A protection system (114; 200) for connection between a power source (102; 400) and a direct current (DC) ring bus comprising: a passive protection assembly (106; 212) comprising: a first branch comprising a first end and a second end, said first branch including an inductor coupled between said first end and said second end of said first branch; a second branch comprising a first end and a second end, said second branch comprising a diode in series with a resistance coupled between said first end and said second end of said second branch; and a third branch having a first end and a second end, said third branch comprising a diode in series with a resistance coupled between said first end and said second end of said third branch, said first ends of said first branch, said second branch, and said third branch coupled together and said second ends of said first branch, said second branch and third branch coupled together; and a switch assembly (104; 210; 300) coupled to said passive protection assembly (106; 212), characterized in that said switch assembly (104; 210; 300) comprises a bidirectional switch coupled in parallel with an RC assembly comprising a resistor coupled in series with a capacitor , said RC assembly coupled in parallel with said bidirectional switch. a passive protection assembly (106; 212) comprising: a first branch comprising a first end and a second end, said first branch including an inductor coupled between said first end and said second end of said first branch; a second branch comprising a first end and a second end, said second branch comprising a diode in series with a resistance coupled between said first end and said second end of said second branch; and a third branch having a first end and a second end, said third branch comprising a diode in series with a resistance coupled between said first end and said second end of said third branch, said first ends of said first branch, said second branch, and said third branch coupled together and said second ends of said first branch, said second branch and third branch coupled together; and a first branch comprising a first end and a second end, said first branch including an inductor coupled between said first end and said second end of said first branch; a second branch comprising a first end and a second end, said second branch comprising a diode in series with a resistance coupled between said first end and said second end of said second branch; and a third branch having a first end and a second end, said third branch comprising a diode in series with a resistance coupled between said first end and said second end of said third branch, said first ends of said first branch, said second branch, and said third branch coupled together and said second ends of said first branch, said second branch and third branch coupled together; and a switch assembly (104; 210; 300) coupled to said passive protection assembly (106; 212), characterized in that said switch assembly (104; 210; 300) comprises a bidirectional switch coupled in parallel with an RC assembly comprising a resistor coupled in series with a capacitor , said RC assembly coupled in parallel with said bidirectional switch. <EOS>