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The output voltage range of renewable energy generations such as wind and photovoltaic can be influenced by the parameters of environment at a wide range, which can not satisfy the requirements of system for grid-connected operation. Therefore high-gain voltage inverter is important to integrate the renewable energy into the utility. For high-gain voltage and standard load voltage at low input DC...
The difficulty of modeling a resonant converter is the fact that, unlike a pulse-width-modulation (PWM) converter, an average concept doesn't work. The only successful equivalent circuit model, proposed by E. Yang, is based on fundamental approximation and harmonic balance theory. However, it is conceptually hard to understand because of an unidentified “equilibrium state.” A resonant converter was...
This paper proposes two methods for optimal design of DC bus reference voltage (Vdcref) and an optimal selection of the shunt active filter (SAF) inductor. The proposed methods help to reduce the filter rating, devices stress and increase the performance of the SAF. An optimal choice of the inductor of the SAF is presented based on the slope calculation of the SAF current which was demonstrated to...
Fast detection and isolation of DC faults is recognized as the main challenge in developing DC transmission grids. Voltage source converter blocking must be prevented which can be very difficult given the large rate-of-rise of fault currents. The concept of multi-converter DC bus is introduced as a grid design approach aimed towards increasing robustness of DC grids to DC faults. Behavior of a multi-converter...
A novel current mirror sensing based multi-phase current balance developed in Global Foundry 0.18μm CMOS process was presented in this paper. Different from conventional current mirror sensing method, a new bypass branch was added to make the sample signal more accurate in high switching frequency situation. The method was realized in a 2.5MHz four-phase buck converter. As the simulation result shows,...
A novel PWM/PFM hybrid-mode auto-change technique for buck DC-DC converter is proposed. The proposed technique utilizes the comparator propagation delay to decide the mode changing point without adding complicated PMW/PFM hybrid-mode controller. The proposed concept enables compact and simple implementation of hybrid-mode buck DC-DC converter. Simulation results show that the buck DC-DC converter...
This paper proposed a new soft-switched non-isolated bidirectional converter for energy storage systems. The hard-switched non-isolated bidirectional converter is improved with additional soft-switch cell incorporated with auxiliary active switches, diodes and passive elements. The main operating characteristics of this topology are to transfer the power flow in both directions from low voltage to...
This paper proposes an application of adaptive dual current mode control (ADCMC) on bidirectional bridgeless power factor correction (BBPFC) boost rectifier with unipolar switching. The given simulation results confirm the benefits of the proposed control strategy of the BBPFC converter, primarily regarding the maintaining of the sine waveform of the average inductor current.
In this paper, a high gain boost converter based on the voltage-lift technique is proposed. The converter is composed of basic quasi-Z-source cell and a voltage-lift cell which contains one capacitor, two inductors and diodes. Contrasted with the traditional quasi-Z-source DC/DC converter, a relatively high voltage conversion and the reduction of the input current ripple can be achieved with the presented...
Traditional Z-source inverter can boost or buck voltage for its unique impedance network, but also has its own drawbacks, such as input current is not continuous, boost capacity is limited, the capacitor voltage stress is large and etc. In order to overcome the shortcomings of the traditional Z-source inverter, a series of Z-source inverters are proposed. In this paper, the topology of three kinds...
In this paper, a concept is presented for simplifying and accelerating the development and testing process of a Permanent Magnet Synchronous Machine (PMSM), or its control unit, without utilizing any actual electric machine. The proposed Permanent Magnet Synchronous Machine Emulator (PMSME) utilizes the Power-Hardware-In-the-Loop (PHIL) concept to reproduce the mechanical and electrical characteristics...
Recently introduced Bi-directional Z-Source breakers [1] are capable of clearing the short circuit fault within a few microseconds. In this paper, various applications and protection requirements for Bidirectional Z-Source breakers are discussed. Detailed comparison between de-rated AC breakers and Z-Source breakers is discussed. Breaker design criteria are explained with the help of simulation results...
A control algorithm for an integrated power factor correction (PFC) and series resonant converter (SRC) using only two switches is presented, allowing to open loop control the AC input current and the DC output current independently. The theory for this approach is analyzed in time domain and a novel approach for open loop regulation is presented and verified. The software defined power (SDF) control...
In order to achieve high-quality, high-dynamic power amplification a method is proposed to split and process the current ripple independently from the main bulk current. As a consequence, low-power switching circuits with reduced stress, so-called basic crossover correction cells, can be effectively applied. Comparisons are presented to validate the proposals.
There are problems with insulation failures in high-voltage transformers due to fast transient voltages. Within novel Solid-State Transformers (SST) this problem exists constitutionally because of the SSTs rectangular working voltages. Experiments and simulations have been performed to get accurate understanding of the phenomena. The results and theories are discussed in this paper.
Verifying attacks against cyber physical systems can be a costly and time-consuming process. By using a simulated environment, attacks can be verified quickly and accurately. By combining the simulation of a cyber physical system with a hybrid attack graph, the effects of a series of exploits can be accurately analysed. Furthermore, the use of a simulated environment to verify attacks may uncover...
Recent years, multilevel inverters have become more attractive for researchers due to low total harmonic distortion (THD) in the output voltage and low electromagnetic interference (EMI). This paper proposes a three-phase cascaded H-bridge quasi-switched-boost inverter (CHB-qSBI). The advantages of the proposed inverter are as follows: buck-boost voltage with single stage power conversion, reduced...
In this paper, a fluid-thermal coupled finite element model is established to calculate the temperature field of dry type air core reactor, the inner structure of reactor is built both considering the calculation accuracy and computation time. According to simulation results, the detailed temperature distribution regularity are given both with and without the rain cover, and it can be achieved that...
In this paper, an electronically tunable immitance circuit is proposed. The presented circuit can be configured as a tunable grounded inductor or capacitor multiplier. The proposed circuit employs a single active element called Voltage Differential Current Conveyor, a single resistor and a single capacitor. The presented circuit does not require element matching constraints. It is linearly tunable...
Single-stage buck-boost gird-connected inverter is widely used in distributed generation systems because of low cost and high efficiency. However, shoot-through problem exists, so reliability of the system is reduced. In addition, output voltage of renewable energy resources varies widely with load and environmental condition, so voltage stress of switches is high in wide input-voltage range application...
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