Ring-Connected Inverter Circuit Without High-Side Switches
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Solution Overview
Problem
Conventional inverter circuits face limitations such as fixed output voltage, high-side driver voltage constraints, dead time reduction, reliability issues due to high dv/dt, and complex control algorithms, particularly in higher voltage applications.
Innovation Solution
An inverter circuit design without high-side power transistors, utilizing a ring configuration of inverter modules with pre-filter, mid-filter, and signal output circuits, and chopper components to achieve higher voltage and power output, enhancing reliability and simplifying control algorithms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional half-bridge or full-bridge structures with high-side power transistors are used, then proper switching control can be achieved, but the output voltage is constrained by the supply voltage and driver circuit complexity increases
Solution Approach 1:
The patent removes the high-side power transistor from the conventional half-bridge or full-bridge structure, extracting the problematic component that limits output voltage and increases driver complexity. This leaves only the low-side power transistor, which can be directly controlled by PWM signals without requiring voltage higher than the supply voltage.
Solution Approach 2:
Instead of using the conventional approach where high-side and low-side transistors work together with complex driver circuits, the patent inverts the approach by using only the low-side transistor with a modified circuit topology. The output voltage is generated through the interaction of multiple such simplified modules rather than through a single complex bridge structure.
2Power
If high-side power transistors are used for pull-up operation, then proper output voltage generation is achieved, but reliability decreases due to high dv/dt causing parasitic capacitance effects and unwanted gate triggering
Solution Approach 1:
The patent removes the high-side power transistor that causes high dv/dt problems, eliminating the source of parasitic capacitance effects and unwanted gate triggering. This extraction improves reliability while maintaining output voltage generation capability through the modified circuit topology.
3Reliability
If dead time is introduced to prevent simultaneous conduction of high-side and low-side transistors, then short circuit prevention is achieved, but power output decreases
Solution Approach 1:
By removing the high-side power transistor, the patent eliminates the need for dead time control between high-side and low-side transistors. The simplified topology with only low-side transistors avoids the simultaneous conduction issue entirely, allowing continuous operation without power loss from dead time.
Data Source
AI summary
An inverter circuit and inverter module without high-side power transistors are provided. The inverter circuit consists of at least two inverter modules connected in a ring structure. Each inverter module includes: A pre-filter circuit, having a signal input terminal and a signal output terminal, wherein the signal input terminal serves as the modulation signal input terminal; A central filter circuit, including a DC power input terminal and an AC power output coil, with the signal input terminal of the central filter circuit connected to the signal output terminal of the pre-filter circuit; A signal output circuit, with its signal input terminal connected to the signal output terminal of the central filter circuit, and its signal output terminal serving as the modulation signal output terminal. The inverter circuit and the inverter module enable a significant reduction in inverter costs and simplifies the controller algorithm.