ARCPI Boosting Time Correction for Saturable Inductor Nonlinearity
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Solution Overview
Problem
The use of saturable inductors in PWM ARCPIs impairs the accuracy of current controllability due to their non-linearity, leading to inaccuracies in boosting current controlled through auxiliary semiconductor devices.
Innovation Solution
A method and device for determining the boosting time in the auxiliary switch path of a PWM ARCPI, which includes calculating a first boosting time based on theoretical resonance inductance and voltage, and determining a second boosting time from a look-up table, to correct the boosting time considering the non-linearity of the saturable inductor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a saturable inductor is applied to mitigate excessive transient voltage in the auxiliary semiconductor devices, then the voltage protection is improved, but the accuracy of current controllability through the auxiliary semiconductor devices is impaired
Solution Approach 1:
The patent implements a feedback mechanism where the controller measures the actual current through the auxiliary semiconductor devices and compares it with the desired current. Based on this comparison, the controller adjusts the gating signal timing to compensate for the non-linearity effects of the saturable inductor, thereby maintaining accurate current controllability while preserving voltage protection.
Solution Approach 2:
The patent changes the operating parameters of the saturable inductor by controlling the timing of the gating signals to the auxiliary semiconductor devices. By dynamically adjusting the turn-on and turn-off times of the auxiliary switches, the system adapts to the non-linear characteristics of the saturable inductor at different current levels, maintaining both voltage protection and current accuracy.
2Reliability
If the auxiliary semiconductor devices boost precise current prior to each commutation instant, then the zero-voltage switching is achieved, but the use of saturable inductor adds inaccuracies to the boosting current
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing the relationship between desired current and actual current delivered through the saturable inductor in lookup tables. Before each commutation event, the controller queries these pre-computed values to determine the appropriate gating signal timing, ensuring accurate current boosting while maintaining zero-voltage switching conditions.
Solution Approach 2:
The controller continuously monitors the actual current waveform and uses feedback to adjust the gating signal timing. This feedback mechanism compensates for the inaccuracies introduced by the saturable inductor's non-linearity, ensuring that the precise current boosting required for zero-voltage switching is achieved despite the inductor's non-ideal characteristics.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method provides more accurate boosting current levels in the auxiliary switch path by correcting the boosting time, thereby improving the accuracy of current controllability and maintaining the advantages of zero-voltage switching and reduced switching loss.
Implementation Method 1
a saturable inductor is applied in a PWM ARCPI to mitigate excessive transient voltage in the auxiliary semiconductor devices
Implementation Method 2
A pulse width modulation (PWM) auxiliary resonant commutated pole inverter (ARCPI) is often used to achieve soft switching
Data Source
AI summary
A method for an auxiliary device of an auxiliary resonant commutated pole inverter (ARCPI) to determine a boosting time of the ARCPI is provided. The auxiliary device includes an auxiliary switch path that uses a resonant inductor with at least one saturable inductor. The method includes: calculating, by a processor of the auxiliary device, a first boosting time in the auxiliary switch path based on a theoretical resonance inductance and a voltage that are applied to the resonant inductor; determining, by the processor, a second boosting time in the auxiliary switch path based on a look-up table; and determining, by the processor, the boosting time in the auxiliary switch path based on the first boosting time and the second boosting time. The method further includes controlling, by the processor, boosting current of the ARCPI based on the boosting time in the auxiliary switch path.