IEC 60270 Calibration Uncertainty in Gas-Insulated Substations

Partial discharge (PD) measurements in gasinsulated substations (GIS) are tested according to the standard IEC 60270. This “conventional” PD test method applies to electrically small devices. The equipment size increases the resonance, and attenuation, contributing to the total uncertainty. Additionally, when an ultra-high frequency (UHF) sensor...

The Control Stage of a Modular Multilevel Converter-based Arbitrary Wave shape Generator for Dielectric Testing of High Voltage Grid Assets

A Modular Multilevel Converter (MMC)-based Arbitrary Wave shape Generator (AWG) for High Voltage (HV) testing faces challenges in the control hardware to generate kHz-range high-frequency waveforms. Real Time Simulators (RTS) provide a simple way to implement the control of the MMC-based AWG in the FPGA. One of the commercially available RTS...

Three-Phase Medium-Voltage Medium-Frequency Transformer for SST in Green Hydrogen Production

Green hydrogen production uses renewable energies to energise the electrolysers for hydrogen production. The present paper compares possible solutions and configurations of a medium-frequency transformer (MFT) as part of a solid-state transformer (SST) in green hydrogen production applications. The single-phase and three-phase MFTs are compared...

Implementation of Active Damping Control Methodology on Modular Multilevel Converter(MMC)-Based Arbitrary Wave Shape Generator Used for High Voltage Testing

In order to damp the resonance in the MMC-based Arbitrary Wave shape Generator (AWG) used for high voltage testing, an active damping control methodology is proposed in this paper instead of the passive damping with an arm resistor. It is vital to ensure the system’s stability when such an active damping closed loop control is implemented....

Comparison of Pulse Current Capability of Different Switches for Modular Multilevel Converter-based Arbitrary Wave shape Generator used for Dielectric Testing of High Voltage Grid Assets

This article compares the pulse current capability of various Semiconductor (SM) device technologies for Modular Multilevel Converter (MMC)-based High Voltage (HV) Arbitrary Waveform Generator (AWG) for dielectric testing of grid assets to find the most suitable SM device technology which can perform well in generating lightning impulse that...

Analysis of Partial Discharge Behaviour under Staircase-based Sinusoidal Voltage Waveforms

This paper presents a comparison in Partial Discharge (PD) behaviour when an air corona setup is subjected to different waveforms, namely an idealized 50 Hz sinusoidal and staircase-based sinusoidal waveforms near inception voltage and at a higher voltage. In this study, it has been observed that the PD repetition rate and the Phase-Resolved PD ...

Modular Multilevel Converter-based Arbitrary Wave shape Generator used for High Voltage Testing

This paper analyses different design trade-offs for a Modular Multilevel Converter (MMC)-based Arbitrary Wave shape Generator (AWG) used for High Voltage (HV) testing and certification of grid assets such as transformers, switchgear, and cables. Modulation techniques, number of submodules, output voltage levels, arm inductance, and series...

Cable Capacity Enhancement by Utilizing Trapezoidal Voltage Waveform

To avoid installation of expensive new underground cable connections in locations where peak load exceeds existing cable capacity, it is advantageous to transfer more power through a cable than its nominal power capacity, without endangering its reliability. Dynamic current rating of cables is a typical approach that is used to exceed the...