# Parametric and Experimental Modeling of Axial-Type Piezoelectric Energy Generator with Active Base
## 1 Introduction  
At present, in connection with their development and introduction into production, renewable electrochemical batteries are used to the greatest extent. These electric batteries have the properties of cyclic recovery during a certain resource period and are limited in use when a certain finite operating time is reached [1, 2]. Along with renewable batteries, promising devices are used that extract electrical energy from the environment. One of the directions is the extraction of electric energy using solar energy. Some approaches can be presented as examples described in works using solar batteries [3, 4]. The energy of the environment in the form of vibration entering compact devices can be extracted using the energy of the movement of air masses (wind), including using energy generation devices in the form of piezoelectric transducers [5, 6]. The use of the mechanical energy of the movement of water masses in narrowed volumes, sea tides and tides, and the movement of water masses of rivers and dams, can be represented by the example of [7]. The use of devices for converting thermal energy into electrical energy is presented in [8]. Devices for converting mechanical vibrations of structural elements and soils are presented in the reviews of works [9, 10]. Devices for generating electrical energy, the so-called power converters of mechanical energy into electrical energy, using piezoelectric elements, are called piezoelectric generators (PEGs). Their development requires further modernization and improvement. This ispossible only when designing new devices and analyzing their operation under various conditions of dynamic loading. As a review of the current use of PEG shows, such devices require further development due to the low output power and voltage generated. Basic information about energy generators, as well as problems arising in the development of energy storage devices using piezoelectric elements, were discussed in review articles [11; 12; 13; 14; 15]. The primary analysis of review articles shows that models are considered that use piezoelectric elements operating in compression and buckling with tension. Piezoelectric elements can be built into various mechanisms using both pressure and rotational loads. The reviews present the output characteristics of PEG energy of various types of manufacture. Monographs [16; 17] present theoretical works by some authors. Methods for conducting experimental studies are given. As the literature reviews [12; 13; 14; 15; 16; 17] show, the most common element in the generator is a cantilever or a linear type element that is fixed at one or two points. There are schemes with fastening of bending elements in the form of a truss structure. A mass or element in the form of a magnetic attachment is attached to some end or intermediate part of such a device. An electrical load in the form of capacitance C, resistance R or inductance L can be applied to each piezoelectric element separately. Typically, a single-component electrical load is used, which has a certain resistance. In [18], the main topologies of load-relief circuits in the form of electrical energy with the simplest composite circuit of a voltage rectifier in the form of a diode bridge are given. Within the framework of the presented work, it is supposed to measure the voltage at individual electrodes. Thus, under dynamic loading, it is possible to investigate the phase characteristics of the removed potential and the potential on each individual piezoelectric element. The research in paper [19] proposed a novel hybridization scheme with electromagnetic transduction to enhance the power density of PEHs. The hybrid energy harvester was designed based on the BC-PEH. To compare the power density of the BC-PEH and the hybrid energy harvester, we built a prototype and conducted many experiments. The generator delivers a high voltage of 21.9 V at a drive acceleration of 0.3 g using an array of variable magnets. A peak output power of 103.53 mW is obtained.