What are the types of frequency converters? What are the types of frequency converters

According to different classification criteria, frequency converters can be divided into many different types. Here are some common classifications of drives:

Classification by motor type: It can be divided into AC motor inverter and DC motor inverter.

Classification according to output power: it can be divided into low-voltage inverter (output power is generally below several kilowatts), medium-voltage inverter (output power is generally between tens of kilowatts and hundreds of kilowatts) and high-voltage inverter (output power is generally more than hundreds of kilowatts).

Classified according to the mode of grid connection: it can be divided into independent inverter and grid-side inverter. Stand-alone drives are mainly used for individual loads such as fans, pumps, etc., while grid-side drives are mainly used in power systems as part of power electronics.

Classified according to the inverter topology: it can be divided into SPWM inverter based on PWM technology, MLI inverter based on multi-level technology, resonant inverter based on resonant technology, etc.

Classification according to application: it can be divided into general frequency converter and special frequency converter. Universal drives are suitable for a wide range of applications, while specialized drives are designed and manufactured for specific applications.

The above are just common classifications of frequency converters, in fact, there are many other classifications, such as control mode, input voltage, and so on. Different types of inverters are suitable for different applications, and users need to choose according to the specific situation when choosing inverters.

There are three main types of high-performance general-purpose inverters: the first is a vector-controlled inverter with a speed sensor; the second is a vector-controlled inverter without a speed sensor; The third type is a direct torque control inverter without a speed sensor. The first of these three high-performance inverters has high control accuracy and good performance, but the inverter system is expensive; The second and third control accuracy and performance are average, but the inverter system is simple and cheap.

1. The inverter belongs to the category of "stationary converter" in the value-added tax, and the tax classification code of the inverter is 109040403.

2. Selection and retrieval of tax classification codes.

1) In the process of invoicing with the golden tax disk, select the "tax classification code" in the corresponding "business brand code add" interface.

2) Click to enter the "Tax Classification Code" list. Enter the product name keyword in the Index box, and the system will automatically search for the tax classification code and product name corresponding to the keyword.

Note: In the "Tax Classification Code" window, if you can't find a matching product name, you can select a similar product name. For example, in "real estate operating lease", "other immovable refers to full-time operating lease services".

3) For small-scale enterprises, if you want to issue an invoice with a tax rate of 3%. For example, small-scale enterprises in the hotel industry will issue accommodation fees at a rate of 3%. Select "Other Life Services" in the tax classification code, and the default tax rate is 6%.

After double-clicking to select, you need to modify the tax rate that actually applies to you. Finally, the "tax rate" of this accommodation fee is 3% on the screen where the invoice is issued.

Legal basis

Law of the People's Republic of China on the Administration of Tax Collection

Article 1 This Law is enacted for the purpose of strengthening the administration of tax collection, standardizing the collection and payment of taxes, safeguarding state tax revenues, protecting the legitimate rights and interests of taxpayers, and promoting economic and social development.

Article 2 This Law shall apply to the collection and administration of the taxes collected by the tax authorities in accordance with the law.

Article 3 The initiation and suspension of taxation, as well as tax reduction, exemption, tax refund, and tax compensation, shall be implemented in accordance with the provisions of the law and the provisions of the administrative regulations formulated by the law.

No organ, unit, or individual may violate the provisions of laws and administrative regulations by making decisions on tax collection, suspending, tax reduction, tax exemption, tax refund, tax compensation, or other decisions that contradict tax laws and administrative regulations.

Article 4 Units and individuals that are liable to pay taxes as stipulated by laws and administrative regulations are taxpayers.

Units and individuals that are required by laws and administrative regulations to withhold and remit, collect and remit taxes are withholding agents. Taxpayers and withholding agents must pay, withhold, collect and remit taxes in accordance with the provisions of laws and administrative regulations.

The inverter is mainly composed of rectifier (AC to DC), filtering, inverter (DC to AC), braking unit, drive unit, detection unit, microprocessor unit, etc. By changing the frequency of the power supply to achieve the purpose of changing the power supply voltage, according to the actual needs of the motor to provide the required power supply voltage, so as to achieve the purpose of energy saving, speed regulation, in addition, the inverter has a lot of protection functions, such as overcurrent, overvoltage, overload protection and so on. With the continuous improvement of industrial automation, frequency converters have also been widely used.

Inverter models are different due to different manufacturers, such as our company's most advanced inverter has Shanyu and Alpha, Shanyu inverter model is SY8000 series, Alpha inverter model is alpha6000 series, conventional inverter is divided into general type and fan pump inverter, these two are more common, of course, there are other mechanical equipment special inverter. I hope my answer helps! As a frequency converter peer, we encourage each other, help each other and cooperate for common development.

Good luck with your business!