To ensure the limit values of voltage parameters it is necessary to use an accurate measuring instrument. There are several standards dealing with the measuring requirements as well as the measurement methods in details with the help of which the instrument showing the voltage parameters with authenticity can be made.
In the first part of the task I made some research on the essential parameters of the low-voltage power system concentrating on more important features and and measurement methods regarding the instrument. At the same time I learnt the basis of programming the processor using a developer panel. In the course of my studies I wrote indispensable algorithms to the instrument (measurement of period time, measurement of true RMS, digital filter algorithm).
Afterwards I made plans of the three-phase device that can be joined to the low-voltage system. Following this I made the algorithms necessary for measuring the voltage parameters as well as the method of how to registrate the measured quantities. Finally I computerised the control of the apparatus and worked out how the measured results can be read and processed.