Medha Servo Drives Pvt. Ltd., founded in 1984, is focused on rail transportation. Medha’s vision is to become world leader in railway products and to achieve this we specialize in three areas, Control Electronics, Power Electronics and safety critical Signalling.
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InnoTrans 2012
Products for Diesel Locomotives
Traction Converter
For Diesel / Electric locomotives, EMU and DEMU vehicles with AC Traction Motors, Medha's new Microprocessor based AC-AC Traction System (MAS) offers the latest in technology combining IGBT based Traction Converter with DSP and microprocessor based embedded controls. Microprocessor based Locomotive Control system is used in conjunction with IGBT based Traction Converter to implement this solution.
Locomotive Control Computer
- Improves Locomotive Availability (reduced down times)
- Improves Adhesion with Independent Motor Control philosophy
- Improves Engine Utilization (GHP based control)
- Monitors all Traction Equipment on-board for Safe Operating Margins
- Customizable parameter settings to adapt to different locomotive types without changing software
- Modular expandable platform for added functionality like Automatic Engine Start Stop, Remote Monitoring, Distributed Power Control etc for fuel savings, increased availability and monitoring.
Hotel Load
Medha has designed and developed HEP units for Diesel-Electric locomotives where primary power source is the 3phase Alternator coupled to the Diesel Engine. This HEP unit is rated for 500kVA load (typical power requirement of up to 10 coach trains). Due to lack of space on-board the Diesel locomotive, the HEP unit was designed to be an underframe unit with forced air cooling. Wires are run between coaches and the converter through highly reliable couplers used by the railways.
Medha is also working on concept design of two HEP units of 500kVA rating each for Electric Locomotives (1000kVA is power requirement of 20 coach train). The power source for this converter will be an auxiliary winding of traction transformer. This HEP unit is an on-board system with forced air cooling.
Locomotive Control System
Medha’s Microprocessor based Loco Control System Type MEP 660 uses state-of-art technology, for controlling diesel electric locomotives. This is a maintenance free alternative to the popularly used E type excitation for this application. This provides Excitation Control, Propulsion Control, Dynamic Braking Control, Wheel Slip Control, and Auxiliary Generator Control with digital PID controls.
Governor
Microcontroller based Governor MEG-601 uses state-of-the-art technology, for controlling Diesel Engine of Diesel Electric Locomotives. This is a maintenance free alternative to the hydraulic Woodward 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 Woodward Governors
More than 2000 units have been installed on Diesel Electric Locomotives of various designs on Indian Railways.
TFT Driver Display
Speed Recorder
Medha is one of the leading manufacturers of Speed Recorders for Railway applications. These recorders are used on Locomotives and are similar in function to Black boxes in aeroplanes. Speed Recorders are used for monitoring the performance of Loco Driver and especially in the event of an accident the recorded data becomes vital for establishing the cause of accident.
Medha designed it's first Speed Time Distance Recorder MRT 912 in 1989. It was an innovative technology in Strip Chart Recording using a microprocessor, developed as a substitute for the Secheron, Switzerland made mechanical Speed Recorder used by the Indian Railways at that time. It was the first microprocessor based system on the Indian Locomotives.
Distributed Power Control (DPC)
In DPC all the control and operating signals from the lead locomotive are transmitted to the distributed trailing locomotives through radio transceivers, so that all of them are run in synchronization with a single driver control from the lead locomotive.
This product is basically a control system which communicates with the same or similar control system fitted in other locomotive for synchronized running of the train formation.
Vehicle remote monitoring in real-time
Vehicle remote monitoring solution is an Internet based system connecting all locomotives in the field with centralized Locomotive Management System through CDMA and / or GSM network communication. This solution consists of:
Locomotive and Train Management System (LTMS)
A centralized server serves as repository for information received from locomotives through Internet. Information includes locomotive location, operational parameters, health status, fuel level data, fault logs and related information, life-time counters and event recorder data. Authorized users can log into LTMS to view present and past information, analyze details of locomotive and plan for maintenance.
Locomotive Remote Monitoring System (LRMS)
LRMS is an on-board unit with interface to locomotive computer, GSM and/or CDMA communication devices and GPS receiver. This rugged system sends all locomotive information to LTMS at periodic intervals. LRMS can also be used as emergency voice communication device by driver.
