This paper discusses the prototype development and testing of a load invariant, high voltage gain DC power supply using inductive power transfer. The developed supply is intended to power the submodules of the CHB based arbitrary waveshape generator for testing high voltage components and materials. Using the Series Parallel topology, a load invariant voltage gain of 15 is obtained from a 350 V input DC Bus, with an efficiency of 88% and a load regulation of 18%. The obtained 5 kV output can conduct DC breakdown of dielectrics with a damping resistor and can test insulation aging, breakdown under high frequency AC.@en

The integration of renewable energy systems into the grid brings new and unique propositions involving the integration of power electronic inverter based solutions into the High Voltage (HV) grid. Thus a need arises to test the HV components with unconventional waveforms which can be satisfied by the Arbitrary Waveshape Generator (AWG). Two such topologies have been shortlisted for the AWG, ie: Modular Multilevel Converter (MMC) & Cascaded H Bridge (CHB). The MMC requires a single insulated DC source while the CHB requires multiple insulated DC sources with isolation.

Developing insulated DC sources using traditional transformers requires oil, epoxy or other complex insulation materials. The insulation requirements are further exacerbated when HV > 5 kV is required at power levels greater than 1 kW. For this reason, Wireless Power Transfer methods are studied in this thesis to develop a DC Power Supply based on Inductive Power Transfer (IPT). The developed supply is capable of conducting DC breakdown tests and high frequency (>100 kHz) AC discharge tests on dielectrics.

The key requirements for developing such a system are Load Invariant Voltage, High Voltage Gain and Soft Switching. Considering these requirements the Series Parallel (S-P) topology is chosen to deliver 1.5 kW at a DC voltage of 5 kV from a 350 V input, with a diode rectifier. Using the Greinacher rectifier, 10 kV DC output is obtained. Different parameters of the developed resonant converter such as coupling coefficient, switching frequency, deadtime and overcurrent protection are analysed to find a suitable configuration for the DC Power Supply. An efficiency of 88% at rated load and load regulation of 18% is achieved for the developed power supply.

For the CHB, a multi-receiver IPT system is desirable to provide multiple isolated DC outputs. A 2-receiver and a 3-receiver IPT system is constructed and their coupling behaviour is studied. A conclusion is drawn that an ”n” receiver system has a coupling coefficient 𝑘𝑛 = √𝑛𝑘1 and accordingly a S-P IPT system can be developed to obtain multiple (n) isolated DC voltage sources.