Overlaying control mechanism for solar PV inverters in the LV distribution network

Demonstration of communication‐basedthree‐layer‐controlarchitecture for providing network services to distribution system operators

“…Each device will determine for itself how it will operate how it will handle control signals coming from the middleware layer. In order to be able to exercise control, this layer may include control solutions such as decentralised control, for example, embedded droop control 1,17 . These decentralised control options do not require information from agents or other devices to operate or handle control signals from the middleware layer.…”

“…The overvoltage problem is addressed by limiting the output power of the inverter. As the voltage at the PoC of an inverter crosses the threshold value ( U c ), the generated power will be limited 17 . The power limiting function is expressed using (3).…”

“…The policymakers and regulators are addressing the challenges in distribution networks by enacting new grid codes, such as the German Erneuerbare Energien Gesetz (EEG), IEEE 929 and IEEE 1547 1,13‐16 . These grid codes support the proliferation of a new generation of solar PV inverters, which are designed with monitoring and control capabilities 17,18 . Furthermore, new developments in power systems (advanced metering infrastructure [AMI]), sensors (intelligent electronic devices) and information and communication technology (ICT) are paving a way for real‐time control of distribution networks 8,19,20 .…”

Coordinated active and reactive power control for overvoltage mitigation in physical LV microgrids

“…Therefore, an effective control methodology is essential to mitigate overvoltage issues and maximise the power outputs. There are various solutions that can deal with overvoltage problems, such as cable reinforcement, transformer tap changer adjustment [6], active power curtailment (APC), and reactive power absorption (RPA) [7]. Cable reinforcement requires huge investment cost and takes a long time to implement, especially for countries like the Netherlands where underground cables constitute the majority of the LV distribution feeders [3].…”

“…APC emerges as an appropriate solution to overvoltage problems because the active power change has a strong impact on the voltage variations [9]. P–V droop control is known as a commonly used among various methods for the APC [6]. Nevertheless, the curtailment is unprofitable for the PV owners, since it leads to the loss of revenue from selling their surplus power.…”