Showing posts with label Power Management. Show all posts
Showing posts with label Power Management. Show all posts

Tuesday, 22 April 2014

Ultra Capacitors- New Efficiency for Power Train !!!

Electric and hybrid vehicles have been under development for as long as anyone can
remember, but have so far failed to become widely adopted. There have been some
fundamental problems of energy storage and delivery that have yet to be successfully
and cost-effectively overcome. Many of these issues can be traced to the limitations of
batteries – heavy, large in size, with a limited charging rate and potentially high
maintenance.


System designs can take advantage of the power of ultra capacitors to conserve energy
by allowing the engine to stop while the vehicle is not moving and then to be restarted
nearly instantly on tip in of the throttle. The design also allows regenerative braking
energy to be captured thereby significantly increasing efficiency and reducing pollution.
The use of engine start/stop and regenerative braking has been estimated to produce
between 7 and 15% increased fuel efficiency while reducing pollution by an even greater
percentage.

Announced programs for integrating ultra capacitors into vehicle power trains include big
names such as BMW, VW, Honda, Nissan and Toyota, among st many others. These
vehicles run the gamut from concept to production-intent, and include systems for hybrid
trucks, buses, and passenger vehicles are underway.



Problems with hybrid vehicles 

 Batteries have difficulty functioning in cold weather. 
 Batteries require a sophisticated charge equalization management. 
 Batteries have limited cycle life under extreme conditions, which results in high 
cost replacement throughout the life of the vehicle. A new battery has to be 
purchased and installed; the old battery has to be removed and disposed. Battery 
disposal can be problematic unless the manufacturer has a recycling program. 
 Batteries are limited in their ability to capture and provide bursts of high power 
during short duration events such as acceleration and regenerative braking. This 
high power limitation reduces the efficiency of the hybrid electric drive system 
design. 


What is an ultra capacitor? 
Ultra capacitors are based on an electric double layer technology that has been 
understood for over a hundred years, but only available for commercial applications for 
about ten years. 


What are the advantages of ultra capacitors as compared to batteries? 

 They function well in cold weather, down to –40° Celsius, whereas without heating, 
batteries do not operate well below 0° degrees Celsius. 
 They are extremely safe because a pack with equalization is discharged over night. 
 They have a long life cycle, basically built to last the time of the machine into 
which they are incorporated. This means that they are maintenance-free which 
ultimately results in costs-savings. This is particularly important for applications 
where life-cycle cost is of high value, such as embedded power modules, hybrid 
buses and trucks. 
 They are more efficient than batteries; 84-95% as compared to an average of 
below 70% for batteries in this application. 
 They are very environmentally friendly as they are 70% recyclable and do not 
include any heavy metals which are detrimental to the environment. 
 Ultra capacitors offer up to ten times the power of batteries, which plays an 
important role in boosting the acceleration of a vehicle. 


Detailed Case Study of Maxwell Technologies.





Saturday, 19 April 2014

Transforming The Smart Grid..!

Represents the future of Electrical Generation and Distribution Infrastructure. Its paradigm for the class of technology being designed to join forces and modernize our entire energy industry.




A smart grid is a modernized electrical grid that uses analog or digital information and communications technology to gather and act on information such as information about the behavior of suppliers and consumers, in an automated fashion to improve the efficiency, reliability, economics, and sustainability of the production and distribution of electricity.

Imagine a country with no lad shedding, power cuts or blackouts. A new era of reliable and efficient electricity supply is what the smart grid concept promises. Integrating modern digital electronics technologies into the electrical power grid enables the utility to detect, monitor and respond digitally to any changes, thus making it a smarter version of the grid and earning it the name.
Implementing the smart grid concept, will arm the grid with a plethora of sensors, controllers, communication equipment and new technology that enables the grid to be fully automated-enabling it to promptly respond to any incidents in the grid.

How Smart Grid Responds To an Outrage ?

When a disturbance in the grid is initiated, the sensing and monitoring mechanism of the grid detects the cause of the outrage and enables the grid to take measures to quarantine it so it does not affect the rest of the grid. In the quarantined grid, the technology begins working on recovering electricity distribution to the critical services first—providing power to hospitals, police institutions, communications, etc. It will also loop in consumer-controlled power-generation sources when the utility is unable to provide enough power, thus fostering energy trade within the community as well.



Even smarter meters. 


Smart meters are not only limited to measurement, but also play an integral part in deriving the quality of power. “An energy audit meter not only measures the power on a relative parameter, but also measures its quality,” explains A.V. Srinivasan, area manager—south, M.B. Control and Systems Pvt Ltd. He further explains that smart audit meters analyse the power by decoding parameters such as harmonics, power factor and so on.The newer meters not only monitor and provide data to services connected to it but also provide control over the network to designated control centers. With these meters, actions such as overshooting your maximum demand (MD) control or introducing harmonics into the grid will trigger a response from the control center directly to your meter (which is now more of a controller). In smart meter chips, metro-logy is an analogue function where we accurately detect energy across a wide current range. “Integrating multiple analogue functions into one chip is a tremendously difficult task because it involves merging functions that were originally optimised in different process geometries. Ultimately, the biggest challenge is in making the performance of analogue functions similar or better,” says David Andeen, segment manager—smart grid, Maxim Integrated. 

One indigenous example of this technology is in the MREV e2o electric vehicle manufactured by Mahindra Reva Electric Vehicles Pvt Ltd. Stated as Car2Home technology, it allows to power your home by using a car’s power during times of need. An on-board computer smartly regulates the power supplied to your home, and a full battery can ensure that the house is powered up for several hours depending on the load. This technology is complemented by the Sun2Car technology, in which a 10 sq m solar panel is set up to provide sufficient energy to power your car.


Evolving communication standards. 


One of the challenges in this area is the lack of a standard protocol for communication. “Various state utilities are experimenting in a different manner, for instance Maharashtra has looked at Zigbee for AMR-related data collection,” explains Thakurdesai. “The current focus is on powerline communication (PLC), where we have defined G3 and we are also implementing additional solutions. We have also partnered with RadioPulse for ZigBee solutions.,” adds Andeen. Syam Madanapalli, CEO and co-founder, iRam Technologies, explains why a smart grid network is best based on IPv6 (the successor to IPv4; the next generation protocols for the Internet) and IEEE 802.15.4 (the wireless standard from IEEE for the Wireless Personal Area Networks (WPANs)). According to him, “Various devices at a given location in the proposed architecture form a mesh using IPv6 and IEEE 802.15.4 and communicate to rest of the smart grid using a border router. These meshes would be replicated throughout the electrical grid and finally connected to utility using appropriate wide area network (WAN) technologies that are commercially available from the telecom operators or ISPs.”




Advanced metering infrastructure (AMI) and distribution automation. 



AMI is being more deeply integrated into the grid, and its projects are increasingly implemented by utilities, particularly for use in distribution automation (DA) applications. AMI networks require robust communications between individual meters and data concentrators. They use either RF mesh or RF star topology, or implement PLC. For example, to implement AMI, an IPv6-based wireless communication module is attached/integrated into the home energy meter. Few hundreds of homes in a given locality can form a mesh and connect to the utility using one-gateway routers. An additional border router can be provided for load balancing and redundancy purpose.




Automated test equipment. 



The current slew of smart-grid test equipment is automated systems that can test all kinds of relays from manufacturers including ABB and Siemens, as well as different kinds of protection such as overcurrent, distance, differential and generator protection. When enquired about an instrument named smart Megger relay tester (SMRT), a senior engineer explained that conventional test equipment was fully manual and, as with any manual labour, there is a certain amount of human error that is introduced. Modern automated equipment takes away human error and also reduces the amount of work that he/she has to put in.


The voltage levels faced whilst testing circuit breakers are very dangerous. “Modern equipment allows you to do dual-ground testing, which enhances safety levels considerably. Conventionally, with both sides grounded, you are unable to even make a measurement, but our new solution is so unique in that this can be carried out,” explains Ajay Goyal, managing director, Megger (India).


A switchgear will have electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. V. Narayanan, senior application engineer, Megger (India), says, “To check one switchgear, they needed the help of two to three people in order to test it properly. A new tool targeting this problem is the protection condition analyser. This tool allows to test simultaneously all of the key elements of substation protection systems—including protection relay, circuit breaker, DC system and protection circuitry—even whilst the system is on-load. Once the test is completed, it outputs the results on the display.




Multiphysics simulation. 



The huge engineering project of migrating the electrical grid to a smart grid involves modernising several electrical components. For engineers at ABB Corporate Research Power Technologies in Sweden, multiphysics tools have proved an invaluable tool for modelling the coupled electromagnetic, thermal and fluid phenomena that take place within these systems.




Data modelling and forecasting


This is where all the data gathered by the sensors, smart meters and other equipment are put into use.


Avoid gold plating the electrical grid. 



Unlike how it sounds, ‘gold plating’ is where everything is over-designed to be safe, by going overboard with thresholds and limitations. Without smart technology to optimise the operation of the power network, gold-plating has been a common approach to ensure that the network is not going to melt during abnormal events.


One of the approaches to overcome gold-plating is the dynamic rating of equipment. This can be applied to overhead lines, underground cables, transformers, etc.

“A recently developed, groundbreaking technology is a 3D model of the electricity network which provides numerous applications including modelling and forecasting applications. An aeroplane loaded with sensors is flown over the network, where it gathers Lidar data point and other relevant data—such as temperature, wind speed, electromagnetic field, heatmaps, etc. An algorithm is run over the Lidar data to automatically extract the utility’s assets, resulting into a 3D model and exact position of the utility’s assets and nearby environment such as trees,” explains Diethelm.

Is an automated power grid secure?


In addition to terrorist activities, natural disasters and ageing equipment can also bring down the electrical grid. Cumulative smart-grid cyber security investment from 2011 to 2018 will total $14 billion, forecasts Pike Research.


“This requires a better emergency management system with appropriate electronic access control and video surveillance to mitigate problems. The system should also be able to isolate problems and restore electrical services as quickly as possible when disaster happens,” says Madanapalli. The existing SCADA systems are more prone to cyber attacks as the utilities start using more and more computer-based applications without an end-to-end design for the smart grid implementation.