Power to the People! Electric Power That Is!



2011 Toyota Prius
 In 1999 Honda introduced the first Insight to the U.S. market and at that time the race began. The race was obviously not a very fast one since we are talking about hybrids which are not very fast. The race was a race to develop new technology that would make cars go farther on less fuel, and create less pollution. Both of these things amount to greater energy efficiency. Of all of the alternative fuel systems that are on the market right now, none have experienced the kind of growth over the last decade that the hybrid vehicle has.

1999 Honda Insight
A hybrid vehicle is one that runs on more than one power source. Hybrid vehicles use a gasoline engine and an electric motor for propulsion. Depending on the design it may be able to run on gasoline only, electric motor only, or a combination of the two. Examples of hybrid vehicles are things such the Toyota Prius, the most popular hybrid ever, the Honda Insight, and the Chevrolet Volt. Often you hear the Volt described as an electric car but the fact of the matter is that the Volt has a gasoline engine that will come on to assist the electric motor to propel the vehicle down the road, or to generate electricity for the electric motor the use. A true electric car such as the Nissan leaf has no gasoline engine at all, more on the Volt in a minute.

The gas/electric hybrids that are on the market now will always have the following components: Gasoline engine, one or two electric motor/generators, a high-voltage battery, and some kind of power inverter. All of these systems use complex computer controls to keep everything running nicely. Depending on the hybrid setup they may not have a transmission like we are used to on normal cars, or they may have one that is just like those found on normal cars. Hybrid drivetrain designs vary.

2000 Toyota Prius
Some hybrids have more complex systems that allow the vehicle to function more in electric mode only. These are what are known as series/parallel hybrids. With this design the electric motor or motors, are the primary drive units and the gas engine is there to assist and turn generators to produce electricity. Some hybrid designs cannot function at all in electric mode only. These are called parallel hybrids.  A parallel hybrid uses the gas engine for the majority of the drive and the electric motor is there to assist. A design known as a series hybrid also exists but none of the hybrids currently on the market fall into this category. The series design has no mechanical connection between the engine and the wheels. All drive is accomplished by the electric motors and the gasoline engine is there only to turn a generator. This is essentially the way modern diesel electric locomotives run.

ICE

The gasoline engine is not much different from those that we are used to in regular cars. They still use the regular principles of internal combustion in order to move pitons up and down and turn the crankshaft. The engine is usually known as the ICE (internal combustion engine). Some extra measures are taken however to help them be ultra-efficient, and work well with the electric motor/generators. Most of the time the gas engine will not have a regular starter motor because the large electric motors used to propel the vehicle can also be used to start the gasoline engine. Some times when the ICE is started it seems strange because you don’t get the usual cranking sound that you have with regular engines, it’s almost as if the engine just instantly come to life.

An A/C compressor with no pulley
Many times these gas engine will not have any of the accessories or the associated belts that are found on the front of the engine. These items can be powered directly by small electric motors. The air conditioning compressor doesn’t need to be belt driven because a small electric motor inside the compressor can be used to turn it. This is a good thing because the gasoline engine on every hybrid will not always be running whenever the car is in use. If the engine isn’t running then an engine powered device will not work. This would mean no A/C when the vehicle comes to a stop. Other things that are electrically powered are things like the power steering, the engine water pump, and the alternator. The alternator is actually completely eliminated. Why do you need a small 12 volt generator that is spun by the engine when you have 300 volt generators onboard?

Engine and transmission removed from a hybrid vehicle. The big orange cables carry the  high-voltage.
Motor/Generator

The motor generators on a hybrid vehicle are usually located in what might usually be referred to as the transmission, or between the gasoline engine and the transmission. The amount of propulsion that is provided by the electric motors totally depends on the hybrid design. As mentioned before, some hybrids only use the electric motor to assist the gasoline engine, and the vehicle will not move on electric only. On some hybrids the electric motor can propel the vehicle alone, up to about 50 miles per hour. One way to get a rough idea about how much fuel a hybrid can save is by how much the electric motors can propel the vehicle without the gasoline engine running. Most hybrids currently on the market can move down the road on electric only but most of them can’t accelerate to speeds above 10 mph without the gasoline engine coming on. Once they get up to speed there are some hybrids that can run on electric only at a steady cruise between 25 and 40 mph. As the technology gets better and better, more hybrids are capable of going faster, for longer periods of time running on electric only.

The rotor of of a brushless motor
from a hybrid. Notice how well the scraper
 sticks to the permanent magnets

The motor/generators are motors that help to move the vehicle but they are also generators. All hybrids have a mode called regenerative braking. In this mode the motor/generators become a generator to produce electricity that can be stored in the high-voltage battery. The generators are attached to the wheels which are spinning because the vehicle is moving. The generators provide resistance to stop the vehicle, and because the generators spin, they produce electricity.

The motors are able to switch from motor mode to generator mode in an instant because they are brushless A/C motors. This essentially means that they use permanent magnets in the armature (the center spinny part of the motor), and electromagnets in the stator or field windings (the part that doesn’t move, that surrounds the spinny part). When the field windings are turned on, the opposing magnetic forces cause the armature to spin and we have a motor. When the field windings are turned off, we are then spinning permanent magnets around inside a conductor, this is a generator.

The Battery can only hold D/C electricity so the A/C that comes from the generators must get converted to D/C in order to be stored in the battery. Then, as the battery feed the electric motors the power must be converted back to A/C. All of this takes place in the power inverter that is found on all hybrid vehicles.
The field windings of a brushless motor from a hybrid

Battery

Early hybrid vehicles used Nickel-Metal Hydride batteries for the high-voltage battery that powers the electric motors. Newer hybrids are starting to use lithium-ion batteries, or lithium-polymer batteries. These batteries function just like other rechargeable batteries, but they are much bigger so they can put out more voltage and amperage. Most of these batteries put out somewhere between 100 and 350 volts. Because of the tremendous amount of electricity that they can store, there are certain precautions that must be taken when working on a hybrid vehicle.
Hybrid HV batteries located under the back seat
These batteries are made up of hundreds of small cells that each put out somewhere between 1.5 to 3.0 volts. All of these cells are wired together in series which causes the voltage and amperage to be multiplied until there are enough cells in the battery pack to put out a great deal of power. Each of these cells is actually quit similar to either a cell phone battery, or a D cell battery in appearance and function. The cells cannot be serviced individually so if enough of them go bad that the battery output is diminished, then the entire battery pack must be replaced.

A complex computer control system is used to monitor and control the state of charge of the HV battery. State of charge is never allowed to be higher than 80% of its actual capacity and it’s never allowed to drop below 20% of its actual capacity. The instrumentation that the driver sees may display that the HV battery is fully charged or fully depleted but it always stays within the middle 60% limits when things are operating normally. Because of these precise controls HV battery service life has proved to be much better than originally predicted.

Just like any other rechargeable battery, it was believed that the hybrid HV batteries would have a definite service life. The average life of your run of the mill car battery is between 3 and 5 years, maybe 6 at the most, and cell phone batteries usually go bad before the rest of the phone does. With hybrids first being introduced 13 years ago by Honda and Toyota, many of these first hybrids have well over 100k miles on the odometer and they are still running around on their original batteries. Eventually they can still degrade to the point where they don’t hold a charge and need to be replaced, but if they last for 15 years and 150k miles, or more, it may not matter if they need to be replaced.

So how do they drive?

Very well, actually. Despite what people say, most hybrid vehicles drive very nicely and have plenty of pep. The amount of power is usually not any different from a similarly sized vehicle. Some of the ways in which a hybrid functions might be very different and require some time to get used to. Every time you pull up to a stop the engine will shut off if it has been running. This is the idle stop function and it helps to save fuel. When you are waiting to turn left across traffic and the engine isn’t running it may seem a bit unnerving at first, but as soon as you lift your foot off the brake pedal to hit the accelerator the vehicle will move and the engine will start up right away if it is required.
Prius controls require a bit of explanation.

Some hybrids such as the Honda Civic Hybrid or Ford Escape Hybrid feel very much like a normal car. All of the controls are familiar and no special instruction is needed to get the car started and moving down the road. Hybrids such as the Toyota Prius and Chevy Volt are a bit different and may require a new driving lesson. Once you are moving down the road however, all hybrids handle well and drive nicely.



Weighing the Cost

One of the great debates surrounding hybrid vehicles is whether or not the owner of a hybrid will actually save enough money on fuel to make up the extra cost involved in buying a hybrid, versus buying a normal gasoline powered car. All of this depends on how many miles the vehicle is driven in a year. Using the Civic hybrid for an example we can look at some numbers to figure this out. The reason that the Civic Hybrid is a good example is because we can compare the exact same car in hybrid form, regular form, a high fuel economy HF version, and just for the fun of it, we can look at the natural gas powered Civics as well.
2012 Civic Hybrid
All of the cars that we are comparing here are similarly equipped as far as the normal whistles and bells are concerned. They all have automatic transmissions, power windows and door locks, similar audio systems and other creature comforts, but they are not exactly alike. According to Honda’s website the pricing and the estimated fuel economy breaks down in the following manner:
  •          2012 Civic EX (the normal gas powered Civic)             $21,505    39 mpg
  •          2012 Civic Hybrid                                                        $24,505    44 mpg
  •          2012 Civic HF (the high fuel economy model)               $19,455    41 mpg
  •          2012 Civic GX (natural gas powered)                           $26,155    38 mpg
With these figures and some arithmetic you can see that if the driver puts 15,000 miles on their car per year, and gas is $3.00 per gallon, it will take 25 years to save the extra cost for the Hybrid. This shows us that buying the Hybrid is not worth it. The hybrid version only saves the average driver about $100 a year on fuel cost but the Hybrid purchase price is about $2500 more than the EX. The HF is probably the best value of all of the Civics because the MSRP is lower than that of the normal EX, and it gets better fuel economy.

A civic that runs on natural gas is more practical than the hybrid.
The GX is the compressed natural gas (CNG) powered Civic. This one is the most expensive but the fuel is only about $1.50 per gallon, cheaper in some places, more expensive in others. The time to make up the difference with a CNG powered civic under the same terms is about 10 years. If, however the cost of gasoline goes back up to $4.00 per gallon, and you live in a place where natural gas can be purchased for $1.05 per gallon, and your drive 20,000 miles a year, it would only take 3 years to make up the cost difference.

Plug-In to Better Fuel Economy

Plug-in hybrids represent the next evolution of the hybrid vehicle, and this feature may be the thing that allows hybrids to become a very legitimate alternative. The thing that makes a plug-in hybrid different is the fact that they can typically run much faster and much farther on electric motors only. The Chevy Volt for example can go about 40 miles at speeds up to 40 or 50 mph on the electric motor only. This means that the gasoline engine would never come on. If your daily compute is 20 or 30 miles round trip, you could drive to work and back, maybe run a few errands along the way, and never use any gasoline. When you get home you could plug your car in for the night and in the morning it would be all charged up and ready to go.

The Chevrolet Volt is actually a hybrid and not a true electric.
If you want to drive a longer distance, the gasoline engine comes on as needed to generate power for the electric motors and to provide mechanical assist to the electric motors. This means that you could drive the car for several days on electric only, and then just use gasoline on the weekends for a road trip. Fuel economy numbers have been difficult to calculate because of the way these things work but estimates are generally somewhere between 50 and 100 mpg.

Currently the Volt is the only plug-in hybrid on the market but Toyota will be releasing a plug-in Prius, and Ford will release a plug-in Fusion Hybrid sometime in 2012. Most other manufacturers that currently offer hybrids will be adapting a plug-in feature to their models at some point.

The Volt carries an MSRP of about $41,000 which is pretty steep for a small sedan, and makes regular hybrids look like a good deal. Chevy released the car to market after the federal government had taken over the bankrupt GM. The Feds will give you a $7500 tax credit if you buy a Volt. That only brings the cost of a new Volt down to $33500 which is still a lot of money for this type of car. Having U.S. tax payers fund a certain percentage of your new car purchase also seems somewhat immoral. If you are wealthy enough to spend over 30k on a new car what entitles you to receive another $7500 from your neighbors?
Plug-in Prius.
The new Prius plug-in will carry an MSRP of $32,000. The tax credit that this car will qualify for is probably going to be about $2500 (why less than the Prius?) bringing the cost of the car to the purchaser down to $29,500. Better than the Volt but still a lot to pay for a small car such as this. Pricing for the Ford Fusion 
plug-in has not yet been announced.

Plug-in hybrids sound great but considering the cost it’s hard to justify buying one as well. Whne they bring the cost down then maybe we will have something worthwhile. The other thing to consider is that the electric power charged to the batteries when the car is plugged in has to come from somewhere and still has to be paid for.

What about the Horse and Buggy?

While it seems fairly obvious that hybrid vehicles are probably still impractical for the most part it helps if we put things into perspective. Imagine the year is 1900. It has been 14 years since Karl Benz built his motorwagen, which is considered to be the first modern car powered by an internal combustion engine. Other upstarts have been around for just a few years and Henry Ford is doing a lot of experimentation, but the Model T is still 8 years away. Some of the wealthy are just beginning to run around town in these noisy little horseless carriages from names such as Ransom E. Olds and David Buick.

At this point, many say that these might be the future, but such a thing is hard to imagine and here are some of the reasons why. These little motor cars are slow, expensive, reliability is dubious, and no real practicality can be seen in owning one. When they break down and you take it to the blacksmith shop they aren’t going to know how to work on them. They are so complicated compared to what we are used to that it makes no sense to say that this will one day be the standard. Those that currently own them are trying to make a statement about themselves, or they are just trying to show off and act like they are ultra-modern.  Some might say, “Just give me a good team of horses and a sturdy wagon or buggy and I can get around just fine for the rest of my life.”

Now reread the above paragraph and substitute the word blacksmith with mechanic, and the words, team of horses and a sturdy wagon or buggy, with normal car, and you could apply the message to some of the negative viewpoints surrounding hybrids today. The bottom line on hybrids is that this technology is new and still unproven, and still needs to develop further. Current hybrids are not good enough to be the future of transportation, but a future hybrid that is much better and much cheaper might be. Let’s sit back and see what happens.
Porsche Cayenne Hybrid

Power to the People! Electric Power That Is! Rating: 4.5 Diposkan Oleh: repairsy car