|
JFTR let me try to clear this up, I never said this technology wasn’t “cool”, just complex.
Let me try and touch on it without writing a book. Hybrid systems do vary, but here is a typical application. You have a normal Internal Combustion Engine (engine) with all the sensors and controls associated with it (but no DC starter or alternator). Next is a computer controlled clutch pack (CP2). Then a three phase AC induction motor (motor). Another computer controlled clutch pack (CP1). And finally the computer controlled trans-axle driving the wheels. The motor is driven by an inverter that has three high current F.E.T.s (Field Effect Transistors) mounted on a “cool plate” circulating engine coolant to keep them from overheating. The inverter converts the DC battery pack current into three phase AC current (three AC phases separated by 120 deg.) to drive the three phase AC motor. OR when in regenerative braking mode or running down the highway with the engine running, it converts the 3 phase AC back into DC current to charge the battery pack.
You get it the car and turn the key, the computer energizes gas filled, high current relays to connect the battery pack to the inverter. If the computer senses ANY latent current from either + or - battery pack lead to the chassis, electrical ground, etc. it will cause a fault and de-energizes the relays (car DOA). You step on the gas, CP1 engages and inverter provides current to motor and trans-axle drives wheels moving car forward. If you exceed around 20 MPH the computer now engages CP2 turning engine and computer starts it running as a normal I.C. engine. Motor is now acting as a generator charging battery pack through the motor. You slow down to less than 20 MPH, computer dis-engages CP2 and shuts down the engine. You touch the brakes, if CP1 is not engaged the computer does so so the motor can recharge the battery pack through the inverter ala re-generative braking which also helps slow the car. That is a lot of controls and sensors in addition to a normal engines systems. If one F.E.T. in the inverter fails you’re DOA. If the clutch pack 1 solenoid or clutch fails you’re DOA. If anything associated with clutch pack 2 fails you will soon be DOA, etc., etc. This is a lot of complexity for not that great of MPG gain IMO. My son’s aforementioned ’92 Lumina still gets 30 MPG on the highway and it took 4 months for them to figure out what was wrong with it. For me it is too much for too little, not even factoring the resources it takes to build a hybrid.
But then again maybe I’m just a technophobe that doesn’t understand new technology.
|