EXECUTIVE SUMMARY
Increasingly, within restructured power systems, voltage stability issues are becoming
significant in the way we plan, operate and maintain the system. The involvement of new
players in the electricity power business has led to the proliferation of intra-area and
inter-area transactions of electricity in the transmission network. Typically, these
transactions are of considerably shorter duration and larger variety than that in a
vertically-integrated utility (VIU) structure where a single utility controls power
generation, transmission and distribution within a given area. Not only does this new
operating environment lead to frequent and significant changes in system operating
points and load flow patterns, but it also results in increasing volatility in system
conditions. This leads to potential security and reliability degradation in system
operations, such as in voltage stability.
There is a need to evolve procedures that insure voltage stability in the operation of more
open and diverse power systems. To achieve this aim, power system operators need to be
able to quickly assess from measurable quantities, the operational state of the system
from the voltage stability perspective. At the same time, in case of stability problems, the
responsibility evaluation procedures need to be distinctly identified within the new
operating environment.
The objective of this project was to evolve a framework, within the context of the
restructured power market operations, to incorporate voltage stability assessment into the
power system security, accountability and utilization factors for control devices. In the
course of completing the objective of this project, we have come up with new and
practical algorithms and procedures that can effectively address the incorporation of
voltage stability into market-oriented power system operations. We summarize the
significant outcomes of our work as given below.
􀂃 Dynamic modeling of generators, governors, ULTC, switched capacitor and loads
using EUROSTAG has been carried to study dynamic voltage stability and the
importance of dynamic reserves to maintain stability [8]. Detecting dynamic voltage
collapse using state information has been investigated for a variety of dynamic
disturbances [4]. Static modeling of FACTS devices in investigating voltage stability
studies also has been carried out. It is observed that usage of devices such as TCSC
and SVC could improve stability margin significantly [3].
􀂃 A new way of using bifurcation analysis, using the unreduced Jacobian matrix [7] that
avoids singularity induced infinity problem and is computationally attractive, has
been formulated.
􀂃 Within the context of an open power market, the responsibility evaluation of a
potential voltage collapse assumes significance. Using bifurcation analysis, a
procedure to allocate contribution of generators, transmission and control elements in
voltage stability has been evolved [6]. This could be used as the basis for evaluating
the utilization factors and the pricing of control elements in a power system.
iii
􀂃 An algorithm to compute Optimal Power Flow incorporating voltage stability has
been proposed [1]. The voltage stability constraint is computed from the power flow
state variables and the network topology. This algorithm has been applied further to
evaluate reliability indices in planning stages [2]. The incorporation of voltage
stability enhancement devices (such as FACTS devices) into the algorithm has also
been formulated [3].
􀂃 The framework for transaction-based power flow analysis for transmission utilization
allocation has been proposed [10]. The methods to model transactions for both pool
type and point-to-point long-term bilateral type transaction have been designed. This
analysis has been used to address the approach to equitable loss allocation in a
competitive market [11]. The approach has been applied to congestion management
and responsibility evaluation in such a market [9].
􀂃 A new way to evaluate voltage stability responsibility in a composite market model
framework, having both the pool type spot market and the bilateral long-term
transactions, has been devised [5]. This decomposition approach has the potential to
address voltage stability usage, voltage security pricing and responsibility settlement
in a transaction-based power market.
赣公网安备36040302000210号 )|网站地图
狗仔卡
发表于 2008-5-9 04:32:32
提升卡
置顶卡
沉默卡
喧嚣卡
变色卡
显身卡
发表于 2008-5-9 18:55:56
