Future with Hybrid Electric Vehicles
Electrical machines were initially operational about 150 years back for workshop type jobs or for air/water circulation etc. Their applications for transportation (rail as well as road) were practiced about 125 years back. Lots of ups and downs have been experienced during this long span of time. Inventions of radically different technologies were at the service of mankind for planning better products. Added to that have been driving forces due to intense international competition to innovate. This has led us to the present wisdom in our subjects so as to produce ‘state-of-the-art products’. Whatever was not even dreamt about 50 years back is in popular use today. Glamorous examples of these are Computerization, the Internet, mobile communication, applications of solar power, etc. VLSI(micro-electronics),nano-technology are some examples of the latest path-breaking areas which changed our lifestyle drastically. During the past two decades, we have been convinced that what is constant is ‘change’. These technological changes have been too many. Further, they occurred too fast to sustain. Still, we gladly cope up with this, by learning / adapting new systems. That is how we enjoy the sweet fruits of progress.
Coming back to the issue related to Vehicles, we are a witness to dynamic changes. Coal/steam-driven trucks/ buses were in use up to 1950. Diesel-based Transportation (Road as well as Rail) continues to be the first choice, after 1960. However, rail traffic is getting speedily replaced by electric traction for which the process started about 20 years back. After 2010, it is the turn off road vehicles to choose Electric Drives. There has been a strong will to operate road traction using energy in electrical form. Naturally, it will start with smaller sizes. As an example, Electric MoBikes have become fairly popular during the past decade.
Talking about cars, the western world has different constraints and priorities. In smaller communist countries, fossil-fuel-based generation cannot be afforded for want of foreign exchange. They prefer to pay higher energy tariff for solar- or wind- the power to minimize foreign exchange required for importing the crude oil.
As a result, there are consistent and hectic efforts since two decades to strike a solution in the form of an Electric car acceptable to the majority of small car users. The first effort resulted in such a car with its 30 km run with a fully charged battery. Full charging of the battery needs four hours with a powerful
( & hence costly) charger. This needed a drastic improvement. In the mean time, use of solar energy for powering the EV started being attractive. During sunny hours, the charged battery started powering the car for 20 km more due to the solar power input while driving on the road through the panels mounted on the vehicle top. This gave a positive boost to the acceptance of electric car. Solar panel also looked after battery-charging during day hours, resulting into money-saving. Further progress in all the supporting directions can be enumerated as follows: (1) Super-Capacitor has been a new product since 2005. It has its energy density one lakh times more than an ordinary capacitor. This proved to be an excellent companion for the battery. So much so that a Hybrid electric vehicle bought today will have a Battery Management System [BMS] in place of Battery. BMS is nothing but a Battery with the lower Amp-Hour rating, a Super-Capacitor, and a controller to monitor the currents shared by these two. The programming in the controller ensures that the battery will never be required to supply more than its rated current even if the load demands. In such cases, the controller ensures that the excess current is fed by the super-capacitor, to retain the full life of the battery. (2) Efficient, controllable, and trouble-free motors must be used as the main drive. One typical popular motor is the Brushless D C Motor, popularly known by its short form BLDC. (3) Hybrid Electric Vehicles (HEV) should have one Electric Drive, and another Bio-fuel-driven Internal Combustion Engine. The obvious purpose is to avoid consumption of fossil-fuels. (4) Applications of HEV’s as resources should be maximized. Whole-hearted efforts are ‘on’ in the USA [Project period: 2010 to 2020 ] to have a blueprint for the master-minded beneficial project. This aims at HEV’s earning revenue when ‘parked’ and ‘plugged-in for battery-charging’. This interfaces the vehicle with the grid through its intelligent charger, which caters to the needs of the grid as well as the HEV. If HEV-Battery is weak, the grid will charge it (G2V power), and HEV will have to pay for this energy. While If the grid is in need of power (as in the evenings) and if the HEV-battery is strong enough, the car will feed power to the grid (V2G power).Car-owner will be paid money for this energy. Technically, this is known as a fast-responding ‘spinning reserve’. Grid also will find this method as economical. Further, the system control/communication will select the geographical location of the car(s) from which this support should be preferred. The grid will operate under an ideal condition of “Injecting power exactly at the needy location”. Effectively, this fulfills the recent need of “distributed generation”, for better grid performance.
Links of Development:
(A) Intelligent Charger: First trigger started with a smart charger introduced in around 1990, in the USA. The focus was on using a common battery for the car and the emergency inverter. Smart charger with the car had a plug-in facility. As soon as the car is parked in the garage, the owner used to plug-in the smart-charger to the mains for battery-charging. In a way, the battery is interfaced with the grid. Depending on the situation, action would be decided by the smart charger. With the AC supply on, the battery would receive energy till it is fully charged. In the case of power failure, smart action will result in the battery feeding the selected important lamps/ fans / TV / Phones, etc. Money is saved in terms of cost of one battery. In their lifestyle, Americans find this suitable.
Next development was for the intelligence required in the system when it was imagined that a strong car battery can pump power into the grid for supporting it during peak load hours. ‘Proper power-electronics control, proper timings, proper conditions of the systems and optimally monitoring energy flow in either direction are some of the parameters of interest’. For this, now an intelligent charger is required. Initially, this was mocked at thoroughly, since the energy transactions were poor.
However, the caretaker team had a strong determination. As a result, California State Electricity Board paid money to the car-owners at Los Angeles, in 2011. This strengthened ‘rays of hopes’ for the advocates of V2G power.
(2) More Energetic Electric Cars:
(a) The progress of Hybridization: As is rightly conceived, an electrical system creates a panic situation in case of failure. The situation is more horrible for a car, since one is likely to be stranded at an unsafe spot, at an odd hour, and in a fearsome atmospheric condition like heavy rains/snowfall. There has to be another reliable source to power the vehicle to reach a nearest safe spot, say, for 10 km. There is no alternative but to add an Internal Combustion Engine (Petrol / Diesel driven) of about one-tenth rating of the vehicle. Such a Hybrid Electric Vehicle(=HEV) was readily accepted by the customers.
In the next stage of development, today’s HEV has a different meaning. The Brighter side of electrical systems is that they have higher efficiency. Today’s HEV has an electrical system rated to drive the car.
Since the battery is powering the car, its energy is depleted as the car is driven. When the energy reduces to the allowable low-limit, the I.C.Engine takes over automatically, without a need for the driver to act. The I.C.Engine drives the vehicle, and in addition, charges the battery. This goes on till the battery gets charged to a predetermined (high-) level. Then, the car is again converted to the battery-powered electric vehicle. Thus, there is no need for breaking the long journey.
Today’s HEV is, thus, more energetic. It has two power sources of matching rating. In fact, the I.C.Engine is stronger amongst the two.
Such a strong HEV can more effectively participate in V2G power.
(b) Future role of PHEV: In a project of international relevance, a strong American group is working (project period : 2010 to 2020) for technical design of control/communication set-up required at the grid-level, GSM (=Global System for Mobile Communications) / GPS (=Global Positioning System) required, cost of setting up of HEV parking lots including the Interface system required for pumping V2G power, and a strong will to use Biofuels for these I.C.Engines. Then, there is a strong recommendation that such parked cars will pump enough power (through suitable power electronic systems) to the grid during its peak-load-hours. Just for clarity, a city of the size of Nagpur will have 60 such parking lots for PHEV’s(= Plug-in Hybrid Electric Vehicles) distributed over the city. If PHEV rating is 40 kW, each car is capable of generating a power of 40 kW. What a strong support to the grid, per car? Naturally, the intelligent charger, as an additional gadget, should not be too costly for the car-owner.
( c ) A popular version of a small car: From the concerned technical literature, car-body is likely to be almost fully covered by decorative solar panels. Such cars are likely to be the people’s cars in small countries in Europe. They will be one up in V2G power- issue. In case this dream is realized, PHEV will not be a liability but an asset to the owner who will earn appreciably by selling power to the grid during its hard hours. In return, the grid will not be required to buy power from ‘spinning reserve’ from fixed locations. It is now possible to decide ‘how much power’, ’from which location ‘, and ‘how long’.
No doubt, Americans have systematically progressed to reach the aim by 2020.
If we surf the NET rigorously, we shall whole-heartily agree that Japanese / German / Swiss / French /Asian Carmakers have many similar innovations to attract the market to sell more and more electric vehicles. Let us wish them all the best.
Whatever has been said about cars is applicable to buses. It is well known that only battery-powered city buses will operate in India by 2020. This entire issue then becomes still vital!
Two photographs below show the two recent issues which have been perfected in 2015 & 2016.
Jai Hind !