A Buck-Boost Type Charger with a Switched Capacitor Circuit

Wu, Jinn-Chang,Jou, Hurng-Liahng,Tsai, Jie-Hao The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.1

In this paper, a buck-boost type battery charger is developed for charging battery set with a lower voltage. This battery charger is configured by a rectifier circuit, an integrated boost/buck power converter and a switched capacitors circuit. A boost power converter and a buck power converter sharing a common power electronic switch are integrated to form the integrated boost/buck power converter. By controlling the common power electronic switch, the battery charger performs a hybrid constant-current/constant-voltage charging method and gets a high input power factor. Accordingly, both the power circuit and the control circuit of the developed battery charger are simplified. The switched capacitors circuit is applied to be the output of the boost converter and the input of the buck converter. The switched capacitors circuit can change its voltage according to the utility voltage so as to reduce the step-up voltage gain of the boost converter when the utility voltage is small. Hence, the power efficiency of a buck-boost type battery charger can be improved. Moreover, the step-down voltage gain of the buck power converter is reduced to increase the controllable range of the duty ratio for the common power electronic switch. A prototype is developed and tested to verify the performance of the proposed battery charger.

A Buck-Boost Type Charger with a Switched Capacitor Circuit

Jinn-Chang Wu,Hurng-Liahng Jou,Jie-Hao Tsai 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.1

In this paper, a buck-boost type battery charger is developed for charging battery set with a lower voltage. This battery charger is configured by a rectifier circuit, an integrated boost/buck power converter and a switched capacitors circuit. A boost power converter and a buck power converter sharing a common power electronic switch are integrated to form the integrated boost/buck power converter. By controlling the common power electronic switch, the battery charger performs a hybrid constant-current/constant-voltage charging method and gets a high input power factor. Accordingly, both the power circuit and the control circuit of the developed battery charger are simplified. The switched capacitors circuit is applied to be the output of the boost converter and the input of the buck converter. The switched capacitors circuit can change its voltage according to the utility voltage so as to reduce the step-up voltage gain of the boost converter when the utility voltage is small. Hence, the power efficiency of a buck-boost type battery charger can be improved. Moreover, the step-down voltage gain of the buck power converter is reduced to increase the controllable range of the duty ratio for the common power electronic switch. A prototype is developed and tested to verify the performance of the proposed battery charger.

New Single-Phase Power Converter Topology for Frequency Changing of AC Voltage

Jou, Hurng-Liahng,Wu, Jinn-Chang,Wu, Kuen-Der,Huang, Ting-Feng,Wei, Szu-Hsiang The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3

This paper proposes a new single-phase power converter topology for changing the frequency of AC voltage. The proposed single-phase frequency converter (SFC) includes a T-type multi-level power converter (TMPC), a frequency decoupling transformer (FDT) and a digital signal processor (DSP). The TMPC can convert a 60 Hz AC voltage to a DC voltage and then convert the DC voltage to a 50 Hz AC voltage. Therefore, the output currents of the two T-type power switch arms have 50 Hz and 60 Hz components. The FDT is used to decouple the 50 Hz and 60 Hz components. The salient feature of the proposed SFC is that only one power electronic converter stage is used since the functions of the AC-DC and DC-AC power conversions are integrated into the TMPC. Therefore, the proposed SFC can simplify both the power circuit and the control circuit. In order to verify the functions of the proposed SFC, a hardware prototype is established. Experimental results verify that the performance of the proposed SFC is as expected.

New Single-Phase Power Converter Topology for Frequency Changing of AC Voltage

Hurng-Liahng Jou,Jinn-Chang Wu,Kuen-Der Wu,Ting-Feng Huang,Szu-Hsiang Wei 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3

This paper proposes a new single-phase power converter topology for changing the frequency of AC voltage. The proposed single-phase frequency converter (SFC) includes a T-type multi-level power converter (TMPC), a frequency decoupling transformer (FDT) and a digital signal processor (DSP). The TMPC can convert a 60 Hz AC voltage to a DC voltage and then convert the DC voltage to a 50 Hz AC voltage. Therefore, the output currents of the two T-type power switch arms have 50 Hz and 60 Hz components. The FDT is used to decouple the 50 Hz and 60 Hz components. The salient feature of the proposed SFC is that only one power electronic converter stage is used since the functions of the AC-DC and DC-AC power conversions are integrated into the TMPC. Therefore, the proposed SFC can simplify both the power circuit and the control circuit. In order to verify the functions of the proposed SFC, a hardware prototype is established. Experimental results verify that the performance of the proposed SFC is as expected.

Voltage Equalizing of Solar Modules for Shadowing Compensation

Jou, Hurng-Liahng,Wu, Kuen-Der,Wu, Jinn-Chang,Chung, Cheng-Huan,Huang, Ding-Feng The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

This paper proposes a shadowing compensation method for the solar modules of grid-connected photovoltaic generation systems. The shadowing compensator (SC) implemented by the proposed shadowing compensation method is used only for the solar modules that can be shaded by predictable sources of shading. The proposed SC can simplify both the power circuit and the control circuit as well as improve power efficiency and utilizes a voltage equalizer configured by a modified multi-winding fly-back converter. The proposed SC harvests energy from the entire solar cell array to compensate for the shaded sub-modules of the solar cell array, producing near-identical voltages of all shaded and un-shaded sub-modules in the solar cell array. This setup prevents the formation of multiple peaks in the P-V curve under shaded conditions. Hardware prototypes are developed for the SCs implemented by the conventional and modified multi-winding fly-back converters, and their performance is verified through testing. The experimental results show that both SCs can overcome the multiple peaks in the P-V curve. The proposed SC is superior to the SC implemented by the conventional multi-winding fly-back converter.

Voltage Equalizing of Solar Modules for Shadowing Compensation

Hurng-Liahng Jou,Kuen-Der Wu,Jinn-Chang Wu,Cheng-Huan Chung,Ding-Feng Huang 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

This paper proposes a shadowing compensation method for the solar modules of grid-connected photovoltaic generation systems. The shadowing compensator (SC) implemented by the proposed shadowing compensation method is used only for the solar modules that can be shaded by predictable sources of shading. The proposed SC can simplify both the power circuit and the control circuit as well as improve power efficiency and utilizes a voltage equalizer configured by a modified multi-winding fly-back converter. The proposed SC harvests energy from the entire solar cell array to compensate for the shaded sub-modules of the solar cell array, producing near-identical voltages of all shaded and un-shaded sub-modules in the solar cell array. This setup prevents the formation of multiple peaks in the P–V curve under shaded conditions. Hardware prototypes are developed for the SCs implemented by the conventional and modified multi-winding fly-back converters, and their performance is verified through testing. The experimental results show that both SCs can overcome the multiple peaks in the P–V curve. The proposed SC is superior to the SC implemented by the conventional multi-winding fly-back converter.

A Novel Transparent Microwave Thin Film Coating Technique Applied to Dual‑Band Antennas

Yu-Ming Lin,Hung-Wei Wu,Yung-Wei Chen,Cheng-Yuan Hung,Shoou-Jinn Chang,Yan-Kuin Su 대한금속·재료학회 2019 ELECTRONIC MATERIALS LETTERS Vol.15 No.6

In this paper, we propose a novel transparent microwave thin film coating technique and discuss its application in planardual-band antennas (0.9/5.55 GHz). We developed a new process for activating the nano-alignment thin film from high tolow resistivity (from 1.96 to 1.29 × 10−4 Ω cm) and from partial to full transparency (from 55 to 83% transmittance) within150 s. The platform of the activation process comprises a periodic electrode, an optical microscope, and an alternating currentsignal generator. The periodic electrode can effectively rearrange the nano-alignment thin film into an ordered arrangement,which enhances the properties of the thin film in the microwave frequency range. A high-transparency and low-resistivitydual-band antenna is designed and fabricated using the proposed microwave thin film coating technique. The dual-bandantenna has operating bandwidths of 740–960 and 5030–7030 MHz and potential applications in transparent electronicssuch as wearable devices and intelligent cars.