Novosibirsk State Technical University (NETI) has developed a method for multi-stage predictive monitoring of the success of asynchronous motor start-up. The unique method, which has no analogues in Russia and abroad, makes it possible to ensure the reliable operation of local power supply systems with commensurate total generation capacity and large single engines.
NSTU-NETI has proposed a way to improve the operation of the local power supply system at the stage of starting an AC electric motor. The relevance of the topic was presented in the PhD thesis of Ilya Dulov, Senior lecturer at the Department of Automated Electric Power Systems at the Faculty of Energy.
Now there are more and more sources of distributed small-scale generation, on the basis of which active energy districts of electric networks, local intelligent energy systems, and local energy supply systems are being formed and developed. At the same time, single high-energy electric receivers (asynchronous motors) affect the operation of generating units and other loads. Uncontrolled start-up of large electric machines can lead to a violation of the balance of active and reactive power, which threatens to turn off generating units and cascade loss of stability of other engines.
A device that predicts the success of starting an asynchronous motor at an early stage of the process allows you to avoid negative consequences. Automation evaluates how successful the start of an electric machine is and monitors the process, which makes it possible to identify its feasibility in a short time interval in advance and, if conditions of failure are identified, interrupt them to protect both the machine and the system itself.
"Automation delays the external signal to turn on, checks the network parameters — whether they are acceptable or not. If the parameters are acceptable for a given time interval, an engine start command is generated. During the start-up process, the parameters of the engine and the supply network are determined, and the nature and degree of their changes are prognostically revealed. At each stage of the test, based on the results obtained, it becomes clear whether to continue the launch or not. In other words, we know what will happen next, and we can interrupt an unsuccessful start-up in a short interval in order to reduce the circuit—mode consequences in low-power power systems in case of unsuccessful starts of asynchronous motors," said Ilya Dulov, the author of the development.
Previously, predictive monitoring of the success of starting an asynchronous motor in the electric power industry was not carried out — you had to look at how the machine works after the fact. Without automation, visual inspection took a long time: the car might not start for a while, but it became known only later. The consequences of uncontrolled start-up of the asynchronous motor led to a decrease in voltage and frequency in the low-power system and, as a result, to disruption of the technological process and shutdown of power plants. For the first time, the development of NSTU-NETI makes it possible to monitor the success of machine start-up in real time.
"The development is needed to ensure reliable operation of local power supply systems of commensurate capacity in conditions of constantly changing structure and composition of generating equipment and load units," Ilya Dulov emphasized, adding that the method has already been patented and after testing the device will be ready for production. Energy companies are interested in developing NSTU-NETI. Another advantage is the cost of automation. According to preliminary calculations, according to the scientist, it is no more than 10% of the cost of the car itself.