Robust H_∞ output feedback control of bidirectional inductive power transfer systems

Abstract

Robust H ∞ output feedback control of bidirectional inductive power transfer systems AKSHYA SWAIN, DHAFER ALMAKHLES, MICHAEL J. NEATH and ALIREZA NASIRI Bidirectional Inductive power transfer (IPT) systems behave as high order resonant networks and hence are highly sensitive to changes in system parameters. Traditional PID controllers often fail to maintain satisfactory power regulation in the presence of parametric uncertainties. To overcome these problems, this paper proposes a robust controller which is designed using linear matrix inequality (LMI) techniques. The output sensitivity to parametric uncertainty is explored and a linear fractional transformation of the nominal model and its uncertainty is discussed to generate a standard configuration for µ-synthesis and LMI analysis. An H ∞ controller is designed based on the structured singular value and LMI feasibility analysis with regard to uncertainties in the primary tuning capacitance, the primary and pickup inductors and the mutual inductance. Robust stability and robust performance of the system is studied through µ-synthesis and LMI feasibility analysis. Simulations and experiments are conducted to verify the power regulation performance of the proposed controller.

Integrated control method for constant output voltage and maximum efficiency tracking of bilateral LCL compensation ICPT system

“…The GSSA method can select any order Fourier coefficients according to the accuracy requirements, which can quickly and accurately describe the steady-state characteristics and transient characteristics of the system state variables, making it suitable for the modelling of ICPT systems [13][14][15]30]. The establishment of the GSSA nominal model is one of the basic steps to obtain a robust controller.…”

“…Therefore, it is necessary to obtain an accurate constant voltage by using closed-loop control methods. As a kind of method to stabilise the output voltage, robust control methods, including H ∞ and μ-synthesis, have received much attention for their superiority in suppressing parameter perturbations, performance to enhance the robustness of the system and greater tolerance for variable parameters [11][12][13][14][15]. Li et al [11] proposed an H ∞ controller based on the LMI algorithm, which can effectively reduce the impact of frequency and load uncertainties.…”

“…Li et al [12] designed a two-degree-of-freedom robust controller because of the influence of load and coupling coefficient variation, and the timedomain performance is considered along with robust performance to ensure better robustness and constant voltage output. In [13][14][15], structural singular value is employed to describe robust stability and robust performance as system indicators, along with the controllers that can make the system meet the output performance index.…”

Dynamic output feedback control for wireless power transfer systems

“…However, the structure of the controlled object needs to be an integral series type by ADRC method [18,19]. Besides, through the researcher's continuous efforts and pursuit, the modern advanced control methods can be applied to practical systems, such as the output feedback control [20], the sliding-mode control [21][22][23], the adaptive control [24][25][26], and the dynamic output feedback control (DOFC) [27][28][29][30]. In Li et al [31,32], for strict-feedback nonlinear systems, the adaptive neural network output feedback optimized control is designed.…”

Single-bit modulator for wireless power transfer system

“…However, one of the issues with WPT systems and CPT systems in particular is the inability to maintain the power flow at a desired level. This is mainly due to the uncertainties arise from load and circuit parameter variations and the operating frequency drifting of the power supply i.e., the operating frequency of the power inverter [10][11][12][13][14]. Hence, proportional-integral (PI) and proportional-integral-derivative (PID) controllers are often implemented to regulate the voltage in order to control power flow between the transmitters and receivers of WPT systems [10,12,15,16].…”