E-beam high voltage switching power supply

• US 5,566,060 A
• Filed: 05/22/1995
• Issued: 10/15/1996
• Est. Priority Date: 04/13/1992
• Status: Expired due to Fees

• Current Assignee: United States Enrichment Corporation (Centrus Energy Corp.)
• Original Assignee: United States Of America As Represented By The Department Of Energy
• Inventors: Lange, Arnold C., Shimer, Daniel W.
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): Berhane, Adolf
• Application Number:
  US08/445,826
• Time in Patent Office: 512 Days
• Field of Search: 363/65, 363/40, 363/79, 363/95, 363/132, 307/43, 307/58, 307/82
• US Class Current: 363/65
• CPC Class Codes: H01J 37/241 High voltage power supply or regulation circuits
• CPC Class Codes: H02H 7/00 Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
• CPC Class Codes: H02M 3/3376 with automatic control of output voltage or current

Abstract

A high-power power supply produces a controllable, constant high voltage put under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules.

Claims

1. Circuit means for generating a ground level voltage feedback signal for controlling the output voltage of one of a plurality of dc--dc converter modules having their outputs connected in series to form a supply output lead, each module including a switching means for producing a pulsating voltage of controlled duty cycle, an inductor means for converting said pulsating voltage into a smooth direct current, an inverter means for producing from said direct current an alternating current through the primary of a transformer, said transformer having at least one secondary winding inductively coupled to said primary winding for producing an output voltage of said module, said circuit means for generating the output voltage feedback signal comprising:

a separate transformer winding inductively coupled with said primary and said secondary for producing an ac voltage whose magnitude is proportional to the dc output voltage of said dc--dc converter module;

rectifier means responsive to said ac voltage produced by said separate transformer winding having a connection with a capacitor for producing a dc voltage on two output lines which voltage is proportional to the dc output voltage of said dc--dc converter module;

current sensing means connected to said supply output lead for producing an output voltage proportional to the current flowing through the output of all of said series connected dc--dc converter modules;

controlled current source means connected across said two output lines for applying the output voltage of said current sensing means to produce a current proportional to the output current of said dc--dc converter module wherein said controlled current source means draws current out of said two output lines to create an accurate simulation of the module output load.

2. A circuit means for decoupling a power supply output from load generated arcs comprising:

a power supply including a plurality of dc--dc converter modules each having two input lines and two output lines, said modules linked in parallel on their input lines and in series on their output lines;

regulating means, provided in each module, for producing a controlled source of direct current;

inverter means for generating a square wave current of alternating polarity from said controlled source of direct current;

transformer means for stepping up an applied voltage and for stepping down said square wave current from said inverter means;

output rectifier and filter capacitor means for rectifying and filtering said square wave current from said transformer;

inductor means disposed in a power supply output line for limiting current rate of change between said plurality of said series connected output lines of said dc--dc converter modules and a supply output line;

resistor damping means connected in parallel with said inductor means, said resistor damping means for reducing oscillation caused by resonance between said inductor and said filter capacitor.

3. An apparatus according to claim 2 wherein said inductor means for limiting current rate of change and said resistor damping means for reducing oscillation, connected in parallel with said inductor means, are inserted in each output line of said plurality of dc--dc converter modules.

4. An apparatus according to claim 3 wherein said plurality of dc--dc converter modules have their output lines connected in parallel.

5. A power supply for producing a controlled high voltage output when operating with rapidly changing loads such as when load arcing is present comprising;

a means for rectifying a source of multiphase ac voltage and for producing an unregulated dc voltage on positive and negative out leads;

a plurality of dc--dc converter modules connected in parallel across said positive and negative dc output leads of said means for rectifying, each of said converter modules including a regulator means for producing a pulsating voltage of controlled duty cycle, an inductor means for smoothing said pulsating voltage into a smooth direct current, inverter switch means for converting said direct current into high frequency square wave current of alternating polarity, transformer means having a primary winding for receiving said high frequency square wave current and for stepping up the applied voltage across said primary winding to a high voltage level across a secondary winding, output rectifier and filter capacitor means for converting the high frequency, high voltage developed across said secondary into a high direct voltage on a positive and negative output lead of a first output rectifier and filter of a first dc--dc converter module connects to the negative output lead of a second output rectifier and filter of a second circuit module such that the dc output voltage produced by all circuit modules are added and the sum of said voltage is developed across a positive and negative output line of the power supply;

output simulator means including a voltage sense winding means inductively coupled with each primary and secondary winding of said transformers in said plurality of dc--dc converter modules and for producing a simulated output voltage proportional to the dc--dc converter module output voltage; and

control means for activating each successive dc--dc converter module in a phased relationship, 360°

/n out of phase with an adjacent dc--dc converter module, where n is the number of dc--dc converter modules in said plurality of dc--dc converter modules, and for sensing in each of said dc--dc converter modules said simulated voltage and including means for regulating said dc voltage as a function of the difference between said simulated voltage and a desired output voltage.

6. A power supply according to claim 5 wherein said plurality of dc--dc converter modules each have their respective output leads connected in parallel.

7. A power supply according to claim 5 wherein each of said plurality of dc--dc converter modules further comprises:

a regulator switching means having a collector lead, a control lead and an emitter wherein said emitter is connected to said negative dc output of said rectifier, said collector is connected to the anode of a free wheeling diode and to a first lead of an inductor;

an inverter means having first and second input leads wherein said first input lead connects to a second input lead of said inductor and said second input lead connects to said free wheeling diode cathode and to the positive dc output lead of said rectifier;

control means for sequentially enabling successive regulator switch means of each successive converter module equally out of phase with an adjacent converter module.