This paper calculates the land (including water area) requirement for food consumption in both balanced andactual diet in China by ecological footprint analysis. To determine whether logical and actual food demands ar...This paper calculates the land (including water area) requirement for food consumption in both balanced andactual diet in China by ecological footprint analysis. To determine whether logical and actual food demands are withinnatural regenerative ability, carrying capacity (excluding forestry production) is also calculated. Results show that actualdiet patterns were ecologically friendly in the period of 1982-2004 in China, mainly because of the rural moderate dietpatterns. But actual per capita footprint already overran its corresponding logic value of 0.976ha in urban areas in 2002.Productive areas for food production can satisfy the land requirement for actual diet patterns during the researchingperiod in China, nevertheless cannot satisfy that for balanced diet pattern or solve the problem of unbalanced ecologicalfootprint. The continual rising ecological footprint of food consumption in both rural and urban areas indicates that percapita footprint will keep on increasing in China and even may be more than the suggested logic value if no relevantcountermeasures are made to regulate diet patterns. Strictly speaking, China is facing food shortage, both in quality andin quantity.展开更多
China is vigorously promoting the “whole county promotion” of distributed photovoltaics (DPVs). However, the high penetration rate of DPVs has brought problems such as voltage violation and power quality degradation...China is vigorously promoting the “whole county promotion” of distributed photovoltaics (DPVs). However, the high penetration rate of DPVs has brought problems such as voltage violation and power quality degradation to the distribution network, seriously affecting the safety and reliability of the power system. The traditional centralized control method of the distribution network has the problem of low efficiency, which is not practical enough in engineering practice. To address the problems, this paper proposes a cluster voltage control method for distributed photovoltaic grid-connected distribution network. First, it partitions the distribution network into clusters, and different clusters exchange terminal voltage information through a “virtual slack bus.” Then, in each cluster, based on the control strategy of “reactive power compensation first, active power curtailment later,” it employs an improved differential evolution (IDE) algorithm based on Cauchy disturbance to control the voltage. Simulation results in two different distribution systems show that the proposed method not only greatly improves the operational efficiency of the algorithm but also effectively controls the voltage of the distribution network, and maximizes the consumption capacity of DPVs based on qualified voltage.展开更多
文摘This paper calculates the land (including water area) requirement for food consumption in both balanced andactual diet in China by ecological footprint analysis. To determine whether logical and actual food demands are withinnatural regenerative ability, carrying capacity (excluding forestry production) is also calculated. Results show that actualdiet patterns were ecologically friendly in the period of 1982-2004 in China, mainly because of the rural moderate dietpatterns. But actual per capita footprint already overran its corresponding logic value of 0.976ha in urban areas in 2002.Productive areas for food production can satisfy the land requirement for actual diet patterns during the researchingperiod in China, nevertheless cannot satisfy that for balanced diet pattern or solve the problem of unbalanced ecologicalfootprint. The continual rising ecological footprint of food consumption in both rural and urban areas indicates that percapita footprint will keep on increasing in China and even may be more than the suggested logic value if no relevantcountermeasures are made to regulate diet patterns. Strictly speaking, China is facing food shortage, both in quality andin quantity.
基金the National Key R&D Plan Program of China(Grant No.2022YFE0120700)the Special Fund for Science and Technology Innovation of Jiangsu Province(Grant No.BE2022610)Zhuhai Industry Core Technology and Key Project(Grant No.2220004002344).
文摘China is vigorously promoting the “whole county promotion” of distributed photovoltaics (DPVs). However, the high penetration rate of DPVs has brought problems such as voltage violation and power quality degradation to the distribution network, seriously affecting the safety and reliability of the power system. The traditional centralized control method of the distribution network has the problem of low efficiency, which is not practical enough in engineering practice. To address the problems, this paper proposes a cluster voltage control method for distributed photovoltaic grid-connected distribution network. First, it partitions the distribution network into clusters, and different clusters exchange terminal voltage information through a “virtual slack bus.” Then, in each cluster, based on the control strategy of “reactive power compensation first, active power curtailment later,” it employs an improved differential evolution (IDE) algorithm based on Cauchy disturbance to control the voltage. Simulation results in two different distribution systems show that the proposed method not only greatly improves the operational efficiency of the algorithm but also effectively controls the voltage of the distribution network, and maximizes the consumption capacity of DPVs based on qualified voltage.
