Is it possible to save money at the nominal speed of the electric motor?

Very often there is a question of energy saving of a squirrel-cage induction motor, which operates at nominal speed. consumes the necessary current (which it would have consumed without frequency converter) as required by the technological process It is possible, but under certain conditions The fact is that recently many brands of manufacturers of frequency converters have appeared in the settings called as automatic energy saving, automatic energy saving optimization, etc. As a rule, this function is disabled at the factory settings , since its application requires some conditions. The idea of realizing this function is based on supplying the necessary voltage required to maintain a constant torque characteristic. motor loads over the entire speed range even up to 15 Hz This function also fully adapts the output voltage to the changing current load This also reduces the acoustic noise of the motor and power consumption To do this, as a rule, the function of automatic detection of motor parameters is used. The energy saving function works well for vector mode and for infrequently changing loads

Let's consider a real object on the example of a stone crusher drive in a quarry The crusher drive rotates at a frequency of 50 Hz If the motor is connected directly to the network, then when the load on the conveyor changes, the motor current changes, while the voltage is always 380V automatic correction of motor parameters, activated vector control and energy saving function, then when the load on the crusher changed, the current also changed proportionally to the load, and the motor supply voltage changed. In practice, this function can additionally save up to 35% of electricity. Below is a real output voltage graph at an output frequency of 50 Hz when working on the above mentioned mechanism

Thus, as you can see from the graph, the voltage on the motor does not rise above 350V This is the energy saving function. At this facility, the average savings amounted to 23% of electricity per year, which led to the payback of the solution for the 75 kW motor (even working at night tariff) 15 months

Thus, this function saves energy for drives operating in nominal mode. At the same time, the efficiency of the entire system is about 95-98% The share of the reactive component is minimalFor more detailed advice, you can contact our specialists in any available way in the section Contacts