IET-UK International Conference on Information and Communication Technology in Electrical Sciences (ICTES 2007), Dr. M.G.R. University, Chennai, Tamil Nadu, India. Dec. 20-22, 2007. pp.1-7.
DEVELOPMENT OF WEB BASED POWER QUALITY MONITORING SYSTEM FOR HANDLING USER CUSTOM POWER QUALITY QUERY AND AUTO POWER QUALITY MONITORING REPORT NOTIFICATION VIA EMAIL Bansidhar E. Kushare*, Ashok A. Ghatol†, Sumit Kala‡ †
* EED, KKWIEE&R, Nashik India,
[email protected] Dr. Babasaheb Ambedkar Technological University, Lonehere and Vice President of Indian Society for Technical Education, New Delhi, India ‡ Coriolis Technologies, Pune, India
Keywords: Power quality, Monitoring, Harmonics
swell, over-voltage, under-voltages and harmonic distortions [5, 10]. Majority of the equipments used in industries are sensitive to power quality problems. To avoid the malfunction and unnecessary costs it is necessary to install power quality monitoring system to understand the problem and provide cost effective solution [3]. In order to improve electric power quality and energy efficiency, the sources and causes of such disturbance must be known for both supply and demand sides before appropriate corrective or mitigating action can be taken [13]. A constant supervision of power quality allows the user to notify the power distributor about problems with delivered energy. A real time power quality monitoring will help to take some corrective actions such as power factor correction, consumption reduction etc.
Abstract Power quality monitoring has increasing role in deregulated electricity supply market. Various utilities all over the world are collecting power quality data to provide a power quality database as a source of benchmark. In deregulated electricity market utilities will be required to provide reliability and power quality indices. Industrial and commercial customers are increasingly getting affected by poor power quality problems. A real time power quality monitoring will help to take some corrective actions. A web based, near real time power quality monitoring system is necessary to provide such information, both locally and on Nation wide basis to customer. This paper discusses the web based power quality monitoring system. The entire system has been developed on Java technology. The power quality web based system implemented allows user to access the power quality information and provides auto email notification of the custom power quality report to specified user. The other facilities provided are auto plotting of various RMS voltage variation events such as voltage sag and swell on ITIC or user specified curve and facility of trending plot of total harmonic voltage and current distortion. The proposed system will be useful to industrial customers and utilities.
The major problem faced during the power quality monitoring is, analyzing vast volume of power quality data collected. User is required to do labor intensive manual process of trying to identify the required power quality event that has occurred with their characteristics visually through Gigabytes of data. When monitored data of various sites is available the task of identifying the specified power quality event in which user is interested based on objectives becomes tedious. The other problem associated with various power quality equipments is limited storage and in various sites where the disturbing loads form the major portion of total load, the memory capacity of monitor gets over. Once the memory of the monitor is full the system error causes equipment to stop monitoring. To avoid the problem it is necessary to download the data automatically to the server through an Ethernet network. A key feature for analyzing the vast volume of power quality data collected by monitors is to develop suitable algorithm that will be able to automatically detect power quality event as per user query. Ability to automatically detect abnormal variation from normal form existing database will allow operators or user to be notified
1 Introduction Power quality has become important concern for utility, facility managers and consulting engineers in recent years. End user equipments are more sensitive to various power quality problems that arise both on the power supply system and within customer facilities [13]. Poor quality of electric supply is normally caused by power line disturbances such as transients, notches, momentary interruptions, voltage sag and
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automatically through email. A web based, near real time power quality monitoring system will provide such information, both locally and on Nation wide basis to customer. The authors have developed and implemented web based power quality monitoring system which will be useful for the utilities and industrial customers. Web based power quality monitoring system has been presented with result.
9. Availability of web base power quality and reliability indices of various utilities will help the customer to choose the electric supply and utilities to offer differentiated services for customer that have special requirement [7].
3 Overview of Previous Work Related to Web Based Power Quality Monitoring
2 Need for Web Based Power Quality Monitoring System
Reference [8], proposed the methodology for distributed power quality measuring system to monitor a number of power quality indices on every load connected to the point of common coupling. To transmit the measured values to master device that processes them in order to locate the source of unbalance and harmonic distortion and to quantify the effect of such disturbance on power quality. A distributed master slave structure was adopted as the architecture of the measurement system. A slave system was located on each metering section. Each slave system acquires the line voltages and currents in the metering section and determines the RMS value and frequency domain components. The total active power, the apparent power and power factor are then obtained together with generalized THD factor. All measured quantities are averaged on a pre-settable time interval and transmitted to master system through intranet or if necessary through internet.
There is need for permanent power quality monitoring system because of following reasons: 1. With the increasing problems in electrical distribution system, there is a need to have thorough power supply and distribution system monitoring and measurement before a solution is proposed [13]. 2. The well known problem of current harmonics must be monitored on a continuous basis to ensure that, over a time, the incremental addition of loads does not cause excessive heating that can lead to power loss, premature failure of transformer, capacitor etc [13]. 3. Continuous tracing of power consumption and electrical quantities provide useful data for planning future plant expansion and for ensuring that existing and future distribution feeder are adequate [13].
The proposed master system has complete visibility on all measured quantities and indices in different metering sections. The master system can be located away from the PCC, thus allowing for a centralized, remote control of power quality. The master system has therefore the capability of identifying the source producing distortions and quantifying their detrimental effects on the power quality. The master system also logs all values coming from the slave systems for post processing purpose.
4. To detect on continuous basis various symptoms of power quality such as harmonic distortion, voltage dips, interruption, transient etc. The available data will help in taking remedial action under power quality predictive maintenance philosophy before the problem causes any damage to equipment. 5. Extrapolating the available power quality information, predictive analysis can be performed to forecast specific breakdown conditions, like overheating of switch boards, current surges, over voltage, voltage sags and fluctuations or to detect deterioration and PQ degradation. Through early detection it is possible to take corrective action to rectify or retrofit the situation.
A critical point of this architecture is the need to process the data obtained by measurements performed simultaneously by all slave devices. The synchronization proposed was by synchronization of clock of master and slave devices, but is expensive. The measured value of indices was plotted with time. According to reference [8], the analysis of all these indices performed by master unit leads the evaluation of global index that provides on the test network considered, correct information on the location of sources producing distortion and measurement of their effect on power quality.
6. Availability of data base related to power quality and reliability indices to electricity regulator and customers is one of the requirements in deregulated electricity market. 7. Availability of system wide data base on web at various voltage levels will help the customer to decide specification of newly procured equipment to overcome incompatibility issues.
Reference [3], has proposed PQ monitoring system with central monitoring. Proposed monitoring system basically consists of one power quality analyzer and multiple power quality meters. Power quality meters only act as raw data acquisition system and power quality analyzer performs all calculations and have analysis algorithm. According to author the proposed system is very economical especially for large
8. Availability of system wide power quality data base on web will be useful for manufacture of sensitive equipment to make required changes in design to make their equipment compatible to existing electrical environment. 2
Development of Web Based Power Quality Monitoring System for Handling User Custom Power Quality Query and Auto Power ...
components of proposed system consist of following hardware components: 1. PQ monitoring instrument. 2. Modems for communications 3. Central server and workstation 4. UPS 5. Back up tape 6. GPS
scale system, because the price of power quality meter can be dramatically lowered in the proposed scheme. One of the draw back of this system is that as the individual PQ meter transfers raw data, the communication burden will be heavy. But according to authors current Ethernet communication technology will help to solve the problem in near future. PQ monitoring algorithm that detects events and captures steady state trends. Result of voltage sag waveform captured and waveform and harmonic components for current harmonics are only presented.
The captured data through power quality monitor is outputted to communication network through a MODEM. The standard outputs of the meter include supply frequencies, RMS voltage, RMS current, voltage harmonic spectrum and current harmonic spectrum up to the 127th harmonic current, crest factor, KW, KVA, KVAR, displacement power factor and total power factor, phase angles at the fundamental component and at each harmonic component would also be displayed. The PQ meter measures and store the data then the data is transmitted to the central system server through leased dial up line, customer intranet, Ethernet network or DSL modem. The network is specially designed to be able to use various communication means, so that different customer needs would be met. For very remote sites where communication network is not available, wireless communication using GMS format or radio would be adopted.
Leandro Fabrico Auler etal [9], presented new protocols for monitoring power quality in an industrial environment by means of Ethernet networks to perform a real time waveform monitoring, allowing an oscilloscope like analysis. In reference [14], a system approach to power quality monitoring for performance assessment is presented. The configuration complexity of a PQ monitoring system depends primarily upon the number of instruments used to acquire the information and number of people who need to utilize it. The simplest monitoring system could be of self contained circuit monitor or device built in sensitive load. The real value of the monitoring system is an automatic data downloading from the measuring instruments. RS 232 port is used to communicate with a number of monitors. Two way communications between work station and monitors is becoming more and more important. A complete monitoring should fully utilize the networking infrastructure. Data can also down loaded from monitoring system by way of broad band modems, as well as through internet or intranet connection. Access to the data base is given through password. Another option for data access is to use the standard world wide browser to query a database server. Customer can be given password to view summaries and reports via the internet. The internet offers an effective vehicle for providing power quality monitoring as an enhanced level of service.
In previously published literature the various facilities such as harmonic compliance, plotting events on ITIC, SEMI F47 or customer specified voltage tolerance curve and selection of various characteristics of specified power quality event are not provided. The work presented in this paper provides all these facilities and is more user friendly.
4 Web Based Power Quality Monitoring System Experimental Set Up The web based system developed is having following facility: 1. The computer server is used to store monitored data and implemented on Tomcat web server. 2. A multi-Giga byte drive is used to store the power quality data. 3. With this Giga byte drive, it is possible to store data for two years in case of on line monitoring. 4. Internet is used to disseminate the power quality data to concerned engineers and users. 5. Using web based system user is allowed to access data from existing data base with user name and password. 6. Facility of custom query related to various power quality parameters is provided.
In reference [12], web based access to the power quality monitoring system is presented. According to author the information from the power quality monitor should be available immediately and conveniently and the best option available is to make the system completely accessible via internet or intranet. Theses systems are connected directly to the network with TCP/IP communications. With such a system any one who needs data related to particular event or summarized performance over a month can get access to the information. Ringo PK Lee etal [13], explained and demonstrated the architecture of designing a web based multi channel power quality monitoring system for a large network. The various
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User can select the query parameters, the algorithm find out the result of the query. 8. In case of on line power quality monitored data, a custom report is generated based on threshold set by user and it is emailed to the specified person after uploading of data into a laptop connected to the power quality monitor via public modem. 9. Facility to provide harmonic compliance as per IEEE 519-1992 is provided. 10. Auto plotting of monitored RMS voltage events such as voltage sag and swell from database on ITIC curve, or user supplied curve. 11. Trending plot of total harmonic voltage and current distortion facility is available. This trend can be selected for the one day, one week, one month, one year or any arbitrary period of time based on the period during which data was monitored. It is a convenient method to summarize the power quality of a site over a given period of time.
Web based power quality monitoring system consists of two sections: 1. 2.
Power quality monitoring system is implemented with: 1. 2. 3.
2. 3.
Monitoring software is software which controls the power quality analyzer through TCP/IP connectivity. This software is written in Java and performs following steps. 1. Start the recording of the monitor as per user selectable date and time setting. 2. Stop the recording after the specific time interval. 3. Transfer the power quality data from power quality monitor (flash card memory) to computer secondary storage device. 4. After transferring the data it converts this unsorted data into MS-ACESS compatible database. 5. Power quality database is further classified into sub categories. 6. This database is used to create user defined power quality report. 7. This report is then sent to concerned person as an email attachment.
A computer with an internet connection, and a Mozilla compatible web server. The address (URL) of the power quality database. Appropriate user ID and password to access database.
No special hardware, software or training is required for user. The users are allowed to provide access, for reading data base only and not allowed to change the existing monitored data base. All of this allows the user to view power quality data without having to install a large amount of software in their computers. 1.
2.
Monitoring software (running on laptop or PC). Power quality analyzer (HIOKI 3196). CDMA phone.
4.1 Monitoring software
For a user to view data, following three things are required: 1.
Monitoring systems. Web based power quality database server.
4.2 Power quality monitor For power quality monitoring, HIOKI 3196 power quality analyzer is used. This device has Ethernet and RS 232 connectivity.
While the data gathering and characterization is conducted at central location, the information is available to user with web browser. Security protocols and passwords were built to keep unauthorized personal from viewing highly confidential and often propriety data.
Figure 1 shows a web based power quality monitoring experimental set up and figure 2 shows the automatic download software window. The user can enter various entries such as day, month, year, hour, minutes, setting and path. The other function provided are directory check, download, start recording, stop recording, reset the data, automation and format card. Figure 3 shows the main page of the power quality monitoring database server. The user is required to enter username and password to login to the system. After successful login it displays the second page of power quality database server on screen. Figure 4 shows second page of power quality data base server. The various selectable facilities provided for user are database available, custom query, THD curve, email notification and compliance
The power quality web based system server makes power quality information and data available to the user. In order to access the data, the user needs to know address of power quality data site, have a web browser such as Netscape navigator or Microsoft internet explorer and required username and password to get access to the web based power quality monitoring system. Both recent and historical data can be viewed at any time from any internet connected PC using web browser. This system is tested on local area network of the institute and implemented on internet.
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Development of Web Based Power Quality Monitoring System for Handling User Custom Power Quality Query and Auto Power ...
curve. The next step is to click on the database available, the next page displayed will show the list of various database available. Figure 5 shows the screen showing available database. The user will have to select the data base from the available database. After selecting the database the next step is to click on custom query as shown in figure 6. The various custom query options and selection details is shown in figure 8. After selecting and setting the parameter related to custom and clicking query button developed software will search the query from existing database and the result generated is shown in figure 7. The facility of IEEE 519-1992 harmonic compatibility is shown in figure 9, ITHD trending facility is shown in figure 10 and ITIC curve compatibility evaluation is shown in figure 11.
Figure 3: Main page of web based power quality monitoring system
Figure 1: Web based power quality monitoring setup
Figure 4: Second page of web based power quality monitoring system
Figure 2: The automatic download software version 3.01 for the HIOKI 3196
Figure 5: Web based power quality monitoring system page showing database available
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Figure 6: Web based power quality monitoring system, query selection page
Figure 9: IEEE 519-1992 harmonic compliance
Figure 7: Power quality query result generated by web based power quality monitoring system
Figure 10: ITHD trend plotting facility
Figure 8: Setting power quality query characteristic page
Figure 11: Auto plotting of event on ITIC curve
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Development of Web Based Power Quality Monitoring System for Handling User Custom Power Quality Query and Auto Power ...
The above proposed implemented system will be useful to industrial customers and utilities.
5 Results and Discussion Web based power quality monitoring system has been presented with results. The entire system has been implemented by using Java based monitoring software developed and running on laptop, power quality analyzer (HIOKI 3196) and CDMA phone. The power quality web based implemented system allows user to access the power quality information. In order to access the data, the user needs to know address of power quality data site, have a web browser such as internet explorer and requires valid username and password to login to the web based system. Both recent and historical data can be viewed at any time from any internet connected PC through web browser. This system is tested on local area network of the institute and can be implemented on internet. In case of online power quality monitored data, based on the user set event threshold, during starting of PQ monitoring provides auto email notification of PQ report automatically to all email ID’s specified by the user, after data is uploaded to a laptop connected to power quality monitor via public modem.
References [1] A. K. Khan, “Monitoring power for the future”, IEE Power Engineering Journal, April 2001. [2] C. J. Melhorn, S. Smith, F. Sinicola, P. Muccio, “Utilization of web based power quality monitoring to assess customer power system performance”. [3] D. J. Won etal, “Development of power quality monitoring system with central processing scheme”, 0-78037519-X, IEEE 2002. [4] IEEE Std. 1159-1995-IEEE “Recommended practice for monitoring electric power quality”. [5] J. Arrilaga etal, “Power system harmonic analysis”, New York; Wiley 1997. [6] J. Arrillaga, S. Chen, N. R. Waston, “Power system quality assessment”, John Wiley and Sons, 2000. [7] L. Brooks, R. C. Dugan etal, “Indices for assessing utility distribution system RMS variation performance”, IEEE transactions on power delivery, Vol. 13, No.1, pp 245-259, January 1998. [8] L. Cristaldi, A. Ferrero Etal, “A distributed system for electric power quality measurement”, IEEE Transactions on Instrumentation and Measurements, Vol. 51, No. 4, August 2002. [9] L. Fabrico, D. Roberto’ Amore, “Power quality monitoring and control using Ethernet Network”, 0-78037671-4, IEEE 2002. [10] M. H. J. Bollen, “Understanding power quality problem; voltage sags and interruptions”, New York: IEEE Press, Series on Power Engineering, 2000. [11] McGranghan Mark, “Trends in power quality monitoring”, IEEE Power Engineering Review, Oct.2001. [12] R. Ignall, M. M. Granaghan, “Power quality monitoring for high reliability system”. [13] Ringo etal, “A web based with multi-channel power quality monitoring system for a large network, power system management and control”, IEE Conference Publication, No. 482, April 2002. [14] S. Dan, M. M. Granaghan, A. Sundaram, “A system Approach to power quality monitoring for performance assessment
6 Conclusion The developed web based online power quality monitored data system, based on the user set event threshold, during starting of PQ monitoring provides auto email notification of PQ report automatically to all email IDs specified by the user, after data is uploaded to a laptop connected to power quality monitor via public modem. The various advantages of proposed scheme are: 1. Ability of the algorithm to automatically detect power quality user requested query related to various power quality abnormalities from the existing database. 2. Ability to automatically detect the abnormal variations from normal variation set by user during start of power quality monitoring from uploaded PQ monitored data on laptop and auto email notification to user. 3. Facility to auto plotting of various rms voltage variation events such as voltage sag and swell on ITIC curve. 4. Facility of trending plot of total harmonic voltage and current. These trends can be selected for one day, one week, one month and one year or any arbitrary period of time based on the period for which data was monitored.
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