Current Development Status and Trends of Inverter

With the continuous improvement of industrial automation, Inverters  have also been widely used. Inverter  (VFD) is a power control device that uses frequency conversion technology and microelectronics technology to control AC motors by changing the frequency of the motor's working power supply. Inverters  are high-tech products with high technological content, high added value, and good returns. They are industrial products that comply with national industrial development policies.

Inverters have a development history of nearly 30 years in China, as a power control equipment that utilizes frequency conversion technology and microelectronics technology to control AC motors. In the past few decades, Inverters  have made certain achievements in industrial scale, application fields, and product functions. The Inverter  industry faces many challenges.

Affected by national macroeconomic regulation, investment in some industries has been directly suppressed, directly affecting various automation products such as Inverter s, PLCs, and HMIs. The large PLC market in China is basically flat with almost no growth, mainly affected by the decrease in regulatory investment in the metallurgical industry. This industry regulation will mainly affect the basic industries of the country, corresponding to low-voltage Inverter s, and mainly affect the project oriented market of their applications, such as metallurgy, power, oil and gas, chemical and other industries.

So what is the current development status of Inverters in China?

A Inverter  is an electrical energy control device that utilizes the on-off effect of power semiconductor devices to convert a power frequency power supply to another frequency. The Inverter  we are currently using mainly adopts the AC-DC-AC mode (VVVF frequency conversion or vector control frequency conversion). Firstly, the power frequency AC power supply is converted into a DC power supply through a rectifier, and then the DC power supply is converted into an AC power supply that can be controlled by both frequency and voltage to supply the electric motor. The circuit of a Inverter  generally consists of four parts: rectification, intermediate DC link, Inverter, and control. The rectifier part is a three-phase bridge uncontrollable rectifier, while the Inverter  part is an IGBT three-phase bridge Inverter  with a PWM waveform output. The intermediate DC link is filtering, DC energy storage, and buffering of reactive power.

AC motor variable Inverter speed regulation has become the trend of contemporary motor speed regulation. Its small size, light weight, large torque, high accuracy, strong functionality, high reliability, easy operation, and easy communication functions are superior to any previous speed regulation method. Therefore, in steel, non-ferrous metals, petroleum, petrochemical, chemical fiber, textile, machinery, power, electronics, building materials, coal, medicine, papermaking, injection molding, cigarette, crane, urban water supply Central air conditioning and sewage treatment industries are widely used. The article introduces the introduction of frequency conversion speed regulation technology in developed countries such as Japan, the United States, and Europe into the Chinese market and the rise of domestic enterprises, and points out that Inverters are developing towards high-performance, modular, specialized, and multifunctional technology. The continuous increase in usage, the continuous decrease in prices, and the merger of industry combinations have the potential to expand overseas. 

AC motor variable frequency speed regulation has become the trend of contemporary motor speed regulation. It has advantages over any previous speed regulation method, such as small size, light weight, large torque, high accuracy, strong functionality, high reliability, easy operation, and easy communication, such as pole change speed regulation, voltage regulation speed regulation, slip speed regulation, cascade speed regulation, commutator motor speed regulation, hydraulic coupling speed regulation, and even DC speed regulation. Therefore, it is widely used in the industries of steel, non-ferrous metals, petroleum, petrochemicals, chemical fibers, textiles, machinery, power, electronics, building materials, coal, medicine, papermaking, injection molding, cigarettes, cranes, urban water supply, central air conditioning, and sewage treatment.

The development of motion control systems is the power converter in motion control systems, and motion control systems are the development of electrical transmission technology as electromechanical energy converters. The current motion control system is a technical field that encompasses multiple disciplines, and the overall development trend is: AC driven, high-frequency power converters, digital, intelligent, and networked control. Therefore, as an important power conversion component of the system, frequency converters have developed rapidly by providing controllable and high-performance variable voltage variable frequency AC power sources.

The Development Trend of Inverters in China

The development trend of Inverter  technology has gone through about thirty years of research and application practice. With the application of new power electronic devices and high-performance microprocessors, as well as the development of control technology, the performance price ratio of frequency converters is getting higher and smaller, while manufacturers are still continuously improving reliability to achieve further miniaturization, lightweight, high-performance, multifunctional, and pollution-free Inverters. The performance of a Inverter  depends on the impact of the harmonics of its output AC voltage on the motor, the harmonic pollution to the power grid and the input power factor, and the energy loss (ie efficiency). Taking the AC-DC-AC Inverter  as an example, it will further develop in the following aspects from a technical perspective:

1. The power switch components of the main circuit are self turned off, modularized, integrated, and intelligent, with increasing switching frequency and further reducing switching losses.

2. In terms of the topology structure of the main circuit of the Inverter : The grid side converter of the Inverter  often uses a 6-pulse converter for low voltage and small capacity, while multiple Inverter s with more than 12 pulses are used for medium voltage and large capacity. The load side converter often uses two-level bridge inverters for low voltage and small capacity, while multi-level inverters are used for medium voltage and large capacity.

3. Control method of pulse width modulation variable voltage Inverter : Sine wave pulse width modulation (SPWM) control. PWM control to eliminate specified harmonics. Current tracking control. Voltage space vector control (flux tracking control).

4.  Progress in variable frequency adjustment control methods for AC motors: from scalar control (V/f control and slip frequency control) to vector control and direct torque control with high dynamic performance. Develop vector control and direct torque control systems without speed sensors.

Our team of experienced professionals is dedicated to delivering personalized services that exceed our customers' expectations. We offer a diverse range of services,including after-sales and maintenance, among others. Our team is composed of experienced engineers and technicians who are highly skilled in the maintenance and troubleshooting of Inverters.

 In conclusion, Rockss Automation Technology Co. Ltd. is the perfect partner for all your automation needs. Whether you need Inverters for industrial, manufacturing, or commercial purposes, we have it all. Our commitment to providing quality products and services at competitive prices, coupled with our experienced team of professionals, is what sets us apart. Contact us today and let us help you streamline your automation needs.