Unterschiede

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--- professoren_webseiten:rebholz:course_a_power_electronics [2025/02/06 14:58] – [Reactive Current] hrebholz
+++ professoren_webseiten:rebholz:course_a_power_electronics [2025/03/06 20:59] (aktuell) – [Simulink] hrebholz
@@ Zeile 203: / Zeile 203: @@
 The power PCB is controlled with the help of a Simulink experiment. The microcontroller exchanges data cyclically with the PC via the serial interface.\\
+Dowload the lastes Simulink experiment to control the DIY Power PCB: {{ :professoren_webseiten:rebholz:vorlage_course_a_basis_v01_2021b.zip |Simulink Version 2021b}}
+{{ :professoren_webseiten:rebholz:control_pannel_simulink.png?direct&1000 |}}
-- Connection, COM- Port, Start, Stop
+If you can not establish a connection to the board double check the COM port settings.
+For safety reasons (PC protection) please always us an isolation device: [[https://wiki.ei.htwg-konstanz.de/professoren_webseiten/rebholz/diypowerpcb#isolation|Link]]
 ===== Before you start =====
@@ Zeile 419: / Zeile 422: @@
 The transition from the point at which current flows back out of the capacitor occurs from the so-called critical current mode. Here, the lower reversal point of the current is set on the zero line. If the load becomes even smaller, the current in the capacitor becomes negative and flows back to the source as reactive current.
+<WRAP center round todo 80%>
+**Task 16a**
+alculate the critical load resistance at which critical conduction mode (CRM) occurs.\\
+**Task 16b**
+Increase the load resistance until you can measure the CRM state. Check what happens if you increase the resistance further.
+</WRAP>
+Reactive currents are not always bad. They can be used to eliminate the reverse recovery of the body diode. If we exactly meet the CRM mode, there is even no switching loss because we turn on the low-side MOSFET at zero current. If it is possible to generate a small amount of negative current, we even have no switching losses at the high-side MOSFET, as it operates in zero-voltage switching. This type of power electronic circuit is called a resonant converter, and it is now commonly used in many applications. The theory behind resonant switching converters is part of the Master's course Power Electronic Systems." \\
-. Reduce the load current until critical current Mode
+The reduction of the reverse recovery effect can be seen by measuring the current through the MOSFETs with a Rogowski coil. If you don't have one, it is also possible to look at the drain-source voltage of the low-side MOSFET. \\
-. Reduce until discontinuous current mode and observe the output voltage
+{{ :professoren_webseiten:rebholz:reverse_recovery1.png?direct&600 |}}
+<WRAP center round todo 80%>
+**Task 17a**
+Consider and discuss with your neighbor why in this state the high side mosfet can be switched on at a voltage of less than 1V. This state is then referred to as ZVS zero voltage switching. \\
+</WRAP>
+<color #ffc90e>**Congratulations. Now you are ready and prepared for the exam!**</color>