本論文提出一應用於放電加工機且具備能量回收功能、操作於連續導通模式之四相式電流源電路。因放電加工機所需之加工電流為脈波式電流，故電流源電路之輸出電流上升速率為重要之考量因素。在不改變電感值的情形下，應用錯相式技術可以增加輸出電流之上升速率。
本論文所提出之能量回收機制提供電感器所儲存之能量一釋放路徑。當放電加工進行當中時，放電間隙可以視為一個具低電阻值的電阻器。但當放電電流截停或發生斷弧時，此放電間隙即呈現高阻抗狀態。如果此時電感器仍儲存有能量，放電間隙電壓將會因為電感電流無法續流而急遽升高進而使電路損壞。本論文所提出之能量回收機制可將電感器上儲存之能量回送至輸入端之電容器，使其可再次被利用，同時解決電感電流續流的問題。
由實驗結果可知，所提出電路的輸出電流可以被調節，同時具備高的輸出電流上升速率。此外，從實驗結果之波型可以發現，本論文所提出之能量回收機制提供電感器所儲存之能量主要釋放路徑，確能達到預期的效果。

This thesis presents the interleaved four-phase buck-based current source in continuous conduction mode with proposed energy-recovery scheme for the electrical discharge machine. A pulse output current is required in the discharge machining. Therefore, the output current slew rate of the current source is of concern. With the use of interleaving technique, the output slew rate of the buck-based current source can be improved with the same inductance value.
The proposed energy-recovery schemes provide the path for the inductor to release its stored energy. When discharge occurs, the gap behaves as a resistor with low resistance. However, the gap reverts to the high impedance state provided by the dielectric when the machining current is off. The energy stored in the inductor is not able to release due to the gap in high impedance state thus induces high di/dt, which can damage the circuit. With the proposed energy-recovery schemes, the energy stored in the inductor can be recovered to the input capacitance to avoid high di/dt.
The experimental results show that the average output current can be regulated and the output current slew rate is high. The experimental results also validate that the proposed energy-recovery schemes provide the path for the inductor to release stored energy when the output current is off.

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