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When matrix converter (MC) and high-frequency link (HFL) are combined together, they become more complex and gain a safe commutation for the use of high-frequency transformer. To realize energy conversion and transmission, and to achieve reliable and safe commutation at the same time are particularly important and desirable. HFL matrix converter (HFLMC) can be divided into two types: high-frequency link matrix inverter (HFLMI) and high-frequency link matrix rectifier (HFLMR). A three-phase output HFLMI is selected as the object of this study, and a novel integration sinusoidal pulse width modulation (SPWM) control strategy with one-step adaptive commutation based on De-Re-coupling idea is proposed for it. After expounding on the De-Re-coupling idea, a kind of HFLMC equivalent circuit model based on the high-frequency transformer equivalent circuit is built up. Then, a detailed analysis of the voltage stress on power devices of the HFLMC by using this model is performed. A safe operation evaluation criterion of HFLMC is also gained. A suggestion of how to select carrier wave for integration SPWM is ascertained through detail discussion, and two kinds of specific Re-coupling logic circuits are presented, and at last some experimental results are shown to make a certification for feasibility and effectiveness of the new proposed SPWM strategy. [ABSTRACT FROM AUTHOR]

The secondary aluminum ash is the black slag left after the primary aluminum ash is extracted from the metal aluminum. To address the environmental pollution and resource waste caused by the accumulation and landfill of aluminum ash, this study fabricated non-fired bricks by using secondary aluminum ash as the principal raw material, which was supplemented by cement, slaked lime, gypsum and engineering sand. The effects of mix proportions of various admixtures on the mechanical properties of non-fired bricks were investigated, and on this basis, the hydration mechanism was analyzed. The results showed that the mix proportions were 68.3% aluminum ash, 11.4% cement, 6.4% slaked lime, 4.2% gypsum and 9.7% engineering sand. The compressive strength of the fabricated bricks reached 22.19 MPa, and their quality indicators were in line with the MU20 requirements for Non-fired Rubbish Gangue Bricks. Evident hydration reaction occurred inside the non-fired bricks, with main products being calcium silicate hydrate (CSH), calcium aluminate hydrate (CAH) and ettringite (AFt). Besides, a dense structure was formed, which enhanced the brick strength. [ABSTRACT FROM AUTHOR]