tiểu luận Giải tích máy điện nâng cao

BỘ CÔNG THƯƠNG TRƯỜNG ĐH CÔNG NGHIỆP THỰC PHẨM TP HCM BÀI TIỂU LUẬN: GIẢI TÍCH MÁY ĐIỆN NÂNG CAO GVHD: TS Phan Xuân Lễ Thực hiện: Lê Thành Trí TP Hồ Chí Minh, năm 2019 Câu 1: A three-phase, 460V, 60Hz, eight-pole induction machine is driven by a wind turbine The induction machine has the following parameters: R1  0.015 ; R�  0.035 L  0.385mH L �  0.385mH L m  17,24mH 2 ; ; ; The induction machine is connected to a 460V infinite bus through a feeder having a resistance of 0.01 and an inductance of 0.08 mH The wind turbine drives the induction machine at slip of -0.5% a) Determine the speed of the wind turbine: 60 f 60.60 n  (1  s)  (1  (0.005))  904.5(rpm) p b) Determine the voltage at the terminals of the induction machine: The equivalent circuit of the induction machine:    j 6.5   7  j 0.145   0.01  j 0.03  0.015  j 0.145 j 6.5   7  j 0.145  4.83а 130.7 (  ) 460 Vs I1    54.99� 130.7�(A) Z 4.83а 130.7 The voltage at the terminals of the induction machine: 460    54.99� 130.7��   0.01  j0.03  =268.57� 60.63�(V) Vt  Vs  I1Z line  c) Determine the power delivered to the infinite bus and the power factor: Power delivered to the infinite bus: Ps  �Vs �I1 cos   �Vs �I1 cos(  ( 130.7o )  �268.57 �54.99 � 0.652  =-28.89(KW) d) Determine the efficiency of the system: Pag  Ps  3I12  0.01  0.015   29.116 (KW) Pmech    s  Pag    0.005  �29.116  29.26 (KW) Assume the rotational and core losses to be 3KW � Prot  (KW) � Pshaft  Pmech  Prot  29.26   32.26 (KW)  Ps 28.89   0.89 Pshaft 32.26  The efficiency of the system is 89% Câu 2: Ứng dụng simulink matlab xây dựng mô theo Fugure 2.11 Xây dựng mơ hình Figure 2.11 Simulation of series resonant circuit File m4.m R = 12; %R in ohms L = 0.231e-3; %L in H C = 0.1082251e-6;%C in Farad wo = sqrt(1/(L*C)) % series resonant frequency in rad/sec Vdc = 100; % magnitude of ac voltage = Vdc Volts iLo = 0; % initial value of inductor current vCo = 0; % initial voltage of capacitor voltage tf = 10*(2*pi/wo); % filter time constant tstop = 25e-4; % stop time for simulation % set up time and output arrays of repeating sequence for Pref Pref_time = [ 6e-4 11e-4 11e-4 18e-4 18e-4 tstop ]; Pref_value = [ 600 600 300 300 600 600 ]; % determine steadystate characteristics of RLC circuit we = (0.5*wo: 0.01*wo: 1.5*wo);% set up freq range wind = % index for w loop for w = we; % w for loop to compute admittance wind = wind + 1; Y(wind) = 1/(R + j*w*L + 1/(j*w*C)); Irms = (4*Vdc/(pi*sqrt(2)))*abs(Y(wind)); % rms value of i PR(wind)= Irms*Irms*R; end; % for w % plot circuit characteristics clf; subplot(2,1,1) plot(we,abs(Y)); xlabel('frequency in rad/sec'); ylabel('admittance in mhos'); subplot(2,1,2) plot(we,PR); xlabel('frequency in rad/sec'); ylabel('power in watts'); disp('run simulation, type ''return'' when ready to continue') keyboard clf subplot(4,1,1) plot(y(:,1),y(:,2)) title('excitation voltage') ylabel('Vs in V') subplot(4,1,2) plot(y(:,1),y(:,3)) title('load power') ylabel('PR in W') subplot(4,1,3) plot(y(:,1),y(:,4)) title('RLC current') ylabel('i in A') subplot(4,1,4) plot(y(:,1),y(:,5)) xlabel('time in sec') title('capacitor voltage') ylabel('VC in V') Kết mô Figure 2.12 Admittance and power absorbed of series RLC circuit Figure 2.13 Responses to changes in the reference power command Kết mô từ Simulink: Trình tự thực nội dung mơ a) Trình tự thực - Xây dựng khối Khối có khai báo file m4.m run file m4.m - Kết nối khối theo figure 2.11 - Xây dựng file m4.m b) Nội dung mô phỏng: Figure 2.11 mô mạch cộng hưởng RLC mắc nối tiếp - Run file m4.m có figure 2.12: sơ đồ tổng dẫn lượng mạch RLC nối tiếp Tắt figure 2.12 - Run again file m4.m có figure 2.13: sơ đồ đáp ứng thay đổi công suất tham chiếu - Run file simulink có sơ đồ đáp ứng thay đổi cơng suất tham chiếu Câu 3: Ứng dụng simulink matlab xây dựng mô theo Fugure 6.39 Xây dựng mơ hình Figure 6.39 File m6.m % M file for Project on single-phase induction motor % in Chapter It sets the machine parameters and % also plots the simulated results when used in conjunction % with SIMULINK file s6.m clear all % clear workspace % select machine parameter file to enter into Matlab workspace disp('Enter filename of machine parameter file without m') disp('Example: psph') setX = input('Input machine parameter filename > ','s')% string s eval(setX); % evaluate MATLAB command % Calculation of torque speed curve Vqs = Vrated + j*0; % rms phasor voltage of main wdg Vpds = Nq2Nd*(Vrated + j*0);% rms aux wdg voltage referred to main wdg T = (1/sqrt(2))*[ -j; j ]; % transformation V12 = T*[Vqs; Vpds];% transforming qsds to sequence disp('Select with or without capacitor option') opt_cap = menu('Machine type? ','No capacitor','With start capacitor only','With start and run capacitor') if (opt_cap == 1) % Split-phase machine, no capacitor disp(' Split-phase machine') zpcstart = +j*eps; % zcrun referred to main wdg zpcrun = +j*eps; % zcrun referred to main wdg zC = zpcstart; Capstart = 0; % set flag Caprun = 0; % set flag wrswbywb = we; % cutoff speed to disconnect start cpacitor end % if if (opt_cap == 2) % Capacitor-start machine disp(' Capacitor-start machine') zpcstart = (Nq2Nd^2)*zcstart; % zcrun referred to main wdg zpcrun = +j*eps; % zcrun referred to main wdg zC = zpcstart; Capstart = 1; % set flag Caprun = 0; % set flag wrswbywb = 0.75; % rotor speed to disconnect start cpacitor end % if if (opt_cap == 3) % Capacitor-run machine disp(' Capacitor-run machine') zpcstart = (Nq2Nd^2)*zcstart; % zcrun referred to main wdg zpcrun = (Nq2Nd^2)*zcrun; % zcrun referred to main wdg zC = zpcrun; Capstart = 0; % set flag Caprun = 1; % set flag wrswbywb = 0.75; % rotor speed to changeover from start to run end % if Rcrun = real(zpcrun); % referred resistance of run capacitor Xcrun = imag(zpcrun); % referred reactance of run capacitor Crun = -1/(wb*Xcrun); % referred capacitance of run capacitor Rcstart = real(zpcstart); % referred resistance of start capacitor Xcstart = imag(zpcstart); % referred reactance of run capacitor Cstart = -1/(wb*Xcstart); % referred capacitance of start capacitor % network parameters of positive and negative sequence circuit zqs = rqs + j*xlqs; % self impedance of main wdg zcross = 0.5*(rpds + real(zC) - rqs) + j*0.5*(xplds + imag(zC) - xlqs); %set up vector of slip values s = (1:-0.02:0); N=length(s); for n=1:N s1 = s(n); % positive sequence slip s2 = 2-s(n); % negative sequence slip wr(n)=2*we*(1-s1)/P; % rotor speed in mechanical rad/sec if abs(s1) < eps; s1 = eps; end; zp1r = rpr/s1 + j*xplr; z1s= j*xmq*zp1r/(zp1r + j*xmq); if abs(s2)< eps; s2 = eps; end; zp2r = rpr/s2 + j*xplr; z2s= j*xmq*zp2r/(zp2r + j*xmq); z11 = zqs + z1s + zcross; z22 = zqs + z2s + zcross; zmat = [ z11 -zcross; -zcross z22 ]; I12 = inv(zmat)*V12; I1s = I12(1); I2s = I12(2); Iqd = inv(T)*[I1s; I2s]; Sin =[Vqs Vpds]*conj(Iqd); Pin = real(Sin); angIq(n) =angle(Iqd(1))*180/pi; angId(n) =angle(Iqd(2))*180/pi; magIq(n) =abs(Iqd(1)); magId(n) =abs(Iqd(2)); Ip1r = -j*xmq*I1s/(zp1r + j*xmq); Ip2r = -j*xmq*I2s/(zp2r + j*xmq); Tavg(n)=(P/(2*we))*(abs(Ip1r)^2*rpr/s1 abs(Ip2r)^2*rpr/s2); Pavg(n)=Tavg(n)*wr(n); if abs(Pin) < eps; Pin = eps; end; eff(n)=100*Pavg(n)/Pin; end % n for loop N=size(wr); subplot(3,2,1) plot(wr,Tavg,'-') xlabel('Rotor speed in rad/sec') ylabel('Torque in Nm') subplot(3,2,2) plot(wr,Pavg,'-') xlabel('Rotor speed in rad/sec') ylabel('Developed power in Watts') subplot(3,2,3) plot(wr,magIq,'-') xlabel('Rotor speed in rad/sec') ylabel('|Iqs| in A') subplot(3,2,4) plot(wr,magId,'-') xlabel('Rotor speed in rad/sec') ylabel('|Ipds| in A') subplot(3,2,5) plot(wr,eff,'-') xlabel('Rotor speed in rad/sec') ylabel('Efficiency in percent') subplot(3,2,6) plot(wr,angIq,'-') hold on plot(wr,angId,'-.') xlabel('Rotor speed in rad/sec') ylabel('Iqs and Ipds angle in degree') hold off disp('Displaying steady-state characteristics ') fprintf('Referred capacitor impedance is %.4g %.4gj Ohms\n', real(zC), imag(zC)) disp('type ''return'' to proceed on with simulation'); keyboard % Transfer to keyboard for simulation disp('Select loading during run up') opt_load = menu('Loading? ','No-load','With step changes in loading') % setting all initial conditions in SIMULINK simulation to zero Psiqso = 0; Psipdso = 0; Psipqro = 0; Psipdro = 0; wrbywbo = 0; % initial pu rotor speed % set up repeating sequence Tmech signal if (opt_load == 1) % No-load tstop = 2; % simulation run time tmech_time =[0 tstop]; tmech_value =[0 0]; end if (opt_load == 2) % Step changes in loading tstop = 2.5; % simulation run time tmech_time =[0 1.5 1.5 1.75 1.75 2.0 2.0 2.25 2.25 2.5]; tmech_value =[0 -Tb -Tb -Tb/2 -Tb/2 -Tb -Tb 0 ]; end disp('Set for simulation to start from standstill and ') disp('load cycling at fixed frequency,') disp('return for plots after simulation by typing '' return'''); keyboard % Convert referred values back to actual Vds = y(:,3)/Nq2Nd; Ids = y(:,8)*Nq2Nd; Vcap = y(:,4)/Nq2Nd; Psids = y(:,7)/Nq2Nd; disp('Plot results in two figure windows') h1=gcf; subplot(5,1,1) plot(y(:,1),y(:,2),'-') ylabel('Vqs in V') subplot(5,1,2) plot(y(:,1),Vds,'-') ylabel('Vds in V') subplot(5,1,3) plot(y(:,1),y(:,9),'-') axis([-inf inf -1 1]) ylabel('Tmech in Nm') subplot(5,1,4) plot(y(:,1),y(:,10),'-') ylabel('Tem in Nm') subplot(5,1,5) plot(y(:,1),y(:,11),'-') xlabel('Time in sec') ylabel('wr/wb in pu') h2=figure; subplot(5,1,1) plot(y(:,1),Vcap,'-') ylabel('Vcap in V') subplot(5,1,2) plot(y(:,1),y(:,5),'-') ylabel('Psiqs in V') subplot(5,1,3) plot(y(:,1),y(:,6),'-') ylabel('Iqs in A') subplot(5,1,4) plot(y(:,1),Psids,'-') ylabel('Psids in V') subplot(5,1,5) plot(y(:,1),Ids,'-') xlabel('Time in sec') ylabel('Ids in A') disp('Save plots in Figs 1, and 2') disp('before typing return to exit'); keyboard; close(h2); File psph.m % Parameters of single-phase induction motor for Project of Chapter Sb = 186.5; % 1/4 hp rating in VA Prated = 186.5; % 1/4 hp output power in W Vrated = 110; % rated rms voltage in V P = 4; % number of poles frated = 60; % rated frequency in Hz wb = 2*pi*frated;% base electrical frequency we = wb; wbm = 2*wb/P; % base mechanical frequency Tb = Sb/wbm; % base torque Zb = Vrated*Vrated/Sb; %base impedance in ohms Vm = Vrated*sqrt(2); % magnitude of phase voltage Vb = Vm; % base rms voltage Tfactor = P/(2*wb); % torque expression coefficient % 1/4 hp, pole, 110 volts capacitor start, capacitor run, % single-phase induction motor parameters in engineering units from % % Krause, P C , "Simulation of Unsymmetrical Induction % Machinery," IEEE Trans on Power Apparatus, % Vol.PAS-84, No.11, November 1965 % Copyright 1965 IEEE Nq2Nd = 1/1.18; % Nqs/Nds main to aux wdg turns ratio rqs = 2.02; % main wdg resistance xlqs = 2.79; % main leakage reactance rds = 7.14; % aux wdg resistance xlds = 3.22; % aux leakage reactance rpds=(Nq2Nd^2)*rds;% aux wdg resistance referred to main wdg xplds=(Nq2Nd^2)*xlds;% aux wdg leakage reactance referred to main wdg xplr = 2.12; % rotor leakage reactance referred to main wdg rpr = 4.12; % rotor wdg resistance referred to main wdg xmq = 66.8; % magnetizing reactance referred to main wdg xMq = 1/(1/xmq + 1/xlqs + 1/xplr); xMd = 1/(1/xmq + 1/xplds + 1/xplr); J = 1.46e-2; % rotor inertia in kg m2 H = J*wbm*wbm/(2*Sb); % rotor inertia constant in secs Domega = 0; % rotor damping coefficent zcstart = - j*14.5; % starting capacitor in Ohms zcrun = - j*172; % running capacitor in Ohms wrsw = 0.75*wb; % rotor speed to change over from start to run in rev/min Kết mô Figure 6.40 Steady-state characteristics of ¼-hp split-phase moto Figure 6.41 Startup and load response of ¼-hp split-phase moto Figure 6.42 Startup and load response of ¼-hp split-phase moto Figure 6.43 Steady-state characteristics of ¼-hp capacitor-start motor Figure 6.44 Startup and load response of ¼-hp capacitor-start motor Figure 6.45 Startup and load response of ¼-hp capacitor-start motor Figure 6.46 Steady-state characteristics of ¼-hp capacitor-run motor Figure 6.47 Startup and load response of ¼-hp capacitor- run motor Figure 6.48 Startup and load response of ¼-hp capacitor- run motor Trình tự thực nội dung mơ a) Trình tự thực - Xây dựng khối ExtConn, Qaxis, Daxis, Rotor Khối ExtConn Khối Qaxis Khối Daxis Khối Rotor b) Kết nối khối theo figure 6.39 Xây dựng file m6.m Xây dựng file psph.m Nội dung mơ Run ¼-hp split-phase moto - Run file m6.m, cửa sổ Command Window thông báo : Enter filename of machine parameter file without m Example: psph - - - - - Input machine parameter filename > Nhập psph, chọn No cacpacitor Machine type figure 4.60 Cửa sổ Command Window, nhập K>> return Run file s6.m, run file simulink, run again file m6.m figure 4.61 figure 4.62 Run ¼-hp capacitor-start motor Run file m6.m, cửa sổ Command Window thông báo : Enter filename of machine parameter file without m Example: psph Input machine parameter filename > Nhập psph, chọn With start cacpacitor only Machine type figure 4.63 Cửa sổ Command Window, nhập K>> return Run file s6.m, run file simulink, run again file m6.m figure 4.64 figure 4.65 Run ¼-hp capacitor- run motor Run file m6.m, cửa sổ Command Window thông báo : Enter filename of machine parameter file without m Example: psph Input machine parameter filename > Nhập psph, chọn With start and run cacpacitor Machine type figure 4.66 Cửa sổ Command Window, nhập K>> return Run file s6.m, run file simulink, run again file m6.m figure 4.67 figure 4.68