Theoretical basis for combining thermo-hydraulic and thermo-electric power conversion into one unit - thermo-hydraulic linear generator

迄今为止，液压是移动机械中首选的动力转换和传输类型。多年来，申请人已经成功地开发了一种简单而廉价的用于移动液压混合动力技术的热液压自由活塞发动机（FKM）驱动单元，它能够高效地为机器提供所需的液压推进动力，并尽可能低地排放。当前电气工程的发展促进了新应用的发展。取代传统驱动器的原因是提高了能源效率和/或改善了可控性。因此，出于功能和能量的原因，在一个初级单元中同时提供液压和电力是未来移动机器的理想选择。该研究项目的目的是为将热电和热电结合成一个单元（热电线性发电机- THLG）提供理论基础，以获得技术实现和技术复杂性的可靠估计。在自由活塞原理的基础上，水力和电力同时按比例自由选择供电在原则上是可能的。然而，这需要对两种能量转换之间的相互作用进行基础研究，稳定的过程控制，以及与未来原型设计有关的物理过程参数的分析和评估。根据特定要求，从FKM的合适系统配置出发，开发了一种优化功率密度并适应现有样机的线性发电机。两种功率转换的组合需要一种协调的控制策略，这可以从子系统之间的相互依赖关系和整个系统的动态行为中得到。这些必须允许满足要求的功率输出，并且在液压和电气方面同时可变，并确保稳定运行。为此目的，将研究子系统线性发电机内平稳运行的不同调节方法，这是有条件的原则，以及整个系统THLG的高动态行为。为了保持较低的硬件成本，无传感器位置检测是首选，因为线性机器的控制需要精确的移动位置知识。针对THLG的具体应用，分析了混合无传感器方法在整个速度范围内的可能适应性。结果是关于THLG的详细信息，以及它是否可行以及在何种技术努力下可行。它们既包括能量学问题，也包括控制问题。

Hitherto, hydraulics is the preferred type of power conversion and transmission in mobile machinery. For years, at the applicants, they have successfully been dealing with the development of a simple and inexpensive drive unit of the thermo-hydraulic free piston engine (FKM) for mobile hydraulic hybrid technology, which is capable of providing the required hydraulic propulsion power to the machine as efficiently and with as low-emissions as possible. Current developments in electric engineering enable the development of new applications. The reasons for replacing conventional drives are the increased energy efficiency and / or the improved controllability. Therefore, out of functional and energetic reasons, the simultaneous supply of hydraulic and electric power in a primary unit for future mobile machines is desirable. The aim of the research project is to provide the theoretical basis for combining thermo-hydraulic and thermo-electric power conversion into one unit (thermo-hydraulic linear generator - THLG) in order to obtain a reliable estimate of the technical realisation and the technical complexity. The simultaneous and in its ratio freely selectable supply of hydraulic and electric power on the basis of the free piston principle is possible in principal. However this requires fundamental research concerning the interaction between both energy transformations, of a stable process control as well as the analysis and assessment of the physical process parameters concerning the future design of a prototype. Starting from a suitable system configuration of the FKM under specific requirements, a linear generator which is optimized in power density and adapted to the existing prototypes is developed. The combination of both power conversions requires a coordinated control strategy, which can be derived from the dependencies of the subsystems with each other and the dynamic behavior of the whole system. These must allow a power output which meets the requirements and is simultaneous and variable on the hydraulic and the electric side as well as ensure a stable operation. For this purpose different regulatory approaches for the inner-stationary operation of the subsystem linear generator, which is conditional to principles, and the highly dynamic behavior of the complete system THLG are to be investigated. In order to keep hardware costs low, sensorless position detection is preferred, since the control of the linear machine requires an exact knowledge of the position of the mover. The possible adaptation of hybrid sensorless methods over the whole speed range is analysed for the specific application THLG. The result is detailed information on a THLG, whether and under which technical efforts it is practicable. They include both, issues of energetics and control.