www.pudn.com > matlab±à³Ì.zip > calc_power.m

%  Script file: calc_power.m 
% 
%  Purpose:  
%    To calculate the current, real, reactive, and apparent power, 
%    and the power factor supplied to a load.  
% 
%  Record of revisions: 
%      Date       Programmer          Description of change 
%      ====       ==========          ===================== 
%    12/01/97    S. J. Chapman        Original code  
% 
% Define variables: 
%   amps      -- Current in the load 
%   p         -- Real power of load 
%   pf        -- Power factor of load 
%   q         -- Reactive power of the load 
%   s         -- Apparent power of the load 
%   theta     -- Impedance angle of the load 
%   volts     -- Rms voltage of the power source 
%   z         -- Magnitude of the impedance of the load 
 
% Degrees to radians conversion factor  
conv = pi / 180;         
 
% Prompt the user for the rms voltage. 
volts = input('Enter the rms voltage of the source: '); 
 
% Prompt the user for the magnitude and angle of the impedance. 
z = input('Enter the magnitude of the impedance in ohms: '); 
theta = input('Enter the angle of the impedance in degrees: '); 
 
% Perform calculations 
amps = volts / z;                       % Rms current 
p = volts * amps * cos (theta * conv);  % Real power 
q = volts * amps * sin (theta * conv);  % Reactive power 
s = volts * amps;                       % Apparent power 
pf = cos ( theta * conv);               % Power factor 
  
% Write out the results. 
fprintf('Voltage        =  %f volts\n',volts); 
fprintf('Impedance      =  %f ohms at %f degrees\n',z,theta); 
fprintf('Current        =  %f amps\n',amps); 
fprintf('Real Power     =  %f watts\n',p); 
fprintf('Real Power     =  %f watts\n',p); 
fprintf('Reactive Power =  %f VAR\n',q); 
fprintf('Apparent Power =  %f VA\n',s); 
fprintf('Power Factor   =  %f\n',pf);