Nowadays, with the rapid development of society, there are more and more styles. In order to meet the needs of frequency converter drive system and motor, many manufacturers have also produced different types of special motor for frequency converter. For ex/le, magnetic flux vector control frequency converter, current vector frequency converter, fan and water pump frequency converter, injection molding machine frequency converter, textile frequency converter, air compressor frequency converter, boiler application frequency converter and so on, so that many users do not know how to choose the appropriate frequency converter, do not know how to choose the frequency converter and so on. Today, Shijiazhuang frequency converter will talk about how to choose frequency converter.
1.Need to know what kind of equipment you need to use frequency converter, general frequency converter is divided into general-purpose frequency converter and special-purpose frequency converter; general frequency converter has a wide range of applications, suitable for mechanical use in most industries. The special-purpose frequency converter is one of the general-purpose frequency converters. On the basis of the general-purpose frequency converter, the special-purpose frequency converter carries out a series of special optimization according to the characteristics of the load driven by the frequency converter, and has a series of advantages, such as more simple parameter setting, better energy saving and speed regulation effect, etc.
2.You need to know how much power of the frequency converter; this one is relatively simple; that is, how many kilowatts of your equipment is equipped with as many kilowatts of frequency converter. At the same time, you can also increase the size of one model. For ex/le, 1.5kw motor can be equipped with 1.5kw frequency converter, but also can be equipped with a larger type of 5.5KW frequency converter. Generally speaking, it is equipped with a larger model, which is better. At the same time, if the load inertia is large, the braking unit and braking resistance should be selected at the same time. Then check the nameplate rated current of the motor, there is no nameplate rated current, the rated current of the frequency converter is larger than the maximum operating current of the motor.
3.The selection of frequency converter should determine the purpose of frequency conversion, constant voltage control or constant current control and so on. Choose according to the load type of the frequency converter, such as vane pump or volumetric pump, special attention should be paid to the performance curve of the frequency converter load, which determines the way and method of applying the frequency converter.
4.Frequency converter and load matching problem: the rated voltage of the frequency converter should be consistent with the rated voltage of the load. For the ordinary centrifugal pump, the rated current of the frequency converter should be consistent with the rated current of the motor, while for special loads such as deep water pump, it is necessary to refer to the motor performance parameters to determine the frequency converter current and overload capacity with the maximum current. Torque matching may occur under constant torque load or with a deceleration device.
5.When using frequency converter to drive high-speed motor, because the reactance of high-speed motor is relatively small, the increase of high-order harmonics will lead to the increase of output current, so the selection of frequency converters for high-speed motors should have a slightly larger capacity than the selection of ordinary motors
6.If the frequency converter wants to run with a long cable, measures should be taken to restrain the influence of the long cable on the ground coupling capacitance so as to avoid insufficient output of the frequency converter. In this case, the capacity of the frequency converter needs to be magnified by one gear or an output reactor is installed at the output of the converter; for some special applications, such as high temperature and high altitude, the converter will reduce its capacity. At this time, the capacity of the converter should also be magnified by one gear.
