State Estimation for Situational Awareness of Active Distribution System With Photovoltaic Power Plants

2021 ◽  
Vol 12 (1) ◽  
pp. 239-250
Author(s):  
Zhi Fang ◽  
Yuzhang Lin ◽  
Shaojian Song ◽  
Chi Li ◽  
Xiaofeng Lin ◽  
...  
2020 ◽  
Vol 182 ◽  
pp. 106247
Author(s):  
Zhi Fang ◽  
Yuzhang Lin ◽  
Shaojian Song ◽  
Chunning Song ◽  
Xiaofeng Lin ◽  
...  

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3208 ◽  
Author(s):  
Xiangyu Li ◽  
Dongmei Zhao ◽  
Baicang Guo

In order to build an active distribution system with multi virtual power plants (VPP), a decentralized two-stage stochastic dispatching model based on synchronous alternating direction multiplier method (SADMM) was proposed in this paper. Through the integration of distributed energy and large-scale electric vehicles (EV) in the distribution network by VPP group, coordinative complementarity, and global optimization were realized. On the premise of energy autonomy management of active distribution network (AND) and VPP, after ensuring the privacy of stakeholders, the power of tie-line was taken as decoupling variable based on SADMM. Furthermore, without the participation of central coordinators, the optimization models of VPPs and distribution networks were decoupled to achieve fully decentralized optimization. Aiming at minimizing their own operating costs, the VPPs aggregate distributed energy and large-scale EVs within their jurisdiction to interact with the upper distribution network. On the premise of keeping operation safe, the upper distribution network formulated the energy interaction plan with each VPP, and then, the global energy optimization management of the entire distribution system and the decentralized autonomy of each VPP were achieved. In order to improve the stochastic uncertainty of distributed renewable energy output, a two-stage stochastic optimization method including pre-scheduling stage and rescheduling stage was adopted. The pre-scheduling stage was used to arrange charging and discharging plans of EV agents and output plans of micro gas turbines. The rescheduling stage was used to adjust the spare resources of micro gas turbines to deal with the uncertainty of distributed wind and light. An example of active distribution system with multi-VPPs was constructed by using the improved IEEE 33-bus system, then the validity of the model was verified.


2021 ◽  
Vol 9 ◽  
Author(s):  
Xingzhen Bai ◽  
Xinlei Zheng ◽  
Leijiao Ge ◽  
Feiyu Qin ◽  
Yuanliang Li

In this study, the forecasting-aided state estimation (FASE) problem for the active distribution system (ADS) with distributed generations (DGs) is investigated, considering the constraint of data transmission. First of all, the system model of the ADS with DGs is established, which expands the scope of the ADS state estimation from the power network to the DGs. Moreover, in order to improve the efficiency of data transmission under the limited communication bandwidth, a component-based event-triggered mechanism is employed to schedule the data transmission from the measurement terminals to the estimator. It can efficiently reduce the amount of data transmission while guaranteeing the performance of system state estimation. Second, an event-triggered unscented Kalman filter (ET-UKF) algorithm is proposed to conduct the state estimation of the ADS with mixed measurements. To this end, the unscented transform (UT) technique is employed to approximate the probability distribution of the state variable after nonlinear transformation, which can reach more than second order, and then, an upper bound of the filtering error covariance is derived and subsequently minimized at each iteration. The gain of the desired filter is obtained recursively by following a certain set of recursions. Finally, the effectiveness of the proposed method is demonstrated by using the IEEE-34 distribution test system.


2021 ◽  
Vol 72 (2) ◽  
pp. 140-147
Author(s):  
František Janíček ◽  
Ján Poničan ◽  
Matej Sadloň

Abstract The article analyzes electricity prices in Slovakia, their distribution tari component, and their significant impact on small-scale photovoltaic power plants (PVPs). Fixed part of the distribution tari component in Slovakia varies considerably, given the region of operation of the distribution system operator as well as the allocated tari rate. Profitability of the small-scale PVP in Slovakia is widely discussed, with differing opinions of the lay and professional public. The article will explain under what circumstances all the opinions may be true. Profitability predictions available online or done by PVP installers are extremely simplified and lead to misleading results. The existence of fixed and variable components of the price plays a significant role and a simple change of the electricity tari may bring significant savings and shorten the payback time of the PVP investment. However, this is a complex issue and requires several other factors to be considered, too. The most important ones are the fixed component of the electricity price, household consumption diagram and the distribution system to which the household is connected.


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