are the electric motors used by the toyota prius dc or ac?
The motors work on three-phase alternating current, with powerful permanent magnets. The job of the inverters and the control electronics is to convert the DC supply from the battery to a suitable voltage (up to 500V on 2004-2007 Prius), current and phase for the desired torque on the motor generator. This gives the control electronics very precise control over the positioning, as every single change in the current in the coils is under the computer's control - when the engine stops, it will actually 'position' the engine shaft in the optimum position for smoothly starting it again, and the 'hill start' feature has such precise position control I often have to double-check if I took the parking brake off... It probably could have been designed using either, but I would expect DC motors to be more dangerous, as a short circuit or broken component somewhere could apply a constant voltage and make it fly off without warning (whereas applying a constant voltage on one of the coils on an AC motor locks it in place...)
Be a bit careful here. The brushless DC motor is actually an AC motor. You need an inverter to drive it! A better name for this type of motor would be: “synchronous permanent-magnet AC motor.” The Toyota Synergy Drive motors use permanent magnets. Some call it DC some call it AC. It is not a true AC induction motor because it has magnets. Permanent magnet motors tend to cost more than induction motors, but they are easier to control.
To help you with the confusion of AC or DC, it depends on at electrical power input point you look at it. The motor systems includes a permanent magnet synchronous motor driven by an inverter controlling the motor. The battery supply, which is DC, goes to the inverter then it is converted to variable-frequency AC power by the inverter before feeding the permanent magnet synchronous motor. Hope this helps!
The motors are DC. There are inverters, though, for various functions, like the accessory plugs and charging the little 12V starter battery. The main traction battery puts out some 238VDC and the inverters step down the voltage as necessary (like for the CPUs, too, of course). The motors get the full Monty, though the current varies as necessary. Hope that this helps.
