Title of Invention

A TIME SYNCHRONIZING UNIT FOR CONTINUOuSLY MONITORING ELCTRICAL SUBSTATIONS

Abstract

1. A time synchronizing unit for continuously monitoring electrical substations, comprising: -a global positioning system receiver CGPS-Rx) for receiving and outputting a pulse in NMEA formatted real time data packets; -a translation unit CTSU) for reading the data packets received from said receiver CGPS-Rx) and for generating and outputting SYNCH signals; and ~ a master display unit CMDU) for receiving and displaying said SYNCH signals for monitoring operations of the electrical substations.

Full Text

The present invention relates to a tine synchronizing unit for continuously monitoring electrical substations. The electrical substations are equipped with monitoring instruments like SETt (sequential event recorder), DR (disturbance recorder), DAS (data acquisiticxi system) and the like. These instruments continuously monitor the operation of the substation and report the abnormal events in real time which enable resolving of power system faults, especially under contigent system conditions. The resolving and correlation of events would require that time base of all such equipment be synchronized to common time base. Most of the equipment in substations is not synchronized to common time or a few of equipment synchronized using radio based broadcast time signals. The accuracy obtained is very low because of degradation of signals in long wave range. The short—wave radio time signals are limited to smaller area with slightly i flip roved accuracy . The main csbject of the present invention is to provide low cost, reliable and accurate synch pulses for synchronizing substation equipment to a common time tag over entire grid, that obviates the drawbacks of the known time synchronizing units. Another object of the invention is to provide a simple, cost effective way of correlating events in time domain. Yet another C3bject of the invention is to cover wide range of equipment with different requirement of synch pulses. The time synchronizinQ unit of the present invention uses the receiver of a glcrtial positioning system C6PS) to enable synchT^onization of time base of all the equipment at extra high voltage (EHV) substations. The time synchronizing unit of the present invention consists of a global positioning system CGPS) receiver and an electronic translator unit. Tbe GPS receiver locks on to the group of satellites and outputs a pulse every one seccMid. This one—second pulse is applied to the electronic translator unit wtiich in—turn outputs four types of synchronization signal to cater to the variety of instruments used in the EHV substations. The time synchronizing unit is programmed to generate appropriate signal. Once programmed it receives the 1/PPS pulse from the GPS receiver and outputs the waveforms for synchronization of other equipment. It also resloves the 1/PPS to microseconds and outputs to large size master display unit fMCHJ). The module also has provision to time stamp one event with microsecond resolution. The various synchronization pulses available are listed below. 1. Serial output - One every second 2. AC voltage - Required voltage can be selected 3. DC Voltage — Required volgage can be set through switch 4. PFC (potential free ccHitacts) AC/DC/PFC repetition rate can be set independently for one PPS (one pulse per second)/one PPM/one PPH using switch. All four signals are available simultaneously (Serial output is used for master display unit). The tine synchronizing unit of the present invention uses a single chip microcontroller for generating finer resulution of real time. This is achieved by making use of the in—built hardware feature of microcontroller along with a dedicated embedded firmware. This finer real time is synchronized to the universal time, which is treated as reference, obtained through global positioning receiver.The resolution of reference time is 1/sec, tirtiich is resolved through above technique to 1/usec. This transformation would enable synchronizing and correcting the time base of the equipment to higher resolutions. The time synchronizing unit includes a global petitioning system (GPS) receiver which locks on to the group of satellites and outputs a pulse every one second. This one second pulse is applied to an electronic translator unit which in turn outputs four types of synchronization signals to cater to the variety of instruments used in the extra high voltage substations. The time synchronizing unit also includes a microcontroller unit with firmware, a synch pulse generating circuit a master display unit liDU and a printer^ The various synch pulse repetition rate and DC synch pulse amplitude can be selected through DIP switch. Thus the present invention provides a time synchronizing unit for continuously monitoring electrical substations, con^rising a global positioning system receiver for receiving and outputting a pulse with NMEA formatted real time data packets,a translation unit for reading the data packets received frcMi said receiver and for generating and cmtputting SYNCH signals and a master display unit for monitoring operations of the electrical substations. BRIEF DESCRIPTION OF THE ACCOMPANYIls« I»=tAWIN6S In the accompanying drawings : Figure 1 shows in block diagram form the arrangement of the time synchronizing unit of the present invention, and Figure 2 shows the detailed inter—ccNnnections of the three sections of the time synchronizing unit. The present invention will now be described in details with reference to the Figures of the drawing. The three sections, global positioning system receiver (GPS-RX),an electronic translation unit CTU) and a master display unit The global positioning system receiver (BPS-RX) consists of three parts : the antenna If a radio frequency front end 2 and a processor 3. This part of the hardware is in the form of modules. The receiver is a 12--channel LI C/A code SPS receiver with radio frequency front end, correlator, navigator and user interface with the processor unit 3. The receiver locks on to a group of satellites and outputs a pulse every second (IH'PS) along with NMEA formatted real time data packets* The real time corresponds to coordinated universal time UTC. The translation unit TU is an embedded unit consisting of an intelligent module 4 and an output module S. The microcontroller /ice of Fig. 1 is the hardware portion of the intelligent module 4 which also contains the embedded firmware. This intelligent module is based on industry standard 8051 families of micro controllers. The intelligent module has a battery backed real time clock Serial output — Real Time data in HH:msSSsmmm:|iiyp AC Voltage - Progranmable Amplitude (0-240V, SfiNz) DC Voltage ~ Programmable Amplitude C0--+ 110V) PFC — Potential Free contact The repetition rate of AC/MI/PFC can be set independently. All signals are available simultaneously. The firmware in the translation unit TU reads the l-PPS and real time data packet data from the global positioning system receiver and generates four types of SYNCH signals as listed above. This real time universal time ccxirdinates CUTCI is compensated for variable offset and converted to 1ST. The time between two successive IPPS is also measured by the firmware. This is suitably appended to 1ST to obtain finer resolutions. The firmware also traps events and stamps the time of occurence with microsecond detail, »^ich was used to validate performance of two time synchronizing units. The master display unit HDU is a large size 12 digit dot matrix display unit on which HHsMH.SSsmmms|i|ip^ is refreshed every second by the translation unit. The universal time coordinates UTC is very high precision reference clcxrk maintained by atomic standards. Time zone offset is algebraically added to the universal time coordinates to get local time. Global positioning, receiver outputs universal coordinated time on its serial port. The potential free contact PFC is the one of the synch signal output available for synchronizing downstream substations equipment. The potential free contact is actually a relay contact free from potential (voltage) and can be configured by user to suit his synchronizing requirements. The specifications of a preferred embodiment of the time synchronizing unit of the present invention is shown below. Spec i f ic at ions GPS Subsystem Receiver — 12 Channels LI-C/A code SPS Time to first fix ¥tot Start - 20 Seccxids (Typical) Warm Start - 45 Seconds (Typical) Cold Start - 65 Seccinds (Typical) Reacquisition -^ Less than one second Communication -* RS 232 Compatible 4800/9600 band NMEA formats Pulse — One pulse per second (IPPS) Timing Subsystem Pulse ^ One pulse per second — IPPS - One pulse per minute — IPPM - One pulse per hour — IPPH WE CLAIM : 1. A time synchronizing unit for continucxisly monitoring electrical substations, comprising s a global positioning system receiver C6PS-Rx) for receiving and outputting a pulse with NMEA formatted real time data packets; - a translaticxi unit (TSU) for reading the data packets received from said receiver CBPS-Rx) and for generating and outputting SYNCH signalsf and - a master display unit CMDU) for receiving and displaying said SYNCH signals for monitoring operations of the electrical substations. 2. The time synchronizing unit as claimed in claim 1, wherein said global positioning system receiver fePSHRx)is a 12—channel LI C/A code SPS receiver. 3. The time synchronizing unit as claimed in claims 1 or 2, wherein said GPS receiver comprises an antenna CI), a radio frequency front end (2) and a processor (3). 4. The time synchronizing unit as claimed in the preceding claims, wherein said translation unit CTU) comprises an intelligent module C4) and an output module (5). 5. The time synchronizing unit as claimed in claim 4, wherein said intelligent module C4) comprises a microcontroller 6. The tine synchronizing unit as claimed in claim 5, wherein said micracontroller (pC) is based on industry standard 8051 family of micrcxiontrollers. 7. The time synchronizing unit as claimed in the preceding claims, ft^erein the SYNCH signals outputted by said translation unit (TU) comprises serial output AC and DC voltages and potential free contact. 8. The time synchronizing unit as claimed in the preceding claims, wherein said master display unit CMDU) is a 12 digit dot matrix display unit. 9. Hie time synchronizing unit as claimed in claim 8, wherein said display unit (MDUI is capable of displaying every second real time data in WsHHsSSsmmmsfnnj 10. A time synchronizing unit for continuously monitoring electrical substations, substantially as herein described and illustrated.

Documents:

484-CHE-2003 AMENDED PAGES OF SPECIFICATION 10-02-2012.pdf

484-CHE-2003 AMENDED CLAIMS 10-02-2012.pdf

484-CHE-2003 AMENDED. CLAIMS 23-02-2012.pdf

484-CHE-2003 CORRESPONDENCE OTHERS 10-02-2012.pdf

484-CHE-2003 CORRESPONDENCE OTHERS 23-02-2012.pdf

484-CHE-2003 CORRESPONDENCE PO.pdf

484-CHE-2003 DRAWINGS.pdf

484-CHE-2003 FORM-18.pdf

484-CHE-2003 POWER OF ATTORNEY 23-02-2012.pdf

484-che-2003-claims.pdf

484-che-2003-correspondnece-others.pdf

484-che-2003-description(complete).pdf

484-che-2003-description(provisional).pdf

484-che-2003-form 1.pdf

484-che-2003-form 3.pdf

484-che-2003-form 4.pdf

484-che-2003-form 5.pdf