近日，SGO课题组2015级硕士研究生沈郁投稿的两篇SCI论文被接收，其中英文论文“Yu Shen, Wei Yao, Jinyu Wen, Haibo He. Adaptive Wide-area Power Oscillation Damper Design for Photovoltaic Plant Considering Delay Compensation.”被华中科技大学B类SCI期刊《IET Generation, Transmission and Distribution》接收。英文论文“Yu Shen, Wei Yao, Jinyu Wen, Haibo He, Weibiao Chen. Adaptive Supplementary Damping Control of VSC-HVDC for Interarea Oscillation Using GrHDP.”被电力系统领域国际著名期刊《IEEE Transactions on Power Systems》接收。

近年来，自适应动态规划算法被认为是一种非常接近人脑的智能算法，它集神经网络、近似动态规划和强化学习于一体，利用非线性函数拟合方法逼近性能指标，克服了传统动态规划求解时的“维数灾”问题。该算法不需要系统模型，因此避免了模型参数不准确的问题，能很好地解决大规模非线性系统的最优控制问题，已被应用到交通、物流、电力等大量科学领域。1977 年Werbros 提出的启发式动态规划(heuristic dynamic programming，HDP)是一种最基本、使用最普遍的自适应动态规划模型，但其强化信号只由某一固定值或某一固定函数所构成，因此所设计的强化信号不能适应系统运行状态的改变，从而导致HDP 的控制性能难以总保持最优。为了适应电力系统时变的控制要求，2012年美国罗德岛大学的何海波教授提出了具有3 个神经网络结构的GrHDP(goal representation heuristic dynamic programming)模型。GrHDP 的优势在于，新增的目标网络能形成一个自适应的内部强化信号，更好地调节输入信号与输出控制量之间的映射关系，从而大大改善系统的动态性能和控制效果。

论文“Adaptive Wide-area Power Oscillation Damper Design for Photovoltaic Plant Considering Delay Compensation”利用GrHDP 算法和自适应时滞补偿器设计了光伏附加阻尼控制器，用于阻尼含光伏电力系统的功率振荡。所构造的阻尼控制器具有在线自学习能力，能通过目标函数和强化信号调整控制策略，提高对区域间振荡的阻尼能力，并且能适应不同的系统工况。同时，所采用的自适应时滞补偿器能很好地补偿通信网络造成的广域信号时滞。通过IEEE 16机68节点系统算例验证了所设计的光伏附加阻尼控制器在不同工况下均能很好地补偿输入信号的时滞、抑制系统功率振荡。

论文“Adaptive Supplementary Damping Control of VSC-HVDC for Interarea Oscillation Using GrHDP”利用GrHDP 算法设计了柔性直流附加阻尼控制器，用于阻尼交直流系统中的功率振荡。由于GrHDP控制器采用BP神经网络实现，输出信号的相位无法产生相对于输入信号的较大偏移，因此本文提出了一个并联相位偏移通道，将原输入信号和经该通道后的相位偏移信号同时作为控制器的输入信号，通过神经网络的权值自适应调整，控制器就可以实现任意大小的相位补偿。论文在IEEE 10机39节点和IEEE 16机68节点系统中均进行了算例验证，仿真结果表明增加相位偏移通道后，控制器能实现合适的相位补偿，并且其在不同运行工况下的低频振荡抑制效果要优于常规超前滞后控制器和HDP控制器。

以下为两篇论文的摘要：

Adaptive wide-area power oscillation damper design for photovoltaic plant considering delay compensation

Yu Shen, Wei Yao , Jinyu Wen, Haibo He

Abstract: With the increasing amount of grid-connected photovoltaic (PV) plants in a power system, the volatility and uncertainty of power generated from PV plants may adversely impact on the power system stability, for example increasing the risk of interarea oscillation. To solve the problem, this study proposes an adaptive wide-area power oscillation damper (WPOD) based on goal representation heuristic dynamic programming (GrHDP) algorithm for PV plant to enhance damping of the concerned interarea mode. By using GrHDP, the adaptive WPOD (A-WPOD) does not need the model of the power system and has adaptivity to different operating conditions. Moreover, an adaptive delay compensator is also employed for the proposed AWPOD to compensate the communication delay existing in the wide-area signal. Case study is carried out on a 16-machine 68-bus system with a large-scale PV plant. Simulation results show that the A-WPOD can provide satisfactory damping performance and compensate the communication delay over a wide range of operating conditions.

Adaptive Supplementary Damping Control of VSC-HVDC for Interarea Oscillation Using GrHDP

Yu Shen, Wei Yao, Member, IEEE, Jinyu Wen, Member, IEEE, Haibo He, Senior Member, IEEE, Weibiao Chen

Abstract: Interarea oscillation is one of the main challenges for the secure and stable operation of a large-scale interconnected power system. To address this problem, this paper presents an adaptive supplementary damping controller (SDC) for voltage source converter based high voltage direct current (VSC-HVDC) by using the goal representation heuristic dynamic programming (GrHDP). Compared with conventional heuristic dynamic programming (HDP), GrHDP adds a new goal representation network to generate an adaptive reward signal to achieve better mapping relationship between the system states and the control action. To compensate phase shift between the output and input signals of a complex AC/DC power system, this paper proposes a parallel phase shift channel for the GrHDP. Moreover, the proposed GrHDP-SDC is a model-free control scheme, which does not need the mathematic model of the power system and has quick online learning ability to adapt to the variation of system operating conditions. Case studies are carried out on the 10-machine 39-bus system and 16-machine 68-bus system, respectively. Compared with the conventional lead-lag SDC (LLSDC) and HDP-SDC, simulation results show that the proposed GrHDP-SDC can always provide satisfactory damping performance over a wide range of system operating conditions and disturbances.