Speaker
Description
The meat grinder with SECT circuit is a basic circuit for inductive pulsed power supply. When it comes to a practical electromagnetic launch system, collaborative work of multiple modules is necessary. This paper discusses the performance feature of two meat grinder with SECT modules in Fig. 1 which are charged in parallel by $C_0$ and then discharge in parallel to load with different time sequences.
Firstly, appropriate triggering delays of two modules are designed. To reduce the magnetic field coupling between the two modules, thyristor $T_{11}$ and $T_{21}$, $T_{12}$ and $T_{22}$ are triggered at the same time respectively. Afterwards, in previous research, a relatively high ratio of $L_{i1}$ and $L_{i2}$ lead to large second current peaks. As a result, $T_{13}$ is triggered exactly when pulse-forming capacitor $C_1$ is fully reversely charged. The only adjustable trigger time is $T_{23}$. However, for other applications, the ratio of $L_{i1}$ and $L_{i2}$ is smaller. So the second current peak of the load is small. In this paper we determine the best trigger times of $T_{13}$ and $T_{23}$ to make sure that the load current form is the most similar to a rectangular waveform.
Secondly, if the trigger time of $T_{22}$ is later than that of $T_{12}$, according to the simulation results, there will be a high overvoltage across $T_{11}$ when $T_{22}$ is triggered. This overvoltage could be reduced by cascading a protection inductor with $T_{21}$. And this method could be extended to cases of multiple meat grinder with SECT modules, i.e., all modules need the protection inductor except the module which have the earliest trigger time of $T_{i2}$. As it is hard to guarantee that the switches work simultaneously in engineering practice, applying protection inductors to all modules is necessary to ensure the reliability of the system.
