Saturday, September 3, 2016

Power System Study of 3x135 MW CFB Thermal Power Plant FDCMPC

Our freelancer has undertaken Power System Study for 3x135 MW CFB Thermal Power Plant of FDCMPC in Cagayan De Oro, Misamis Oriental in the Philippines. The scope of the project are Load Flow, Short Circuit Analysis and Motor Starting Analysis.



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 .

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
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.

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.

Screenshot of Enginering and Mathematics Topics in EEweb
Screenshot of Enginering and Mathematics Topics in EEweb


Screenshot of EEweb home page
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.

control panel of electronic recloser
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