Design and Analysis of PowerMount Comm. Structures for T-Mobile of MDL Engg Soln Inc. a client from USA.
Saturday, September 3, 2016
Monday, June 13, 2016
Generator excitation control operation
Increasing the output voltage of a generator is achieved by adjusting the magnitude of the excitation current. This
happens because as DC current is increased, the rotating magnetic field increases thereby increasing the generator voltage induced in the stator conductor. As the voltage is increased, the generator will transfer more MVAR into the power system.
Instead of collector rings, suppose that a brushless generator above is used in our example. The exciter is provided from the DC winding which is wound in the stator. The rotor produces ac current that is feed into the rectifier built in the shaft. The rectifier converts AC to DC and feed the rotor windings.
To control of the rectifier output in the field windings of the excitation generator, voltage regulator receives its command signal from the AC voltage controller which monitors the ac voltage of the monitor.
The limitation of the generator due to current in the stator should follow within the machine capability curve. Increasing the excitation current of the generator to deliver MVAR will produce heating in rotor winding. alternatively, if the excitation is reduced voltage and VARS will fall. then the machine will have weak magnetic field .
In the capability curve, the horizontal axis is the reactive power in per unit quantity, where 1 pu =159 MVAR and the vertical axis is the active power per unit quantity.
Instead of collector rings, suppose that a brushless generator above is used in our example. The exciter is provided from the DC winding which is wound in the stator. The rotor produces ac current that is feed into the rectifier built in the shaft. The rectifier converts AC to DC and feed the rotor windings.
To control of the rectifier output in the field windings of the excitation generator, voltage regulator receives its command signal from the AC voltage controller which monitors the ac voltage of the monitor.
The limitation of the generator due to current in the stator should follow within the machine capability curve. Increasing the excitation current of the generator to deliver MVAR will produce heating in rotor winding. alternatively, if the excitation is reduced voltage and VARS will fall. then the machine will have weak magnetic field .
Technical Data for Generator 60WX18Z-090 with Static Excitation 158,8 MVA 13800 V 60 Hz p.f. = 0,85 Tcg = 33 °C Temp.-Cl. = 130(B |
Monday, April 2, 2012
EEWeb Website of the Day April 2, 2012
This blog is featured in EEWeb - Electrical Engineering Community, as website of the day for April 2, 2012. This is an excellent recognition from a popular electrical engineering community website for hardware engineers. I'm happy and honored that this blog was on the front page of the EEweb and was included in the list of impressive websites that EEweb has recognized in the past.
Thank you EEWeb!
Update: 2013
The old name of this website was "Mathematics and Engineering Topics" and now changed to "EngineerMaths.com". The change was due to transfer of this website from free domain to a premium domain name. Every articles and feeds will be automatically redirected into our new domain. For example, when you visit our old address [Mathematics and Engineering Topics], it will redirect you to our new address.
Thank you EEWeb!
Update: 2013
The old name of this website was "Mathematics and Engineering Topics" and now changed to "EngineerMaths.com". The change was due to transfer of this website from free domain to a premium domain name. Every articles and feeds will be automatically redirected into our new domain. For example, when you visit our old address [Mathematics and Engineering Topics], it will redirect you to our new address.
Screenshot of Enginering and Mathematics Topics in EEweb |
Screenshot of EEweb home page |
Wednesday, March 28, 2012
Electronic Control of automatic Recloser
Electronic Recloser Contol is compromised of a number of programmable, solid solid-state electronic circuits that perform the command fuctions involved in automatic recloser operation. It is used to operate all electronically controlled reclosers.
the control panel of the control unit contains the programming and opening elements of the control.
Parts of the control panel of the electronic recloser:
Minimum trip resistors - Establish the minimum trip current levels for ground and each phase; cartridges are marked in primary amps and clamped in place.
Operation counter - record the cumulative trip operations of the control.
Sequence relay - steps the control through its operating sequence.
Ground- Trip Operation Switch -Blocks all ground in the BLOCK position: prevents unintentional tripping during single -phase switching operations.
Manual Control Switch - In the TRIP position, it locks out the control, advances the sequence relay lockout, and disconnects the battery from the control circuits. In the CLOSE position, it moves the sequence relay to the home position, reconnects the battery and closes recloser. If held in CLOSE position, it will override cold- load inrush ; however, the control will lockout for permanent faults.
Control Fuse- Protects the closing solenoid coil (on reclosers that employ solenoid closing) if closing voltage is too low. connected in series with the closing contactor in the recloser on motor- operated units; connected in series with the contactor rotary solenoid on reclosers that employ solenoid closing
Non- Reclosing Switch - Sets the control for one shot to lockout without disturbing the lockout setting of the operations selector.
Lamp Test Lockout Switch - Enables testing the signal lamp and checking for lockout.
Lockout Indicating Signal lamp - Provides visual indication of control lockout
Battery Test Tetminals - Enable checking battery voltage, charging rate ,and quiescent current drain.
Reset -Delay Plug - Determines the delay interval before the control resets after a successful reclosure during an operation sequence. the delay value is determined by position of the plug in socket adapter.
Phase Trip Timing Plugs - Provide a variety of current integrated timing curves on individual plugs for coordinating the phase trip operation with backup and downline protective devices.
Ground Trip Timing Plugs -Provide a variety of current integrated timing curves on individual plug for coordinating the ground-trip operation with backup and downline protective devices.
Reclosing Interval Plugs - Determines the delay interval for each closing operation. The delay value is determined by the position of the plug in the socket adapter. An instantaneous plug is available for the first reclose interval only.
Phase Trip Selector - Programs the number of fast phase trip operations as defined by the timing pug in Socket 1; the remaining (slower) operations to lockout are defined by the plug in phase trip socket 2
Lockout Selector - Programs the total number of operations to lockout.
Ground Trip Selector- Programs the number of fast ground trip operations as defined by the timing plug in socket 1; the remaining (slower) operations to lockout are defined by the plug in ground trip socket 2
the control panel of the control unit contains the programming and opening elements of the control.
Parts of the control panel of the electronic recloser:
Minimum trip resistors - Establish the minimum trip current levels for ground and each phase; cartridges are marked in primary amps and clamped in place.
Operation counter - record the cumulative trip operations of the control.
Sequence relay - steps the control through its operating sequence.
Ground- Trip Operation Switch -Blocks all ground in the BLOCK position: prevents unintentional tripping during single -phase switching operations.
Recloser Control panel |
Manual Control Switch - In the TRIP position, it locks out the control, advances the sequence relay lockout, and disconnects the battery from the control circuits. In the CLOSE position, it moves the sequence relay to the home position, reconnects the battery and closes recloser. If held in CLOSE position, it will override cold- load inrush ; however, the control will lockout for permanent faults.
Control Fuse- Protects the closing solenoid coil (on reclosers that employ solenoid closing) if closing voltage is too low. connected in series with the closing contactor in the recloser on motor- operated units; connected in series with the contactor rotary solenoid on reclosers that employ solenoid closing
Non- Reclosing Switch - Sets the control for one shot to lockout without disturbing the lockout setting of the operations selector.
Lamp Test Lockout Switch - Enables testing the signal lamp and checking for lockout.
Lockout Indicating Signal lamp - Provides visual indication of control lockout
Battery Test Tetminals - Enable checking battery voltage, charging rate ,and quiescent current drain.
Reset -Delay Plug - Determines the delay interval before the control resets after a successful reclosure during an operation sequence. the delay value is determined by position of the plug in socket adapter.
Phase Trip Timing Plugs - Provide a variety of current integrated timing curves on individual plugs for coordinating the phase trip operation with backup and downline protective devices.
Ground Trip Timing Plugs -Provide a variety of current integrated timing curves on individual plug for coordinating the ground-trip operation with backup and downline protective devices.
Reclosing Interval Plugs - Determines the delay interval for each closing operation. The delay value is determined by the position of the plug in the socket adapter. An instantaneous plug is available for the first reclose interval only.
Phase Trip Selector - Programs the number of fast phase trip operations as defined by the timing pug in Socket 1; the remaining (slower) operations to lockout are defined by the plug in phase trip socket 2
Lockout Selector - Programs the total number of operations to lockout.
Ground Trip Selector- Programs the number of fast ground trip operations as defined by the timing plug in socket 1; the remaining (slower) operations to lockout are defined by the plug in ground trip socket 2
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