超导磁储能（superconducting magnetic energy storage，SMES）技术具有响应时间快、功率密度高、生命周期长等特点，在电网电压质量调节、频率控制、脉冲负载供电等方面具有重要的应用价值，被列为《能源技术革命创新行动计划（2016—2030）》之先进储能技术的主要突破方向。介绍了SMES的系统组成原理和系统先进性，概述了SMES在电力系统、舰船供电等场景的应用，综述了SMES近期有代表性的大型项目和研究状态，并从特性互补、提高性能的角度讨论了2种与氢电池和电化学电池组合使用的SMES混合系统。最后，指出了SMES发展和大规模应用所面临的几点挑战，并给出了相应的应对策略。

Superconducting magnetic energy storage system （SMES） has the merits of quick response, high power density, and long life-time cycle, etc Its has important applications in voltage quality control, frequency regulation, load balance and pulse power supply. SMES is listed as one of the major breakthrough directions of advance energy storage technology in “Innovative Action Plan for Energy Technology Revolution （2016-2030）”. This paper introduces the system structure of SMES and its advancement, sums up the application in the scenarios suitable for the characteristics of SMES such as power system and ship power supply, reviews the representative large-scale projects and research status of SMES, and discusses two classes of hybrid energy storage systems combined with hydrogen or electrochemical cells focusing on complementation and performance enhancement. Finally, this paper points out some challenges for the development and large-scale application of SMES, as well as the corresponding measures.

储能系统作为微电网中不可或缺的重要组成部分,对保证微电网的稳定运行和提高微电网电能质量具有重要作用。提出一种基于线性自抗扰控制(linear active disturbance rejection control,LADRC)的超导磁储能系统(superconducting magnetic storage system,SMES)储能变流器控制策略,利用LADRC能够估计并补偿系统扰动,可有效改善储能系统输出电能质量和提高系统鲁棒性。通过对LADRC和比例积分(proportional integral,PI)控制系统进行频率响应特性分析可知,一阶LADRC的反馈补偿器可以等效为一个PI控制器串联一个一阶低通滤波器,能有效抑制系统高频噪声;同时使用根轨迹法分析了LADRC控制系统的稳定性和鲁棒性。MATLAB仿真结果表明,基于LADRC的SMES储能变流器控制策略具有响应速度快、控制精度高、抗扰能力强等优点,其控制效果和鲁棒性均优于传统PI控制器。

As an indispensable and significant part of the microgrid, the energy storage system plays an important role in the stable operation of the microgrid and ensuring power quality of the microgrid. This paper proposes a control strategy for SMES energy storage converter based on linear active disturbance control (LADRC), which can estimate and compensate the system disturbance, so that it could effectively improve the power quality and robustness of the energy storage system. Analysis of the frequency response characteristics of the LADRC and PI control systems shows that the feedback compensator of first-order LADRC composed of a PI controller and a first-order low-pass filter in series can effectively suppress the high-frequency noise of the system; And the stability and robustness of the control system of LADRC are analyzed by root locus method. The MATLAB simulation results show that the control strategy for the SMES energy storage converter based on LADRC has the advantages of fast response, high control accuracy and strong anti-disturbance ability, and its control effect and robustness are both better than traditional PI controllers.

为了满足电网调控需求，提出了规模化电池储能系统平抑电网故障下大功率扰动的优化控制方法。基于电网频率、电压与有功、无功功率的平衡关系，首先建立了考虑电池荷电状态约束的规模化电池储能系统有功、无功功率控制模型，该控制模型包含测量滤波环节、增益环节、死区环节、控制环节等完整环节，在此基础上推导出适用于电网调控的规模化电池储能系统调频、调压控制模型。针对不同容量电池储能系统和电网的调控需求，应用改进的响应曲线法对模型中的控制参数进行优化，从而提高控制系统的灵活性和适应性。最后，应用PSASP软件验证了规模化电池储能系统平抑电网故障下大功率扰动的优化控制方法的有效性。结果表明：当电网大功率扰动引起电网频率、电压异常时，提出的规模化电池储能系统有功、无功控制方法可将系统频率控制在49.8~50.2 Hz，将母线电压控制在UN±10%UN，满足系统频率电压要求。

In order to meet the demand of power grid regulation， this paper proposes an optimal control method for large-scale battery energy storage to suppress the disturbance of power grid. According to the balance relationship among grid frequency， voltage， active power and reactive power， this paper firstly establishes a power control model of large-scale battery energy storage system considering the battery state of charge constraints. The control model includes measurement filtering， gain， dead zone， control and other complete links. On this basis， the frequency-modulation and voltage-regulation control model of large-scale battery energy storage suitable for grid regulation is derived. According to the regulation requirements of power grid and battery energy storage system with different capacity， the improved response-curve method is applied to optimize the control parameters in the model， so as to improve the flexibility and adaptability of the control system. Software PSASP is used to verify the effectiveness of the optimal control method of large-scale battery energy storage to suppress the disturbance of power grid. The results show that the system frequency can be controlled between 49.8~50.2 Hz and the bus voltage can be controlled between UN±10%UN using the proposed power control method when the grid frequency and voltage are abnormal due to large power disturbance.

针对超级电容储能系统(supercapacitor energy storage system, SCES)设计了一款鲁棒分数阶PID (robust fractional-order PID control, RFOPID)控制。首先,利用高增益扰动观测器(high-gain perturbation observer, HGPO)对SCES的非线性、未建模动态和参数不确定性所聚合的扰动进行实时快速估计。接着,该扰动由分数阶PID (fractional-order PID, FOPID)控制器进行完全补偿。所提控制器不依赖于精确的SCES模型,仅需测量dq轴电流,易于硬件实现。最后,通过3种算例对RFOPID控制的控制性能进行评估。仿真结果表明:与其他控制器相比,RFOPID控制在各种工况下均具有最佳的控制性能和最强的鲁棒性。

This study designs a robust fractional-order PID control (RFOPID) strategy of supercapacitor energy storage systems (SCES). At first, the nonlinearities, unmodelled dynamics and parameter uncertainties of SCES are estimated effectively by a high-gain perturbation observer (HGPO). Furthermore, a fractional-order PID (FOPID) controller is utilized to completely compensated the perturbation estimation. No accurate SCES model is required while only the dq-axis currents need to be measured, which is easy to implement in hardware. Finally, three case studies are used to evaluate the performance of RFOPID control. Simulation results show that RFOPID has the best control performance and the strongest robustness under various operation conditions compared with other controller.

This paper is concerned to performance improvement of boost PFC converter under large random load fluctuation, ensuring unity power factor (UPF) at source end and regulated voltage at load side. To obtain such performance, a nonlinear controller based on dynamic evolution path theory is designed and its robustness is examined under both heavy and light loading condition. In this paper, %THD and zero-cross-over dead-zone of input current is significantly reduced. Also, very less response time of input current and output voltage to that of load and reference variation is remarked. A simulation model of proposed system is designed and it is realized using dSPACE 1104 signal processor for a 390V, 500W prototype. The relevant experimental and simulation waveforms are presented.Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.