Mitigation of current and voltage asymmetry caused by low-carbon technologies using the balancing transformer on low-voltage electricity network

The rapid development of single phase low-carbon technologies causes that an increasing share of photovoltaics (PV), heat pumps and micro-cogeneration (mu CHP) technologies are connected to the low-voltage electricity network. Connecting such low-carbon technologies significantly increase the current and voltage asymmetry, which leads to exceeding statutory limits for phase-neutral voltages and often cause failures of electrical devices. The paper discusses issues related to the phenomenon of current and voltage asymmetry in a typical three-phase four-wire low-voltage electricity network and presents measurements of asymmetry mitigation efficiency using the balancing transformer in two different low-voltage electricity network, supplying consumers and prosumers at one of the Distribution System Operators (DSO) in Poland.