Enovis has filed a patent for a method to cancel the effects of voltage variation in a welding power supply. The method involves rectifying the mains voltage, applying it to a pulse wave modulated (PWM) controlled inverter, detecting the rectified voltage, and setting a maximum duty cycle for the inverter based on the voltage value. The maximum duty cycle can also be determined by the core size or area of the main transformer. GlobalData’s report on Enovis gives a 360-degree view of the company including its patenting strategy. Buy the report here.
According to GlobalData’s company profile on Enovis, Compressed gas storage systems was a key innovation area identified from patents. Enovis's grant share as of September 2023 was 63%. Grant share is based on the ratio of number of grants to total number of patents.
Method for cancelling effects of voltage variation in welding power supply
A recently filed patent (Publication Number: US20230311230A1) describes a method performed in a welding power supply. The method involves receiving a mains voltage at the welding power supply and rectifying it to obtain a rectified voltage. This rectified voltage is then applied to an input of a pulse wave modulated (PWM) controlled inverter. The method also includes detecting the value of the rectified voltage and setting a maximum duty cycle for the PWM controlled inverter based on this value. The PWM controlled inverter is then operated in accordance with the maximum duty cycle.
The patent also claims additional features and methods for the welding power supply. These include controlling the duty cycle for the PWM controlled inverter based on feedback received from an output of the welding power supply. The method further involves applying the output of the inverter to a primary winding of a main transformer of the welding power supply. The maximum duty cycle of the PWM controlled inverter can be set based on a ratio of turns between the primary winding and a secondary winding of the main transformer, a desired output voltage of the welding power supply, or the size or area of a core of the main transformer.
The method also includes sensing the rectified voltage during the startup phase of the welding power supply and during ongoing operations, and re-setting the maximum duty cycle for the PWM controlled inverter based on a new value of the rectified voltage. The value of the maximum duty cycle can be stored in a location accessible to a pulse wave modulation controller that controls the PWM controlled inverter. Additionally, the rectified voltage can be filtered with a capacitor to obtain a filtered version, and the value of the rectified voltage can be detected based on this filtered version.
The patent also describes a power supply that incorporates the above method. The power supply includes a rectifier that receives a mains voltage and outputs a rectified voltage, a PWM controlled inverter powered by the rectified voltage, and a controller that sets the maximum duty cycle for the PWM controlled inverter based on the detected value of the rectified voltage. The power supply can be used for welding or cutting applications.
Overall, this patent presents a method and power supply design that efficiently controls the duty cycle of a PWM controlled inverter in a welding power supply. The method allows for adjustments based on various factors such as the rectified voltage, feedback from the output, and characteristics of the main transformer. This innovation has the potential to improve the performance and reliability of welding power supplies used in various industrial applications.