Low carbonization is the primary target in power system operation at present

while the abrupt arrangements of the setup of interests is one of the greatest obstacles to affect transfer to low carbon emission among power units. This paper studies the equity issues in low-carbon electric dispatch problems. A low-carbon dispatch model with carbon emission permit constraints is proposed. In China

units are granted carbon emission allowance claims from the government. This paper applies fair allocation based on the claim theory for solving the controversial problem in carbon emission allowance fair allocation. The cooperative game mechanism in unit carbon emission allowance allocation is investigated

and a comparison is made in the unit operation state between cooperative and noncooperative carbon reducing mechanism. A Shapley value-based model is developed to allocate the cooperative surplus fairly. The study shows the cooperative mechanism for carbon reduction can optimize power system operation and balance the interests of different units

which will facilitate actual implementation of low carbon electric dispatch. The study has also found that if the carbon reduction target is set excessively high

the generation cost may rise dramatically and in the worst case cause load shedding. Finally

a numerical example shows that the proposed model is effective.