Search

It is challenging to power a large number of gate drivers of the series-connected insulated gate bipolar transistors (IGBTs) in a high-voltage application because multiple isolated power supplies are needed. In this study, a novel wireless power transfer (WPT) system using repeater coils is designed to solve this problem. Every two repeater coils form a repeater unit, which transfers power to one load. With multiple repeater units in the system, multiple loads can obtain power simultaneously. To eliminate undesirable magnetic couplings between these coils, bipolar coils are used and the two bipolar coils in the same repeater unit are placed perpendicularly. It is derived that constant voltage can be obtained for all the loads, which is especially suitable for powering the IGBT's gate driver. Moreover, the variation of one load power will not affect others. The receiving circuit is designed to transform the received power to the DC voltage compatible with the driving circuits. An experimental setup with six loads has been constructed to validate the proposed WPT system. [ABSTRACT FROM AUTHOR]

This paper proposes a long-distance multi-load wireless power transfer (WPT) system with a constant voltage (CV) output for each load. A repeater unit consisting of two bipolar repeater coils is designed to power the load. Multiple repeater units are placed in a line and the power can be transferred from one unit to the next. Each repeater unit corresponds to one load and multiple loads can be powered simultaneously. The two repeater coils in the same repeater unit are placed perpendicularly to eliminate the magnetic coupling between them. In each repeater unit, a compensation capacitor is placed in series with the transmitting coil while two extra compensation capacitors form a series-parallel (SP) structure for the receiving coil. When neglecting the coil's parasitic resistance, the CV characteristics can be obtained, which enables the independent and flexible power control of each load. Moreover, the influence of the parasitic resistances on the system performance is analysed. Such a system is especially suitable for powering the gate drivers in a high-voltage converter where multiple insulated gate bipolar transistors (IGBTs) are connected in series. An experimental setup with six loads is constructed to validate the proposed system. The maximum system efficiency can reach 88.1%. [ABSTRACT FROM AUTHOR]

This article proposes a novel wireless power transfer (WPT) system for multiple loads. Multiple coils are used as power repeaters to enhance the power transfer capability over a long distance and each power repeater corresponds to a load. The inductor-capacitor-capacitor (LCC) compensation method is used for each repeater coil in the system, which ensures load-independent currents flowing through the loads. Thus, flexible power control can be achieved for all the loads without affecting each other. In order to save space, the compensation coil is integrated with the repeater coil to realize a compact design. Bipolar coils are used for both the repeater coil and compensation coil. The undesirable coupling coefficient between the repeater coil and its compensation coil can be eliminated by putting them perpendicularly. The compensation coil is not only used to achieve resonant condition for the system, but also transfers energy to the next repeater coil via the magnetic coupling between them. The operational principle has been explained in detail. An experiment platform with six loads has been built and the experimental results are provided to validate the effectiveness of the proposed WPT repeater system. The maximum efficiency can reach 86.6%. [ABSTRACT FROM AUTHOR]

A novel wireless power transfer (WPT) system is proposed to power the gate drivers in a multilevel converter to achieve a high insulation level. There are two requirements for the proposed WPT system. First, the WPT system should contain multiple outputs, each corresponding to one gate driver. Second, a constant voltage source is needed for each gate driver. For a multiload WPT system, it is challenging but necessary to realize independent power control of each load. To achieve this goal, the repeater unit consisting of two repeater coils is designed to power a load. Many loads can be powered simultaneously by using multiple repeater units together. The LCC-S compensation topology is adopted for the proposed WPT system. Constant voltage outputs are obtained for all the loads when neglecting the coil's parasitic resistance. An experimental platform with six loads was developed to validate the proposed WPT system. [ABSTRACT FROM AUTHOR]

In this paper, a novel long-distance wireless power transfer (WPT) system using repeater coils is proposed to provide power supplies for the driver circuits in high-voltage applications, such as flexible alternative current transmission systems. Different from most of the existing wireless repeater systems where the load is only connected to the last coil and the repeater coils function solely as power relays, in the proposed system, multiple loads are powered by the repeaters. The repeater coils transfer power not only to the subsequent coils but also to the loads connected to them. Dual coil design is proposed for the repeaters with which load-independent characteristics are obtained with a suitable design of coupling coefficients. As a result, the load power can be easily adjusted without affecting each other. Load current characteristics and system efficiency have been analyzed in detail. The power transfer capability of the proposed system is illustrated for different coil quality factors and coupling coefficients. An experimental setup with 10 loads has been built to validate the effectiveness of the proposed long-distance WPT system. The maximum reachable system efficiency is about 84%. [ABSTRACT FROM AUTHOR]

This letter proposes a novel wireless power transfer (WPT) system with repeater coils for multiple loads. Every two repeater coils form a repeater unit where one is used to receive power from its preceding unit and the other transmits power to the subsequent unit. Each load is connected to a repeater unit and multiple loads can be powered with several repeater units. The two coils in the same repeater unit are both bipolar ones, which are placed perpendicularly so that the magnetic coupling between them can be eliminated. In order to obtain independent power control of all the loads, the series-parallel-series compensation method is adopted for each repeater unit. With a proper resonant condition proposed in this letter, the constant load current can be obtained for all the loads when neglecting the coils’ parasitic resistances. An experimental setup has been constructed and the effectiveness of the proposed multi-load WPT system is validated by the experimental. [ABSTRACT FROM AUTHOR]