Braking system for electric railcars including means for controlling electric brake force

摘要: A braking system for an electric railcar having a.c. motor with a variable voltage frequency inverter. The inverter controls the and supplied to in response speed, commands from cab, load conditions, etc. also includes pneumatic brake which operates at low speeds. control circuit supply down slow speed then simultaneously applies braking, smoothly increasing force until stops. During transistion maintains output vicinity of 0 Hz, keeping voltages positive phase range.