coil mounted on the AGV is electromagnetically coupled to a power transmitting coil of a charging station to perform non-contact charging
Data Source
AI summary
A resonance-type power converter circuit includes: a resonance circuit including a first LC resonance circuit and a switching element, and outputting an output voltage or current to a load; a detector circuit detecting output information; an calculation controller searching for a maximum point in a characteristic of the output information at an operating frequency based on the detected output information, and determining an operating frequency corresponding to the searched maximum point; and a signal generator generating a drive control signal having the determined operating frequency, and controlling the frequency based on the drive control signal. The resonance circuit has a characteristic of output information at the operating frequency having a load independent point not depending on the load and corresponding to the maximum point and feeds back a drive control signal including the output information to the switching element and drives it at the load independent point by frequency control.