Wielokanałowy pomiar temperatury w układach przekształtnikowych

W artykule przedstawiono system wielopunktowego pomiaru temperatury półprzewodnikowych przyrządów mocy, wykorzystany w laboratoryjnym stanowisku badania rezonansowych układów przekształtnikowych. System jest szczególnie przydatny podczas badania nowych konfiguracji przekształtników. Dzięki monitoringowi temperatury, można bezpiecznie pracować na granicy osiągów przekształtnika. Zastosowanie proponowanego układu pozwala na szerszy zakres badań laboratoryjnych.

The multipoint temperature measurement system is presented in the paper. The system is implemented in the laboratory breadboard, used for investigation of new resonant power converters. The system measures temperatures of each semiconductor power devices in the laboratory breadboard, which allows to achieve better results and to improve evaluated converter topology. The information about each transistor and diode temperatures, clearly shows the power losses in each semiconductor power device. Any deviations from assumed values can signalize improper operation of a particular device or mistakes in control signals. Discussed system is especially useful during laboratory performance investigations of a new converter topologies. The temperature measurement is based on the digital temperature sensors operating with 1-wire communication bus. One of the attractive features of the 1-wire bus is that a device only needs two wires, namely data and ground. To accomplish this, such a digital sensor includes an capacitor to power it from the data line. However, in the proposed system, additional wires were implemented to supply the sensors. Such approach is better, when 1-wire communication is taking place in high electromagnetic interferences. Laboratory tests have proved this. Thanks to the multipoint temperature measurement and control, safe operation of the converter at its performance limit is possible. The proposed system is successfully implemented in the resonant DC-DC converter operating with frequency 500 kHz and with the output power equal 3 kW.