PS & OHE

The Chennai Metro Rail (CMRL) plays a vital role in reducing the city’s carbon footprint through efficient electrification systems, particularly Power Systems and Over Head Equipment (PS & OHE). These systems are integral in providing a reliable power supply for metro operations. They are composed of three subsystems: Power Systems, Over Head Equipment Systems, and the Supervisory Control and Data Acquisition (SCADA) system.

Power Systems

Power Systems in CMRL cater to two primary categories of loads: Traction Loads and Auxiliary Loads.

Traction Loads involve the rolling stock, powered through the Traction Power Supply. This includes major equipment such as Traction Transformers and Traction Substations (TSS).

Auxiliary Loads include all other electrical loads within the stations, excluding rolling stock, powered through the Auxiliary Power Supply. This system consists of Auxiliary Transformers and Auxiliary Main Substations (AMS).

Both systems are housed within Receiving Substations (RSS), which receive power from the Tamil Nadu Generation and Distribution Corporation (TANGEDCO) Grid Substations at a high transmission voltage of 110 KV. This power is then stepped down to 25 KV for traction loads and 33 KV for auxiliary loads.

In CMRL RSS, located at Koyambedu, Alandur, and Chennai Central to feed power to train operations. Below is the Power Supply layout in each RSS.

Over Head Equipment System

The OHE system provides power to the rolling stock via a contact with the train’s pantograph. Chennai Metro uses three types of OHE systems:

• Flexible Over Head Conductor System (FOCS): Used in elevated systems, it features a flexible conductor wire supported by a catenary wire.
• Rigid Over Head Conductor System (ROCS): Used in underground tunnels where space constraints require a rigid rail for power transmission.
• Tramway Type Over Head Conductor System: Used in depots where trains move at slower speeds.

SCADA System

The SCADA system is crucial for remote monitoring and control of the PS & OHE systems. The Traction Power Controller (TPC) at the centralized Operational Control Center (OCC) can manage the system.

Latest Technologies in PS & OHE Systems

To address power quality issues, particularly harmonics generated by power electronic loads, CMRL has installed Dynamic Power Compensation Systems (DPCS) at the 25 KV level in each RSS. This system mitigates harmonics to maintain them within acceptable limits and serves as a reference for other metro systems in India.

By implementing these advanced systems and technologies, Chennai Metro Rail not only enhances operational efficiency but also contributes significantly to environmental protection through reduced emissions and energy consumption.

கடைசியாக புதுப்பிக்கப்பட்டது : August 3, 2024