Traction Converter Cubicle Overview

A fully assembled unit containing the traction control unit (TCU) which manages the power conversion from AC or DC to power the traction motors.

The input voltage range acceptable by the traction converter in AC mode. This range corresponds to a line voltage from 16.5 to 28.5 kV.

The nominal DC voltage level present on the DC link circuit during traction operation.

The traction converter can operate with both DC or AC power input.

A power electronic device responsible for converting DC power to AC power for driving the traction motors.

Siemens’ Traction Control Unit (TCU) that controls and monitors the function of the traction converter.

The traction converter uses a combination of DC and AC power to run electric trains.

A key component of the traction converter, responsible for converting AC input voltage into a controlled DC voltage for the DC link circuit.

A circuit that acts as a bridge connecting the 4QC to the inverter, holding a steady DC voltage for the traction motor.

A safety feature that detects and protects the circuit against potential earth faults, using capacitors to monitor the system.

The process of gradually charging the DC link capacitor before activating the main contactor, preventing sudden surge currents.

A device that converts DC power into AC power, controlled by pulse-width modulation to regulate the motor's speed and torque.

A crucial component responsible for braking by converting kinetic energy from the train into electrical energy. This energy is then directed back to the DC link

A double-pole contactor that isolates the transformer and 4QC module from the traction winding, ensuring safe operation and connection.

IGBTs are used as high-speed switches in a traction converter, turning on and off rapidly to regulate the flow of current in the DC link circuit.

The IGBTs are triggered in sequence to create a 'freewheeling' effect, where current flows through a diode after the IGBT is turned off, preventing sudden voltage drops.

A four-quadrant chopper module is a power electronics device that can control the direction and magnitude of power flow, enabling both motoring and braking operations.

The PWM inverter allows for precise control of the AC voltage and current delivered to the traction motors by rapidly switching the DC link voltage.

The PWM inverter adjusts the phase relationship between voltage and current in the traction motors, allowing for the control of motor speed and torque.

The maximum output voltage of the PWM inverter is limited by the DC link voltage, which is the voltage level across the DC link capacitor.

The output voltage of the PWM inverter is effectively reduced by periodically turning off the IGBTs for brief periods, creating a 'clocked' waveform.

Braking in an electric train involves reversing the direction of motor torque, which can be accomplished by shifting the phase relationship between voltage and current.

The SIBAS® 32S is a Traction Control Unit (TCU) developed by Siemens that manages the power conversion and controls the traction converter.

The PWM inverter uses the DC link voltage to create AC voltage for the traction motors. This voltage can be manipulated to control speed and torque.

The Pulse Width Modulated Inverter (PWMI) is a power electronic device that converts DC power to AC power for driving traction motors. It uses a pulse-width modulation technique to control the output voltage and frequency.

Each traction converter cubicle (TCC) is equipped with two PWM inverters. Each inverter controls two traction motors.

Insulated Gate Bipolar Transistors (IGBTs) are used as semiconductor devices in the PWMI, allowing for efficient switching and power control.

The phase modules in the PWMI use the SIBAC® BB S P 1500 FL type, a specialized component for high-power applications.

The PWMI operates at a variable frequency, up to 800 Hz. This allows for flexible control of the traction motors.

A brake chopper helps to stop the train by converting energy from the traction motors to heat.

Each TCC has two brake choppers, working in conjunction with the PWM inverters for efficient braking.

The brake chopper uses IGBTs, like the PWMI, for controlled switching and energy dissipation.

The SIBAC® BB S P 1500 FL type phase modules are also used in the brake chopper, ensuring consistent performance and reliability.

The brake chopper operates at a fixed pulse frequency of 250 Hz, allowing for reliable and controlled braking.

The power required for the train to operate continuously, measured in kilowatts (kW).

The ability of the system to handle a short-term surge in power requirements, typically for a short duration like acceleration.

The traction converter cubicle (TCC) is a fully assembled unit housed in the high-voltage compartment of the train. It contains key components like the traction control unit (TCU), inverters, and choppers.

The traction converter operates with both AC and DC power inputs. It can handle a voltage range of 627-1083V AC (16.5-28.5kV line voltage) and 800-1800V DC. This flexibility ensures smooth operation across different power sources.

The TCC uses two four-quadrant choppers (4QCs) to control power flow. Each 4QC converts AC or DC input to a controlled DC voltage for the DC link circuit.

The DC link acts as a bridge between the four-quadrant choppers and the inverters, ensuring a steady DC voltage for the motors. It uses capacitors to store energy for smoother operation.

The PWM inverters are responsible for converting DC power from the DC link into AC power for the motors. They use a pulse-width modulation (PWM) technique for precise control of speed and torque.

The SIBAS® 32S traction control unit (TCU) is a sophisticated system from Siemens that manages the TCC, monitors its performance, and ensures safe operation.

The TCC uses two brake choppers to convert the kinetic energy of the train into electrical energy during braking. This energy is then fed back to the DC link for reuse or dissipation.

The IGBTs act as high-speed switches, controlled by a sequence that alternates between them for even thermal distribution, to build up current in the transformer's inductance.

Each traction converter cubicle (TCC) is equipped with two PWM inverters.

The traction converter performs pre-charging of the DC link capacitor before activating the main contactor (K1). This prevents sudden surges of current when the input voltage is applied, ensuring a smooth and safe start-up.

The 4QC transforms AC input voltage (from the transformer) into a controlled DC voltage for the DC link circuit. This DC voltage is then used by the inverter to power the traction motors.

Capacitive Earth Fault Registration is a safety feature that uses capacitors to detect and protect the system against potential earth faults. It's a critical protection mechanism for the traction converter and the entire train system.

The DC link circuit acts as a bridge between the 4QC and the inverter. It holds a steady DC voltage that is used by the inverter to generate AC power for the traction motors

The PWM inverter controls the motor speed and torque by rapidly switching the DC link voltage. This creates a variable AC output voltage that powers the traction motors.

The IGBTs are used as high-speed switches within the traction converter. They turn on and off rapidly to control the flow of current in the DC link circuit, allowing precise modulation of power.

The braking chopper converts the train's kinetic energy into electrical energy when the train needs to slow down. This energy is then directed back into the DC link circuit.

The main contactor (K1) isolates the transformer and 4QC module from the traction winding. This ensures safety during operation and allows for controlled connection and disconnection of power.

The pre-charging resistor helps in gradually charging the DC link capacitor before the main contactor (K1) closes. This controlled charging prevents high inrush currents, ensuring a smooth start-up and minimizing damage.

The Pulse Width Modulated Inverter (PWMI) converts DC power from the DC link to AC power, using a pulse-width modulation technique to control motor speed and torque. It has a variable pulse frequency of up to 800 Hz, allowing for flexible control of traction motors.

Each Traction Converter Cubicle (TCC) contains two PWM inverters. Each inverter controls two traction motors, ensuring smooth and powerful acceleration and deceleration.

The PWMI uses Insulated Gate Bipolar Transistors (IGBTs) as the semiconductor devices. These IGBTs allow for efficient switching and control of the power flow.

The PWMI phase modules utilize the SIBAC® BB S P 1500 FL type, which is designed for high-power applications. These modules manage the flow of electricity and provide robust operation.

The Brake Chopper is a key component in the system that converts kinetic energy from the traction motors into heat. This process helps to slow down and stop the train efficiently. During braking, it operates at a fixed pulse frequency of 250 Hz.

Each TCC houses two brake choppers, which work in partnership with the PWM inverters to deliver effective braking performance.

The brake chopper utilizes IGBTs like the PWMI, enabling controlled switching and energy dissipation during braking operations.

The DC link capacitor stores electrical energy, providing a stable voltage source for the PWM inverter and the brake chopper.

The DC Link Circuit is vital because it connects the 4QC (Four Quadrant Chopper) to the inverter. It maintains a steady DC voltage, enabling the efficient flow of electrical power to the motors.