Power System Analysis

Root Cause Analysis

When referring to component failures we are referring to fuses blowing, surge protectors failing, automatic transfer switch failures, switch gear failure, CT's and PT's etc. The failure of these components can be due to power quality problems. High magnitude and fast rise time contribute to insulation breakdown in electrical equipment like rotating machinery, transformers, capacitors, cables, CT's, PT's and switchgear.

Computer problems are most associated with sags and swells. In many cases, even instantaneous short duration phenomena can cause computer power off or data corruption. Lightning or switching operations can also result in computer power off, data corruption or even damaged equipment. High harmonic levels can be another culprit that can cause computer problems.

Digital clocks can be found to run fast or slow when a frequency variation occurs. Frequency variations can affect the operation of rotating machinery or process, which derive their timing from the power frequency such as clocks. The power system frequency is directly related to the rotational speed of generators on the system.

Problems with transformers can be due to transient voltage caused by lightning or switching operations, which can result in degradation or immediate dielectric failure. High magnitude and fast rise time contribute to insulation or transient can cause slow degradation and eventually insulation failure, decreasing equipment mean time between failures. Voltage swells can also reduce the equipment life of transformers over time.

Tripping breakers can be a nuisance problem that can cause sags, power interruptions and industries to go off line. Current swells, overloads, harmonics, voltage swells or transients are the most common cause of tripping breakers.

Backup UPS systems can turn on and off excessively due to voltage sags and transient events. This can generally reduce the life span of a UPS system. Many UPS systems have sensitivity settings. If these are too low then transient events caused by capacitor switch can cause UPS systems to kick on and off many times a day. This can reduce the lifespan of UPS systems.

Root Cause Analysis When referring to component failures we are referring to fuses blowing, surge protectors failing, automatic transfer switch failures, switch gear failure, CT's and PT's etc. The failure of these components can be due to power quality problems. High magnitude and fast rise time contribute to insulation breakdown in electrical equipment like rotating machinery, transformers, capacitors, cables, CT's, PT's and switchgear.

Computer problems are most associated with sags and swells. In many cases, even instantaneous short duration phenomena can cause computer power off or data corruption. Lightning or switching operations can also result in computer power off, data corruption or even damaged equipment. High harmonic levels can be another culprit that can cause computer problems.

Digital clocks can be found to run fast or slow when a frequency variation occurs. Frequency variations can affect the operation of rotating machinery or process, which derive their timing from the power frequency such as clocks. The power system frequency is directly related to the rotational speed of generators on the system.

Problems with transformers can be due to transient voltage caused by lightning or switching operations, which can result in degradation or immediate dielectric failure. High magnitude and fast rise time contribute to insulation or transient can cause slow degradation and eventually insulation failure, decreasing equipment mean time between failures. Voltage swells can also reduce the equipment life of transformers over time.

Tripping breakers can be a nuisance problem that can cause sags, power interruptions and industries to go off line. Current swells, overloads, harmonics, voltage swells or transients are the most common cause of tripping breakers.

Backup UPS systems can turn on and off excessively due to voltage sags and transient events. This can generally reduce the life span of a UPS system. Many UPS systems have sensitivity settings. If these are too low then transient events caused by capacitor switch can cause UPS systems to kick on and off many times a day. This can reduce the lifespan of UPS systems.

Battery Health Monitoring

With increasing emphasize on total reliability and continuity of power - to computers and servers i.e. the UPS Power, performance of the batteries have assumed great significance.

It is startling to learn that the monitoring performed by UPS systems cannot provide adequate protection. Because UPS systems only monitor conditions on the battery bus, no UPS monitors tracks and trends individual battery health. In short, such monitoring systems do not provide adequate protection, as they cannot detect individual battery failures- they only look at the overall string voltage and possibly the discharge cycle.

The UPS system cannot pick out the failed battery and enable you to replace it before your system is at risk, which is the only way to be sure your system will perform when it needs to.

Before we say what solution we offer, let us see what the experts have to opine:

BTECH Inc a U.S. company who specialize in providing Advanced Battery Monitoring Systems have shared their experience on their web site -

HOW DOES BATTERY MONITORING HELP ?
Answer: For the first time, trended battery management data can detect impending battery failures before your back up system is affected. You will know in advance which batteries should be replaced and have the time to act. We will document in this guide- from data at actual customer sites - as how accurate the predictive nature of our data is and show you how to analyze the data for yourself. You will be amazed how fast failures can occur in the sealed VRLA batteries that are now so popular - in some cases, within two weeks. In addition, the failure of these of these VRLAs is catastrophic - meaning your UPS with one bad battery can drop the load. The data shows you how serious this problem really is. Now you can do something about it.

Operational life of a battery varies greatly, depending on the pattern of use i.e. the frequency of power failures, continuous operating time, environment conditions and so on. It is therefore necessary to measure internal resistance and the voltage of the battery with temperature measurement in order to assess the state of the battery. In case unused, over a long period of time, it is necessary to know if there is a particular or a few batteries in a given bank which need to be replaced.

Companies like BTECH Inc have system to be installed in your premises to give continuous monitoring. We do monitoring with the help of HIOKI 3551. HIOKI 3551 is portable set up and can be taken to site.

The PASS/WARNIG/FAIL assessment of a battery state is based on six-way combination of comparisons against upper and lower resistance limits and voltage threshold. The instrument LEDs shows the results visually. The measurement is carried out without shutting down or isolating the batteries. Memory function and printed output options help in trending performance scaling of batteries.