Inner Converter Control for Power Converter Efficiency
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Solution Overview
Problem
Power converters using isolation transformers experience significant losses and thermal constraints, limiting efficiency and increasing costs due to continuous operation of inner converters even when outer converter output voltage is zero, leading to unnecessary heating and reduced power density.
Innovation Solution
Implementing a control method that determines the output voltage of the outer converter and controls the inner converter to an off state when the output voltage is zero, reducing power flow through the isolation transformer during periods of zero output, thereby minimizing core losses and heat generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the inner converter operates continuously to maintain power conversion capability, then the system can respond quickly to load changes, but core losses and heat generation increase significantly
Solution Approach 1:
The inner converter's operation state is dynamically adjusted based on real-time monitoring of the outer converter's output voltage. When output voltage is detected as zero, the inner converter transitions to an off state; when non-zero, it operates. This dynamic state switching resolves the contradiction by adapting the system's operational characteristics to actual load conditions, achieving both rapid response capability and energy efficiency.
Solution Approach 2:
The operational parameter of the inner converter (on/off state) is changed based on the output voltage parameter of the outer converter. By monitoring and responding to voltage parameter changes, the system optimizes energy loss without sacrificing response capability, as the converter can quickly transition between states when voltage conditions change.
2Reliability
If the inner converter operates continuously, then power conversion readiness is maintained, but thermal constraints are exceeded and cooling requirements increase
Solution Approach 1:
The system dynamically adjusts the inner converter's operational state based on thermal and voltage conditions. By switching the converter off during zero-output periods, thermal generation is reduced while maintaining the capability to quickly resume operation when voltage conditions indicate load demand, thus managing thermal constraints without permanently sacrificing reliability.
3Power
If the inner converter operates continuously, then the system maintains full power conversion capability, but system cost and power density are reduced
Solution Approach 1:
The operational state parameter of the inner converter is changed from continuous operation to conditional operation based on outer converter voltage. This parameter change eliminates unnecessary power consumption during zero-output periods while preserving full power conversion capability when voltage conditions indicate active load requirements, thereby improving power density and reducing energy waste.
Data Source
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AI summary
Systems and methods for operating a power converter are provided. A DC to AC converter can include an inner converter and an outer converter. The inner converter can include an isolation transformer a first plurality of switching devices. The outer converter can include a second plurality of switching devices. A control method can include determining an output voltage of the outer converter. The control method can further include controlling operation of the inner converter based at least in part on the output voltage of the outer converter.