LS-Solar-PV System Impact on Line Protection

Abstract

Large-scale photovoltaic power station access to the grid will profoundly change the fault current characteristics of the power station’s outgoing lines. This change results in adaptive problems in traditional protection phase selection components, which may cause incorrect actions in reclosing, protection ranging, and distance protection. Based on the fault current characteristics of the large-scale photovoltaic power station transmission line, this paper analyzes the adaptability of the phase current difference mutation and the sequence component phase selection component in protecting the Photovoltaic (PV) power plant side of the transmission line. Based on the fault current analytical formula, the phase relationship between the phase current difference and the current sequence component under different control targets, such as suppressing negative sequence current, suppressing the active power fluctuation, and suppressing the reactive power fluctuation, is derived. The operational performances of the phase–phase current difference of the abrupt phase selection component and the sequence component phase selection component of the power station side are degraded, which may cause incorrect operation of the phase selection component. Based on the actual engineering parameters of a PV power plant, a simulation model was built in Power System Computer Aided Design (PSCAD) to verify the correctness of the theoretical analysis.

An Efficient Scheme for Determining the Power Loss in Wind-PV Based on Deep Learning

“…In this paper, the DBN-DNN model source training data adopts the data of August 2019 (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20), and the data of the task to be calculated adopts the data of August 21, 2020. Due to the randomness of the output of wind power and photovoltaic power, the model training and calculation are difficult.…”

“…In addition, the data required for calculation will be missing, incomplete collection or collection errors [12]. Therefore, finding a fast, accurate, and highly error-tolerant theoretical online calculation method for the loss of data, so as to formulate practical loss reduction measures to reduce the loss of the network, is an urgent problem for power companies to solve [13][14].…”

Solar PV Grid Power Flow Analysis

“…Based on the above structure, the steady state construction of the PV cell is used in this paper, for which the analog equivalent circuit is shown in Figure 3, where I PH is the photo-generated current of the semiconductor PN junction, I D is PN junction forward conduction current, R L and R S are the leakage resistance and contact resistance between the electrodes on both sides of the PN junction, and I L is the inter-electrode leakage current. The characteristic function is a single exponential equivalent model [29,30], as follows:…”

“…In this paper, = , ≈ , and ≈ ∞ are approximated in the modeling, so that the external characteristics of the PV cell are simplified to Formula (5), and the relationship between parameters , and the respective feature quantities, is as shown in Formula (6). The characteristic function is a single exponential equivalent model [29,30], as follows:…”

“…Probabilistic currents can reflect the impact of this uncertainty on the operation of the system, and are an important basis for solving the weak links in the power grid. The authors of [29] proposed a probabilistic power flow calculation method by combining a semi-invariant and Gram-Charlier series expansion. In the literature [30], a probabilistic power flow algorithm based on a stochastic configuration point method was proposed based on the uncertainty quantization theory.…”