EVHUB Forum updates

What is the difference between 40Cr steel and EN8 Steel and which is better?  Created on May 12 2010 at 07:00:35 AM by murali	1
Useful links in Brushless DC Drives Created on May 12 2010 at 06:15:38 AM by Admin	1
Useful links in Electric Hybrid Vehicles  Created on May 12 2010 at 06:15:04 AM by Admin	2
Dealers in Delhi/NCR Created on May 11 2010 at 03:52:23 PM by Payal Mehra	2
how to maintain the electric vehicle battery Created on May 11 2010 at 03:02:48 PM by selvan	2
how to convert cylinder capacity(cc) to power( watts) Created on May 11 2010 at 02:36:56 PM by selvan	2
What do you prefer? Electric Bike or Petrol Bike? and Why? Created on May 11 2010 at 02:30:43 AM by murali	3
Electric Byke shops in chennai Created on May 10 2010 at 04:37:56 PM by Gowri Shankara Rao Uriti	3
Encouraging schemes to switch over to electrical bykes Created on May 10 2010 at 04:34:37 PM by Gowri Shankara Rao Uriti	3
Electric Vehicles Vs Petrol Vehicles Created on May 9 2010 at 04:25:22 AM by sireesha	4

Paper_on_PM_motor_by_Ashish_D

Permanent Magnet Motors Introduction and Trends

 

Introduction of Author:

Ashish Deshpande has been working in the domain of electrical motor design and air conditioning for last 11years. His area of interest is Interior Permanent Magnet motor design and development.  He is continuing his master degree from Bharati Vidyapeeth, Pune. This article is related to his dissertation work which is guided by Prof.Mrs. S.S. More. His dissertation topic is Design of Permanent Magnet Motor (PMSM) for Air Conditioning Compressor by Optimum Utilization of Induction Motor Manufacturing Set Up. You can contact him on ashishonmail@rediffmail.com 

 

 

Induction motor is preferred choice of manufacturer and customer primarily due its robustness, easy manufacturing, and low maintenance. But is this the most efficient motor? Answer is obviously no. Efficiency is function of losses, so let us revisit the Induction Motor losses as shown in figure1. Now if compare these losses with permanent magnet (PM) motor, we would notice that there is rotor copper loss which is almost 15 to 20% of overall losses.

As these losses goes down the cooling requirement of motor can be     reduced.

 

Figure1 : Losses Comparison of IM and PMSM

 

PM motor offers following benefits over Induction Motor,

· No rotor copper losses

· Cooling of the motor only for the stator copper and iron loses, cooling requirements goes down

· Different size/ volume and arrangements of magnets on the rotor will lead variety of desired characteristics.

· Higher efficiency because of fewer losses.

· Compact high density magnets can reduce the overall size of motor

 

The indicative comparison of various parameters is covered in Conclusion.

 

If we compare various motor technologies as against design, performance and manufacturing parameters, following table helps to select the appropriate technology. The scale between Excellent and Positive is larger to magnify the difference in various technologies.

 

Excellent: 10

Positive: 3

Weak: 1

 

Table 1: Motor Technology Comparison

Parameters	IM	PMSM	BLDC	Variable SRM
Efficiency	3	10	10	3
Noise (low)	3	10	3	10
Converter Complexity	1	1	3	1
Power Density	1	10	10	3
Power Factor	3	10	10	3
Torque Ripple Low Speed	1	10	3	1
Starting	3	3	3	3
Manufacturing	3	3	3	1
Total Score	18	57	45	25

IM: Induction Motor

PMSM: Permanent Magnet Synchronous Motor (or BLAC)

BLDC: Brushless DC (Uses Permanent magnet)

SRM: Switched Reluctance Motor

 

Above comparison clearly shows that PMSM will be the future technology.

 

What is Difference between PMSM and BLDC motor?

There is confusion or misconception about Brushless DC and Permanent Magnet AC. Many people think that BLDC (Brushless DC Motor) is permanent magnet motor. But there are two separate technologies available, BLDC and BLAC (Brushless AC Motor). BLAC motor is nothing but PMSM.

 

The significant difference in operation of these two motors is the stator winding design and in turn back EMF generated.

Following are several terms interchangeably used in BLDC and BLAC literature.

· BLDC: Square wave motor, Trapezoidal wave motor

· BLAC: Permanent Magnet Synchronous Motor (PMSM), Sinwave motor

 

The BLDC needs separate manufacturing set up for stator to develop BLDC motor for Induction Motor manufacturer. Whereas the BLAC (PMSM) motor can utilize the existing induction stator set up including winding machines.

Figure 2 shows the winding distribution for BLDC and BLAC.

BLAC (or  PMSM) stator is similar to Induction motor stator and uses distributed winding. Whereas BLDC motor uses concentrated winding unlike Induction Motor. So BLAC stator can easily built on Induction motor manufacturing set up, but for BLDC motor new manufacturing set up is required. 

 

Figure 2: BLDC and BLAC (PMSM) Stator Winding

 

In case of BLDC motor, the winding is energized in normally 60 electrical degrees. This generates pulsation in torque. So BLDC motors are prone to vibrate more and needs attention if the application is sensitive to sound and vibration. The advantage of BLDC motor is simple construction and less expensive controller. BLDC stator can be easily build on DC motor manufacturing set up. In case of PMSM there are very less torque pulsation and sound quality and vibration are at par with BLDC and IM. But PMSM need complex field oriented controller and start up algorithm making it bit expensive than BLDC.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Depending winding type, rotor mounting method, back EMF waveform,

Permanent Magnet motor can be classified as shown in figure 3,

 

 

 

Figure 3: Classification of Permanent magnet motor

 

Both BLDC and BLAC have got the permanent magnet on rotor, various rotor configurations are available depending on magnet mounting on rotor. Two major rotor configurations as shown below (figure 4),

 

Figure 4: Permanent magnet rotor configuration

BLAC (PMSM) with Buried Magnet or interior magnet rotor is most popular configuration to replace Induction Motor. The Interior magnet rotor makes motor to operate in field weakening region or above base speed as shown in figure 5.

 

  

Figure 5: Operation Range of IPM motor

 

Spoke type or C type interior designs are manufacturing friendly.

Sensors are used for sensing rotor position to drive current in stator winding.  Resolvers, Hall sensors, optical encoders are few of the sensors available with these motors. Following figure 6 shows the typical BLDC motor block diagram.

 

 

 

 

 

 

 

 

 

 

 

Figure 6: Block Diagram of Typical BLDC Motor with Sensor. 

 

In certain applications sensors can not be used, like hermetic motor for air conditioning compressor. So there are sensorless PMSM motors which estimate the rotor position and voltages from mathematical model of motor. There is ready made solution from IC manufacturers for PMSM. In India also there are few IC companies who offer this technology from there counterparts in US or Japan.

 

 

 

Trends in Motor and Drives Technology

Following figure shows the overall technology trend in motor-drive segment.

 

 

 

 

 

 

 

 

 

 

Figure 7: Motor and Drives Technology Trend

 

With the development of MOSFET and IGBT switches, the power electronics

widened the applications for high current and voltage applications. Especially

Inverters technology developed rapidly and now most efficient and sophisticated

Space Vector PWM technique is available.

 

In case of motor technology, Induction motor posed lot of challenges to new

technologies due to its simplicity, low maintenance and cost. For next couple of years Induction motor may be back bone for most of the electromechanical energy conversion applications. But with energy crisis the need of efficient technology is posing great threat to Induction Motor. PM motor is primarily developed from demanding energy efficiency requirements. Also BLAC (PMSM) is widely accepted technology for Hybrid Electric Vehicles, so the development and research is on rampage. Following is electric machine technology trend.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 8: Motor Technology Trend

Conclusion:

 

As Interior Permanent magnet (IPM) rotor configuration allow the field weakening operation, it is considered to be Induction Motor replacement. Also IPM offers better protection against demagnetization of magnets due to stator magnetic field. It provided barriers to stator flux and avoid demagnetization. So IPM is proffered configuration.

 

Surface mount PM rotor configurations is suitable where field weakening is not required and motor runs at constant speed. The magnets are glued over the rotor surface, hence there is restriction on rpm for surface mount PM rotor configuration.

 

Instead of simple PWM, Space Vector PWM controllers are efficient and hence it is preferred.  To reduce switching losses and hysteresis losses, the number of poles needs to selected for Permanent magnet motor.

 

As PMSM or BLAC develops less torque pulsation, it is used in the applications where noise and vibrations need to match with Induction motor. The BLDC can be used where there is not stringent requirement on noise and vibration. PMSM needs field oriented control and start up algorithm so its controller is expensive than BLDC. Depending customer specification BLDC or BLAC can be selected.

 

For induction motor manufacturers, it easy to switch to BLAC or PMSM type motor as stator manufacturing facility can be utilized as it is. BLAC is getting popular for Electric Vehicle application.

 

With reference to Induction Motor, PMSM motor parameters are compared in following charts. Volume and weight of equivalent will be reduced by 20 to 25%.

Figure 7: Volume of IM and PMSM

 

Figure 8: Weight of IM and PMSM

 

Figure 9: Efficiency of IM and PMSM

 

Above comparison is for rating 5hp and above. Following chart shows IM and PMSM efficiency comparison for 5hp and below ratings.

 

Figure 10: Efficiency of IM and PMSM (5HP and below rating)

 

These performance and dimensional parameters are studied and compared from

various motor manufacturers catalogue and brochures. This comparison is

indicative and sets expectations from PM motor. User may get more benefits by using PM motor as indications are based on conservative data. 

 

PMSM technology provides good opportunity to reduce energy

Consumption and get more star ratings developed by BEE for many appliances and applications. The challenges to build permanent magnet rotor is also reducing as many Chinese suppliers are providing sophisticated permanent magnet rotor manufacturing set up. Even though initial cost of PM motor will be high, the pay back period will be less than IM. PM motor can be future back bone for many electromechanical conversion applications.

.

Note from EVHUB.BIZ 

 This article was published in http://www.evhub.biz for sharing the importance of Permanent magnet motors. Permanent magnet motors are being used in various electric vehicles - 2 wheelers, 3 wheelers and heavy vehicles due to the advantages explained in the above article. 

 

 

Introduction To Hybrid Electric Vehicle And Key Challenges

Due to increase in fuel cost and high efficiency demand from market, electric vehicle development is ramped up. Toyota launched its first Hybrid Electric Vehicle (HEV) and it is commercially available across the world.  This article focuses on introduction of HEV and some of its design challenges in electrical system perspective. It also covers how simulation technology is going to play important role in the product (HEV) development.

Inverter, battery, converter and motor are the major additional or new components in the vehicle to make if HEV or EV. Here the battery is also referred as additional component as it would battery pack unlikesingle battery in existing conventional vehicle. Refer figure1, the major components and its likely positions are indicated in the vehicle.

Read full article @ http://www.evhub.in/content/introduction-to-hybrid-electric-vehicle-and-key-challenges/

Permanent Magnet Motors Introduction And Trends

Induction motor is preferred choice of manufacturer and customer primarily due its robustness, easy manufacturing, and low maintenance. But is this the most efficient motor? Answer is obviously no. Efficiency is function of losses, so let us revisit the Induction Motor losses as shown in figure1. Now if compare these losses with permanent magnet (PM)motor, we would notice that there is rotor copper loss which is almost 15 to 20% of overall losses.

As these losses goes down the cooling requirement of motor can be     reduced.

Read full article @ http://www.evhub.in/content/permanent-magnet-motors-introduction-and-trends/

EVHUB.IN 's stall in Bangalore International Auto Expo 2010 as EV media ...

Video Of EVHUB's Stall In Bangalore International Auto Expo 2010

EVHUB's Stall in Bangalore International Auto Expo 2010 as Electric Vehicle media partner to the event. 


Go the video - http://www.evhub.in/content/video-of-evhubs-stall-in-bangalore-international-auto-expo-2010/

Battery Technology Used In EVs

A battery is the most expensive and least environmentally friendly component of an electric car. It is a real pain - a hurdle that keeps the electric motoring from development. Using the knowledge we posses, we cannot make an EC travel further than 120 miles between recharges.

With such a low range it is and remains limited by city borders not giving us the real mobility and flexibility. Is there a chance we could come up with a new electric car battery that gives us a better range? Let's first look at the known and available options.

1.    Lead-Acid Batteries

Although Alessandro Volta invented a battery in 1800, it was 1859 when a lead-acid prototype was created by Gaston Plante. These batteries are robust, tolerant to abuse, tried and tested and because of their low cost.

Ø  For higher power applications with intermittent loads however, Lead acid batteries are generally too big and heavy and they suffer from a shorter cycle life and typical usable power down to only 50% Depth of Discharge (DOD). Despite these shortcomings Lead acid batteries are still being specified for Power Net applications (36 Volts 2 kWh capacity) because of the cost, but this is probably the limit of their applicability and NiMH and Li-Ion batteries are making inroads into this market.

Ø  Lead-acid batteries are composed of a Lead-dioxide cathode, a sponge metallic Lead anode and a Sulphuric acid solution electrolyte. This heavy metal element makes them toxic and improper disposal can be hazardous to the environment.
The cell voltage is 2 Volts 

read full article @ http://www.evhub.in/content/battery-technology-used-in-evs/

Introduction To Electric Motors And BLDC Motors

Presentation on " Introduction To Electric Motors And BLDC Motors " 


http://www.evhub.in/content/introduction-to-electric-motors-and-bldc-motors/

Presentations on Electric Vehicles

Please check the presentations on electric vehicles

Understanding Electric hybrid vehicles - http://www.evhub.in/content/presentation-on-electric-hybrid-vehicles/

Electric Bikes in India - http://www.evhub.in/content/electric-bikes-in-india---presentation/

Article on " Battery Operated Vehicle " in http://www.evhub.in

A battery operated electric vehicle (BEV) uses electricity stored in its battery pack to power an electric motor that turns its wheels. The battery pack is often recharged by connecting or “plugging” it into a wall socket or other electrical source, such as a solar panel. 

Because a BEV uses electricity as a fuel, there are no emissions out of its tailpipe. In fact, it does not even have a tailpipe!

Moreover, it is very friendly on pocket to recharge a BEV. The development of BEVs has made a significant contribution to battery research and to the advancement of electric motors and power electronics used in both hybrid electric and fuel cell vehicles. 

Read full article @ http://www.evhub.in/content/battery-operated-vehicle/

EVHUB Forum updates - Discuss here!

TOPIC TITLE	# of POSTS
Useful links in Brushless DC Drives Created on May 12 2010 at 06:15:38 AM by Admin	1
Useful links in Electric Hybrid Vehicles  Created on May 12 2010 at 06:15:04 AM by Admin	1
Dealers in Delhi/NCR Created on May 11 2010 at 03:52:23 PM by Payal Mehra	1
sample topic Created on May 11 2010 at 03:52:21 PM by mathi1	2
how to maintain the electric vehicle battery Created on May 11 2010 at 03:02:48 PM by selvan	1
how to convert cylinder capacity(cc) to power( watts) Created on May 11 2010 at 02:36:56 PM by selvan	1
What do you prefer? Electric Bike or Petrol Bike? and Why? Created on May 11 2010 at 02:30:43 AM by murali	3
Electric Byke shops in chennai Created on May 10 2010 at 04:37:56 PM by Gowri Shankara Rao Uriti	3
Encouraging schemes to switch over to electrical bykes Created on May 10 2010 at 04:34:37 PM by Gowri Shankara Rao Uriti	2
Electric Vehicles Vs Petrol Vehicles Created on May 9 2010 at 04:25:22 AM by sireesha	4

EVHUB Forum updates

What do you prefer? Electric Bike or Petrol Bike? and Why? Created on May 11 2010 at 02:30:43 AM by murali	1
Electric Byke shops in chennai Created on May 10 2010 at 04:37:56 PM by Gowri Shankara Rao Uriti	1
Encouraging schemes to switch over to electrical bykes Created on May 10 2010 at 04:34:37 PM by Gowri Shankara Rao Uriti	1
Electric Vehicles Vs Petrol Vehicles Created on May 9 2010 at 04:25:22 AM by sireesha	4

The World's Largest Entrepreneurs Conference

Starts:	Friday May 14, 2010, 07:00AM
Ends:	Saturday May 15, 2010, 06:00PM
Event Type:	Conference
Location:	Santa Clara Convention center 5001 Great America Parkway Santa Clara, CA 95054 US

Read full article about this event @ http://www.evhub.in/content/tiecon-2010---the-worlds-largest-entrepreneurs-conference/

EVHUB.IN portal launched - World's first B2B portal exclusively for Electric vehicles

Good News to all EV enthusiasts. Our new portal http://www.evhub.in is launched and online now.

Now you can

1. Register as a person or company - http://www.evhub.in/register-your-company/
2. Discuss and meet people in our forums - http://www.evhub.in/forums/
3. Submit your company profile and display your products online with various B2B features free, paid and premium listing
4. Latest news updates in EV industry
5. Read our informative articles @ http://www.evhub.in/blog/

and many more .....

Happy browsing. If any queries , contact us to mail@evhub.biz

Tour around Bangalore International Auto Expo 2010

Tour around Bangalore International Auto Expo 2010

Click here to see the slide show - http://biae2010.evhub.biz/home/tour-around-bangalore-international-auto-expo-2010

Welcome to EVHUB's Stall A102 @ BIAE2010

Bangalore International Auto Expo 2010 was inaugurated by Honorable Chief minister of Karnataka today. EVHUB.BIZ , Online Portal exclusively for Electric Vehicles displaying its services in stall number A102 at BIAE2010. EVHUB has inaugurated its new portal http://www.evhub.in and the beta version of this page is ready for our visitors now. 

read more @ http://biae2010.evhub.biz/home/bangalore-international-auto-expo-2010-inaugurated

Bangalore International Auto Expo 2010 Inaugurated

Palace Grounds, Bangalore- March, 11th.

 Bangalore International Auto Expo 2010 was inaugurated by Honorable Karnataka Chief Minister Shri B.S.Yediyurappa today. Lighting of the lamp was done by Mr. R.V.Deshpande. The Auto show will be there from March 11th till 15th in Palace grounds. Various Automotive giants like Tata, Ford are participating in this fair.  

EVHUB is the EV Media partner to this expo and exhibiting its services in A102 stall. 

Other companies who are participating are TopGears, Celite Tyre Corporation, Faschingsalzburg GmBH Austria, Onassis Auto limited and many more. 

Stay updated with http://biae2010.evhub.biz for updates on this fair.

Read more @ http://biae2010.evhub.biz/home/bangalore-international-auto-expo-2010-inaugurated

EVHUB.IN domain registered

http://www.evhub.in registered to cater electrical vehicle yellow pages, B2B information of India. This portal is an extension to http://www.evhub.biz portal and now in development stage.

Engineering Expo 2010

Engineering Expo - India’s premier Industrial Trade Fair The success of every exhibition is the response received from its participants and the satisfaction level of its visitors. Engineering Expo since 8 years has been following this vision and has become the preferred investment partner for most companies that desire to grow their business in India. Known as business epicenters of India, states like Maharashtra, Gujarat, Madhya Pradesh and Tamilnadu are fetching new business prospects for the manufacturing industry at large. Engineering Expo provides you the opportunity to tap these new markets. Meet the Real Buyers At Engineering Expo, we are making inroads in small and big towns, educating the SMEs about the latest trends and technological developments shaping up in the engineering segment. Through our extensive reach and strong connect, we are continuously updating them on the latest happenings at the Engineering Expo. This will greatly keep the visitors interest intact and will help them in making buying decisions when they visit the Expo. read full story @ http://www.evhub.biz/news/engineering-expo-2010

Exhibit your products in BIAE2010

Official Electric Vehicle Media partner to

www.biae.in

11 to 15 march -Palace Grounds - Bangalore, India

Click here to visit  www.evhub.biz 

Click here to Exhibit               Click here to Visit