移动式岸上电力变电所用于灵活的泊位服务

Why Mobile Shore Power Exists

Mobility normally addresses an infrastructure-utilization problem.

A port or shipyard may have several locations where vessels require shore power, while the demand at those positions does not occur simultaneously. Installing a complete transformer or conversion package at every berth can then duplicate expensive equipment that spends much of its time idle.

One shared package can offer another architecture. The electrical equipment remains a single resource, but the resource changes operating position according to the vessel schedule.

This can be useful for:

• adjacent berths with non-simultaneous demand;
• shipyard work locations that change with docking activity;
• phased infrastructure upgrades;
• temporary service during construction or refurbishment;
• sites where permanent electrical equipment at every berth is difficult to justify.

The benefit, however, is not simply “flexibility”.

Every relocation creates another sequence of isolation, disconnection, cable recovery, movement, positioning, reconnection and verification.

That trade-off should be evaluated before the chassis is selected.

For installations that remain in one operating position, our 集装箱式岸上供电系统 page explains the fixed containerized approach in more detail.

Transportable, Mobile and Fixed Are Different Deployment Concepts

These terms are often treated as interchangeable, but they lead to different engineering decisions.

For a transportable container, lifting and structural integrity may be enough to prove that relocation is physically possible.

For a mobile shore power package, the project must also prove that relocation is repeatable, electrically controlled and operationally practical.

The wider distinction can also be reviewed under containerized vs mobile shore power systems.

Start With the Vessel Schedule Before Selecting the Mobile Equipment

The operating schedule determines whether shared mobile capacity is useful.

Consider two adjacent berths, each capable of receiving a vessel requiring 500 kVA. If the vessels normally require shore power at different times, one 500 kVA mobile package may potentially serve both positions sequentially.

But mobility does not multiply capacity.

If both vessels require 500 kVA at the same time, the problem has changed from equipment relocation to simultaneous capacity.

The project may then require:

• two independent power packages;
• a larger centralized source with multiple feeders;
• another shared distribution architecture;
• or operational restrictions on simultaneous connection.

The number of sockets along the quay should never be confused with the amount of electrical capacity available behind them.

A Real 500 kVA Two-Berth Engineering Configuration

A two-berth engineering configuration provides a useful example of how mobility changes the complete system rather than only the enclosure.

These ratings describe that particular engineering configuration. They are not universal limits or a standard SDACME mobile product specification.

The important point is the architecture:

EMSA guidance also recognizes an LV-OPS mobile architecture in which installed high-voltage infrastructure supplies a mobile low-voltage step-down berth unit.

The Mobile Package Is More Than a Transformer on Wheels

The equipment schedule for the 500 kVA configuration shows why a mobile shore power unit should be treated as an integrated electrical package.

The low-voltage outgoing section used a 630 A breaker arrangement with protection and metering.

The dry-type transformer was configured for:

• 6.6 kV to 440 V / 60 Hz; or
• 6 kV to 400 V / 50 Hz.

Cooling fans and transformer temperature monitoring were included in the configuration.

The transformer enclosure was specified as a movable weather-resistant housing, with an enclosure protection requirement of at least IP33 for that project.

These details matter because movement does not reduce the normal electrical duties imposed on the equipment.

The package still has to accommodate:

• continuous operating current;
• prospective fault current;
• transformer thermal loading;
• marine environmental exposure;
• repeated vibration;
• switching operations;
• 以及维修通道。.

Interface Design Determines Whether Mobility Is Practical

The most difficult part of repeated movement is often not moving the enclosure.

It is re-establishing every interface correctly.

Incoming Power

The unit must connect to the available shore-side source at the approved operating position.

Outgoing Vessel Supply

The low-voltage supply must reach the vessel connection arrangement without creating excessive temporary cabling or uncontrolled cable routes.

Protective Earth and Equipotential Bonding

The designed protective path has to be re-established before energization.

控制与沟通

Status, permissives, alarms and required communications must be restored at the new operating position.

Auxiliary Services

Ventilation, enclosure auxiliaries and other support functions may also depend on the operating position.

If these interfaces cannot be recreated consistently, the project may have a movable package without having a practical mobile operating system.

Real Connection Hardware Changes the Mobility Assessment

In the two-berth 500 kVA configuration, the equipment schedule did not stop at the transformer and switchgear.

The high-voltage shore-side interface included a 7.2 kV, 350 A connection arrangement.

The low-voltage side included a 0.44 kV connection box with multiple quick-connect interfaces, including 350 A and 250 A connections.

A 10 m flexible connection cable was also included together with the electric chassis.

A system that requires substantial temporary field wiring after every relocation loses much of the operating advantage that mobility was intended to provide.

Survey the Route Before Selecting the Chassis

The mechanical carrier should be one of the later decisions, not the first.

The route needs to be surveyed against the actual package.

Important inputs include:

• route width;
• turning radius;
• gradient;
• pavement or quay-surface capacity;
• wheel or axle loading;
• total package mass;
• centre of gravity;
• 排水；;
• overhead clearance;
• crane operating envelopes;
• cargo and road-traffic routes;
• stored equipment and emergency access.

The final stopping positions also need to be defined.

A mobile electrical package cannot simply be parked wherever physical space appears available.

The approved position must support stable parking, securing against unintended movement, connection reach, safe cable routing, ventilation airflow, operating access and maintenance space.

Selecting a trailer or chassis first and then trying to make the berth accept it reverses the engineering process.

Use Approved Operating Positions, Not an Undefined Movement Area

Repeated mobility becomes easier to control when the project defines specific operating positions.

For example, Position A and Position B can each have a documented set of electrical and mechanical interface conditions.

For every position, the engineering package can define:

• source voltage and frequency;
• available fault level;
• incoming connection;
• outgoing vessel connection;
• 接地装置；;
• cable route;
• communication interface;
• access requirements;
• parking and securing method;
• and permissible operating envelope.

This is more robust than assuming the mobile package can connect safely at any convenient point along the quay.

Electrical Conditions Must Be Checked at Every Approved Position

Two stopping positions can appear mechanically identical and still be electrically different.

The upstream network impedance may differ. Cable length may change. The connection interface may change. Earthing conditions may differ.

Protection coordination may therefore need to be confirmed against the actual approved source point.

This becomes particularly important when the unit can connect to more than one input configuration or provide more than one vessel supply condition.

Short-Circuit Duty Still Belongs to the Mobile-System Design

Mobility does not remove the need for fault-level verification.

The 500 kVA engineering configuration included a dedicated short-circuit calculation rather than relying only on equipment nameplate ratings.

These are project-specific calculation results, not generic mobile shore power ratings.

Their importance is methodological.

Switchgear, transformer, cables and connection equipment still need to be checked against the fault conditions associated with the approved operating positions.

Protection and Earthing Remain Part of the Complete Shore Connection System

IEC/IEEE 80005-3:2025 treats low-voltage shore connection as a complete system rather than a standalone transformer or outlet.

For its applicable LVSC range, the standard addresses shore-side connection systems, ship-to-shore interfaces, transformers, protection, control, monitoring, interlocking and power management.

That system boundary is particularly relevant to mobile arrangements.

A package can be mechanically secured and still be electrically unready.

Before energization, the project may need to confirm:

• protective-earth continuity;
• connector status;
• 断路状态；;
• valid operating mode;
• 电压和频率；;
• control permissives;
• communication availability where required.

The chassis itself should not be assumed to provide the designed protective-earth path.

Relocation Should Be Treated as a Defined Power-System State

A mobile shore power unit should not simply be driven away when the previous vessel has finished using it.

Relocation should have a defined sequence.

This does not mean the complete original commissioning programme must be repeated after every move.

The objective is to identify what changed during relocation and verify those interfaces before the next service.

What Should Be Checked After Each Move?

The post-relocation checklist should match the actual project architecture.

The required checks should be defined during engineering rather than improvised by the berth operator every time the package changes position.

The Layout Must Support Maintenance as Well as Movement

A mobile system is still an electrical plant.

Internal layout therefore needs to consider more than minimum external dimensions.

The reference 500 kVA arrangement was developed as a compact mobile package with dedicated areas for incoming equipment, transformer equipment and low-voltage outgoing equipment.

Moving the enclosure between berths does not eliminate the need to:

• access the transformer;
• operate switchgear;
• inspect cables;
• service ventilation;
• reach terminals;
• and maintain safe internal working access.

A package that can physically move but cannot be maintained efficiently can lose availability over its operating life.

Repeated Movement Creates Additional Maintenance Duties

Fixed electrical equipment mainly experiences stationary environmental and electrical stresses.

Mobile equipment adds another stress source: repeated mechanical movement.

This can affect:

• bolted connections;
• cable supports;
• terminal points;
• door hardware;
• ventilation components;
• instrument connections;
• sensors;
• plugs;
• and flexible cables.

The carrier itself also becomes part of the preventive-maintenance programme.

Depending on the movement arrangement, that can include wheels, brakes, steering, drive equipment, jacks, position sensors, securing devices and structural inspection.

Mobility Creates a Shared-Capacity Dependency

Sharing one package between several berths can reduce duplicated equipment.

It also creates a common dependency.

If the shared unit is unavailable because of transformer maintenance, switchgear fault, chassis problems, connector damage, a blocked movement route or scheduled inspection, every berth that depends on that package can lose access to the shared resource.

Transfer Time Is Part of the Capacity Study

A berth schedule does not contain only electrical load. It also contains time.

If Vessel A finishes shore power service at one berth and Vessel B requires the same mobile unit elsewhere, the practical transfer time includes:

• normal disconnection;
• 隔离；;
• cable recovery;
• movement authorization;
• travel;
• final positioning;
• securing;
• reconnection;
• verification;
• and energization preparation.

A short physical drive can therefore produce a much longer operational transfer window.

Projects with more complex simultaneous-load requirements should also evaluate the wider 多泊位岸电系统设计 rather than assuming one shared mobile package will be sufficient.

When Is Mobile Shore Power a Strong Architecture?

Mobility becomes attractive when several conditions align.

• There are multiple approved service positions.
• Their full shore power demand is largely non-simultaneous.
• A shared package can meet the required single-vessel load.
• The movement route is practical.
• The package can be positioned and secured consistently.
• Electrical interfaces can be connected repeatedly without extensive field work.
• Transfer time fits the berth operating schedule.
• Post-relocation verification can be completed predictably.
• Carrier maintenance does not create unacceptable availability risk.

When these conditions are met, mobility can reduce duplicated major equipment while preserving operational coverage.

When May Fixed or Independent Equipment Be Better?

A mobile system should not be selected simply because it sounds more flexible.

Fixed or independent equipment may be more suitable when:

• two or more berths regularly require shore power simultaneously;
• the movement route crosses critical cargo or vehicle operations;
• ground loading or turning geometry limits the carrier;
• repeated cable handling is difficult;
• repositioning requires long shutdown periods;
• electrical conditions vary substantially between locations;
• very high availability is required at every berth;
• or repeated reconnection introduces more work than equipment sharing saves.

Engineering Inputs Required Before Selecting a Mobile Architecture

A meaningful mobile shore power review should begin with project information rather than a product catalogue.

With these inputs, fixed, transportable and operationally mobile architectures can be compared on the same engineering basis.

技术参考