Ethereum, as a representative of Web3, adopts a novel framework called Proposer Builder Separation (PBS) to prevent the centralization of block profits in the hands of institutional Ethereum stakers. Introducing builders to generate blocks based on public transactions, PBS aims to ensure that block profits are distributed among all stakers. Through the auction among builders, only one will win the block in each slot. Ideally, the equilibrium strategy of builders under public information would lead them to bid all block profits. However, builders are now capable of extracting profits from private order flows. In this paper, we explore the effect of PBS with private order flows. Specifically, we propose the asymmetry auction model of MEV-Boost auction. Moreover, we conduct empirical study on Ethereum blocks from January 2023 to May 2024. Our analysis indicates that private order flows contribute to 54.59% of the block value, indicating that different builders will build blocks with different valuations. Interestingly, we find that builders with more private order flows (i.e., higher block valuations) are more likely to win the block, while retain larger proportion of profits. In return, such builders will further attract more private order flows, resulting in a monopolistic market gradually. Our findings reveal that PBS in current stage is unable to balance the profit distribution, which just transits the centralization of block profits from institutional stakers to the monopolistic builder.

Cascaded grid-connected inverter has good application prospects in large-capacity grid-connected photovoltaic systems. It helps to solve the problem of lower generation efficiency caused by unequal irradiance between PV arrays. This paper studies Low Voltage Ride Through (LVRT) control strategy of cascaded inverter for grid-connected photovoltaic systems under asymmetric grid fault conditions. The mathematical model of voltages in grid side is researched under asymmetric grid fault conditions. The law of amplitude and phase of three phase voltages in grid side is summarized under different fault conditions. The control method of cascaded inverter for grid-connected PV systems is analyzed based on the above law, and the low voltage through control strategy based on bypass principle is proposed. Finally the simulation model of the low voltage through control strategy of cascaded inverter for grid-connected PV systems is established. The correctness and effectiveness of control strategy design are verified by simulation under fault conditions.