Blog
We are MTVD
We develop energy engineering solutions for industry.
Enthusiastic about static and rotating electrical machines, our workers make the difference.
Our services
Intelligent answers for industrial electrical machines
Solutions for the repair, improvement and comprehensive maintenance of industrial electrical machines – static and rotating.
Testing transformer insulating oils
Our facilities include an industrial oils laboratory for in-house services or
external (to a wide range of national and international clients).
Service in electrical installations
We offer solutions for low, medium and high voltage electrical installations.
We design, supply and assemble medium, low and high voltage electrical installations up to 220 kV (any power).
We offer expertise, consultancy, testing and maintenance services abroad:
- Wind farms;
- Industrial PT;
- Rotary starters;
- Substations;
- Medium voltage cells;
Full availability in External Services
We provide expertise, consultancy and external technical assistance services in the repair, improvement and maintenance of electrical machinery:
- Engines;
- Generators;
- Alternators;
- Transformers;
We also offer services in:
- Shaft alignment;
- Vibration analysis;
- Dynamic balancing;
MTVD is a company that developsengineering solutions in the energy sector, combining 30 years of experience with technology in the provision ofservices for industry. Our employees are committed to developing unique and personalised projects with the client, in the constant pursuit of excellence.
Building our position in the interventions instatic and rotating electrical machines, our ambition is to create value for our stakeholders. In the sustainable and continuous search for the best option for the Client, we are focused on raising the level of quality of our services.
In our missionour workers make the difference. It is because of his experience that our clients give us their challenges. And so we consolidate an identity based on our values:
Availability – being there when the customer needs you
Ambition – always striving to do more and better, learning from successes and failures
Collaboration – creating trusting partnerships between workers and with customers
Integrity – acting responsibly and seriously.
Intelligent answers for industrial electrical machines
We offer solutions for the repair, improvement and comprehensive maintenance of industrial electrical machines – static and rotating – in particular:
– Transformers up to 40 MVA / 60 kV. We are the main repairers – leaders in rewinding – in Portugal.
– Generators and motors – DC or AC – and submersible pumps (for low and medium voltage equipment)
How do we guarantee the quality of our services?
We carry out rigorous tests on electrical machines using an AC and DC bench:
- Transformer ratio measurement
- Stiffness tests
- Testing indirect equipment protection relays
- Analysing LV installations
- Circuit breaker opening and closing simultaneity tests
- Analysis of three-phase networks up to 4000A
- Inrush tests of rotor-wound motors
- Tangent delta test
- Measurement resistancência [de isolamento]
- Short circuit detection test
- Surge test
- Test between turns (100 Hz)
- Vibration analysis
- Dynamic engine analysis
- Thermography
- Bar-to-bar test
- Polarisation index
We look for rigour and innovation in state-of-the-art production equipment:
- Balancing equipment with a capacity of up to 6 t
- Pyrolysis furnace with a capacity of 6 m3
- Dielectric oil treatment equipment
- Mechanical lathe with a capacity of 8 tonnes and a working length of 3 metres
- Automatic rotor strapping machine for AC / DC motors
- Coil manufacturing assembly line:
- Prototype of an integrated system for impregnating motors and generators (3m diameter VPI), 10t resin tank and autoclave for drying machines and filling hermetic transformers with oil
In a continuous endeavour to improve our functions, we maintain a certified Quality Management System, based on the NP EN ISO 9001 standard.
Testing transformer insulating oils
Our facilities include an industrial oils laboratory for in-house and external services (to a wide range of national and international clients).
Tests on transformer oils are carried out using suitable equipment, duly calibrated and in line with the respective standards:
Colour (ISO 2049)
Appearance (CEI 60296)
Disruptive Voltage (CEI 60156)
Acidity Index (CEI 60296)
Water Content (CEI 60814)
Interfacial Tension (ASTM D 971)
Dielectric (tan δ) at 90 °C
PCB screening (EPA SW-846 method 9079)
The test results are related to each other, as the parameters influence each other.