Stability of Power Systems
The Name of the Class (Course)
The Name of the School (University)
The City and State where it is located
Date of Submission
Stability of Power Systems
Power systems are studied under the branch of engineering known as power (systems) engineering. The subfield is concerned with the study of how electric power is generated, transmitted, distributed, and utilized. It also analyzes the electrical and electronics devices and gadgets that are connected to the power systems to assist in their functioning. Such devices include motors, transformers, and generators. Such devices offer ...view middle of the document...
According to Machowski, Bialek and Bumby (2008, n.p.), when a power system is subjected to a disturbance that could otherwise be described as transient its stability changes. The change is proportional to its initial operating condition, as well as the nature of the disturbance causing the change in stability. The magnitude of the disturbances ranges from small to large.
Minor modifications are experienced in the form of changes in the size of the load. Systems that are capable and efficient adjust to such changes to ensure that it retains its optimal performance. Such systems operate with a right index under such changes and conditions. They meet the load demand successfully. They are also capable of surviving several disturbances that might be severe in nature. Serious disturbances include short-circuits on transmission lines or the loss of large generators.
The stability of a power system can be established when a transient disturbance is applied to it. If it is stable, it reaches a new level and state of equilibrium, and the entire system remains intact practically. The proper situation of the system is restored by the use of human operators and the application of automatic controls. A run-down situation or run-away is experienced if the system is unstable. Instability is caused by such occurrences as decreasing voltages in the bus progressively or increasing the angular separation and distance between the rotors of a generator. If the unstable condition is not rectified fast enough, it could result in cascading outages. Persistent cascading outages may lead to the shut-down of a portion or entire portion of the power system (Machowski, Bialek and Bumby 2008, n.p.).
Much of the equipment is involved in the response of a power system to disturbances. For instance, variations in the speed of the rotor of the machine, power flows, and network bus voltages are caused by a fault on a critical element of the system. These parameters of the system occur when the key component is isolated by protective relays. The regulators of the transmission and generator voltages are actuated by the variations in the voltage. The prime mover governors are then actuated by the changes in the speed of the generator. The individual characteristics of the frequencies and voltages determine the extent to which the variations and changes affect loads of the power system.
There are also some devices that are used to protect special equipment in power systems from disturbances and changes in their parameters. Such devices respond to changes and variations in the variables of the system (Pavella, Ernst and Ruiz-Vega 2000, p. 79). As such, they affect the performance of the power system. Modern power systems are characterized by their incorporation of high-order multivariable processes. As such, their performances are affected by numerous devices that have varied characteristics and response rates. Consequently, the manner in which instability occurs in power...