Brushless.com's 72V Brushless DC (BLDC) motors are an advanced motor technology used in a wide range of applications such as electric transportation, automation equipment, renewable energy systems, and high-efficiency industrial drives. Compared to lower voltage BLDC motors, 72V motors are able to provide higher power densities, higher load capacities, and higher energy efficiency for scenarios where high performance is required.One of the key features of BLDC motors is that they rely on precise electronic control for brushless commutation. Traditionally, this precise control has relied on sensors, such as Hall sensors mounted inside the motor, to detect the precise position of the rotor in real time. However, with advances in technology, sensor control is not the only option, and sensor control systems can be used in other ways to achieve the same level of precision. Brushless.com uses sensorless control technology extensively in its 72V BLDC motors, which is based on the motor's voltage and current information, and is able to reduce costs and simplify the design, while increasing the reliability and durability of the system. system reliability and durability while reducing cost and simplifying design.
In Brushless.com's 72V BLDC motors, the trapezoidal commutation method is commonly used, which is an efficient and cost-effective commutation method, especially for high RPM applications and scenarios that require high starting torque. The advantages of trapezoidal commutation are the simplicity of the algorithm, ease of implementation, and the ability to replace the Hall sensor with the motor's Back EMF for sensorless control. Usually, during the operation of a three-phase BLDC motor, one phase winding is positive, one phase is negative, and the third phase is idle. The zero-crossing point of the rotor can be determined by detecting the reverse electromotive force in the idle winding, and the change in this signal corresponds to the information provided by the Hall sensor. However, the amplitude of the counter electromotive force is proportional to the speed of the motor, which means that at start-up the counter electromotive force is almost zero due to the low speed and does not provide sufficient commutation information. Therefore, at motor startup, the system must first operate in open-loop mode until the motor reaches a sufficient speed before switching to closed-loop control based on the inverse electromotive force.Brushless.com's 72V BLDC motors are able to maintain smooth operation at startup while ensuring control accuracy through this approach.
In Brushless.com's 72V BLDC motors, Zero Crossing Detection is a key technique used to accurately time motor commutation events. Zero Crossing Detection is accomplished by identifying the intersection of the reverse electromotive force waveform with the zero voltage level, information that is critical to the accuracy and efficient operation of the motor's phase transition. Zero-crossing detection can be implemented either in hardware or in software. In a hardware scheme, a comparator circuit is typically used to compare the input signal to the zero level, generating a square wave signal to indicate the timing of the commutation. This hardware scheme provides zero-crossing information in real time, which enables fast response. In a software solution, the system samples the input signal, determines the zero-crossing point through signal processing algorithms, and generates the corresponding control signals. Brushless.com's 72V BLDC motors extensively use software-implemented zero-crossing detection, which not only simplifies the hardware design, but also improves the motor's commutation precision and operation efficiency. Because of this, 72V BLDC motors can maintain high efficiency and stable performance at high speeds and under complex loads.
The application of sensorless control technology in Brushless.com's 72V BLDC motors provides significant support for reducing system complexity and improving cost-effectiveness. Sensorless control is based on real-time monitoring of voltage and current at the motor terminals, and advanced algorithms to derive the actual position of the rotor. This approach eliminates the need for external position sensors, reduces manufacturing costs and simplifies system design. Sensorless control technology offers more than just economic advantages; it also significantly improves motor reliability because there is no risk of mechanical wear or failure of sensors, reducing downtime due to sensor damage or failure. In addition, the elimination of sensors and associated wiring also allows for a more compact design, simplifying the installation process. This approach is particularly suitable for application scenarios that require high environmental adaptability, such as in environments with high levels of dust, humidity, vibration, or magnetic field interference, where Brushless.com's 72V BLDC motors can maintain stable operation over long periods of time, unaffected by damage to the physical sensors.