25-08-2017, 09:32 PM
The Bulk Power Supply
The Bulk Power Supply.ppt (Size: 859 KB / Downloads: 196)
INTRODUCTION
Elaborate, complex, interconnection of power components which make up an interconnected power system.
When we talk about reliability and security of power systems, we are interested in what we call “THE BULK POWER SUPPLY SYSTEM”
The part of the network which connects the power plants, the major substations, and the main EHV/HV lines.
Interruptions in the bulk power supply are very serious
- Many users are affected by these interruptions
- They can be costly
They are to be avoided, and much effort is spent to do that
RELIABILITY
Power Systems are built and operated with the following goal:
TO ACHIEVE A RELIABLE and ECONOMIC ELECTRIC POWER SUPPLY.
For the consumer to have a reliable and economic electric power supply, a complex set of engineering analysis and design solutions need to be implemented.
Reliability has two components
Security is the ability of the electric systems to withstand sudden disturbances such as electric short circuits or unanticipated loss of system elements.
Security of a power system refers to the degree of risk in its ability to survive imminent disturbances (contingencies) without interruption of customer service. It relates to robustness of the system to imminent disturbances and, hence, depends on the system operating condition as well as the contingent probability of disturbances. (IEEE TermsDefs-’04)
REQUIREMENTS OF A RELIABLE ELECTRIC POWER SERVICE
Steady-state and transient voltages and frequency must be held within close tolerances
Steady-state flows must be within circuit limits
Synchronous generators must be kept running in parallel with adequate capacity to meet the load demand
Maintain the “integrity” of the bulk power network (avoid cascading outages)
NERC, North American Electric Reliability Corporation:
Mission is to ensure reliability of the bulk power system in North America. They develop/enforce reliability standards; assess reliability annually via 10-year and seasonal forecasts; monitor the bulk power system; evaluate users, owners, and operators for preparedness; and educate, train, and certify industry personnel. NERC is a self-regulated organization, subject to oversight by the U.S. Federal Energy Regulatory Commission & governmental authorities in Canada. It is composed of 9 regional reliability councils & encompasses virtually all power systems in US & Canada. NERC’s activities play an essential role in preventing contingencies and mitigating their consequences.