Method and apparatus to control operation of a hydraulic control circuit for an electro-mechanical transmission

摘要

A method and an apparatus for controlling an electro-mechanical transmission selectively operative in a plurality of fixed gear modes and continuously variable modes is provided. The exemplary transmission comprises first and second electrical machines and a hydraulic circuit comprising a plurality of pressure control devices and flow management valves. The method comprises monitoring an operating temperature of the electrical machines. A cooling flow rate in the hydraulic circuit effective to reduce the operating temperature of the electrical machines is determined. Availability of active cooling for each of the electrical machines is determined. Hydraulic flow in the hydraulic circuit is selectively controlled.