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Splitting control is the last resort of security control. By splitting the whole system into several isolated islands, splitting control can ensure system stability and power supply under extremely emergency situation. In this paper, a mixed integer linear programming (MILP) based splitting strategy searching model is proposed. Connectivity constraints and voltage stability margin in each island are...
In order to achieve carbon emission abatement, some researchers and policy makers have cast their focus on demand side carbon abatement potentials. This paper addresses the problem of carbon flow calculation in power systems and carbon obligation allocation at demand side. A directed graph based method for tracing carbon flow is proposed. In a lossy network, matrices such as carbon losses, net carbon...
This paper presents three alternatives to database adequacy aiming at on-line dynamic security assessment. Usually, on-line data available at the control centers are not prepared to be directly used in dynamic simulations due to discrepancies between power system data models used in EMS' databases and power system analysis software (off-line). Challenges and requirements of such adequacy are initially...
This paper presents an alternate iterative method to perform AC/DC optimal power flow (AC/DC OPF) calculation considering wind farm integration. Firstly, an original AC/DC OPF model considering wind farm integration is constructed. Then, according to the decoupling theory in the alternate iterative method, the decoupling optimization model of AC/DC OPF model is derived, where the high voltage direct...
Power system contingency screening is aimed at detecting potential threats, such as tripped transmission lines, to support secure operation of power systems. The growing penetration of intermittent-renewable resources into the power system challenges the traditional paradigm of contingency screening. One particular concern is that different renewable-generation profiles may lead to changing severe...
The integrated energy systems (IESs), composed of deeply interdependent electric power systems (EPSs) and natural-gas systems (NGSs), are expected to play an important role in the transition to low-carbon sustainable energy systems. To facilitate the security assessment of IESs, this paper initially proposes the concept of IES security region. First, The security region of the IES is defined as a...
This paper proposes a cascading outages model which captures power system operations, protections, automatic regulations, and remedial action schemes. It is based on linear implicit AC PF, which provides a tradeoff between computationally expensive AC PF and approximate DC PF. Combinations of several types of failures and interactions in blackouts are represented, i.e., cascading line overloads, large...
With higher shares of fluctuating electricity generation from renewables, new operational planning methods to handle uncertainty from forecast errors and short-term fluctuations are required. In this paper, we formulate a probabilistic AC optimal power flow where the uncertainties are accounted for using chance constraints on line currents and voltage magnitudes. The chance constraints ensure that...
The intermittent wind power will impact system operation cost, and voltage profile as well. Voltage profile can be enhanced by implementing energy storage system. Thus the optimal operation of storage devices under wind energy system is of great interest. In this paper, the uncertainty of wind power is tackled by scenario-based approach, and then the optimization problem becomes deterministic under...
Security-constrained optimal power flow (SCOPF) is a vital analysis tool in power system operations and electricity markets. This paper presents a comparative study for OPF and SCOPF between two packages: a nonlinear programming algorithm in MATLAB and a successive linear programming in PowerWorld Simulator. Different OPF/SCOPF cases are implemented in the two packages and the results are compared...
Climate change can easily affect renewable energy power output, and the uncertainty of renewable generation may cause serious influence on the power grid. This paper proposes a novel optimal generation dispatch algorithm to compensate for the fluctuations in power outputs of renewable energy resources. The proposed method helps reduce bus voltage variation and improves the ability of the power system...
This paper proposes a new approach for finding the minimum number of post-contingency corrections to relieve overload. The security-constrained optimal power flow (SCOPF) problem with AC power flow constraints can be formulated as mixed integer nonlinear programming (MINLP), which is an NP-hard problem. A two-stage approach—screening and detailed analysis—is utilized to solve the non-convex MINLP...
Unit Commitment and Economic Dispatch (UCED) with combined cycle (CC) units and AC power flow is an important problem to be solved by ISOs. The problem is difficult because of complicated transitions in CC units and highly non-linear AC power flows. Currently, to solve the problem, transitions among CC states are simplified and AC power flow is approximated with DC power flow. However, the resulting...
This paper proposes an approach for estimating dynamic equivalents retaining the oscillatory modes through an optimal formulation. This approach defines equivalent generators for representing an external area while preserves the study area. The optimal formulation estimates the corresponding parameters of the equivalent generators, minimizing the difference between the main inter-area modes for the...
Distributed DC optimal power flow (DC-OPF) is vulnerable to malicious cyber attacks due to the absence of a control center. In our previous work, we demonstrated a data integrity attack can manipulate the power dispatch result of distributed DC-OPF by compromising the distributed controller on a bus and modifying the information being sent to the neighboring buses. This vulnerability, in turn, could...
Uncertainty and variability are the inherent factors in modern power systems with increasing number of intermittent power resources such as wind and solar integration. This paper presents a novel probabilistic approach to evaluate the power grid with Fault Ride-Through consideration of the wind generation. Low Voltage Ride-Through regulation applied in China grid is investigated in this paper. Critical...
This paper describes under frequency based islanding scheme of the Rawatbhatta Atomic Power Plant (RAPP) situated in Rajasthan. The islanding power system consists of seven generators having total 780 MW generation capacity. On the basis of simulation studies, under frequency based islanding scheme have been designed. Under frequency based islanding relays are placed at interconnecting points. Further...
Adaptive re-configuration and islanding of micro-grids, based on the frequency deviations are attempted in this paper. The proposed technique improves the reliability of autonomous micro-grid under contingencies through adaptive control. Also concept of domains and commons of the distributed generators present in the micro-grids have been used in the proposed methodology. This algorithm is found to...
Due to world wide restructuring of electric supply industry, assessment and allocation of wheeling prices among transmission users has become a crucial task. Wheeling prices are supposed to be distributed over transmission users. Allocation of wheeling prices means determination of distribution of wheeling prices among transmission users and this depends upon the contribution of each user in total...
The extension of Transmission Locational Marginal Cost Prices (LMP) to Distribution node LMPs, or DLMPs, is a prerequisite for efficient demand response that may support significant integration of Renewables. AC load flow and non-linear distribution cost modeling needed to this end, render centralized market clearing Algorithms intractable, with Distributed Proximal Message Passing (PMP) Algorithms...
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