Voltage and Current Measurement in DC Traction Power Supply Substations
Railway | DC Substations
Sector
Short-circuit detection, wear monitoring for predictive maintenance
Application
750 to 3000 V DC, isolation of up to 3600 V AC/DC, continuous isolation Test Voltage of up to 15 kV AC
Measured Parameter/Signal converted/isolated
High-voltage transducers that measure quickly and precisely while withstanding high loads
Key Requirements
The Reliable Market Leader: The P40000 Product Series
For the reliable and precise measurement of voltage and current in DC substations, Knick has been supplying galvanically isolated measuring transducers for decades. During this time, we have become the global market leader in this field. Therefore, Knick is also the first contact for suppliers and operators of DC substation technology when special technical challenges need to be mastered, e.g. possibilities of wear monitoring for predictive maintenance.
Substations for DC power supply have rated powers as high as the upper single-digit MW range. Substations and the grid sections they supply must be effectively safeguarded against short circuits. The protection mechanism must reliably interrupt high levels of current as quickly as possible, limiting the power that flows into the short circuit.
The protective device must measure current and voltage in order to execute algorithms for short-circuit detection. This requires high voltage transducers that measure quickly and precisely while withstanding high loads. They must master voltages between 750 and 3000 V DC, including temporary surges in the case of energy recovery for braking trains, for example.
The universal high-voltage transducers P41000 and P42000 have proven their value in DC traction power supply substations worldwide.
Recommeded Products for Measurements in DC Substations
P41000 – Current Measurement via Shunt
The universal high-voltage isolation transducer P41000 comes in a compact modular housing. It converts voltages into standard signals in shunt applications. The high-voltage transducer P41000 provides high measurement accuracy without long-term drift.
P41000 AG – Current and Overcurrent Measurement
Two-in-one: Adaptive gain for nominal current and overcurrent measuring. High accuracy in the nominal current range, sufficient accuracy for up to 11 times of nominal current, 3600 V isolation, 15000 V test voltage. The high-voltage signal conditioner P41000 AG is the first of its kind on the market.
P42000 – Voltage Measurement
The P42000 is a universal high-voltage transducer for direct measurement of high voltages, like bipolar measurement of DC power-supply in switchgear panels and frame fault detection.
P44000 – Temperature Measurement
The P44000 temperature transmitter allows for measurements of up to 300 °C via Pt100 resistance thermometer. Low measurement error of typically 0.5 K and short T90 delay time of 100 ms up to 6600 V AC/DC continuous isolation.