DETERMINATION OF EMERGENCY REGIMES OF ELECTRIC MOTORS BY MEANS OF MODERN SYSTEMS OF DIAGNOSING THEIR CONDITION

Abstract

Electric motors are usually designed for a service life of 15… 20 years without major repairs, provided they are properly operated. Proper operation means operation in accordance with the nominal parameters specified in the passport data of the motor. However, in practice there is a significant deviation from the nominal modes of operation. These are, first of all, low quality of supply voltage and violation of rules of technical operation: technological overloads, environmental conditions (high humidity, temperature), decrease in insulation resistance, cooling disorders.
 The consequence of such deviations are emergency modes of operation of electric motors. In some subsectors of the industry, the accident rate of electric motors ranges from 20 to 50% per year. Failure of the motor leads to severe accidents and significant material damage due to downtime, the cost of troubleshooting and repair of the failed motor. Repair of an electric car with a capacity of 1 kW costs 550-700 UAH. To estimate the cost of repairing a more powerful machine, you need to multiply this figure by the engine power. In addition, operation in emergency modes leads to increased energy consumption and increased reactive power consumption.
 One of the promising types of protection against emergencies is the use of modern diagnostic systems with the function of monitoring the signs of emergencies. Therefore, the urgent task is to eliminate the shortcomings of protection devices through the use of modern intelligent systems for diagnosing their condition.
 The task is to determine the set of diagnostic features of emergency electric modes of induction motors for the application of these features in the systems of functional diagnostics of energy and technical condition of the engine and increase the reliability of establishing the characteristic types of damage.
 The article considers a set of signs of emergency electrical modes for different types of damage to induction motors. These features can be used in modern systems for diagnosing energy efficiency and technical condition of electromechanical systems, which can also perform the function of protecting electric motors from emergency modes.