Rastin Rastgoufard

Steady state voltage stability enhancement using shunt and series FACTS devices

Power systems consist of generation, transmission, and distribution of power to customers. To meet the ever increasing population demand, the power industry has also grown by increasing the number of devices and incorporating highly complex as well as expensive components into the power system. It becomes specifically important to focus on voltage stability analysis of the power system to avoid worst-case scenarios, such as voltage collapse, which may result in huge losses. One of the main causes of voltage collapse is the insufficient availability of reactive power in the system. This can be overcome by adding reactive power sources such as FACTS devices into it. An attempt on enhancing the steady-state voltage stability using FACTS devices has been made in this work. An IEEE 39-bus test system is built using MATLAB and PSAT. FACTS devices such as Static VAR Compensator (SVC), Static Synchronous Compensator (STATCOM), and Thyristor Controlled Series Capacitor (TCSC), are included into the test system as three separate test cases. Continuation power flow analysis is performed on the system with no FACTS included in it and on the three test cases with different FACTS included in it. The output is displayed in the form of P-V curves, loading margin curves, and active and reactive power losses curves. The results obtained are all compared with each other to draw conclusions on the effectiveness of the each of the FACTS devices in improving the static voltage stability of the power system.

Automatic determination of fault current breakpoint locations for personnel protective grounding of distribution and transmission lines

Personnel protective grounding of overhead distribution and transmission lines is a required safety practice involving field personnel using grounding wires to de-energize lines prior to working on the lines. The purpose of this investigation is to create an automatic process that determines the possible fault currents at all locations of transmission lines to help guide field personnel through selection of grounding wires that are appropriate for the level of the fault currents at corresponding locations. When the power system topology changes, the fault currents at different locations of the lines change. The automation updates the information and contributes to safer environment for field personnel. ASPEN OneLiner, a short-circuit analysis program, was used to perform sliding fault analysis - a series of short circuits placed at incremental distances between the two endpoints of a transmission line resulting in a current profile that shows the fault current level as a function of distance along the line. The paper includes a case study that demonstrates practicality of the method for simulation and analysis of power systems.

Sensitivity analysis of synchronous generators for real-time simulations

The purpose of this paper is to investigate the compatibility of generator models in PSS/E (Power System Simulator for Engineering), EMTP (ElectroMagnetic Transient Program), and Hypersim, a platform used for the real time modeling and simulation of power systems. The paper introduces a methodology for the comparison of generator models by performing sensitivity analysis of power system responses to generator parameter changes. The three platforms produce identical outputs in steady state but different responses in dynamic studies, and the methodology outlines steps for finding and changing generator parameters in one platform to best match the response achieved by another platform. A standard IEEE 14 bus system is analyzed under normal steady state and dynamic conditions and under faulted conditions.

Emission trading mechanism for environmental economic generation dispatch

Economic and emission dispatch of a power system is a well-known multi-objective optimization problem. The purpose of this paper is to present a new approach to formulate the problem as a single-objective optimization problem incorporating a practical emission trading mechanism by considering cap-and-trade scheme which is successfully used in USA. The economic and emission dispatch problem is solved by a two-stage optimization process to cope with the cap-and-trade program. In the first-stage, required emission allowances to supply a particular demand is estimated by a pre-dispatching process that takes into account unit commitment and set bid price (BP) of the primary emission market auction. In the second-stage, final dispatch is calculated using unit commitment, primary emission market bid settlement price (BSP), and secondary market price (SMP) of emission allowances. The performance of the proposed dispatching process is validated by a case study on a modified IEEE 30 bus system which includes three cases indicating that the proposed method (PM) provides the optimal combined solution of economic and emission dispatch for electric utilities.