No abstract

In recent years, wireless power transfer has been a popular research topic because it allows both static and dynamic charging without using cables, thus easing the process for the user. However, achieving high efficiency and desired power corresponding to the load at any time is important. Communication between sides is often used, but sometimes its operation is not guaranteed because of harsh environmental conditions or malfunctioning. This paper addresses this problem by proposing a novel yet simple control strategy. It consists of simultaneous regulation of both power and efficiency by the secondary side alone, without communication with the primary side. When the primary side is not manipulated, the power is controlled by an AC/DC converter by using a two-mode control. On the other hand, the efficiency is controlled by a DC/DC converter by adjusting the DC link voltage to a reference value related to the maximum wireless transmitting efficiency. In this paper, the control concept as well as the design are provided. The proposed control shows a good trade-off by achieving power regulation capability at the cost of slight reduction in efficiency when compared to the currently existing state-of-the-art control.

No abstract

In recent years, wireless power transfer technology has received considerable attention because of its wide range of applications. Most of the literature focuses on the resistance load or constant voltage load, and the constant power load is almost never considered. The open loop transfer function of a constant power load is unstable, and therefore closed loop stabilization is required. Furthermore, communication between the two sides is often used but it may not be available. In order to stabilize the load voltage without resorting to coordination with the primary side and discontinuous operation causing big voltage transients, this paper proposes a control strategy for only the secondary side using a single converter. It is based on the combination of synchronous rectification and symmetric phase shift, without communication with the primary side. While the primary side is not manipulated, the AC/DC converter regulates the amplitude of the secondary coil voltage and stabilizes the constant power load voltage on the DC side via a simple PI control. In this paper, the control concept, design and stability analysis are provided. The proposed control is verified through experimental results in both static and dynamic scenarios, achieving a controller that is simple to design and has smooth waveforms.