Although they themselves do not generate arcs during operation, SSPCs cannot avoid other possible arcs, such as aircraft cables. Therefore, SSPCs are no longer satisfied with their existing functions, and they are actually still substitutes for traditional protection devices, placing higher demands on arc fault detection. Due to the increase in total impedance of the load and the inability of the circuit breaker to respond promptly to small current faults, series arc faults are considered more dangerous. 5. Therefore, this article focuses on the detection of series AC arc faults. Reconstruct the fault half cycle data using these two methods, and perform frequency domain analysis on the fault half cycle data using Fast Fourier Transform (FFT) and Wavelet Packet Decomposition (WPD), respectively, to evaluate the accuracy of the two methods.

SSPC is a semiconductor device used to control the supply of power to a load. The basic block diagram of AC SSPC is shown in Figure 2. They perform monitoring and diagnostic functions to prevent overload and short circuit. A typical SSPC consists of the following components: main power supply equipment, drive circuit, signal conditioning circuit, short-circuit protection circuit, and CPU module. This new type of intelligent switch is different from traditional switching devices such as contactors and relays because it uses static switching devices (such as MOSFETs, IGBTs, or JFETs) to control through a microcontroller. This microcontroller directly measures the output current through a sensing resistor and also allows for remote activation or deactivation of SSPC status. SSPC opens or closes circuits based on commands issued by the CPU and operates safely in the event of CPU failure. It not only protects electrical equipment from the effects of short circuits and overloads, but also protects the power lines of the I2t curve within the short-circuit limit, making full use of the thickness of aircraft cables. Figure 3 shows multiple channels integrated onto a PCB board. Multiple SSPC boards will implement the functional units of the Electric Load Management Center (ELMC)