Complex sentence: He made his international debut at the 1948 Winter Olympic Games of St. Moritz, Switzerland, winning the qualifying race for 1500 m, but he was still not selected for the Norwegian team for this distance.
Split into simpler sentences: He made his international debut at the 1948 Winter Olympic Games of St. Moritz, Switzerland. He won the qualifying race for 1500 m, but he was still not selected for the Norwegian team for this distance.