Improved Fast Decoupled Power Flow
Improved Fast Decoupled Power Flow
R. Eid, S. W. Georges and R. A. Jabr
Notre-Dame University, sgeorges@ndu.edu.lb
Abstract
This paper presents an Improved Fast Decoupled Power Flow Method (IFDPFM) based on different strategies of updating the voltage angle (δ) and the bus voltage (V) in each iteration. This method was tested on many IEEE bus test systems. When compared with the Newton-Raphson and with the classical Fast
Decoupled methods, the IFDPFM resulted in large computing savings (in flops) in the order of 70 %, thus in faster convergence.
Keywords: Power Flow, Newton Raphson method, Fast Decoupled method.
I. INTRODUCTION
The power flow analysis is a very important and fundamental tool in power system analysis. Its results play the major role during the operational stages of any system for its control and economic schedule, as well as during expansion and design stages. The purpose of any load flow analysis is to compute precise steady-state voltages and voltage angles of all buses in the network, the real and reactive power flows into every line and transformer, under the assumption of known generation and load.
During the second half of the twentieth century, and after the large technological developments in the fields of digital computers and high-level programming languages, many methods for solving the load flow problem have been developed, such as indirect Gauss-Siedel (bus admittance matrix), direct Gauss-Siedel (bus impedance matrix), Newton-Raphson (NR) and its decoupled versions [1]. Nowadays, many improvements have been added to all these methods involving assumptions and approximations of the transmission lines and bus data, based on real systems conditions [2]-[9].
The Fast Decoupled Power Flow Method (FDPFM) is one of these improved methods, which was based on a simplification of the Newton-Raphson method and reported by Stott and Alsac in
1974[4]. This method and due to its calculations simplifications, fast
R. Eid, S. W. Georges and R. A. Jabr
Notre-Dame University, sgeorges@ndu.edu.lb
Abstract
This paper presents an Improved Fast Decoupled Power Flow Method (IFDPFM) based on different strategies of updating the voltage angle (δ) and the bus voltage (V) in each iteration. This method was tested on many IEEE bus test systems. When compared with the Newton-Raphson and with the classical Fast
Decoupled methods, the IFDPFM resulted in large computing savings (in flops) in the order of 70 %, thus in faster convergence.
Keywords: Power Flow, Newton Raphson method, Fast Decoupled method.
I. INTRODUCTION
The power flow analysis is a very important and fundamental tool in power system analysis. Its results play the major role during the operational stages of any system for its control and economic schedule, as well as during expansion and design stages. The purpose of any load flow analysis is to compute precise steady-state voltages and voltage angles of all buses in the network, the real and reactive power flows into every line and transformer, under the assumption of known generation and load.
During the second half of the twentieth century, and after the large technological developments in the fields of digital computers and high-level programming languages, many methods for solving the load flow problem have been developed, such as indirect Gauss-Siedel (bus admittance matrix), direct Gauss-Siedel (bus impedance matrix), Newton-Raphson (NR) and its decoupled versions [1]. Nowadays, many improvements have been added to all these methods involving assumptions and approximations of the transmission lines and bus data, based on real systems conditions [2]-[9].
The Fast Decoupled Power Flow Method (FDPFM) is one of these improved methods, which was based on a simplification of the Newton-Raphson method and reported by Stott and Alsac in
1974[4]. This method and due to its calculations simplifications, fast
References: mismatch approach.” IEEE Transactions on Power Systems, 4, No.4, p. 1345-1354. Transactions on Power Systems, vol. 12, No. 3, p. 1355-1359. [14] L. Wang, 1991, “heuristic analysis and development in decoupled power flow,” in Proc .of International Conference on Power System Technology, Beijing, p [15] A. Monticelli, 1990, “Fast decoupled load flow: Hypothesis, derivations, and testing,” IEEE Transactions on Power Systems, Vol.5, No.4, p