低压网络电动机启动时母线电压的计算

赵金剑（悉地国际设计顾问(深圳)有限公司，广东省深圳市 518057）

Calculation of Busbar Voltage at the Startup of Low‑voltage Network Motor

ZHAO Jinjian（CCDI Group(Shenzhen)Co.，Ltd.，Shenzhen 518057，Guangdong Province，China）

Abstract：Some problems in the calculation formula and examples of busbar voltage when the motor starts in the Industrial and Civil Power Supply and Distribution Design Manual are analyzed. As per characteristics of low‑voltage network，based on the equivalent voltage source method in Short‑circuit Current Calculation in Three‑phase a.c. Systems — Part 1：Calculation of Currents(GB / T 15544.1 - 2013 / IEC 60909 - 0：2001)，the impedance partial voltage principle is adopted to calculate the bus voltage when the low‑voltage network motor starts，a new calculation method is proposed and specific calculation examples are given. The data analysis is performed on the influence of bus voltage at different connected loads.

Key words：low‑voltage network;startup of motor;relative value of busbar voltage;system of named units;complex impedance;resistance;reactance;preconnected load

摘　要：分析《工业与民用供配电设计手册》中电动机启动时母线电压计算公式和算例中的一些问题。结合低压网络的特点，基于GB / T 15544.1 - 2013 / IEC 60909 - 0:2001《三相交流系统短路电流计算 第1部分：电流计算》的等效电压源方法，采用阻抗分压原理，对低压网络电动机启动时母线电压的计算，提出新的计算方法，给出具体计算示例。并在有无预接负载的不同情况下，对母线电压的影响加以数据分析。

关键词：低压网络；电动机启动；母线电压相对值；有名单位制；复数阻抗；电阻；电抗；预接负载

中图分类号：TU852    　　　　   文献标识码：A

doi：10.3969 / j. issn.1003 － 8493.2021.06.010