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Issue 27 - June 1999
The log parameters and sampling period are selected in the Data Logger window of TapTalk. The control will indefinitely and continually log data to onboard memory according to the time indicated under Maximum Available Data. There is expanded onboard memory in the M-2001B control dedicated to Data Logging. Data Logging will continue until new log parameters or a new sampling period is selected and the Log button is clicked. At this point, all previously-logged data will be lost, unless first saved to a data file. The scrollbar in the Data Logger window is used to select the start and end dates and times of the data logged. When the Download button is clicked, all data selected using the scrollbar will be downloaded to the file displayed within the File box. By comparing data files from different dates and times, the user is able to analyze the data history of the M-2001B and the effected overall system parameters. The new version of the M-2029 TapTalk©© Communications Software makes full use of this and other enhanced features of the M-2001B. However, the software still functions in the same manner-providing the user with access to all control features, including monitoring and programming of all functions, via RS-232 (modem or direct connection), RS485, or fiber optic link. Interested? For more information, contact Beckwith Electric at (727) 544-2326 or e-mail at marketing@beckwithelectric.com.
By Frank Lau, Senior Project Engineer for Beckwith Systems Engineering In 1980, under contract to Public Service Company of New Mexico, a new Syncrotran© Motor Bus Transfer System was developed by Beckwith Electric's custom-design team, Beckwith Systems Engineering (BSE). This Syncrotran System effectively performs the fast, in-phase and residual voltage transfer functions required for a complete bus transfer system. Today, this automatic motor bus transfer system solves a problem plaguing the petroleum and chemical industries at their processing plants as well as maintaining an uninterrupted power supply to the motor bus loads at generating plants.
The Syncrotran System is a high-speed motor bus transfer system used to maintain continuous electrical power in the event of a supply disturbance. The system reduces transients, torsional forces, inrush currents and motor stress, all while keeping and maintaining motor operation. Also, it prevents costly repairs or replacements to electrical motors and their related components. Equipment damage and production downtime due to faulty transfers are virtually eliminated. In fact, the economic benefits in using this product have been realized by many customers in countries around the world. General Electric Co. has used the Syncrotran System at twelve bus stations in Indonesia. Energoprojekt Praha has installed four Syncrotran Systems in the Czech Republic for their Temelin Nuclear Power Station Block No. 1 which are ready to be put in service in the year 2000. They have also purchased another four systems for Block No. 2 of the Temelin Nuclear Power Station. Westinghouse Electric Co. has installed and put in service four Syncrotran Systems at their EI-Kureimat Power Station in Egypt. Typically, most power and industrial plants have motors or loads that must remain active in the event of a shutdown. To accommodate this situation, most facilities have a startup source (Station Service Transformer) and a main source (Unit Auxiliary Transformer). See the Typical Power Plant Bus Transfer System figure. Under normal operation, the main source supplies power to the station bus. During this operation, the startup source circuit breaker is open. When a shutdown of the main source is necessary, the motor loads need to receive power from a new source. The new source, the startup source, must be brought on-line and the main source must be taken off-line. This operation is called a bus transfer.
In the event that the main source experiences a power failure and on receiving transfer commands from the protective relay devices, the Syncrotran System automatically selects an appropriate transfer method-fast, in-phase, or residual voltage (whichever method is available first). The Syncrotran System sends a tripping signal to open the main supply breaker and supervises the closing of the startup supply breaker in order to switch the motor bus loads to the standby power source. In addition, the Syncrotran System also provides a selectable switch for simultaneous or sequential fast transfer function. The simultaneous fast transfer method is used for low-inertia motor bus loads. The system has a protection scheme in the event of a mechanical breaker failure of the main supply breaker during the transfer process. For instance, under the main breaker failure condition, after the successful simultaneous fast transfer operation from main to startup source, the startup breaker is tripped back out after its closure. In the event that the fast transfer is unsuccessful or not completed, the startup breaker is blocked from closing through a block delay transfer circuitry. The purpose of this breaker failure protection scheme is to prevent a hot parallel feed situation of both normal and standby sources from occurring. A high-speed check of the phase angle between the motor bus and the standby source determines if a fast transfer should be attempted. If the phase angle is too large, the fast transfer is blocked and an in-phase transfer will be performed at the next zero crossing of the source and the motor bus. If the motor bus voltage decays below the residual voltage setting before the next zero crossing, then a residual transfer occurs. Front-panel indicators show which type of transfer was accomplished. Although the Syncrotran System was originally developed for a two-breaker scheme associated with utility power generation, it was modified and upgraded to a three-breaker scheme to meet the needs of the processing industries. The whole idea is to prevent damage to the motor, and keep the motor running so that plant processing is uninterrupted. A typical petroleum or chemical facility has two available sources of power from the utility system which provides electrical energy to the plant. In a main-tie-main configuration, each utility supply feeder energizes a bus section with the two bus sections interconnected by a normally-open tie breaker as shown in the Typical Industrial Tie Bus Transfer System. To keep constant power supply to critical motors, power is transferred between the two sources of supply by opening the normally-closed source breaker and closing the normally-open bus tie breaker.
Over the past twenty years, more than 100 Beckwith Syncrotran Systems have been used all over the world. The Dow Chemical Company has installed and used the Syncrotran System at several distribution substations in their Texas operation chemical facilities and plans to install a new system in Argentina. FMC Corporation has put five Syncrotran Systems in service in their hydrogen peroxide plants in Thailand and Canada. Sasol Synthetic Fuel Corporation has installed and put in service eleven Syncrotran Systems in their plants in South Africa. This extensive list of customers is a testament to the Syncrotran System's reliability and technological and economic appeal. Interested? For more information, contact Beckwith Electric at (727) 544-2326 or e-mail at marketing@beckwithelectric.com.
Beckwith Electric's digital multifunction relays were recently selected by the Niagara Mohawk Power Corporation for the modernization of their hydroelectric power system. As a full-service energy provider, Niagara Mohawk serves the energy needs of more than 1.5 million customers throughout a 24,000 square-mile area of upstate New York. Niagara Mohawk is almost a century old and some of their hydroelectric plants date as far back as the 1910's and 1920's. The most modern of these date to the late 1950's meaning that some equipment uses outdated, if not obsolete, relay protection. Recently, Niagara Mohawk assessed the condition of their northern hydro facilities in a continuing effort to improve their system reliability and system economics, and initiated a hydroelectric modernization project. This is when they turned to Beckwith for help with relay protection. Eric Becker, protection engineer for Niagara Mohawk, is not only one of the key players in the modernization effort, but he is also the key contact between Beckwith Electric and Niagara Mohawk. Eric is in charge of protection and control engineering for Niagara Mohawk's northern region. He was first introduced to Beckwith's M-3420 Integrated Protection System at a Pennsylvania Electric Association (PEA) conference approximately three years ago. It was then when he became convinced that Niagara Mohawk should invest in Beckwith products. To date, Niagara Mohawk has purchased forty-nine M-3420 Generator Protection Systems and one M-3310 Transformer Protection System from Beckwith. These products were chosen for their protection, control, monitoring and user interface functions. Becker expressed that the decision to purchase Beckwith products was based on several factors. "They are reliable and easy to test," expressed Eric, referring to the relays' capabilities. The relays possess the capability for remote relay interrogation including the metering of data, relay targets, oscillograph recording and self diagnostics. Eric also asserted that Beckwith products "come with great software." The relays are packaged with Beckwith's IPScom© Communications Software for direct or remote communications access, thus allowing smooth setting, configuring and testing of each unit. IPSplot© Oscillograph Analysis Software is also available for plotting and printing of the downloaded oscillographic data. Furthermore, Eric mentioned that the purchased relays are "easy to install"-due in part to the relays' 19" rack mount design which saves space and installation costs. "I have a good relationship with Beckwith," says Becker. "I receive good customer service. When I call with a problem, I get answers." For reasons like these, Niagara Mohawk will continue to work with Beckwith Electric to progress with its modernization effort.
Articles from Issue 27, June 1999 of Beckwith Electric's Powerlines. |
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An
important new feature added to the M-2001B Digital Tapchanger Control
is Data Logging. When using TapTalk© Communications Software, the
Data Logging feature allows the user to select the parameters, such as
source voltage and tap position, for which the control will log data.
This logged data can then be saved to an Excel- or Lotus 123-compatible
spreadsheet file and plotted in graph form. This Data Logging feature
is in addition to the Spreadsheet Logging feature that was included in
the M-2001A.
