HVDC shunt tap based on three single‐phase half‐bridge series‐connected MMCs operated under 2L modulation

Input‐voltage and output‐current equalization of series‐in parallel‐out three‐phase multi‐module voltage source converter‐based high voltage direct current shunt tap

“…In Allebrod et al, 27 Conventional MMC with parallel legs has been employed for HVDC applications, where it has six arms, where N series‐connected half‐bridge sub‐modules per arm are employed for ( N + 1) level converter. In Hao et al, 28 series‐connected single‐phase H‐bridge MMCs have been used, where this arrangement provides DC‐AC conversion with a lower number of switches compared to the arrangement presented in Allebrod et al 27 In Elserougi et al, 29 an HVDC shunt tap, which is based on series‐connected single‐phase half‐bridge MMCs, has been presented for further decrease of employed semiconductor devices. The involved half‐bridge MMCs in Elserougi et al 29 are also operated under 2L modulation to operate with diminished arm inductors and SMs capacitances which affects positively on the system cost.…”

“…[1][2][3] The small tapping station should satisfy some conditions such as low cost, negligible impact of the main DC-link and no clashes between tap and DC-link controllers. 4 As mentioned before, there are two possible options to tap small amount of power from the power transferred through the HVDC line, namely, parallel-tap [5][6][7][8][9][10] and series-tap. 11,12 The shunt tap valves are rated at the full high DC voltage, which necessitates employment of series-connected IGBTs to implement the high-voltage valve; which makes the shunt tap has higher cost compared to the series tap.…”