A saturable reactor is like a pipe that electricity passes through. It helps control the flow of electricity. To help understand this imagine a tube with water running through it. That's like electricity running through a saturable reactor. Now if you put a valve on the tube, you can control the amount of water coming out of it. A saturable reactor works the same way. Using the valve, you can control the amount of electricity that passes through the saturable reactor. It helps to smooth large changes in the flow of electricity.