Welding wire feeder bus control system and method

Abstract

A welding wire feeder includes a wire feed drive and wire feed control circuitry coupled to the wire feed drive to control the drive of welding wire towards the welding application. The welding wire feeder includes power conversion circuitry configured to receive input power and to convert the input power to welding output suitable for a welding application, output voltage sensors configured to measure output voltage, output current sensors configured to measure output current, and control circuitry coupled to the power conversion circuitry and to the output voltage and current sensors. The power conversion circuitry includes power storage circuitry configured to store energy and to discharge at least a portion of the stored energy during an overdraw event. The control circuitry is configured to control the output current during the overdraw event to maintain a stored energy value of the power storage circuitry greater than a desired minimum energy value.

1 . A welding wire feeder comprising:
 a welding wire feed drive configured to drive welding wire towards a welding application;   wire feed control circuitry coupled to the welding wire feed drive and configured to control the drive of welding wire towards the welding application;   power conversion circuitry configured to receive input power and to convert the input power to welding output suitable for a welding application, wherein the power conversion circuitry comprises power storage circuitry configured to store energy and to discharge at least a portion of the stored energy during an overdraw event;   an output voltage sensor configured to measure output voltage of the welding output;   an output current sensor configured to measure output current of the welding output; and   control circuitry coupled to the power conversion circuitry, to the output voltage sensor, and to the output current sensor, wherein the control circuitry is configured to control the output current during the overdraw event to maintain a stored energy value of the power storage circuitry greater than a desired minimum energy value.   
     
     
         2 . The system of  claim 1 , wherein the power conversion circuitry comprises:
 an internal bus comprising power storage circuitry; and   a buck converter coupled to the internal bus and configured to convert bus power from the internal bus to the welding output.   
     
     
         3 . The system of  claim 1 , wherein the overdraw event comprises a short circuit clearing event. 
     
     
         4 . The system of  claim 1 , wherein a duration of the overdraw event is less than approximately 0.3 seconds. 
     
     
         5 . The system of  claim 1 , wherein the control circuitry is configured to determine a net flow of energy relative to the power storage circuitry based at least in part on the output current and the output voltage, and the control circuitry is configured to control the output current based at least in part on a comparison of the net flow of energy to one or more thresholds. 
     
     
         6 . The system of  claim 5 , wherein the one or more thresholds comprises a threshold based at least in part on design limits of the power conversion circuitry. 
     
     
         7 . The system of  claim 5 , wherein the one or more thresholds comprises a threshold based at least in part on the energy stored on the power storage circuitry, a value of the output current, a current ramp rate, a voltage ramp rate, or any combination thereof. 
     
     
         8 . A method of operating a welding wire feeder, comprising:
 receiving an input power signal from a power source;   converting the input power signal to a bus power signal on an internal bus, wherein the internal bus comprises a bus capacitor;   storing energy with the bus capacitor with at least a portion of the bus power signal;   detecting at least one of a stored energy value of the bus capacitor or a bus voltage of the bus capacitor;   converting the bus power signal to a welding output signal, wherein the welding output signal is suitable for a controlled waveform welding process;   converting at least a portion of the stored energy of the bus capacitor to contribute to the welding output signal during an overdraw event, wherein the welding output signal during the overdraw event is greater than the input power signal during the overdraw event; and   controlling the conversion of the stored energy of the bus capacitor to maintain the stored energy value greater than a desired minimum energy value or to maintain the bus voltage of the bus capacitor greater than a protection voltage value.   
     
     
         9 . The method of  claim 8 , wherein the overdraw event comprises a short circuit clearing event, and a duration of the short circuit clearing event is less than 0.3 seconds. 
     
     
         10 . The method of  claim 8 , comprising:
 detecting an output energy flow of the welding output signal;   determining a net flow of energy relative to the bus capacitor based at least in part on the stored energy value of the bus capacitor, the output energy flow, and an input energy flow; and   determining the overdraw event based at least in part on the net flow of energy relative to the bus capacitor.   
     
     
         11 . The method of  claim 10 , wherein the input energy flow is based at least in part on a model of the input power signal. 
     
     
         12 . The method of  claim 10 , comprising detecting the input energy flow from the input power signal. 
     
     
         13 . The method of  claim 10 , wherein controlling the conversion of the stored energy of the bus capacitor comprises:
 determining a sustainability current value based at least in part on the stored energy value of the bus capacitor, the output energy flow, and a predicted duration of the overdraw event; and   reducing a current component of the welding output signal to the sustainability current value.   
     
     
         14 . The method of  claim 13 , wherein the predicted duration of the overdraw event is based at least in part on a pulse waveform of the controlled waveform welding process, a usage pattern, historical data, or any combination thereof. 
     
     
         15 . The method of  claim 10 , comprising:
 comparing the net flow of energy to one or more thresholds, wherein the one or more thresholds is based at least in part on the stored energy value of the bus capacitor, a current component of the welding output signal, a current ramp rate of the current component of the welding output signal, a voltage ramp rate of the welding output signal, or any combination thereof and   controlling the current component of the welding output signal based at least in part on the comparison of the net flow of energy to the one or more thresholds.   
     
     
         16 . The method of  claim 8 , wherein controlling the conversion of the stored energy of the bus capacitor comprises reducing a current component of the welding output signal to a predefined current value. 
     
     
         17 . A system comprising:
 power conversion circuitry configured to receive input power and to convert the input power to an output power waveform, wherein the power conversion circuitry comprises power storage circuitry configured to store energy and to discharge at least a portion of the stored energy during an overdraw event;   an output voltage sensor configured to measure output voltage of the output power waveform;   an output current sensor configured to measure output current of the output power waveform; and   control circuitry coupled to the power conversion circuitry, to the output voltage sensor, and to the output current sensor, wherein the control circuitry is configured to determine a net flow of energy relative to the power storage circuitry during the overdraw event based at least in part on the output voltage and the output current, and the control circuitry is configured to control the output current based at least in part on a comparison of the net flow of energy to one or more thresholds.   
     
     
         18 . The system of  claim 17 , wherein the one or more thresholds comprises a threshold based at least in part on the energy stored on the power storage circuitry, a value of the output current, a current ramp rate, a voltage ramp rate, or any combination thereof. 
     
     
         19 . The system of  claim 17 , comprising a wire feeder, a plasma cutter, an induction heater, a power generator, or a welding power source, or any combination thereof. 
     
     
         20 . The system of  claim 17 , comprising:
 an input voltage sensor configured to measure input voltage of the input power; and   an input current sensor configured to measure input current of the input power, wherein the control circuitry is configured to determine the net flow of energy relative to the power storage circuitry during the overdraw event based at least in part on the input voltage and the input current.