Power system engineering is the technical discipline applied to designing the electric power system for high power, electric utility applications as well as industrial and commercial power distribution systems. Power management is the engineering aspect of managing the electric loads such that available power sources are not overloaded and power is allocated to the different loads such that the loads are receiving a proper allocation of power. Power management is a major issue with which the computer system designers have to deal but it is equally critical for the electric utility engineers, operators and system planners.
Power management in computer systems and server farms requires a good understanding of the electric power demands in the computer system when the computer system is running different applications. The central processing units (CPU) consume varying amounts of electric power when running different programs. The power demand represented by a disk drive depends on how many read and write operations that are needed. So the total power demand in a computer can vary significantly from one application to another. The engineers designing the power system for a computer must therefore, have good information about the user profiles and understand how the power demands vary depending on hat programs that are used in the computer. Using this information, the power supplies can be sized to meet the total power demands for all applications. This is an economic optimization problem not unlike what power system engineers perform for the high power electric utility system applications.
Utility engineers have to study how the electric loads flow from the generators to the users over transmission and distribution lines. The system ha to operate stably under many different assumed fault or disturbance conditions. In the new deregulated environment, power plants can be connected or disconnected almost at will. Short circuit analysis is used to calculate the short circuit currents at all points of the electric system u8nder different operating scenarios. This is used to determine the required short circuit rating of the equipment but also to set the protective relays used to detect faults and to initiate isolation of the faulted portion of the electric power system. The short circuit data is also used to determine that the coordination between different relays or fuses is proper so that only the minimum faulted area is removed form the system. Improper coordinating can lead to major outages with numerous undesirable consequences.
Commercial and industrial power systems require similar careful studies although in these systems the emphasis might be more on making sure that cables are adequate to serve the intended loads. Power quality is a major issue for industrial and commercial power users. Stand-by or emergency power sources might be required for safety reasons. Reliability studies and failure modes and effects analysis (FMEA) are often performed to identify weak spots in the power system so that costly disturbances of a processing plant or a business enterprise can be avoided.
Exponent engineers and scientists are familiar with power engineering principles and have tools for analysis of power systems of all sizes. Such analytical work is often needed to understand equipment failures, malfunction of protective relaying devices, and to estimate the energy to which a person is exposed when subjected to an arc flash. Our engineers are also well versed in power management aspects of computer systems and has performed design audits of computer systems as a service to the suppliers of computer systems.