In fact,the main reason why the inverter will jump off is low frequency,poor heat dissopation,motor heating,and insufficient heat dissipation when the general motor's own wind blade is low frequency.The heating temperature is not enough to overload the boot,causing the inverter to jump or burn the motor.Improper adjustment of frequency converter parameters will also jump,the focus of improvement is the choice of motor and frequency converter,the expensive is not the best,the important thing is that the motor and frequency converter should be tacit.
So how to choose a good motor and frequency converter?
Selection of motor
First of all,it is necessary to select the power of the motor according to the average power and maximum power required by the load movement,which is converted to the motor shaft side (there may be reducers,pulley and other deceleration devices),and also consider the overload capacity of the motor.General motor manufacturers can provide the torque characteristic curve of the motor,the motor characteristics will change at temperatures,you can refer to the manual provided by the manufacturer.
Tips:When choosing the collocation,the motor should be selected first and then the inverter should be selected according to the motor,because the ultimate purpose of control is not the inverter nor the motor,but the mechanical load capacity.
Selection of frequency converter
First,the selection is based on current.For ordinary loads,the corresponding frequency converter is selected according to the rated current of the motor,that is,the rated current of the frequency converter (that is,the maximum continuous working current in the conventional environment) is greater than the rated current of the motor.However,some special cases should also be considered,so the inverter also needs to be able to provide a short period of overload current ability.
(Note:The current of the motor is determined by the mechanical load) The inverter has an overload current curve,which is an inverse time curve,indicating the curve relationship between overload current and time.Inverter manufacturers often indicate that the overload capacity can reach 150% rated current for 2 seconds,and 180% rated current for 2 seconds,which is actually a curve.In fact,as long as the current curve of the motor is within the range of the overload current curve of the inverter,there is generally no problem.That is why sometimes the inverter power is greater than the motor power 1 or 2 (such as lifting applications),but sometimes the low-power inverter can still drive high-power motors (such as conveyor belts).
It should be noted that in some special conditions,such as high altitude,high ambient temperature (such as greater than 50 degrees less than 60 degrees),side-by-side installation mode (some inverters installed side-by-side do not reduce capacity,some to reduce capacity,according to the inverter design decision),but also need to consider the capacity reduction of the inverter.This aspect of the data inverter manufacturers can provide.Conclusion:The rated power of the inverter may be greater than the motor power,in fact,the selection of the inverter is also determined by the mechanical load capacity.
