Patent ID: 6081434
Filing Date: 2000-06-27
Classification: B60L,H02M,Y02T

Abstract:
An insulation-type DC--DC power conversion unit for converting an electric power between a first DC supply and second DC supply comprising:an insulation transformer having a primary winding and secondary winding;a first input terminal connected to a positive electrode of the first DC supply;a second input terminal connected to a negative electrode of the first DC supply;a third input terminal connected to a positive electrode of the second DC supply;a fourth input terminal connected to a negative electrode of the second DC supply;a reactor connected to said third input terminal;a first switch circuit including a semiconductor switch and a diode which are connected in inverse-parallel between said first input terminal and one end of said primary winding of said insulating transformer,a second switch circuit including a semiconductor switch and a diode which are connected in inverse parallel between said second input terminal and the other end of said primary winding of said insulating transformer;a third switch circuit including a semiconductor switch and a diode which are connected in inverse-parallel between one end of said secondary winding of said insulating transformer and said reactor;a fourth switch circuit including a semiconductor switch and a diode which are connected in inverse-parallel between a node of the third switch circuit and said reactor and the other end of said secondary winding of said insulating transformer;a first diode connected between said first input terminal and said other end of said primary winding, in which a current flows from said second input terminal toward said first input terminal; anda second diode connected between said second input terminal and said one end of said primary winding, in which a current flows from said second input terminal toward said first input terminal;wherein currents flow in said semiconductor switches of said first and second switch circuits from said first input terminal toward said second input terminal;wherein said other end of said secondary winding is connected to said fourth input terminal;wherein current flows in said semiconductor switch of said third switch circuit from said third input terminal toward said secondary winding;wherein current flows in said semiconductor switch of said fourth switch circuit from said third input terminal toward said fourth input terminal; andwherein said one end of said primary winding and said one end of said secondary winding are of the same polarity.