Electronic Governor is a maintenance free alternative to the mechanical Governors popularly used for this application. The Governor consists of a Control Unit mounted in the Driver cab, and an Actuator Unit mounted on the Engine. The Actuator Unit can be mounted exactly on the same Engine base as mechanical Governors. The Governor controls the engine speed, based on throttle handle position (popularly known as notch) selected by the Driver on the Driver Desk. Engine RPM is measured from a Tachogenerator or speed sensor mounted on the Engine. Digital PID control is used to calculate desired fuel rack position dynamically, based on the selected notch on throttle handle and measured Engine RPM. A Stepper motor drive is used in the Actuator Unit to control the fuel rack of Diesel Engine. The Governor also controls load on the engine electrically, to limit horsepower at each notch to a pre-set level, through an electrical interface with the excitation system of Locomotive. Booster (Turbo) air pressure is measured through a pressure sensor mounted in the air manifold. Movement of fuel rack is limited as a function of this pressure to prevent incomplete combustion of fuel, black smoke, excessive engine temperature, fuel wastage etc caused by lack of air to burn the fuel. Lube oil pressure is continuously monitored and Engine is shutdown if the lube oil pressure is less than the specified pressure at each notch position. This protects the Engine from damage due to malfunction of lube oil pump etc.
The system displays status of various engine parameters continuously on the Vacuum Fluorescent Display. The system has built in fault diagnostic facility. In case of any fault, it takes appropriate action immediately, displays relevant fault message on the display for information to the driver, and also records the fault with date and time stamp, to help the maintenance crew later for analysing the root cause. The Governor has number of user programmable parameters, which permits the system to be used on various types of engines/locomotives. Configuration of the system through user settable parameters for fine tuning of operation and reading fault messages of Error Log can be done, on-line on the locomotive, using a laptop PC, even while the engine is running. The equipment is modular in construction and has functionally separated plug in modules for ease of repair and maintenance.
More than 3500 units have been installed on Diesel Electric Locomotives of various designs on Indian Railways and other railways. Indian Railways currently fits Microcontroller based Governors on all new and retrofit Diesel Locomotives. Apart from new built Locomotives, Indian Railways have taken up a healthy retrofit program to upgrade more than 200 locomotives per year with Microcontroller based Governors. Medha is a market leader in these systems with over 99% market share. Medha's Governor can be installed in place of an existing Governor.
Vision & Mission
To be World Leader in Railway Products
Enjoying Innovation and Applying Technology for improving the lives of people.
Enhancing the image of India in the world, in high technology.
R & D CentreMEDHA SERVO DRIVES PVT. LTD. 2-3-2/A,
Behind Mint Compound, Cherlapally, R.R.Dist,
Hyderabad - 500 051 Telangana, India.
Phone: 91-40-6723 7000; Fax: 91-40-2726 4144
MEDHA SERVO DRIVES PVT. LTD. P-4/5B, IDA, Nacharam, Hyderabad - 500 076 Telangana, India
Phone: 91-40-2717 1101; Fax: 91-40-2715 4706