HY-PLM adopts full linear analog power amplifier topology without SPWM switching harmonics or RF leakage, ultra-clean sine wave THD＜0.5% (45~500Hz linear load), far superior to switching medium-frequency supplies, avoiding interference with LCR meters, impedance analyzers, NMR and weak-signal sensors. Standard band 320~480Hz (GJB181A military 400Hz aviation standard), optional extended wide band 45Hz~5kHz, single/three-phase output available. Each A/B/C phase voltage adjustable independently 0~rated value, inter-phase angle fine-tunable 0~359.99° in 0.01° steps, accurately simulating balanced/unbalanced airborne medium-frequency grid and special precision equipment power conditions