Electric Mobile - handmade electric car.

Most of EV conversions are made using series DC motor. It is impossible to get regenerative braking with such a motor using ordinary PWM controller. Most EV owners thought like this. Actually I did the same. To make a device with separately Field and Armature exciting seemed to be a right decision. But it takes PWM controller to increase 3 times in size and price. And $1200-$1500 for 400A series dc motor controller would be a nonsense. So, we want to regenerate braking power back into the battery on one hand, but the cost of the system would be too great, on the other hand. The problem was left until future times… But now this time has come.

Lets look at the PWM controller and series dc motor wiring first.

The field and armature winding are connected in series. This is ordinary and optimum connection method.

The principle of series dc motor regeneration is to left the motor “as is”. Connection method is still the same. PWM controller is the same, too. For regeneration we need to connect special device that excites the “Fileld” to turn the motor into generator.

The problem of such a connection is that current of regen should overcome the current of Field exciter (I= Igen- Irec). It will be a nice decision to separate these currents through diodes.

In such a circuit Irec and Igen will flow in different circuits without subtracting. The power of regenaration will depend on motor rpm and Irec. That means we can regulate braking power with the help of Irec.

Practical experiment have such results:
traction nominal motor power 7.2kW (series wound dc motor DC3.6\7.2\14)
battery voltage 110V
regen current at 4% downhill (initial speed 50km/h): 60A (110V)

___________________________________________________________________
Some EV users do not believe that my regen system works. You can check the principle. You will need: two wires 50-70mm2 aprox. 2m long, AC 220V 180A breaker; 6V or 12V battery, free-wheeling diode like BYV72EW-200 (VD1.1). You need to have series winded dc motor, with appropriate PWM controller (Curtis, Alltrax, Kelly etc) connected. It is convenient to install additional battery with circuit breaker on passenger’s seat. The wires should be long enough to connect add.battery to the Field. aprox. 2m long, AC 220V 180A breaker; 6V or 12V battery, free-wheeling diode like BYV72EW-200 (VD1.1). You need to have series winded dc motor, with appropriate PWM controller (Curtis, Alltrax, Kelly etc) connected. It is convenient to install additional battery with circuit breaker on passenger’s seat. The wires should be long enough to connect add.battery to the Field.

Connect breaker and additional 6-12V battery as shown in the schematic:

VD1.1 -- fast diode (for ex. BYV72EW-200 few pcs in parallel)

Kelly controller wiring:

Kelly controller wiring with additional regen brake battery

When trying to get regen with Curtis controller, you have to be sure that “Main” contactor is ON but PWM doesn’t run! Otherwise regenerative current can’t flow into the “Traction Battery” pack:

Curtis 1231C/1221C

Run the vehicle to reach 1500-3000rpm on motor rotor. After the vehicle reaches the necessary speed, depress the accelerator pedal and switch on the breaker to excite the Field winding. You should see the current charges traction battery on your amp-meter. There will be no regen if the motor speed is not enough. So, don’t hurry to increase the speed significantly. Start to check regen from slow speed, increasing by aprox.+5 km/h.
____________________________________________________________________
Dear visitors! We started to collect orders for regenerative braking devices for first quarter of 2011.
The price is $300/pc. Prepayment is $100.

Похожие темы:

• Electric Tavria Недавно я писал про упоминание в СМИ об Электро Таврии, ...
• Selecting power source for electric vehicle During reviewing the list of products of ThunderSky, I have...
• Электро Волга ГАЗ-21 Приветствую вас. Сегодня я хочу представить вам новый электромобиль, который...
• Про чесность СМИ и Электро Таврию Украинский “кулибин” легко сделал из “Таврии” электромобиль. В последнее время...
• Таврия-Электро:Стыковка электродвигателя и коробки В нашем примере картер коробки имелся “на руках”. Благо, от...