The efficiency of the BLDC motor Tongsheng TSDZ2 and Astro 3205 compared
Published: 28 January 2022
Last updated: 09 March 2023
How good is the brushless DC motor that is being used inside the Tongsheng TSDZ2 ?
To answer this question, I have compared the TSDZ2 motor with one of the highest quality electric motors available: the Astro 3205 from Astro Flight.
This is what’s Astro Flight tells: The goal with the 32XX has been to create a superior quality motor. Starting at the core of the motor, the 32XX uses the highest grade of sintered samarium-cobalt magnet. This is a very high-quality magnet that is rarely found on motors of this price point.
Here are the motor parameters that I have measured, and the corresponding efficiency curves from 0W - 1000W:
Parameters | TSDZ2 | Astro 3205 14T |
k [V/rad/s] | 0.0806 | 0.0442 |
Tf [Nm] | 0.0798 | 0.0385 |
R [Ω] | 0.1875 | 0.1954 |
You can see at the graphs that the TSDZ2 motor is almost as good as the expensive Astro 3205, which cost over $400.
- All losses, also iron losses, are included in Tf.
- The speed difference is just 8000rpm - 4000rpm. Both motors can use 2-stage gear transmissions, so the gear losses are equal.
- The motor resistance of the 8-turn motor is 0.05Ω according to the datasheet. At 14 turns, the resistance should be 0.05Ω (14/8)^2 = 0.153Ω. But I measured 0.195Ω, which is 27% larger.
More information about motor parameters
- https://www.avdweb.nl/solar-bike/hub-motor/measuring-motor-parameters
- https://www.avdweb.nl/solar-bike/hub-motor/hub-motor-simulation
- https://www.avdweb.nl/solar-bike/hub-motor/permanent-magnet-dc-hub-motor-tuning
- https://www.avdweb.nl/solar-bike/hub-motor/get-motor-parameters-from-graph
- https://www.avdweb.nl/solar-bike/hub-motor/cute-q-85sx-motor-test