Quench protection device of superconducting magnet system and working method thereof

A working method of a quench protection device of a superconducting magnet system, comprising:

• 1) presetting a voltage at two ends of a superconducting coil set via a preset module;
• 2) detecting, by a detection module, a voltage at two ends of two superconducting coils, comparing and determining, by a determination module, based on the detected voltage and the preset voltage, and determining whether the two superconducting coils are in a quench state;
• 3) when the two superconducting coils are in an excitation state at which two ends of the protection diode have a low voltage, and a current is not allowed to be conducted in the protection diode, conducting the current via the superconducting coil set, and controlling a change-over switch to be connected with a power supply by a control module to form an excitation circuit;
• and
• 4) when the two superconducting coils are in a quench state, since the voltage at two ends of the protection diode is increased, conducting the current by the protection diode to shunt the current in the superconducting coil set;
• controlling the change-over switch to be switched to connect with an external resistor by the control module to form a demagnetization circuit, so that the superconducting magnet system is protected;
• wherein when a ratio of the voltage at the two ends of the two superconducting coils to the preset voltage is in a range of 0.48-0.52:1, the two superconducting coils are determined to be in an excitation state;
• when the ratio of the voltage at the two ends of the two superconducting coils to the preset voltage is not in the range of 0.48-0.52:1, the two superconducting coils are in a quench state.