## 25 Reputation

4 years, 127 days

## MaplePrimes Activity

### These are questions asked by dareimert

Maple 2020

For some reason every := on my work sheet has turned to "d" how to if fix this.

## Solve a System of Equations With an Unkn...

Maple 2020

I am trying to plot generator reactive output (Q) over a range of generator power output (P) with field current (Ifldc) and terminal voltage (Et) constant using “solve”. The system of equations includes an interpolating fiction Ifld(el).

I’m looking for some help as to how to configure a solution. Attached are a few of my failed attempts.

The upload of my file deleats the "solve" fo my first try it is:

- Synchronous reactance of d-axis, Unsatuarted

- Synchronous reactance of q-axis, Unsatuarted

- leakage reactance d or q-axis

Open Ckt Sat Curve DS807-1a

First col=Ifld amps

Second col= el voltage behind leakage reactance

Plot OC saturation with field current in pu

iterpolate values of field current vs el from OC sat curve

Ifield as a function of el  ->

Solve for Q with

TRY1

Eq4:=

Eq7:=

TRY 2

 (1)

TRY3

## Atomic Variables ...

Maple

I'm trying to document some generator calculations that use terms line Xd'. In Maple that turns into a derivative. I converted several 'ed variables into atomic variables. They have made my work sheet unusable. They appear to randomly loose connecin to their assigned values and prevent numeric solutions by showing  up in symbolic form. Once this happens, I have to check each instance where the variable isuse to find where the loss/lossses occured. (copy and past each instance of the variable and check its value).

Once found I can't find a consistant way to re-associate them with the assigned value.

Any suggestions. See botton of attaced work sheet.

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/WS_Gen_I_and_E_for_fauls_on_HS_of_GSU_-_Time_Response_&_51V_Trip_Times_-R5a.mw .

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/WS_Gen_I_and_E_for_fauls_on_HS_of_GSU_-_Time_Response_&_51V_Trip_Times_-R5a.mw .

## Combining log10...

Maple

How do I combine log10 terms. I can do it with natural logs but I have not been able do do it with log10.

## Fourier Analysis of Piecewise Function ...

Maple

How do I extract harmonics and plot a spectrum from a piecewise function?

The function is "Ia" shown below near the bottom in the "Plot Line Current" section.

 (1)

Vmax =  RmsMS phase to neutral voltage

=

=

=

=

=

=

=

The  #1 diode is forward biased and switches on when Va>Vc (Va=Vc). The voltage VD will be equal to Va-Vb until diode #2 turns on when Vc< Vb. Then VD will equal Vc-Vc.

The switching angle for the diodes is given above. If phase control is used all commutation is delayed by the angle α.

Without phase delay the average (DC) voltage applied to the laod is the average value of the 6 commutation periods over one cycle:

Emax =  RmsMS phase to neutral voltage

 (2)

 (3)

Commutation

The switching between diodes can not occur instantaneously because the supply circuit is inductive. Current can not change instantaneously in and inductive circuit.
The transfer of load current from the out-going phase to the incomming phase is accomplshed by a period of symultaneous conduction of the two adjacent diodes the creation of a circulating current between these two phases that resembles short circuit between the two phases.

The circulating current produces equal voltage drop with opposid polarities in each phase. In the out-going phase the drop adds to the soruce voltage and in the incomming phase the drop subtracts from the source voltage. Only the drop in the incomming phase effects the DC output voltage.

During commutation intervil com1 to com2 phases a and c are shorted while Id is transfered from phase c to phase a. During this time voltage Va-Vb minus the voltage drop in a phase caused by the commutation. This voltage drop is 1/2 the Vac voltage.

 (4)

and      Va=Vc at π/6

 (5)

 (6)

 (7)

 (8)

 (9)

 (10)

DC output voltage

 (11)

 (12)

 (13)

Equating the intigral of the voltage drop between the phase A and C  to the intigral of the voltage rise across the two phase inductances (thes intigrals represent eqivalent flux).

 (14)

 (15)

 (16)

 (17)

 (18)

 (19)

 (20)

 (21)

Line Currents

 Commutation Intervals

Plot Line Currents

 Line Rms Current