From 1d4f50f9aae6236fe7b8f5345f39065911b34ba9 Mon Sep 17 00:00:00 2001 From: SevenOfNinePE Date: Mon, 25 Nov 2024 12:26:57 +0100 Subject: [PATCH 1/2] Ex04 Correct task2+3 according review result Ex04_OW --- ...Tab_ForwardConverterWithAsymHalfBridge.tex | 6 +- ...Fig_ForwardConverterWithAsymHalfBridge.tex | 4 +- .../ex04/Fig_SingledEndedForwardConverter.tex | 62 ++++++++++--------- exercise/tex/exercise04.tex | 37 +++++------ 4 files changed, 56 insertions(+), 53 deletions(-) diff --git a/exercise/fig/ex04/FigTab_ForwardConverterWithAsymHalfBridge.tex b/exercise/fig/ex04/FigTab_ForwardConverterWithAsymHalfBridge.tex index 8c85ef8..7e3b58a 100644 --- a/exercise/fig/ex04/FigTab_ForwardConverterWithAsymHalfBridge.tex +++ b/exercise/fig/ex04/FigTab_ForwardConverterWithAsymHalfBridge.tex @@ -2,15 +2,15 @@ % Parameter of the forward converter with asymmetric half-bridge %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\begin{table}[ht] +\begin{table}[htb] \centering % Zentriert die Tabelle \begin{tabular}{llll} \toprule Input voltage: & $U_{\mathrm{1}} = \SI{325}{\volt}$ & Output voltage: & $U_{\mathrm{2}} = \SI{15}{\volt}$ \\ Output power: & $P_{\mathrm{2}} = \SI{50}{\watt}$ & Switching frequency: & $f_{\mathrm{s}} = \SI{50}{\kilo\hertz}$ \\ - Winding ration: & $N_{\mathrm{1}}/N_{\mathrm{2}}=10$ & Inductance: & $L_{\mathrm{1}}=\SI{2}{\milli\henry}$ \\ + Turns ration: & $N_{\mathrm{1}}/N_{\mathrm{2}}=10$ & Magnetizing inductance: & $L_{\mathrm{m}}=\SI{2}{\milli\henry}$ \\ \bottomrule \end{tabular} - \caption{Parameter of the circuit.} + \caption{Parameter overview of the circuit.} \label{table:Ex04_Forward converter with asymmetric half-bridge} \end{table} \ No newline at end of file diff --git a/exercise/fig/ex04/Fig_ForwardConverterWithAsymHalfBridge.tex b/exercise/fig/ex04/Fig_ForwardConverterWithAsymHalfBridge.tex index 7297336..42a27ba 100644 --- a/exercise/fig/ex04/Fig_ForwardConverterWithAsymHalfBridge.tex +++ b/exercise/fig/ex04/Fig_ForwardConverterWithAsymHalfBridge.tex @@ -64,7 +64,7 @@ (jLtpv) ++(-0.5,0) node[currarrow](IP){} (IP) node[anchor=south,color=black]{$i_\mathrm{p}$} % Add transformer primary inductor with voltage arrow - (jLtpv) to [L,l_=$N_\mathrm{1}$, n=Ltp, v_=$U_\text{p}$, voltage shift=5, voltage=straight] (jLtpg) + (jLtpv) to [L,l_=$N_\mathrm{1}$, n=Ltp, v_=$u_\text{p}$, voltage shift=5, voltage=straight] (jLtpg) % Add connections point for secondary inductor (jLtpv) ++(0.8,0) coordinate (jLtsv); % Add iron core @@ -78,7 +78,7 @@ % Add transformer secondary inductor with voltage arrow (jLtsv) ++(0,-2) coordinate (jLtsg) % Add transformer secondary inductor with voltage arrow - (jLtsv) to [L,l^=$N_\mathrm{2}$,n=Lts,mirror,v^=$U_\text{s}$, voltage shift=5, voltage=straight] (jLtsg); + (jLtsv) to [L,l^=$N_\mathrm{2}$,n=Lts,mirror,v^=$u_\text{s}$, voltage shift=5, voltage=straight] (jLtsg); \path (Ltp.ul dot) node[circ]{}; \path (Lts.ul dot) node[circ]{}; \draw diff --git a/exercise/fig/ex04/Fig_SingledEndedForwardConverter.tex b/exercise/fig/ex04/Fig_SingledEndedForwardConverter.tex index 0f1554b..7a8ea9e 100644 --- a/exercise/fig/ex04/Fig_SingledEndedForwardConverter.tex +++ b/exercise/fig/ex04/Fig_SingledEndedForwardConverter.tex @@ -10,26 +10,26 @@ % Base point for voltage supply (0,0) coordinate (jU1v) % Add supply U1 - (jU1v) to [V=$U_1$] ++(0,-4) coordinate (jU1g) + (jU1v) to [V=$U_\mathrm{1}$] ++(0,-4) coordinate (jU1g) % Add junction for inductor LT (jU1v) to [short,-*] ++(2,0) coordinate (jLTv) - % Add junction for diode DFP - (jLTv) ++ (0,-2) coordinate (jDFPk) + % Add junction for diode D3 + (jLTv) ++ (0,-2) coordinate (jD3k) % Add inductor LTv - (jDFPk) to [L,l=$L_\mathrm{T}$,n=L1,v_<=$U_\text{T}$, voltage shift=0.5, voltage=straight] (jLTv) + (jD3k) to [L,l=$L_\mathrm{3}$,n=L1,v_<=$U_\mathrm{3}$, voltage shift=0.5, voltage=straight] (jLTv) % Add winding text - (jDFPk) node[right] {$N_\mathrm{T}$}; + (jD3k) node[right] {$N_\mathrm{3}$}; \path (L1.ul dot) node[circ]{}; \draw % Add arrow and Text - (jDFPk) ++(0,-0.5) node[currarrow,rotate=90](IT){} + (jD3k) ++(0,-0.5) node[currarrow,rotate=90](IT){} (IT) node[anchor=east,color=black]{$i_\mathrm{T}$} - % Add connection point of the diode DFP - (jDFPk) ++(0,-2) coordinate (jDFPa) - % Add diode DFP - (jDFPa) to [D,l^=$D_\mathrm{Fp}$] (jDFPk) + % Add connection point of the diode D3 + (jD3k) ++(0,-2) coordinate (jD3a) + % Add diode D3 + (jD3a) to [D,l^=$D_\mathrm{3}$] (jD3k) % Add connection to U1g - (jDFPa) to [short,-] (jU1g) + (jD3a) to [short,-] (jU1g) % Add junction for transformer Ltpv (jLTv) to [short,-] ++(2.5,0) coordinate (jLtpv) % Add arrow and Text @@ -47,12 +47,14 @@ (jTs) to [short,-] (Trans1.S) (jTd) to [short,-] (Trans1.D) (Trans1.G) to [sqV] ++(1,0) - % Add connection to diode DFp - (jTs) to [short,-*] (jDFPa) + % Add connection to diode D3 + (jTs) to [short,-*] (jD3a) % Assign Transistor drain junction to primary junction point (jTd) coordinate (jLtpg) % Add transformer primary inductor with voltage arrow - (jLtpv) to [L,l_=$N_\mathrm{1}$, n=Ltp, v_=$U_\text{p}$,voltage shift=5, voltage=straight] ++(0,-2) coordinate (jLtpg) + (jLtpv) to [L,l_=$L_\mathrm{1}$, n=Ltp, v_=$U_\mathrm{p}$,voltage shift=5, voltage=straight] ++(0,-2) coordinate (jLtpg) + % Add turn name of primary inductor + (jLtpg) node[left] {$N_\mathrm{1}$} % Add junctions for secondary inductor (jLtpv) ++(0.8,0) coordinate (jLtsv) (jLtpg) ++(0.8,0) coordinate (jLtsg); @@ -65,7 +67,7 @@ (\x1/2+\x2/2, \y1) -- (\x1/2+\x2/2, \y2); \draw % Add transformer secondary inductor with voltage arrow - (jLtsv) to [L,l^=$N_\mathrm{2}$,n=Lts,mirror,v^=$U_\text{s}$, voltage shift=5, voltage=straight] (jLtsg); + (jLtsv) to [L,l^=$N_\mathrm{2}$,n=Lts,mirror,v^=$U_\mathrm{s}$, voltage shift=5, voltage=straight] (jLtsg); \path (Ltp.ul dot) node[circ]{}; \path (Lts.ul dot) node[circ]{}; \draw @@ -73,27 +75,27 @@ (jLtsv) ++(0.5,0) node[currarrow](IS){} (IS) node[anchor=south,color=black]{$i_\mathrm{s}$} % Add D1 - (jLtsv) to [D,l^=$D_1$] ++ (3,0) coordinate (jD1k) - % Add junction point for DFsk - (jD1k) to [short,-*] ++(0,0) coordinate (jDFsk) - % Add junction point for DFsa - (jDFsk) ++ (0,-2) coordinate (jDFsa) - % Add diode DFs - (jDFsa) to [D,l^=$D_\mathrm{Fs}$] (jDFsk) - % Add inductor L - (jDFsk) to [L,l=$L$,n=L1] ++(3,0) coordinate (jU2v) + (jLtsv) to [D,l^=$D_\mathrm{1}$] ++ (3,0) coordinate (jD1k) + % Add junction point for D2k + (jD1k) to [short,-*] ++(0,0) coordinate (jD2k) + % Add junction point for D2a + (jD2k) ++ (0,-2) coordinate (jD2a) + % Add diode D2 + (jD2a) to [D,l^=$D_\mathrm{2}$] (jD2k) + % Add inductor L4 + (jD2k) to [L,l=$L_\mathrm{4}$,n=L1] ++(3,0) coordinate (jU2v) % Add arrow and Text - (jDFsk) ++(0.5,0) node[currarrow](IL){} + (jD2k) ++(0.5,0) node[currarrow](IL){} (IL) node[anchor=south,color=black]{$i_\mathrm{L}$} % Add output voltage U2 - (jU2v) to [V=$U_2$] ++(0,-2) coordinate (jU2g) - % Add connection to DFs - (jU2g) to [short,-*] (jDFsa) + (jU2v) to [V=$U_\mathrm{2}$] ++(0,-2) coordinate (jU2g) + % Add connection to D2 + (jU2g) to [short,-*] (jD2a) % Add connection to secondary transformer LTsg - (jDFsa) to [short,-] (jLtsg); + (jD2a) to [short,-] (jLtsg); \end{circuitikz} \end{center} - \caption{Single Ended Forward Converter circuit.} + \caption{Single ended forward converter circuit.} \label{fig:ex04_SingledEndedForwardConverter} \end{figure} diff --git a/exercise/tex/exercise04.tex b/exercise/tex/exercise04.tex index 906fe3a..be9520f 100644 --- a/exercise/tex/exercise04.tex +++ b/exercise/tex/exercise04.tex @@ -115,26 +115,27 @@ \task{Forward converter with asymmetric half-bridge} -The schematic of a forward converter with asymmetric half-bridge is shown in \autoref{fig:ex04_ForwardConverterWithAsymHalfBridge}. +The schematic of a forward converter with an asymmetric half-bridge is shown in \autoref{fig:ex04_ForwardConverterWithAsymHalfBridge}. For the calculations the diodes and transistors are considered as ideal components. \input{./fig/ex04/Fig_ForwardConverterWithAsymHalfBridge} -The parameters are listed in \autoref{fig:ex04_ForwardConverterWithAsymHalfBridge} -\input{./fig/ex04/FigTab_ForwardConverterWithAsymHalfBridge} +The parameters are listed in \autoref{fig:ex04_ForwardConverterWithAsymHalfBridge}. +\input{./fig/ex04/FigTab_ForwardConverterWithAsymHalfBridge} +\FloatBarrier The leakage inductance, the resistive losses, and the core losses of the transformer are negligible. The converter operates in steady-state conditions. Both transistors are controlled by the same signal. \subtask{At what duty cycle $D$ does the circuit operate?} -\subtask{Calculate the average value of $i_\mathrm{2}$ and $i_\mathrm{1}$ over a clock cycle, +\subtask{Calculate the average value of $\overline{i_\mathrm{2}}$ and $\overline{i_\mathrm{1}}$ over a switching cycle, assuming ideal filtering of $i_\mathrm{2}$.} \subtask{Calculate the peak value of $\hat{i}_\mathrm{m}$ the magnetizing current $i_\mathrm{m}$.} -\subtask{Sketch the waveforms of $U_\mathrm{p}$, $i_\mathrm{m}$, $i_\mathrm{p}$ and $i_\mathrm{1}$ - for the case of non-ideal current smoothing $L \neq \infty$.} +\subtask{Sketch the waveforms of $u_\mathrm{p}$, $i_\mathrm{m}$, $i_\mathrm{p}$ and $i_\mathrm{1}$ + considering switching-induced ripples.} \subtask{Calculate the minimal necessary input voltage $U_\mathrm{1}$, if the output voltage $U_\mathrm{2}$ = \SI{20}{\volt} shall being constant.} -\subtask{Calculate the inductance of $L$, if the peak-to-peak value $\Delta i_\mathrm{pp}$ of the - switching frequency ripple current $\Delta i_\mathrm{2}$ is to be 10\% of the average value $I_\mathrm{2}$?} +\subtask{Calculate the inductance of $L$,such that the ripple current $\Delta i_\mathrm{2}$ is to be $\SI{10}{\percent}$ of the + average output current $\overline{I_\mathrm{2}}$?} @@ -151,23 +152,23 @@ The parameters are listed in \autoref{table:Ex04_Parameters of the singled ended forward converter.}. The output inductance is dimensioned so that the current $i_\mathrm{L}$ exhibits a continuous waveform. The transformer's leakage inductance can be neglected. + \input{./fig/ex04/FigTab_SingledEndedForwardConverter} -\subtask{Calculate the turns ratio $N_\mathrm{T}$/$N_\mathrm{1}$ so that the maximum blocking voltage +\subtask{Calculate the turns ratio $N_\mathrm{3}$/$N_\mathrm{1}$ so that the maximum blocking voltage across the transistor during demagnetization is $\SI{600}{\volt}$.} \subtask{What is the maximum permissible duty cycle of the power transistor in this case?} \subtask{What turns ratio $N_\mathrm{1}$/$N_\mathrm{2}$ should be chosen to achieve the required secondary voltage?} \subtask{Does the steady-state duty cycle of the transistor need to be adjusted when the output power changes? Over what range must the transistor's duty cycle be adjustable, considering the input voltage range?} -\subtask{What is the maximum blocking voltage occurring across diode $D_\mathrm{1}$ and diode $U_\mathrm{DFs}$?} -\subtask{What should be the value of the primary inductance $L_\mathrm{p}$ to ensure - that the peak value of the magnetizing current remains below 10\% of the current $i_\mathrm{L'}$. - The current $i_\mathrm{L'}$ corresponds to the current $i_\mathrm{L}$ through the output inductance - at a nominal load of $P_2=\SI{125}{\watt}$, which is translated to the primary side. - (Assume $i_\mathrm{L}$ is approximately constant).} +\subtask{What are the resulting maximum blocking voltages of the diodes $D_\mathrm{1}$ and $D_\mathrm{2}$?} +\subtask{What should be the value of the primary inductance $L_\mathrm{1}$ to ensure + that the peak value of the magnetizing current remains below $\SI{10}{\percent}$ of the current $\overline{i_\mathrm{L'}}$. + The current $\overline{i_\mathrm{L'}}$ corresponds to the average current $\overline{i_\mathrm{L}}$ through the output inductance + at a nominal load of $P_2=\SI{125}{\watt}$, which is translated to the primary side.} \subtask{Sketch the waveform of the voltage across the power transistor, the current through the demagnetization - winding, and the current through the freewheeling diode $D_\mathrm{Fs}$ + winding, and the current through the freewheeling diode $D_\mathrm{2}$ for $U_\mathrm{1}=\SI{240}{\volt}$ and $U_\mathrm{1}=\SI{360}{\volt}$.} \subtask{Calculate the peak value of the magnetizing current for each case. Consider the current in the output - inductance as ideally filtered.} -\subtask{Could a higher power be transferred by doubling the switching frequency of the converter?} + inductor as ideally filtered.} +\subtask{Could a higher power be transferred by doubling the switching frequency of the converter?} \ No newline at end of file From d666b76bff1d974febce5beac0a96ff37f938f12 Mon Sep 17 00:00:00 2001 From: SevenOfNinePE Date: Mon, 25 Nov 2024 12:41:20 +0100 Subject: [PATCH 2/2] Small correction due to task3: Name of current thought L4 --- exercise/tex/exercise04.tex | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/exercise/tex/exercise04.tex b/exercise/tex/exercise04.tex index be9520f..8819d5f 100644 --- a/exercise/tex/exercise04.tex +++ b/exercise/tex/exercise04.tex @@ -150,7 +150,7 @@ \input{./fig/ex04/Fig_SingledEndedForwardConverter} The parameters are listed in \autoref{table:Ex04_Parameters of the singled ended forward converter.}. -The output inductance is dimensioned so that the current $i_\mathrm{L}$ exhibits a continuous waveform. +The output inductance $L_\mathrm{4}$ is dimensioned so that the current $i_\mathrm{L4}$ exhibits a continuous waveform. The transformer's leakage inductance can be neglected. \input{./fig/ex04/FigTab_SingledEndedForwardConverter} @@ -163,8 +163,8 @@ Over what range must the transistor's duty cycle be adjustable, considering the input voltage range?} \subtask{What are the resulting maximum blocking voltages of the diodes $D_\mathrm{1}$ and $D_\mathrm{2}$?} \subtask{What should be the value of the primary inductance $L_\mathrm{1}$ to ensure - that the peak value of the magnetizing current remains below $\SI{10}{\percent}$ of the current $\overline{i_\mathrm{L'}}$. - The current $\overline{i_\mathrm{L'}}$ corresponds to the average current $\overline{i_\mathrm{L}}$ through the output inductance + that the peak value of the magnetizing current remains below $\SI{10}{\percent}$ of the current $\overline{i_\mathrm{L4'}}$. + The current $\overline{i_\mathrm{L4'}}$ corresponds to the average current $\overline{i_\mathrm{L4}}$ through the output inductance at a nominal load of $P_2=\SI{125}{\watt}$, which is translated to the primary side.} \subtask{Sketch the waveform of the voltage across the power transistor, the current through the demagnetization winding, and the current through the freewheeling diode $D_\mathrm{2}$