Systems and methods for providing power for plasma arc cutting

Patent metadata

Field	Value
Publication number	US-10610953-B2
Application number	US-201715486257-A
Country	US
Kind code	B2
Filing date	Apr 12, 2017
Priority date	Apr 12, 2016
Publication date	Apr 7, 2020
Grant date	Apr 7, 2020

Abstract

A plasma cutting system includes a plasma torch having a head, and a housing. A power supply is disposed within the housing and is in communication with the plasma torch. The power supply is configured to provide an output current for generating and maintaining a plasma cutting arc by the plasma torch, and includes a control processor in communication with a plurality of autonomous switching circuits via a multi-node communications bus. Each of the autonomous switching circuits includes a microcontroller configured to control the generation of a portion of the output current based on messages received from the control processor, monitor operating parameters of the autonomous switching circuit, and modify a control parameter of the autonomous switching circuit independent of and asynchronous to the other autonomous switching circuits of the plurality of autonomous switching circuits when one or more of the operating parameters exceeds a predetermined threshold.

First claim

What is claimed is:

1. A plasma cutting system comprising:
a plasma torch comprising a head;
a housing; and
a power supply disposed within the housing and in communication with the plasma torch, the power supply configured to provide an output current for generating and maintaining a plasma cutting arc by the plasma torch, the power supply including:
one or more control processors; and
a plurality of autonomous switching circuits in communication with the one or more control processors via a multi-node communications bus, wherein each of the plurality of autonomous switching circuits comprises a unique identifier, each of the plurality of autonomous switching circuits including a microcontroller configured to:
control the generation of a portion of the output current based on one or more messages received from the one or more control processors;
monitor one or more operating parameters of the autonomous switching circuit; and
modify a control parameter of the autonomous switching circuit independent of and asynchronous to the other autonomous switching circuits of the plurality of autonomous switching circuits when one or more of the operating parameters exceeds a predetermined threshold,

wherein operation of an autonomous switching circuit of the plurality of autonomous switching circuits is enabled or disabled based on a value of its unique identifier.

2. The plasma cutting system of claim 1 further comprising a plurality of transmission line termination resistors connected between the plurality of autonomous switching circuits and the one or more control processors.

3. The plasma cutting system of claim 2 wherein the set of transmission line termination resistors is positioned at distal ends of the multi-node communications bus or at a common connection node of the multi-node communications bus.

4. The plasma cutting system of claim 1 further comprising a control board disposed within the housing, the control board comprising the one or more control processors and a connector associated with the multi-node communications bus.

5. The plasma cutting system of claim 1 wherein each microcontroller is a Digital Signal Processor (DSP).

6. The plasma cutting system of claim 1 wherein the multi-node communications bus comprises a multi-drop topology in which the one or more control processors are connected in parallel to the plurality of autonomous switching circuits.

7. The plasma cutting system of claim 1 wherein the one or more operating parameters comprise at least one of a DC voltage, a temperature of an autonomous switching circuit, and a current.

8. The plasma cutting system of claim 1 wherein each microcontroller is further configured to monitor the one or more operating parameters in real time.

9. The plasma cutting system of claim 1 wherein each microcontroller is further configured to:
detect one or more of a single-phase fault or an over-load current fault; and
modify a control parameter of the switching circuit independent of and asynchronous to the other autonomous switching circuits of the plurality of autonomous switching circuits based on the fault; and
provide an indication of the fault to the one or more control processors.

10. The plasma cutting system of claim 9 wherein the indication of the fault is provided to the one or more control processors in one or more messages transmitted via the multi-node communications bus.

11. The plasma cutting system of claim 1 wherein the multi-node communications bus is configured to support at least one of Controller Area Network (CAN) protocol, CANOpen protocol, Ethernet for Control Automation Technology (EtherCAT) protocol, DeviceNET protocol, or SERCOS protocol.

12. The plasma cutting system of claim 1 wherein the one or more control parameters comprise a frequency of a pulse wave modulated (PWM) signal, a duty cycle of a PWM signal, a timing signal for plasma arc ignition, and a shutdown signal.

13. The plasma cutting system of claim 1 wherein each of the plurality of autonomous switching circuits generates an equal portion of the output current.

14. The plasma cutting system of claim 1 wherein at least two of the plurality of autonomous switching circuits generate a different portion of the output current.

15. A plasma cutting system comprising:
a plasma torch comprising a head;
a housing; and
a power supply disposed within the housing and in communication with the plasma torch, the power supply configured to provide an output current for generating and maintaining a plasma cutting arc by the plasma torch, the power supply including:
one or more control processors; and
a plurality of autonomous switching circuits in communication with the one or more control processors via a multi-node communications bus, wherein each of the plurality of autonomous switching circuits comprises a unique identifier, each of the plurality of autonomous switching circuits including a microcontroller configured to:
control the generation of a portion of the output current based on one or more messages received from the one or more control processors;
monitor one or more operating parameters of the autonomous switching circuit; and
modify a control parameter of the autonomous switching circuit independent of and asynchronous to the other autonomous switching circuits of the plurality of autonomous switching circuits when one or more of the operating parameters exceeds a predetermined threshold,

wherein the unique identifier of an autonomous switching circuit of the plurality of autonomous switching circuits is based on one or more of (i) a physical location of the autonomous switching circuit within the housing, (ii) a key installed on the autonomous switching circuit, (iii) DIP switch settings, or (iv) one or more jumpers installed on the autonomous switching circuit.

16. A plasma cutting system comprising:
a plasma torch comprising a head;
a housing; and
a power supply disposed within the housing and in communication with the plasma torch, the power supply configured to provide an output current for generating and maintaining a plasma cutting arc by the plasma torch, the power supply including:
one or more control processors; and
a plurality of autonomous switching circuits in communication with the one or more control processors via a multi-node communications bus, each of the plurality of autonomous switching circuits including a microcontroller configured to:
control the generation of a portion of the output current based on one or more messages received from the one or more control processors, wherein the one or more messages received from the one or more control processors comprise a setpoint for a current reference of the autonomous switching circuit;
monitor one or more operating parameters of the autonomous switching circuit; and
modify a control parameter of the autonomous switching circuit independent of and asynchronous to the other autonomous switching circuits of the plurality of autonomous switching circuits when one or more of the operating parameters exceeds a predetermined threshold.

17. The plasma cutting system of claim 16 wherein the setpoint corresponds to a profile relating gas pressure and time during one of a critical ramp-up period, a steady state period, or a ramp-down period.

18. A plasma cutting system comprising:
a plasma torch comprising a head;
a housing; and
a power supply disposed within the housing and in communication with the plasma torch, the power supply configured to provide an output current for generating and maintaining a pla

Assignees

• Hypertherm Inc

Inventors

• Chin Wayne
• Kamath Girish R
• Leblanc Norman
• Passage Christopher S
• Selmer Shane M

Classifications

• B23K10/00

  Welding or cutting by means of a plasma · CPC title

• B23K10/006 Primary

  Control circuits therefor · CPC title

• H05H2001/4682

  Electricity · mapped topic

• H05H1/36 Primary

  Circuit arrangements (H05H1/38, H05H1/40 take precedence) · CPC title

• H05H2242/22

  DC, AC or pulsed generators · CPC title