Certified Data Centre Professional (CDCP) Practice Exam 2025 - Free CDCP Practice Questions and Study Guide.

Total Harmonic Current Distortion (THDi) specifically refers to the amount of distortion present in the total current waveform compared to the ideal waveform. This concept is crucial in analyzing power quality in electrical systems, as it quantifies the degree to which the current deviates from being purely sinusoidal due to the presence of harmonics. Harmonics are typically generated by non-linear loads, such as computers and variable speed drives, and they create additional frequencies in the current waveform aside from the fundamental frequency.

THDi is expressed as a percentage and is calculated by comparing the root mean square (RMS) of the harmonic currents to the RMS of the fundamental current. The higher the THDi value, the greater the distortion and potential negative impacts on the electrical system, including overheating and reduced efficiency.

In this context, the correct answer emphasizes Total Distorted Current because it encapsulates the overall effect of distortion that harmonics contribute to the total current. This understanding is essential for data centre professionals tasked with ensuring optimal performance and stability of electrical systems.