Identifying Power Flow Control Infeasibilities in Large-Scale Power System Models

2023

Preprint

This paper presents a new methodology for static VAr compensator (SVC) modeling in the power flow problem. The proposed formulation applies sigmoid functions to model the control equations that describe SVCs' steady-state behavior, including their limits consideration. In addition, an improvement to the SVC firing angle model is also proposed to include the droop characteristic in the linear region. The main objective is to develop a power flow formulation considering the full Newton approach. One of the main advantages of the proposed method is that no alternating adjustments are required, even in dealing with boundaries and backoffs procedures. The implementation of a power flow program has been tested using both small-scale tutorial systems and the medium-scale IEEE Nordic system. The results presented validate and indicate the effectiveness of the proposed methodology.

Section: Svcs' Thyristor Firing Angle Methodologymentioning

confidence: 99%

“…where Q G k is given in (9). In accordance with (18), it is determined in Table 2 the control equation residue for each operational states of the SVC. It is worth noting that the condition on which switches sw3 and sw4 present high binary value is never achieved.…”

Section: Svcs' Thyristor Firing Angle Methodologymentioning

confidence: 99%

A New Methodology for SVC Modeling in the Power Flow Problem Based on Sigmoid Functions

Barbosa

2023

Preprint

“…These equations have as principal characteristic the fact that they are nonlinear. In this way, practically all the current power flow commercial programs commonly use different variations of Newton‐Raphson's method 29,30 …”

Section: Introductionmentioning

confidence: 99%

A new particle swarm optimization‐based methodology for determining online static security regions

Tinoco

Int Trans Electr Energ Syst

Peres

et al. 2021

Self Cite

Summary A static security region is a tool that provides information on the steady‐state security conditions, for a given operating point, of a power system in an efficient way. Although this tool aims to be used in the online environment, one of its main characteristics is the high computational time required in the construction process. In this context, this article proposes a new methodology to construct these regions based on the particle swarm optimization (PSO) algorithm to improve computational performance. The proposed adjustments for the PSO algorithm parameters are detailed as well as the process to generate the initial population. The proposed methodology is validated through the study of two power systems. The first one is the well‐known New England system, and the second one is an equivalent of the southern Brazilian system. The presented results validate and clearly indicate the effectiveness of the proposed technique.

“…In [11–15], different full Newton approaches for the governor PF problem are described. In [12] the authors use a flexible representation of control devices by augmenting the basic Newton PF formulation, in polar coordinates, with the steady‐state equations describing each control device and the associated controlled variable, generating an expanded system of equations [16, 17]. The authors [11, 13] use a similar load modelling procedure in PF formulation.…”

Section: Introductionmentioning

confidence: 99%

Tools for handling steady‐state under‐frequency regulation in isolated microgrids

Gatta

IET Renewable Power Generation

Pereira

2019

This study presents two approaches to handling under-frequency regulation in isolated microgrids. The first one is a governor power flow (PF) model in which the generators steady-state governor equations are modeled into a full Newton PF formulation resulting in an augmented sparse linearised system of equations to be solved at each iteration. As a result, it is possible to evaluate the under frequency problem in the case of microgrid islanding as well as to set the reference bus angle to evaluate the possibility of reconnection to the main grid. The second approach presents an optimal PF (OPF) formulation in which the generators governor equations are considered as additional equality constraints to determine the minimum amount of load shedding to keep the system frequency between specified limits. In both methods, it is also used an equation that provides voltage regulation in a droop-based control. The reactive power generation limits in the OPF approach are bounded by a proposed complementarity constraint-based method adapted for the generators' droop-controlled terminal voltage. The proposed approaches are evaluated and validated through the study of the EHV1 Network, a 61-bus 33/11-kV radial distribution system, and the New England test system. Ω L set of candidate buses to the load shedding p 1 , p 2 , p 3 active parameters of the ZIP model q 1 , q 2 , q 3 reactive parameters of the ZIP model K p f active load frequency dependency factor K q f reactive load frequency dependency factor V a k /V b k voltage auxiliary variables for complementarity constraints V k min /V k max min./max. voltage at bus k