新闻资讯
NEWS
/
/
/
What are the classifications of frequency converters?
Check category

What are the classifications of frequency converters?

  • Categories:Industry news
  • Author:
  • Origin:
  • Time of issue:2020-08-06
  • Views:0

What are the classifications of frequency converters?

Frequency conversion speed regulation technology is an important development direction of modern electric drive technology, and as the core of the frequency conversion speed regulation system-the performance of the frequency converter has increasingly become the determinant of the performance of the speed regulation.

Classification of frequency converters

1. According to the nature of DC power supply:

a. Current-type inverter. The characteristic of the current-type inverter is that the intermediate DC link uses a large inductance as the energy storage link to buffer reactive power, that is, to control the change of current and make the voltage close to a sine wave. Because the DC internal resistance is relatively large, It is called current source type inverter (current type). The characteristic (advantage) of the current type inverter is that it can restrain the frequent and sharp changes of the load current. Often selected for occasions where the load current changes greatly;

b. Voltage-type inverter. The characteristic of the voltage-type inverter is that the energy storage element of the intermediate DC link adopts a large capacitor, and the reactive power of the load will be buffered by it. The DC voltage is relatively stable, and the internal resistance of the DC power supply is small, which is equivalent to a voltage source. Therefore, it is called a voltage-type inverter, which is often selected for occasions where the load voltage changes greatly.

2. Classified according to the working mode of the main circuit:

a. Voltage type frequency converter. In the voltage type frequency converter, the rectifier circuit or the chopper circuit generates the DC voltage required by the inverter circuit, which is smoothed by the capacitor of the DC intermediate circuit and then output; the rectifier circuit and the DC intermediate circuit act as a DC voltage source. The DC voltage output by the voltage source is converted into an AC voltage with the required frequency in the inverter circuit;

b. Current type inverter. In a current-type frequency converter, the rectifier circuit gives out a direct current, and the current is smoothed out after being smoothed by the reactance of the intermediate circuit. The rectifier circuit and the DC intermediate circuit function as a current source, and the DC current output by the current source is converted into an AC current with a desired frequency in the inverter circuit, and is distributed to each output phase and then supplied to the motor as an AC current.

3. According to the switch force type classification:

a. PAM control. PAM control is the abbreviation of PulseAmplitudeModulation (pulse amplitude modulation) control. It is a control method in which the amplitude of the output voltage (current) is controlled in the rectifier circuit part, and the output frequency is controlled in the inverter circuit part;

b. PWM control. PWM control is the abbreviation of PulseAmplitudeModulation (pulse width modulation) control. It is a control method that simultaneously controls the amplitude and frequency of the output voltage (current) in the inverter circuit part;

c. High carrier frequency PWM control. In principle, this control method is actually an improvement of the PWM control method, and is a control method adopted to reduce the running noise of the motor. In this control mode, the carrier frequency is increased above the frequency (10-20kHz) that can be heard by human ears, so as to achieve the purpose of reducing motor noise.

4. Classified according to the link of transformation:

a. It can be divided into AC-AC inverter. Directly transform the power frequency AC into AC with adjustable frequency and voltage, also known as direct inverter;

b. AC-DC-AC inverter. It first converts the power frequency AC into DC through a rectifier, and then converts the DC into AC with adjustable frequency and voltage. It is also called an indirect frequency converter and is a universal frequency converter widely used at present.

Relevant information

Application

Application of IPC-PUS Pumping Unit Intelligent Control Cabinet in Huoshaoshan Oilfield, Xinjiang

This paper mainly presents the application of IPC PUS to Beam Pumper of HuoShaoShan,The core controller of IPC-PUS series control system use pumping unit dedicated control program and digital feedback technology and it can automatically run by setting in advance. The whole system has a bypass function ,its control scheme reliable performance and simple operation and high efficiency for energy- saving.Taking HuoShaoShan oil field as an example,this paper analyzes its application and provides IPC-PUS series control system in the pumping unit system optimal application promotion scheme.
2018-03-13
Hailiang

Hailiang Group Project

Inner Mongolia Hailiang Real Estate Development Co., Ltd. is a wholly-owned subsidiary of Hailiang Group. At present, it has invested more than 4 billion yuan in Hohhot to build Hailiang Plaza, a landmark project in Hohhot. Hailiang Real Estate will rely on Hailiang Plaza, Buildings A, B, C, and D of Hailiang Plaza are business office apartment buildings that integrate office and accommodation. Each of them has 6 elevators under the Guangzhou Hitachi brand. The floor is 35 floors, the elevator power is 30KW, and the elevator speed is 2.0m/s.
2018-05-17
Application

Application of PSG energy feedback device in mine hoist

Most of the coal mine hoists use a resistor in the stator coil of the motor to achieve the effect of speed regulation. During operation, part of the energy is released to the resistor by releasing electrical energy, thereby reducing the speed of the motor, which is bound to cause some electrical energy. Loss and waste. In addition, the resistance heating increases the indoor temperature. As the motor runs for a long time, the motor shell becomes severely heated and needs to be shut down for cooling, which greatly reduces the life of the motor and also affects the production efficiency. The society is progressing and technology is developing. This confusion has aroused the attention of equipment users. The installation of energy feedback has been widely used. Of course, energy feedback should replace the backward control method of resistance heating.
2018-03-14
Application

Application of PSG feedback unit on dynamometer

The dynamometer is also called the motor type test system in the motor testing industry, which mainly tests the load characteristics of the motor. The dynamometer is a load machine that applies a variable torque load to the motor under test and absorbs its power. Equipped with a display control system, it can test various types of motors (such as: single three-phase asynchronous motors, synchronous motors, DC motors, series The input voltage, current, power and output torque, speed, power and characteristic curve of excitation motor, power tool, wheel hub motor, starter motor, automobile motor, etc.). According to the working principle, it is mainly divided into hysteresis dynamometer, magnetic particle dynamometer, electric turbine dynamometer, and electric dynamometer.
2018-04-16
Previous page
1
2
3

3rd Floor, Building 2A, Meibaohe Industrial Park, No.14 Shilongzai Road, Dalang Community, Longhua New District, Shenzhen

86-755-83409720 86-755-82839926

86-755-82839967

这是描述信息

Follow IPC

这是描述信息

Copyright 2021. Shenzhen IPC Technology Co., Ltd. All rights reserved.   Power by:300.cn   Shenzhen   粤ICP备13061212号  SEOnavigation