ansaction project to maximize the total revenue and minimize the associated risks considering cost of electricity and ramping constraints. So it is wohwhile studying how to allocate the generation capac- ity to the multi-electricity markets in multi-scale time. The paper presents a multi-scale temporal bidding combination model by introdu- cing the economic concept of utility and risk management. The computation and analysis sults of a numerical example are detailed, which shows that adopting the competitive model is helpful for power generators to optimal bidding combination project within the trans- action day. Key words; power market; bidding combination; ramping constraint; risk management; utility