The smart IoT device RAM-1 is intended for remote monitoring and advanced analysis of power grids and surge arresters.

Device ISOP R - requirements

26.02.2016 12:36

The remote status indicator ISOP-R for surge arresters must fulfill the following requirements:
  • Accurately isolate and measure the resistive component of the leakage current flowing through the grounding conductor,
  • Process the information and transmit it wirelessly to control centers using a GSM modem,
  • Autonomous operation of the status indicator of metal oxide surge arresters will be provided by a panel with a solar cell and a battery,
  • Ability to define the desired activation zone,
  • Sensors time interval activity zone [0,1s… 1s],
  • Analog filter that allows the measurement of currents up to the 5th harmonic (150 Hz). Anti aliasing filter for later processing of signals on the microcontroller,
  • Possibility of powering the sensor circuit by the microcontroller (periodic wake-up),
  • Permanent detection of the status of the actuator, also in case of MO surge arrester destruction when there is not enough voltage in the super-capacitors to power the microcontroller (bistable relay),
  • Solar charger of super-capacitors,
  • Buck-boost DC / DC converter for systems power supply (stabilized voltage 3.6V),
  • Power supply filter for GSM modem,
  • The logic for power supply management and system wake-up,
  • Controlled power supply for external power supply of the sensor module (switching capacitor),
  • A voltage multiplier that generates an unstabilized 7.2V output voltage,
  • Interface for activating the bistable relay with the trigger signal of the sensor,
  • Bistable relay driver,
  • Management driver for sensor with current amplification,
  • Adaptive circuits for voltage measurement with A/D converters,
  • Connectors for connection to the process module,
  • ESD overvoltage protection.
The circuit is implemented on an integrated board with SMD technology. The circuit does not need an external power supply because it uses its own power supply to trigger the indicator.