Marine frequency drive systems based on the Triol AT24 and Triol AT27

Obviously, only a VFD used to control the drive mechanisms of the ship is not possible. Often, the developer or manufacturer has to deal with the need to supply equipment from different manufacturers, which can lead to difficulties in the interaction of the various components of the mechanism's electrical system.

We offer complete solutions, for example, drive kits with our own step-down transformers, perfectly adapted to the needs of a particular site. In our transformers, we use UNICORE technology, which reduces the motor idling current by three times, compared to the step-lap technology used by most transformer manufacturers.

Another useful option is that we complete our orders with the local control panel, which is placed in the direct proximity of the engine and is designed according to the individual needs of the staff for easy monitoring of the system and ensuring a quick response in emergency situations.

Transformer cabinet 10/0.69KV, capacity 1000 KVA                                      Local control panel

You do not need to search for and select additional equipment to ensure the operation of complex systems. We will do it for you. For each project we create a detailed technical proposal with a description of the necessary solutions for the developer and manufacturer.

The impact of waves on a vessel, the bumps and swings, are transmitted through the VFD enclosure to its components. Vibrations from drive mechanisms and generators can cause significant damage to individual VFD elements and the vessel's mechanism. To eliminate negative mechanical impacts, Triol Corporation has created a set of measures. Among the main ones are the following: 

• The use of vibration mounts; 

• The compounding of electrical installation elements; 

• The use of anaerobic locking devices for threaded connections.

The Triol VFD is carefully tested for resistance to mechanical impacts under shipboard operating conditions. 

The certified Triol VFD is resistant to the typical mechanical impacts of marine applications: 

• Vibrations in the frequency range from 2 to 80 Hz; 

• Simultaneous static inclinations: rolls up to 15°, trims up to 5°; 

• Simultaneous rocking: onboard ±22.5°, keel ±7.5°; and  

• Short-term dynamic loads applied to the fastening points with acceleration amplitude up to 5g.

Triol Corporation struggles to maximize power density per unit volume and weight while maintaining high performance, the convenience of servicing, and maintainability.

The installation of Triol equipment in limited environments on ships and vessels is the optimal solution due to its small footprint and single-sided service.

The Triol AT24 and Triol AT27 VFDs have small dimensions, often the smallest in the world, and due to the IP55 and IP66 enclosure they can be installed almost anywhere (near the engine, pump, in the bilge, in the compartment) in conditions of high humidity or dust.

The photo shows the 800 kW AT24 VFD, which has a small size of 1300*700 mm and a 2000 mm height.

The use of liquid-cooled VFDs makes it possible to install them in rooms without ventilation or air treatment systems.

Salt air naturally corrodes the metal parts of equipment. Although most electrical equipment is installed in bilges, outside the open access of sea water, the effects of salts in the air and even more, the salt fog, are not much less than in open areas and decks.

To eliminate such environmental influences on frequency drives, the marine applications Triol AT24 and Triol AT27 Triol Corporation follows these rules:

• Enclosure elements are made using high quality stainless steel;

• All electronics and operating units are coated with a certified protective varnish in two layers;

• Cooling radiators always have a protective anodized coating; 

• VFDs always contain elements of anti-condensation heating; 

• The frequency drive packaging is designed to prevent seawater from entering the inside, during storage or installation preparation.

On the open sea, electricity for the needs of the machinery and equipment is generated by fuel generators. Typically, the shipboard mains cannot be compared to the stationary stable mains, and the power surges often exceed the usual tolerances on onshore applications. The power section of the Triol AT24 and Triol AT27 is intended for operation from the ship's mains with an isolated neutral point. The VFD maintains stable operation during long mains deviations from -15% to +10% and from -20% to +20% within 2.5 seconds.

It should be taken into account that VFDs have some disadvantages in addition to all the advantages in terms of energy savings and the implementation of the required technological processes. They generate spurious harmonic distortions into the ship's onboard mains. If this process is not controlled, harmonics can negatively affect the performance and functionality of generators and other equipment.

A number of optional and required features are provided in the AT24 VFD. Depending on the requirements of a particular project, we implement one of these solutions:

• The availability of EMC and sin-phase filters;

• A 12-pulse rectifier circuit;

• Passive input harmonic filters

• du/dt or sine filter on the VFD output for motor protection.

The AT24 VFD with an active rectifier operates in the ship's mains at THDi=2%.

Water entry into the VFD is dangerous because of corrosion. In addition, for electrical equipment, water is a factor that can cause a failure or short circuit inside the frequency drive. The same is true for dust. It is not uncommon for powerful VFDs to be installed in the hold, and after that, welding work on the ship's hull can be done. Dust and dirt are generated in the course of this work. In order to prevent humidity and dust from entering the VFD, ensure that it is properly enclosed with the required degree of protection. 

The Triol AT24 and Triol AT27 have a wide range of enclosure types, depending on the proposed conditions: for clean and dry rooms - the IP21, for most electrical rooms - the IP54 or IP55, for the most challenging conditions - and the IP66 with air or liquid cooling. 

An additional advantage of the Triol AT24 and Triol AT27 is the possibility to customize the frequency drive enclosure to suit specific connection locations. In the current conditions, when the supply of electronic components is changing dynamically, we are forced to change our technical solutions in order to provide the claimed technical and price characteristics, quality level and reliability.

With these changes, we keep the agreed dimensions and connection points, which allows the engineer and shipbuilder to guarantee a multi-year supply of the equipment agreed in the project, with no need to change anything in the project.

Among the important requirements for products for shipbuilding are dependability, reliability, a high average equipment lifetime and exceptional overall lifetime for the equipment. These values should be higher than those for onshore frequency drives, general industrial and for VFDs in the mining industry. 

Due to high-quality components, high-level technical developments, as well as accumulated knowledge and experience, we can guarantee in the Triol AT24 and Triol AT27:

• An average service life before factory repair of not less than 160 thousand hours. 

• An average service life before factory repair of not less than 20 years. 

• An average total lifetime of enclosure parts of not less than 40 years.

A high mean time between failures (MTBF) will allow you to reduce downtime and service, as well as reduce the VFD ownership costs. For example, most manufacturers use electrolytic capacitors with a lifetime of 3-4 years in their frequency drives. This leads to their periodic replacement during the life cycle. During the lifetime of the VFD, one will have to make at least 4 replacements, and this will cost as much as another similar VFD. The Triol AT24 and Triol AT27 frequency drives use polypropylene capacitors, which ensures that the product operates without overhaul during its entire lifetime. Therefore, you can be sure of the quality and durability of the mechanisms, without the risk of unexpected repairs or component replacement.

The modular construction of the Triol AT24 and Triol AT27 frequency drives allows for the reservation and rapid restoration of operation in emergency situations by replacing individual power cells. Roll-out cells inside the VFD allow one to dramatically reduce the time for replacing a failed unit with a few maintenance staff. This solution allows the fastest and quickest response to emergency situations and performs the necessary technical and repair operations. Power cell unification reduces the list of items in the spares supported on the ship.

The block design of the panels allows you to simplify the process of replacing the electronics units when they fail, as the availability of spare parts can further reduce the time to restore the VFD's performance. 

The information system for diagnosing the condition of the VFD allows you to localize the problematic part (e.g., power cell, electronics unit, mains or motor faults, etc.) in the shortest time. All prompts are in the text warnings form and do not require additional reference to the documentation. 

The most challenging project in an exciting industry to implement will be the next challenge on the road to perfecting the best low-voltage variable frequency drives on the market. We look forward to helping you realize your most ambitious plans and projects!