Computer-controlled machines represent the foundation of modern mass production, operating non-stop to achieve the required output of products. However, as with any other electro-mechanical device, such machines are also prone to wearing out with time. This can lead to various errors, which may occur continuously or only intermittently. The most difficult errors to detect are those that occur only once over a long period of time, or with non-repeatable and unexpected occurrence. In order to detect and analyze such errors, we hence decided to create a measurement device, designed to detect faults on three-phase systems.
The presented device can be installed between the three-phase inverter and the axle drive motor, allowing it to monitor voltages and currents on all three phases simultaneously. Based on the acquired voltages and currents, we can then determine the condition of the entire three-phase system at any given time.
This diploma thesis focuses on the presentation of the development process for such a measuring circuit, along with any problems encountered; these were solved during design phase. Initially, detected errors were determined, and the corresponding sensing approaches were selected. This was subsequently followed by a description of the development process and analysis of individual parts of the final version of the circuit. In addition to the measuring unit, this diploma thesis presents the circuit of the central unit, which serves to centralize the system and facilitate access to data. Simultaneously with hardware development, microprocessor code development is also presented. Finally, a comparison of oscilloscope and module acquired measurements is given.
|
