In predictive direct power control(PDPC)system of three-phase pulse width modulation(PWM)rectifier,grid voltage sensor makes the whole system more complex and costly.Therefore,third-order generalized integrator(TOGI)i...In predictive direct power control(PDPC)system of three-phase pulse width modulation(PWM)rectifier,grid voltage sensor makes the whole system more complex and costly.Therefore,third-order generalized integrator(TOGI)is used to generate orthogonal signals with the same frequency to estimate the grid voltage.In addition,in view of the deviation between actual and reference power in the three-phase PWM rectifier traditional PDPC strategy,a power correction link is designed to correct the power reference value.The grid voltage sensor free algorithm based on TOGI and the corrected PDPC strategy are applied to three-phase PWM rectifier and simulated on the simulation platform.Simulation results show that the proposed method can effectively eliminate the power tracking deviation and the grid voltage.The effectiveness of the proposed method is verified by comparing the simulation results.展开更多
Aiming at the PWM rectifier control strategy of sliding mode control, steady state performance weak Hamiltonian control dynamic tracking performance is poor, the coordinated compound control is proposed, the feedback ...Aiming at the PWM rectifier control strategy of sliding mode control, steady state performance weak Hamiltonian control dynamic tracking performance is poor, the coordinated compound control is proposed, the feedback linearization controller and sliding mode controller Hamiltonian system is obtained, and the design of a coordinated control strategy. In order to verify the accuracy of this method, MATLAB/Simulink is used for simulation analysis. The simulation results show that the composite control can achieve the coordinated dynamic rapid tracking and constant DC output and unit power factor operation, and satisfy the control requirements of the rectifier, effectively reducing the disturbance effect on the system. Compared with Hamiltonian control, the proposed method combines the advantages of the two methods, which have the fast tracking performance and excellent steady-state characteristics, and the research prospect is broad.展开更多
In the conventional cascade control structure of aerospace electrically powered actuators, the current（or electromagnetic torque） loop plays a critical role in realizing a rapid response for a digitally controlled B...In the conventional cascade control structure of aerospace electrically powered actuators, the current（or electromagnetic torque） loop plays a critical role in realizing a rapid response for a digitally controlled Brush Less Direct Current（BLDC） motor. Hysteresis Current Control（HCC） is an effective method in improving the performance of current control for a BLDC motor.Nevertheless, the varying modulating frequency in the traditional HCC causes severe problems on the safety of power devices and the electromagnetic compatibility design. A triangular carrier-based fixed-frequency HCC strategy is expanded by relaxing the constraints on the rising and descending rates of the winding current to advance the capability of HCC to realize fixed-frequency modulation in the steady state. Based on that, a new flexible-bound-size quasi-fixed-frequency HCC is proposed, and the range feasible to realize fixed-frequency modulation control can cover the entire running process in the steady state. Meanwhile, a corresponding digital control strategy is designed,and four digitalization rules are proposed to extend the capacity to achieve fixed-frequency modulation control to the unsteady working state, that is, a novel fixed-frequency modulation is realized.Simulation and experimental results prove the effectiveness of this improved fixed-frequency HCC strategy.展开更多
In this paper, a voltage oriented control strategy for three-level PWM rectifier based on Sliding Mode Control (SMC) is introduced in order to obtain fast and accurate response of dc-bus voltage. To verify the validit...In this paper, a voltage oriented control strategy for three-level PWM rectifier based on Sliding Mode Control (SMC) is introduced in order to obtain fast and accurate response of dc-bus voltage. To verify the validity of the analysis and the feasibility of the proposed control method a set of simulation tests have been conducted using Matlab/Simulink. The simulation results show that compared to the conventional PI controller, the SMC can reduce drastically the three-level rectifier’s voltage fluctuation and improve the dynamic response of dc-bus significantly.展开更多
To solve the problem of harmonic pollution to the power grid that caused by traditional diode rectifier and phase controlled rectifier, the unit power factor PWM rectifier is designed. The topology structure of the re...To solve the problem of harmonic pollution to the power grid that caused by traditional diode rectifier and phase controlled rectifier, the unit power factor PWM rectifier is designed. The topology structure of the rectifier circuit is introduced and the double closed-loop control strategy in three-phase stationary coordinate system is analyzed. For the deficiency of control strategy, the control strategy in two-phase synchronous rotating coordinate system is proposed. This makes the independent control of active current and reactive current to be realized. The simulation model of the PWM rectifier is built and the effectiveness of the control method proposed in this paper is verified by simulation.展开更多
Six-phase permanent magnet linear synchronous motor(PMLSM)for electromagnetic launch(EML)system presents the characteristics of a high order,nonlinearity,multivariable,strong coupling,and nonperiodic transient operati...Six-phase permanent magnet linear synchronous motor(PMLSM)for electromagnetic launch(EML)system presents the characteristics of a high order,nonlinearity,multivariable,strong coupling,and nonperiodic transient operation in the synchronous rotating coordinate system,posing a great challenge to the dynamic response ability of the current loop.Existing research on current decoupling control(CDC)mainly focuses on cross decoupling within a three-phase system,even though there are neither decoupling methods for multiphase systems nor effective evaluation criteria for the decoupling and dynamic response performances.From this perspective,this paper first presents an equivalent reduced-order complex-matrix dynamic mathematical model of six-phase PMLSM and analyze its transient coupling characteristics during the process of EML.Then,the CDC methods of six-phase PMLSM based on direct compensation and matrix diagonalization principles are realized,respectively,to accomplish the cross decoupling and back electromotive force decoupling within and between different three-phase windings.Finally,an all-round method is proposed,for the first time,to evaluate the decoupling performances and dynamic response performances of different CDC strategies for six-phase PMLSM.Significant superiority of deviation decoupling regulator in decoupling performance and robustness are verified based on high-speed EML experimental platform of six-phase PMLSM.展开更多
A control strategy of repetitive control without inductorance decoupling was proposed to address the problem of high total harmonic distortion(THD)rate of the network-side current caused by the reduced stability of th...A control strategy of repetitive control without inductorance decoupling was proposed to address the problem of high total harmonic distortion(THD)rate of the network-side current caused by the reduced stability of the rectifier module of the DC charging pile under weak grid as well as the dead zone and nonlinearity of switching devices during charging.Firstly,the parallel repetitive control was constructed in the inner current loop,and the proportional-integral(PI)+repetitive controller based on parallel structure was designed.For system compensation,a second-order low-pass filter was selected to correct the system,and the network-side current harmonics were actively suppressed without increasing the filtering device,which effectively improves the quality of grid-connected current.Secondly,based on the synthetic vector method,the controller parameters were designed to realize the elimination of main pole by establishing two synchronous rotation coordinate system vector differential equations,so as to realize the inductanceless decoupling to cope with the influence of network-side inductance fluctuation on the stability of the control system under weak grid.By theoretical analysis and simulation,the proposed control strategy was embedded into the self-developed digital signal processor for the rectifier module of DC charging pile,simulated dynamic and steady-state operation experiments were conducted,and comparative analysis was performed to prove the feasibility of the proposed control strategy.展开更多
This paper proposes a novel multi-pulse flexible-topology thyristor rectifier(FTTR) that can operate over a large voltage range while maintaining a low total harmonic distortion(THD) in the input current.The proposed ...This paper proposes a novel multi-pulse flexible-topology thyristor rectifier(FTTR) that can operate over a large voltage range while maintaining a low total harmonic distortion(THD) in the input current.The proposed multi-pulse FTTR has two operating modes:parallel mode and series mode.Irrespective of the mode in which it operates,the multi-pulse FTTR maintains the same pulses in the load current.To mitigate the harmonic injection into the AC mains,the topology-switching mechanism is then proposed.In addition,predictive current control is employed to achieve fast current response in both the transience and the transitions between modes.To verify the effectiveness of the multi-pulse FTTR as well as the control scheme,performance analysis based on an 18-pulse FTTR is investigated in detail,including fault tolerance evaluation,current THD analysis based on IEEE standard,and potential applications.Finally,a simulation model and the corresponding laboratory setup are developed.The results from both simulation and experiments demonstrate the feasibility of the proposed multi-pulse FTTR as well as the control scheme.展开更多
The performance of the current stabilization control system in an aluminum smelter affects the quality and the quantity of the electrolytic products. This paper elaborates the power supply, in which the diode rectifie...The performance of the current stabilization control system in an aluminum smelter affects the quality and the quantity of the electrolytic products. This paper elaborates the power supply, in which the diode rectifiers and the self-saturable reactors could keep the series current stable, then describes the basic principle of the rectifier unit control and the series current control. A coordinate strategy is proposed to keep the series current stable, the self-saturable reactors are controlled by a proportional-integral control scheme and the on load tap changers of transformer are triggered by the errors between the setting value of the series voltage and the measured values of the series voltage. Simulation results on PSCAD/EMTDC show that the effectiveness of the proposed strategy to keep the series current stable.展开更多
A diode-triggered silicon controlled rectifier (DTSCR) is being developed as an electrostatic discharge (ESD) pro- tection device for low voltage applications. However, DTSCR leaks high current during normal operation...A diode-triggered silicon controlled rectifier (DTSCR) is being developed as an electrostatic discharge (ESD) pro- tection device for low voltage applications. However, DTSCR leaks high current during normal operation due to the Darlington effect of the triggering-assist diode string. In this study, two types of diode string triggered SCRs are designed for low leakage consideration; the modified diode string and composite polysilicon diode string triggered SCRs (MDTSCR & PDTSCR). Com- pared with the conventional DTSCR (CDTSCR), the MDTSCR has a much lower substrate leakage current with a relatively large silicon cost, and the PDTSCR has a much lower substrate leakage current with similar area and shows good leakage performance at a high temperature. Other DTSCR ESD properties are also investigated, especially regarding their layout, triggering voltage and failure current.展开更多
In this paper, a new current-controlled-power technique for small signal applications is presented. The proposed technique needs no passive devices (a resistor and a capacitor) but the well-known SCR technique needs, ...In this paper, a new current-controlled-power technique for small signal applications is presented. The proposed technique needs no passive devices (a resistor and a capacitor) but the well-known SCR technique needs, thus the proposed technique is very suitable for an IC process. An example application as a new current-controlled-power CMOS fullwave rectifier is also given. The example application is simulated by using the SPICE program. Simulation results show that the proposed technique can work well;the controlled-current from 0 μA to 5.5 μA produces the peak area amplitude from 100 mV to 0 mV to the load.展开更多
基金National Natural Science Foundation of China(Nos.51767013,52067013)。
文摘In predictive direct power control(PDPC)system of three-phase pulse width modulation(PWM)rectifier,grid voltage sensor makes the whole system more complex and costly.Therefore,third-order generalized integrator(TOGI)is used to generate orthogonal signals with the same frequency to estimate the grid voltage.In addition,in view of the deviation between actual and reference power in the three-phase PWM rectifier traditional PDPC strategy,a power correction link is designed to correct the power reference value.The grid voltage sensor free algorithm based on TOGI and the corrected PDPC strategy are applied to three-phase PWM rectifier and simulated on the simulation platform.Simulation results show that the proposed method can effectively eliminate the power tracking deviation and the grid voltage.The effectiveness of the proposed method is verified by comparing the simulation results.
文摘Aiming at the PWM rectifier control strategy of sliding mode control, steady state performance weak Hamiltonian control dynamic tracking performance is poor, the coordinated compound control is proposed, the feedback linearization controller and sliding mode controller Hamiltonian system is obtained, and the design of a coordinated control strategy. In order to verify the accuracy of this method, MATLAB/Simulink is used for simulation analysis. The simulation results show that the composite control can achieve the coordinated dynamic rapid tracking and constant DC output and unit power factor operation, and satisfy the control requirements of the rectifier, effectively reducing the disturbance effect on the system. Compared with Hamiltonian control, the proposed method combines the advantages of the two methods, which have the fast tracking performance and excellent steady-state characteristics, and the research prospect is broad.
基金supported by the National Natural Science Foundation of China (Nos.51275021,61327807)
文摘In the conventional cascade control structure of aerospace electrically powered actuators, the current（or electromagnetic torque） loop plays a critical role in realizing a rapid response for a digitally controlled Brush Less Direct Current（BLDC） motor. Hysteresis Current Control（HCC） is an effective method in improving the performance of current control for a BLDC motor.Nevertheless, the varying modulating frequency in the traditional HCC causes severe problems on the safety of power devices and the electromagnetic compatibility design. A triangular carrier-based fixed-frequency HCC strategy is expanded by relaxing the constraints on the rising and descending rates of the winding current to advance the capability of HCC to realize fixed-frequency modulation in the steady state. Based on that, a new flexible-bound-size quasi-fixed-frequency HCC is proposed, and the range feasible to realize fixed-frequency modulation control can cover the entire running process in the steady state. Meanwhile, a corresponding digital control strategy is designed,and four digitalization rules are proposed to extend the capacity to achieve fixed-frequency modulation control to the unsteady working state, that is, a novel fixed-frequency modulation is realized.Simulation and experimental results prove the effectiveness of this improved fixed-frequency HCC strategy.
文摘In this paper, a voltage oriented control strategy for three-level PWM rectifier based on Sliding Mode Control (SMC) is introduced in order to obtain fast and accurate response of dc-bus voltage. To verify the validity of the analysis and the feasibility of the proposed control method a set of simulation tests have been conducted using Matlab/Simulink. The simulation results show that compared to the conventional PI controller, the SMC can reduce drastically the three-level rectifier’s voltage fluctuation and improve the dynamic response of dc-bus significantly.
文摘To solve the problem of harmonic pollution to the power grid that caused by traditional diode rectifier and phase controlled rectifier, the unit power factor PWM rectifier is designed. The topology structure of the rectifier circuit is introduced and the double closed-loop control strategy in three-phase stationary coordinate system is analyzed. For the deficiency of control strategy, the control strategy in two-phase synchronous rotating coordinate system is proposed. This makes the independent control of active current and reactive current to be realized. The simulation model of the PWM rectifier is built and the effectiveness of the control method proposed in this paper is verified by simulation.
基金This study was supported by the National Natural Science Foundation of China(No.52077219).
文摘Six-phase permanent magnet linear synchronous motor(PMLSM)for electromagnetic launch(EML)system presents the characteristics of a high order,nonlinearity,multivariable,strong coupling,and nonperiodic transient operation in the synchronous rotating coordinate system,posing a great challenge to the dynamic response ability of the current loop.Existing research on current decoupling control(CDC)mainly focuses on cross decoupling within a three-phase system,even though there are neither decoupling methods for multiphase systems nor effective evaluation criteria for the decoupling and dynamic response performances.From this perspective,this paper first presents an equivalent reduced-order complex-matrix dynamic mathematical model of six-phase PMLSM and analyze its transient coupling characteristics during the process of EML.Then,the CDC methods of six-phase PMLSM based on direct compensation and matrix diagonalization principles are realized,respectively,to accomplish the cross decoupling and back electromotive force decoupling within and between different three-phase windings.Finally,an all-round method is proposed,for the first time,to evaluate the decoupling performances and dynamic response performances of different CDC strategies for six-phase PMLSM.Significant superiority of deviation decoupling regulator in decoupling performance and robustness are verified based on high-speed EML experimental platform of six-phase PMLSM.
基金supported by National Natural Science Foundation of China(No.61903291)Shaanxi Province Key R&D Program(No.2022GY-134)。
文摘A control strategy of repetitive control without inductorance decoupling was proposed to address the problem of high total harmonic distortion(THD)rate of the network-side current caused by the reduced stability of the rectifier module of the DC charging pile under weak grid as well as the dead zone and nonlinearity of switching devices during charging.Firstly,the parallel repetitive control was constructed in the inner current loop,and the proportional-integral(PI)+repetitive controller based on parallel structure was designed.For system compensation,a second-order low-pass filter was selected to correct the system,and the network-side current harmonics were actively suppressed without increasing the filtering device,which effectively improves the quality of grid-connected current.Secondly,based on the synthetic vector method,the controller parameters were designed to realize the elimination of main pole by establishing two synchronous rotation coordinate system vector differential equations,so as to realize the inductanceless decoupling to cope with the influence of network-side inductance fluctuation on the stability of the control system under weak grid.By theoretical analysis and simulation,the proposed control strategy was embedded into the self-developed digital signal processor for the rectifier module of DC charging pile,simulated dynamic and steady-state operation experiments were conducted,and comparative analysis was performed to prove the feasibility of the proposed control strategy.
基金Project supported by the National Natural Science Foundation of China (No. 51177148)the Zhejiang Key Science and Technology Innovation Group Program,China (No. 2010R50021)
文摘This paper proposes a novel multi-pulse flexible-topology thyristor rectifier(FTTR) that can operate over a large voltage range while maintaining a low total harmonic distortion(THD) in the input current.The proposed multi-pulse FTTR has two operating modes:parallel mode and series mode.Irrespective of the mode in which it operates,the multi-pulse FTTR maintains the same pulses in the load current.To mitigate the harmonic injection into the AC mains,the topology-switching mechanism is then proposed.In addition,predictive current control is employed to achieve fast current response in both the transience and the transitions between modes.To verify the effectiveness of the multi-pulse FTTR as well as the control scheme,performance analysis based on an 18-pulse FTTR is investigated in detail,including fault tolerance evaluation,current THD analysis based on IEEE standard,and potential applications.Finally,a simulation model and the corresponding laboratory setup are developed.The results from both simulation and experiments demonstrate the feasibility of the proposed multi-pulse FTTR as well as the control scheme.
文摘The performance of the current stabilization control system in an aluminum smelter affects the quality and the quantity of the electrolytic products. This paper elaborates the power supply, in which the diode rectifiers and the self-saturable reactors could keep the series current stable, then describes the basic principle of the rectifier unit control and the series current control. A coordinate strategy is proposed to keep the series current stable, the self-saturable reactors are controlled by a proportional-integral control scheme and the on load tap changers of transformer are triggered by the errors between the setting value of the series voltage and the measured values of the series voltage. Simulation results on PSCAD/EMTDC show that the effectiveness of the proposed strategy to keep the series current stable.
基金Project partially supported by the Zhejiang Provincial Nature Science Fund of China (Nos. Y107055 and Y1080546)the Semiconductor Manufacturing International Corp. (SMIC)
文摘A diode-triggered silicon controlled rectifier (DTSCR) is being developed as an electrostatic discharge (ESD) pro- tection device for low voltage applications. However, DTSCR leaks high current during normal operation due to the Darlington effect of the triggering-assist diode string. In this study, two types of diode string triggered SCRs are designed for low leakage consideration; the modified diode string and composite polysilicon diode string triggered SCRs (MDTSCR & PDTSCR). Com- pared with the conventional DTSCR (CDTSCR), the MDTSCR has a much lower substrate leakage current with a relatively large silicon cost, and the PDTSCR has a much lower substrate leakage current with similar area and shows good leakage performance at a high temperature. Other DTSCR ESD properties are also investigated, especially regarding their layout, triggering voltage and failure current.
文摘In this paper, a new current-controlled-power technique for small signal applications is presented. The proposed technique needs no passive devices (a resistor and a capacitor) but the well-known SCR technique needs, thus the proposed technique is very suitable for an IC process. An example application as a new current-controlled-power CMOS fullwave rectifier is also given. The example application is simulated by using the SPICE program. Simulation results show that the proposed technique can work well;the controlled-current from 0 μA to 5.5 μA produces the peak area amplitude from 100 mV to 0 mV to the load.
