25 ‘Tata Starbus Hybrid Electric Bus’ Handed Over to MMRDA

[Akash1886]

Maharashtra Chief Minister Shri Devendra Fadnavis formally hands over 25 ‘Tata Starbus Hybrid Electric Bus’ from Tata Motors to MMRDA

The launch ceremony was presided by Shri Anant Geete, Union Minister Heavy Industry and Public Sector Enterprises


Hon’ble Chief Minister of Maharashtra, Shri Devendra Fadnavis inaugurating the new Tata Starbus Hybrid Electric Bus delivered to MMRDA by Tata Motors


Mr. Girish Wagh, President - CVBU, Tata Motors handing over the Tata Starbus Hybrid Electric Bus to Hon’ble Union Cabinet Minister for Heavy Industries and Public Sector Enterprises – Shri Anant Geete, Shri Devendra Fadnavis Hon’ble Chief Minister of Maharashtra in the presence of Shri. Urvinder Pal Singh Madan, IAS, Metropolitan Commissioner, MMRDA





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Key Highlights:

First Indian manufacturer to commercially deploy Series Hybrid technology in India

Chassis with new generation BS IV Engine

All new stylized body design

First in the industry: Full Low floor bus Configuration

Enhanced NVH system

Most Advanced Lithium Ion batteries in Automotive Industry (Prismatic Cell)

Tata Motors Proprietary New Generation Telematics system for remote diagnostic

Mumbai, March 16, 2018: Tata Starbus Hybrid Electric Bus with Full Low Floor configuration from Tata Morors’ was today formally handed over to MMRDA at the launch ceremony in Mumbai today. Developed indigenously, the Tata Starbus Series Hybrid bus comes with global design standards and looks stylish with a premium and robust road presence. The Tata Starbus Hybrid Electric Bus runs on dual power, i.e. diesel and electric and is economically viable, safe and environmentally friendly. It comes loaded with class-leading comfort and safety features for passengers. It is the future of rapid urban mass transportation system. The vehicle also complies with all UBS-II (Urban Bus Specifications), AIS 052 (Automotive Industry Standards) and CMVR (Central Motor Vehicle Rules). Mumbaikars can experience the first ‘Made in India’ Hybrid Buses on the Bandra Kurla Complex route in the city.

Commenting on this milestone, Mr. Girish Wagh, President, Commercial Vehicles Business, Tata Motors said, “With sustainability at the heart of our innovation programme, we at Tata Motors, have led technology changes in the Indian commercial vehicle industry over the last six decades. The Tata Starbus Hybrid Electric is India’s First Series Hybrid Electric Architecture Bus and is a testimony to our technology prowess and deep understanding of our customer requirements. We are committed to developing low-emission buses that make substantial contribution towards sustainable urban transport. We will continue our work on electrification and alternate fuel technologies and engage with the government and regulatory authorities to promote these smart technologies and develop products further strengthening the future of Green Mobility in India.”

Dr. AK Jindal, Head Engineering (Electric and Defence) CVBU, Tata Motors said, “Tata Motors is the country’s largest bus manufacturer, with a complete range of transit vehicles that meets every need, arising from day-to-day travel. The company continues to be a leader in the segment not just by setting technological benchmarks but by also adapting innovations effectively to suit Indian travel conditions. With an entire range of coach designs, e.g. microbus, intercity and touring coaches, luxurious inter-city travel options, to safe transport choices for school going children, Tata Motors is best suited to cater to customers’ needs with an entire gamut of day-to-day mass passenger transport solutions.”

Tata Motors is India’s No 1 Bus brand and it is constantly evolving with needs of its customers. The Starbus Hybrid Electric Bus is step towards providing State Transport Undertakings (STUs) a Smart Public Transport Solution with class-leading and greener technology and best-in-class comfort and safety features for passengers.

About Tata Motors

Tata Motors Limited, a USD 42 billion organisation, is a leading global automobile manufacturer of cars, utility vehicles, buses, trucks and defence vehicles. As India’s largest automobile company and part of the USD 100 billion Tata group, Tata Motors has operations in the UK, South Korea, Thailand, South Africa, and Indonesia through a strong global network of 76 subsidiary and associate companies, including Jaguar Land Rover in the UK and Tata Daewoo in South Korea. In India, Tata Motors has an industrial joint venture with Fiat. Engaged in engineering and automotive solutions, with a focus on future-readiness and a pipeline of tech-enabled products, Tata Motors is India’s market leader in commercial vehicles and among the top in passenger vehicles with 9 million vehicles on Indian roads. The company’s innovation efforts are focused on developing auto technologies that are sustainable as well as suited. With design and R&D centres located in India, the UK, Italy and Korea, Tata Motors strives to pioneer new products that fire the imagination of GenNext customers. Abroad, Tata cars, buses, and trucks are being marketed in Europe, Africa, the Middle East, South Asia, South East Asia, South America, Australia, CIS, and Russia.

Regards

Akash

 

[gearhead2]

A very encouraging effort from TML, and very definitely puts TML on the world map of EV manufacturers! From press reports it seems that most mfrs in India have EVs in the pipeline & their launches are more or less imminent.

 

[carcommentor]

Maharashtra Chief Minister Shri Devendra Fadnavis formally hands over 25 ‘Tata Starbus Hybrid Electric Bus’ from Tata Motors to MMRDA
​

Key Highlights:

First Indian manufacturer to commercially deploy Series Hybrid technology in India

Chassis with new generation BS IV Engine

All new stylized body design

First in the industry: Full Low floor bus Configuration

Enhanced NVH system

Most Advanced Lithium Ion batteries in Automotive Industry (Prismatic Cell)

Tata Motors Proprietary New Generation Telematics system for remote diagnostic



Regards

Akash

While it is a good effort, it should be noted that the battery pack is only 9.28 kWh (320*2V*14.5 Ah). It is more a diesel bus than a hybrid bus. Even Mahindra eSupro has a bigger 14.4kWh pack.
Based on Carnegie Mellon University's S Sripad, V Viswanathan EV formula and with a frontal area of 8.71 m^2, weight of 20,000 kg ( including 31 passenger and 1 driver), average speed of 40kmph, coefficient of drag of 0.42, bus will need 9.63kWh battery pack to travel just 16 km. So pretty much 94.67% (284 kms of the 300 km) of the range uses diesel.

 

[jagrover]

Why there should be range for a series hybrid ? As long as Engine is running, generator will power the induction motors, right ? On what basis is the range calculated ?

 

[carcommentor]

Why there should be range for a series hybrid ? As long as Engine is running, generator will power the induction motors, right ? On what basis is the range calculated ?

Neither the alternator from diesel engine nor the back emf from regenerative braking or both combined can charge and keep the battery constantly above 30 % State of Charge (SoC). The claims in some websites (Eg Rushlane) that out of 300Km range, 50-60km will be in ‘full EV mode’ is ludicrous. The only way that can be achieved by the current battery is by reducing the vehicle + passenger weight to 6,996 Kg and drive at 10km/h speed !
If we consider just the bus weight and driver weight ( 18,000+ 70 kg) =18070kg and run the bus at 10km/h speed, to achieve a ‘Full EV’ of 50km range, we need 23.20 kWh Battery.

 

[gearhead2]

Neither the alternator from diesel engine nor the back emf from regenerative braking or both combined can charge and keep the battery constantly above 30 % State of Charge (SoC). The claims in some websites (Eg Rushlane) that out of 300Km range, 50-60km will be in ‘full EV mode’ is ludicrous. The only way that can be achieved by the current battery is by reducing the vehicle + passenger weight to 6,996 Kg and drive at 10km/h speed !
If we consider just the bus weight and driver weight ( 18,000+ 70 kg) =18070kg and run the bus at 10km/h speed, to achieve a ‘Full EV’ of 50km range, we need 23.20 kWh Battery.

Thank you, carcommentor! Yours is indeed the kind of feedback that is needed in clearing the obfuscation & sleight-of-hand marketing that is rampant today in the field of EV & hybrid vehicles!

EVs & hybrids are certainly the way forward keeping in mind the dwindling fossil fuel resources, but there is no need for mfrs to give sugar-coated pills to the unwary public!
I am a mechanical engineer - marine engineer, actually - and like most of us, our electrical base remains a sore point!

So, once again, thanks for this useful post!

Regards,
Shashanka

 

[m_sherbet]

What about the specifications of the electric motors used? In a Hybrid vehicle, the electric motor(s) and the ICE work together, helping each other, in moving the vehicle. Together if they manage to reduce running costs by about 25%, I think it should be fine.

 

[bhvm]

There is something messy about the specs
"110x 2KW @6000RPM motors."
Do they mean they have 110 motors of 2kW each? Sounds unlikely.

The battery seems to be having 320 cells of 2V each.
That gives 640v At just 14.5 AH. By the math that comes to about 9.28 KW, Not considering Depth of discharge, conversion losses etc. What the heck are they thinking?

My XUV engine generates 140HP, which by pure math (* 0.746) comes too some 100 odd KW. I see buses have engines much larger than XUV. So It must be in 200 to 300 KW range. (I am assuming the Specs are meant to say TWO motors of 110KW each, which comes to 220 KW total power, which sounds reasonable)
How are they supposed to power that thing with just 9 KW of battery?
Is the battery just to last 2~3 kms?

Maybe not the specs but the entire project messed and taxpayer money keeps getting wasted.

aditional math-
If the bus motors consume 220KW per hour, a 9KW battery will last 0.0409 Hours.

 

[carcommentor]

What about the specifications of the electric motors used? In a Hybrid vehicle, the electric motor(s) and the ICE work together, helping each other, in moving the vehicle. Together if they manage to reduce running costs by about 25%, I think it should be fine.

25% of 300Km range means 75 Km is covered by battery (whether continuous or intermittent doesn't matter). For 20,000 Kg bus (including passengers) at average 10,20,30,40kmph speeds, the battery capacity required will be 38.8925, 40.1378, 42.2133, 45.119 kWh.The present 9.28 kWh battery is utterly under powered for that task.
The subsidy of Rs. 1 Crore per vehicle is not justified for the amount of pollutant these type of hybrids are supposed to reduce. You should also note that in a Series Hybrid ( as against Parallel Hybrid) the diesel engine is merely a generator, it doesn't play any role in drive train. The inefficiencies of diesel ICE, the generator, the converter and the battery all add up, so ultimately, the difference between direct drive diesel and a Hybrid is hardly significant, especially with a low battery capacity.
Moreover, to avoid difficulty and longer time taken for charging Lithium Ion batteries, Hybrids work off the battery only when the SoC is between 30% and 80%, which in practical terms means usable capacity of battery is only 50%. Given all these problems, a larger capacity battery is the need of the hour for truly useful hybrid.

 

[m_sherbet]

25% of 300Km range means 75 Km is covered by battery (whether continuous or intermittent doesn't matter). For 20,000 Kg bus (including passengers) at average 10,20,30,40kmph speeds, the battery capacity required will be 38.8925, 40.1378, 42.2133, 45.119 kWh.The present 9.28 kWh battery is utterly under powered for that task.
The subsidy of Rs. 1 Crore per vehicle is not justified for the amount of pollutant these type of hybrids are supposed to reduce. You should also note that in a Series Hybrid ( as against Parallel Hybrid) the diesel engine is merely a generator, it doesn't play any role in drive train. The inefficiencies of diesel ICE, the generator, the converter and the battery all add up, so ultimately, the difference between direct drive diesel and a Hybrid is hardly significant, especially with a low battery capacity.
Moreover, to avoid difficulty and longer time taken for charging Lithium Ion batteries, Hybrids work off the battery only when the SoC is between 30% and 80%, which in practical terms means usable capacity of battery is only 50%. Given all these problems, a larger capacity battery is the need of the hour for truly useful hybrid.

Thanks for the explanation. I wasn't aware of the working of Series Hybrid, i.e. the ICE being merely an electricity generator and not being used for powering the wheels at any moment.

But then I am getting another curious question in mind. Why would they plonk a 5L Diesel engine in the vehicle just to generate electricity?!!

 

[bhvm]

It defies my logic
Diesel to mechanical> Conversion Loss
Mechanical to Generator (Electricity)> Conversion Loss
Generator to Charge Controller (AC to DC)> Conversion Loss
Motor controller to Motor (DC to AC or VFD)> Conversion Loss
Motor to Mechanical Motion>> Conversion Loss

Something isnt right.
Instead they should try to install Twin turbo High compression ratio Diesels and curb pollution using DPF and air cleaners. There will be conversion loss only once or twice. Not to mention Life, Performance and Reliability of diesels.

 

[carcommentor]

....
But then I am getting another curious question in mind. Why would they plonk a 5L Diesel engine in the vehicle just to generate electricity?!!

If that TATA engine's Brake specific fuel consumption (BSFC) is lower than the BSFC of some other TATA's lower capacity engine, then it may be justified. Essentially it would mean the the 5L engine is more efficient than lower capacity engine at particular rev range. However I don't think it is the case here. May be they are planning to increase the battery capacity later[thinking]

It defies my logic
Diesel to mechanical> Conversion Loss
Mechanical to Generator (Electricity)> Conversion Loss
Generator to Charge Controller (AC to DC)> Conversion Loss
Motor controller to Motor (DC to AC or VFD)> Conversion Loss
Motor to Mechanical Motion>> Conversion Loss

Something isnt right.
Instead they should try to install Twin turbo High compression ratio Diesels and curb pollution using DPF and air cleaners. There will be conversion loss only once or twice. Not to mention Life, Performance and Reliability of diesels.

Exactly ! I don't see any sense in the huge subsidy being given for a proportionately meager improvement it efficiency and non-significant change in pollution level.

 

[A.G.]

It defies my logic

Good analysis but let's analyze it step by step.

Diesel to mechanical> Conversion Loss

Un-avoidable in both situations. However, in case of series hybrid, the engine is operating at a fixed speed. Hence the losses are much less as compared to an equivalent engine directly powering the vehicle having constant speed fluctuations. It is easy to design & operate the fixed speed engine at it's maximum efficiency point.

Mechanical to Generator (Electricity)> Conversion Loss
Generator to Charge Controller (AC to DC)> Conversion Loss
Motor controller to Motor (DC to AC or VFD)> Conversion Loss

All the above losses combined would be almost equal to the losses of the manual gearbox with clutch. In case the gearbox is automatic with torque converter, the above losses would surely be less.

Motor to Mechanical Motion>> Conversion Loss

Drive line losses of differential can be avoided in case of Motors with clever software but not incase of diesel engine.

There will be conversion loss only once or twice. Not to mention Life, Performance and Reliability of diesels.

Overall losses in series hybrid would be less than the equivalent diesel powered vehicle. The biggest example of this is the diesel locomotive which for decades has been working on this principal (less the batteries). If there was a fuel saving in directly powering the wheels from engine, I think the locomotives would have had it. Also, the constant speed operation of engine means less wear and tear which is more predictable than the equivalent varying speed diesel engine.

 

[m_sherbet]

Overall losses in series hybrid would be less than the equivalent diesel powered vehicle. The biggest example of this is the diesel locomotive which for decades has been working on this principal (less the batteries). If there was a fuel saving in directly powering the wheels from engine, I think the locomotives would have had it. Also, the constant speed operation of engine means less wear and tear which is more predictable than the equivalent varying speed diesel engine.

After considering the example of the Diesel Locomotives, Series Hybrid suddenly starts making more sense. Thanks for the thorough explanation.

 

[carcommentor]

.......
Overall losses in series hybrid would be less than the equivalent diesel powered vehicle. The biggest example of this is the diesel locomotive which for decades has been working on this principal (less the batteries). If there was a fuel saving in directly powering the wheels from engine, I think the locomotives would have had it. Also, the constant speed operation of engine means less wear and tear which is more predictable than the equivalent varying speed diesel engine.

There is no doubt that a hybrid is more efficient than a pure diesel drive train. The question is , is the difference in efficiency significant ? The answer is a definite no for a small capacity battery. When the battery capacity is low, the diesel engine runs continually (as against continuously ) negating any advantage bestowed by the electric drive train. It is myth that the diesel engine in a Series hybrid runs at a constant speed. Every time the vehicle stops, the diesel engine is stopped and started again after the SoC of battery falls below a predetermined level. With a smaller battery, the frequency of starting and stopping of diesel engine is very high. It should be noted that even under normal operation, the diesel engine in series hybrid runs in a range of rpm. The rpm is not constant. The rpm range is in the lowest brake specific fuel consumption (BSFC) ‘island’ which is typically between 1500 to 4,700 rpm (Black area in the image)

Moreover, the more the number of components in a system, the lesser will be the efficiency. Eg If we take each component efficiency as 45%, 48%,80% and 80%, the total efficiency of the system will be 45%*48%*80%*80% = 13.82% only. Thus the more the components in the system, the more will be its inefficiency which is the case in a series hybrid.
Considering all these, is the series hybrid worth Rs.1 Crore subsidy ? definitely No!.