Dynamic braking is the use of the electric traction motors of a railroad vehicle as generators when slowing the vehicle. It is termed Rheostatic if the generated electrical power is dissipated as heat in brake grid resistors and Regenerative if the power is returned to the supply line. Dynamic braking lowers the wear of friction braking components and additionally Regeneration can also lower energy consumption.
Yard locomotives with onboard energy storage systems which allow the recovery of some of this energy which would otherwise be wasted as heat are now available. The Green Goat model, for example, is being used Canadian Pacific Railway, BNSF Railway, Kansas City Southern Railway and Union Pacific Railroad.
Although blended braking combines both dynamic and air braking, the resulting braking force is designed to be the same as what the air brakes on their own provide. This is achieved by maximizing the dynamic brake portion and automatically regulating the air brake portion as the main purpose of dynamic braking is to reduce the amount of air braking required. This conserves air and minimizes the risks of over-heated wheels. One locomotive manufacturer, EMD, estimates that dynamic braking provides between 50% to 70% of the braking force during blended braking.
UL recognized dynamic braking resistors: enabling motor drive manufacturers the opportunity to offer the complete UL solution. (Special Report: Motors & Motion Control Subsystems).
Mar 01, 2003; Understanding the UL Terminology When searching for industrial components, a consideration must be given to the agency...
US Patent Issued to Fanuc on Nov. 8 for "Motor Drive Apparatus Equipped with Dynamic Braking Circuit Fault Detection Capability" (Japanese Inventors)
Nov 11, 2011; ALEXANDRIA, Va., Nov. 11 -- United States Patent no. 8,054,015, issued on Nov. 8, was assigned to Fanuc Ltd. (Minamitsuru-gun,...