Thyristor Controlled Rectifiers (TCRs)

Thyristor Controlled 12-pulse Rectifiers (TCR) manufactured by Pluton are a modern solution for metro, light rail, as well as urban electric transport and railways traction networks modernization.

Thyristor Controlled Rectifiers provide constant voltage on substation busbars over a wide range of traction loads, taking into account AC network fluctuations.

Effectiveness of Thyristor Rectifiers application for powering traction networks with regulated voltage makes it possible to develop new flexible solutions that can be adapted to the most diverse Customers’ needs.

Application of TCR to power electric transport traction networks has a number of benefits over standard diode systems.

power saving in traction network

adaptability to any Customer's technical requirements

materials and components by global manufacturers

control and regulation system of the new generation

Benefits:

DC traction network voltage regulation, and thus energy savings (reduction of losses) in the traction network
implementation of electronic current protection leads to reduction in surge currents at the rectifier output;
possibility of power and load control system implementation with online parameters setting in remote control system;
reduction of traction substations number when designing a new line, thus reducing construction costs;
possibility to increase the line capacity or to use more powerful trains, when modernizing existing substations with diode rectifiers.

Design features
WITHDRAWABLE THYRISTOR RECTIFIERS
DESIGN (withdrawable rectifiers)
Control system
traction network protection

Depending on power, a Thyristor controlled fixed rectifier includes one or two cabinets with power thyristors, fuses, protection, control and monitoring components. It is supplied by a dry three-winding converter transformer.

Tablet power thyristors are used in the rectifier. High-speed power fuses are installed in series with each thyristor to provide protection against internal short circuits. Cooling is natural air.

The rectifier also provides protection of power semiconductor devices against internal and external switching overvoltages. Protection against internal switching overvoltages is provided by RC circuits, against external overvoltages - in combination: RC circuits and varistors.

Withdrawable thyristor rectifiers are designed for construction of urban electric transport traction substations with load current electronic switching. These devices include rectifier and switchgear functions.

Thyristor rectifiers provide switching of a wide range of load currents without electromechanical system and without an arc, i.e. electronic switching is achieved by thyristors opening pulses removing.

Benefits:

power supply from the rectifier to the load is fully controlled in all operating modes;
implementation of “line test” function in traction network without additional equipment;
easy inspection and maintenance due to application of withdrawable component;
no plasma emission at short-circuit currents interruption, since the switching is done with thyristors, as a result - no combustion products and their deposits;
reduction of fire hazard due to absence of plasma generation open sources.

Withdrawable thyristor rectifier is based on standard arrangement of separate compartments common for many switchgear units:

automation and control compartment - low-voltage compartment with control and diagnostic system components;
withdrawable unit compartment - power part of thyristor rectifier;
busbar compartment - includes AC and DC busbars. The compartment is divided into several isolated compartments, allowing safe access for power cables maintenance even under voltage on power busbars.

Division into compartments also allows safe maintenance of high-voltage measuring circuits and standby disconnector, located in busbar compartment.

Withdrawable unit has three positions:

operating;
control;
maintenance.

Withdrawable unit moves automatically from operating to control position with the help of low-power electric drive, without any effort from the operating personnel. At the same time, operational safety is guaranteed by electromechanical interlocks system and organizational measures.

The rectifiers are equipped with microprocessor control and diagnostic system based on SOTA® controller, conforming to IEC 61131 series of PLC standards and supporting IEC 61850 protocol.

MC-POWER module is connected to SOTA® controller to control thyristor bridge.

HMI is provided by an operator panel in the form of 7-inch TFT touchscreen display, allowing the user to exchange data with the control system. Operator's panel provides:

output of operation mode messages;
output of warning and emergency messages;
selection of rectifier control mode;
setting, change and saving of parameters settings;
rectifier event logging;
testing of separate rectifier units;
connection of rectifier with telecontrol system.

Withdrawable rectifiers are equipped with microprocessor control and diagnostic system based on SOTA® controller and MC-POWER module.

Similar to traditional switchgear, withdrawable thyristor rectifiers protect traction network by continuous monitoring and analysis of current and voltage variations dynamics in traction network and issuing rectifier tripping commands in case protective functions set parameters are exceeded.

SOTA® control system generates and saves two types of fault waveforms (current and voltage waveforms) each time one of protections trips: