The invention discloses a power system oscillation control limiter and a system. The oscillation control limiter is used for preventing the locking of a power electronic converter. The oscillation control limiter comprises a signal comparison module, a direct current resistant module and a limiting module, wherein the signal comparison module is used for judging whether an inputted control outputsignal is a direct current signal or not; the direct current resistant module is used for generating a first control reference signal according to the control output signal if the control output signal is a direct current signal and enabling the power electronic converter to operate according to the first control reference signal, and the first control reference signal is zero; and the limiting module is used for limiting the control output signal according to limiting conditions if the control output signal is a non direct current signal so as to generate a second control reference signal andenabling the power electronic converter to operate according to the second control reference signal. The oscillation control limiter can achieve the purposes of improving the output capacity of the power electronic converter and reducing locking influences of the power electronic converter.