Power quality that protects your equipment

Power quality is the set of parameters that describe how clean and stable the electricity reaching your equipment is: voltage, frequency, harmonic content, phase imbalance, flicker, voltage sags and momentary outages, and transient events. When any of them is out of range, equipment suffers: drives reset, transformers overheat, motors last half their expected life, protections trip falsely. Measuring is the only way to find the root cause of intermittent failures that cannot be reproduced on a test bench.

A proper measurement takes 7 to 14 continuous days with a Class A analyzer connected at the critical point (typically the CFE service entrance or the main panel of the process under study). The reason is to capture the plant's different operating regimes: shift start-ups, production changes, demand peaks, scheduled stoppages, weekends. A 24- or 48-hour measurement is not enough: it misses transient events and cyclical patterns that only show up in extended normal operation.

Passive filters (capacitors with a detuned reactor) are the most economical solution when harmonic distortion is dominated by one or two harmonics (typically the 5th and 7th on networks with drives) and the loads are fairly stable. Active filters are needed when several significant harmonics are present at once, when loads vary a lot during the day, or when dynamic reactive compensation is required. An active filter costs 2 to 4 times more, but it corrects at multiple frequencies and adjusts in real time. The diagnosis decides which one applies.

With a signed technical measurement report from the responsible engineer, documenting total harmonic distortion (THD) of current and voltage, and distortion by individual harmonic, at the point of common coupling (PCC), compared against the IEEE-519 limits according to the short-circuit ratio. If an external or internal audit finds a nonconformity, you need a mitigation plan with a deadline and a closing report after the solution is installed. PSE delivers both documents: the initial diagnostic report and the post-installation verification report.

It depends on the design. Modern certified PV inverters (UL 1741, IEEE 1547) operate within harmonic distortion limits and do not degrade grid quality. But an installation that is not coordinated with the existing power quality can cause problems: resonance between the inverter's output filter and existing capacitor banks, power factor over-correction, conflicts with centralized UPS systems. That is why, in industrial solar projects, we measure power quality first and design the interconnection around the plant's full dynamics.

Yes, and it is usually more efficient to do it in one project. A Class A measurement delivers power factor, imbalance, harmonics, transient events and voltage sags at the same time. One diagnosis supports an integrated solution that can combine a capacitor bank with detuned reactors (solves power factor and filters the critical harmonics), an active filter (power quality and dynamic reactive power) and, where it applies, UPS or AVR for specific critical loads. Working on them in parallel avoids reinstallations and conflicts between independent solutions.