An input-output signal selection based on Phillips-Heffron model of a parallel high voltage alternative current/high voltage direct current(HVAC/HVDC) power system is presented to study power system stability. It is w...An input-output signal selection based on Phillips-Heffron model of a parallel high voltage alternative current/high voltage direct current(HVAC/HVDC) power system is presented to study power system stability. It is well known that appropriate coupling of inputs-outputs signals in the multivariable HVDC-HVAC system can improve the performance of designed supplemetary controller. In this work, different analysis techniques are used to measure controllability and observability of electromechanical oscillation mode. Also inputs–outputs interactions are considered and suggestions are drawn to select the best signal pair through the system inputs-outputs. In addition, a supplementary online adaptive controller for nonlinear HVDC to damp low frequency oscillations in a weakly connected system is proposed. The results obtained using MATLAB software show that the best output-input for damping controller design is rotor speed deviation as out put and phase angle of rectifier as in put. Also response of system equipped with adaptive damping controller based on HVDC system has appropriate performance when it is faced with faults and disturbance.展开更多
A global fast terminal sliding mode(GFTSM)-based model predictive torque control(MPTC)strategy is developed for permanent magnet synchronous motor(PMSM)drive system with only one phase current sensor.Generally two pha...A global fast terminal sliding mode(GFTSM)-based model predictive torque control(MPTC)strategy is developed for permanent magnet synchronous motor(PMSM)drive system with only one phase current sensor.Generally two phase-current sensors are indispensable for MPTC.In response to only one phase current sensor available and the change of stator resistance,a novel adaptive observer for estimating the remaining two phase currents and time-varying stator resistance is proposed to perform MPTC.Moreover,in view of the variation of system parameters and external disturbance,a new GFTSM-based speed regulator is synthesized to enhance the drive system robustness.In this paper,the GFTSM,based on sliding mode theory,employs the fast terminal sliding mode in both the reaching stage and the sliding stage.The resultant GFTSM-based MPTC PMSM drive system with single phase current sensor has excellent dynamical performance which is very close to the GFTSM-based MPTC PMSM drive system with two-phase current sensors.On the other hand,compared with proportional-integral(PI)-based and sliding mode(SM)-based MPTC PMSM drive systems,it possesses better dynamical response and stronger robustness as well as smaller total harmonic distortion(THD)index of three-phase stator currents in the presence of variation of load torque.The simulation results validate the feasibility and effectiveness of the proposed scheme.展开更多
The vector control algorithm based on vector space decomposition （VSD） transformation method has a more flexible control freedom, which can control the fundamental and harmonic subspace separately. To this end, a cu...The vector control algorithm based on vector space decomposition （VSD） transformation method has a more flexible control freedom, which can control the fundamental and harmonic subspace separately. To this end, a current vector decoupling control algorithm for six-phase permanent magnet synchronous motor （PMSM） is designed. Using the proposed synchronous rotating coordinate transformation matrix, the fundamental and harmonic components in d-q subspace are changed into direct current （DC） component, only using the traditional proportional integral （PI） controller can meet the non-static difference adjustment, and the controller parameter design method is given by employing intemal model principle. In addition, in order to remove the 5th and 7th harmonic components of stator current, the current PI controller parallel with resonant controller is employed in x-y subspace to realize the specific harmonic component compensation. Simulation results verify the effectiveness of current decoupling vector controller.展开更多
在光储孤岛直流微电网中,需要最大化利用光伏发电,通常对光伏系统采用最大功率点跟踪(maximum power point tracking, MPPT)技术。但传统的MPPT控制速度慢、精度低,特别是在局部阴影情形下极易陷入局部最优解。基于此,首先提出一种将布...在光储孤岛直流微电网中,需要最大化利用光伏发电,通常对光伏系统采用最大功率点跟踪(maximum power point tracking, MPPT)技术。但传统的MPPT控制速度慢、精度低,特别是在局部阴影情形下极易陷入局部最优解。基于此,首先提出一种将布谷鸟搜索算法与电导增量法相结合的混合MPPT控制。利用布谷鸟搜索算法快速全局寻优,再使用电导增量法精确定位,实现快速而准确地跟踪最大功率点。储能单元是光储直流微电网的重要组成部分,其输出电流均分、荷电状态(stateof charge, SoC)均衡和直流母线电压稳定是主要控制目标。但电流均分受线路电阻差异的影响,进而影响SoC均衡和直流母线电压稳定,于是设计一种新的电压电流双环控制策略以实现上述目标。该策略在电压外环采用母线电压作为反馈值,在电流内环中设计了基于一致性算法的控制策略,将SoC与指数函数结合并引入加速因子,使得在充放电过程中实现SoC的快速均衡。所提控制策略既不需要下垂控制,也无需二次补偿控制,减轻了通信负担。最后在Matlab/Simulink中搭建直流微电网系统模型,验证所设计新的混合MPPT控制和电压电流双环控制策略的有效性。展开更多
文摘An input-output signal selection based on Phillips-Heffron model of a parallel high voltage alternative current/high voltage direct current(HVAC/HVDC) power system is presented to study power system stability. It is well known that appropriate coupling of inputs-outputs signals in the multivariable HVDC-HVAC system can improve the performance of designed supplemetary controller. In this work, different analysis techniques are used to measure controllability and observability of electromechanical oscillation mode. Also inputs–outputs interactions are considered and suggestions are drawn to select the best signal pair through the system inputs-outputs. In addition, a supplementary online adaptive controller for nonlinear HVDC to damp low frequency oscillations in a weakly connected system is proposed. The results obtained using MATLAB software show that the best output-input for damping controller design is rotor speed deviation as out put and phase angle of rectifier as in put. Also response of system equipped with adaptive damping controller based on HVDC system has appropriate performance when it is faced with faults and disturbance.
基金supported by the National Natural Science Foundation of China(61463025).
文摘A global fast terminal sliding mode(GFTSM)-based model predictive torque control(MPTC)strategy is developed for permanent magnet synchronous motor(PMSM)drive system with only one phase current sensor.Generally two phase-current sensors are indispensable for MPTC.In response to only one phase current sensor available and the change of stator resistance,a novel adaptive observer for estimating the remaining two phase currents and time-varying stator resistance is proposed to perform MPTC.Moreover,in view of the variation of system parameters and external disturbance,a new GFTSM-based speed regulator is synthesized to enhance the drive system robustness.In this paper,the GFTSM,based on sliding mode theory,employs the fast terminal sliding mode in both the reaching stage and the sliding stage.The resultant GFTSM-based MPTC PMSM drive system with single phase current sensor has excellent dynamical performance which is very close to the GFTSM-based MPTC PMSM drive system with two-phase current sensors.On the other hand,compared with proportional-integral(PI)-based and sliding mode(SM)-based MPTC PMSM drive systems,it possesses better dynamical response and stronger robustness as well as smaller total harmonic distortion(THD)index of three-phase stator currents in the presence of variation of load torque.The simulation results validate the feasibility and effectiveness of the proposed scheme.
基金Project(51507188)supported by the National Natural Science Foundation of China
文摘The vector control algorithm based on vector space decomposition （VSD） transformation method has a more flexible control freedom, which can control the fundamental and harmonic subspace separately. To this end, a current vector decoupling control algorithm for six-phase permanent magnet synchronous motor （PMSM） is designed. Using the proposed synchronous rotating coordinate transformation matrix, the fundamental and harmonic components in d-q subspace are changed into direct current （DC） component, only using the traditional proportional integral （PI） controller can meet the non-static difference adjustment, and the controller parameter design method is given by employing intemal model principle. In addition, in order to remove the 5th and 7th harmonic components of stator current, the current PI controller parallel with resonant controller is employed in x-y subspace to realize the specific harmonic component compensation. Simulation results verify the effectiveness of current decoupling vector controller.
文摘在光储孤岛直流微电网中,需要最大化利用光伏发电,通常对光伏系统采用最大功率点跟踪(maximum power point tracking, MPPT)技术。但传统的MPPT控制速度慢、精度低,特别是在局部阴影情形下极易陷入局部最优解。基于此,首先提出一种将布谷鸟搜索算法与电导增量法相结合的混合MPPT控制。利用布谷鸟搜索算法快速全局寻优,再使用电导增量法精确定位,实现快速而准确地跟踪最大功率点。储能单元是光储直流微电网的重要组成部分,其输出电流均分、荷电状态(stateof charge, SoC)均衡和直流母线电压稳定是主要控制目标。但电流均分受线路电阻差异的影响,进而影响SoC均衡和直流母线电压稳定,于是设计一种新的电压电流双环控制策略以实现上述目标。该策略在电压外环采用母线电压作为反馈值,在电流内环中设计了基于一致性算法的控制策略,将SoC与指数函数结合并引入加速因子,使得在充放电过程中实现SoC的快速均衡。所提控制策略既不需要下垂控制,也无需二次补偿控制,减轻了通信负担。最后在Matlab/Simulink中搭建直流微电网系统模型,验证所设计新的混合MPPT控制和电压电流双环控制策略的有效性。
