Comparative Study of Voltage and Control Characteristics of Two-Core and Single-Core Step-Up/Down Thyristor-Controlled Phase-Shifting Transformers

The thyristor-controlled phase-shift transformer (TCPST) is an effective means of controlling power flow, exhibiting a simple structure and a long operating life. However, conventional TCPSTs are limited in their ability to regulate the phase-shifting angle, necessitating the matching of the step-up/down transformer to control the amplitude of voltages. Therefore, this paper puts forth two distinct structures of TCPSTs, each of which is capable of regulating both the phase-shifting angle and the amplitude of voltages: the two-core step-up/down thyristor-controlled phase-shifting transformer (TCSUD-TCPST) and the single-core step-up/down thyristor-controlled phase-shifting transformer (SCSUD-TCPST). Moreover, a comparison was conducted between the topology structure and the thyristor-controlled strategies of the TCSUD-TCPST and the SCSUD-TCPST. The coupling relationship and the limitations of the phase-shifting angle and the amplitude of voltages are illustrated, indicating that the SCSUD-TCPST appears to be a more suitable option for power transmission. Furthermore, the considerable static and dynamic characteristics of the TCSUD-TCPST and the SCSUD-TCPST were investigated through the PLECS simulation platform, which was also employed to further verify the aforementioned conclusions.