By sion932 
In fact, the series resonance and parallel resonance that we have learned about are both common and specific phenomena in selected AC circuits, and they are commonly used in some electronic and communication devices. However, using resonance in electricity can seriously disrupt the normal operation of all systems. Next, let’s briefly introduce the differences between these two different resonances.
Difference 1: In the process of using series resonant devices, the circuits they are responsible for are basically low impedance power supply modes. However, if there is an inverter failure during use, a large current will surge in in a short period of time, making it difficult to achieve protective effects. However, in the process of using parallel resonance, in the event of inverter failure, the current generally does not cause too much impact.
Difference 2: Series resonance generally presents constant voltage currents during use, and corresponding power supply values are input during use. And during use, it must be at a frequency lower than the operating frequency of the load circuit, so basically all supply frequencies are fixed during use. Parallel resonance mainly uses constant current in the process of use, so the operating frequency in the circuit is generally slightly higher than the natural frequency of the load.
Difference 3: Series resonance generally causes the thyristors to naturally close during use. After the power is cut off, the current gradually decreases to zero, so the entire closing time is relatively short, which can also minimize losses to the greatest extent possible. When using parallel resonance, it is always forced to shut down, so there is usually some back pressure time after a sudden stop, which is relatively longer.