Online Coordinated Voltage Control in Distribution Systems Subjected to Structural Changes and DG Availability

Abstract

The responses of multiple DG units and voltage regulating devices such as tap changers and capacitor banks for correcting the voltage may lead to operational conflicts and oscillatory transients, where distribution systems are subjected to network reconfiguration and changes in availability of the DG units. Therefore, coordinated voltage control is required to minimize control interactions while accounting for the impact of structural changes associated with the network. This paper proposes a strategy for coordinating the operation of multiple voltage regulating devices and DG units in medium voltage (MV) distribution systems, under structural changes and DG availability, for effective voltage control. The proposed strategy aids to minimize the operational conflicts by allowing the farthest voltage regulating device to operate first on a priority scheme designed based on the electrical-distance between voltage regulating devices and DG units, while maximizing the voltage support by the DG units. The proposed coordination scheme is designed to enact with an aid of a substation centered distribution management system (DMS) for online voltage control. The control actions of proposed coordination strategy are tested on a MV distribution system, derived from the state of New South Wales, Australia, through simulations, and results are reported. NOMENCLATURE OLTCOn-load tap changer SVRStep

Hierarchical and distributed control concept for distribution network congestion management

“…Methods can operate in real-time based on measurements or state estimation data (e.g. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]) or predetermine a control schedule for the controllable resources based on forecasted load and production (e.g. [18][19][20][21]) or combine the two approaches [22].…”

“…In centralised methods (e.g. [2][3][4][5][6][7][8][9][10][11][12][13]), measurement data is gathered to one point in the network (usually the control centre), control decisions are made based on that data and control commands are then sent to the controllable resources. The advantages of centralised methods are that they can take into account the whole network when determining the control actions and that they can be relatively easily integrated into existing systems of distribution system operators (DSOs).…”

A New Remote Tap Position Estimation Approach for Open-Delta Step-Voltage Regulator in a Photovoltaic Integrated Distribution Network

“…However, due to cloud transients, PV power can fluctuate more quickly and frequently than customer loads [9]. As a result, SVRs may suffer from excessive tap changes.Currently, there are two main categories of research on tap operations in the solar PV integration area: 1) interaction between solar PV systems and tap operations (PV-Tap) [10][11][12]; 2) coordinated voltage control of PV inverters and voltage regulators (e.g., SVR, OLTC) to mitigate excessive tap operations caused by PV power fluctuations [13][14][15]. However, these researches mostly involve theoretical studies based on simulation, and the use of actual tap positions is rare since tap positions are usually not accessible to customers.…”

Voltage control in power distribution grids equipped with large-scale renewable energy sources

“…A common approach to control coordination is based on rule-based algorithms as demonstrated in [35], [36], [37] or [38]. Those algorithms deliberately enforce interaction between voltage regulating devices.…”

“…Interestingly though, study [35] elaborates on using sensitivity matrix not for control calculation purposes but rather to determine how to split a system into smaller areas with limited impact on each other. Nonetheless, it has been found that sensitivity analysis has its limitations, which strongly affect coordination schemes.…”