## 1 Introduction  
With the rise of 'net-zero' initiatives, the power and energy sector has been continuously deepening its low-carbon transformation strategy, bringing unprecedented opportunities and challenges to developing and evolving new types of power systems [1, 2]. Urban distribution networks (UDNs), as the receiving end of the power grid and facing users directly, can facilitate the integration of a vast amount of distributed generation (DG) and the flexible management of user-side loads. They are an essential component in new types of power systems [3, 4]. The digital industrial upgrading process of UDNs in China is gradually accelerating, and the novel electrical load resources, mainly consisting of 5G base stations and Internet data centers (IDCs), are experiencing rapid growth. As a result, UDNs typically exhibit significant load peak-valley differences [5; 6]. However, the annual duration of peak loads in UDNs is between a dozen hours and several hours. Constructing many redundant power sources to fill short-term peak gaps is not an optimal solution in either economic or physical terms [7; 8]. Therefore, while facing short-term power shortages, UDNs possess abundant aggregable resource endowments [9]. Under such circumstances, VPPs can integrate distributed energy resources (DERs) and optimize industrial layout [10]. By leveraging intelligent computing and communication network technologies, VPPs can match the output of each generation unit within the system to the fluctuations in power demand, thereby achieving coordinated scheduling and resource mutual assistance [11; 12]. However, although VPPs can obtain economic benefits by utilizing load-side resources for peak-valley regulation, when third-party-operated VPPs focus solely on economic benefits as the optimization goal, their dispatching behavior may exacerbate voltage deviations in UDNs, posing new challenges to the safe and stable operation of UDNs. In UDNs incorporating VPPs, the line impedance exhibits resistive characteristics, with resistance values significantly higher than reactance values. As a result, adjusting the active power of various loads within the UDN can effectively control voltage deviations. As one of the active management measures for UDNs, distribution network reconfiguration indirectly adjusts loads' active power by changing the on-off status of tie switches and sectionalizing switches, thereby reducing voltage deviations and achieving efficient proactive voltage control [13; 14]. An optimization operation framework for VPPs in reconfigurable grids is proposed in [15], which integrates combined heat and power (CHP), DG, and energy storage systems to address potential voltage security issues in the grid. An optimization aggregation method for DERs in VPPs is introduced in [16], where a network partitioning model constrained by electrical distance proximity and resource complementarity is constructed to minimize internal voltage deviations within the VPP and ensure the safe and stable operation of UDNs. A coordinated optimization scheduling model for CHP-VPPs integrated with reconfigurable district heating networks is developed in [17], which simplifies computational complexity through energy flow models and employs adaptive robust optimization combined with column and constraint generation algorithms to handle wind power uncertainty, ensuring stability under extreme scenarios. However, in the existing optimization and reconfiguration of UDNs incorporating VPPs, novel electrical load resources such as 5G base stations and IDCs have not been adequately modeled. This deficiency can reduce the rationality of reconfiguration schemes and negatively impact the voltage stability of UDNs. On the other hand, the optimization and reconfiguration problem of UDNs involves many integer variables and nonlinear constraints, making it difficult to find practical and feasible solutions using traditional mathematical methods.