VirginiaRick Posted March 31, 2013 Report Share Posted March 31, 2013 'regenerative braking', huh?......So what happens if you go backwards down a slope and apply the brakes? :headscratch: Quote Link to comment Share on other sites More sharing options...
DaveofDurham Posted March 31, 2013 Report Share Posted March 31, 2013 I hope your car would slow down or come to a stop. I think mine would. If you are going backwards at very low speed perhaps you may not see the spinning regenerative brake symbol when you gently apply the brakes because you are going too slow. I think I have noticed this if I am creeping forward. Quote Link to comment Share on other sites More sharing options...
VirginiaRick Posted March 31, 2013 Author Report Share Posted March 31, 2013 I hope your car would slow down or come to a stop. I think mine would. If you are going backwards at very low speed perhaps you may not see the spinning regenerative brake symbol when you gently apply the brakes because you are going too slow. I think I have noticed this if I am creeping forward. I was just thinking of the electrical implications -- if forward motion causes it to act as a generator, then would going in the other direction create a load? Quote Link to comment Share on other sites More sharing options...
DaveofDurham Posted March 31, 2013 Report Share Posted March 31, 2013 I just conducted an experiment with my car on my essentially flat dead end street. Please do not try to replicate this experiment where you live by going downhill in reverse from the crest of the Blue Ridge. First I rolled forward slowly and gently applied the brakes. Even though I was only going around 3mph, the spinning regen symbol lit up when I gently applied the brakes. Next I tried the same thing in reverse and once again the spinning regen symbol lit up when I applied the brakes. I think the answer to your question about "generator" vs "load" is that when the car is being driven by the electric motor the electric motor is turning in the direction that converts electric energy from the battery into mechanical energy to move the car - the direction of electric motor spin is the same regardless of whether you are going forwards or backwards - the direction the car goes (forward or backwards) is determined by the transmission which gets its instructions from where you put the gear selector (forward or reverse). When you gently apply the brakes and reap the benefits of regenerative braking, the electric motor turns in the opposite direction which converts mechanical energy into electrical energy thereby slowing the car and charging the hybrid battery. For more explanation search on "how does regenerative braking work" - you will get more results than you will want to read.One is at http://auto.howstuffworks.com/auto-parts/brakes/brake-types/regenerative-braking1.htmor Ford's description at http://www.myfordmag.com/askford/regenerative-braking (the video doesn't say much except that it is "remarkable") Quote Link to comment Share on other sites More sharing options...
plus 3 golfer Posted March 31, 2013 Report Share Posted March 31, 2013 No, the electric motor and engine turn the same direction whether in reverse or drive. That's why cars have a transmission. So, when the shaft of the motor is supplied power from the engine or from coasting / braking, the electric motor becomes a generator producing electricity. Quote Link to comment Share on other sites More sharing options...
jmckinley Posted March 31, 2013 Report Share Posted March 31, 2013 Not true in the case of the C Max. It has no reverse gear, instead it runs the motor backward to reverse. Saves weight and complication of another gear. Quote Link to comment Share on other sites More sharing options...
plus 3 golfer Posted March 31, 2013 Report Share Posted March 31, 2013 Not true in the case of the C Max. It has no reverse gear, instead it runs the motor backward to reverse. Saves weight and complication of another gear.Didn't know that. So, ICE never runs when in reverse? Quote Link to comment Share on other sites More sharing options...
DaveofDurham Posted March 31, 2013 Report Share Posted March 31, 2013 Not true in the case of the C Max. It has no reverse gear, instead it runs the motor backward to reverse. Saves weight and complication of another gear. Hmm, I now recall reading that about reverse in another thread. Can you explain what is changing or switching when the electric motor switches from "drive" mode (taking elec energy from the battery and converting it to mechanical energy that moves the car) to "regen" mode (taking mechanical energy from coasting or gentle braking and converting it to elec energy that charges the battery)? Quote Link to comment Share on other sites More sharing options...
Max Power Posted March 31, 2013 Report Share Posted March 31, 2013 Most likely it is a diode or set of diodes. Diodes can be used to restrict the flow of current to one direction only. I would be curious as to how the C-MAX does this. Essentially you could use one diode and a set of relays to control which side the engine and battery components are in relation to the direction the diode allows current to flow. Quote Link to comment Share on other sites More sharing options...
ceemax71 Posted April 1, 2013 Report Share Posted April 1, 2013 Most likely it is a diode or set of diodes. Diodes can be used to restrict the flow of current to one direction only. I would be curious as to how the C-MAX does this. Essentially you could use one diode and a set of relays to control which side the engine and battery components are in relation to the direction the diode allows current to flow. The electric traction motor in the C-Max is a three phase permanent magnet AC motor. DC current from the high voltage battery is inverted into three phase AC to power the motor. The direction of the motor is reversed by changing the phase relationship of the three phase power. The speed of the electric traction motor is controlled by varying the frequency of the AC voltage coming from the inverter. The electric traction motor provides negative torque to slow the vehicle at the same time it generates power to charge the high voltage battery. Quote Link to comment Share on other sites More sharing options...
rcthomas1961 Posted April 3, 2013 Report Share Posted April 3, 2013 On my wish list is a simple software update which will display regenerative braking power recovery AS IT IS HAPPENING. This would reduce the mystery of regenerative braking. I even worked out the display. I offer it for your consideration. DR61 1 Quote Link to comment Share on other sites More sharing options...
Mr. E Posted May 24, 2013 Report Share Posted May 24, 2013 (edited) Regen does not work in reverse or in neutral. The friction brakes are actuated in these events. You can easily show this by shifting into neutral while doing a full regen stop. You'll feel a slight jolt as the regen comes out and the friction comes in. Edited June 28, 2013 by Mr. E Quote Link to comment Share on other sites More sharing options...
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