As shown in the single line diagram in an industrial facility, it is fed from a 10

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Question:

As shown in the single line diagram in an industrial facility, it is fed from a 10 kV medium voltage (MV) network via a three-phase transformer with a nominal power of 500kVA and a voltage of 10/0.4kV. As a transformer, it can be overloaded up to 1.2 times its continuous nominal power and is protected by overload corrosion. .The return current of the overcurrent current is 80% of the operating current. The overcurrent operation is a snapshot operation and the command time is extended by a time operation. The time delay unit is set to 10 seconds. 3 loads are fed from the industrial location, 0.4 kV low voltage (LV) bus, and the characteristics of the loads and the time they are active within a 5-minute period are explained in the table below. According to this,

a) Calculate the nominal current value (LV and MV) drawn by each load and divide it into the Table. Also, plot the operation of the total load flow in the past by the OG for 5 minutes on your given graph.

b) Calculate the current value (working current) and the return current at which the overcurrent current will be adjusted to protect until the end in case of using more than 1.2 times the rated power of the transformer.

c) Determine the opening moment of the surrounding and the times that can energize this facility, taking into account the working current of the movement and the return currents according to the load change change you drew in section-a-.