Application of DC Power Supply in Testing Superconducting Materials
Superconductors are conductors that have zero resistance and complete flux repulsion effects at a certain temperature. This characteristic sets them apart from all other conductive materials in that they do not lose energy or heat when current flows through them. If superconductors are used to make transformers, generators, motors, current limiters, and energy storage systems, efficient power grids and motors can be realized. Superconducting magnets made from superconducting coils can be used in magnetic resonance imaging and artificially controlled nuclear fusion and other fields. The antimagnetic properties of superconductors also make them an option for magnetic levitation trains.
The three main performance indicators of superconducting materials are the critical transition temperature (that is, the highest temperature for becoming a superconducting state), the critical magnetic field (that is, the minimum magnetic field that can destroy the superconducting state), and the critical current (the maximum current for the material to maintain a superconducting state).
Superconductor V-I Diagram
Four lead method test wiring diagram
Experiments found that when a current flows through a superconductor, the superconductor remains unimpeded and has an upper limit to the current, which is called the critical current of the superconductor. When the current passing through is greater than the critical current, the superconductor appears resistance. The higher the critical current of a superconductor means that the superconductor can withstand a larger current and is more superconductive. A basic method for measuring the critical current of a superconductor is the four-lead method, which applies a DC constant current power supply to the superconductor, and the current when the voltage appears is the critical current value. ITECH IT-M3900 series dc power supplies have the characteristics of high speed and high precision, and the built-in CC/CV priority function can better control the constant current output, which can meet the requirements of superconducting testing.
IT-M3900 series power supply includes IT-M3900B regenerative power system, IT-M3900C bidirectional programmable DC power supply and IT-M3900D high-power programmable DC power supply. Among all the models, the 1U model can reach 510A, the 2U model can reach 1020A, and the maximum current for parallel machines can reach 8000A, which is suitable for testing the critical current of superconducting products as well as ATE testing and building.
