Sliding mode and current observer‐based direct power control of dual active bridge converter with constant power load

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.

Predictive discrete‐time sliding mode based direct power control for grid‐connected energy conversion systems

“…Therefore, disturbance compensator/observer/estimator based control design can be of great help for improving the robustness of the control system if parameter variation and external disturbances exist [29][30][31]. Sliding mode disturbance observers/compensators/estimators due to their robustness are very favourable [32][33][34][35]. These solutions can be particularly interesting for voltage unbalanced application, but the stability of control design is often not easy to prove.…”

Sensor-Reduction Control for Dual Active Bridge Converter Under Dual-Phase-Shift Modulation

“…In order to reduce the number of sensors, the unified phase-2 shift control [23], disturbance observer [24], [25], and current observer-based sliding mode control [26] are presented. However, they are highly dependent on the accuracy of model parameters.…”

Dual‐sliding mode control of nine‐switch inverter

“…Sliding mode control (SMC) is recognized as one of the well‐established control strategies suitable for power converters 12‐15 . Sliding mode usually appears in a dynamic system governed by ordinary differential equations.…”

“…Sliding mode control (SMC) is recognized as one of the well-established control strategies suitable for power converters. [12][13][14][15] Sliding mode usually appears in a dynamic system governed by ordinary differential equations. Conceptually, the control input signal is expressed as a function of the control goals, and it switches at a certain frequency.…”