Parallel Power Converter Current Balance Timing Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power converter apparatuses with parallel-connected power semiconductor devices face current unbalance due to manufacturing variations, leading to increased switching losses, heat dissipation issues, and limitations in downsizing, as well as higher manufacturing costs and space requirements due to the need for complex control circuits and insulation.
Innovation Solution
A power converter apparatus comprising first and second power converter circuits, a control circuit, a timing control signal generator circuit, and a timing correction circuit, which uses a logic circuit to compare currents and generate timing control signals to correct the rise and fall of control signals, thereby balancing current flow without requiring ICs or insulation-type current detectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If proportional integration control is implemented to suppress current unbalance, then current distribution is improved, but circuit complexity and mounting space increase due to requiring DSP/microcomputer and AD converter
Solution Approach 1:
The patent replaces complex digital signal processing (DSP/microcomputer) and analog-to-digital conversion circuits with a simple analog timing correction circuit that directly processes current difference signals. This substitution of complex electronic systems with a simpler analog circuit resolves the contradiction by maintaining current balance control functionality while dramatically reducing circuit complexity and mounting space requirements.
Solution Approach 2:
The patent creates a simplified copy of the proportional integration control function using basic analog components (amplifiers, integrators, and timing circuits) rather than implementing the full digital control algorithm. This analog copy achieves the essential current balancing effect without requiring complex digital processing hardware, thereby resolving the contradiction between control effectiveness and circuit simplicity.
2Measurement precision
If insulation type current detector is used to detect output current, then measurement accuracy is improved, but manufacturing cost increases
Solution Approach 1:
The patent employs simple current detectors without insulation requirements instead of expensive insulation type current detectors. By using basic sensing elements that directly measure current without requiring electrical insulation, the system achieves sufficient measurement precision for control purposes while dramatically reducing component cost and simplifying manufacturing.
Solution Approach 2:
The patent designs the current detection system to be inherently safe and functional without requiring additional insulation components. The detection circuit is integrated into the power converter structure such that the detection function is achieved through the existing circuit topology, eliminating the need for separate insulated detectors and reducing overall system cost.
3Temperature
If large-sized heat dissipation fin is used to suppress heat generation, then thermal management is improved, but device size increases making downsizing difficult
Solution Approach 1:
The patent implements preliminary timing correction to prevent current unbalance before it occurs. By adjusting the switching timing of parallel power semiconductor devices in advance, the system prevents excessive current concentration that would generate heat, thereby reducing the required heat dissipation capacity and enabling smaller thermal management components.
Solution Approach 2:
The patent converts the potential harmful effect of current unbalance (which causes heat generation) into a controllable parameter by using timing correction. By deliberately adjusting switching timing, the system prevents current unbalance and its associated heat generation, effectively transforming a potential problem into a controlled aspect of device operation that enables compact design.
Data Source
AI summary
In a power converter apparatus, a first power converter circuit is configured of first power semiconductor devices, and a second power converter circuit is connected in parallel to the first power converter circuit, and is configured of second power semiconductor devices. A control circuit generates a control signal for controlling each power semiconductor device of the first and second power converter circuits. A timing control signal generator circuit compares a first amount of current flowing through the first power semiconductor devices with a second amount of current flowing through the second power semiconductor devices, and generate a timing control signal for controlling a timing of a rise or a fall of each of the control signals inputted to the first and second power converter circuits, based on a comparison result. A timing correction circuit controls the control signals to correct the timing of the rise or the fall thereof.