Automatic capacitor bank MSC series

high-voltagefor power factor correctionwith detuned filters

Overview
Mechanically switched capacitors (MSC) and mechanically switched capacitors with damping network (MSCDN) are economical devices for reactive power compensation in mainly constant or predictable voltage environments. They provide voltage control, reactive power support and harmonic mitigation where filter structures or damping networks are applied.

Mechanically switched capacitors (MSC): application profile
MSCs, together with mechanically switched reactors (MSR) and filter circuits, deliver straightforward solutions for voltage regulation and grid stabilisation when fast switching is not required. They are suited to heavy-load conditions and applications prioritising simplicity and cost-effectiveness.

What are mechanically switched capacitors (MSC)?
MSC and MSCDN units are used in high-voltage transmission and substation systems for reactive power compensation and voltage stability. MSCDNs add a damping network or capacitive filter to limit harmonic amplification and improve power quality.

Role of mechanically switched capacitors

• Voltage control: Maintain voltage within operational limits under varying loads.
• Power factor correction: Improve delivery efficiency and reduce system losses.
• Grid stabilization: Mitigate sags, swells and transients to support network resilience.
• Harmonic filtering: Reduce effects of non-linear loads and inverter-based generation when filter or damping elements are used.

Key benefits
Compact, modular and cost-effective compensation with options for harmonic damping when equipped with damping networks; suitable for integration into substations and industrial sites and for continuous operation under specified conditions.

Mechanical switching variations
Different mechanical switching configurations and component types enable tuning to application requirements, including automatic bank switching for voltage regulation and manual operation for maintenance or specific operating scenarios.

Applications and grid integration

• Delivery and commissioning of MSC/MSCDN units for substation extension projects and reinforcement schemes.
• Design and engineering to ensure proper interaction with network protection, control and existing equipment.
• Provision of targeted voltage support and frequency-selective filtering at connection points to improve substation power quality.

Technical specifications

• Functions: Reactive power compensation, voltage control, harmonic mitigation (with MSCDN or filter circuits).
• Typical application: High-voltage transmission systems, substations and industrial filter installations.
• MSCDN damping principle: Capacitive filter structure that supplies capacitive reactive power at supply frequency and provides damping to absorb harmonic energy beyond tuning frequencies.
• Switching method: Mechanical switching via high-voltage circuit breakers, suitable for relatively low switching rates in predictable-voltage applications.
• Example operating range: Project-dependent; typical MSCDN banks delivered in multi-MVar to multi-10s MVar ranges for substation use.
• Design features: Modular, compact layouts for integration into constrained substation spaces.
• Performance: Improves power quality, reduces losses and supports grid stability under varying load and harmonic conditions.
• Maintenance: Regular inspection of mechanical components, verification of electrical connections and monitoring of operation to maintain performance and lifetime.
• Integration: Can complement FACTS and other grid management systems for comprehensive reactive power and harmonic management.