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Ex07 Task2: Add missing correction and update solution.
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SevenOfNinePE committed Jan 29, 2025
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}
\end{tikzpicture}
\caption{Normalization to the amplitude of the fundamental oscillation.}
\label{fig:Normalization to the amplitude of the fundamental oscillation}
\label{fig:fig:NormalizationToTheAmplitude}
\end{solutionfigure}
30 changes: 17 additions & 13 deletions exercise/tex/exercise07.tex
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\toprule
Input voltages: & $U_\mathrm{1}=\SI{510}{\volt}$ \\
Internal voltages: & $u_{\mathrm{2ai}}(t) = \sqrt{2} \cdot \SI{220}{\volt} \cdot \sin(\omega_1t)$ \\
Angular load frequency: & $\omega_1 = \SI{2 \pi \cdot 30}{\frac{1}{\second}}$ \\
Angular load frequency: & $\omega_1 = \SI{2 \pi \cdot 30}{\frac{1}{\second}}$ \\ 11
Inductance per phase: & $L= \SI{10}{\milli \henry}$ \\
Phase angle between $u_{\mathrm{2ai}}(t)$ and $i_{\mathrm{2ai}}^\mathrm{(1)}(t)$ & $\alpha=\SI{30}{\degree}$ \\
Phase angle between $u_{\mathrm{2ai}}(t)$ and $i_{\mathrm{2ai}}^\mathrm{(1)}(t)$ & $\varphi_{\mathrm{2ai}}^\mathrm{(1)}=\SI{30}{\degree}$ \\
\bottomrule
\end{tabular}
\caption{Parameters of three-phase inverter in six-step mode.}
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\end{equation}
The amplitudes are depicted in \autoref{fig:NormalizationToTheAmplitude},
\input{fig/ex07/Fig_standardization_to_fudamental_freq.tex}
\FloatBarrier
The relation between fundamental und harmonic amplitude is calculated by
\begin{equation}
\begin{split}
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\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}
\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
The amplitude of $u_\mathrm{2ai}(t)$ is given with
\begin{equation}
\hat{u}_\mathrm{2ae}=\sqrt{2} \cdot \SI{220}{\volt}=\SI{311,13}{\volt}
\hat{u}_\mathrm{2ai}=\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 $u_\mathrm{2ae}(t)$
The angle between $u_\mathrm{2ai}(t)$ and the voltage drop at the inductor is calculated by
\begin{equation}
\alpha=\SI{90}{\degree}+\varphi_{\mathrm{2ai}}^\mathrm{(1)}=\SI{90}{\degree}+\SI{30}{\degree}=\SI{120}{\degree}.
\end{equation}
A triangle is formed by the inverter voltage $u_\mathrm{2a}^\mathrm{(1)}(t)$, the voltage $u_\mathrm{2ai}(t)$
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}
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\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)
P=\sqrt{3} U_{\mathrm{L-L}} I_{\mathrm{L}} \cos(\varphi)
\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
of the line current and $\varphi$ 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}
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= \frac{\SI{12.37}{\ampere}}{\sqrt{2}}=\SI{8.75}{\ampere}
\label{eq:Ex07T2_EffPowercurrent}
\end{equation}
The angle $\phi$ results in
The angle $\varphi$ 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
&\varphi=\SI{30}{\degree}+ \gamma= \SI{30}{\degree}+\SI{3.9}{\degree}= \SI{33.9}{\degree} \\
&\cos(\varphi)=\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)
P=\sqrt{3} U_{\mathrm{L-L}} I_{\mathrm{L}} \cos(\varphi)
= \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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