Caveat Lector: Although great care has been taken in the compilation of the information contained on this web site, the authors are not liable for the accuracy in terms of error or omission. The information on this web site is subject to change without notice and without obligation on the part of the authors. The authors shall not be liable for technical failures or for failures beyond their control. Some posts may contain authors' personal opinions and views and the authors do not represent any company, corporation or institution.

Sunday, October 17, 2010

Blackout Restoration Procedure (Substation Operation and Maintenance)

Since a super typhoon is expected to make a landfall here in the Philippines tomorrow, utmost preparation is being implemented by the Substation and Transmission Line personnel. Previous typhoons have caused blackouts so a possibility for another blackout is likely to happen.

Typhoon Preparedness Checklist: Preparing for the Coming of Super Typhoon Juan (International Name: Megi)

As we brace ourselves for the incoming Super Typhoon Juan (international name: Megi), here are a few checklist that we have implemented to minimize the damaging effect of the passage of typhoon to our Substation:

Tuesday, October 12, 2010

Root Cause Analysis: Preventing the HV Current Transformer from Exploding

The golden rule of high voltage instrument transformers is that " Never open a Current Transformer, and Never short a Potential/ Voltage Transformer". In this case, a current transformer has been left open because one slide of the terminal block was at open position. Probable cause is that the last maintenance group which conducted testing on the current transformer forgot to slide back the terminal blocks after they have isolated it. Anyways, the report submitted regarding the problem is stated below:

Monday, October 4, 2010

Emergency Shutdown of Power Circuit Breaker (Arcing due to Insulator Cleaner)

I. Background of the Problem:

115kV Power Circuit Breakers were scheduled for maintenance on September 29, 2010. The breakers were maintained one at a time. The testing for Breaker 1 started at 0601H and ended at 1024H. The testing for Breaker 2 started at 1026H and ended at 1152H. Initial results of the tests were satisfactory for both breakers.

Saturday, September 25, 2010

Power Transformer Electrical and Mechanical protection (Part 2)

This will be the second part of the table about Power Transformer Electrical and Mechanical Protection.

Thursday, September 23, 2010

Power Transformer Electrical and Mechanical protection

While cleaning some of my old stuff, I found a table about Power Transformer electrical and mechanical protection. This had been used as reference for basic troubleshooting with regards to Power Transformer Protection. This had been my guide when I was still working at Transco. Nevertheless, some of the entries needs to be updated so that it may be applicable to other substations.

Sunday, August 8, 2010

Power System Analysis: Tripping of Transmission Line after restoration of Power

I am going to share my analysis on the event that happened recently on our substation. For an overview, there are four substations in radial system, first is the Substation A, next are Substations B, C, and D. The source of power is from substation A going to B, going to C and lastly to D. The distance relays of substation A to C are radially connected. It means that no looking back relay is installed on adjacent substation.

Sunday, August 1, 2010

troubleshooting defective jet water pump motor for drainage system

This morning, our jet water pump cannot draw water out in the Cable Trench Drainage at the substation. In just one year of operation, it baffles us that the water pump is already unusable. Anyways, here are the step by step procedures that we did in trying to repair our beloved pump:

Friday, July 30, 2010

preparation of monthly reports (Part 2)

This is the last part of the topic under monthly reports. Another report that is being prepared monthly is the Transformer load profile(TLP). The TLP will provide the peak load of the Transformer/s and its corresponding date and time.

Wednesday, July 28, 2010

Testing for grounded DC supply in an Ungrounded DC System

In an ungrounded DC System, the positive and negative terminals are not directly connected to ground while in the Grounded DC System, one of either terminal is connected directly to ground. Usually, this DC System is created when the configuration of the AC voltage source connected to the rectifier is in delta-connection and the junction between the rectifiers is not connected to ground.

Monday, July 26, 2010

preparation of monthly reports (Part 1)

Every last Monday of the month, monthly reports are required in our substation. There are at least nine reports to be submitted at our main office were trends and different values are tallied. I am going to discuss all of the reports that we are required to submit.

Friday, July 23, 2010

substation control room building leaks

we have been experiencing leaks from the cracks of the concrete gutter of our substation control room building. Since the building is still part of the substation, I will discuss some of our corrective actions which may help others or open to suggestions from the readers.

Setting or resetting of Frequency Relay at Electric Power Substation

Yesterday was the scheduled setting of Frequency Relay on our substation. Frequency Relay is a device that monitors the increase and decrease of frequency which can isolate a certain feeder if the frequency is unstable.

Monday, July 19, 2010

How to prepare a Substation Daily logsheet

This is to differentiate the logbook to a logsheet. Normally, the logbook entries consist of phrases and sentences which describe the activities that happen in a substation.

Sunday, July 18, 2010

substation engineers and operators guide: logbook

A logbook is a listing of all events and activities done in the substation. It serves a reference by the operators and engineers and a record book for easy retrieval of historical activities and data.