Innovations at InnoTrans 2024 for rolling stock and DC traction power supply

The world’s largest trade fair focused on the rail transport industry will take place in Berlin in September. The special highlight of the fair is the outdoor display with 3500 meters of track, where the rail vehicle manufacturers presents their products from high-speed trains to hybrid locomotives, from road-rail vehicles to trams.

Knick has been a partner for the German and international rail industry for more than 50 years. Knick’s precise, robust, and reliable high-voltage transducers and transmitters provide the required signals for downstream processes at all times without interference during traction power supply in substations or for current and voltage measurement, signal isolation and conversion on rolling stocks.

At InnoTrans 2024 Knick presents electrical measurement solutions for rolling stock and DC traction power supply applications.

High Isolation Transducers for Voltage, Current and Speed Signal

P16800 – Speed Signal Doubler with SIL2/SIL4 for using encoders more effectively

Many systems on rail vehicles rely on accurate speed information. However, free axle ends and installation space for speed sensors are limited and their sourcing, installation, and maintenance entail considerable expense.

The P16800 signal multiplier from Knick doubles the signals of a speed sensor. The original signal is free from interference up to SIL 4 and the duplicated signals can be transmitted functionally safe in SIL 2 safety circuits. If necessary, the P16800 improves the signal quality of a deformed output signal. The device converts current into voltage and voltage into current, allowing for a variety of encoders to be connected to different control systems.

Individual speed sensors are thus available for several different system controls, for which it makes no difference whether an encoder is connected directly or via the P16800. The P16800 is the ideal solution for retrofitting rail vehicles. The device helps to quickly and cost-effectively implement the extensive requirements for odometry that result from the European standardized train control system ETCS.

P45000 –  The most space-saving High Voltage Transducer up to 4500 V DC and 3000 V AC with SIL 2 for Rolling Stock

Knick has developed the P45000 high-voltage transducer for DC voltage measurement on-board trains for all DC and AC powered rolling stock.

It is especially designed for space-saving and flexible (lying or upright; screw fastening or DIN rail mounting) installation in traction inverters and auxiliary power converters. The P45000 has mechannterface-technoloical and electrical interfaces that are customary in the rail industry, which allows its usage without major design changes.

The device is designed for measurements of DC voltages up to 4500 V DC and AC voltages up to 3000 V AC with a type test voltage of up to 20 kV AC. It is thus suitable, for example, for measurements on DC intermediate circuits and DC inputs in drive systems on rail vehicles. The P45000 protects against dangerous body currents up to an insulation voltage of 3700 V AC/DC and, in the variant with fixed cable connection, up to an insulation voltage of 4800 V AC/DC. The  P45000 is ready to order with any input vorltage range.

P41000AG  – Two-in-One: Nominal Current und Overcurrent Measurement

The P41000AG (AG = Adaptive Gain) transducer is designed in such a way that, in addition to regular currents, it can also measure high overload currents caused by short circuits or overloaded motors. This eliminates the need for an additional transducer to measure these overload currents as well as an additional measuring channel for a downstream control device.

To detect both regular and overload currents, the transmission characteristics of the P41000 AG is divided into two different areas. The first part represents the nominal range of the gain in regular operation with 0 to ±100 percent of the rated current from 4 to 16 mA. The second part is the overload range from ±100 to ±1100 percent of the rated current, which is converted at the output of the P41000 AG into 16 to 24 mA.

With its special transmission function, the P41000 AG is aimed at applications in which overcurrents have not yet been measured for cost reasons or only with considerable effort – e.g., with an additional transducer. The device is suitable, for example, for use in substations in the railway sector. Safety-critical surge events such as short circuits can be detected with little effort and evaluated by subsequent systems, which increases safety and allows condition-based maintenance of protection equipment.