Intelligent Systems for Improved Failure Diagnosis and Reliability in Distribution Systems
* This paper has been rephrased by Abid Jamal, click here to read original one
Abstract—in smart Grid Technology Systems Reliability is the very important term to reduce the graph of sudden electricity outages for a long time which leads to affect the country and customers thereby we need to improve the reliability and quality of the system to overcome this problem. There are many technologies and research papers published in the world to improve the reliability & efficiency of the systems. One of technology is automated switching relays to restore the services after fault and error detected to make the system reliable but these technologies are not working perfectly still there is some hidden issues presents in the systems. if electricity outage occurs in some area the job of automated switching relay is to shift the existing load of a faulted feeder of that area to the next feeder but it doesn’t care about that is next feeder is healthy, have an ability to capable to allow that power flow. The theme of this research paper is to locate the error first and alert the utility provider before occurrence of Fault, the requirements for this job is very high but in 21st century nothing is impossible in this paper distribution fault anticipation (DFA) algorithms and processing analysis is used with some examples to detect the failure to improve the Reliability and quality of the existing smart grid systems.
Keywords—Systems faults; Error occurrence; distribution fault anticipation; Systems Reliability; Restoration; Electricity outages; Failures; provider awareness; Hot clamps.
Smart Grid Technology will allow two ways communication between customers and utility provider but it’s not an easy job if we do this in practice. The first priority of every system is Reliability that how to make the system reliable and improved its efficiency. Electricity outages and blackout will lead a country economy to a dead level every country wants to invest more and more to improve the efficiency of the system to overcome the sudden outages and blackout problems. The present system using some technologies like (Fuses, Re-closers, Automated Relay switching, Tie re-closers) to overcome this problem. There is no such way to inform the utility provider after the fault and damages have occurred and it has been experienced by appliances, apparatus, and equipment this will lead a system or an area into the black zone.
Now in the 21st century still Distribution provider have no proper system to located and detect the error before the occurrence of a fault and serious damages have been occurring.
The authors are with the Department of Electronic Engineering,
Maju University, Mee143015 (e-mail: Abid@electronicslovers.com;
Author website: www.Electroincslovers.com
Utility distribution system provider searching manually to locate the affected area to identify fault or waiting for the customer, some time customers help out the distribution system provider e.g. customer call to utility provider distribution system that near our home cable or Fuse is burn out please come quickly and repair it the operator note the right address and send maintenance Engineer to that area to repair and restore the services.
Need To add the automatic monitoring intelligent system at distribution system to improve service reliability. After a continuous struggle and hard work, the power system Laboratory comes with new and conceptual idea under the sponsorship of Electric Power Research Institute. The concept of PRI is that failure can be diagnosis and error can be detected & locate on distribution system by a sophisticated analysis of waveform through existing (CTs) current transformers & PTs (potential transformers) before serious damages have occurred. They record hundreds of waveforms in a database from some failing Distribution equipment this enables the operator to monitor the Real-time Data collection waveforms coming back from distribution feeders to detect and locate the fault on the basis of these waveforms on Real time. The name of this powerful tool is Distribution Fault Anticipation (DFA) systems, monitoring continuously and sends alert warnings, report of some failure to operators and provider it will aware the operator that something is going to be failing or failed before some serious damages or blackout occur.
The operators will receive Thousands of waveform the staff and engineers will judge very carefully those waveforms the waveform with low current amplitude may remain same for weeks but some time due to lose joints this amplitude change its value e.g. from 5A to 200A again to its normal amplitude of 5A the changing of amplitude shows that something is lost or not tightly joint on the distribution system this may cause to a flickering and burnout.
Fig.1. Existing Power Flow Topology in SGT without DFA Generation point 2 (Diesel Generator, Wind Turbine, Hydro)
II. Re-Routing PROBLEMS
The existing Re-Routing & self-healing system of smart grid technology is not efficient in Fig.1 there is two Generation points which further connected with two substations to provide electricity to the end user customers why we are moving towards DFA the reason is that if the link between Substation 2 and the End users customers 2 are burned out or cut down or any other legal incident may occur so the substation 2 will directly inform the substation 1 and will shift their existing load to Substation 1 through Automated switching Relay but the substation 1 don’t know that how much power SS1is receiving from generation point and is it capable or healthy to allow this power flow .
Generation point 1 output = 350 Mw
Generation point 2 output = 120~250 Mw (Solar Energy Vary)
If the connection Down or fault may occur so our mission is to provide reliability to the systems for doing this the SS2 will shift its 250MW load to SS1 Through automated switching relay now its job of SS1 to Handle these load and provide Electricity to the End customers in short time it is good method but the disadvantage of this method is now SS1 will have to deliver 600MW power flow to the end users customers1 and End users customers 2 to allow this technology for efficiency and reliability The SS1 and SS2 will have the ability to Deliver more power if sudden electricity outage occurs the new Formulation of the system will look like this
Generation Point 2 will Generate =600Mw Not 250MW
Both Generation points may be Healthy to capable this power flow if sudden outage may occur.
Fig.2. Power supply line burns out or cut due to some reasons the SS2 shift their existing Load to SS1 through ASR.
Must be a communication path between SS1 & SS2 they will communicate with each other if sudden damages occur they will inform each other to turn on and off the load. The ASR (Automated switching Relay) is an electromagnetic switch work as like a button to turn on and off some loads, connections, paths etc The Second and Major Disadvantage of this system is that there is no proper way to locate and detect the error the operators are waiting for the customers or searching manually to locate the faulted area it’s too hard and not efficient way the Third disadvantage of this system is complexity and cost if we use this technology our system will become complex and will not remain cost-effective.
III. Advancement in technology
Electric power Research Institute (EPRI) with the help of sponsors working on Diagnosis failure and monitoring for more than decades the big milestone in the implementation of DFA system is that how to analyze these electric waveforms we are not talking about one feeder or one generation point it’s about the state. Using DFA algorithm the utility provider can easily detect and locate the error using electric waveforms the operators and engineers will monitoring these waves continuously so they will be able to notice each wave accordingly it needs strict monitoring with a sensitive alarm system to inform the operators that something is failed or going to be failing.
Figure.3 Using DFA& Digital signal processing techniques to analyze the Electric waveforms for one Feeder.
Y-axis on Fig.3 shows amplitude of the current (A) This amplitude can vary from 0~40A on normal condition by using DFA algorithm we can detect the faulted area using this graph and digital signal processing techniques when amplitude goes high as we can see on fig the amplitude goes upward to 89A a sudden surge occurred on Electric waveform this may alert the operator by Turn on Alarm system most of the time the reason behind this sudden surge occurs is due to lose joints so now its duty of the Distribution provider to reach to correct destination and correct the fault before outage occurred. The research shows that Lose joints is 86% cause of Blackout so why not to measure and diagnose these electric waveforms whenever the current peak goes high it means there is some lose joint present in the distribution system it works simply like a short circuit if we look over the Ohm law it tells us that I=V/R if we connect the two wires direct the resistance become~0 which gives us the infinite current it means something is short or sparking so our theme and job is to look over this first not later.
Causes of Power Failures & Power Outages
Customer call > 1: 15 Dec 2009 4:30 PM
That 30A fuse Blown please come to our area and Repair it operator send maintenance team to that area and Replace 30A fuse by inserting a new one and leave without finding and knowing the cause.
Customer call> 2: 17 Dec 2009 6:57 PM
That light is flickering in Distribution power line please come and repairs it they come and repair without knowing the cause.
IV. ILLUSTRATIVE EXAMPLES
This section will describe some real-life examples that will show the main reasons which degrade our reliability performance.
Incipient Failure of Hot-Line Clamp
Distribution power line that carry a high Load current which develop a hot spot at the start this point producing a little power dissipation in form of heat but no one notice that little hotspot area at some cases Customer call to Utility provider that near our home Some sparking phenomena is occurring after every 3 seconds please come and repair at OR after some time that Hot Spot may cause to sparking, Flickering of lights, Fire burn out and Degrade Reliability and performance.
Fig.4 Hotline failure Example
Job of Generation point is to generate Electricity to meet the required demand of the load after this through Power distribution lines it transfers these Sinusoidal waves to a substation now in Fig.4 there is a Fuse connected between substation and Hotline clamp for protection the T1 transformer 1 and T2 transformer to just Step down the High voltage in to usable level like 11kv to 220v but here we can see there is some Joint Hotline clamp which connecting These two transformers most of the time this clamp start sparking heat due to Lose joint of conductor and jaw of the clamper. Fuse work is to cut down the power supply if load current exceeds the given current level but it’s not a solution we need to detect and locate the error using DFA algorithm rather then cut the supply and shift the load to a next substation. On 26th November 2009, recorded a similar activity of Electric waveforms during a day and after a day the change in amplitude of the electric wave was abnormal but utility provider doesn’t know about that at last they found the issue on 14 December 2009 and replaced the clamp but this issue and fault was detected months ago by using DFA algorithm.
Fig.5 current measured at a substation during the incipient hot-line clamp.
In Fig.5 the Substation can provide a maximum of 60~61A steady load current to the End-user customer but if we look over at the graph that for a short interval of time it can change its amplitude and moved from 60A to 70A we already know the steady state load current maximum threshold so from where the Rise of 10A come so this electric waveform trying to show us that there is some Lose joint, hot clamp present in the distribution line which compel the electric wave to change its amplitude so an Electric waveform analysis engineer will look after this and send immediately a Maintenance team to that area to replace the clamp by new one before Outage occur whenever it produces sparks the Amplitude of the Electric waveform will go High now we can easily detect and locate the error first before electricity outage occur. From this example we got that lose a joint and hot spot at clamp is the big cause of electricity outage and blackout.
Most of The time utility provider waits for the customer call
Event 1: 13 December 2009, 4:50 AM: Utility provider received outage call from customer they send maintenance team to that area correspondingly they found that 30 Ampere Fuse is blown out they replaced the fuse with new one but the team were unable to identify the cause of the fuse operation that why that fuse is blown away is there any problem in clamp, Distribution line. The services restored to that area at 5:50 Am so total one-hour outage is equal to a big loss.
Event 2: 14 December 2009, 5:58 PM: The utility provider received another call from customer that near our Home there is sparking and continuous flickering at transformer the operator sent maintenance team to that area they replace the transformer by new one and restored the services but when they test the faulted transformer in Lab they did not found any major problem they replaced the inside fuse of the transformer after replacing the fuse transformer works good and become healthy then where were the problem the problem was in “HOT CLAMPS” The sparking and Flickering was due to Hot clamps and loose joints.
Event 3: 14 December 2009, 7:44 PM: Same customer call again and reported about sparking and flickering of lights But this time they observed and found that problem as in clamp they simply replace the faulted clamp by a new one.
The entire event above causes by the hot clamps or lose joints some time customer does not call on time or so this hot clamp is the big reason for Fire.
By using DFA algorithm on these three events it will inform us before three weeks that there is a problem in that clamp near Transformer x or y by observing the Electric waveform.
DFA algorithms needs high attention that needs someone to know the analysis of Electric waveform and know the Difference between Normal and Abnormal wave the Waveform analysis engineer will receive Thousands of waves now he needs to be more careful and these large number of waveforms need a high data centre to analyze and store we need to add some automation in DFA because the engineer will receive thousands of waveforms at one time now it’s out of human control they need to automated firs store the Electric waveform analyze it.
Many Technologies deployed just try to make the system reliable by Rerouting the power to reduce the duration of outage to give comfort and stability to the customer they simply shift the Existing load to another substation when fault occurs in the distribution lines But after a long research author found that why not to first locate and detect the error before occurring of outage phenomena they found a New algorithm called DFA Distribution Fault Anticipation by using DFA we can detect and locate the fault. The fault can be detected in distribution lines by analyzing the behavior of Electric waveform now it’s an easy and sophisticated way to reduce the number of outages without waiting for the customer call. The number of electric waveform volume will be in thousands so It needs a large data centre to store each and every wave first and then analyze it the system must be protective will be on focus with high consideration the data size would be doubled if we analyzing the electric waveforms of two Feeder so by increasing the Number of feeders would be directly Proportional to the number of electric waveforms but by using automated process we can reduce the Data size of electric waveforms and after great effort of Author this system is deployed in multiple utility host providers
The Author gratefully acknowledges the support of Muhammad Ali Jinnah University Islamabad campus and especially appreciates the support of Dr Sajjad Hussain the author gratefully to the Electronic Engineering Department and those who helped the author.
Abid Jamal Mee143015 Received the B.S. Degree in Electronics & Communication in September 2014, Currently Doing M.s Electronic Engineering at Muhammad Ali Jinnah University 2014~2016
He is the Creator of the Website www.Electronicslovers.com He got the A grade in Electronic & circuits MIT online certificate He has done many projects using Different kinds of Microcontrollers Now he is currently Doing research on How to extend the Battery life of smart Electric vehicle.