Alternative Hybrid-Electric Vehicle

An Alternative Hybrid-Electric Vehicle

Sunday, October 12, 2014

Unique Niche

This HEV has features that give it a UNIQUE niche. 
  • I designed it from ground-up, following the principle of operation of an Electric Power Grid, that I managed for a period of four years.
  • Its control system is designed to operate with a range of prime-movers, to include diesel-fired engines.
  • It is designed to interface with 
    • Is already "plug-in"
    • Already drives industrial machines, like the 3-phase electric drill in the video, below.

  • It is open to the inclusion of a "Co-Generation" system in trucks and buses that would collect waste energy (FREE!) from the engine's exhaust and jacket, in order to provide power to a Lithium-Bromide Absorption Chiller to air-condition the vehicle, or provide heating, as the case maybe. This displaces the need for independent sources for cooling and for heating. 
  • It uses affordable tried-and-tested and reliable 3-phase 60-Hz induction motors. This approach opens up NEW export markets in developing economies. In this manner, exported vehicles are designed for specific environments, and are more easily maintained.

This HEV uses successful engineering technologies with a view of renewable energy and other energy-efficiency technologies of the future.

Our HEV is patterned after the operation of an electric power grid. Electricity is normally delivered to the load (demand). When the demand goes down, we reduce the power output of the power plants that are connected to the grid. These power plants are called regulating plants because they increase or decrease their power output in accordance with the demand on the grid. At some point, these plants will need to be shut down because they are no longer needed. If the load goes even lower, the utility company will need to bring down the power output of the so-called "base-loaded" power plants. These are the large nuclear, coal, geothermal, and oil-fired power plants. By their design, however, they become inefficient and become unstable as their power outputs are reduced.

Under this condition of excess power, an electric utility will pump water up to a lake to convert electric energy into potential energy of the water. Now, when the load goes higher than what the regulating plants can provide, water is made to run a hydro-electric power plant to convert the potential energy of the water back into electrical energy. There is, of course, pumping and generation losses. However, these losses are found to be lower than if the utility put up more regulating power plants, and designed their base loaded power plants to have regulating capability.

Trivia: The Philippines' Kalayaan Pumped Storage Power Plant is one of the power plants on the electric grid that I managed. The Irish's Electricity Board carved the top of a hill to become an upper lake to pump water into. They also excavated the foot of that hill to become the lower lake, from which to source the water.

Our HEV operates in much the same way as an electric power grid, but with an ADDED feature. Whenever we step on the brakes, it recovers the kinetic energy of the vehicle and converts it into electricity. Then it stores this electrical energy in a battery system.

The software on the laptop manages this activity.

The next question that might come to mind would be:

"How do you decide when to run the engine, the generator, the motor, and the charger (brakes)?"

CLICK HERE to view the Guiding Notes of the Coordination Meeting of January 19, 2004. All the hardware and the software must comply, and have complied with each of the boxes on that table. You will see sequential actions and concurrent actions that each of the participating modules perform at every step of the way. Note that thinking has progressed since 2004, and there will be need to update this chart.

Now to continue with the overview of the process. 

Let us take up the Efficiency Map. This to my mind is the most important chart that an HEV designer must adhere to, very closely. Let us view the chart at this URL:

Efficiency Map. This Ford engine has an efficient operating range of 1200 to 3000 RPM at a brake torque of 115 to 145 Nm. Within this range, its fuel consumption is about 245 grams per kWh. If we operate the engine at all, it will be operated at this most efficient operating range. 

If the vehicle requires load outside this operating range, our design requires that we introduce the corresponding load. Our Controller/Dispatcher activates the charger, which acts as a load to bring the operating point back to the most efficient operating range.

Now for an overview of the milestones.

This is a theoretical dispatch chart based on our specifications. The control software dispatches the components/modules of the HEV, using this chart.

The engine starts operating only from 70% to 95%, the range that is indicated in the engine's "efficiency map." The electric motor is the SOLE prime-mover outside this range, i.e., from rest to 70% and from 70% down to rest.

The charger presents itself as a "variable load." The engine will be started if the shaft demand is more than the capacity of the motor. This will be about 30% load on the engine. Since we want the engine to be loaded a minimum of 70%, we will need to operate the charger at a level of 40%, to bring the engine to its efficient operating range, as shown in its "efficiency map."

    The paragraph, below, gives a description of the dispatch chart

    • The motor takes the vehicle from rest to about 40%
    • At that point, the engine is started, and starts to rapidly pick up load
    • The motor relinquishes it prime-moving power to the engine and, at the same time, the charger increases its charging current to serve as a load to the engine
    • The motor and the charger provides the net additive or or loading power to the engine, as desired
    • The engine, then, stays at 70%
    • An increase in the net power to the wheels is accomplished by decreasing the loading effect of the charger (reducing its charging current to zero)
    • The motor starts to pick up load when more power is required at the wheels
    • The engine will ramp up its power to its maximum allowable overload, when more power is required at the wheels
    • At this time, the motor will have already reached its maximum output and stays at that condition
    • The system will simply retrace its steps when the load on the wheels is decreased until the HEV comes to a full-stop
    NOTE: For this prototype, the electric motor is rated at about 30% to 40% of the capacity of the engine. In my future design, I will bring the motor capacity much higher than this prototype. The charger and the battery ratings will also need to be increased. Accordingly, my engine's rating will be reduced, enough to overcome the drag at the vehicle's rated speed, with due consideration to headwind.