Explain the process of conducting a power quality audit, including selecting measurement points and analyzing collected data.

A power quality audit is a systematic assessment of the electrical system to identify, analyze, and resolve power quality problems. The process begins with a preliminary site survey to understand the system's configuration, load characteristics, and any known power quality issues. Selecting appropriate measurement points is crucial. Key locations include the service entrance, points of common coupling (PCC) with other loads, locations with sensitive equipment, and areas where power quality problems are suspected. Measurements should be taken at different times of day and under various operating conditions to capture a representative picture of the system's performance. Typical parameters measured include voltage variations (sags, swells, interruptions), harmonic distortion (voltage and current), transient voltages, and power factor. Data is collected using power quality analyzers, which record voltage, current, and other parameters over a specified period. After data collection, analysis involves examining the recorded waveforms, trends, and statistical summaries. Harmonic analysis identifies the presence and magnitude of different harmonic frequencies. Voltage sag and swell analysis reveals the frequency and severity of voltage disturbances. Transient analysis identifies the source and characteristics of transient voltages. Power factor analysis assesses the efficiency of power utilization. The audit concludes with a report that summarizes the findings, identifies the root causes of any power quality problems, and recommends solutions. These solutions may include installing harmonic filters, improving grounding systems, using surge protection devices, or implementing voltage regulation measures.