A robotic welding cell can run perfectly for hours and still expose a serious weakness in the factory power system when several lines start together. The symptom may be a hot neutral conductor, a nuisance trip, a voltage complaint from a servo drive, or a transformer that operates above its expected temperature. In many cases, the root cause is not a single defective machine. It is three-phase loa...
A vehicle body shop can run hundreds of welding points per minute, while robots, presses, conveyors, paint lines and HVAC systems change their electrical demand continuously. The production line may look mechanically stable, but the electrical load seen by the transformer is not. Rapid reactive-power changes, low power factor, voltage fluctuation and harmonic current can appear whenever several we...
Transformer Overheating Explained: Why It Happens Below Rated Load A transformer can run unusually hot even when the connected load appears safely below its nameplate rating. Current may seem acceptable while winding or enclosure temperatures continue rising. This often happens because loading is assessed only in kilowatts or average amperes. Harmonics, imbalance, poor power factor and inad...
A 480 V transformer that runs within nameplate kVA can develop abnormal temperature rise when VFDs, UPS rectifiers, and switched-mode loads inject high harmonic current into its secondary bus. The transformer does not see only useful fundamental current; it carries distorted current through its windings, terminations, and neutral conductor hour after hour. An Active Harmonic Filter measures...
Why a Solar Plant Needs Active Compensation A Static Var Generator (SVG) is an active, IGBT-based power-electronics compensator that stabilises voltage, supplies or absorbs reactive power and filters harmonic current at the point of common coupling (PCC) of a solar plant. It turns unstable PV output into grid-compliant power for EPC contractors, electrical engineers, procurement teams and power-qu...
Even-order harmonics are current and voltage components at even multiples of the fundamental frequency — the 2nd, 4th, 6th and higher orders — that appear as asymmetric distortion in a three-phase power system. They behave differently from the familiar 3rd, 5th and 7th odd harmonics: balanced six-pulse rectifiers do not generate them, but asymmetry does. Half-controlled bridges, DC-off...
High THDi — total harmonic distortion of current — is the ratio of the RMS value of all current harmonics to the fundamental current, expressed as a percentage. It rises when nonlinear loads such as variable frequency drives (VFDs), rectifiers, UPS units and chargers draw current in pulses instead of a clean sine wave. A high reading must be explained, not simply cleared: measure the s...
Harmonics are extra currents and voltages at integer multiples of the supply frequency that non-linear loads draw on top of the fundamental sine wave. Their effect is costly: transformers, motors and neutral conductors overheat, relays mis-trip, and equipment life shortens even below rated load. This guide covers measurement at the point of common coupling (PCC) and how to compare the main mitigat...