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Harmonic Distortion Analysis and Troubleshooting Failure:

Todays Engineers are finding a Power Quality (PQ) problem that is becoming increasingly apparent is

the harmonic distortion of the fundamental sine waveform. The problem has arisen due to extensive use

of Non Linear Loads (NLL) in todays electrical power systems those alter the sinusoidal shape of the sine

wave causing harmonics generation in the electrics power system. The most common harmonic problemthat we routinely observe in conducting harmonic analysis & field Measurement is the Capacitors

drawing higher currents, bulging, flashing and blasting along with detune filter reactor or switchgear.

Capacitors itself does not cause harmonic problems but if significant Non Linear Loads are present in

power system capacitors aggravate the potential harmonic problem. Any combination of capacitance &

inductance forms a resonance frequency circuit at which the capacitive & inductive reactance equals. If

significant harmonic energy is present either inside the plant or outside in the Grid and its frequency

matches with that of the resonance frequency formed by the Power Factor (PF) correcting capacitors or

Detune Filters it will excite current into an oscillation resulting harmonic mangification in the entire

electrical power system. Its effect can damage critical equipment and reflect in an excessively high

harmonics level.

Our harmonics audit across most industrial segments with Electronics loads document Power Quality

failure issues like VFD/VSD drives electronic card failures, DC drive electronics card failures, Power

Electronics, PLC, DCS, SCADA, UPS or Control CKT card failures; Power Thyristors, SCR, IGBT, Diodes,

spike/surge arrestors, Thyristor Fuse failures; Computer/ Lab/ Data Center Server Hard Disk, CPU,

Control, Communication and/or SMPS Card failures. Passive tune Harmonic Filter suppresses both

voltage and current Harmonics from the supply power. It provides clean & quality power and thus solves

all power and control electronic failure issues. Extensive Analysis of Harmonics across all Industries on

Squirrel Cage AC Induction Motors (SQIM) diagnosed a list of motor harmonic problems. These are high

bearing temperature, unbalance 3phase currents, stator winding failure burn, ground, phase short

circuit or melt with winding coil open circuit. Stator windings fail or Rotor Bar damage during motor

start with high inertia loads due to magnetic saturation that lead to excessively high motor starting

current overrun condition. Motor failure happens with high Harmonic Distortion in power systems

because of the use of non linear loads. Passive tune harmonic filter mitigates harmonic distortions from

the Motors power supply system that prevents its failure. Harmonic Audit & Measurements on Slip Ring

AC Motors (SRIM) across most power intensive industries has developed a list of Encon audited

harmonic failure issues. Those are high bearing temperatures, unbalanced 3phase current, stator

winding failures burned, grounded, phase short circuited, melted with coil winding opened up. Rotors

external copper link, ring or air cooled resistance burn from prolonged harmonics overheating and even

the sturdy rotor windings fail. Motors Stator or Rotor winding fails while motor starting with high mass

loads due to magnetic saturations leading to excessively high motor starting current overrun conditions.

Harmonic Survey for HT SRIM specific Power Quality failure issues include insulation failure or terminal

connection melting between rotor coil and its slip ring, rotor shaft and/or its gear box (GB) damage or

break down. Those happen if excessively high harmonic voltage or current is present in factory's

electrical power system or due to series harmonics resonance on interaction between utility/grids

harmonic and plants electrical power systems impedance. Passive Harmonic Filter blocks grid/utility

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related harmonic resonance and blocks any possibility of such extreme Harmonic Distortions entering

into the that prevent Motor failures.

For DC Motors (DCM) list of Encon surveyed harmonic problems include field overcurrent, commutator

overheating, irregular gaps between commutator segments happens when soldering bond between

them gives up, dc motor field winding failure burning, earthing, melting or winding coil opening up, dcmotor armature winding failure burning, earthing, melting or winding coil opening up and occasionally

even the sturdy commutator fails from excessively high harmonics current overheating. Encon

harmonics survey on Switchgear lists down encountered power quality problems like overheating,

blackening, burning or blasting of Fuse/SFU, its Lyra/U type contact that holds both ends of the Fuses I

type contact overheats with harmonics current thereby slowly loosing its spring tension that eventually

results in abrupt Fuse/ SFU flashing or blasting; Air Circuit Breaker (ACB) both Moving Jaw (U type

contact) and Fixed Jaw (I type contact) overheat, slowly burn and eventually blast with minor fault

within its Electric Power Systems, Molded Case Circuit Breaker (MCCB) fixed and moving contacts welds

with prolonged harmonics overheating; Power Contactors fixed & moving contacts chatter & eventually

get welded due to prolonged harmonic overheat. Current Transformer (CT) copper winding fails withburns, grounds, short circuits, melts or open circuit. Potential Transformer (PT) winding

fails/flashes/blasts with burns, grounds, shorts circuit, melts or open circuits. Encon harmonics study on

Bus Bar and Cable delineates power quality issues as like cable lug overheating and terminal insulation

burning, high bus bar noise & vibration problems, 3phase voltage unbalance alone the bus bar running

length, irregular voltage drop between phases at the load ends of the bus bars or cables. Encons Power

Quality Analysis on high voltage (HV/HT) Power Transformer & low tension (LT/LV) Distribution

Transformers diagnoses mostly transformer HV/HT high voltage winding failure issues like burn, ground,

phase short circuit, melt or open circuit. Those happen due to series harmonics resonance on

interactions between utility/grid harmonics and plants electrical power systems. Passive Harmonic Filter

blocks grid/utility related harmonic resonances and thus removes such Power Quality Disturbances fromtransformers power system. Another harmonic problem that affects a power or distribution transformer

is the presence of high current/voltage harmonic within the plant or parallel harmonic resonance on

interactions between Capacitors/ Detune Filters and plant power systems impedance. It could devastate

transformers winding either HV or LV which could fail, burn, ground, short or melt causing an open

circuit. Tune Harmonic Filter solves any resonance problem either grid ignited/initiated series harmonics

resonance or in house plant originated parallel harmonic resonance. It suppresses both voltage and

current harmonics. It thus provides the most comprehensive Power Quality Solutions. Passive Harmonic

Filter reduces transformer winding temperature up to 10deg.Celsius depending upon its power system

Harmonic Distortion levels, increases energy efficiency, strengthens insulation and enhances its life of

operations. Encon Power Quality Survey for industrial Cogeneration Steam Power Plant (coal based or

green fuels like bagasse/ rise husk/ agro waste based) diagnosed mostly high winding temperature

problem for TG Alternator/ Generator. Its either due to high voltage/current Harmonics Distortion

within the plant or Parallel Harmonic Resonance from interaction between capacitor/ Detune Filter and

its electrics power system. Passive tune Harmonic Filters mitigate generator overheating, reduce up to

10deg.Celsius generator winding temperature depending upon Harmonic Distortions level in its electric

power system. Our Harmonic Audits for power plant Turbines diagnose numerous harmonic related

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issues showing up at its mechanical performance. Those are Turbine Bearing overheating, high noise

vibrations or damage; Turbine to Generator gear box (GB) Shaft high vibration noise or damage, gear

box high noise vibration, overheat or damage. Those happen mostly due to series harmonic resonance

on interactions between utility/grids harmonic and plants electrical power systems impedance. Passive

Harmonics Filters block the possibility of harmonic resonances thus eliminating such power quality

disturbances. It saves the turbine and its critical components. Another major turbine related harmonic

problem that Co Gen power plants turbine encounters originate from in house plant harmonics or from

the parallel harmonic resonance through interaction of Capacitor/ detune filter with its electrical power

systems impedance. Turbine fails to deliver its full Power/kW capacity and its Nozzle Chest Pressure

rises close to its tripping limit which is 80% of inlet steam pressure; at much less of its rated Power/kW

delivery point. Passive tune Harmonics Filters effectively suppress voltage/current harmonics at Turbine

Generators power system, slash turbine chest pressure up to 30% depending upon its power systems

Harmonic Distortion level. It thus releases excess turbine capacity for higher productivity, slashes

turbine steam consumption and effects energy conservation for plants higher profitability.

Conventional engineering approach lowers load factor wherein degree of equipment derating scales upwith degree of NLL. It helps in skirting the problem but with a guzzling infrastructure that not only

produces lesser quality product but also requires higher investment cost. Power system though

manages to survive harmonic but the virus remains in dormant stage. And occasionally strikes under

favourable conditions that cause poor voltage and frequency regulation; nuisance trip or even

equipment failure. Electronics are first to fail being most susceptible followed by capacitor, fuse,

switchgear, motorac/dc/servo, ct, pt, transformer, cable and terminations. You may like to visit Our

Credentials that list down variety of problems those we are regularly called upon to trouble-shoot. In-

addition you may like to visit Knowledge Center for ways & means of its eradication.

Encon Smart Solutions reach right at the melting pot wherein the Problems of Power Quality lies and

mitigate it most effectively & very efficiently. This is the domain and usefulness of Passive Tune

Harmonics Filter that reaps rich rewards that you can count on. Encon Harmonic Filter reconstructs

distorted sinusoidal waveform back into sine wave that eliminate bad Power Quality Surges of voltage

dips, current swings & power fluctuations. "Encon Ih Filter" acts as if like injecting ageless potion into

your plants and machineries transforming them instantly into impossible is nothing like performances.

The extent of harmonic distortions in an Electrical Power Systems or for that matter the spread of bad

Power Quality depends upon the immunity of an individual electricals distribution system namely the

short circuit impedance stability of the power system. This simple fact delineates Power Quality &

Harmonics Distortions correction project is not a mass manufacturing process. It also explains why

worldwide many peer solutions particularly with Active Harmonic filters are increasingly translating into

a medicine worst than the disease itself. An on-site power quality audits and harmonics distortion

measurements is a safer approach though not mandatory. It is also possible to design an effective Power

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Quality Harmonics Solution from distance if power systems Single Line Diagram (SLD) and load data

either running or estimated design loads, is furnished.