Question

Transformerless Photovoltaic Inverters [Total marks =10 Consider the transformerless inverter SB5000TL being connected to the 4.5kWp array where all exposed conductive parts of the array are bonded together, but are left disconnected from installation earth. A person with body resistance of 470 Q (current path hand to hand) touches the PV array frame with one hand and is well connected to installation earth with the other (a) Sketch a circuit diagram modelling the scenario and estimate the range of leakage currents the person can be exposed to in this scenario. List your assumptions. (5 marks) (b) List factors which influence the magnitude of the leakage current. (2.5 marks) (c) Discuss leakage currents in this scenario with regards to perception threshold, safety and earthing in transformerless PV systems. (2.5 marks)

Answer 1

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