Advantages and disadvantages of variable frequency starting The variable frequency starting current is several times the rated current

Advantages and disadvantages of variable frequency starting

Frequency conversion starting is a common motor starting method. Its advantages and disadvantages are as follows:

advantage:

1. Small starting current: During the starting process, the inverter can gradually increase the output frequency and voltage, allowing the motor to start slowly from a low speed. The motor starting current is small and the starting is smooth.

2. Energy saving and environmental protection: Compared with the traditional direct starting method, variable frequency starting can save a lot of energy and reduce environmental pollution.

3. Low maintenance cost: Since the starting current of the motor is small during startup, the damage to the motor, transmission mechanism, etc. is reduced, which extends the service life of the equipment. At the same time, the operation is stable and the maintenance cost of the equipment is reduced.

4. Adjustable speed: The inverter supports adjustment of the motor speed. The rated output power and speed can be adjusted according to different working conditions and needs to meet different working requirements.

shortcoming:

1. Because additional inverter equipment is required, it takes up a certain amount of space and increases the equipment cost.

2. It is not cost-effective to use it on small equipment with low economic benefits, and it may even be a waste of energy.

3. The inverter will generate certain noise and electromagnetic interference, which may affect the normal operation of other equipment.

4. Due to the complexity of the circuit, the equipment maintenance requires professional personnel to maintain and manage, and the maintenance is difficult.

In short, variable frequency starting has many advantages, such as small starting current, energy saving and environmental protection, low maintenance cost, etc., but it also has certain disadvantages, which need to be comprehensively considered according to specific occasions.

How many times is the variable frequency starting current the rated current?

The current during variable frequency starting is usually determined by many factors such as the load properties at startup, the settings of the inverter, and the characteristics of the motor. Therefore, the current during variable frequency starting is not a fixed value. When the inverter starts the motor, the output voltage and frequency will gradually increase from zero to the rated voltage and frequency. During this process, the current received by the motor will gradually increase. The current depends on the size of the electromagnetic torque during the starting process. In general, the current of the variable frequency starting motor may exceed its rated current by about 3 times.

After the inverter starts the motor, the current may change according to the load. Generally speaking, when the inverter adjusts the load, if the load increases, the motor speed will slow down, and a larger current is required to maintain the motor torque and output power. Conversely, if the load decreases, the motor speed will increase, and the current will decrease accordingly.

In short, when the motor is started by variable frequency, the current size is a dynamically changing process, which needs to be comprehensively considered according to the actual situation to avoid motor overload or other unexpected problems.