INSULATION TYPE BIDIRECTIONAL DC/DC CONVERTER

PROBLEM TO BE SOLVED: To provide an insulation type bidirectional DC/DC converter which reduces a period in which power cannot be transmitted in a predetermined cycle, when transmitting power in a direction from a secondary side of a transformer to a primary side.SOLUTION: The present invention relates to an insulation type bidirectional DC/DC converter 1 comprising a control circuit 5 by which when transmitting power in a direction from a secondary side of a transformer 3 to a primary side, in a case where a voltage ratio n(=VH/VL) of a first voltage VH and a second voltage VL is equal to or more than a determination value J(=1/(1+L1/2 Lm)) that is calculated by using inductance L1 and excitation inductance Lm (in the case of n≥J), a first period in which a first switch element 15 is conducted and a second period in which a second switch element 16 is conducted after the lapse of the first period is calculated in such a manner that a period ratio dn (=first period/second period) of the first period and the second period becomes greater than a determination value dJ(=n(1+L1/2 Lm)-1), and the first switch element 15 and the second switch element 16 are controlled.SELECTED DRAWING: Figure 1 【課題】トランスの二次側から一次側の方向に電力を伝達する場合に、所定周期において電力が伝達できない期間を削減する絶縁型双方向ＤＣ−ＤＣコンバータを提供する。【解決手段】トランス３の二次側から一次側の方向に電力を伝達する場合、第一の電圧ＶＨと第二の電圧ＶＬの電圧比率ｎ（＝ＶＨ／ＶＬ）が、インダクタンスＬ１と励磁インダクタンスＬｍとを用いて算出した判定値Ｊ（＝１／（１＋Ｌ１／２Ｌｍ））以上（ｎ≧Ｊ）である場合、第一のスイッチ素子１５を導通させる第一の期間と、第一の期間の後に第二のスイッチ素子１６を導通させる第二の期間との期間比率ｄｎ（＝第一の期間／第二の期間）が判定値ｄＪ（＝ｎ（１＋Ｌ１／２Ｌｍ）−１）より大きくなるように、第一の期間と第二の期間とを算出し、第一のスイッチ素子１５と第二のスイッチ素子１６とを制御する、制御回路５と、を備える絶縁型双方向ＤＣ−ＤＣコンバータ１である。【選択図】図１