This article proposes a novel mean for tuning the natural frequency of an electromagnetic resonant shunt, using a pulse-width modulation (PWM) circuit. It is used to modulate the value of the capacitance of the shunt, and the electrical frequency is shown to be proportional to the command parameter of the PWM, the duty cycle. An easy and efficient strategy to tune the resonant shunt in real time is then proposed, thus obtaining a low powered and always stable vibration control device. The article proposes the theory of PWM, giving a robust method to predict the dynamics of the system. Then, an accurate multi-mode theoretical model of the tunable resonant shunt coupled to an elastic structure is proposed and experimentally validated on an elastic multi-mode structure, in the case of two different control strategies. The first one is a standard resonant shunt with both the electrical frequency and damping optimized to reduce a given resonance peak. The second one is based on a resonant shunt with the electrical damping as low as possible, which creates an antiresonance and a “notch” type mechanical response at the driving frequency. Both strategies are experimentally validated with real time variation and adaptation of the electrical frequency, obtaining an efficient vibration control device, able to reduce by a factor 40 the vibration level.

本文提出了一种使用脉宽调制（PWM）电路来调谐电磁谐振分流器固有频率的新颖方法。它用于调制分流器的电容值，并且电气频率与PWM的命令参数即占空比成正比。因此，提出了一种简单有效的实时调谐谐振分流器的策略，从而获得了一种低功率且始终稳定的振动控制装置。本文提出了PWM理论，为预测系统的动态特性提供了一种可靠的方法。然后，在两种不同的控制策略的情况下，提出了一种与弹性结构耦合的可调谐振分流器的精确多模理论模型，并在弹性多模结构上进行了实验验证。第一个是标准谐振分流器，其电气频率和阻尼均经过优化以减小给定的谐振峰值。第二种基于谐振分流器，其电阻尼应尽可能低，从而在驱动频率下产生反谐振和“陷波”型机械响应。两种策略均通过实时变化和电频率调整进行了实验验证，从而获得了一种有效的振动控制设备，该设备能够将振动水平降低40倍。