No abstract

No abstract

An accurate dead-time adjustment method for phase-shifted full bridge (PSFB) converter is presented. This method allows the dead-time of converters to be optimised to meet zero voltage switching condition. The optimum dead-time range can be predicted with high accuracy for any type of power semiconductor switch, including gallium nitride high-electron-mobility transistor, so that a practical design for a PSFB converter can be realised. The validity of the proposed deadtime optimisation method was verified by experimental results with a 600 W prototype.

No abstract

No abstract

In this paper, a filter design guideline to reduce the ripple current in LLC resonant converters for the battery charger is proposed. The effect of filter inductor on the resonant network is mathematically analyzed, and a filter inductor is designed considering capacitance of the battery. The voltage gain of LLC resonant converter with filter inductor is analyzed through fundamental harmonic approximation (FHA) method. This research verifies performance of ripple current reduction compared with conventional LLC resonant converter without output filter inductor through mathematical analysis, simulation and experimental results.

Typical domestic induction cooktops can only heat ferromagnetic pots/vessels. However, to increase the availability and marketability of induction heating (IH) cooktop products, heating techniques for all types of metallic pots (i.e., created from metals such as aluminum, copper, and stainless steel) are required. To satisfy the requirements of induction cooktops, this paper proposes the design of an all-metal domestic IH system that can heat any type of metallic pot while considering the temperature variation of the working-coil. A control algorithm using a power curve-fitting method (CFM) is presented to quickly respond to load parameter variations in the IH. In addition, the CFM control algorithm is established to compensate for the power reference value by reflecting the increase in the working-coil temperature during the heating of the non-ferromagnetic pot. To evaluate the performance of the proposed system, the control algorithm strategy and experimental results based on a 3.2 kW all-metal IH cooktop are presented.Energies 2019, 12, 2915 2 of 16 follows. (1) A step-up/down converter topology for heating ferromagnetic and non-ferromagnetic pots by varying the DC-link voltage was proposed in References [6,7]. (2) An induction cooktop was developed in Reference [7] to heat low-resistivity pots using a double-layer working-coil structure with dual-resonant circuits. However, the studies presented in References [6][7][8] focused primarily on designing the hardware required to implement all-metal IH systems, and any experimental results based on the application of the pot material and the size-identification method as well as the control algorithm were not presented. (3) A half-bridge series resonant converter (HB-SRC) topology with two selective resonant capacitors and dual-resonant load circuits was proposed in References [9,10] to heat various pots with a resonant frequency changing scheme. In References [9,10], the research results on the identification of pot materials using electric power differences were presented; however, specific pot material and size-identification algorithms, control response, and actual identification experiments were not verified. (4) A HB-SRC operating in a third-harmonic operation mode was proposed in Reference [11] to heat various pots with a resonant frequency changing scheme. This proposed system demonstrated the advantages of minimizing the number of components in comparison with other all-metal IH topologies. However, there is a drawback that the equivalent input voltage was three times smaller than the conventional first-harmonic operation mode. Based on these studies, Panasonic Corp. developed an all-metal IH cooktop product by applying an international patent for a triplex series load resonant high-frequency technology operating at three times the switching frequency [9][10][11]. This cooktop utilized the power limit control method to prevent overvoltage/overcurrent based on minimum operating frequency and maximum voltage and current values. This conventional trip unit is...

No abstract