What parallel redundancy does the power distribution system have

1. What parallel redundancy does the power distribution system have? Increasing reliability // What parallel redundancy does the power distribution system have? Redundancy is a useful method of increasing reliability and optimizing the balance between operating efficiency and expense. In the context of reliability, redundancy means that a system will continue to perform satisfactorily despite the failure of certain components. What parallel redundancy does the power distribution system have? This fault resilience is achieved by providing alternative paths of operation by organizing selected elements of the system in parallel. As a rule, other modes of operation can be obtained: Pending redundancy Active or parallel redundancy N + 1 and 1 + 1 redundancy

2. Pending redundancy Standby redundancy means that another means of performing the function is provided but is inoperative until needed. It is activated if the primary means of performing the function fails. An example of standby redundancy would be the use of a standby generator set in a building to ensure continuity of power in the event of a mains failure. The generator is called only when needed in the event of a power failure. Such a system would not be suitable for a computer system, as data would be lost for the relatively long period of time required to start the backup generator. Active or parallel redundancy In active or parallel redundancy, all redundant units operate simultaneously rather than being turned on when needed. The most obvious approach is to use two components, each capable of supporting the full load, so that if one fails the other takes over – this is referred to as 1 + 1 redundancy . An alternative approach is to split the load among multiple units , each capable of carrying only a fraction of the load and providing a single additional redundant unit – this is referred to as N + 1 redundancy . For very critical loads, several fully calibrated redundant units can be provided. For example, a 1 + 2 redundancy scheme would have two fully rated redundant units supporting the single operational unit and would require all three units to fail before the system fails. In the absence of interruptions, active redundancy is suitable for IT installations. N + 1 and 1 + 1 redundancy The theory of redundancy is that if any component of a system fails, the system will continue to operate because alternate paths are available for the system to operate. In Figure 1, the system will operate with A1 or A2 running. Should component A1 fail , the system will continue to operate. This type of redundancy is called 1 + 1 because 100% redundancy is available. In the system shown in Figure 2 two of the three components are required for the operation of the system and there is a redundant component. In this scenario, the system would be called 2 + 1 . In each case, the first number is the number of components required for the system to function properly and the second number is the number of pending components available. It is possible to have many redundant components which would greatly improve the reliability of the system. However, this would also be costly and in most applications a balance is struck between reliability and cost efficiency.