High accuracy and rapid speed measurement circuit of wide range current in power system

The utility model discloses a high accuracy and rapid speed measurement circuit of wide range current in a power system. The circuit comprises a current transformer, a signal conditioning circuit, a limiter, an A/D converter and a CPU, wherein the current transformer, the signal conditioning circuit, the limiter, the A/D converter and the CPU are sequentially connected. The signal conditioning circuit comprises a preamplifier, a main amplifier and a self-adaptive amplifier, wherein the preamplifier, the main amplifier and the self-adaptive amplifier are sequentially connected. The preamplifier is connected with the current transformer. The self-adaptive amplifier is connected with the limiter. A node between the main amplifier and the self-adaptive amplifier is connected with three branches. Each branch is provided with an average extraction circuit and a voltage comparator, wherein the average extraction circuit and the voltage comparator are sequentially connected. The average extraction circuit is connecte