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This paper proposes a Unified Voltage and Pitch angle Control (UVPC) strategy for fixed speed wind farm. The focus put on guaranteeing the LVRT grid code requirement when the wind farm subjected to severe faults. The UVPC consist of static synchronous compensator (STATCOM) voltage control loops with adequate pitch angle control loops which are coordinated to enhance the low-voltage ride-through capability of the wind generators thereby, complying the low voltage ride through (LVRT) grid code requirement as desired by the Germany grid code. Different scenarios such as system without STATCOM and pitch-angle controller, with STATCOM only, and system with STATCOM and pitch-angle control (i.e. UVPC) are simulated. The simulation results show that the adoption of STATCOM and pitch angle controller fulfilling the LVRT grid code requirement to ensure the continuous operation of wind turbines. Furthermore, a concept of critical clearing time (CCT) is discussed and its utility has been emphasized. Calculations, simulations and measurements provide how the increased STATCOM rating can offer an enhanced stability margin. [ABSTRACT FROM AUTHOR]

Several researchers have focused on the environmental Kuznets curve (EKC) hypothesis to analyze environmental degradation using carbon dioxide (CO2) emissions and ecological footprint as dependent variables. However, analyzes based on these variables neglect the supply side of environmental sustainability. To address this shortcoming, this study aims to examine the determinants of the ecological footprint pressure index (EFPI) in the context of the EKC hypothesis. The EFPI provides a more detailed picture of environmental issues by considering both ecological footprint and biocapacity. Thus, the study aims to add scientific value to the existing literature by analyzing the EFPI under the EKC hypothesis for the first time. Building on this, our research investigates the effects of economic complexity (ECX), per capita income, and renewable energy consumption (REC) on the EFPI by adopting a novel econometric approach. The results of the Fourier autoregressive distributed lag (ARDL) method show a cointegration relationship between income, ECX, renewable energy and EFPI in Germany, Switzerland and Sweden. The long-term elasticities indicate that ECX reduces the EFPI in Germany and Switzerland, while renewable energy mitigates environmental pressure in Switzerland and Sweden. Our findings also confirm the validity of the EKC hypothesis for Germany and Sweden. Based on these findings, the study suggests that ECX, renewable energy and economic growth can all be used as policy instruments to reduce environmental pressure in the three member states of the European Union. [ABSTRACT FROM AUTHOR]