Zero-Voltage Switching for Reliable Power Inversion Circuits
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Summary
Problems
Conventional power inversion circuits face high switching losses and potential shoot-through problems in MOSFETs, limiting high power density performance and complicating controller design due to high frequency hard-switching operations and noise issues.
Innovation solutions
The implementation of a TT control scheme with two driver signal pairs, one near 50% duty cycle and one pulse-width modulated, reduces the shoot-through problem and enhances reliability by allowing zero-voltage switching (ZVS) operation, thereby reducing switching losses and improving circuit reliability.
TRIZ Analysis
Specific contradictions:
General conflict description:
Principle concept:
If phase-shift control scheme is used to reduce switching loss, then ZVS operation is achieved, but shoot-through problem on MOSFETs increases
Why choose this principle:
The patent applies preliminary action by introducing a dead-time interval before the complementary MOSFET turns on, during which the first MOSFET is turned off. This preliminary turn-off action prevents shoot-through current by ensuring the first MOSFET is completely off before the second MOSFET turns on, while still allowing ZVS to occur during this dead-time period through energy exchange between the inductor and MOSFET output capacitance.
Principle concept:
If longer dead-time interval is increased to reduce shoot-through problem, then reliability improves, but available operating frequency decreases
Why choose this principle:
The patent applies parameter changes by optimizing the dead-time interval to a specific range (50ns-200ns) that balances two competing requirements: it is long enough to allow complete turn-off of the first MOSFET and prevent shoot-through, but short enough to minimize the impact on operating frequency. This optimized parameter enables both high reliability and high-frequency operation (above 100kHz).
Application Domain
Data Source
AI summary:
The implementation of a TT control scheme with two driver signal pairs, one near 50% duty cycle and one pulse-width modulated, reduces the shoot-through problem and enhances reliability by allowing zero-voltage switching (ZVS) operation, thereby reducing switching losses and improving circuit reliability.
Abstract
To disclose several zero-voltage-switching (ZVS) power inversion circuits, a modified pulse-width modulation control scheme is employed. It includes two driver-signal pairs. Each pair has a near 50% duty ratio driver signal and a pulse-width modulation driver signal. Because the combination timing waveform of the two driver signals of each pair resembles to a letter T, the control scheme is thus briefly named as double T (TT) control. In addition to achieving zero-voltage switching performance for high frequency operation, the disclosed power inversion circuits can alleviate the potential shoot-through problem existed in phase-shift control full-bridge power inversion circuits. Consequently, reliability performance can be improved.