Signal filtering and differential acquisition are classic yet challenging issues in control engineering.The discrete-time optimal control(DTOC)based on classic tracking differentiator(TD)can effectively extract differ...Signal filtering and differential acquisition are classic yet challenging issues in control engineering.The discrete-time optimal control(DTOC)based on classic tracking differentiator(TD)can effectively extract differentiation signals and filter signals,while eliminating the chattering problem that arises during the discretization of the continuous solution.However,under external disturbance,the convergence mode may change,leading to overshoot and noise amplification.In this paper,a dual-switching strategy is proposed,which can alternate between the base double-integral system and its dual system according to the quadrant of the system’s state.And a novel linearized control law is also introduced,deriving a novel dual-switch tracking differentiator.Further analysis of system convergence and time optimality is provided.Simulation results show that the application of this dual-switching strategy notably reduces overshoot in both tracking and differential signals while enhancing noise filtering performance.Moreover,experiments conducted on a permanent magnet synchronous motor(PMSM)platform,where the proposed TD acts as a filter in the speed feedback loop,demonstrate that the standard deviation between the reference speed and the target speed(at a constant speed of 378 r/min)decreased from 5.63 r/min to 4.93 r/min,compared to the moving average algorithm.展开更多
针对双有源桥(dual active bridge,DAB)电路在电动汽车充放电能量转换过程中存在的传输效率低的问题,文中提出一种结合微分极值法与分段控制的最小电流应力优化控制策略。该策略在满足软开关约束的前提下,优化电流应力与抑制回流功率,...针对双有源桥(dual active bridge,DAB)电路在电动汽车充放电能量转换过程中存在的传输效率低的问题,文中提出一种结合微分极值法与分段控制的最小电流应力优化控制策略。该策略在满足软开关约束的前提下,优化电流应力与抑制回流功率,从而有效提升传输效率。首先,以功率正向传输为例,推导拓展移相(extended phase shift,EPS)控制在两种工作模态下实现开关管软开关的条件,并分析回流功率的产生机理,阐述减小电流应力对抑制回流功率的作用;然后,基于微分极值法推导最小电流应力的最优移相比组合,并结合不同模态下软开关范围进行分段控制;最后,实验结果表明,在电压传输比大于1时,该最小电流应力优化策略在全功率范围内实现所有开关管软开关的同时,可以有效降低电流应力、抑制回流功率、提升传输效率。在电压传输比小于1时,该策略虽仍可降低电流应力,但并不能实现所有开关管零电压开通。展开更多
目前水下无线电能传输(wireless power transfer,WPT)系统电池负载端电压等级较低,为有效提升功率密度及直流电压利用率,同时降低高频逆变环节电压电流应力,最为有效的方式是在系统初级引入高频降压式直流变换环节。为此,本文在系统初...目前水下无线电能传输(wireless power transfer,WPT)系统电池负载端电压等级较低,为有效提升功率密度及直流电压利用率,同时降低高频逆变环节电压电流应力,最为有效的方式是在系统初级引入高频降压式直流变换环节。为此,本文在系统初级引入隔离型高频双管正激变换器,考虑到传统稳定性分析方法的局限性,拟采用适用于高频系统的模值分析法对直流变换器动态特征展开分析。仿真与实验结果表明,该方法可使水下WPT系统初级直流变换器稳定性能得到显著提升,具有一定的工程应用价值。展开更多
随着双有源桥开关频率的不断提高,开关损耗在总损耗中的占比逐渐增大。零电压开关(zero voltage switching,ZVS)控制策略已成为降低开关损耗的主要手段。然而,传统ZVS控制策略在考虑死区时间时,存在ZVS区域不连续和移相比突变的问题,影...随着双有源桥开关频率的不断提高,开关损耗在总损耗中的占比逐渐增大。零电压开关(zero voltage switching,ZVS)控制策略已成为降低开关损耗的主要手段。然而,传统ZVS控制策略在考虑死区时间时,存在ZVS区域不连续和移相比突变的问题,影响系统稳定。为了解决该问题,提出一种在全功率范围内移相比非突变的ZVS和电流应力优化策略。在中等功率范围内,由于死区时间的影响,所有开关器件的ZVS无法完全实现,以牺牲第1个桥臂开关器件的ZVS为代价,确保移相比的连续变化。在高功率范围内,以移相比连续变化为目标,重新调整分界线,实现中等功率范围与高功率范围的无缝切换。理论分析表明,提出的优化策略能够在全功率范围内保证移相比的连续性。通过搭建小功率实验平台,实验结果验证了所提优化策略的正确性和有效性。展开更多
基金Project(QZKFKT2023-012)supported by the State Key Laboratory of Heavy-duty and Express High-power Electric Locomotive,China。
文摘Signal filtering and differential acquisition are classic yet challenging issues in control engineering.The discrete-time optimal control(DTOC)based on classic tracking differentiator(TD)can effectively extract differentiation signals and filter signals,while eliminating the chattering problem that arises during the discretization of the continuous solution.However,under external disturbance,the convergence mode may change,leading to overshoot and noise amplification.In this paper,a dual-switching strategy is proposed,which can alternate between the base double-integral system and its dual system according to the quadrant of the system’s state.And a novel linearized control law is also introduced,deriving a novel dual-switch tracking differentiator.Further analysis of system convergence and time optimality is provided.Simulation results show that the application of this dual-switching strategy notably reduces overshoot in both tracking and differential signals while enhancing noise filtering performance.Moreover,experiments conducted on a permanent magnet synchronous motor(PMSM)platform,where the proposed TD acts as a filter in the speed feedback loop,demonstrate that the standard deviation between the reference speed and the target speed(at a constant speed of 378 r/min)decreased from 5.63 r/min to 4.93 r/min,compared to the moving average algorithm.
文摘针对双有源桥(dual active bridge,DAB)电路在电动汽车充放电能量转换过程中存在的传输效率低的问题,文中提出一种结合微分极值法与分段控制的最小电流应力优化控制策略。该策略在满足软开关约束的前提下,优化电流应力与抑制回流功率,从而有效提升传输效率。首先,以功率正向传输为例,推导拓展移相(extended phase shift,EPS)控制在两种工作模态下实现开关管软开关的条件,并分析回流功率的产生机理,阐述减小电流应力对抑制回流功率的作用;然后,基于微分极值法推导最小电流应力的最优移相比组合,并结合不同模态下软开关范围进行分段控制;最后,实验结果表明,在电压传输比大于1时,该最小电流应力优化策略在全功率范围内实现所有开关管软开关的同时,可以有效降低电流应力、抑制回流功率、提升传输效率。在电压传输比小于1时,该策略虽仍可降低电流应力,但并不能实现所有开关管零电压开通。
文摘目前水下无线电能传输(wireless power transfer,WPT)系统电池负载端电压等级较低,为有效提升功率密度及直流电压利用率,同时降低高频逆变环节电压电流应力,最为有效的方式是在系统初级引入高频降压式直流变换环节。为此,本文在系统初级引入隔离型高频双管正激变换器,考虑到传统稳定性分析方法的局限性,拟采用适用于高频系统的模值分析法对直流变换器动态特征展开分析。仿真与实验结果表明,该方法可使水下WPT系统初级直流变换器稳定性能得到显著提升,具有一定的工程应用价值。
文摘随着双有源桥开关频率的不断提高,开关损耗在总损耗中的占比逐渐增大。零电压开关(zero voltage switching,ZVS)控制策略已成为降低开关损耗的主要手段。然而,传统ZVS控制策略在考虑死区时间时,存在ZVS区域不连续和移相比突变的问题,影响系统稳定。为了解决该问题,提出一种在全功率范围内移相比非突变的ZVS和电流应力优化策略。在中等功率范围内,由于死区时间的影响,所有开关器件的ZVS无法完全实现,以牺牲第1个桥臂开关器件的ZVS为代价,确保移相比的连续变化。在高功率范围内,以移相比连续变化为目标,重新调整分界线,实现中等功率范围与高功率范围的无缝切换。理论分析表明,提出的优化策略能够在全功率范围内保证移相比的连续性。通过搭建小功率实验平台,实验结果验证了所提优化策略的正确性和有效性。
