Test circuit applied to state maintenance of two-speed motor of wind power plant

The invention provides a test circuit applied to state maintenance of a two-speed motor of a wind power plant, and the two-speed motor has two working speeds which are respectively a first interval speed and a second interval speed. Wherein the first interval speed is smaller than the second interval speed; the test circuit comprises a touch screen, a control circuit, a frequency converter, two intermediate relays and alternating current contactors KM1, KM2 and KM3. The touch screen is connected with the control circuit, the control circuit is respectively connected with the two intermediate relays and the frequency converter, the two intermediate relays are a low-speed intermediate relay and a high-speed intermediate relay, when the low-speed intermediate relay is closed, the two-speed motor is in a first interval speed, and when the high-speed intermediate relay is closed, the two-speed motor is in a second interval speed; the low-speed intermediate relay is sequentially connected with the KM1 and the frequ