A Research On The Relevant Issues Of Power System Planning Under Low-Carbon Economy

As an important industry of fossil energy consumption, carbon emission of power industry in China accounts for nearly forty percent of the total emission. In an environment of low-carbon economy, carbon emissions of power system will be strictly restricted by the country’s overall emissions reduction policies and patterns. Moreover, the introduction of carbon trading mechanism and low-carbon electric technologies will have a significant impact on the development of power industry. As an effective measure to ensure the healthy development of power industry, power system planning should meet the requirement of low-carbon economy. In this paper, the problems of power system planning under low-carbon economy are studied with the emergence of new factors and their impact into consideration, and some conclusions are obtained as follow.(1) The low-carbon factors, such as low-carbon electric technologies, carbon trading mechanism and penalty mechanism for exceeding emission allowance, are modeled with analyzing their impact on power system planning. The characteristics of energy flow and operation of Carbon Capture Plants (CCPs) are clarified, while the mutual constraint between total/net generation output of CCPs and running consumption of carbon capture system ("T-R" and "N-R" constraints) is analyzed.(2) A multi-period generation output model and the operation optimization method of CCPs are established, which can identify how the amount of carbon captured can represent a premium payment that can offset the increase in costs caused by the reduction on power output due to the Carbon Capture and Storage (CCS) installations. On this basis, what with the low-carbon economy factors, an operation optimization model under low-carbon economy with CCPs considered is proposed. With the generation fuel cost and carbon emission cost incorporated in the objective function, the model proposed can effectively evaluate the power dispatch problem under low-carbon economy. Studies of the ED of the3-units and54-units test systems show that the model proposed is effective and practical.(3) The carbon capture output of CCP is treated as a new Spinning Reserve (SR) source for power system operation, and then a model for optimizing SR requirement of power system is proposed under low-carbon economy. The proposed model takes the minimization of the overall cost as the objective function, which includes generation cost, Expected Energy Not Supplied (EENS) cost and carbon emission cost, aiming to provide a more comprehensive evaluation method for SR requirement of power system under low-carbon economy. Studies of SR optimization based on the IEEE-RTS-96system is studies, and the impact of carbon trading price, carbon emission credit, and Value Of Lost Load (VOLL) on SR requirement is analyzed to reveal the model’s adaptability and feasibility.(4) A "4-area" carbon emission trajectory model based on total emission constrain is improved and introduced into the Generation Expansion Planning (GEP), thus establishing a model for generation expansion planning based on the carbon emission trajectory model under low-carbon economy. In this model, the cost of carbon emission and the planning of CCPs are focused, while the carbon emission of power system is considered under the constraint of China’s long-term emission reduction policy. An actual case is studies based on one provincial grid in China by applying the proposed model, and the impact of carbon trading price, investment of CCS is also analyzed. The results prove the model proposed to be more adaptable and effective for the sustainable development of future power system.(5) With carbon emissions cost arising from transmission loss and wind/water spillage incorporated into the objective function, an optimization model for Transmission Network Expansion Planning (TNEP) under low-carbon economy is proposed. And the emphasis is on the fuzzify calculation method of wind/water energy spillage caused by transmission capacity deficiency and the low-carbon adjustment strategy of generators for coping with the overloading problem, which may have a significant impact on the CO2emissions cost of power grid operation. An illustrative example based on the modified New England (NE)39-bus system is analyzed to show that the model proposed is effective and practical.