在 RLC 串联交流电路中，流经电感元件与电容元件的电流为同一电流。由于电感电压超前电流90°，电容电压滞后电流90°，所以每时每刻，电感电压总与电容电压相反。当两电压幅值相等（感抗等于容抗）时，其电压叠加值为零，即电感与电容构成的整体可等效视为短路。此时依据欧姆定律，电路电流可直接表示为电压与电阻的比值，且电压与电流相位一致。需注意，电感与电容两端各自存在端电压，其数值可能远高于输入电压，此现象即被定义为串联谐振过电压。

What is the principle of series resonance?

In an RLC series AC circuit, the current flowing through the inductive and capacitive elements is the same current. Due to the inductor voltage leading the current by 90 ° and the capacitor voltage lagging the current by 90 °, the inductor voltage is always opposite to the capacitor voltage at all times. When the amplitudes of two voltages are equal (inductance equals capacitance), the voltage superposition value is zero, which means that the whole composed of inductance and capacitance can be equivalently regarded as a short circuit. According to Ohm's Law, the current in a circuit can be directly expressed as the ratio of voltage to resistance, and the voltage and current phases are consistent. It should be noted that there is a terminal voltage at both ends of the inductor and capacitor, which may be much higher than the input voltage. This phenomenon is defined as series resonant overvoltage.