“Designing systems using BLDC motors is challenging because complex hardware and optimized software designs are often required to provide reliable real-time control. One option to speed up the design cycle is to use BLDC motor modules from specialized suppliers, but these modules are not optimized for the needs of a specific system. Therefore, in order to build optimized high-performance systems to meet specific application needs, a deep understanding of motor design and control is still required, even when using modules.
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The global effort to reduce power consumption is gaining momentum. Many countries require home appliances to meet efficiency standards set by relevant organizations such as China National Institute of Standardization (CNIS), Energy Star in the US, and Blue Angel in Germany. To meet these standards, more and more system designers are moving away from simple and easy-to-use single-phase AC induction motors in their designs in favor of more energy-efficient low-voltage brushless DC (BLDC) motors. Designers of small appliances such as robotic vacuums are also turning to more advanced BLDC motors in many of their systems in order to achieve longer life and lower operating noise. At the same time, advances in permanent magnet technology are continuing to simplify the manufacture of BLDC motors, reducing system size while providing the same torque (load), improving efficiency and reducing system noise.
Designing systems using BLDC motors is challenging because complex hardware and optimized software designs are often required to provide reliable real-time control. One option to speed up the design cycle is to use BLDC motor modules from specialized suppliers, but these modules are not optimized for the needs of a specific system. Therefore, in order to build optimized high-performance systems to meet specific application needs, a deep understanding of motor design and control is still required, even when using modules. In this article, I’ll describe three approaches that can speed up BLDC motor system design while also providing a smarter, smaller, energy-efficient solution.
Method 1: Sensorless control without programming
The programming-free motor driver includes built-in control commutation algorithms, eliminating the need for motor control software development, maintenance, and certification. These motor drivers typically take feedback from the motor (such as Hall signals or motor phase voltage and current signals), compute complex control equations in real-time to determine the next motor drive state, and provide feedback for gate drivers or metal-oxide-semiconductor field-effect transistors ( Analog front-end components such as MOSFETs) provide a pulse-width modulated signal (as shown).
Figure: Typical sensorless BLDC motor system
When using a motor driver with integrated sensorless control, such as the MCF8316A motor driver with Field Oriented Control (FOC), for real-time control, no Hall-effect sensors are required in the motor, thereby increasing system reliability and reducing overall system cost. The programming-free motor driver can also manage important functions such as motor fault detection and implement protection mechanisms that make the overall system design more reliable. These devices can be delivered with pre-certified control algorithms implemented by certification bodies such as Underwriters Laboratories, enabling OEMs to shorten the design time of their home appliances.
Method 2: Easily tune the motor with Smart Motor Control
System performance parameter requirements such as speed, efficiency and noise are difficult to address by tuning a BLDC motor. This problem can be solved by developing a sensorless trapezoidal control algorithm in which the commutation is determined by the back-EMF voltage of the motor, making the adjustment operation independent of the motor parameters. An integrated motor driver such as the MCT8316A with integrated sensorless trapezoidal control can provide optimized system performance without the need for a complex interface to a microcontroller. Also, note that during motor tuning, the integrated motor driver provides feedback signals such as motor phase voltage, current and motor speed displayed on the oscilloscope.
In the sensorless FOC algorithm, the integration of advanced control techniques can significantly speed up motor tuning, for example, by measuring motor parameters on its own or by automatically performing tuning of the control loop. The Guided Tuning Graphical User Interface (GUI) provides default motor start-up options (shown), which help to complete the tuning process smoothly and get the motor spinning as quickly as possible. Programming-free motor drivers such as the MCF8316A for FOC and the MCT8316A for trapezoidal control include several configurable options for motor start as well as closed loop and motor stop operation. With these options, motor performance can be optimized in minutes, significantly reducing design cycles.
Figure: Guided Tuning GUI
Method 3: Reduce the size
For many system designers, building BLDC system hardware is laborious. A typical system requires gate drivers, MOSFETs, current sense amplifiers, voltage sense comparators, and analog-to-digital converters. Most systems require a dedicated power architecture (including devices such as low-dropout regulators or DC/DC buck regulators) to power all components on the board. The integrated BLDC driver combines all these components to provide a compact yet easy-to-use solution, as shown.
Figure: Fully integrated BLDC motor solution
Motor drivers with integrated control include protection features such as overcurrent and overvoltage protection for MOSFETs and temperature monitoring, allowing designers to easily provide robust solutions. For motor applications that consume less than 70W, such as robotic vacuum cleaners, household ceiling fans, or pumps used in washing machines, devices with integrated MOSFETs can be selected to further reduce board space. The MCF8316A and MCT8316A devices support up to 8A peak current in 24V applications. For high power applications, power MOSFETs can be placed on the board, allowing gate driver and motor control functions to be integrated into a single chip.
The concepts discussed in this article help speed up the system design cycle while providing a smaller, smarter BLDC motor system. With no programming sensorless BLDC motor drivers such as the MCF8316A and MCT8316A, an optimized, high-performance real-time control system can be quickly designed. These devices can deliver up to 70W for 24V applications. With integrated smart control technology, both motor drives are easy to tune for high performance and reliable system solutions ideal for building the next low voltage energy efficient BLDC based system.
The global effort to reduce power consumption is gaining momentum. Many countries require home appliances to meet efficiency standards set by relevant organizations such as China National Institute of Standardization (CNIS), Energy Star in the US, and Blue Angel in Germany. To meet these standards, more and more system designers are moving away from simple and easy-to-use single-phase AC induction motors in their designs in favor of more energy-efficient low-voltage brushless DC (BLDC) motors. Designers of small appliances such as robotic vacuums are also turning to more advanced BLDC motors in many of their systems in order to achieve longer life and lower operating noise. At the same time, advances in permanent magnet technology are continuing to simplify the manufacture of BLDC motors, reducing system size while providing the same torque (load), improving efficiency and reducing system noise.
Designing systems using BLDC motors is challenging because complex hardware and optimized software designs are often required to provide reliable real-time control. One option to speed up the design cycle is to use BLDC motor modules from specialized suppliers, but these modules are not optimized for the needs of a specific system. Therefore, in order to build optimized high-performance systems to meet specific application needs, a deep understanding of motor design and control is still required, even when using modules. In this article, I’ll describe three approaches that can speed up BLDC motor system design while also providing a smarter, smaller, energy-efficient solution.
Method 1: Sensorless control without programming
The programming-free motor driver includes built-in control commutation algorithms, eliminating the need for motor control software development, maintenance, and certification. These motor drivers typically take feedback from the motor (such as Hall signals or motor phase voltage and current signals), compute complex control equations in real-time to determine the next motor drive state, and provide feedback for gate drivers or metal-oxide-Semiconductor field-effect transistors ( Analog front-end components such as MOSFETs) provide a pulse-width modulated signal (as shown).
Figure: Typical sensorless BLDC motor system
When using a motor driver with integrated sensorless control, such as the MCF8316A motor driver with Field Oriented Control (FOC), for real-time control, no Hall-effect sensors are required in the motor, thereby increasing system reliability and reducing overall system cost. The programming-free motor driver can also manage important functions such as motor fault detection and implement protection mechanisms that make the overall system design more reliable. These devices can be delivered with pre-certified control algorithms implemented by certification bodies such as Underwriters Laboratories, enabling OEMs to shorten the design time of their home appliances.
Method 2: Easily tune the motor with Smart Motor Control
System performance parameter requirements such as speed, efficiency and noise are difficult to address by tuning a BLDC motor. This problem can be solved by developing a sensorless trapezoidal control algorithm in which the commutation is determined by the back-EMF voltage of the motor, making the adjustment operation independent of the motor parameters. An integrated motor driver such as the MCT8316A with integrated sensorless trapezoidal control can provide optimized system performance without the need for a complex interface to a microcontroller. Also, note that during motor tuning, the integrated motor driver provides feedback signals such as motor phase voltage, current and motor speed displayed on the oscilloscope.
In the sensorless FOC algorithm, the integration of advanced control techniques can significantly speed up motor tuning, for example, by measuring motor parameters on its own or by automatically performing tuning of the control loop. The Guided Tuning Graphical User Interface (GUI) provides default motor start-up options (shown), which help to complete the tuning process smoothly and get the motor spinning as quickly as possible. Programming-free motor drivers such as the MCF8316A for FOC and the MCT8316A for trapezoidal control include several configurable options for motor start as well as closed loop and motor stop operation. With these options, motor performance can be optimized in minutes, significantly reducing design cycles.
Figure: Guided Tuning GUI
Method 3: Reduce the size
For many system designers, building BLDC system hardware is laborious. A typical system requires gate drivers, MOSFETs, current sense amplifiers, voltage sense comparators, and analog-to-digital converters. Most systems require a dedicated power architecture (including devices such as low-dropout regulators or DC/DC buck regulators) to power all components on the board. The integrated BLDC driver combines all these components to provide a compact yet easy-to-use solution, as shown.
Figure: Fully integrated BLDC motor solution
Motor drivers with integrated control include protection features such as overcurrent and overvoltage protection for MOSFETs and temperature monitoring, allowing designers to easily provide robust solutions. For motor applications that consume less than 70W, such as robotic vacuum cleaners, household ceiling fans, or pumps used in washing machines, devices with integrated MOSFETs can be selected to further reduce board space. The MCF8316A and MCT8316A devices support up to 8A peak current in 24V applications. For high power applications, power MOSFETs can be placed on the board, allowing gate driver and motor control functions to be integrated into a single chip.
The concepts discussed in this article help speed up the system design cycle while providing a smaller, smarter BLDC motor system. With no programming sensorless BLDC motor drivers such as the MCF8316A and MCT8316A, an optimized, high-performance real-time control system can be quickly designed. These devices can deliver up to 70W for 24V applications. With integrated smart control technology, both motor drives are easy to tune for high performance and reliable system solutions ideal for building the next low voltage energy efficient BLDC based system.
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