The Solectria E-10 has 2 AC drive motors belted to a common drive shaft. How does one sync 2 motors connected in parallel? Each motor has it's independent drive electronics. The drive electronics are much like a variable speed drive, in that they make AC voltage of different frequencies, in response to the accelerator position. I asked the question about syncing motors in the yahoo group for Solectrias. The response: Each motor has a rotary encoder on the motor rear shaft. Hence the controller knows the speed of the motor. An induction motor is commanded a speed, and and the actual speed is known, the difference in speeds is called the slip- a few hertz. This slip, has the rotor slipping through the magnetic fields created by the stator. Long story short, a field is induced in the rotor, and it is the interaction between the 2 fields that creates torque. Syncing is not an issue, so much as commanding the motor speeds to be in excess of the actual speeds, hence providing torque.
The following is a picture of the controllers. There are 3 computer connectors- a D-Sub 9 (motor encoder) and D-Sub 25 (ignition box)and a D-Sub 15 pin. The 9 pin and 25 pin connectors are common to all controllers. The D-Sub 15 is of unknown function at this time. I suspect it is for monitoring or programming.
4 EA
2EA
Electrical Schematics (Power and Control) . The Solectria EV's have the following instrumentation: ammeter (-100 amps / +300 amps), a voltmeter (180-280 V) and an amp-hour meter. The communication between the controller and the vehicle controls, and vehicle systems is through a PCB in the Ignition Box (IB). The following image is provided by the maker of the controller. The relays and pots and switches are in the IB.
Many of the connections in the IB are left blank. Not included-star/delta,tempomat(cruse control),battery current/voltage,rotor speed, LEDS, mileage indicator, star delta display. Included are the main switch, drive direction (forward/rev), recuperation off (for slippery streets), economy (which controls the driving allowable amps), driving disable, and pedal operation (how the pot is connected). The driving disable may be used to prevent vehicle motion when the vehicle is charging. Without tracing out the active electronics on the IB, suggestions for testing the Ignition board logic are here.
One of the three trucks that I am restoring, has an additional battery box in the front, for 2 additional batteries, changing the voltage to 252 V. This leads me to ask "how much voltage is too much, or too little"? Between Wolf, and a Solectria ex employee, I have the following guidelines: One is that the controller naming convention is where ACavv stands for a x 200 amps, and vv x 10 volts. So an AC230 is 200 amps and 300 volts. Wolf adds that the voltage on the capacitors within the controller, will be rated at 20% higher than the nomial voltage. Thus, the caps in a AC230 controller should be rated at 360v.
It is interesting to compare this to the DMOC445, which is the replacement motor controller from AzureDynamics (formerly Solectria). It's control schematic follows: Note that all of the circuitry that was in the Ignition PCB, is now internal to the controller.
