Abstract This paper defines a criterion called the overall efficiency (OE) for evaluating the efficiency of acoustic sources. In practice, the conventional efficiency (CE), is not capable of giving a comprehensive overview of the power consumption, especially in the connected amplifier drivers. The reason for this is that the CE is defined based on the nominal input electrical power. The nominal input electrical power is defined as the real part of the power that is delivered by the electrical amplifier to the actuation unit of an acoustic source. Therefore, power loss in the amplifier unit is not included in the CE definition. With the aid of the OE criterion, the effect of power loss in the connected amplifier units is taken into account. In particular, the application of the OE is crucial for acoustic sources that operate in a low frequency range. This is due to the reactive nature of power in both actuators and connected amplifiers. In the current paper, various combinations of amplifiers and actuators are studied. In particular, voice coil actuators and piezoelectric stack elements including both Lead Zirconate Titanate (PZT) ceramics and single crystal Lead Zirconate Niobate-Lead Titanate (PZN-PT) piezoelectric materials are investigated. In addition, the effect of a connected power driver is investigated. A class AB and a class D amplifier are studied respectively as analogue and switching amplifiers. Unlike a class AB amplifier, a class D amplifier is capable of energy recovery. A perforated flat acoustic source is examined in this paper as a practical example to verify the OE criterion. The numerical simulation on a thin acoustic source shows that for a single actuator, thanks to energy recovery, the OE is higher in a class D amplifier than that in a class AB amplifier. This study reveals that if a class D amplifier is the driver, using piezoelectric actuators results in a higher OE compared to using a voice coil actuator. Measurements on the sample acoustic source verify the numerical results presented in the current study.

中文翻译：

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能量回收对低频声源整体效率的影响

摘要 本文定义了一个称为整体效率（OE）的标准，用于评估声源的效率。实际上，传统效率 (CE) 无法全面了解功耗，尤其是在连接的放大器驱动器中。这样做的原因是 CE 是根据标称输入电功率定义的。标称输入电功率被定义为由电放大器传送到声源驱动单元的功率的实部。因此，放大器单元中的功率损耗不包括在 CE 定义中。在 OE 标准的帮助下，所连接的放大器单元中的功率损耗的影响被考虑在内。特别是，OE 的应用对于在低频范围内工作的声源至关重要。这是由于执行器和连接的放大器中功率的无功性质。在当前的论文中，研究了放大器和执行器的各种组合。特别是，研究了音圈致动器和压电堆栈元件，包括锆钛酸铅 (PZT) 陶瓷和单晶锆钛酸铅-钛酸铅 (PZN-PT) 压电材料。此外，还研究了连接电源驱动器的影响。AB 类和 D 类放大器分别作为模拟和开关放大器进行研究。与 AB 类放大器不同，D 类放大器能够进行能量回收。本文以穿孔平面声源作为验证 OE 标准的实际示例进行了检查。对薄声源的数值模拟表明，对于单个执行器，由于能量回收，D 类放大器的 OE 高于 AB 类放大器的 OE。这项研究表明，如果 D 类放大器是驱动器，则与使用音圈致动器相比，使用压电致动器会产生更高的 OE。对样本声源的测量验证了当前研究中提出的数值结果。