Integration Of Distributed Generation Sources Research Articles

Reconfiguration of Active Distribution Networks Equipped with Soft Open Points Considering Protection Constraints

The purpose of active distribution networks (ADNs) is to provide effective control approaches for enhancing the operation of distribution networks (DNs) and greater accommodation of distributed generation (DG) sources. With the integration of DG sources into DNs, several operational problems have drawn attention such as overvoltage and power flow alteration issues. These problems can be dealt with by utilizing distribution network reconfiguration (DNR) and soft open points (SOPs). An SOP is a power electronic device capable of accurately controlling active and reactive power flows. Another significant aspect often overlooked is the coordination of protection devices needed to keep the network safe from damage. When implementing DNR and SOPs in real DNs, protection constraints must be considered. This paper presents an ADN reconfiguration approach that includes DG sources, SOPs, and protection devices. This approach selects the ideal configuration, DG output, and SOP placement and control by employing particle swarm optimization (PSO) to minimize power loss while ensuring the correct operation of protection devices under normal and fault conditions. The proposed approach explicitly formulates constraints on network operation, protection coordination, DG size, and SOP size. Finally, the proposed approach is evaluated using the standard IEEE 33-bus and IEEE 69-bus networks to demonstrate the validity.

A Comparative Study of Different Control Algorithm Used in Unified Power Quality Conditioner (UPQC) for Power Quality (PQ) Improvement

Demand for power is on constant increase and it has necessitated the use of alternative energy sources that are discrete in nature and need conversion for utilisation. For this conversion, use of the semiconductor devices is indispensable, which has its own technical challenges and one among them is power quality (PQ). PQ has gained a widespread attention with the increase in penetration level of distributed generation (DG). Integration of DG sources in the grid introduces PQ issues like harmonics, flickers, voltage swells and sags in the system. Unified power quality conditioner (UPQC) is identified to be a reliable and efficient flexible AC transmission systems (FACTS) controller to mitigate the power quality problems. UPQC is based on a hybrid technology that consists of series and shunt inverters connected via a DC link that provide voltage compensation and current compensation. Characteristics of the UPQC are dependent on embedded control algorithm, which ensures proper voltage regulation at DC link and capacitor-voltage equalisation. This paper compares the control algorithms utilised in UPQC for generating reference signals for providing voltage and current compensation, with a special emphasis to total harmonic distortion (THD).