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wallscheid committed Jan 28, 2025
2 parents 24a1763 + 991dee6 commit 9b21412
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Original file line number Diff line number Diff line change
Expand Up @@ -11,13 +11,13 @@
enlargelimits,
axis line style={->}, % Pfeilspitzen an den Achsen
xlabel={$\omega t$},
ylabel={$U_\mathrm{1}$},
ylabel={$u_\mathrm{2a0}(\omega t)/ \SI{}{\volt}$},
xmin=0, xmax=13/6*pi,
ymin=-1, ymax=1,
xtick={0, pi/3, 2*pi/3, pi, 4*pi/3, 5*pi/3, 2*pi},
xticklabels={0, $\frac{1\pi}{3}$, $\frac{2\pi}{3}$,$\pi$, $\frac{4\pi}{3}$, $\frac{5\pi}{3}$, $2\pi$},
ytick={-2/3, -1/3, 0, 1/3, 2/3},
yticklabels={$-\frac{2}{3}$, $-\frac{1}{3}$, $0$, $\frac{1}{3}$, $\frac{2}{3}$},
yticklabels={$-340$, $-170$, $0$, $170$, $340$},
% grid=both,
% major grid style={line width=.2pt,draw=gray!50},
% minor grid style={line width=.1pt,draw=gray!20},
Expand All @@ -31,6 +31,6 @@
};
\end{axis}
\end{tikzpicture}
\caption{Section of the voltage curve $U_\mathrm{UM}$.}
\label{fig:voltage_uum_section}
\caption{Section of the voltage curve $u_\mathrm{2a0}(\mathrm{\omega t})$.}
\label{fig:voltage_u2a0_section}
\end{solutionfigure}
79 changes: 44 additions & 35 deletions exercise/fig/ex07/Fig_graphic_solutions_cos_terms.tex
Original file line number Diff line number Diff line change
Expand Up @@ -8,32 +8,39 @@
\centering
\begin{tikzpicture}
\begin{axis}[
% x/y range adjustment
xmin=-20, xmax=420,
ymin=-160, ymax=180,
width=7cm, height=7cm,
axis lines=middle,
xlabel={$\cos(\varphi)$},
ylabel={$\sin(\varphi)$},
xlabel style={xshift=0.5cm},
width=7cm, height=7cm,
major grid style={line width=.2pt,draw=gray!50},
minor grid style={line width=.1pt,draw=gray!20},
xmin=-1.5, xmax=1.5,
ymin=-1.5, ymax=1.5,
xtick={-1, 0, 1}, % Manuelle Ticks auf der x-Achse
ytick={-1, 0, 1}, % Manuelle Ticks auf der y-Achse
tick label style={xshift=5pt, yshift=5pt}, % Verschiebt die Beschriftungen nach außen
]

% Vektor einzeichnen
\draw[thick, ->] (0,0) -- ({cos(40)}, {sin(40)}) node[above right] {};
\node at ({0.5*cos(40)}, {0.5*sin(40)}) [below] {$\varphi$};

% Kreis zeichnen
\addplot[
domain=0:360,
samples=200,
thick,
color=blue,
]
({cos(x)}, {sin(x)});
% Label adjustment
x label style={at={(axis description cs:1,0.5)},anchor=west},
% x-Ticks
xtick={-1,0,1},
xticklabels={-1,,1},
xticklabel style = {anchor=north,shift={(0.25cm,0.1cm)}},
% y-Ticks
ytick={-1,0,1},
yticklabels={-1,,1},
yticklabel style = {anchor=east,shift={(0.1cm,0.2cm)}},
]

\draw[thick, ->] (0,0) -- ({cos(40)}, {sin(40)}) node[above right] {};
\node at ({0.5*cos(40)}, {0.5*sin(40)}) [below] {$\varphi$};

\addplot[
domain=0:360,
samples=200,
thick,
color=blue,
]
({cos(x)}, {sin(x)});
\end{axis}
\end{tikzpicture}
\end{minipage}
Expand All @@ -44,10 +51,10 @@
\draw[->] (-2,0) -- (2,0) node[right] {};
\draw[->] (0,-2) -- (0,2) node[above] {};
\node at (-1.5,1.5) {$\cos\left(k \frac{\pi}{2}\right)$};
\node at (-2,0) [left] {$2,6,\ldots$};
\node at (2,0) [right] {$0,4,\ldots$};
\node at (0,2) [above] {$1,5,9,13,\ldots$};
\node at (0,-2) [below] {$3,7,11,15,\ldots$};
\node at (-2,0) [left] {$k=2,6,\ldots$};
\node at (2,0) [right] {$k=0,4,\ldots$};
\node at (0,2) [above] {$k=1,5,9,13,\ldots$};
\node at (0,-2) [below] {$k=3,7,11,15,\ldots$};

% Kreuz bei jedem markierten Punkt
\foreach \x/\y in {-1.5/0, 1.5/0, 0/1.5, 0/-1.5} {
Expand All @@ -61,13 +68,13 @@
\begin{tikzpicture}
\draw[->] (-2,0) -- (2,0) node[right] {};
\draw[->] (0,-2) -- (0,2) node[above] {};
\node at (-2.5,1.5) {$\cos\left(k \frac{\pi}{3}\right)$};
\node at (-1,0.2) [left] {$3,9,15,21\ldots$};
\node at (1,0.2) [right] {$0,6\ldots$};
\node at (2,1) [above] {$1,7,13,19\ldots$};
\node at (-0.8,1.6) [below] {$2,8\ldots$};
\node at (-0.8,-1) [below] {$4,10\ldots$};
\node at (2,-1) [below] {$5,11,17,23\ldots$};
\node at (-2.7,1.8) {$\cos\left(k \frac{\pi}{3}\right)$};
\node at (-0.3,0.4) [left] {$k=3,9,15,21\ldots$};
\node at (1,0.4) [right] {$k=0,6\ldots$};
\node at (2,1) [above] {$k=1,7,13,19\ldots$};
\node at (-1.2,1.6) [below] {$k=2,8\ldots$};
\node at (-1.2,-1.1) [below] {$k=4,10\ldots$};
\node at (2,-1.1) [below] {$k=5,11,17,23\ldots$};
\node at (-0.75,-0.3) [left] {-1};
\node at (1,-0.3) [left] {0.5};
% Kreuz bei jedem markierten Punkt
Expand All @@ -93,7 +100,9 @@
% Koordinatensystem zeichnen
\draw[->] (-2,0) -- (2,0) node[right] {};
\draw[->] (0,-2) -- (0,2) node[above] {};
\node at (-1.5,1.5) {$\cos\left(k \frac{\pi}{3}\right)+1$};
% \node at (-1.5,1.5) {$\cos\left(k \frac{\pi}{3}\right)+1$};
\node at (-1.7,1.8) {$\cos\left(k \frac{\pi}{3}\right)+1$};


% Beschriftungen an der x-Achse
\node at (-0.00009,-0.2) [left] {0};
Expand All @@ -102,8 +111,8 @@
}

% Beschriftungen an spezifischen Punkten
\node at (1.5,1.1) [above] {$1,7,13,19,\ldots$};
\node at (1.5,-1.1) [below] {$5,11,17,23,\ldots$};
\node at (2,1.1) [above] {$k=1,7,13,19,\ldots$};
\node at (2,-1.1) [below] {$k=5,11,17,23,\ldots$};

% Kreuz bei jedem markierten Punkt
\foreach \x/\y in {0/0, 1.5/1, 1.5/-1} {
Expand All @@ -116,6 +125,6 @@
\draw[thick, color=blue!70!black]
(0,0) -- (1.5,1) -- (1.5,-1) -- cycle;
\end{tikzpicture}
\caption{Graphical solution of the cos terms.}
\label{fig:Graphical solution of the cos terms}
\caption{Graphical solution of the cos terms within complex plane.}
\label{fig:GraphicalSolutionOfInComplexPlane}
\end{solutionfigure}
Original file line number Diff line number Diff line change
Expand Up @@ -3,7 +3,7 @@
\begin{tikzpicture}
% Achsen zeichnen
\draw[->] (0,0) -- (14,0) node[right] {$k$}; % x-Achse
\draw[->] (0,0) -- (0,5) node[above] {$\frac{\hat{u}_\mathrm{2ae,k}}{\hat{u}_\mathrm{2ae,1}}$}; % y-Achse
\draw[->] (0,0) -- (0,5) node[above] {$\frac{\hat{u}_\mathrm{2a}^\mathrm{(k)}}{\hat{u}_\mathrm{2a}^\mathrm{(1)}}$}; % y-Achse

% Ticks und Beschriftungen auf der x-Achse
\foreach \x in {1, 5, 7, 11, 13} {
Expand Down
118 changes: 103 additions & 15 deletions exercise/tex/exercise07.tex
Original file line number Diff line number Diff line change
Expand Up @@ -228,11 +228,10 @@
\end{equation}
\end{solutionblock}

\subtask{Decompose the voltage $u_\mathrm{a}(t)$ into a Fourier series and sketch the spectral lines related to the
amplitude of the fu
ndamental signal up to order n=13. Hint: The following applies to the Fourier coefficients of an odd and alternating function:
\subtask{Decompose the voltage $u_\mathrm{2a}(t)$ into a Fourier series and sketch the spectral lines related to the
amplitude of the fundamental signal up to order n=13. Hint: The following applies to the Fourier coefficients of an odd and alternating function:
\begin{align*}
b_k = \frac{4}{\pi} \int_{0}^{\frac{\pi}{2}} f(x)\sin(kx) \mathrm{d}x \quad k =\mathrm{odd} \quad \quad
b_k = \frac{4}{\pi} \int_{0}^{\frac{\pi}{2}} f(x)\sin(kx) \mathrm{d}x \quad k =\mathrm{odd} \quad \quad
\end{align*}
\label{sub:DecomposeVoltage}
}
Expand All @@ -241,28 +240,117 @@
\begin{equation}
\begin{split}
a_\mathrm{k} &= 0 \\
a_\mathrm{k} &= \frac{4}{\pi} \int_0^{\pi/2} f(x)\sin(x) \mathrm{d}x \quad k=\mathrm{odd} \\
b_\mathrm{k} &= \frac{4}{\pi} \int_0^{\pi/2} f(x)\sin(x) \mathrm{d}x \quad k=\mathrm{odd} \\
f(x) &= \sum_{k}^{} \left( b_k \sin(kx) \right).
\end{split}
\end{split}
\end{equation}
The coefficients $b_k$ are the amplitudes of the respective harmonic. The voltage $u_{\mathrm{2a}}(t)$ needs
only to be integrated up to $\pi/2$. Only the terms with odd order numbers are taken into account.
Apply this to the current signal is expressed by
\begin{equation}
b_\mathrm{k} = \frac{4}{\pi} \int_0^{\pi/3} \frac{U_{\mathrm{1}}}{3} \sin(kt) \mathrm{d}t
+ \frac{4}{\pi} \int_{\pi/3}^{\pi/2} \frac{2U_{\mathrm{1}}}{3} \sin(kt) \mathrm{d}t
\end{equation}
Signal ratio $u_{\mathrm{2a0}}(\omega t)/U_{\mathrm{1}}$ is depicted in \autoref{fig:voltage_u2a0_section} for one periode.
\input{fig/ex07/Fig_Voltage_u2a0_excerpt}
\begin{equation}
\begin{split}
a_\mathrm{k} &= \frac{4}{\pi} \int_0^{\pi/3} f(x)\sin(x) \mathrm{d}x \quad k=\mathrm{odd} \\
f(x) &= \sum_{k}^{} \left( b_k \sin(kx) \right).
\end{split}
b_\mathrm{k} &= \frac{4U_{\mathrm{1}}}{3k\pi} \big[-\cos(kt)\mathrm{d}t \big]_0^{\pi/3}
+ \frac{4U_{\mathrm{1}}}{3k\pi} \big[-2\cos(kt)\mathrm{d}t \big]_{\pi/3}^{\pi/2} \\
&= \frac{4U_{\mathrm{1}}}{3k\pi} \left(-\cos(k\frac{\pi}{3})+\cos(0) -2 \cos(k\frac{\pi}{2})+ 2\cos(0) \right) \\
&= \frac{4U_{\mathrm{1}}}{3k\pi} \left( \cos(k\frac{\pi}{3})+ 1 -2 \cos(k\frac{\pi}{2})\right) \\
\text{with } &\cos(k\frac{\pi}{3})+1=1.5 \quad \text{for } k=n \cdot 6\pm1 \text{ is odd} \\
\text{and }&\cos(k\frac{\pi}{2})=0 \quad \text{ for } k=\text{ odd}
\end{split}
\end{equation}
The result is displayed in the complex plane in \autoref{fig:voltage_u2a0_section}.



\input{fig/ex07/Fig_Voltage_U_um_excerpt}
\input{fig/ex07/Fig_graphic_solutions_cos_terms}

\autoref{fig:voltage_u2a0_section} leads to
\begin{equation}
\hat{u}_\mathrm{2a0,k} = b_\mathrm{k} = \frac{4U_{\mathrm{1}}}{3k\pi} \cdot \frac{3}{2}=\frac{2U_{\mathrm{1}}}{k\pi}
\label{eq:Ex07T2_FundamentelVoltage}
\end{equation}
The amplitudes are depicted in \autoref{fig:NormalizationToTheAmplitude},
\input{fig/ex07/Fig_standardization_to_fudamental_freq.tex}
\input{fig/ex07/Fig_ trigonometric_approach_triangle.tex}
\end{solutionblock}
The relation between fundamental und harmonic amplitude is calculated by
\begin{equation}
\begin{split}
\frac{\hat{u}_\mathrm{2a0,1}}{\hat{u}_\mathrm{2a0,k}} &= \frac{1}{k} \\
\text{with } &k=n \cdot 6\pm1 \text{ and } n=1,2,3...
\end{split}
\end{equation}
\label{subtask:Ex07T2_FourierSeries}
\end{solutionblock}

\subtask{Based on \autoref{sub:DecomposeVoltage}, calculate the fundamental amplitude $\hat{i}_\mathrm{a}^1$ using a vector diagram and complex alternating current calculations.
\subtask{Based on \autoref{sub:DecomposeVoltage}, calculate the fundamental amplitude $\hat{i}_\mathrm{a}^1$ using a vector diagram and
complex alternating current calculations.
From this, determine the total active power converted in the load.}
\begin{solutionblock}
According \eqref{eq:Ex07T2_FundamentelVoltage} the fundamental voltage is calculated as:
\begin{equation}
\hat{u}_\mathrm{2a0,1}(t)=\frac{2U_{\mathrm{1}}}{1\pi}=\frac{2\cdot \SI{510}{\volt}}{1\pi}=\SI{324,68}{\volt}
\end{equation}
The amplitude of $u_\mathrm{2ae}(t)$ is given with
\begin{equation}
\hat{u}_\mathrm{2ae}=\sqrt{2} \cdot \SI{220}{\volt}=\SI{311,13}{\volt}
\end{equation}

A triangle is formed by the inverter voltage $u_\mathrm{2a}^\mathrm{(1)}(t)$, the voltage $u_\mathrm{2ae}(t)$
and the voltage drop across the inductance $L$. Two sides and one angle are known. By applying the sine theorem results in
\begin{equation}
\begin{split}
\frac{a}{\sin(\alpha)} = &\frac{b}{\sin(\beta)} = \frac{c}{\sin(\gamma)} \\
\text{with } a=\SI{324,68}{\volt} &\quad \alpha=\SI{120}{\degree} \quad b=\SI{311,13}{\volt}.
\label{eq:Ex07T2_SinTheorem}
\end{split}
\end{equation}
Solving \eqref{eq:Ex07T2_SinTheorem} with respect to $\beta$ leads to
\begin{equation}
\beta=\arcsin\big(\frac{b}{a}\sin(\alpha)\big)
=\arcsin\big(\frac{\SI{311,13}{\volt}}{\SI{324,68}{\volt}}\sin(\SI{120}{\degree})\big) = \arcsin(0,8298)=\SI{56.1}{\degree}.
\label{eq:Ex07T2_sin_beta}
\end{equation}
Using the result for $\beta$ leads to
\begin{equation}
\gamma=\SI{180}{\degree}-\alpha-\beta = \SI{180}{\degree}-\SI{120}{\degree}-\SI{56.1}{\degree}= \SI{3.9}{\degree}
\label{eq:Ex07T2_sin_beta}
\end{equation}
In \autoref{fig:IllustrationForUsingSineTheorem} the triangle is depicted.
\input{fig/ex07/Fig_ trigonometric_approach_triangle.tex}
In a symmetrical three-phase system, the active power is:
\begin{equation}
P=\sqrt{3} U_{\mathrm{L-L}} I_{\mathrm{L}} \cos(\phi)
\label{eq:Ex07T2_EffPowergen}
\end{equation}

$U_{\mathrm{L-L}}$ corresponds to the effective value of the line-to-line voltage and $IU_{\mathrm{L}}$ is the effective value
of the line current and $\phi$ is the phase angle between voltage and current. For this case $U_{\mathrm{L-L}}$ is calculated by
\begin{equation}
U_{\mathrm{L-L}}=\sqrt{3}\frac{\hat{u}_\mathrm{2a}^\mathrm{(1)}}{\sqrt{2}}
= \sqrt{\frac{3}{2}} \frac{2U_\mathrm{1}}{\pi} = \sqrt{3}\sqrt{2}\frac{U_\mathrm{1}}{\pi}
= \sqrt{3}\sqrt{2} \cdot \frac{\SI{510}{\volt}}{\pi}=\SI{397.6}{\volt}
\label{eq:Ex07T2_EffPowervoltage}
\end{equation}
The line current $I_{\mathrm{L}}$ is obtained by
\begin{equation}
I_{\mathrm{L}}=\frac{\hat{i}_\mathrm{2a}^\mathrm{(1)}}{\sqrt{2}}
= \frac{\SI{12.37}{\ampere}}{\sqrt{2}}=\SI{8.75}{\ampere}
\label{eq:Ex07T2_EffPowercurrent}
\end{equation}
The angle $\phi$ results in
\begin{equation}
\begin{split}
&\phi=\SI{30}{\degree}+ \gamma= \SI{30}{\degree}+\SI{3.9}{\degree}= \SI{33.9}{\degree}\phi=\SI{30}{\degree}+ \gamma= \SI{30}{\degree}+\SI{3.9}{\degree}= \SI{33.9}{\degree} \\
&\cos(\phi)=\cos(\SI{33.9}{\degree})=0.83
\end{split}
\label{eq:Ex07T2_EffPowerangle}
\end{equation}
Using \eqref{eq:Ex07T2_EffPowervoltage}, \eqref{eq:Ex07T2_EffPowercurrent} and \eqref{eq:Ex07T2_EffPowerangle}
in \eqref{eq:Ex07T2_EffPowergen} leads to
\begin{equation}
P=\sqrt{3} U_{\mathrm{L-L}} I_{\mathrm{L}} \cos(\phi)
= \sqrt{3} \SI{397.6}{\volt} \cdot \SI{8.75}{\ampere} \cdot 0.83= \SI{5}{\kilo\watt}
\end{equation}
\end{solutionblock}

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