Multi Stage

The high voltage equipment MVCells are high technology equipments usable to compensate the reactive power of power grids. They are essential to improve the performance, saving energy. The multi stage is typically used to compensate an electric system, with many loads.

Description

The high voltage equipment MVCells are high technology equipments usable to compensate the reactive power of power grids. They are essential to improve the performance, saving energy. The multi stage is typically used to compensate an electric system, with many loads.

The first stage can be composed of:

  • cable entry
  • switch isolator
  • switch isolator with earthing blades
  • mechanical safety interlock
  • measuring transformers
  • surge protection devices (SPD)
  • Control board

All the other stages are compensation stages customized to your needs. Each compensation stage is composed of:

  • Protection with HRC fuse
  • switching device (contactor or circuit breaker)
  • Series inductance (damping or de-tuning)
  • Capacitor bank
  • Other accessories available on request

The rated voltage of each stage can be up to 24 kV, the rated power up to 4 MVAr. Higher powers can be achieved by paralleling stages.

The equipments are customizable in terms of:

  • Rated power and voltage
  • Protection degree from IP00 till IP55
  • Lightning withstand (BIL – Basic Insulation Level)
  • Short circuit withstand: up to Icw = 50 KA @ 3s
  • Safety levels for the operator
  • Harmonic levels on the electric grid

Diagnostic levels:

o   low

  • undervoltage and overvoltage ANSI 27/59
  • Over temperature in the cabinet
  • Under compensation
  • Harmonic level THDi too high

o   medium

  • capacitor bank unbalance with a voltage sensor on the neutral (Neutral Voltage Sensor, NVS) in a single star (Y) configuration – ANSI 59N
  • Capacitor bank unbalance with a current sensor between the neutral point in a double star (YY) configuration (Neutral Current Sensor, NCS) – ANSI 46N
  • Fuse failure indication

o   high

  • Overload ANSI 49RMS
  • Overcurrents ANSI 50/51
  • Capacitor bank unbalance with a voltage sensor between the neutral point in a double star (YY) – Neutral to neutral sensing
  • overpressure drives capacitive
  • fire detector protection
  • Indoor or outdoor installation
  • Altitude up to 4500 m above see level