Submarine cable system and a switching method thereof

A switching method for a system, the system comprising:

• a first submarine cable circuit branch and a second submarine cable circuit branch arranged in parallel between an onshore Bulk Supply Point (BSP) and an offshore BSP, the first and second submarine cable circuit branches each including a first circuit breaker, a submarine cable circuit, and a second circuit breaker connected in series, a first line reactor of which one end is grounded and another end is connected between the submarine cable circuit and the first circuit breaker, and a second line reactor of which one end is grounded and another end is connected between the submarine cable circuit and the second circuit breaker;
• and a first bus reactor circuit and a second bus reactor circuit arranged in parallel and connected to the onshore BSP, each including a bus reactor and a third circuit breaker connected in series, the method comprising:
• determining a submarine cable circuit branch to be energized;
• determining a bus reactor related to the submarine cable circuit branch to be energized;
• adjusting tap position of the determined bus reactor to reduce a load of the determined bus reactor;
• adjusting tap positions of the first and second line reactors in the submarine cable circuit branch to be energized to reduce a load of each of the first and second line reactors;
• energizing the submarine cable circuit in the submarine cable circuit branch to be energized;
• and
• immediately after energizing the submarine cable circuit, readjusting the tap positions of the first and second line and the determined bus reactor in the energized submarine cable circuit branch such that voltage levels within the energized submarine cable circuits are acceptable.