Article by: Artery Technology Co.
Along with the developments of MCU and modern control technology, the VFD is becoming smaller and lighter, and moving towards high-performance, high-function and environmentally friendly development.
Growing requirements for industrial automation and energy saving continue to promote the development of Variable Frequency Drive (VFD) and its widespread applications in electric power, cement, elevator, mining industries. , metallurgy, transport and others. In recent years, the VFD market has grown rapidly. In recent years, in particular, the VFD market has maintained an annual growth rate of 12% to 15%, which is expected to continue to grow at a rate of more than 10% within five years.
As a power control device, the VFD is used to control the alternating current (AC) motor by changing the operating frequency of the motor using frequency conversion technology and microelectronic technology.
During the operation of the VFD, the MCU, as an essential component of the VFD system, provides the required power supply for the motor. Along with the development of high-performance microprocessors and modern control technology, the frequency converter is becoming smaller and lighter, and moving towards high-performance, high-function and environmentally friendly development.
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Variable Frequency Vector Drive (VVFD) and Variable Frequency Drive (VFD)
In general, the frequency converter contains a general-purpose frequency converter and a vector frequency converter. The VVFD is similar to the DC motor in terms of control logic. It uses vector control technology and is based on the dynamic mathematical model of rotor flux-oriented control which is commonly used in the induction motor field.
For work machines like industrial robots with fast response requirements, the drive system should be responsive to a speed of at least 100 rad/s. As the VVFD can go up to 1000 rad/s, it is able to allow the robot drive system to operate quickly and accurately. For this reason, VVFD is often used in the heavy starting scenario such as conveyor belts and high horsepower hoists. But this is not the case for the common frequency converter. The heavy load and insufficient torque induced when starting would prevent the motor from starting, resulting in a stuck error or overcurrent.
ARTERY AT32 MCU VFD Application
Vector frequency control provides large and stable output torque, low noise and high efficiency. However, it deals with a complex algorithm and a large amount of calculations, thus putting forward higher requirements for the performance of MCUs. In this regard, the AT32F421 series of the ARTERY value line based on the ARM® Cortex®-M4 core offers a cost-effective solution to the VVFD application. The AT32F421 series operates at a frequency of up to 120 MHz and integrates up to 64 KB of Flash memory and 16 KB of SRAM, with rich interfaces and many features, thus guaranteeing high performance and precision of the control system. of the motor drive. And finally, its price is almost close to the price of M0 powered MCU even though it is powered by M4 core.
The core part of the VVFD system is the AT32F421C8T7 MCU, which controls the IGBT and current sensor in VVFD for power saving, speed regulation, and VVFD protection against overcurrent, overvoltage, and overload. The AT32F421 series features fast GPIO response and up to 2MHz ADC conversion rate, ensuring high-speed VVFD response, precise torque control, flexible speed adjustment, and good throttle control and of deceleration. All this makes it particularly suitable for applications with high torque control requirements.
On the other hand, the VVFD must maintain stability in the industrial environment challenged by electromagnetic waves, corrosion gases and vibrations, etc. The AT32F421 series operates in the temperature range of -40 to 105°C and is therefore able to withstand the harsh environment, for example, paper machines, printing and dyeing machines need to operate in very harsh environments. humid and at high temperature with corrosive gases.
Advantages of AT32F421C8T7 applications
- Cortex-M4 core, cost-effective, maximum frequency up to 120MHz, fast computing power
- Rich peripheral interfaces, flexible data acquisition, support for interconnecting with multiple terminals
- Fast GPIO response and ADC conversion rate up to 2 MHz
- Capable of working in the wider temperature range of -40 to 105°C
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