A Study on Current Issues and Solutions of DC Measurement for the DC Power Grid Era 2019

A Study on Current Issues and Solutions of DC Measurement for the DC Power Grid Era 2019

On May 31, J&D held seminar for solutions of DC measurement for the DC power grid era 2019 at CoeX, Seoul, Korea.

Seminar topic was “A study on Current Issues and Solutions of DC measurement for the DC power grid era 2019.”


Necessity of DC Power Distribution

  • It is not possible to install AC power grids in mountainous areas of islands.
  • Island mountainous areas require energy independence using renewable energy, and DC microgrids are needed to operate them efficiently.
  • DC Power Quality Meter, Voltage/current sensor, and Leakage Current Sensor are essential for efficient operation, safety and quality measurement.


Characteristics of AC Power Distribution System

  • Synchronization is required because alternating current is determined by the same power source as the amplitude and phase angles.
  • AC is difficult to manage because it has the characteristics of changing sizes on a regular basis over time.

Benefits of DC Power Distribution Systems

  • In the AC system, loss occurs during the DC-> AC, AC-> DC power conversion phase between the power facility and the load.
  • DC systems increase energy efficiency by 10-15% through the minimization of power conversion.
  • Renewable energy support also increases efficiency by approximately 2-10% through DC system linkage.
  • Direct current has no frequency, so it does not affect the loss of reactive power or inductive interference of the circuit.
  • Direct current is a power source with a constant size and orientation, and is easily linked as it is judged to be the same power source in the size is the same.


Most of the power grids not only in Korea but also in the world are composed of AC (alternating current) distribution, so the demand for DC (direct current) distribution was low. However, recently, DC distribution is in the spotlight because of the advantages of easy grid connection with distributed power systems and high energy independence and low loss of short-distance transmission.

In particular, demand for DC distribution such as new and renewable power generation, electric vehicle chargers, and ESS (energy storage devices) is increasing. Accordingly, energy independence using decentralized power sources is increasing, starting with islands and mountains.

Accordingly, facilities that can measure DC power quality are needed, and the demand for sensors capable of accurate DC voltage/current measurement related to this is expected to increase worldwide.

J&D aims to grow into a world-class company by developing more accurate and stable voltage/current measuring sensors throughout the DC power grid industry.