Matrix Converter Carrier Frequency Control for Lower Switching Heat
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power conversion devices generate significant heat in switching elements, which affects efficiency and reliability.
Innovation Solution
A power conversion device with a matrix converter circuit and a control system that adjusts the frequency of a carrier wave based on the nearness level between the primary and secondary side frequencies, optimizing switching operations to reduce heat generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the switching elements are operated at high frequency to improve power conversion efficiency, then the power conversion speed is improved, but heat generation in the switching elements increases
Solution Approach 1:
The patent applies dynamics by making the carrier wave frequency variable rather than fixed. The control device dynamically adjusts the carrier wave frequency based on the absolute value of the difference between primary and secondary side frequencies. When frequency difference is large, higher carrier frequency is used for faster response; when frequency difference is small, lower carrier frequency reduces switching losses and heat generation.
Solution Approach 2:
The patent changes the parameter of carrier wave frequency adaptively. By modifying the carrier frequency parameter according to the frequency difference condition, the system optimizes the trade-off between power conversion speed and heat generation. This parameter change strategy allows the system to operate efficiently across different loading and frequency conditions.
2Measurement precision
If the carrier wave frequency is increased to improve control precision, then the alternating current tracking accuracy is improved, but the heat generation in switching elements increases
Solution Approach 1:
The system dynamically adjusts carrier frequency based on real-time frequency difference conditions. When high tracking precision is needed (large frequency difference), the carrier frequency is increased. When tracking precision requirements are lower (small frequency difference), the carrier frequency is reduced to minimize heat generation, thus dynamically balancing precision and thermal performance.
Solution Approach 2:
The carrier frequency parameter is changed adaptively according to the frequency difference between primary and secondary sides. This parameter modification allows the system to achieve high tracking accuracy when necessary while reducing switching losses and heat generation during normal operation, optimizing the precision-heat trade-off.
3Speed
If the switching elements are switched more frequently to improve power conversion control, then the control responsiveness is improved, but the reliability of switching elements deteriorates due to increased heat
Solution Approach 1:
The patent implements dynamic carrier frequency adjustment to balance responsiveness and reliability. When rapid control response is required (large frequency difference), the carrier frequency is increased for faster switching. When system is stable (small frequency difference), the carrier frequency is reduced to decrease thermal stress on switching elements, thereby maintaining reliability while preserving responsiveness when needed.
Solution Approach 2:
The switching frequency parameter is changed based on operational conditions. By adjusting the carrier frequency parameter according to frequency difference, the system achieves high control responsiveness when necessary while reducing cumulative thermal damage to switching elements, thus improving overall system reliability without sacrificing essential responsiveness.
Data Source
AI summary
A power conversion device 1 includes a matrix converter circuit 10 including a plurality of switching elements and being configured to perform bidirectional power conversion between alternating current power on a primary side and alternating current power on a secondary side, a power conversion control unit 114 configured to switch on and off the plurality of switching elements in unison with a carrier wave to cause an alternating current on the secondary side to follow a control command, and a carrier wave changing unit 116 configured to change, based on a nearness level between a frequency on the primary side and a frequency on the secondary side, a frequency of the carrier wave.