Mission profile resolution effects on lifetime estimation of doubly-fed induction generator power converter

Abstract

Abstract-In the wind energy generation system, mission profiles are complicated, which range from seconds to years. In order to estimate the consumed lifetime of the power converter, wind speed profiles with the time resolution of 1 hour, 1 second and 0.5 millisecond are studied in this paper, and the corresponding thermal modeling of power semiconductors are discussed. Accordingly, effects of different mission profiles on the consumed lifetime of the power converter are evaluated. In the above three thermal cycles, the IGBT of the grid-side converter and the diode of the rotor-side converter are more fragile, and the total consumed lifetimes are higher. Moreover, the short-term thermal cycles with milliseconds resolution induce the unbalance of the lifetime between the diode and IGBT of the grid-side converter, while thermal cycles with hour, second, and millisecond resolution consumes the similar lifetime of the power components in the rotor-side converter. Furthermore, it is concluded that the lifetime of power components reduces with the increased time resolution, especially for the rotor-side converter.

Modelling of Wind Turbine Operation for Enhanced Power Electronics Reliability

“…Reference losses 𝐸 𝑜𝑛+𝑜𝑓𝑓 𝑟𝑒𝑓 and 𝐸 𝑟𝑟 𝑟𝑒𝑓 are given in datasheets as the polynomial function in (17). The average switching losses, using (15) and as a function of phase-current Ic and switching frequency fsw, as well as the sum of the energy loss of all the switching transients given with (18), are calculated with (19) [31], [32].…”

“…There are established practices for the evaluation of lifetime based on this failure mode, but there exists a level of ambiguity in mapping the operational root-causes to the failure mechanism [9], [15]. In previous research, different approaches have been used to account for the higher resolution thermal transients while also looking at a substantial period of WT operation when estimating thermal loading and lifetime consumption [9], [16], [17]. Some operational aspects have been included as part of the mission profile.…”

Adequacy Evaluation of an Islanded Microgrid

“…Similarly, the power losses dissipated in the capacitors can be obtained by considering the dc-link ripple current subjected to the equivalent series resistance (ESR). More detailed descriptions of the mission profile translations of power devices and capacitors can be found in [14,34,[38][39][40], respectively. For long-term simulation, some well-suited operating conditions are defined, and the corresponding conduction and switching losses along with the thermal impedance of the power device are inserted in look-up tables, assisted with the interpolation method of choice [41,42].…”

“…The lifetime estimation is based on the accumulation of damage caused by each of the cycles contained in the annual stress profile, as shown in Figure 9. A widely used assumption is the linear damage accumulation, which is known as Miner's rule and which can be expressed as [39]:…”

Component-Level Reliability Assessment of a Direct-Drive PMSG Wind Power Converter Considering Two Terms of Thermal Cycles and the Parameter Sensitivity Analysis

“…Therefore, the only calculation of the long-term thermal cycles is not enough. Although the resolution of the wind mission profile has been reduced to at least 1s in [10]- [13] for the reliability assessment of both the full-scale and the partial-scale power converters, they were still long-term calculations inherently and cannot reflect the damage performance under short-term thermal stress, whose frequency is usually from several to dozens of Hz. In other words, the calculation of the short-term thermal stress cannot be realized merely by improving the sampling resolution of the annual wind speed profile, it should be calculated under different wind speeds in a paralleled manner considering their annual distributions.…”