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Three-dimensional models of a plate methanol steam micro-reformer and a methanol catalytic combustor with parallel flow fields and serpentine flow fields have been established. The effects of the flow field design and the fuel flow rate on the methanol conversion and transport phenomena in the micro-reformer were investigated. The results revealed that the methanol conversion of the micro-reformer with the serpentine flow field and the combustor with the serpentine flow field has been optimized as a result of improved thermal management in the micro-reformer with combustor. With a change in flow field design from the micro-reformer and the combustor with parallel flow fields to the micro-reformer and combustor with the serpentine flow fields a wall temperature increase from 225 °C to 237 °C was observed. The methanol conversion of the micro-reformer with the serpentine flow field and the combustor with the serpentine flow field could be improved by 23% relative to the employment of a parallel flow field. A numerical model provided an efficient way to characterize the transport phenomena within the micro-reformer and combustor; the results will benefit the future design of plate methanol steam micro-reformers with combustors.

This paper presents a new single-pole switching scheme for depressing turbine–generator blade torsional torque. Since the single-phase fault occurs more frequently in power line accidents, there are many advantages on stability and reliability by using single-pole switching on the faulty phase. Nevertheless, the two healthy phases still maintain power transmission during the dead time between single-pole tripping and line reclosing, which induce significantly negative-sequence current flowing into the nearby turbine–generator. This would cause super-synchronous resonance (SPSR) effect on low-pressure (LP) turbine blades and even result in fatigue damage. The short-time compensation of a grounding capacitor set up at the neutral of the wye transformer is proposed to eliminate this negative-sequence current. Then the induced adverse effect on blades can be precluded.

The long-term effect of noncharacteristic harmonic currents in asynchronous HVDC links on fatigue life expenditure in turbine–generator blades is studied in this paper. Because the frequencies of the two main harmonic current terms are subsynchronous and offer a probability distribution due to the asynchronous operation in a HVDC link, a systematic fatigue estimation approach was devised to investigate the long-term impact for the low-pressure turbine blades. From the simulation results, it is clear that the sustained excitation of these harmonics becomes a cause of blade failure even though the harmonic current is still normal for only one generator connected to the inverter station bus. By the effect analysis of uncertainty in electrical and mechanical parameters, several schemes for the fatigue loss alleviation were then found.