Computing the Maximum Penetration Level of Multiple Distributed Generators in Distribution Network Taking into Account Voltage Regulation Constraints

An optimization method is proposed for computing the maximum penetration level of multiple distributed generators,taking into account voltage regulation constraints.Under-load tap changing transformer is modeled using a switch function,and the impact of distributed generator outage is included.We analyze how the location of distributed generators affects penetration level,and suggest a bi-level optimization model to accommodate this effect.In the proposed mathematical model,the penetration level of distributed generators is maximized in the upper level optimization,while the lower level optimization ensures that voltage constraints are satisfied even under the worst case.Numerical algorithms are described in sufficient detail,together with test results of a 112 bus system.