Gain compensation for a full bridge inverter

摘要

An electrosurgical generator and related systems and methods using a gain-compensated full bridge topology. Gain nonlinearity is corrected by applying impedance and phase correction factors to a control loop to achieve a linear gain structure. In embodiments, gain compensation is performed by comparing an RF setpoint signal with a calculated output signal to generate a first error signal. An impedance correction factor is applied to the first error signal to generate a second error signal. The second error signal is processed by a proportional-integral-derivative controller to generate a phase control signal. A phase control correction factor is applied to the phase control signal to generate a corrected pulse width modulation driving signal, which is used to generate PWM driving signals for a full-bridge inverter. One or more sensors provide feedback for comparison with the RF setpoint.

主权项

1. A system for controlling an electrosurgical generator using a gain-compensated full bridge topology, comprising:
a summation unit configured to receive a radiofrequency (RF) setpoint signal and a calculated output signal, and to generate a first error signal corresponding to a difference between the RF setpoint signal and the calculated output signal; an impedance gain compensation unit configured to receive the first error signal and an impedance signal corresponding to a load impedance, and to generate a second error signal by applying an impedance correction calculation to the first error signal; a controller configured to receive the second error signal and to generate a phase control signal; a phase gain compensation unit, comprising:
a phase preprocessing module that is configured to receive the phase control signal and apply a phase gain correction function to the phase control signal to generate a corrected pulse width modulation driving signal; anda pulse width modulation driver configured to generate a first full bridge driving signal and a second full bridge driving signal that is shifted in phase from the first full bridge driving signal by an amount corresponding to the corrected pulse width modulation driving signal; a full bridge inverter configured to receive the first full bridge driving signal and the second full bridge driving signal and generate an electrosurgical output signal having an electrical property corresponding to a difference in phase between the first full bridge driving signal and the second full bridge driving signal; and a sensor circuit configured to sense an electrical property of the electrosurgical output signal and generate a corresponding calculated output signal.