Investigation of distributed generation units placement and sizing based on voltage stability condition indicator (VSCI)

Abstract

Voltage instability in power distribution systems can result in voltage collapse throughout the grid. Today, with the advanced of power generation technology from renewable sources, concerns of utility companies are much being focused on the stability of the grid when there is an integration of distributed generation (DG) in the system. This paper presents a study on DG units placement and sizing in a radial distribution network by using a pre-developed index called Voltage Stability Condition Index (VSCI). In this paper, VSCI is used to determine DG placement candidates, while the value of power losses is used to identify the best DG placement. The proposed method is tested on a standard 33-bus radial distribution network and compared with existing Ettehadi and Aman methods. The effectiveness of the method is presented in terms of reduction in power system losses, maximization of system loadability and voltage quality improvement. Results show that VSCI can be utilized as the voltage stability indicator for DG placement in radial distribution power system. The integration of DG is found to improve voltage stability by increasing the system loadability and reducing the power losses of the network.

An efficient MPPT based photovoltaic control model considering environmental parameters

“…Incremental conductance method is used because of its easy and practical simulation and is also more compatible with environmental factors than other existing methods. The main technique of this method is based on the inclination of the array diagram in terms of voltage at the maximum power point [25], [26].…”

Optimal connection of wind turbines to distribution grid to minimize power loss

“…The first group took the economic problem into account [4]- [11]; most research focused on the minimal active power loss [4]- [11] and the maximal electrical energy capture [10]; some of them, authors took the cost and profit maximization into account [10]. The second group concerns technical issues like power quality, stability, and so on [10]- [12]; some research focused on the voltage stability improvement [10]- [12]. The final group considers multi-objective [14]- [20]; at least two objectives from the technique and economic issues is expected to obtain; in this group, the combination of optimal power loss and voltage stability is well-known [15]- [20].…”

“…The final group considers multi-objective [14]- [20]; at least two objectives from the technique and economic issues is expected to obtain; in this group, the combination of optimal power loss and voltage stability is well-known [15]- [20]. Generally, authors mainly focused on algorithms to obtain the cost function and they did not consider the type of DG (WT, diesel or photovoltaic); the DG unit in these studies often operates in either power quality (PQ) mode or photovoltaic (PV) mode, and authors did not consider which the operation mode is the best [5], [12]. Moreover, the DG units' rating is normally an available value, for example 100 kW, 160 kW, 200 kW, and hence, the DGs' size determined by algorithms is often different from available sizes and we must choose an approximate size; this can make the cost function fail.…”

Load flow analysis using newton raphson method in presence of distributed generation

“…Previous literature study shows that voltage value of DN should be preserved in a well-defined interval, this interval is between the nominal voltage of DN minus 5% and the nominal voltage of DN plus 5%. It means that the voltage value at all the busses is in this range [19], [20], power losses in transmission and distribution lines achieve 4% to 5% of total usage [21]. Thus, the minimization of active and reactive power losses in the distribution networks have a great importance for utilities in worldwide [22], [23].…”