b'12 Partner News Autumn 2022AcademicA prototype HVDC power transmission system using modular multilevel convertersThis project from the University of Leedsa low switching frequency, attaining highMoreover, they ensure zero net power investigates the control strategies for aefficiency and straightforward low-passentering each cell during one power High Voltage Direct Current (HVDC) Powerfiltering. Compared to conventional Voltagefrequency cycle and equalise capacitor Transmission System based on ModularSource Converters (VSC), MMCs offervoltages between cells.Multilevel Converters (MMCs). Due to its cost- scalability and good fault tolerance due to effectiveness over long distances and hightheir multiple redundancies. This project concluded with successful transmission power with minimal losses, HVDClaboratory testing of a layout containing paved the way for a more environmentallyA simulation study of an HVDC system basedeight half-cell converter modules forming friendly transmission system.on MMCs was conducted in this project, buta phase limb. Simulated control schemes due to the large number of power switcheswere implemented in Typhoon Hardware-in-Power converters are critical to HVDCrequired to achieve high voltages, theLoop-604 system, which measures voltagetransmission, with MMC emerging as thecomplexity of the switching control systemor current signals and controls the hardware advanced converter technology. A stack ofbecame a major technical issue. of MMC in real time.half-bridge cells forms MMC, each consisting of a charged capacitor and a set of insulated- Control schemes include output current gate bipolar transistors (IGBTs). control, circulating current suppression control (CCSC) and cell-floating DC capacitor Cell voltages are small compared to ACvoltage balancing control. This allows for the and DC transmission voltages, but stackingadjustment of the current flow to external several cells in series would achieveAC load following appropriate values and high system voltages. This generates areduces the circulating current resulting from relatively smooth multilevel waveform atvoltage discrepancies within each phase leg. Voltage (Blue) and Current (Yellow) output on the Oscilloscope.Diversity and inclusion in techLondon Metropolitan UniversitysShadow Science, Research and Innovation Professor and Director of the Centre forMinister, Chi Onwurah MP. Communications Technology research group, Bal Virdee, was invited to talk at theAt the event Prof Bal Virdee, said: The tech Parliamentary Internet, Communications andsector in the UK has long been a leader in Technology Forum (PICTFOR) in the Housechampioning diversity and inclusion, but of Commons on 17 May 2022.it has a long way to go until we see equal representation. The Covid-19 pandemic has PICTFOR is the All-Party Parliamentaryshone a light on the extent of the digital Group for the technology sector, withdivide in the UK, highlighting the vital Professor Bal Virdee. a purpose to further the understandingneed for equal access to tech hardware, of policy issues affecting the internet,tech opportunities and tech skills. We find communications and technology sectorourselves at a crucial crossroads on the between parliamentarians, industry,road to levelling up the tech divide.consumer groups and academia, and to The tech sector is continuingcontinue to strengthen the UKs position asThe tech sector is continuing to grow, but to grow, but this growth cana leading digital economy. this growth can only be sustained with only be sustained withqualified tech graduates, and lots of them. Chaired by Darren Jones MP, speakersThe shortage of tech graduates is currently qualified tech graduates,included the Shadow Secretary of State forimpacting organisations of all sizes. and lots of them. Women and Equalities, Anneliese Dodds MP, the Chair of the Women and Work APPG,London Met is playing its part in producing Flick Drummond MP and the tech graduates.'