0195136047.pdf

754 BASIC CONTROL SYSTEMS Ac–ac converters (ac voltage controllers) Dc–dc converters (dc choppers) Dc–ac converters (inverters) ...

16.1 POWER SEMICONDUCTOR-CONTROLLED DRIVES 755 + TRIAC Ac supply Resistive load R G Vm Vm −Vm π π 2 π 2 π vs = Vm sin ωt ωt ωt v ...

756 BASIC CONTROL SYSTEMS + ++ + DC supply Load Vs VG 3 , VG 4 −Vs Vs Q 1 VG 1 VG 3 Q 4 Q 2 Q 3 G G t vo (a) (b) 0 − − −− 2 TT T ...

16.1 POWER SEMICONDUCTOR-CONTROLLED DRIVES 757 of the previous second-order homogeneous differential equation, we can solve for ...

758 BASIC CONTROL SYSTEMS vs = Vm sin ωt (a) vL vD i D R + − + + − − Figure 16.1.10Single-phase half-wave rectifier.(a)Circuit. ...

16.1 POWER SEMICONDUCTOR-CONTROLLED DRIVES 759 The rms value of a periodic waveform is given by Vrms= [ 1 T ∫T 0 v^2 L(t) dt ] 1 ...

760 BASIC CONTROL SYSTEMS PIV=Vm (16.1.17) Thedisplacement factorDF is given by cosφ, whereφis the angle between the fundamental ...

16.1 POWER SEMICONDUCTOR-CONTROLLED DRIVES 761 Vao Va (a) (b) (c) α Va Ia 0 + − Vao Imax Ia Va 90 ° 180 °^0 Fully controlled rec ...

762 BASIC CONTROL SYSTEMS Only thecontinuous conductionmode of operation of the drive for motoring and regenerative braking will ...

16.1 POWER SEMICONDUCTOR-CONTROLLED DRIVES 763 Fromαtoπ+αin the output voltage waveform of Figure 16.1.13(a), Equation (16.1.25) ...

764 BASIC CONTROL SYSTEMS Ia= ( 2 Vm/π )cosα−Kmωm Ra (16.1.38) Substituting in Equation (16.1.32), we get the following equation ...

16.1 POWER SEMICONDUCTOR-CONTROLLED DRIVES 765 Km= E ωm = 202. 66 188. 57 = 1. 075 For continuous conduction, Equation (16.1.38) ...

766 BASIC CONTROL SYSTEMS 60°, the firing of thyristors occurs in the same sequence as they are numbered. The line commutation o ...

16.1 POWER SEMICONDUCTOR-CONTROLLED DRIVES 767 (^0) π/3 ωt α T 4 T 6 va va ia ia T 5 T 1 T 5 T 2 T 3 T 4 E π 2 π AB AC BC BA CA ...

768 BASIC CONTROL SYSTEMS Solution (a) From Equation (16.1.42), withα=0, we get 220 = 3 √ 2 V π or V=163 V line-to-line; Vm= 230 ...

16.1 POWER SEMICONDUCTOR-CONTROLLED DRIVES 769 T 1 T (^4) T 1 T 4 A iA T 3 T 3 T 6 T 6 B N B A C T 5 T 2 T (^2) T 5 Stator windi ...

770 BASIC CONTROL SYSTEMS CS Figure 16.1.18Symbol of a self-commutated semiconductor switch. A common symbol for theself-commuta ...

16.1 POWER SEMICONDUCTOR-CONTROLLED DRIVES 771 (b) (^0) π 2 π 3 π ωt iC 1 (^0) ωt iC 2 (^0) ωt iC 3 (^0) ωt iC 4 (^0) ωt iC 5 (^ ...

772 BASIC CONTROL SYSTEMS For a wye-connected stator, the waveform of the phase current is shown in Figure 16.1.19, which is als ...

16.1 POWER SEMICONDUCTOR-CONTROLLED DRIVES 773 T= 3 ωS      Vrated^2 (R′ 2 /aS) ( R 1 a + R′ 2 aS ) 2 +(Xl 1 +X′l 2 )^2   ...