Measurements for the energy system
The laboratory develops and applies systems for the study and the characterisation of voltage and current sensors for the measurement of energy, power and power quality in the modern electrical energy distribution grids.
It is equipped with systems for generation and measurements of distorted voltage waveforms up to 30 kV with harmonic content up to 20 kHz, which allows the sensor study of sensors in presence of actual conditions, such as those occurring in the presence of distributed generation. The measurement method is based on the comparison with a reference resistive-capacitive divider or a two-step produce that involves the use of two HV capacitors and a digital current comparator.
The alternating current generation capabilities range from the milliampere up to 10 kA, whereas distorted waveforms are obtained by superimposing to the fundamental tone currents e up to 100 A in the frequency range up to 100 kHz.
The laboratory designs and develops advanced sensors for the determination of the thermodynamical properties of fluids in liquid phase (for example, compressed refrigerant gases, fuels, bio-fuels and more ...).
The laboratory equipment includes pycnometers for the measurement of the fluid density in the temperature range (- 40 e 120) °C and for pressure up to 400 MPa, and vibrating tube densimeters working in the same temperature range for pressure up to 70 MPa, with measurement uncertainties within 0.1 %.
As to measurement of the speed of sound, ultrasound sensors are used, which operate in the temperature range -173 °C to 100 °C at pressure up to 400 MPa. Specific sensors have been developed, for the characterisation of fluids that, in the liquid phase, show speed of sound lower than 1000 m/s, with uncertainties of 0.05 %.
The specific heat capacity is measured by two differential scanning calorimeters (DSC) working from -90 °C e 550 °C at pressure up to 7 MPa. The laboratory is also equipped with a modulated adiabatic calorimeter (mAC) for the characterisation of reference materials. The measurement uncertainty is within 2 % for the DSC e les than 0.5 % for the mAC.
Viscosity is measured with a Ubbelohde type viscometer from -40 to 120 °C with uncertainty of the order of 1 %.
The laboratory designs and realises systems for the characterization of magneto-elastic devices under dynamic conditions. Also, energy harvesting systems are realised and investigated.
The laboratory is equipped with a 10 kN (7 kN rms) and torque ± 100 Nm linear-torsion test machine. The machine can perform tests with a mechanical excitation frequency of up to 100 Hz. It is coupled to a magnetizer and a system for the measurement of magnetic and magneto-mechanical hysteresis cycles. Tests are carried out at controlled ambient temperature of 23 ± 0.5 ° C. Normally, it operates on a cylindrical specimens of 12 mm in diameter and 60 mm in height. In the laboratory there is also a test system for the characterization of vibrational harvesters, equipped with a piezoelectric excitation system up to 2.5 kN (including preload) and a laser velocimeter.