Ralph Feldman

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HVDC transmission systems are becoming increasingly popular when compared to conventional ac transmission. HVDC voltage source converters (VSCs) can offer advantages over traditional HVDC current source converter topologies, and as such, it is expected that HVDC VSCs will be further exploited with the growth of HVDC transmission. This paper presents a novel(More)
Selective Harmonic Elimination (SHE) is usually the preferred modulation technique for high power converters. When such modulation is used with Current Source Rectifiers (CSR), control of the dc-link current and of the input Displacement Power Factor is typically achieved by adjusting the amplitude and phase of the CSR modulation index. In this paper(More)
A per-phase sub-module capacitor voltage balancing scheme for the Alternate Arm Converter (AAC) is proposed. Leg balancing regulates the sum of sub-module capacitor voltages in a leg to its set-point. Arm balancing regulates each sub-module capacitor voltage to the nominal sub-module capacitor voltage. Additional converter control requirements and the(More)
This paper presents the steady-state analysis of a high power step-up DC-DC converter based three-phase dual active bridge (3DAB) for use as a medium voltage (MV) DC-DC collector of offshore wind farms. An optimization procedure for a high-power medium frequency transformer is explained and moreover, a design of an optimal control phase shift angle is(More)
The use of HVDC power systems for transferring electrical energy across large distances is growing as the mix of energy sources, including renewables, feeding our utility grids evolves. This presentation will consider the range of Power Converter topologies that can be used for these HVDC applications and will look at the advantages and disadvantages of a(More)
A direct online stator winding resistance measurement scheme is proposed as a means to improve standard efficiency tests of polyphase induction machines. To enable resistance measurement a DC current is injected online into the stator winding and response voltages are captured. In experimental tests an unequal number of anti-parallel diodes has been used to(More)
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