Study on the Topology and Control Method of a Power Supply for Temperature Field Test of High-frequency Transformer

Temperature field testing is an important part of testing the design quality of high-frequency transformers in power electronic transformers (PET) or isolating DC-DC converters. The test process requires reproducing the application scenarios of high-frequency transformers and at the same time reducing the power consumption of the test power as much as possible. To this end, this paper designs a DC power feedback type high-frequency transformer temperature field test power supply. The power supply is mainly composed of power frequency AC-DC and back-to-back high-frequency transformers, DC-AC and AC-DC modules. Power diodes and resistors are connected in series with high-frequency AC-DC and DC-AC DC sides to form a DC power feed link. The sum of the high-frequency DC-AC DC voltage and the DC feeding resistance voltage is used as the set value of the high-frequency AC-DC DC voltage output., and the single-phase shift of DC-DC control is adopted to achieve the target current output of the test power supply. At the same time, a mathematical model between the input and output current of the test power supply and the grid-side current is established, which provides a theoretical basis for the energy-saving evaluation of the energy feedback test method. Finally, the test power supply experiment simulation system was built, and the results confirmed the correctness of the test plan.