Comparison of Two Three-Phase PLL Systems for More Electric Aircraft Converters

Abstract

A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription. Abstract-The More Electric Aircraft power system is characterized by variable supply frequency, in general between 360Hz and 900Hz. All equipment on board the aircraft have to operate delivering high performance under this variable frequency condition. In particular, power electronic converters need accurate control algorithms able to track the fundamental phase and frequency in real time, both in normal and unusual conditions. Phase Locked Loop (PLL) based algorithms are commonly used in traditional single and three phase power systems to provide phase and frequency estimations of the supply. Despite the simplicity of those algorithms, large estimation errors can arise when power supply voltage has variable frequency or amplitude, presents unbalances or is polluted with harmonics. To improve the quality of the phase and frequency real-time estimations, a robust PLL algorithm, based on a predictioncorrection filter, is presented in this paper and compared with a Discrete Fourier Transform (DFT) based procedure. The performances of the two algorithms, implemented in a floatingpoint DSP, have been compared through an experimental validation obtained on a laboratory power converter prototype.

An Improved Voltage Compensation Approach in A Droop-Controlled DC Power System for the More Electric Aircraft

“…For the CCL case, the operating point will go to op 2 where the current is kept the same as in initial operation point op 0 . If the proposed method is applied for CIL, the EPS new equilibrium point will be at op 3 . In all cases, under the action of the proposed feedforward link, the DC bus voltage is restored to the reference value.…”

“…MEA development introduces many challenges for the onboard electrical power system (EPS) design due to the substantially increased power demand [3] and the associated impact on the generation and distribution sub-systems. Among the possible distribution topologies, for example AC, DC, hybrid, frequency-wild and others [1], architectures with DC distribution have attracted significant research interest due to their potential advantages such as lower total weight, higher efficiency and reduced cost [4].…”

Steady-State Linear Kalman Filter-Based PLLs for Power Applications: A Second Look

“…In designing this PLL, it is assumed that large frequency ramping changes during normal operating conditions are likely. Based on this assumption, the following three-state prediction model is considered [9], [10] x(n) = Ax(n − 1)…”

An Overview of Power Electronics Techniques in Electric Systems for Transport Applications

“…Meanwhile, it is less sensitive to harmonics, noise, and signal amplitude variations. Furthermore, a robust PLL algorithm was raised by using a predictioncorrection filter in [45], which was experimentally compared with the aforementioned DFT-PLL proposed in [44]. This PLL solution is based on a third-order linear and time-invariant observation model, which is obtained from a steady-state linear Kalman filter (SSLKF), and the computation burden was mitigated since the calculation of the correction gain vector can be done offline.…”