Inverter Load Balancing via Gate Resistance Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-output inverter devices with parallel switching elements face issues of thermal runaway and unbalanced loads due to variations in element characteristics, leading to potential damage and improper operation, especially when loads become unbalanced between switching elements.
Innovation Solution
The inverter device is configured with switching elements and free wheeling diodes connected in parallel, where the processing circuitry monitors current and temperature to control loads and prevent unbalance by adjusting the gate resistance of transistors, ensuring that free wheeling diodes with the same characteristics are combined, and implementing a load control function to manage unbalanced losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If switching elements are connected in parallel to ensure current capacity, then the current handling capability is improved, but load unbalance and thermal runaway risk increase
Solution Approach 1:
The control circuit monitors the current flowing through each free wheeling diode and adjusts the gate resistance of corresponding transistors to balance the load distribution. This feedback mechanism detects load unbalance and dynamically compensates by modifying transistor characteristics, ensuring equal current sharing among parallel switching elements.
Solution Approach 2:
The invention dynamically changes the gate resistance parameter of transistors to adjust their conducting characteristics. By varying the gate resistance, the control circuit modifies the transistor's on-state resistance and current distribution, thereby balancing the load among parallel switching elements with different characteristics.
2Power
If switching elements operate under high load, then the power output is improved, but heat generation and thermal runaway risk increase
Solution Approach 1:
The control circuit monitors temperature or current of each switching element and adjusts gate resistance in real-time to prevent thermal runaway. When an element shows signs of excessive heating or current concentration, the feedback mechanism increases its gate resistance to reduce current flow, thereby controlling heat generation while maintaining high power output.
Solution Approach 2:
The invention implements preventive load balancing to avoid thermal runaway before it occurs. By continuously monitoring and adjusting gate resistance to maintain equal current distribution, the system prevents the conditions that lead to thermal runaway, cushioning against potential damage before it happens.
3Adaptability or versatility
If free wheeling diodes with different characteristics are used, then device flexibility is improved, but load unbalance occurs
Solution Approach 1:
The control circuit measures the current through each free wheeling diode and adjusts the gate resistance of associated transistors to compensate for characteristic differences. This feedback mechanism allows the use of diodes with varying characteristics while maintaining balanced load distribution by dynamically equalizing current flow.
Solution Approach 2:
The invention applies individualized gate resistance adjustment to each switching element based on its specific characteristics and load conditions. By tailoring the gate resistance locally for each transistor-diode pair, the system compensates for manufacturing variations and characteristic differences, enabling flexible component selection without compromising load balance.
Data Source
AI summary
An inverter device according to an embodiment includes a plurality of switching elements and processing circuitry. The switching elements are connected to each other in parallel, and each of them includes a transistor and a free wheeling diode connected to the transistor in antiparallel. The processing circuitry is configured to monitor a current flowing through the free wheeling diode included in each switching element or a temperature of the free wheeling diode and to control, in accordance with the current or the temperature, a load on each free wheeling diode to prevent unbalance of loads between free wheeling diodes in the switching elements.