Medium-voltage distribution feeders in open-loop and closed-loop arrangement

Abstract

Abstract. This paper deals with a medium-voltage distribution network. The feeders in the open-loop arrangement are changed to the closed-loop arrangement with the aim to improve reliability of the power supply. The paper focuses on the analysis of transient and steady-state operation in the closed-loop that is established by connecting feeders supplied from two different transformers located in the same transformer substation. The transformers are equipped with the tap changers that can change the amplitude of the 20 kV voltages in steps whilst the phase cannot be changed. The possibilities to control the active and reactive power at both ends of the medium-voltage loop are discussed for the case when only the voltage amplitude can be changed and for the case when the voltage amplitude and phase angle can be changed. A simple algorithm for closed-loop active and reactive control is applied. The results of simulations and field testing performed in a 20 kV network are presented.

Comparison between the particle swarm optimisation and differential evolution approaches for the optimal proportional–integral controllers design during photovoltaic power plants modelling

“…Using our approach the problems related to steady‐state oscillations, as well as optimal MPPT controlling through partial shading, could be avoided. The aforementioned is confirmed by the PVPP integration within a model of the medium‐voltage distribution network [40, 41], as a part of the distribution network in loop operation [40]. In that manner, the PVPP integration into the distribution network and its impact on power distribution are compared for the parameters obtained by both optimisation methods.…”

“…The described PVPP was first included within the medium‐voltage distribution network, as part of the distribution network in loop operation [40, 41]. The discussed medium‐voltage network is shown in Fig.…”

The impact of feeders in closed-loop arrangement on harmonic distortion and power losses

“…In the medium-voltage networks, the feeder in closed-loop arrangements are often used to improve voltage profiles in the feeders with distributed generation, to reduce the power losses caused by electric power transmission or to improve reliability and power quality of the power supply [1] - [5]. According to [2], the closed-loop arrangements of the feeders can be classified as the loops of the type I, type II and type III.…”

“…This work focuses on the loops of type II in mediumvoltage distribution networks [1] and [2]. A special attention is dedicated to the power quality and power losses evaluation in distribution network with the feeders in the open-and closed-loop arrangement.…”

Medium-voltage distribution feeders in closed-loop arrangement – neutral point grounding

“…Control of the loop distribution systems with distributed generation is discussed in [3]. The voltage angles and amplitudes at both end of the loop are used to control the active and reactive power in [4]. This paper focuses on the medium-voltage distribution networks where the loops of the types II and III are established primarily to improve the power supply reliability of extremely sensitive loads.…”