DEIF DM-4 Marine&Offshore Ship Power Management System

DEIF DM-4 Marine&Offshore Ship Power Management System

In the fields of ship electric propulsion, offshore platforms, and complex marine equipment, the reliability, flexibility, and maintainability of the power system are directly related to operational safety and efficiency. The Delomatic 4 DM-4 Marine&Offshore system (hereinafter referred to as DM-4) launched by DEIF is a distributed power management platform designed specifically for harsh marine environments. It inherits DEIF's more than 20 years of experience in ship generator control and deeply optimizes for complex working conditions such as DP 2/3 power positioning, multi busbar segmentation, and shaft generator/motor switching. This article is based on the DM-4 data manual and systematically elaborates on its system architecture, core modules, protection functions, communication networking, and engineering application points, providing comprehensive technical references for ship electrical engineers and system integrators.

System positioning and applicable scenarios

DM-4 is a highly flexible power management system suitable for complex ships and offshore power stations that include diesel engines, gas turbines, and shaft generators. Its typical applications include:

Diesel electric propulsion (including DP 2 and DP 3 grades)

Supply vessel (equipped with 2 shaft mounted generators and 2 or more diesel generators)

Shaft driven generator doubles as an electric motor (reversible operation)

Multi bus system (including bus tie circuit breaker control)

Offshore platforms and drilling platforms (including gas turbines)

Shore power connection management

The system supports integrated control of up to 15 generator sets and can also manage bus tie circuit breakers and shore power circuit breakers. Each DGU (DEIF Generator Unit) is equipped with a high-precision three-phase measurement circuit, and all electrical parameters and alarm information are displayed through an LCD display unit. The system comes standard with an AOP-1 additional control panel (for the main DGU) and can be connected to up to 5 AOP-2 remote control panels via CANbus, with a maximum distance of 200m, enabling dual control both locally and in the control room.

Hardware modular design

The most prominent feature of the DM-4 system is that it only requires four hardware modules to build a complete system, greatly simplifying spare parts inventory and maintenance complexity:

1. PCM 4-1/PCM 4-5 (8TE wide)

The system core module integrates power supply, main CPU, and I/O router.

PCM 4-1 (spare/replacement): Provides 3-channel CAN, 1-channel RS485, DM-4 LAN, and USB service ports.

PCM 4-5 (standard): Provides 2 CAN channels, 2 RS485 channels (with one channel up to 115 kbps), 1 Ethernet channel (supporting Modbus TCP/IP and USW connections), DM-4 LAN and USB ports.

Both support 24V DC power supply (-25%/+30%), maximum current of 6A, and have battery voltage measurement function (accuracy ± 0.8V).

2. IOM 4-1 (6TE wide)

Universal I/O module, including:

16 input channels: can be independently configured as current input (0-20mA), voltage input (0-10V), or binary input (dry contact) through jumper wires. Support active zero point (such as 4~20mA, 2~10V), precision 10 bit resolution, impedance: mA input 50 Ω, V input 15k Ω. Binary input ON detection maximum resistance 100 Ω, optional cable monitoring (requires external 270 Ω resistor).

12 relay outputs: programmable as normally open or normally closed (closed/open), with contacts rated at 250V AC/24V DC, 8A. All outputs will automatically disconnect when power is lost.

2 analog outputs: 0~20mA (offset of 4~20mA), maximum load of 500 Ω, accuracy Class 0.5, 10 bit resolution, and isolated from other circuits in the system (500V AC, 1min). When power is lost, the output returns to zero.

3. SCM 4-1 (6TE wide)

Multi functional transmitter module, integrated with:

High precision three-phase electrical measurement (Class 0.5, compliant with IEC 688)

Integrated synchronizer and circuit breaker control

Suitable for generator or busbar applications

4. SCM 4-2 (12TE wide)

Added on the basis of SCM 4-1:

Governor (GOV) and Voltage Regulator (AVR) Control Board (Supports Binary or Analog Output)

Suitable for generator control that requires direct drive speed regulation/excitation

Each DGU can install up to 4 synchronization modules (SCM 4-1/4-2), which can control 1 generator circuit breaker (GB), 2 bus tie circuit breakers (TB), and 1 shore power circuit breaker (SC), achieving a compact configuration. But each DGU only controls 1 GB, which is based on the requirements of the classification society and the design conventions of the switchgear section.

Rack size: Available in four standard racks: 24, 30, 42, and 60TE, selected based on the number of I/O and synchronization modules. For example, a 30TE rack can accommodate 3 I/O slots, 42TE has 5 slots, and 60TE has 8 slots.

Display and operation panel

Display Unit (DU): Independently installed, connected to DGU through display cables, each DGU can connect up to 3 DUs to achieve multi location monitoring. DU size 115 × 220 × 20mm, see manual for panel openings.

Additional operation panel (AOP-1/AOP-2):

AOP-1: Standard main DGU with 0.5m cable, including 8 buttons and 16 LEDs.

AOP-2: Connected via CANbus, up to 200m away, each DU can connect up to 5 AOP-2.

AOP provides system status indication and power station mode control (such as semi-automatic, automatic, manual, shutdown, etc.).

DM-4 LAN communication network

The communication between internal DGUs adopts DM-4 LAN for system computation, load distribution, and coordinated control.

PCM 4-1 uses a single twisted pair network.

PCM 4-5 can choose dual redundant LAN (to be ordered) to improve fault tolerance.

Long distance applications can be extended through fiber optic converters.

External communication: Supports RS485 Modbus RTU, Modbus TCP/IP (via PCM 4-5 Ethernet), and CANopen (via CAN interface) for easy access to SCADA or alarm monitoring systems.

Power Management

All DGUs run the same software and recognize their respective roles through the Node Switch on PCM 4. x, achieving distributed management. Each DGU can independently perform specific functions, and this design allows modules to be interchangeable as spare parts, ensuring the continuous operation of critical units in emergency situations.

The power management function includes:

Load dependent start/stop: Automatically increase or decrease the operation of the unit based on the total system load.

Programmable startup priority: Start the unit in the preset order.

Load group control: managing the input and disconnection of heavy loads (such as thrusters).

Load Shedding: Automatically cut off secondary loads before overloading.

Control/monitoring of bus tie and shore power circuit breakers.

Symmetric or asymmetric active/reactive load distribution.

Speed controller controls frequency regulation and active power distribution; AVR control achieves voltage regulation and reactive power distribution.

Protection function (ANSI standard)

DM-4 provides comprehensive protection for generators, busbars, and shore power, all of which are time limited features. The following table lists the main protection functions (ANSI numbers in parentheses):

Protection function ANSI level

Speed monitoring device 15 1 step

Overexcitation 24 2 steps

Synchronization check 25 1 step

Generator undervoltage 27 1 step

Bus undervoltage 27B 2 steps

Generator overload 32 2 steps

Generator reverse power 32R in 2 steps

Demagnetization 40 2 steps

Current imbalance 46 1 step

Phase sequence voltage 47 1 step

Circuit breaker failure 50BF 1 step

Generator overcurrent 50 4 steps

Voltage dependent overcurrent 51V 1 curve

Generator overvoltage 59 2 steps

Bus overvoltage 59B 2 steps

Voltage imbalance 60 1 step

Locking (start/synchronization) 68 1 step

Generator over frequency/under frequency 81, 2 steps each

Bus over frequency/under frequency 81B 2 steps each

Electronic locking relay with 86 channels

Speed/Voltage/Frequency Control 90-

Trip relay 94-

Advanced generator protection (engine/governor/fuel failure) 95 optional

Advanced protection (optional): Through fast communication between PMS units and load distribution deviation calculation, faults such as diesel engine, governor or fuel filter blockage can be detected, and the faulty unit can be automatically disconnected before causing serious disturbance, avoiding power loss throughout the ship. Quick load shedding (optional): Based on load deviation calculation, send an immediate load shedding signal to thrusters and other equipment to prevent generator overload. Special protection functions can be customized as needed.

Customized functions and engineering processes

The flexible I/O platform and integrated electrical parameter measurement of DM-4 provide a foundation for developing customized functions, such as:

Advanced load shedding/offloading algorithm

Load allocation for fuel economy optimization

Propulsion interface and control

Custom operating mode

Order process: Due to the highly customized system, DEIF requires customers to directly contact and provide a single line diagram (including generator and circuit breaker) and control concept description. Based on this, the DEIF project engineer completes the engineering design and provides a quotation to ensure that the system perfectly matches the requirements.

8 Utility Software（USW）

Free PC tools (available for download from www.deif.com) support:

USB directly connected to PCM (or connected to PCM 4-5 via TCP/IP)

Software Download and Parameter Setting

Online monitoring of all DGU modules

Alarm monitoring and clock synchronization

Trending Record

Quick Deployment of Installation Wizard

Summary of Technical Specifications

DGU rack

Working temperature: -25~+70 ℃

Vibration level: DNV A+C (3~13.2Hz 2.0mmpp, 13.2~100Hz 0.7g; earthquake level 3~8.15Hz 15mmpp)

Protection level: IP20

Humidity: 97% RH (IEC 60068-2-30 Db)

Installation method: Base installation

EMC/CE: Complies with EN 61000-6-1/2/3/4

Material: UL94-V0 plastic, aluminum shell, steel panel

Weight: 3.2~8.3kg (depending on configuration)

PCM module

Power supply: 24V DC (-25%/+30%), maximum 6A

Battery voltage measurement accuracy: ± 0.8V (8-32V DC)

CAN: PCM 4-1 has 3 channels, PCM 4-5 has 2 channels (125~250 kbps)

RS485: PCM 4-5 Port 1 up to 38.4 kbps, Port 2 up to 115 kbps

Safety: EN 61010-1, overvoltage category III (600V AC), pollution level 2

SCM module (electrical measurement)

Voltage measurement: Direct 100~690V rms (phase to phase), can be extended through PT, overload 2 × Un for 10 seconds, external fuse maximum 2A slow melting.

Current measurement: CT secondary 1A or 5A, overload 10A continuous, 75A continuous for 10s, 300A continuous for 1s.

Frequency range: 30~70Hz

Accuracy: Class 0.5 (IEC 688)

Harmonic measurement: up to 500Hz

Isolation: 2.5kV isolation (voltage input to other circuits)

IOM module (input/output)

16 input channels (mA/V/binary optional), 10 bit resolution

12 relay output (250V AC/8A)

2 analog outputs (0-20mA, 500 Ω load, Class 0.5）

Isolation (analog output to other circuits 500V AC)

Engineering installation and maintenance tips

Rack selection: Select 24/30/42/60TE racks based on the number of I/O and SCM, with 20% expansion margin reserved.

Network redundancy: For DP 2/3 projects, PCM 4-5 should be selected and dual redundant LAN options should be ordered.

Power reliability: The PCM module power supply should be taken from an independent battery pack and equipped with appropriate fuses (up to 6A with line protection).

Grounding and Shielding: Shielded cables are required for DM-4 LAN twisted pair and CAN bus, with single end grounding and terminal resistance configured according to the actual number of nodes (specific values can be consulted with DEIF).

Software backup: After debugging, save the complete parameter files through USW for quick recovery when replacing modules.

Vibration protection: The frame is installed on a base to meet DNV vibration requirements and does not require additional vibration reduction (certified by a classification society).