Purpose of Power System Protection free essay sample

Purpose of POWER System protection The purpose of any power system is to generate, transmit, and distribute electricity to the consumer in a manner that is safe, reliable, and economical; both in the short and long term. Under normal operating conditions, the currents, voltages, power, and energy associated with such systems are all matched to meet the system’s design requirements with respect to reliability, quality, safety, and economy. To ensure maximum returns on the large or expensive investments in the components which go to make up the power system and to keep the customers satisfied with reliable (i. e. , adequate and secure) service, the power system must be kept in operation continuously without major breakdowns and consequently without violating the design limits (because of abnormal currents, voltages, or power). This can be achieved in two ways: (i) Implement a system adopting/using components, which should not fail (i. . , failure-free components) and requires the least or nil maintenance to maintain the adequacy and security of supply. We will write a custom essay sample on Purpose of Power System Protection or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page By common sense, implementing such a system is neither economical nor feasible, except for small systems. (ii) Foresee or anticipate any possible/credible effects or failure events that may cause long term shutdown of a system, which in turn may take longer time to bring back the system to its normal course. The main idea is to restrict or minimise the disturbances during such failures or events to a limited area and continue power supply in the balance/unaffected areas. The second approach is the one commonly used in practical power systems. To realise it, special equipment is normally installed to continuously monitor the power system to detect undesired conditions that present a threat to system reliability (adequacy and security) and take (initiate) action to remove the threat from the system with minimal adverse effects (i. e. detect abnormalities that can possibly happen in various sections of a power system, and to isolate affected sections so that the interruption of supply is limited to a localised area in the total system covering various areas and damage to expensive electrical equipment is limited and safety of personnel provided). This special equipment used to detect such possible failures or faults and initiate their removal is referred to as â€Å"protective equipment or device† and the system that uses such devices is termed as â€Å"protection system or scheme†. Thus, the objective of protection in a power ystem is to minimise the risk of damage to equipment, risk of life threat to personnel, and risk of supply interruptions or loss of service to unaffected portions of the system when faults and other abnormal conditions occur. Protective devices do not, therefore, prevent a fault or any other adverse condition from occurring in the system; they only mitigate or avert the consequences of such conditions whenever they occur through quick isolation or removal of the problem. The typical effects or consequences of fault conditions are discussed in the following section. Summary: There are several reasons to use protective devices in power systems:- (i) to provide alarm when measured process or quantity limits are exceeded, thereby allowing operators an opportunity to intervene with corrective actions; (ii) to isolate faulted equipment or circuits from the remainder of the system so that the system can continue to function; (iii) to limit damage to faulted equipment by quickly isolating from the system and hence reducing the duration of the problem; (iv) to minimise the possibility of fire or catastrophic damage to adjacent equipment; (v) to minimise hazards to personnel; and vi) to provide post-fault information to help analyse the root cause.