axt hybrid-power

What is AXT HYBRID-POWER ?

Imagine 20-50kw of additional power, but with hundreds of NM extra torque, all while burning less fossil fuels AND not having to worry about emissions testing your modified vehicle... Torque delivery is the key here..

Normal ICE engines produce torque in a rather non-linear manner, with an engine being designed to provide optimum torque ( and hence efficiency ), at its anticipated most commonly operated engine RPM. This ( very generally ) is in the 2000-4000 RPM range. Outside of this range, engine efficiency drops off significantly, resulting in higher fuel consumption and greater emissions. Engine designers then have to add further equipment and vehicle dynamic changes to compensate / address this. The end result being the best "compromise" between performance and efficiency/emissions compliance.

As an example, when entering a highway, (especially with traffic control lights), virtually full vehicle throttle input is required to accelerate up to speed to safely merge with the traffic. The fuel used in this effectively "short" event (10-15 seconds) may be as much as the next 10 kilometers of highway coasting/cruising fuel usage. As you can see, the ICE engine is quite efficient cruising, but during acceleration and load changes, it really uses the fuel...

Now lets add an EM power source to the equation but same scenario - Standing start acceleration has an additional INSTANT 2-300Nm torque adding to the acceleration, getting the vehicle off the line and up to speed. This much EM torque in addition to the ICE engine delivered power will result in EXTREME acceleration. Most of us would find this acceleration too much for normal driving, and would simply reduce the amount of accelerator pedal input. As soon as we do this, the vehicle accelerates still at an acceptable rate, but the actual power is being delivered by the EM , allowing the ICE engine to operate using less fuel while it gets to its optimal operational rev range. Once at cruise, the EM reduces the delivered power allowing the ICE engine to maintain speeds.  Some of us would actually "enjoy" the extra acceleration, however, our traffic rules still pretty much limit how fast we can go. The big bonus here, is that 10-15 second event, now might be 4-5 seconds, with a decent adrenaline burst :-) AND still an effective saving of 8-10 seconds of heavy fuel use getting to the required speeds.

The above is just ONE extreme driving scenario, but in reality, this occurs thousands of times in our normal driving, especially during peak hour stop/start traffic. While we may not be going to full throttle, we are operating the ICE engine well outside of its optimum range. This is where the EM comes into its own. Even the most conservative ICE engine driving styles cannot match the EM, simply because the efficiency is not there to start with..

The laws of general relativity and motion still apply to an EV-Hybrid modified vehicle however. We still need to "get" that extra power at some point. Firstly, the EV is powered by a battery pack, sized to support the expected vehicle application. We've also got to keep that battery charged to a state that the EV can provide the power. The key here is to use the ICE engine to top up the battery, but only while the ICE engine is in its most efficient operating state. Secondly, we can take advantage of other vehicle dynamic conditions. Conditions such as downhill coasting and braking make use of regenerative braking, effectively using the EM as a generator, resulting in the vehicle slowing AND recharging the battery pack. Regenerative braking is something an ICE engine can never do!