⚡ Grid

Grid HVDC/MVDC Transmission


As grid infrastructure modernizes to meet the demands of electrification, data centers, EV fast charging, and distributed energy integration, traditional AC systems face limitations in efficiency, control, and capacity. High Voltage Direct Current (HVDC) and Medium Voltage Direct Current (MVDC) systems are increasingly adopted to enhance power flow control, reduce transmission losses, enable long-distance and subsea transmission, and support DC-native loads and DERs.

Why DC?

In the near future, DC-native campuses that cCombine solar, storage, EV charging, and DC building loads will become commonplace.

  • Lower Losses: DC eliminates reactive power and reduces I²R losses in long-distance and high-capacity transmission.

  • Efficient Integration

    : Suited for renewables (solar PV), BESS, and EV charging—all of which are DC-native.
  • Smaller Footprint: DC cables and equipment often have a smaller physical and electromagnetic footprint.
  • Advanced Control: Fast and precise power flow control using power electronics.
  • Grid Resilience: Supports grid segmentation, islanding, and black start capabilities.

HVDC Use Cases

HVDC is ideal for large-scale, long-distance, and high-capacity power applications. Key deployments include:

  • Bulk Power Transfer: Efficiently moves large quantities of electricity across hundreds or thousands of kilometers with minimal losses.
  • Offshore Wind Integration: Transmits power from remote wind farms to shore without the losses and synchronization issues of AC.
  • Grid Interconnections: Links asynchronous AC grids (e.g., different frequency regions or countries) without requiring frequency matching.
  • Urban/Subsea Corridors: Enables underground or underwater transmission with minimal footprint and visual impact.
  • Data Centers & Energy Hubs: Powers energy-intensive clusters where high reliability and efficiency are critical.

MVDC Use Cases

MVDC systems operate typically in the 1–35 kV range and are ideal for localized or facility-level energy distribution. Emerging applications include:

  • EV Charging Infrastructure: Delivers medium-voltage DC directly to ultra-fast chargers, bypassing unnecessary AC/DC conversions.
    • >Microgrids: Ideal for military bases, campuses, and industrial parks where loads, DERs, and storage are DC-based or require high power quality.
  • Data Centers & Fabs: Supports low-loss, reliable, and redundant power delivery inside facilities with mission-critical loads.
  • Marine, Aviation, and Rail: Used in ships, aircraft, and trains to reduce weight and improve efficiency in onboard power systems.

Technology Stack

  • Rectifiers & Inverters: Convert AC?DC (line-commutated or VSC-based).
  • DC/DC Converters: Voltage level management, isolation, and control.
  • DC Switchgear & Breakers: Protection and segmentation (mechanical or solid-state).
  • Cables & Busways: Insulated for DC transmission; underground or subsea.
  • Control Systems: Real-time power flow, fault isolation, and dispatch.

Standards & Codes

  • IEC 61850-90-14: Communication for DC systems.
  • CIGRÉ TB 496: Protection of DC grids.
  • IEEE 2030.10: Standard for DC microgrids.
  • UL 1741 SB: Inverter grid interoperability (includes DC interaction).
  • NFPA 70 (NEC): Covers wiring methods for DC (Articles 690, 706).

Topologies & Architectures

  • Point-to-point HVD: Simplest and most common; two-terminal DC link.
  • Multi-terminal HVDC: Multiple endpoints, enabling DC meshed grids (emerging).
  • MVDC Ring/Loop: Used in microgrids and isolated systems.
  • Bipolar/Monopolar: Configurations for redundancy and fault tolerance.

Cybersecurity and Utility Interfacing

As microgrids become more connected and critical, cybersecurity and utility compliance are essential. Key considerations include:

  • Grid Interconnection Standards
    Must meet IEEE 1547, UL 1741 SB, and local utility specs. Requires coordination with utility SCADA and protection systems.
  • Cybersecurity Requirements
    NERC CIP, IEC 62443, and NFPA 70B are applicable depending on facility type. Must protect against intrusion, spoofing, and ransomware.
  • Air-Gapped Backup Controls
    Especially relevant for defense, hospitals, and disaster recovery sites.

AI and Automation

Emerging AI tools are being integrated into the control layer for predictive and adaptive energy management. Applications include:

  • Solar and load forecasting using machine learning.
  • Predictive maintenance and fault detection.
  • Optimized battery cycling for cost and longevity.
  • Distributed agent-based negotiation between DERs.
  • Digital twins are used to include the microgrid as a subsystem for a facility as a whole. Microgrids used for just a microgrid are not that common.

Integration Best Practices

Before deployment, ensure your control layer is fully integrated and validated across systems.

  • All DERs are visible and controllable by the EMS.
  • Islanding and reconnection have been tested with utility.
  • HMI/SCADA is accessible and usable by facility staff.
  • Communications are secure and redundant.
  • Black-start capability is confirmed and rehearsed.




Software Solutions