In modern industry, frequency converters are increasingly used. However, in some cases, a standard-capacity frequency converter may not meet actual needs. In this case, it is necessary to consider increasing the capacity of the frequency converter. The following are some typical situations where the frequency converter capacity needs to be increased:
1. The rated current of the inverter is too low
When the rated current of the inverter is lower than the rated current of the motor of the same capacity, a higher-level inverter should be selected according to the load of the motor. This is because the inverter needs to provide sufficient current to drive the motor to ensure its normal operation.
2. The motor may be overloaded for a short time
When the motor is overloaded for a short time, the overload capacity of the inverter is usually 150% for 1 minute. In contrast, the motor overload time may be as long as several minutes or even tens of minutes. Therefore, if the motor may be overloaded for a short time, the capacity of the inverter should be increased to ensure that it can withstand this load.
3. Special requirements for acceleration and deceleration time
The acceleration time of the motor is related to the inertia of the load. For example, for a load with large inertia, the acceleration time may need to be longer, while for a load with small inertia, the acceleration time may be shorter.
Generally speaking, for loads that need to start and stop under heavy load, the capacity of the inverter should be increased in the following cases:
(1) Those that require fast starting and stopping;
(2) Those that require frequent jogging.
4. There is an impact load
When the motor and the load are connected through the clutch, an impact load will be generated at the moment of clutch connection, causing the motor speed to drop and the current to increase, which may trigger overcurrent protection. In this case, the capacity of the inverter should be increased to cope with the impact load and ensure stable operation of the system.
Summary
In the following cases, you should consider increasing the capacity of the inverter:
The rated current of the inverter is too low.
The motor may be overloaded for a short time.
There are special requirements for acceleration and deceleration time.
There is an impact load.
By reasonably selecting the capacity of the inverter, you can ensure the stable operation of the motor and inverter and improve the reliability and efficiency of the system.