Difference between revisions of "Empulse Motor Efficiency"

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(Created page to explain the optimal RPM based on mode.)
 
(Updated based on new information from Brian Wissman.)
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The Empulse's electric motor has peak efficiency and peak power at about the same RPM. Operating the motor at peak efficiency gives the best range for a given speed. In order to get the most range, the motor should be kept as close to the optimal RPM as possible, selecting the gear that achieves that.  
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The peak '''efficiency''' on of the Empulse's electric motor depends on the RPM. The peak '''power''' depends on two factors; the mode and the RPM.  
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{| border="1" cellspacing="0" cellpadding="3"
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! Mode
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! Peak Efficiency
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! Peak Power
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|-
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| Sport
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| 5,000 RMP
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| 5,000 RMP
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|-
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| Normal
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| 5,000 RMP
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| 7,000 RMP
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|-
 +
|}
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== Efficiency ==
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In order to get the most '''range''' at a given speed, the motor should be run at it's peak '''efficiency''' RPM, which is '''5,000 RPM'''. Note that vehicle speed is the most important factor when determining energy consumption, so going slower will usually provide more range. However, for a given speed, selecting a gear to keep the motor at 5,000 RPM will give the most range.
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== Power ==
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When the motor is operating at peak '''power''', the bike will be able to '''accelerate fastest'''. Peak power depends on the mode and the RPM.
  
The Empulse has two modes of operation, and the RPM value for peak efficiency depends on the mode.
 
 
;Sport Mode
 
;Sport Mode
:5000 RPM
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:5,000 RPM
 
;Normal Mode
 
;Normal Mode
:7000 RPM
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:7,000 RPM
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That means that acceleration as fast as possible in Sport Mode, the gear change should happen soon after 5,000 RPM, while in Normal mode, the gear change should happen closer to 7,000 RPM.
  
That means that when operating in Sport Mode, the bike will get the most range if the motor kept near 5000 RPM, while in Normal Mode, the most range will be achieved near 7000 RPM.
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''Notes:''
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* During the break in period, the motor should not be operated at more than 6,000 RPM. <sub>(This needs to be verified)</sub>
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* In Normal mode, the shift light will start lighting up at 6,000 RPM, so when running in Normal Mode at peak power, expect the shift light to be lit.
  
Note that the shift light will start to light up at 6000 RPM, so when running in Normal Mode at peak efficiency, expect the shift light to be lit.
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== References ==
  
 
<blockquote>
 
<blockquote>
----
 
 
'''Brian Wissman:'''
 
'''Brian Wissman:'''
  
''You should see the shift lights on the dash progressively light up from left to right after you pass about 6,000 rpm.''
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''You should see the shift lights on the dash progressively light up from left to right after you pass about 6,000 rpm.''<sup>1</sup>
  
''One of our Systems Engineers pointed something out to me recently that I probably have not presented well in the past - 5k is a good target rpm for "Sport" mode, but "Normal" mode moves peak power out closer to 7k rpm, so it is actually beneficial (for performance and range) to ride at higher rpm in normal modeThe slightly reduced torque will also make gear selection more critical.''
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''You should target about 5,000 rpm in either Normal or Sport modes for peak efficiency.  Just know that in Normal mode, you'll need to run to about 7,000 rpm to hit peak power.  In Sport mode, the peak power and peak efficiency coincide at that same 5,000 rpm.  This is simplifying things a bit as the efficiency is also related to the load on the motor, but I think this is a good "rule of thumb" for riding the Empulse effectively.''<sup>2</sup>
 
</blockquote>
 
</blockquote>
  
=== References ===
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* 1 http://brammoforum.com/index.php?topic=1757.msg13646#msg13646
http://brammoforum.com/index.php?topic=1757.msg13646#msg13646
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* 2 http://brammoforum.com/index.php?topic=1757.msg13912#msg13912

Revision as of 19:17, 29 January 2013

The peak efficiency on of the Empulse's electric motor depends on the RPM. The peak power depends on two factors; the mode and the RPM.

Mode Peak Efficiency Peak Power
Sport 5,000 RMP 5,000 RMP
Normal 5,000 RMP 7,000 RMP

Efficiency

In order to get the most range at a given speed, the motor should be run at it's peak efficiency RPM, which is 5,000 RPM. Note that vehicle speed is the most important factor when determining energy consumption, so going slower will usually provide more range. However, for a given speed, selecting a gear to keep the motor at 5,000 RPM will give the most range.

Power

When the motor is operating at peak power, the bike will be able to accelerate fastest. Peak power depends on the mode and the RPM.

Sport Mode
5,000 RPM
Normal Mode
7,000 RPM

That means that acceleration as fast as possible in Sport Mode, the gear change should happen soon after 5,000 RPM, while in Normal mode, the gear change should happen closer to 7,000 RPM.

Notes:

  • During the break in period, the motor should not be operated at more than 6,000 RPM. (This needs to be verified)
  • In Normal mode, the shift light will start lighting up at 6,000 RPM, so when running in Normal Mode at peak power, expect the shift light to be lit.

References

Brian Wissman:

You should see the shift lights on the dash progressively light up from left to right after you pass about 6,000 rpm.1

You should target about 5,000 rpm in either Normal or Sport modes for peak efficiency. Just know that in Normal mode, you'll need to run to about 7,000 rpm to hit peak power. In Sport mode, the peak power and peak efficiency coincide at that same 5,000 rpm. This is simplifying things a bit as the efficiency is also related to the load on the motor, but I think this is a good "rule of thumb" for riding the Empulse effectively.2