Laboratory work

Laboratorij za termoenergetiko

Wind energy: Operational characteristics of the wind turbine

Objectives

Operational characteristics of the wind turbine 2

Get to know the operation of the wind turbine and define the

characteristics of the wind power plant, to measure the electrical current and electrical voltage at different load of the turbine, to

calculate maximum power, critical wind speed and efficiency

Wind turbine

Operational characteristics of the wind turbine

Wind turbine

Operational characteristics of the wind turbine

The conversion of kinetic energy into electrical energy

Operational characteristics of the wind turbine

Theoretical background

Operational characteristics of the wind turbine 6

𝑊𝑚𝑎𝑥 = 𝑚 ∙𝑣02

2

Maximal kinetic energy of the wind

𝑃𝑚𝑎𝑥 = 𝜌 ∙ 𝐴1 ∙ 𝑣0 ∙𝑣02

2

Maximal power of the wind:

𝑃𝑑𝑒𝑗 = η𝑎 ∙ η𝑖 ∙ η𝑚 ∙ η𝑅 ∙ η𝐺 ∙ 𝑃𝑚𝑎𝑥

Real power of the wind

ηa … aerodynamic efficiencyηi … internal efficiencyηm … mechanical efficiencyηR …. Efficiency of multiplicatorηG … generator efficiency

Experimental rig

Operational characteristics of the wind turbine

Experimental work

Measurements:

Electrical current

Electrical voltage

Wind speed

Rotational frequency

• Calculate:

Power of the generator 𝑃 = 𝑈 ∙ 𝐼

wind turbine efficiency

Operational characteristics of the wind turbine 8

Optimal electrical load determination

• Measuring of U and I at different electrical resistances (R) at maximum possible

wind speed in the wind tunnel.

• Determination of the electrical resistance for maximum electrical power of the

generator.

9

𝑅 𝒊

t U [V] I [A]

𝑡1 𝑢1 𝑖1

𝑡2 𝑢2 𝑖3

𝑡3 𝑢3 𝑖4

𝑡4 𝑢4 𝑖5

⋮ ⋮

𝑡𝑛 𝑢𝑛 𝑖𝑛

𝑢𝑖𝑛

𝑖𝑛𝑛 𝑃𝑖 = 𝑈 ∙ 𝐼

Operational characteristics of the wind turbine

Electrical currents, voltages and power of generator

Operational characteristics of the wind turbine

Power

Current

Resistance

Voltage

Charateristics of the wind turbine

• The optimal load set up for maximum power

• Measuring of el. currents, voltages, rotational frequency and wind speed.

11Operational characteristics of the wind turbine

Power

Speed

TASKS

• Mesure the electrical current and the voltage at different

loads of wind turbine

• Draw the I (U) and P(U) characteristics and determine

maximum power and resistance (load) at maximum

power

• Draw the P(v) CHARACTERISTICS

• Calculate the efficiency of the wind turbine

Operational characteristics of the wind turbine