Converter Output Impedance Estimation Using Beat Frequency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing converter technologies face challenges in accurately estimating the impedance of converter elements, particularly due to the high costs and low practicality of additional circuits required for monitoring changes in element characteristics, which can lead to converter failures.
Innovation Solution
A device and method for estimating impedance of converter output elements by using a data acquisition circuit to measure currents and voltages and an impedance calculation circuit to calculate resistance and reactance components using switching frequencies and beat frequencies from the measurement data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional circuits are used to observe changes in characteristics of converter elements, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent applies multi-functionality by enabling existing converter modules to serve dual purposes: both power conversion and impedance measurement. By using the converter modules themselves to generate excitation signals and measure responses, the system eliminates the need for separate dedicated measurement circuits, thereby improving measurement precision without increasing device complexity
Solution Approach 2:
The patent implements self-service by having the converter modules measure their own impedance characteristics. The converter modules generate test signals, measure their own voltage and current responses, and calculate impedance values internally. This self-measurement approach removes the need for external monitoring circuits while maintaining accurate impedance tracking
2Reliability
If additional circuits are used to observe changes in characteristics of converter elements, then reliability is improved, but manufacturing cost increases
Solution Approach 1:
The patent achieves cost-effective reliability improvement by making existing converter modules multi-functional. The same modules that perform power conversion also perform impedance measurement and health monitoring functions. This eliminates the need for additional costly circuits while maintaining reliable tracking of element characteristics for failure prediction
Solution Approach 2:
The converter modules perform self-diagnosis and self-monitoring of their own health status by measuring impedance changes in their internal elements. This self-service capability provides reliable failure prediction without requiring external monitoring systems, thereby improving reliability while keeping manufacturing costs low
3Measurement precision
If switching frequencies of converter modules are made different, then impedance measurement accuracy is improved, but control complexity increases
Solution Approach 1:
The patent applies periodic action by using the inherent periodic switching of converter modules at different frequencies to generate distinct excitation signals for impedance measurement. By operating modules at different periodic switching frequencies, the system creates measurable voltage and current variations that enable accurate impedance calculation without requiring complex external test signal generation
Solution Approach 2:
The patent implements dynamics by allowing converter modules to operate with variable switching frequencies that can be dynamically adjusted. The control unit dynamically sets different switching frequencies for different modules during measurement periods, enabling accurate impedance differentiation while managing control complexity through coordinated frequency management
Data Source
AI summary
Devices and methods for estimating impedance of an output element are described. According to one embodiment, a device for estimating impedance of an output element comprises a data acquisition circuit to acquire measurement data for currents and voltages of the output element connected to a common output node of a first converter module and a second converter module; and an impedance calculation circuit to calculate impedance of the output element using a component corresponding to a switching frequency of the first converter module and a component corresponding to a beat frequency, which corresponds to a difference between the switching frequency of the first converter module and a switching frequency of the second converter module, from current measurement values and voltage measurement values of the output element.