URBANIZATION AND SUSTAINABLE FOOD PRODUCTION IN CHINA

China is now facing urbanization and the migrants from rural area have increased significantly. The farmland was the core iuess of the new urbanization process. The contracted land management right, residence land use rights and collective construction land allocation right were the main contents of the property right of peasants. To establish a new mechanism to make peasants and the rural collective enjoy the reasonable land profit is important for the new round land reform in China. Based on that, this paper will explain how the rural land were transformed into urban poverty. This paper argued that replace rural retained land into urban property model was a new form of compensation for the rural land.  By this model, the migrant farmers can obtain the compensation as the economic base in city and improve the willingness of farmers moving to city and transfer their land to enlarge average arable land scale to develop food production. The paper concluded that the way to solve the shortage of arable land was to speed up the process of urbanization, promote the circulation of cultivated land to realize the expansion of rural per capita arable land to ensure food security. Therefore, it is needed to build a unified construction land market, realize the same price and same right between state-owned land and rural collective land, giving farmers more property rights

Optimized Hierarchical Power Oscillations Control for Distributed Generation Under Unbalanced Conditions

Control structures have critical influences on converter-interfaced distributed generations (DG) under unbalanced conditions. Most of previous works focus on suppressing active power oscillations and ripples of DC bus voltage. In this paper, the relationship between amplitudes of the active power oscillations and the reactive power oscillations are firstly deduced and the hierarchical control of DG is proposed to reduce power oscillations. The hierarchical control consists of primary and secondary levels. Current references are generated in primary control level and the active power oscillations can be suppressed by a dual current controller. Secondary control reduces the active power and reactive power oscillations simultaneously by optimal model aiming for minimum amplitudes of oscillations. Simulation results show that the proposed secondary control with less injecting negative-sequence current than traditional control methods can effectively limit both active power and reactive power oscillations.Comment: Accepted by Applied Energ