Sliding mode and current observer‐based direct power control of dual active bridge converter with constant power load. (23rd March 2021)

• Record Type: Journal Article
• Authors: Tiwary, Nishit; Naik N, Venkata Ramana; Panda, Anup Kumar; Lenka, Rajesh Kumar; Narendra, Ankireddy
• Is Part Of: International transactions on electrical energy systems. Volume 31:Number 5(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-03-23
• Subjects: constant power loads -- current observer -- direct power control -- dual active bridge -- sliding mode control; Electric power -- Periodicals; Electric power systems -- Periodicals; Electrical engineering -- Periodicals; 621.3
• DOI: 10.1002/2050-7038.12879
• Languages: English
• ISSNs: 2050-7038

Abstract

Summary: This article presents a bidirectional isolated DC‐DC dual active bridge (DAB) converter, with an improved control strategy under constant power load (CPL) conditions. Major applications of DAB are in solid‐state transformers (SSTs), energy storage systems, dc‐microgrid, and electric vehicle, where it feeds other converters, which act as a CPLs. CPLs have negative impedance characteristics, thereby, have a destabilizing effect and impact the dynamics and stability of power converters feeding them. Maintaining the dc‐link stability and obtaining a robust control with enhanced dynamic performance is a significant challenge. This paper proposes a sliding mode control method for DAB feeding CPL in its output dc‐link. A sliding mode controller is designed to employ direct power control and maintain a constant output voltage in dc‐link for various loading conditions. Additionally, to remove the output current sensor, an output current observer is proposed for improving the reliability and decreasing the cost. The proposed method improves the transient performance, with robust control over parameter mismatch when CPL is connected to the dc‐link. The transient performance and output voltage regulation with the proposed control technique are simulated with a 3 kW DAB converter in MATLAB/Simulink environment. Furthermore, the same proposed control scheme is validated experimentally with various loading conditions. Abstract : This article proposes an improved control strategy for a bidirectional isolated DC‐DC dual active bridge (DAB) converter, operating with constant power load (CPL). A sliding mode controller and a current observer are designed to employ direct power control to maintain a constant output voltage in dc‐link for various loading conditions.