[分享]電子變速的頻率用處

[原文由版友老人家張貼]

電變頻率對玩車的影响 : 頻率越高越能發揮電池的能量 , 而且可以回差電流入電池 , 加長行車時間
那麼什麼是回差呢 ? 當電變未到極速點時用迫力 , 摩打產生的能量便會回流入電池 , 但電變上的Mosfet開關動作必要以極快速率進行 , 所以頻率越高越有好的回差
高頻率對摩打還可以在短時間以最快的速率把脈沖電流輸入摩打 , 這便可大大減小碳刷與銅頭磨擦產生的火花 , 延長摩打壽命

[原文由版友shungyan張貼]

IMO. It is hard to say higher operating frequency is equal to better.

An extensive debate is still going on how the frequency affect the ESC's performance. Too high or too low is also not good. Both high and low frequency will have its own advantage and drawback. Not going into too detail but they have the following affect on the ESC.

Higher frequence
Advantage
- Higher top speed
- Higher throttle resolution
- Can re-charge the battery when non-full throttle (Depends on individual brand. The one require Diode on the motor has less ability on this espect)
- Lower wear on the motor

Disadvantage
- Too high operating frequence will lead to frequence jam. eg. GT7
- Heat will be generated because of fet ripple (happen at the very first moment when "On" cycle start). Hence efficient drop.
- Electronic noise is higher

Low freqency
advantage
- Have more time to allow current actually flow through the motor, higher torque will be resolution
- Less chance to have frequency jam
- Less chance for Fet ripple. Efficiency is more steady.

Disadvantage
- Lower throttle resolution
- Less run time
- more motor wear


In conclusion, a optimal point must be detected corresponding to the hardware and software the ESC use. But in general if compare a 2000hz ESC with a conventional 50hz ESC. Higher will be better. But if talking about 20k must better than 2k, then it should consider more other factors!