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Technical Paper
Evaluation of Inverter and Cable Losses in Adjustable Speed Drive Applications with Long Motor Leads
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Fig 2a. Inverter output L-L voltage with 100 ft cable.
SIMULATION RESULTS
Analysis have shown an increase in inverter IGBT switching losses due to the use of long cables, and an increase in transient inverter loading (cable charging current). Simulation results (Fig. 2) for a 5 kVA system demonstrate the effect of a long cable on the motor terminal over-voltage (Fig. 2c) and the cable charging current (Fig. 2d).
Fig 2b. Simulated system: 460 V, 5 kVA, 2 kHz ASD system with lumped cable parameters.
Fig 2c. Motor terminal L-L voltage with 100 ft cable.
Fig 2d. Inverter output phase current with 100 ft cable illustrating charging current.