Abstract: The present disclosure pertains to the field of power electronics technologies, and provides a grid-connected control method and system for a grid-forming converter without a grid-side voltage sensor. The grid-connected control method includes: performing coordinate transformation on a phase of a three-phase capacitor voltage sampled by a phase-locked loop (PLL) to obtain a first phase; in response to control of a first pulse width modulation (PWM) pulse signal, introducing a reference phase, and performing negative feedback regulation on a difference between the reference phase and the first phase to obtain a second phase; and in response to control of a second PWM pulse signal, performing a modulo operation on a difference between the reference phase and the second phase to obtain a third phase, where the third phase is used to replace a phase of the PLL to perform coordinate transformation of a system.

Abstract: The present disclosure pertains to the field of power electronics technologies, and provides a grid-connected control method and system for a grid-forming converter without a grid-side voltage sensor. The grid-connected control method includes: performing coordinate transformation on a phase of a three-phase capacitor voltage sampled by a phase-locked loop (PLL) to obtain a first phase; in response to control of a first pulse width modulation (PWM) pulse signal, introducing a reference phase, and performing negative feedback regulation on a difference between the reference phase and the first phase to obtain a second phase; and in response to control of a second PWM pulse signal, performing a modulo operation on a difference between the reference phase and the second phase to obtain a third phase, where the third phase is used to replace a phase of the PLL to perform coordinate transformation of a system.