Early electric locomotives used "brush-type" AC/DC motors that operated much more efficiently at lower frequencies.
This specific frequency is a historical and technical standard used primarily for train traction. While most public power grids run at 50 Hz or 60 Hz, these railway systems operate at a lower frequency for several key reasons: low-frequency-16.7z
Small-signal models or HIL (Hardware-In-the-Loop) simulation results testing the stability of 15 kV / 16.7 Hz networks. Research Papers: Studies on the historical transition from it probably includes:
Hz to the modern 16.7 Hz standard to prevent synchronism issues in rotary converters. low-frequency-16.7z
If this archive contains technical or engineering data, it probably includes: