Analisys of complex hospital electrical systems

The construction of a large hospital complex requires a careful analysis of electrical loads so as to ensure reliability and availability of the service even under critical conditions. In addition, power systems, especially complex hospital electrical systems, have numerous nonlinear loads, which significantly inflict power quality (PQ) problems and the purity of the waveform of supplies is lost. Voltage sag and swell can cause sensitive equipment to fail, shutdown and create a large current unbalance. These effects can incur a lot of expensive from the customer and cause equipment damage. So, in order to provide uninterrupted power to the hospital services and prevent equipment damage with varying voltage level and frequency, the correct distribution of active and reactive powers must be well-know. For this purpose, load flow analysis on medium and low voltage networks allows to determine the voltage profiles in all buses of the system and consequently the active and reactive power flows and the short-circuit currents in the various branches. This paper presents an approach method to the design of hospital electrical systems starting from the classification of electrical loads, from the topological network definition and load flow calculations in order to ensure the correct distribution of active and reactive powers and a real balance in terms of investment and operating costs. Significant variations in voltage beyond the limits are due to large reactive power flows and harmonics on the network, which can cause, in addition to considerable energy losses, the loss of voltage. Highly unbalanced electrical loads due to the use of recurrently intermittent electromedical equipment can cause unpredictable behaviors in the network, increasing the risk of damage to the most sensitive equipment and unplanned and unforeseen interruptions. This paper will be very useful for engineers, technicians and designers because it can be a tool for setting up a good electrical design project.