DEIF MVR-200 Medium Voltage Relay: Installation and Wiring Engineering Guide

DEIF MVR-200 Medium Voltage Relay: Installation and Wiring Engineering Guide

Introduction: A New Generation Universal Platform for Medium Voltage Protection

The protection reliability of medium voltage (MV) switchgear and rotating equipment is directly related to personnel safety and production continuity in industrial distribution, ship power systems, and renewable energy power stations. Traditional discrete protection relays have a single function and are difficult to adapt to increasingly complex system requirements; Modern intelligent electronic devices (IEDs) not only need to provide complete protection functions, but also require flexible hardware expansion capabilities, fast response speed, and adaptability to harsh environments.

The DEIF MVR-200 series medium voltage relay is a universal protection platform that emerged in this context. It covers various application scenarios such as feeders, motors, generators, transformers, and voltage protection. With a modular hardware architecture, rich communication interfaces, and powerful expansion capabilities, it provides highly flexible protection solutions for system integrators and cabinet manufacturers. This article will systematically analyze the hardware modules, installation specifications, wiring points, and typical applications of MVR-200 based on the official installation manual, providing comprehensive technical references for engineers engaged in the design and implementation of medium voltage protection systems.

Product Series and Model System: Accurately Matching Application Requirements

The MVR-200 series adopts a clear naming convention for product models, allowing engineers to quickly select the correct model based on the application scenario.

Typical functions of model prefix application scenarios

MVR-F2xx feeder protection (Feeder) overcurrent, ground fault CBFP、 Automatic Recloser

MVR-M2xx motor protection (Motor) overload, locked rotor, differential, start monitoring, thermal protection

MVR-G2xx Generator Protection: Differential, Reverse Power, Over/Under Frequency, Stator Grounding

MVR-T2xx Transformer Protection: Differential, Overcurrent, Grounding, Temperature Monitoring

MVR-V2xx Voltage Protection: Over/Under Voltage, Frequency, Vector Jumping ROCOF

The main hardware differences among various models are reflected in the configuration of the measurement module:

F201/M210/V211 and other 21x series: 1/4 19 inch rack width, suitable for compact switchgear.

F255/G257/T257 and other 25x series: 1/2 19 inch rack width, supporting more analog and I/O expansion.

Deep Analysis of Hardware Modules: Building an Scalable Protection Platform

The MVR-200 adopts a modular slot design, and users can choose different functional modules according to their application needs. All modules are installed in standard chassis and support 19 inch rack mounting or panel opening mounting.

1. CPU, I/O, and power module (core module)

This is the basic module of every MVR-200 device, integrating the processor, communication interface, basic I/O, and power supply.

Processor and Memory: Based on high-performance microprocessors, all binary inputs are sampled with a 5ms scan cycle to ensure fast response to protection signals. The control of the output relay is also completed within a 5ms cycle, and the theoretical delay from input detection to output action is about 0-15ms (excluding the mechanical action time of the relay).

Communication interface:

COM A (RJ-45): Used to connect MVR debugging software (Utility Software) and station control layer protocols such as IEC 61850, Modbus TCP, DNP3 TCP, etc.

COM B (RS-485): Used for serial SCADA communication such as Modbus RTU, DNP3, IEC 103, etc., supporting multi-point bus topology.

Digital input:

MVR-21x provides 2 or 3 digital inputs, while MVR-25x provides 3. The rated threshold voltage can be selected from 24V, 110V, or 220V DC to adapt to different levels of switch signals.

Each digital input supports software configurable features such as activation delay, drop off time, polarity selection (NO/NC), and AC mode (used for anti jitter processing of AC input signals).

Digital output:

5 output relays, including 4 normally open (NO) contacts and 1 conversion (CO) contact. Rated voltage 250V AC/DC.

System Fault Relay: a switching contact that closes (16-18) when the equipment is powered on normally and there is no system fault, and closes (16-17) when the equipment loses power or an internal fault is detected, used to achieve "fault safety" monitoring.

Power Supply:

Optional H-type (100~125V DC) or L-type (24/48V DC) to meet the requirements of different DC power supply systems.

The power supply has a power-off holding time of>150ms, a maximum power consumption of 15W, and a startup time of<5ms.

2. Current measurement module (CT module)

This module provides 5-channel current measurement inputs, which are the basis for most feeder, motor, and generator protections.

Channel allocation: 3 phase current inputs (L1/L2/L3)+1 rough residual current (I01)+1 fine residual current (I02).

Rated value and accuracy: The rated secondary current is 5A (adjustable by software within the range of 1-10A), with an accuracy of ± 0.2% within the range of 0.05 × In~4 × In.