模块间接地故障是H桥级联型电池储能系统(cascaded H bridge based battery energy storage system,CHB-BESS)的易发故障,快速诊断故障位置对减少故障损失至关重要。模块间接地故障的故障特征主要体现在零序电流上,会受到接地过渡电阻...模块间接地故障是H桥级联型电池储能系统(cascaded H bridge based battery energy storage system,CHB-BESS)的易发故障,快速诊断故障位置对减少故障损失至关重要。模块间接地故障的故障特征主要体现在零序电流上,会受到接地过渡电阻的影响。为实现接地过渡电阻不确定情况下,故障模块位置的快速准确鲁棒定位,本工作提出了一种基于损失特征矩阵的快速故障诊断方法。首先,本工作建立了零序等效电路模型;然后,将零序电流模型离散化;接着,提出基于损失特征矩阵的定位方法,该方法使用拓扑矩阵描述故障位置和过渡电阻的遍历信息,基于离散化模型来遍历计算零序电流,将计算结果与测量结果的偏差记录在损失特征矩阵中,通过偏差最优解确定故障位置;其次,本工作证实了故障定位问题作为最优化问题具有最优解唯一性,偏差最优解在接地过渡电阻不确定的情况下可获得准确的故障发生位置;最终,基于最优解唯一性提出了最优化计算的加速方法。实测表明,所提方法的平均定位误差仅为0.2个子模块,在接地过渡电阻较大范围不确定的情况下实现了准确定位,并且所提加速方法显著提高诊断速度。展开更多
Battery energy storage systems(BESSs)are widely used in smart grids.However,power consumed by inner impedance and the capacity degradation of each battery unit become particularly severe,which has resulted in an incre...Battery energy storage systems(BESSs)are widely used in smart grids.However,power consumed by inner impedance and the capacity degradation of each battery unit become particularly severe,which has resulted in an increase in operating costs.The general economic dispatch(ED)algorithm based on marginal cost(MC)consensus is usually a proportional(P)controller,which encounters the defects of slow convergence speed and low control accuracy.In order to solve the distributed ED problem of the isolated BESS network with excellent dynamic and steady-state performance,we attempt to design a proportional integral(PI)controller with a reset mechanism(PI+R)to asymptotically promote MC consensus and total power mismatch towards 0 in this paper.To be frank,the integral term in the PI controller is reset to 0 at an appropriate time when the proportional term undergoes a zero crossing,which accelerates convergence,improves control accuracy,and avoids overshoot.The eigenvalues of the system under a PI+R controller is well analyzed,ensuring the regularity of the system and enabling the reset mechanism.To ensure supply and demand balance within the isolated BESSs,a centralized reset mechanism is introduced,so that the controller is distributed in a flow set and centralized in a jump set.To cope with Zeno behavior and input delay,a dwell time that the system resides in a flow set is given.Based on this,the system with input delays can be reduced to a time-delay free system.Considering the capacity limitation of the battery,a modified MC scheme with PI+R controller is designed.The correctness of the designed scheme is verified through relevant simulations.展开更多
When large-scale distributed renewable energy power generation systems are connected to the power grid,the risk of grid voltage fluctuations and exceeding the limit increases greatly.Fortunately,the on-load tap change...When large-scale distributed renewable energy power generation systems are connected to the power grid,the risk of grid voltage fluctuations and exceeding the limit increases greatly.Fortunately,the on-load tap changer(OLTC)can adjust the transformer winding tap to maintain the secondary side voltage within the normal range.However,the inevitable delay in switching transformer taps makes it difficult to respond quickly to voltage fluctuations.Moreover,switching the transformer taps frequently will decrease the service life of OLTC.In order to solve this critical issue,a cooperative voltage regulation strategy applied between the battery energy storage systems(BESSs)and OLTSs.is proposed By adjusting the charge and discharge power of BESSs,the OLTC can frequently switch the transformer taps to achieve rapid voltage regulation.The effectiveness of the proposed coordinated regulation strategy is verified in the IEEE 33 node distribution systems.The simulation results show that the proposed coordinated regulation strategy can stabilize the voltage of the distribution network within a normal range and reduce the frequency of tap switching,as such elongating the service life of the equipment.展开更多
针对海上风电场交流传输行为控制效果不理想的问题,提出了海上风电场中BESS(Battery energy storage system)与SVG(Static var generator)并联补偿控制策略。对海上风电场中的电量循环特性进行了分析,按照静止同步补偿器闭环、载波移相...针对海上风电场交流传输行为控制效果不理想的问题,提出了海上风电场中BESS(Battery energy storage system)与SVG(Static var generator)并联补偿控制策略。对海上风电场中的电量循环特性进行了分析,按照静止同步补偿器闭环、载波移相调制技术的实施标准,构建瞬时功率指标与负序补偿原则,实现了BESS补偿控制机制、SVG补偿控制机制的研究。在优先级参量的约束下,确定BESS与SVG机制之间的并联作用关系,完成海上风电场中BESS与SVG并联补偿控制。实验结果表明,在BESS与SVG并联优先补偿方法的作用下,电流谐波振荡幅度被控制在-5.25~5.25 A区间之内,与电源协同型控制策略相比,更符合交变电流传输行为有效控制的需求。展开更多
带蓄电池储能装置的静止同步补偿器(STATCOM/BESS)在解决快速补偿系统所需要的有功功率和无功功率、灵活平抑新能源发电引起的供电波动等问题中是非常重要的装备。直接功率控制(Direct Power Control,DPC)是瞬时功率理论的另一种表现形...带蓄电池储能装置的静止同步补偿器(STATCOM/BESS)在解决快速补偿系统所需要的有功功率和无功功率、灵活平抑新能源发电引起的供电波动等问题中是非常重要的装备。直接功率控制(Direct Power Control,DPC)是瞬时功率理论的另一种表现形式,它无需借助其他变量,对有功功率和无功功率直接进行控制。文章主要对STATCOM/BESS装置DPC控制策略和控制算法进行了理论分析,并将DPC控制策略及基于空间矢量调制的直接功率控制策略(Direct power control with space vector modulation,DPC-SVM)运用到系统中,在Matlab/Simulink中进行仿真分析。展开更多
文摘模块间接地故障是H桥级联型电池储能系统(cascaded H bridge based battery energy storage system,CHB-BESS)的易发故障,快速诊断故障位置对减少故障损失至关重要。模块间接地故障的故障特征主要体现在零序电流上,会受到接地过渡电阻的影响。为实现接地过渡电阻不确定情况下,故障模块位置的快速准确鲁棒定位,本工作提出了一种基于损失特征矩阵的快速故障诊断方法。首先,本工作建立了零序等效电路模型;然后,将零序电流模型离散化;接着,提出基于损失特征矩阵的定位方法,该方法使用拓扑矩阵描述故障位置和过渡电阻的遍历信息,基于离散化模型来遍历计算零序电流,将计算结果与测量结果的偏差记录在损失特征矩阵中,通过偏差最优解确定故障位置;其次,本工作证实了故障定位问题作为最优化问题具有最优解唯一性,偏差最优解在接地过渡电阻不确定的情况下可获得准确的故障发生位置;最终,基于最优解唯一性提出了最优化计算的加速方法。实测表明,所提方法的平均定位误差仅为0.2个子模块,在接地过渡电阻较大范围不确定的情况下实现了准确定位,并且所提加速方法显著提高诊断速度。
基金supported by the National Natural Science Foundation of China(62103203)the General Terminal IC Interdisciplinary Science Center of Nankai University.
文摘Battery energy storage systems(BESSs)are widely used in smart grids.However,power consumed by inner impedance and the capacity degradation of each battery unit become particularly severe,which has resulted in an increase in operating costs.The general economic dispatch(ED)algorithm based on marginal cost(MC)consensus is usually a proportional(P)controller,which encounters the defects of slow convergence speed and low control accuracy.In order to solve the distributed ED problem of the isolated BESS network with excellent dynamic and steady-state performance,we attempt to design a proportional integral(PI)controller with a reset mechanism(PI+R)to asymptotically promote MC consensus and total power mismatch towards 0 in this paper.To be frank,the integral term in the PI controller is reset to 0 at an appropriate time when the proportional term undergoes a zero crossing,which accelerates convergence,improves control accuracy,and avoids overshoot.The eigenvalues of the system under a PI+R controller is well analyzed,ensuring the regularity of the system and enabling the reset mechanism.To ensure supply and demand balance within the isolated BESSs,a centralized reset mechanism is introduced,so that the controller is distributed in a flow set and centralized in a jump set.To cope with Zeno behavior and input delay,a dwell time that the system resides in a flow set is given.Based on this,the system with input delays can be reduced to a time-delay free system.Considering the capacity limitation of the battery,a modified MC scheme with PI+R controller is designed.The correctness of the designed scheme is verified through relevant simulations.
基金Supported by the Postdoctoral Science Foundation of China(No.2022M710039)。
文摘When large-scale distributed renewable energy power generation systems are connected to the power grid,the risk of grid voltage fluctuations and exceeding the limit increases greatly.Fortunately,the on-load tap changer(OLTC)can adjust the transformer winding tap to maintain the secondary side voltage within the normal range.However,the inevitable delay in switching transformer taps makes it difficult to respond quickly to voltage fluctuations.Moreover,switching the transformer taps frequently will decrease the service life of OLTC.In order to solve this critical issue,a cooperative voltage regulation strategy applied between the battery energy storage systems(BESSs)and OLTSs.is proposed By adjusting the charge and discharge power of BESSs,the OLTC can frequently switch the transformer taps to achieve rapid voltage regulation.The effectiveness of the proposed coordinated regulation strategy is verified in the IEEE 33 node distribution systems.The simulation results show that the proposed coordinated regulation strategy can stabilize the voltage of the distribution network within a normal range and reduce the frequency of tap switching,as such elongating the service life of the equipment.
文摘针对海上风电场交流传输行为控制效果不理想的问题,提出了海上风电场中BESS(Battery energy storage system)与SVG(Static var generator)并联补偿控制策略。对海上风电场中的电量循环特性进行了分析,按照静止同步补偿器闭环、载波移相调制技术的实施标准,构建瞬时功率指标与负序补偿原则,实现了BESS补偿控制机制、SVG补偿控制机制的研究。在优先级参量的约束下,确定BESS与SVG机制之间的并联作用关系,完成海上风电场中BESS与SVG并联补偿控制。实验结果表明,在BESS与SVG并联优先补偿方法的作用下,电流谐波振荡幅度被控制在-5.25~5.25 A区间之内,与电源协同型控制策略相比,更符合交变电流传输行为有效控制的需求。
文摘带蓄电池储能装置的静止同步补偿器(STATCOM/BESS)在解决快速补偿系统所需要的有功功率和无功功率、灵活平抑新能源发电引起的供电波动等问题中是非常重要的装备。直接功率控制(Direct Power Control,DPC)是瞬时功率理论的另一种表现形式,它无需借助其他变量,对有功功率和无功功率直接进行控制。文章主要对STATCOM/BESS装置DPC控制策略和控制算法进行了理论分析,并将DPC控制策略及基于空间矢量调制的直接功率控制策略(Direct power control with space vector modulation,DPC-SVM)运用到系统中,在Matlab/Simulink中进行仿真分析。
