Electric motor performance in UAVs is a critical part of their design. Weight, operating temperature, and electrical efficiency of the power components influence various parameters such as flight duration, payload, operating ceiling, and range. Electric motors and their design need to account for all the above and more. 

Among others, designers need to determine: 

  • what propeller to use, 
  • what motor to use, 
  • what air motor controller to use, 
  • what voltage to use, 
  • what battery to use, 
  • how peak power differs from continuous power, and 
  • how to use performance curves for the most efficient systems. 

All that and more is dependent on mission parameters because they will not only determine the payload requirements and the overall size of the vehicle, but they will also demand different motors and propellers used at different voltages with compatible air motor controllers.   

As a result, the propulsion system must be configured to support various requirements and answer all the questions above (and more) for best performing motors while considering the fact that minute details of the design can be very complex and have a significant impact on the UAV performance.  

But designers can balance competing demands of their products’ performance needs.  

Main considerations 

Unfortunately, many designers and manufacturers focus on thrust, but simply choosing higher thrust doesn’t mean better efficiency. When designing UAV electric motors, the most important parameter is not higher thrust. Better system thrust efficiency is where designers should focus—more specifically, how many grams of force are required per watt. 

Performance requirements are the second most important parameter. The final design will depend on what’s needed performance-wise. For example, if lower temperatures are required, a smaller propeller may be needed. 

Thirdly, the propeller, motor controller, propulsion motor, and battery need to work together to help efficiency. Their operation is interrelated, and all their separate performances need to be considered and matched.  

Finally (and following on the previous point), every application is unique and requires data analysis. Designers need to know how every part of their motor functions under different conditions and base their decisions on that information. To create the most-efficient and best-performing UAV, clear and comprehensive data is paramount. Using information gathered from testing will enable designers and manufacturers to pick the right materials, voltages, speeds, etc. for their specific mission parameters.  

The final product also needs to support a CAN interface to allow for continuous real-time data monitoring.  

With ePropelled, using data to create the most efficient motors allows UAVs to: 

  • Fly higher—our unique cooling features enable UAVs to fly higher in thinner air.  
  • Fly longer—we offer high thrust efficiency per motor weight compared to other providers. 
  • Fly smarter—feedback from sensors helps to evaluate conditions in real time. 
  • Fly efficiently—our propulsion motor peak efficiencies are up to 97% and intelligent air motor controller efficiencies are up to 99%. 

This blog post is an excerpt from our webinar on the subject of analyzing data and demystifying electric motor performance.