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Multilin D90Plus

Line Distance Protection System

The D90Plus is a sub-cycle line distance protection system and bay controller suitable for protecting transmission lines and cables including lines equipped with series compensation. The D90Plus supports dual-breaker applications and can be used for single or three-pole tripping. The D90Plus supports different teleprotection schemes, including DCB, DCU, POTT, Hybrid POTT, and PUTT. The D90Plus also provides synchrophasor measurement over Ethernet per IEEE C37.118.

Key Benefits:


  • Secure sub-cycle distance protection

  • CCVT filter improves performance without intentional delays or reduced fault coverage

  • Superior phase selection algorithm ensures secure high-speed single-pole tripping

  • Reliable and secure protection on lines equipped with series compensation

  • Color HMI with metering, event records and control

  • Fault and disturbance recording at up to 128 samples/cycle

  • Built-in phasor measurement unit streaming synchrophasors as per IEEE C7.118

  • Configurable alarm annunciator eliminates the need for separate annunciator panel


Applications :


  • Overhead lines including series-compensated lines and underground cables

  • Backup protection for generators, transformers and reactor

  • Single and dual-breaker circuits requiring single/three-pole autoreclosing and independent synchrocheck supervision

  • Circuits with in-zone power transformers - secure application with Capacitively-Coupled Voltage Transformers (CCVTs)


Protection and Control

Key Features:

  • Secure time-domain algorithm providing sub-cycle distance protection

  • Phase distance with independent compensation settings for in-zone power transformers

  • Ground distance with independent self and mutual zero-sequence compensation

  • Out-of-step tripping and power swing blocking

  • Directional overcurrent: phase, neutral and negative sequence

  • Wattmetric zero-sequence directional power

  • Under/over frequency

  • Synchronism check for dual-breaker applications

  • Single/three-pole four-shot dual-breaker autorecloser

  • Customization of protection and control functions with independent protection FlexLogic™, FlexCurves™, and FlexElements™

  • Advanced automation controller with independent automation programmable logic

  • Bay control through front panel HMI

Modern power systems are under increasing constraints in their ability to transmit power from generation facilities to major load centers, and are forced to operate closer to their natural stability limits. Under these conditions, the critical clearing angle – and corresponding critical clearing time –

become progressively smaller and there is an increasing need to minimize the fault clearing time on

 these constrained circuits.

The D90Plus is ideally suited for application on circuits where fast fault detection and small breaker failure margin are required. The D90Plus allows transmission limits to be maintained or even increased while respecting the transient stability limits of the power system.

Monitoring and Metering

Key Features :

  • Continuous monitoring of AC input channels

  • Metering - current, voltage, frequency, power, energy and synchrophasors as per IEEE C37.118

  • Transient recorder - 128 samples/cycle, 1 minute or more of storage capacity

  • Disturbance recorder – 1 sample/cycle, 5 minutes or more of storage capacity

  • Event recorder - 8000 time tagged events, with 0.5 ms scan of digital inputs

  • Comprehensive display of metering, phasors, maintenance and fault information via the front panel


Monitoring and Metering

The D90Plus includes detailed metering and recording for all AC signals. Voltage, current, and power metering are built into the relay as a standard feature. Current and voltage parameters are available as total RMS magnitude, and as fundamental frequency magnitude and angle.

Advance Automation

The D90Plus incorporates advanced automation features including powerful FlexLogic™ (user programmable logic) independent for protection and automation schemes. Combined with the communication capabilities, the D90Plus provides an advanced, highly flexible platform for substation automation applications. The D90Plus integrates seamlessly with other relays for distributed applications like interlocking and special protection schemes.


Key Features :

  • Multiple protocols - IEC 61850, DNP 3.0 Level 2, Modbus RTU, Modbus TCP/IP, IEC 60870-5-104

  • Up to three independent IP addresses

  • Increase network availability by reducing failover time to zero through IEC62439-3 "PRP" support

  • Front USB port for high-speed communications

Advance Communications

The D90Plus provides for secure remote data and engineering access, making it easy and flexible to use and integrate into new and existing infrastructures. Fiber optic Ethernet provides high-bandwidth communications allowing for low-latency controls and high-speed file transfers of relay fault and event record information. The availability of three independently configurable Ethernet options provides the means to create fault tolerant communication architectures in an easy, cost-effective manner. The D90Plus supports the most popular industry standard protocols enabling easy, direct integration into SCADA systems.

  • IEC 61850

  • DNP 3.0

  • Ethernet Global Data (EGD)

  • IEC 60870-5-104

  • Modbus RTU, Modbus TCP/IP

  • PRP as per IEC 62439-3

Software and Security

EnerVista™ Software

The EnerVista™ suite is an industry-leading set of software programs that simplifies every aspect of using the D90Plus relay. The EnerVista™ suite provides all the tools to monitor the status of the protected asset, maintain the relay, and integrate information measured by the D90Plus into DCS or SCADA monitoring systems. Convenient COMTRADE and Sequence of Events viewers are an integral part of the UR setup software included with every UR relay, to carry out postmortem event analysis and ensure proper protection system operation. Learn More

Access Control
Multilin devices and relays are designed with simple but powerful security to enable reliability and compliance for virtually any project or implementation. With support for multi-level permissions and multi-factor supervisory controls, Multilin devices can help you manage the integrity of your system during commissioning, testing, implementation, and beyond. The UR and URPlus families provide separate authentication for settings and commands to the system. In addition, as discrete authentications for local and remote access, they also provide a supervisory control factor that can lock or unlock a device for configuration changes and other modifications.

Intrusion Detection
Multilin’s family of protection and control products can also help enable your security perimeter and intrusion detection programs. By providing essential alarming and logging of critical events, Multilin devices can help you detect potential breaches within your system and allow you to respond quickly and effectively. Specifically, unsuccessful access attempts are logged, alarmed, and lead to potential attackers being locked out. This ensures the reliability of your system during questionable activity, and a control factor that can lock or unlock a device for configuration changes and other modifications.


Auditing and Reporting
With the security audit trail reporting feature and support for event logging of key activities such as configuration changes, Multilin devices can help ensure device and protection system integrity, and perform forensic auditing of activities and changes 
for compliance.

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Digital fault recorder summary with the latest information on the events, faults, transients and disturbances.

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Control screen for the pre-configured bay with breaker & disconnect control in multiple pages using dedicated push buttons on the front panel.

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Front Panel

D90Plus Brochure

D90Plus Manual

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