Abstract: Abstract: To avoid the calculation of limit access capacity of photovoltaic (PV) source is incorrect due to the consideration of the occurrence of a small probability event, this paper proposes a method to calculate the limit access capacity of photovoltaic (PV) source based on the chance onstraints of voltage deviation on the basis of considering the randomness of PV power and load. Maximizing limit access capacity of PV is regarded as the goal, the voltage deviation is regarded as the chance constrained condition, the calculation model of limit access capacity of PV is established. Then, the statistical properties of node voltage are obtained by using the LHS and Newton-Raphson to calculate the probabilistic load flow (PLF). Calculation results of PLF and quantum genetic algorithm are used to solve the model. By comparing the results of optimization with heuristic method, the correctness and validity of the proposed method are verified.