本书主要介绍电路的基本概念、直流电路、正弦交流电路、三相正弦交流电路、非正弦周期电流电路和线性电路过渡过程的时域分析。本书注重理论联系实际, 突出基本概念和基本方法, 解析大量经典例题, 以便读者更好理解相关内容。 本书可作为高等职业院校电气、电子类专业或相近专业的“电路基础”课程的教材, 也可作为参加电工类各工种职业资格考试的备考用书, 还可作为对外培训用书。 This book mainly introduces the basic concepts of circuit, DC circuit, sinusoidal AC circuit, three-phase sinusoidal AC circuit, non-sinusoidal periodic current circuit, and time-domain analysis of transition process in linear circuit.This book focuses on theory with practice, highlighting the basic concepts and basic methods, and analyzes a large number of classic examples, so that the reader better understand the relevant contents. This book can be used as a textbook for the “Fundamentals of Circuit” courses in electrical and electronic majors in higher vocational colleges or similar majors, as well as a reference book for Vocational Qualification Examination in various types of electrical engineering. It can also be used as an external training book.
Chapter Ⅰ Basic concepts of circuit169
Section Ⅰ Circuit169
Ⅰ. Actual circuit169
Ⅱ. Circuit model170
Section Ⅱ Main physical quantities of circuit172
Ⅰ. Current172
Ⅱ. Voltage174
Ⅲ. Electric potential177
Ⅳ. Electromotive force179
Ⅴ. Power179
Ⅵ. Electric energy181
Ⅶ. Rated value181
Section Ⅲ Kirchhoff’s law 182
Ⅰ. Terminology182
Ⅱ. Kirchhoff’s current law183
Ⅲ. Kirchhoff’s voltage law 184
Section Ⅳ Circuit element186
Ⅰ. Resistance element186
Ⅱ. Inductance element190
Ⅲ. Capacitive element192
Ⅳ. Power supply element 195
Exercise Ⅰ200
Chapter Ⅱ DC circuit204
Section Ⅰ Resistors in series and in parallel204
Ⅰ. Equivalent transformation204
Ⅱ. Resistors in series205
Ⅲ. Resistors in parallel207
Ⅳ. Resistors in series-parallel 209
Section Ⅱ Star connection and delta connection of resistors213
Ⅰ. Star connection and delta connection213
Ⅱ. Equivalent transformation of star connection and delta connection213
Section Ⅲ Equivalence of power supply217
Ⅰ. Equivalent transformation of two circuit models of actual power supply217
Ⅱ. Series-parallel equivalence of voltage source219
Ⅲ. Series-parallel equivalence of current source221
Section Ⅳ Branch current method224
Ⅰ. Content of branch current method224
Ⅱ. General steps of branch current method225
Section Ⅴ Node voltage method227
Ⅰ. Content of node voltage method227
Ⅱ. Millman’s theorem230
Ⅲ. General steps of node voltage method230
Section Ⅵ Superposition theorem235
Section Ⅶ Thevenin’s theorem239
Ⅰ. Content of Thevenin’s theorem239
Ⅱ. Application of Thevenin’s theorem240
Exercise Ⅱ241
Chapter Ⅲ Sinusoidal AC circuit 247
Section Ⅰ Fundamentals of phasor247
Ⅰ. Vector247
Ⅱ. Complex number248
Section Ⅱ Basic concepts of sinusoidal quantity251
Ⅰ. Three elements of sinusoidal quantity251
Ⅱ. Phase difference of sinusoidal quantity253
Ⅲ. Effective value for periodic quantity and sinusoidal quantity254
Ⅲ. Phasor representation of sinusoidal quantity255
Section Ⅲ Load elements in sinusoidal AC circuit258
Ⅰ. Resistance element in sinusoidal AC circuit259
Ⅱ. Inductance element in sinusoidal AC circuit261
Ⅲ. Capacitive element in sinusoidal AC circuit264
Ⅳ. Impedance and admittance266
Section Ⅳ Fundamental laws of AC circuit275
Ⅰ. Ohm’s law in phasor form275
Ⅱ. Kirchhoff’s laws in phasor form275
Section V Power of sinusoidal AC circuit278
Ⅰ. Instantaneous power278
Ⅱ. Active power279
Ⅲ. Reactive power279
Ⅳ. Apparent power280
Ⅴ. Increase of power factor282
Section Ⅵ Phasor analysis method of sinusoidal AC circuit284
Section Ⅶ Resonance in circuit287
Ⅰ. Series resonance287
Ⅱ. Parallel resonance291
Exercise Ⅲ293
Chapter Ⅳ Three-phase sinusoidal AC circuit299
Section Ⅰ Connection of three-phase power299
Ⅰ. Symmetrical three-phase sinusoidal power299
Ⅱ. Connection of three-phase power301
Section Ⅱ Connection of three-phase load305
Ⅰ. Star connection of three-phase load305
Ⅱ. Delta connection of three-phase load306
Section Ⅲ Analysis of symmetrical three-phase circuit309
Ⅰ. Characteristics of symmetrical three-phase circuit310
Ⅱ. Calculation of symmetrical three-phase circuit311
Section Ⅳ Analysis of unsymmetrical three-phase circuit313
Ⅰ. Neutral point voltage method313
Ⅱ. Neutral point displacement314
Section Ⅴ Power of three-phase circuit319
Ⅰ. Active power, reactive power and apparent power319
Ⅱ. Instantaneous power of symmetrical three-phase circuit321
Ⅲ. Measurement of three-phase power323
Exercise Ⅳ326
Chapter Ⅴ Non-sinusoidal periodic current circuit330
Section Ⅰ Non-sinusoidal periodic signal330
Section Ⅱ Fourier series of periodic functions331
Section Ⅲ Effective value, average value and average power of non-sinusoidal periodic quantity334
Ⅰ. Effective value334
Ⅱ. Average value336
Ⅲ. Average power336
Ⅳ. Equivalent sinusoidal quantity338
Section Ⅳ Calculation of non-sinusoidal periodic current circuit340
Exercise Ⅴ345
Chapter Ⅵ Time-domain analysis of transition process in linear circuit348
Section Ⅰ Transformation theorem and calculation of initial value349
Ⅰ. Circuit transformation and transformation theorem349
Ⅱ. Calculation of initial value350
Section Ⅱ Zero-input response of first-order circuit353
Ⅰ. Zero-input response of RC circuit354
Ⅱ. Zero-input response of RL circuit358
Section Ⅲ Zero-state response of first-order circuit361
Ⅰ. Zero-state response of RC circuit362
Ⅱ. Zero-state response of RL circuit365
Section Ⅳ Complete response of first-order circuit368
Ⅰ. Resolution of complete response368
Ⅱ. Three-factor method for analyzing first-order circuit370
Exercise Ⅵ375
参考文献380