High-power DC power supplies are rarely encountered in everyday life, but they are surprisingly close to us. For example, in high-speed trains that we frequently travel on, the application of high-power DC power supplies can be observed during operation.
High-Speed Train Braking Systems: Slow-speed trains primarily employ brake shoes for braking, which utilize friction with the steel tracks. High-speed trains (over 300 km/h) use eddy current braking, involving lowering a set of electromagnets within 10 centimeters of the steel tracks, then applying power. This generates eddy currents between the electromagnets and the tracks, resulting in heat, which dissipates kinetic energy as thermal energy to slow down the train. The advantage of this braking method is that it is unaffected by increased speed at high speeds and can maintain a higher braking force. The drawback is that the large amount of heat generated can lead to track overheating, necessitating time for cooling and heat dissipation.
The braking module testing bench requires power supply to the electromagnet, coordinating with a tensile sensor, temperature sensor, infrared rangefinder, as well as auxiliary power and auxiliary hydraulic lifting devices for the integrated control of the entire test bench via a host computer. The experimental process sets the initial distance of the braking device rail, applies different voltage and current values from the power supply, measures the change in distance and the resultant tensile force, and obtains the experimental results for evaluating the braking performance. Aviation Power
During the energization test of the electromagnet, since the main power supply for the electromagnet on the train is a constant current source, and the backup power supply is a constant voltage source, the power supply needs to operate in both constant voltage and constant current modes during testing. The impedance of a single coil is 0.4~0.5Ω, and the test requires 3~4 series-connected energization tests. The IT6500C series power supply is used as the power supply for the electromagnet, featuring CC and CV operating modes, adjustable loop speed, and priority settings. During actual testing, a setting of 500V and 100A resulted in an actual output of 100V and 100A, with the power supply operating in CC mode. When operating in CV mode, due to the electromagnet being an inductive load, it can easily cause loop voltage oscillation. By setting the CV loop speed to low, the power supply can maintain a stable constant voltage output. Additionally, the open bottom protocol makes it easier for users to integrate and complete secondary development.
