Power conversion apparatus for pulse current

Abstract

The present invention discloses a power conversion apparatus for pulse current suitable for electrical discharge machining. The power conversion apparatus comprises a linear power conversion circuit and a switching power conversion circuit. The linear power conversion circuit offers a fast response to changes in output load and is used to adjust the output voltage. The magnitude or the waveform of the current through the workpiece is adjusted by the power resistor or the power transistor. Then, the switching power conversion circuit supplies the workpiece a stable power to make the power conversion apparatus output a stable pulse current to achieve the goal of high power conversion efficiency, high power density, and small size.

1 . A power conversion apparatus for pulse current, comprising: 
 a linear power conversion circuit, electrically connected to an outer power supply, the linear power conversion circuit supplying a load current and strengthening the dynamic response ability to the sudden change in the load current; and    a switching power conversion circuit, electrically connected to the outer power supply, the switching power conversion circuit strengthening the load current by a phase-shifting technique to make the load current have better dynamic response ability during the sudden change in the load current.    
   
   
       2 . The power conversion apparatus for pulse current according to  claim 1 , wherein the outer power supply is a DC power supply and the outer power supply can be an input power supply for the power conversion apparatus.  
   
   
       3 . The power conversion apparatus for pulse current according to  claim 1 , wherein the linear power conversion circuit is composed of a single circuit.  
   
   
       4 . The power conversion apparatus for pulse current according to  claim 1 , wherein the linear power conversion circuit is composed of a plurality of parallel circuits.  
   
   
       5 . The power conversion apparatus for pulse current according to  claim 4 , wherein the linear power conversion circuit can change the amount of the parallel circuits according to the load current.  
   
   
       6 . The power conversion apparatus for pulse current according to  claim 1 , wherein the switching power conversion circuit is selected from the group consisting of a buck power conversion circuit, a boost power conversion circuit, a buck-boost power conversion circuit, a forward power conversion circuit, a flyback power conversion circuit, a push-pull power conversion circuit, a half-bridge power conversion circuit, an asymmetrical half-bridge power conversion circuit, and a full-bridge power conversion circuit.  
   
   
       7 . A power conversion apparatus for pulse current, comprising: 
 a linear power conversion circuit, electrically connected to an outer power supply, the linear power conversion circuit supplying a load current and strengthening the dynamic response ability to the sudden change in the load current;    a switching power conversion circuit, electrically connected to the outer power supply, the switching power conversion circuit strengthening the load current by a phase-shifting technique to make the load current have better dynamic response ability during the sudden change of the load current; and    a switching DC/AC converter, used for supplying input power, the switching DC/AC converter converting the AC power supplied by the outer power supply into DC power.    
   
   
       8 . The power conversion apparatus for pulse current according to  claim 7 , wherein the outer power supply is an AC power supply, and the outer power supply can be an input power supply for the power conversion apparatus.  
   
   
       9 . The power conversion apparatus for pulse current according to  claim 7 , wherein the linear power conversion circuit is composed of a single circuit.  
   
   
       10 . The power conversion apparatus for pulse current according to  claim 7 , wherein the linear power conversion circuit is composed of a plurality of parallel circuits.  
   
   
       11 . The power conversion apparatus for pulse current according to  claim 10 , wherein the linear power conversion circuit can change the amount of the parallel circuits according to the load current.  
   
   
       12 . The power conversion apparatus for pulse current according to  claim 7 , wherein the switching power conversion circuit is selected from the group consisting of a buck power conversion circuit, a boost power conversion circuit, a buck-boost power conversion circuit, a forward power conversion circuit, a flyback power conversion circuit, a push-pull power conversion circuit, a half-bridge power conversion circuit, an asymmetrical half-bridge power conversion circuit, and a full-bridge power conversion circuit.  
   
   
       13 . A power conversion apparatus for pulse current, comprising: 
 a synchronous-rectifying buck converter with four phases, electrically connected to an outer power supply, the synchronous-rectifying buck converter with four phases modulating the output voltage;    a buck converter with four phases, electrically connected to a discharging electrode, the buck converter with four phases modulating the output voltage;    a plurality of diodes, electrically connected between the synchronous-rectifying buck converter with four phases and the buck converter with four phases, the diodes feeding back the extra inductor voltage; and    a linear power converter, electrically connected to the discharging electrode, the linear power converter supplying the power to a load.    
   
   
       14 . The power conversion apparatus for pulse current according to  claim 13 , wherein the phase angle of the four phases of the synchronous-rectifying buck converter with four phases is 90 degrees.