一個使用自適應調節導通時間來提高功率轉換率的13.56MHz混合模式無線功率接收器

Abstract

電壓型無線功率接收器通過使用耦合線圈，直接轉換無線功率到電池上。如果轉換的電壓高於電池電壓，則這種功率接收器具有較高的功率轉換效率。但是，當這個轉換電壓低於電池電壓，需要一個額外的升壓DC-DC轉換器來提高電壓，這就會使PCE下降。相反，電流型無線功率接收器在低輸入功率下，採用多次共振來累積能量，從而避免使用額外的DC-DC轉換器，從而提高PCE。但是，當輸入功率增加，這種功率接收器的連接損耗增加，從而使PCE下降。因此，為了擴展輸入功率範圍以及提高PCE，混合型無線功率接收器被提出，這種功率接收器結合了電流型以及電壓型的優點。 這篇論文的主題主要分為兩個部分，第一部分提出了一個具有自動控制脈衝寬度以及共振次數的13.56MHz電流模式無線功率接收器。此電路並不同於既有文獻，在保留其同樣的充電原理下，提出了一個新的零電壓偵測器，一個新的零電流偵測器，以及一個自適應調節共振次數控制器。這個零電壓偵測器使用相位偵測器以及數位控制延遲器來實現。這個零電流偵測器使用兩個不同大小的並聯電晶體以及數位控制延遲器來實現。這個自適應調節共振次數控制器使用峰值電壓偵測以及共振次數計數器來實現。 第二部分實現了一個具有自動控制脈衝寬度13.56MHz混合模式無線功率接收器。為了提高在高輸入功率情況下的功率轉換效率，在電流模式無線功率接收器的基礎上加入一個電壓模式的充電路徑。這種無線功率接收器稱為混合模式無線功率接收器。使用一個電流模式的時間控制器以及一個電壓模式的時間控制器分別控制電流模式充電以及電壓模式充電。

Voltage-mode receivers [1-3] are used to convert the wireless power to charge a battery directly by using the coupled coils. A high power conversation efficiency (PCE) is achieved if its converted voltage is larger than the battery one. When the converted voltage is less than the battery one, an additional step-up DC-DC converter will be required which may decrease the PCE. On the contrary, current-mode receivers [4-7] adopt the multiple resonance cycles to accumulate the energy for a low-input power without a step-up DC-DC converter which improves the PCE. However, when input power increases. The conduction loss of the current-mode receiver will be increased for a high input power. Therefore, to extend the input power range and improve the PCE, hybrid-mode receivers [8~10] are presented which combine the advantages of the current-mode and voltage-mode ones. This thesis consists of two parts. The first part implements a 13.56MHz resonant current-mode wireless power receiver using an adaptive pulse width controller and resonant cycle controller to receive the different input power. A new zero voltage switching controller and a zero current switching controller are presented. The new zero voltage controller uses the phase detector and the digital controlled delay line to control the switching timing of the power MOSFETs. The new zero current controller uses the two different size power MOSFETs and the digital controlled delay line to control the switching timing of the power MOSFETs. An adaptive resonant cycle controller uses peak detector sample-and-hold and cycle counter to control resonant cycles. The second part implements a 13.56MHz resonant hybrid-mode wireless power receiver using an adaptive pulse width controller is presented to receive the different input power. For improving PCE at high input power, a voltage-mode charging path is added in current-mode charging receiver. A current-mode timing controller and a voltage-mode timing controller control current-mode and voltage mode charging, respectively.