2025年高比例新能源大电网短路电流计算报告.pdf

Core Viewpoint - China's renewable energy installed capacity continues to lead globally, with significant implications for the power grid and short-circuit current calculations, necessitating innovative technical support for the safe and stable operation of new power systems [1]. Group 1: Background of Technological Change - Traditional power systems relied on synchronous generators for short-circuit current calculations, which are now challenged by the integration of renewable energy sources through power electronic converters, leading to significant discrepancies in short-circuit current characteristics [2]. - The error rate of traditional calculation methods can reach 31.1%, while new classification modeling methods reduce this error to 14.4% [2]. Group 2: Paradigm Shift in Calculation Systems - A comprehensive technical innovation system has been established, including: - Upgraded foundational theories with revised standards addressing high-voltage systems and new modeling methods for asynchronous motors [3]. - Breakthroughs in renewable energy modeling, with dynamic models for wind, solar, and storage devices achieving testing errors below 10% [4]. - A simulation verification system that shows an 18.4% reduction in deviation from traditional methods in a 26-node grid test, enhancing equipment selection safety [5]. Group 3: Response to Electrified Power Grids - The widespread integration of power electronic devices has transformed the generation mechanism of short-circuit currents, with classification modeling methods providing significant advancements: - Grid-connected devices adjust models dynamically based on control strategies, such as the behavior of doubly-fed wind turbines [6]. - Networked devices utilize virtual impedance and current-limiting characteristics for accurate short-circuit current predictions [7]. - A highly efficient calculation method based on matrix exponential functions for flexible DC systems, improving calculation speed by 416 times compared to traditional simulations [8]. Group 4: China's Leadership in International Standards - China has transitioned from a follower to a leader in the formulation of international short-circuit current standards: - All 10 core standards from IEC TC73 have been converted into domestic standards, laying the groundwork for technical alignment [9]. - The proposed "controlled current source" model has driven upgrades in IEC standards, filling global gaps in high-voltage direct current short-circuit current standards [10]. - China has taken the lead in establishing international standards in areas such as smart low-voltage switchgear, marking a significant breakthrough in power equipment standards [11]. Group 5: Benchmark Case of Practical Application - The Zhejiang power grid's implementation of 500 kV flexible short-circuit current suppression technology demonstrates significant results, achieving a 30% reduction in short-circuit current within 10 milliseconds after a fault, addressing both excess short-circuit current and insufficient local short-circuit capacity [12]. - This report represents a culmination of technological innovation and a significant contribution to global energy governance, marking a leap from theoretical breakthroughs to standard leadership in the field of renewable energy short-circuit current calculations [12].