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Abstract Large‐scale wind farms are susceptible to oscillations like any other power systems with high penetration of power electronics, whose characteristics of wideband impedance hold the key to resolving this issue. However, due to the high cost of impedance measurements for power systems, computational modelling methods are usually used, accuracy of which is difficult to be verified. This paper proposes a novel AC chopper integrated with active measurement of wideband impedance (AIM‐ACC), which can be slightly modified from the existing energy consuming devices in wind power systems. With the help of the proposed Reversed‐phase Chirp Pulse Width Modulation (RC‐PWM) signal, the AIM‐ACC generates chopper current within a desired wide frequency band, avoiding the spectral shifting effects of sinusoidal voltages. Thus, the impedance characteristics of wind system are obtained by measuring the injected current and its corresponding voltage, with fast excitation time, good controllability and high accuracy. Finally, the verification of an experiment with single‐phase branch and a simulation with the proposed AC chopper in wind power system was carried out for the effectiveness of the proposed method.