TY - JOUR
T1 - The Doubly Fed Induction Machine as an Aero Generator
AU - Feehally, Tom
AU - Apsley, Judith
N1 - The authors are grateful to the EPSRC, Rolls-Royce plc, and the University of Manchester Alumni Fund for supporting this research.
PY - 2015/7/15
Y1 - 2015/7/15
N2 - Modern aircraft require a robust and reliable supply of electrical power to drive a growing number of high power electrical loads. Generators are driven by a mechanical offtake from the variable speed gas turbine, while a constant frequency AC network is preferred. Here doubly-fed induction machines are advantageous since they can be controlled, through a fractionally rated converter, to decouple electrical frequency from the mechanical drive speed, making control of the network frequency possible. However, the converter must be suitably rated, according to drive speed range, electrical voltage and frequency regulation, and power requirements. This paper develops and validates a simulation model of the doubly-fed induction generator system, which is applied to find the power flow through the machine’s stator and rotor connections over a wide mechanical speed range in order to size the converter. A field orientated control scheme is implemented, to provide stand-alone voltage and frequency regulation across a drive range of ±40% synchronous speed, on a purpose-built 6.6kW hardware test platform. Based on the mechanical speed range of an aero gas turbine and the identified converter sizing, the suitability of a doubly-fed induction generator for aero applications is appraised. It is shown that a converter rated at 18% of full system rating can be used to meet the aircraft electrical specifications, and offer a potential improvement in aircraft performance, with no additional mechanical components.
AB - Modern aircraft require a robust and reliable supply of electrical power to drive a growing number of high power electrical loads. Generators are driven by a mechanical offtake from the variable speed gas turbine, while a constant frequency AC network is preferred. Here doubly-fed induction machines are advantageous since they can be controlled, through a fractionally rated converter, to decouple electrical frequency from the mechanical drive speed, making control of the network frequency possible. However, the converter must be suitably rated, according to drive speed range, electrical voltage and frequency regulation, and power requirements. This paper develops and validates a simulation model of the doubly-fed induction generator system, which is applied to find the power flow through the machine’s stator and rotor connections over a wide mechanical speed range in order to size the converter. A field orientated control scheme is implemented, to provide stand-alone voltage and frequency regulation across a drive range of ±40% synchronous speed, on a purpose-built 6.6kW hardware test platform. Based on the mechanical speed range of an aero gas turbine and the identified converter sizing, the suitability of a doubly-fed induction generator for aero applications is appraised. It is shown that a converter rated at 18% of full system rating can be used to meet the aircraft electrical specifications, and offer a potential improvement in aircraft performance, with no additional mechanical components.
KW - Aircraft
KW - Frequency regulation
KW - Generator
KW - Power converter rating
KW - Variable speed
KW - Voltage control
U2 - 10.1109/TIA.2015.2413957
DO - 10.1109/TIA.2015.2413957
M3 - Article
SN - 0093-9994
VL - 51
SP - 3462
EP - 3471
JO - I E E E Transactions on Industry Applications
JF - I E E E Transactions on Industry Applications
IS - 4
ER -