The capacitive-coupling grid-connected inverter (CGCI) is coupled to the point of common coupling via a second-order LC branch. Its operational voltage is much lower than that of a conventional ...inductive-coupling grid-connected inverter (IGCI) when it serves as a multifunctional inverter to compensate reactive power and transfer active power simultaneously. It is a promising solution for microgrid and building-integrated distributed generator systems. A quasi-proportional-resonant (quasi-PR) controller is applied to reduce the steady-state current tracking errors of the CGCI in this paper. The quasi-PR controller generates the voltage reference for use of carrier-based pulse-width modulation, which can effectively reduce output current ripples. The second-order coupling impedance of the CGCI causes its modeling and controller design to differ from that of the conventional IGCI. A comprehensive design method for the quasi-PR controller in a CGCI is developed. The quasi-PR controller is also compared with a proportional-integration current controller. Simulation results are provided to verify the effectiveness of the quasi-PR controller and its design method in a CGCI. The current tracking errors are greatly reduced when the quasi-PR controller rather than the proportional-integration controller is applied. Experimental results are also provided to validate the CGCI as a multifunctional grid-connected inverter.
This paper proposes a hybrid static synchronous compensator (hybrid-STATCOM) in a three-phase power transmission system that has a wide compensation range and low dc-link voltage. Because of these ...prominent characteristics, the system costs can be greatly reduced. In this paper, the circuit configuration of hybrid-STATCOM is introduced first. Its V-I characteristic is then analyzed, discussed, and compared with traditional STATCOM and capacitive-coupled STATCOM (C-STATCOM). The system parameter design is then proposed on the basis of consideration of the reactive power compensation range and avoidance of the potential resonance problem. After that, a control strategy for hybrid-STATCOM is proposed to allow operation under different voltage and current conditions, such as unbalanced current, voltage dip, and voltage fault. Finally, simulation and experimental results are provided to verify the wide compensation range and low dc-link voltage characteristics and the good dynamic performance of the proposed hybrid-STATCOM.
This paper proposes a control strategy for a three-phase three-wire thyristor-controlled LC -coupling hybrid active power filter (TCLC-HAPF), which can balance active power and compensate reactive ...power and harmonic currents under unbalanced loading. Compared with TCLC-HAPF with conventional control strategy, active power filters and hybrid active power filters which either fail to perform satisfactory compensation or require high-rating active inverter part for unbalanced compensation, a control strategy was proposed for TCLC-HAPF to operate with a small rating active inverter part for a variety of loads with satisfactory performance. The control idea is to provide different firing angles for each phase of the thyristor-controlled LC-coupling part (TCLC) to balance active power and compensate reactive power, while the active inverter part aims to compensate harmonic currents. First, the required different TCLC impedances are deduced. Then, independent firing angles referenced to the phase angle of voltage across TCLC are calculated. After angle transformations, final firing angles referenced to phase angle of load voltages are obtained. In this paper, a novel controller for TCLC-HAPF under unbalanced loading is proposed. Simulation and experimental results are provided to verify the effectiveness of the proposed controller in comparison with a state-of-the-art controller.
Small cell lung cancer (SCLC) accounts for approximately 13% of all lung cancer cases. Small cell lung cancer is characterized by frequent relapse, and current treatments lack tumor specificity. ...Arginine is a non‐essential amino acid for human normal cells but critical to some tumor cells that cannot synthesize arginine. Therefore, arginine deprivation has become a potential therapeutic option for selected tumors. BCT‐100 is a pegylated arginase that has documented anticancer activity in arginine auxotrophic tumors, such as melanoma, hepatocellular carcinoma, and acute myeloid leukemia. One of the resistance mechanisms to arginase treatment is overexpression of argininosuccinate synthetase (ASS1) and ornithine transcarbamylase (OTC), two important enzymes in the urea cycle. We selected 9 SCLC and 1 non‐small cell lung carcinoma cell lines to determine the growth inhibition effects of BCT‐100 and established that cell lines with low expression of ASS1 and OTC are relatively sensitive to BCT‐100 treatment. Knocking down OTC in a H841 cell line could potentiate its sensitivity to BCT‐100 treatment. Arginine concentration was sharply decreased, accompanied by apoptosis through oxidative stress as well as G1 cell cycle arrest. In addition, BCT‐100 showed an anticancer effect on H446 and H510A xenograft models by lowering arginine levels and inducing apoptosis.
BCT‐100 is one type of pegylated recombinant human arginase. BCT‐100 showed an anticancer effect against small cell lung cancer through oxidative stress, apoptosis, and cell cycle arrest.
In this paper, the structure, modeling, parameter design, and control method are proposed for a new hybrid structure of a static var compensator in parallel with a hybrid active power filter ...(SVC//HAPF). The SVC part of the SVC//HAPF is used to dynamically compensate the reactive power. And, the HAPF part is used to provide harmonic power and small amount of reactive power compensation. Due to the large fundamental voltage drop on coupling the LC part, the active inverter part of the SVC//HAPF has low voltage rating. Meanwhile, the parallel-connected SVC acts as a current divider to reduce the active inverter current. Therefore, the proposed SVC//HAPF shows the great promise in compensating harmonic current and wide-range reactive power with a low (both) voltage and current rating active inverter part. To show the advantages of the proposed SVC//HAPF, simulation comparisons among the active power filter (APF), HAPF, SVC in series with HAPF (SVC−HAPF), and the proposed SVC//HAPF are provided. Finally, experimental results based on the laboratory-scaled hardware prototype are given to show the validity of the SVC//HAPF.
In this paper, the structure, coordinate control method, and parameter design of a hybrid system are proposed for active power injection and nonactive power (reactive, harmonic, and unbalance power) ...compensation. The proposed hybrid system consists of a static var compensator (SVC) in parallel with a capacitive-coupling grid-connected inverter (CGCI) (SVC//CGCI). In SVC//CGCI, the SVC part is used to dynamic compensate the reactive power and unbalance power, while the low rating CGCI part is used to inject active power, provide harmonic power and a fixed amount of capacitive reactive power. Compared with conventional inductive-coupling grid-connected inverter (IGCI), the CGCI can provide active, reactive and harmonic power with low rating of active inverter part. The cost of the SVC part is much lower than that of active inverter part, thus the reduction of inverter rating can lead to a decrease in the total cost of the SVC//CGCI. Therefore, the SVC//CGCI can be a cost effective solution for active power injection and nonactive power compensation. Finally, simulation and experimental results are provided to show the advantages and validity of the proposed SVC//CGCI in compared with the conventional IGCI and SVC//IGCI.
In this paper, an adaptive dc-link voltage controlled thyristor-controlled LC-coupling hybrid active power filter (TCLC-HAPF) is proposed for reducing switching loss, switching noise, and enhancing ...the compensating performance. Unfortunately, the TCLC-HAPF has both controllable active TCLC part and active inverter part; thus, the conventional minimum dc-link voltage calculation methods for active power filter (APF) and LC-coupling hybrid APF (LC-HAPF) cannot be directly applied to the TCLC-HAPF. Moreover, the aforementioned dc-link voltage calculation methods were developed based on the fast Fourier transform (FFT), which makes the calculation complex. This paper also presents a simplified minimum dc-link voltage calculation method for TCLC-HAPF reactive power and current harmonics compensation, which can significantly reduce the large amount of the calculation steps by using the FFT method. After that, an adaptive dc-link voltage controller for the TCLC-HAPF is developed to dynamically keep its operating at its minimum dc-link voltage level to reduce its switching loss and switching noise. Finally, representative simulation and experimental results are given to verify the proposed simplified dc-link voltage calculation method and the adaptive dc-link voltage control method of TCLC-HAPF.
This paper proposes a new type dc/ac inverter named: hybrid-coupling grid-connected inverter (HGCI) for photovoltaic active power generation with power quality conditioning, which consists of a ...full-bridge three-phase dc/ac inverter coupling to the power grid in series with a thyristor-controlled LC filter. Compared with the conventional inductive-coupling grid-connected inverter (IGCI) and capacitive-coupling grid-connected inverter (CGCI), the proposed HGCI has distinct characteristics of wide operational range and low dc-link operating voltage. Based on these prominent characteristics, the system cost and operational cost can be reduced. Moreover, it can transfer the active power and compensate reactive power, unbalanced power, and harmonic power simultaneously. In this paper, the analysis of the structure, parameter design, and control method of the HGCI is proposed and presented. Finally, simulation and experimental results are provided to verify the effectiveness and performance of the proposed HGCI in comparison with the IGCI and CGCI.
When the load generated harmonic, unbalanced, and reactive power is beyond the limited capacity of a thyristor-controlled LC -coupling hybrid active power filter (TCLC-HAPF), the TCLC-HAPF with the ...conventional control methods cannot provide satisfactory compensation performance. In this paper, a selective compensation control method of harmonic distortion, unbalanced and reactive power of the TCLC-HAPF is proposed, which can function even at different voltage conditions (e.g., voltage dip, voltage fault, etc.). First, the proposed control method decomposes the load power into fundamental positive-sequence reactive power, fundamental negative-sequence power (unbalanced power), and harmonic power. Then, the decomposed reactive, unbalanced, and harmonic power can be selectively or fully compensated based on the capacity of the TCLC-HAPF. Finally, simulation and experimental results are provided to verify the effectiveness of the proposed selective compensation control method for the TCLC-HAPF.
In this study, a minimizing inverter capacity design is proposed, and the characteristics and performance of static VAR compensator (SVC) coupling hybrid active power filters (SVC-HAPFs) are ...analyzed. The cost of the SVC part is much lower than that of the active inverter part, and thus, the reduction of inverter part capacity can lead to a decrease in the total cost of SVC-HAPF. To demonstrate the advantages of the proposed minimizing inverter capacity design of SVC-HAPF, comparisons are given between the conventional and the proposed SVC-HAPF designs. Comparisons are also provided among active power filters (APFs), HAPFs, and the proposed SVC-HAPF in terms of dc-link voltage, compensation range, and performance. Finally, simulation and laboratory-scale experimental results are given to validate the minimizing inverter capacity design, and to verify the characteristics and compensation performances of APF, HAPF, and the proposed SVC-HAPF.
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