Sliding-mode control for dc-dc converters with constant switching frequency

✍ Scribed by He, Y.; Luo, F.L.

• Book ID: 114450369
• Publisher: The Institution of Electrical Engineers
• Year: 2006
• Tongue: English
• Weight: 237 KB
• Volume: 153
• Category: Article
• ISSN: 1350-2379
• DOI: 10.1049/ip-cta:20050030

✦ Synopsis

A new approach implementing the sliding-mode controller is proposed for dc -dc converters. The equivalent control input is used as the system control input, which results in a duty cycle regulation control system. As designed, equivalent control input is maintained at a value between 0 and 1, similar to the desired duty cycle value. Thus, constant switching frequency can be achieved under changes of state conditions. Two sliding-mode controllers based on this method are designed for positive output elementary Luo converter. Traditional small-signal analysis is applied to study the close-loop system performance under proposed approach. Audiosusceptibility, control-to-output transfer functions and output impedance are derived on the basis of the small-signal model. It is shown that the proposed sliding-mode control approach retains the advantages of traditional sliding-mode control, as well as achieve constant switching frequency, which is decided by the input saw-tooth waveform. Results of the experiment are reported for both controllers and they verify the theoretical analysis.