How to choose a brushless DC motor driver?

DFRobot Aug 30 2023 3219

Welcome to our series of articles on how to choose a BLDC motor driver. If you want to drive your brushless DC motor, you'll need a good brushless DC motor driver. In this article, we'll provide you with detailed information on the basics of brushless DC motors and drivers, as well as how to select a good one.

1. What is a brushless DC motor?

Let's begin by understanding what a brushless DC motor is. It is a type of motor that uses electromagnetic fields to achieve motion, and the main difference between brushless DC motors and traditional DC motors is that the former has no brushes or commutators, which require periodic replacement. As a result, brushless DC motors have the advantages of simple structure, low noise, and long lifespan, and are increasingly being applied in various industries.

brushless DC motor

Figure：brushless DC motor

2. The applications of brushless DC motors in various industries

In which industries can brushless DC motors be utilized? Brushless DC motors have been widely used in many industries, such as:

Unmanned aerial vehicles: Brushless DC motors are the main power source for UAVs due to their advantages of high power, good aerodynamic stability, and lower noise levels.
Electric vehicles: Similarly, brushless DC motors are also widely used in electric vehicles. Due to their simple structure, low cost, and low maintenance requirements, they have been widely adopted in the EV industry.
Industrial equipment: Brushless DC motors have also been widely used in the industrial field. For example, they can be used in power tools, machine tools, robots, automated production lines, etc. to improve production efficiency and accuracy.
Home appliances: Brushless DC motors are extensively applied in household appliances such as vacuum cleaners, air conditioners, washing machines, electric fans, etc.
Medical equipment: Due to their high precision and fast speed, brushless DC motors are also widely used in medical equipment such as surgical instruments and medical devices.

Brushless DC motors in automated production

Figure: Brushless DC motors in automated production

3. The relationship between brushless DC motors and their drivers

So, what is a brushless DC motor driver? The brushless DC motor driver is a control device used to regulate the movement of a brushless DC motor. It converts the driving signal into an appropriate electrical energy signal that is suitable for controlling the brushless DC motor, and then sends the signal to the motor to make it rotate as required. By using a brushless DC motor driver, we can achieve more precise control of the motor, resulting in higher efficiency and accuracy in its movement.

brushless DC motor driver

Figure：brushless DC motor driver

4. Basic parameters

Having understood the fundamental definition of a brushless DC motor driver, let us now delve into the topic of selecting the appropriate driver. The key aspect of selecting a suitable brushless DC motor driver lies in ensuring that the parameters of both the motor and the driver are compatible. This involves considering two aspects - the parameters of the brushless DC motor and those of the driver itself.

To begin with, it is essential to have a grasp of the fundamental parameters of brushless DC motors:

S/N	Key Parameter	Parameter Description
1	Maximum continuous current	The maximum amount of current that the motor can handle under extreme loads.
2	Rated voltage	The standard voltage set for the motor, usually a stable voltage, which when multiplied by the maximum continuous current gives the required input power.
3	Maximum output power	The maximum amount of power that the motor can output.
4	Number of pole pairs	The number of pole pairs is one of the important parameters that affect the control algorithm of the driver.
5	Encoder availability	Based on whether the motor has an encoder or not, the motor can be classified into two types: a motor with an encoder (sensored motor) and a motor without an encoder (sensorless motor).

Furthermore, it is imperative that we gain a fundamental understanding of the parameters associated with the driver:

S/N	Key Parameter	Parameter Description
1	Maximum Current	The maximum current that the driver can output.
2	Voltage Range	The voltage range in which the driver can operate, which should be differentiated between input and output voltage ranges.
3	Rated Power	The maximum power of the driver, often with a certain amount of redundancy in relation to the maximum power input of the motor.
4	Control Mode	Common control modes include speed loop, current loop (torque loop), and position loop. The control mode is classified into open-loop control and closed-loop control according to whether there is feedback from the encoder involved in the control.
5	Control Algorithm	Common control algorithms include square wave control, sine wave control, and FOC (Field-Oriented Control) vector control, etc.
6	Interface Type	Common control interface types include analog signal, PPM, PWM, UART, CAN, RS485, MODBUS, SBUS, etc.
7	Protection Function	Common protection functions include line sequence abnormality, overcurrent, overload, over temperature, moisture-proof, dust-proof, anti-vibration, etc.

The preceding information outlines the fundamental parameters that we need to consider. When selecting a brushless DC motor driver, it is essential to take into account various factors such as usage requirements, parameter specifications, and cost considerations to achieve optimal performance.

5. Summarize

In this article, we provided a comprehensive introduction to brushless DC motors, brushless DC motor drivers, and the essential parameters to consider when choosing a brushless DC motor driver. By carefully reading and understanding this article, we believe that you have learned the basic methods of how to select a suitable brushless DC motor driver. We hope that this article proves helpful in your decision-making process. It should be noted that this article is part of a series. In our next installment, we will discuss how to choose the best brushless motors and drivers for robotics and automation applications.