The invention discloses a
robust control method and
control system of a direct-current
buck converter, and a direct-current
buck power converter. The method comprises the following steps: S1, acquiring
voltage at two ends of a
capacitor of a converter and current flowing through the
inductor of the converter; S2, respectively calculating values z1(k) and z2(k) of error variables z1 and z2 at a moment k according to the obtained
voltage and current; and S3, setting the duty ratio of the on-off
control signal of the switching tube of the converter as an actual
control variable u, obtaining the value u(k) of the actual
control variable u at the moment k, setting the duty ratio of the on-off
control signal of the switching tube of the converter as u(k), and returning to S1. According to the invention, the control method can effectively solve the problem of
bus voltage oscillation caused by non-linear change of the load so as to stabilize the
power supply voltage, the calculated amount is small, the
algorithm is simple and easy to understand,
robust control is achieved through the combination of the first inequality and the second inequality and the
backstepping method, items needing tobe amplified are amplified slightly, and output oscillation is small.