Easing future low voltage congestion with an AC chopper voltage regulator

Future urban distribution networks are likely to become overloaded, resulting in serious faults, due to a predicted increase in clean energy technologies such as heat pump boilers and electric vehicles. This will significantly increase demand by up to double the present demand levels. As a result, unless changes are made to the low voltage (LV) urban distribution network it will be over-stressed in the future. A possible solution to increase the capacity of the LV distribution network is to use Point of Use Voltage Regulation (PUVR); which increases the line-to-line distribution voltage from 415V to 600V. A key advantage of PUVR is that the present conductors do not need to be replaced, which can be expensive and prohibitive in an urban environment. However, when the 600V supply is received at the end-user it will need to be converted from 345V phase to 230V phase in order to be useable. This can be achieved with a power electronics converter. This paper will discuss two possible converter topologies for this application: the back to back inverter and the AC chopper. To make PUVR as attractive an option as possible the most cost-effective and efficient topology the AC chopper was investigated via creation of a hardware prototype. The AC chopper was found to generate a loss of 1.6% to 2% at an input voltage of 200V peak.