價格：免費
更新日期：2019-07-25
檔案大小：2.7M
目前版本：1.20
版本需求：Android 4.1 以上版本
官方網站：mailto:colinharrison543@gmail.com
In electrical engineering, the method of symmetrical components simplifies analysis of unbalanced three-phase power systems under both normal and abnormal conditions. Using the mathematical method developed by Fortescue this app calculates the symmetrical components for 3 unbalanced phasors as well as the reverse. The app displays both graphical and digital results for the symmetrical components and unbalanced phasors.
User input can be either graphical or digital. For graphical input use the touch screen to drag the unbalanced phasors to the desired values. The same can be done with the symmetrical components (on touch down the app will select the closest red phase of the symmetrical components for input).
Digital input can be carried out by tapping on the digital display for either the unbalanced phasors or the symmetrical components. A dialog window will then open for input.
The keys at the bottom of the screen perform the following functions:
1) Settings (cog symbol): opens the settings menu and allows the user to select rectangular or polar coordinates, angular units (degrees or radians) as well as grid scale, font sizes and other settings.
2) Vector summation (plus sign): Displays the symmetrical components as a vector summation on the unbalanced phasor display.
3) Labels (tags symbol): Display identifying labels on all vectors on both unbalanced and symmetrical components displays.
4) Phases (exchange symbol): Cycle the symmetrical components digital display through all phases.
5) Reset (undo symbol): Return the phasors to a balanced state.
6) Exit app (power button symbol): Exit the app.
Miscellaneous
The symbol used in this app for the square root of minus 1 is "j". The digital input screen will accept complex numbers in rectangular, polar, exponential and trigonometric form. Solutions are converted to rectangular or polar form on the digital output display (depending on the settings).
The "a" key on the input keypad represents a cube root of one i.e. a=-0.5+j0.866
The "a" operator can be used to rotate a phasor by 120 degrees (similar to "j" rotating a phasor by 90 degrees).
The exponent key "^" on the digital input screen can be used to raise complex numbers the power of another complex number. Press the "^" to return the cursor to the base input level again. Square root, cube root etc can be calculated by using reciprocal for the exponent eg. 1/2, 1/3 etc. Tan can be calculated by using Sin(angle)/Cos(angle).
Radians/Degrees key - this key on the digital input screen designates the units for the angles entered. It will also detect and convert any angles on the digital input screen from radians to degrees or visa versa when pressed. This app uses the format of "Magnitude , Angle" for polar numbers. The app will detect the comma in the string and evaluate it as a polar number with the magnitude being to the left of the comma and the angle being to the right of the comma. Polar numbers can be entered while in Rectangular mode and the app will convert them to rectangular format.
For example the expression "e^(j*pi) , pi/4" will result in an answer of -0.707-j0.707 when in Rectangular mode or 1 , -2.356 (rad) when in Polar mode.i.e. The expression e^(j*pi) equates to -1 for the magnitude with an angle of 45 degrees to the right of the comma.
The app evaluates operators in the following order of precedence ^,trig,ln,/,*,-,+. Use brackets to ensure that the input expression is evaluated in the way that you expect.
For example:
-1^(1/2) will result in the answer -1 because the app will first calculate the square root of 1 and then apply the minus sign. To calculate the square root of minus one put the minus one in brackets as below.
(-1)^(1/2) will result in the answer "j" i.e. an imaginary number
Other examples where the use of brackets are required are:
-1-(-2)=1
ln(-2)=0.693+j3.142
sin(pi/4)
