Power Electronics Assisted Voltage Regulators for Modern Distribution Systems

Step voltage regulator (SVR) has been utilized in the power distribution systems for decades. The induced arc from the conventional SVR tap change and the voltage instability from the renewable energy penetration impose constraints on the conventional SVRs’ lifetime. With more distributed power generation and renewable energy penetration, voltage fluctuation and power generation variation can be observed more frequently in the modern power distribution network.
Motivated by the issues mentioned above, several PE-assisted arcless tap change topologies are proposed to reduce the contact erosion rate of tap changers in SVR. The system efficiency is the same with the conventional SVR in normal operation, while the converter power rating is only 0.3% of the total system power, which also reduces the system cost compared with the full power electronics solutions. Based on the proposed arcless tap change mechanism, a hybrid voltage regulator is proposed. Stepless load voltage regulation is achieved while the tap changer mechanism remains in the system, which helps to promote the upgrade to the existing power distribution systems.