Capacitor AC voltage sampling device and capacitor protection device

The embodiment of the invention provides a capacitor alternating-current voltage sampling device and a capacitor protection device. The capacitor alternating-current voltage sampling device comprises three groups of voltage transformers, wherein each group of voltage transformers comprises a primary coil and two secondary coils; the two ends and the center tap of the primary coil are used for being connected with the secondary side corresponding ports of the capacitor discharge coils of the corresponding phases respectively. The non-polar ends of the two secondary coils are grounded, and the polar ends of the two secondary coils output acquisition voltage of the dotted terminal of the primary coil, so that voltage values of the capacitors of the corresponding phases are correspondingly output through the polar ends of the two secondary coils; therefore, the voltage value of each phase capacitor can be detected in real time, and the fault detection efficiency of the capacitor is improved. 本发明实施例提供了一种电容器交流电压采样装