计及负荷同时系数的谐波电流限值确定方法

确定非线性负荷的谐波电流限值是谐波评估进而谐波治理的基础工作,这样如何设计适当的计算方法就至关重要。基于谐波国家标准GB/T 14549-93和IEC国际标准IEC 61000-3-6,首先给出了描述公共连接点(Point of Common Coupling,PCC)的供电设备容量与用户用电协议容量之间关系的方程式。之后,借鉴在IEC标准中所采用的考虑负荷同时系数的方法,提出了在谐波国标中考虑负荷同时系数的思路和谐波电流限值计算新方法。通过GB/T 14549-93和IEC 61000-3-6这两个标准的相互佐证,并以某电力系统的实测数据为例,说明了所提方法的合理性。

Method for calculating harmonic current limits considering a load coincidence factor

Determining harmonic current limits for nonlinear loads is the fundamental of harmonic evaluation and mitigation,hence it is very important to design an appropriate approach.Based on the national standard GB/T 14549-93 and IEC standard 61000-3-6,the relationship between the power supply equipment capacity at the point of common coupling(PCC) and the customer electricity capacity agreed is first formulated.Then,the coincidence factor in the IEC standard is carefully examined.The concept of employing the coincidence factor in the national standard is proposed and a new method of determining the harmonic current limits is presented.The proposed method is demonstrated by both of the national standard GB/T 14549-93 and IEC standard 61000-3-6,as well as measuring data of harmonic currents in an actual power system.