In my master's thesis I present the development of a three-phase power quality measuring module, that belongs to the C-RTU product family developed by PROLAN Zrt. Using this family yields in small, modular, low-cost solutions, so the device to be developed had to be compact, cost-effective, without compromising accuracy.
First, I describe the concept of voltage and power quality, mentioning the relevant standards, measurement criteria and power line events. I present the development trends in power delivery systems, highlighting the ''Smart Grid'' concept, and the role of high performance electronics in it's evolution.
I introduce the C-RTU product family made by PROLAN Zrt., the advantages and special features of the system, then I discuss the subelements of the system, the base module, running Linux, and its capabilities, and the expansion modules, as well as their common features and functions.
As the first step in the product design, I present another device made by PROLAN Zrt., the ProField product family's three-phase voltage and current measurement module, AF500 as a reference for making the specification of the new module. During the design of the system, I present the different voltage and current measurement methods and data processing solutions, and then, after comparison, I present the system architecture of the measuring module.
I describe the hardware design steps, including component selections and dimensioning, schematic and PCB design. I pay special attention to the mechanical plans due to the compactness and special buildup of the module.
Software components are demonstrated first in the embedded environment, showing the custom structures and functions that are module specific. I show how the already written C-RTU specific software layers should be used, and how to access the various functions already developed. I show the capabilities of the host system's web based display, its simple configuration, and the steps of accurate calibration of the module through examples.
Finally, I present an actual application, illustrating the capabilities of the system, in particular, the performance of the measurement module.