本书依据教育部 2009 年颁发的《中等职业学校电工技术基础与技能教学大纲》、广东省教育厅 1999 年10 月颁发的《电动机控制电路教学大纲》、2025 年广东省中等职业技术教育专业技能"电工”课程考试要求为主要依据，同时参考有关职业资格标准、行业职业技能鉴定标准和企业岗位能力要求，并结合教学实践组织编写。 本书内容包括电工技术基础知识、电工技术基础技能、三相交流异步电动机控制电路，其中，电工技术基础知识的主要内容包括电路的基本概念和基本定律、直流电路分析、电容器、磁场和电磁感应、单相正弦交流电、三相交流电路、变压器；电工技术基础技能的主要内容包括常用电工工具及其使用，常用电工仪器、仪表的使用，电阻性电路故障的检查，正弦交流电路的测量，信号发生器与示波器，三相负载的星形连接，三相负载的三角形连接、安全用电常识，触电急救，电气火灾的预防与扑救；三相交流异步电动机控制电路的主要内容包括三相交流异步电动机基本知识、三相交流异步电动机控制电路的常用低压电器、三相交流异步电动机控制电路的连接。本书贴近企业岗位需要与学生实际，将理论与实践相结合，以加深学生对专业知识的理解，提高学生的学习兴趣和积极性。 本书可作为中等职业技术学校机电技术应用、电气设备运行与控制、电子技术应用、电子电器应用与维修、工业机器人技术应用、智能化生产线安装与运维等专业的基础教材，也可作为广东省春季高考专业技能课程考试的教材，还可作为中级电工的培训教材和工程技术人员的参考用书。

邓峻谔，现任学校智能制造部部长，高级讲师，电工高级技师、制冷高级技师。担任全国机械职业教育教学指导委员会能源装备专指委委员、广东省测量控制技术与装备应用促进会教学仪器装备专业委员会委员。

目 录
第 1 章 电工技术基础知识 ································································································1
1.1 电路的基本概念和基本定律 ························································································1
1.1.1 电路概述········································································································1
1.1.2 电流··············································································································3
1.1.3 电压与电位·····································································································5
1.1.4 电阻定律及电阻的标称值···················································································7
1.1.5 部分电路欧姆定律与伏安特性曲线·······································································9
1.1.6 电源的电动势及内阻······················································································.11
1.1.7 全电路欧姆定律与电源的外特性·······································································.11
1.1.8 电功率及能量转化·························································································.13
1.1.9 负载获得最大功率的条件················································································.16
1.2 直流电路分析 ·······································································································.17
1.2.1 串联电路和并联电路······················································································.17
1.2.2 电压源、电流源····························································································.22
1.2.3 基尔霍夫定律·······························································································.25
1.2.4 基尔霍夫定律在电路分析中的应用····································································.27
1.2.5 叠加原理和戴维南定理···················································································.28
1.2.6 电桥及其应用·······························································································.34
1.3 电容器 ················································································································.35
1.3.1 电容器的基本知识·························································································.35
1.3.2 电容器的连接·······························································································.38
1.4 磁场和电磁感应 ····································································································.40
1.4.1 磁场及其基本物理量······················································································.40
1.4.2 物质的磁化与磁导率······················································································.45
1.4.3 电磁感应·····································································································.47
1.4.4 线圈的电感及磁场能量···················································································.50
1.5 单相正弦交流电 ····································································································.52
1.5.1 交流电的基本概念·························································································.53
1.5.2 交流电的表示方法·························································································.56
1.5.3 纯电阻正弦交流电路······················································································.60
1.5.4 纯电感正弦交流电路······················································································.62
1.5.5 纯电容正弦交流电路······················································································.64
1.5.6 电阻与电感串联的正弦交流电路·······································································.67
1.5.7 电阻与电容串联的正弦交流电路·······································································.70
1.5.8 电阻、电感、电容串联的正弦交流电路······························································.74
1.5.9 电阻、电感、电容并联的正弦交流电路······························································.78
1.5.10 交流电路功率因数的提高 ··············································································.81
1.6 三相交流电路 ·······································································································.83
1.6.1 三相交流电的产生、表示方法及相序·································································.83
1.6.2 三相交流电源的连接······················································································.87
1.6.3 对称三相负载的连接······················································································.92
1.6.4 对称三相交流电路的功率················································································.97
1.7 变压器 ················································································································.99
第 2 章 电工技术基础技能 ·····························································································104
2.1 常用电工工具及其使用 ···························································································104
2.1.1 验电器········································································································104
2.1.2 电工钳········································································································105
2.1.3 扳手···········································································································107
2.1.4 电工刀具·····································································································109
2.2 常用电工仪器、仪表的使用 ·····················································································111
2.2.1 万用表的使用·······························································································111
2.2.2 电流表与电压表····························································································116
2.2.3 兆欧表········································································································119
2.2.4 电能表········································································································121
2.2.5 直流稳压电源·······························································································122
2.3 电阻性电路故障的检查 ···························································································123
2.3.1 电阻性电路的常见故障···················································································123
2.3.2 用万用表检查电阻性电路的常见故障·································································124 2
.4 正弦交流电路的测量 ······························································································126
2.4.1 正弦交流电路电压的测量················································································126
2.4.2 正弦交流电路电流的测量················································································128
2.5 信号发生器与示波器 ······························································································129
2.5.1 信号发生器及其使用······················································································129
2.5.2 示波器及其使用····························································································133
2.6 三相负载的星形连接 ······························································································142
2.6.1 对称和非对称三相负载的星形连接····································································142
2.6.2 负载为星形连接时电压、电流的测量·································································143
2.7 三相负载的三角形连接 ···························································································145
2.7.1 三相负载三角形连接的相序·············································································145
2.7.2 负载为三角形连接时电压、电流的测量······························································146
2.8 安全用电常识 ·······································································································146
2.8.1 安全电压·····································································································147
2.8.2 安全标志·····································································································147
2.8.3 安全措施·····································································································149
2.9 触电急救 ·············································································································152
2.9.1 预防触电的措施····························································································152
2.9.2 解救触电者··································································································155
2.9.3 紧急抢救·····································································································157
2.10 电气火灾的预防与扑救··························································································160
2.10.1 电气火灾的预防 ··························································································160
2.10.2 电气火灾的扑救 ··························································································161
第 3 章 三相交流异步电动机控制电路············································································164
3.1 三相交流异步电动机基本知识 ··················································································164
3.1.1 三相交流异步电动机的结构、工作原理和铭牌·····················································164
3.1.2 三相交流异步电动机定子绕组的连接·································································168
3.1.3 三相交流异步电动机的启动、调速与制动···························································170
3.2 三相交流异步电动机控制电路的常用低压电器 ·····························································175
3.2.1 熔断器········································································································176
3.2.2 低压开关·····································································································179
3.2.3 交流接触器··································································································183
3.2.4 继电器········································································································186
3.2.5 主令电器·····································································································194
3.3 三相交流异步电动机控制电路的连接 ·········································································199
3.3.1 三相交流异步电动机控制电路··········································································199
3.3.2 由时间继电器控制的星-三角降压启动控制电路的连接···········································208
3.3.3 三相交流异步电动机正/反转启动、能耗制动电路的连接········································216
3.3.4 两台三相交流异步电动机顺序启动控制电路的连接···············································222