Adjusting the Requirements to the Allowable Current and Voltage Error in Active Power Systems

An active customer-side (electric) power system is one that features integrated distributed generation (DG) facilities and energy storage systems (ESS). This improves customers' energy security as they can reduce the intake of electricity from the power system within certain timeframes. Besides, this approach enables more efficient use of primary and secondary energy resources for better energy efficiency and conservation. An active power system (APS) may have a great variety of diverse operating conditions that effectively prevent any visual recognition and manual control of its operating modes; besides, they require automatic real-time process control. Such circumstances call for adjustments in the requirements to the structure of communication networks, metering and instrumentation systems, power system protections, monitoring and control systems. The algorithms that are used by phasor measurement units (PMU) and PMU-based smart devices (SD) to estimate current and voltage parameters are of fundamental importance. Active power systems are more demanding with respect to electric power quality and measurement accuracy. Calculations herein show the need to lower the allowable margin of voltage and current error in PMUs, as the existing requirements are not consistent with the functioning of active power systems. The paper analyzes how signals are processed digitally when there are short frequency fluctuations in a wide dynamic range, and how distortion factors affect the sine wave of currents and voltages.