Get Sensored 3-phase Bldc Motor Control Using Msp430. Application Reports

In a BLDC motor, rotor magnets generate the rotor's magnetic flux, so BLDC motors achieve higher efficiency. Therefore, BLDC motors may be used in high-end white goods (refrigerators, washing machines, dishwashers, etc.), high-end pumps, fans and in other appliances which require high reliability and efficiency.

A sensored BLDC motor is a brushless DC motor with inbuilt positional sensors (called hall effect sensors). These sensors can be used by a brushless motor controller (brushless ESC) to monitor the exact position of the rotor and are therefore a useful method of maintaining speed of the brushless motor.

BLDC motors use electronic instead of mechanical commutation to control the. power distribution to the motor. Latching Hall-effect sensors, mounted in the motor, are used to measure the motor's position, which is communicated to the electronic controller to spin the motor at the right time and right orientation.

How Hall Effect Sensor Works in a BLDC Motor. Typically, a BLDC motor will have three Hall Effect Sensors fitted on the rotor or the stator. These Hall sensors are placed 120 degree apart from each other, giving 0 to 360 degree angle position.

2D and 3D designs are studied and performed in computer research laboratory using ANSYS software. Result data along with waveforms are recorded to calculate efficiency of BLDC motor.

The position sensor plays a role in determining the position of the rotor pole in the BLDC motor, and provides correct phase change information for the logic switch circuit. It converts the position signal of the rotor magnetic steel pole into an electrical signal, and then controls the stator winding phase change.

Using magnetic fields, Hall effect sensors are used to detect variables such as the proximity, speed, or displacement of a mechanical system. Hall effect sensors are non-contact, which means that they do not have to come in contact with a physical element.

Bipolar Hall-effect sensors are used in BLDC motors to detect the position of the rotating magnet. In this example, an eight-pole motor with a three-phase winding uses three bipolar latching Hall-effect sensors. A magnetic field is required to activate a Hall-effect sensor.