Issue link: https://resources.mouser.com/i/1442844
29 Qorvo 2021 Solution Qorvo and the design group began the project from an understanding that the end product would be a high- performance vacuum. For that reason, they chose a three- phase PMSM because of its use of sinewave commutation, which helps maximize performance. The design relied on FOC and used an algorithm for controlling the stator's revolving magnetic field, relying on two orthogonal components to regulate the magnetic flux generator and determine the available torque. The FOC and the custom algorithm developed by Qorvo enabled precise control over motor speed and made it possible to maximize the overall efficiency of the vacuum. The collaborative work between the design group and Qorvo over several months resulted in a product that successfully fulfilled the product requirements. As a result of this cooperative design effort, this powerful, efficient cordless vacuum cleaner is now available commercially. Overview–Vacuum Cleaner Operation Handheld vacuums generate suction by spinning a motor- driven fan that pulls air through the vacuum's head and— after trapping the ingested dust and debris in a bag or canister—expels it through an exhaust port. Typically, a filter placed in the exhaust stream prevents tiny particles from being discharged. The speed of the fan motor and the dimensions of the intake port (or accessory attachments) determine the degree of suction, ascertained by the negative pressure created when the air is drawn through the head and forcefully discharged from the exhaust. Fan speeds up to 100,000 revolutions per minute, and above are commonly reached in high-end vacuums, such as the product design to which Qorvo contributed. Key Components of a High-Power Vacuum Modern handheld vacuum cleaners incorporate brushless DC (BLDC) motors to achieve maximum performance, generating a rotating magnetic field within the motor enclosure. In this type of brushless design, the stator is stationary, with fixed coils, and permanent magnets are affixed to the rotor, which spins in response to the cycling magnetic fields. The stator coils are controlled by an external electronic motor controller, allowing variable rotational speeds to be produced. Advantages of the BLDC design, which is more complex but much more controllable than brushed DC and traditional induction motors, include highly efficient operation, a more compact footprint, greater reliability, and exceptional long- term durability. The type of BLDC motor selected for this project was a three- phase PMSM, driven by a sinusoidal wave, representing the best choice for meeting the high-performance requirements. The criteria for the project included: Ultra-high-speed motor capabilities Constant power control with over-voltage protection Quick start-up operation Cost-effective design components The design features that enabled Qorvo and the team to satisfy these criteria are discussed in the following section. Today's motor designs have advanced to Brushless DC style.