This article introduces three methods that can speed up the design of BLDC motor systems while also providing smarter and more compact energy-saving solutions.
The world is working hard to reduce power consumption, and the momentum is getting stronger and stronger. Many countries/regions require household appliances (as shown in Figure 1) to meet the efficiency standards set by relevant organizations such as the China National Institute of Standardization (CNIS), the US Energy Star, and the German Blue Angels.
In order to meet these standards, more and more system designers have abandoned simple and easy-to-use single-phase AC induction motors in their designs, and instead use more energy-efficient low-voltage brushless DC (BLDC) motors. In order to achieve longer service life and lower operating noise, designers of small household appliances such as sweeping robots have also turned to more advanced BLDC motors in many of their systems. At the same time, the progress of permanent magnet technology is continuously simplifying the manufacture of BLDC motors, reducing the system size while providing the same torque (load), which can also improve efficiency and reduce system noise.
Figure 1: Common household appliances
Designing a system using BLDC motors is challenging because complex hardware and optimized software design are usually required to provide reliable real-time control. One option to speed up the design cycle is to use BLDC motor modules provided by professional suppliers, but these modules are not optimized for the needs of a specific system.
Therefore, in order to build an optimized high-performance system to meet specific application requirements, it is still necessary to have an in-depth understanding of motor design and control, even when using modules. In this article, I will introduce three methods that can speed up the design of BLDC motor systems while also providing smarter and more compact energy-saving solutions.
Method 1: No need to program sensorless control
The motor driver without programming includes a built-in control commutation algorithm, so there is no need for motor control software development, maintenance and certification. These motor drivers usually obtain feedback from the motor (such as Hall signals or motor phase voltage and current signals), calculate complex control equations in real time to determine the next motor drive state, and are gate drivers or metal oxide Semiconductor field effect transistors ( mosfet) and other analog front-end components provide pulse width modulation signals (as shown in Figure 2).
Figure 2: Typical sensorless BLDC motor system
When using a motor driver with integrated sensorless control function (such as the MCF8316A motor driver with Field Oriented Control (FOC) function) for real-time control, there is no need for a Hall-effect sensor in the motor, which can improve system reliability and reduce total system cost. The motor driver without programming can also manage important functions (such as motor fault detection) and implement protection mechanisms to make the overall system design more reliable.
These devices can be accompanied by pre-certified control algorithms implemented by certification agencies such as Underwriters Laboratories, enabling original equipment manufacturers to shorten the design time of their home appliances.
Method 2: Use the intelligent motor control function to easily tune the motor
System performance parameter requirements (such as speed, efficiency, and noise) are difficult to solve by tuning the 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, so that the adjustment operation is not limited by the motor parameters.
The integrated motor driver (such as MCT8316A) that integrates the sensorless trapezoidal control function can provide optimized system performance without the need to use a complicated interface to connect to the microcontroller. In addition, please note that during the motor tuning process, the integrated motor driver will provide feedback signals, such as the motor phase voltage, current, and motor speed displayed on the oscilloscope.
In the sensorless FOC algorithm, due to the integration of advanced control technology, the motor tuning can be significantly accelerated, for example, by measuring the motor parameters by itself or automatically performing the tuning of the control loop.
The guided tuning graphical user interface (GUI) provides default motor startup options (as shown in Figure 3), which helps to smoothly complete the tuning process and spin the motor as quickly as possible. Motor drivers that do not require programming (such as MCF8316A for FOC and MCT8316A for trapezoidal control) include multiple configurable options for motor start and closed loop and motor stop operations. With these options, the motor performance can be optimized within a few minutes, significantly shortening the design cycle.
Figure 3: Guided tuning GUI
Method 3: Reduce the size
For many system designers, the BLDC system hardware construction work is very difficult. 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 drive combines all these components to provide a compact but easy-to-use solution, as shown in Figure 4.
Figure 4: Fully integrated BLDC motor solution
Motor drivers with integrated control functions include protection functions, such as overcurrent and overvoltage protection for MOSFETs, and temperature monitoring, allowing designers to easily provide powerful solutions.
For motor applications with power consumption less than 70W, such as sweeping robots, household ceiling fans, or pumps used in washing machines, devices with integrated MOSFETs can be selected to further reduce the layout 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 to integrate the gate driver and motor control functions into a single chip.
The concepts discussed in this article help to speed up the system design cycle while providing a smaller and smarter BLDC motor system. With the help of MCF8316A and MCT8316A, which do not require programming and sensorless BLDC motor drivers, an optimized high-performance real-time control system can be quickly designed. These devices can provide up to 70W of power for 24V applications. With integrated intelligent control technology, these two motor drives are easy to tune and can be used to achieve high-performance and reliable system solutions. They are ideal for building the next low-voltage energy-saving system based on BLDC.
This article introduces three methods that can speed up the design of BLDC motor systems while also providing smarter and more compact energy-saving solutions.
The world is working hard to reduce power consumption, and the momentum is getting stronger and stronger. Many countries/regions require household appliances (as shown in Figure 1) to meet the efficiency standards set by relevant organizations such as the China National Institute of Standardization (CNIS), the US Energy Star, and the German Blue Angels.
In order to meet these standards, more and more system designers have abandoned simple and easy-to-use single-phase AC induction motors in their designs, and instead use more energy-efficient low-voltage brushless DC (BLDC) motors. In order to achieve longer service life and lower operating noise, designers of small household appliances such as sweeping robots have also turned to more advanced BLDC motors in many of their systems.
At the same time, the progress of permanent magnet technology is continuously simplifying the manufacture of BLDC motors, reducing the system size while providing the same torque (load), which can also improve efficiency and reduce system noise.
Figure 1: Common household appliances
Designing a system using BLDC motors is challenging because complex hardware and optimized software design are usually required to provide reliable real-time control. One option to speed up the design cycle is to use BLDC motor modules provided by professional suppliers, but these modules are not optimized for the needs of a specific system. Therefore, in order to build an optimized high-performance system to meet specific application requirements, it is still necessary to have an in-depth understanding of motor design and control, even with modules. In this article, I will introduce three methods that can speed up the design of BLDC motor systems while also providing smarter and more compact energy-saving solutions.
Method 1: No need to program sensorless control
The motor driver without programming includes a built-in control commutation algorithm, so there is no need for motor control software development, maintenance and certification. These motor drivers usually obtain feedback from the motor (such as Hall signals or motor phase voltage and current signals), calculate complex control equations in real time to determine the next motor drive state, and are gate drivers or metal oxide semiconductor field effect transistors ( MOSFET) and other analog front-end components provide pulse width modulation signals (as shown in Figure 2).
Figure 2: Typical sensorless BLDC motor system
When using a motor driver with integrated sensorless control function (such as the MCF8316A motor driver with Field Oriented Control (FOC) function) for real-time control, there is no need for a Hall-effect sensor in the motor, which can improve system reliability and reduce total system cost.
The motor driver without programming can also manage important functions (such as motor fault detection) and implement protection mechanisms to make the overall system design more reliable. These devices can be accompanied by pre-certified control algorithms implemented by certification agencies such as Underwriters Laboratories, enabling original equipment manufacturers to shorten the design time of their home appliances.
Method 2: Use the intelligent motor control function to easily tune the motor
System performance parameter requirements (such as speed, efficiency, and noise) are difficult to solve by tuning the 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, so that the adjustment operation is not limited by the motor parameters.
The integrated motor driver (such as MCT8316A) that integrates the sensorless trapezoidal control function can provide optimized system performance without the need to use a complicated interface to connect to the microcontroller. In addition, please note that during the motor tuning process, the integrated motor driver will provide feedback signals, such as the motor phase voltage, current, and motor speed displayed on the oscilloscope.
In the sensorless FOC algorithm, due to the integration of advanced control technology, the motor tuning can be significantly accelerated, for example, by measuring the motor parameters by itself or automatically performing the tuning of the control loop.
The guided tuning graphical user interface (GUI) provides default motor startup options (as shown in Figure 3), which helps to smoothly complete the tuning process and spin the motor as quickly as possible. Motor drivers that do not require programming (such as MCF8316A for FOC and MCT8316A for trapezoidal control) include multiple configurable options for motor start and closed loop and motor stop operations. With these options, the motor performance can be optimized within a few minutes, significantly shortening the design cycle.
Figure 3: Guided tuning GUI
Method 3: Reduce the size
For many system designers, the BLDC system hardware construction work is very difficult. 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 drive combines all these components to provide a compact but easy-to-use solution, as shown in Figure 4.
Figure 4: Fully integrated BLDC motor solution
Motor drivers with integrated control functions include protection functions, such as overcurrent and overvoltage protection for MOSFETs, and temperature monitoring, allowing designers to easily provide powerful solutions. For motor applications with power consumption less than 70W, such as sweeping robots, household ceiling fans, or pumps used in washing machines, devices with integrated MOSFETs can be selected to further reduce the layout 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 to integrate the gate driver and motor control functions into a single chip.
The concepts discussed in this article help to speed up the system design cycle while providing a smaller and smarter BLDC motor system. With the help of MCF8316A and MCT8316A, which do not require programming and sensorless BLDC motor drivers, an optimized high-performance real-time control system can be quickly designed. These devices can provide up to 70W of power for 24V applications. With integrated intelligent control technology, these two motor drives are easy to tune and can be used to achieve high-performance and reliable system solutions. They are ideal for building the next low-voltage energy-saving system based on BLDC.