Design of Controller for New EAST Fast Control Power Supply

The effectiveness of the magnetic confinement of plasma can be improved by elongat- ing the plasma cross-section in tokamak devices. But elongated plasma has vertical displacement instability, so a feedback control system is needed to restrain the plasma＇s vertical displacement. A fast control power supply is needed to excite the active feedback coils, which produces a magnetic field to control the plasma＇s displacement. With the development of EAST, the fast control power supply needs to keep on enhancing the fast response and output current. The structure of a new power supply is introduced in this paper. The method of multiple inverters paralleled with the current sharing reactor is presented to meet the need for large current and fast control. According to the design demands of the EAST fast control power supply, the adjuster of the current close loop is applied to the inverter, which can advance its ability to restrain the loop current in low frequency and DC output. The result of the experiment confirms the validity of the proposed scheme and control strategy.

Application of a Current and Voltage Mixed Control Mode for the New Fast Control Power Supply at EAST

A feedback control system is needed to restrain plasma vertical displacement in EAST （Experimental Advanced Superconducting Toknmak）. A fast control power supply excites active feedback coils, which produces a magnetic field to control the plasma＇s displacement. With the development of EAST, new demands on the new fast control power supply have led to an enhanced ability of fast response and output current, as well as a new control mode. The structure of cascaded and paralleled H-bridges can meet the demand of extended capacity, and digital control can reMize current and voltage mixed control mode. The validity of the proposed scheme is confirmed by experiments.

Addressing Frequency Control Challenges in Future Low-Inertia Power Systems:A Great Britain Perspective

The ambitious global targets on decarbonization present the need for massive integration of renewable generation in power systems,resulting in a significant decrease in the system inertia.In addition to the reduction in system inertia,the transmission system in Great Britain(GB)faces some unique challenges owing to its relatively small capacity,while being decoupled from other transmission systems and with the renewable resources largely non-uniformly distributed across the system.This paper presents opinions and insights on the challenges associated with frequency control in a low-inertia system and the potential solutions from a GB perspective.In this paper,we focus on three main techniques that act over different time scales:synchronous condensers,inertia emulation,and fast frequency response.We evaluate their relative advantages and limitations with learnings from recent research and development projects in GB,along with the opinions on their roles in addressing the frequency control challenges in future low-inertia systems.

Generalized reduced-order synchronization of chaotic system based on fast slide mode

A new kind of generalized reduced-order synchronization of different chaotic systems is proposed in this paper. It is shown that dynamical evolution of third-order oscillator can be synchronized with the canonical projection of a fourth-order chaotic system generated through nonsingular states transformation from a cell neural net chaotic system. In this sense, it is said that generalized synchronization is achieved in reduced-order. The synchronization discussed here expands the scope of reduced-order synchronization studied in relevant literatures. In this way, we can achieve generalized reduced-order synchronization between many famous chaotic systems such as the second-order Drifting system and the third-order Lorenz system by designing a fast slide mode controller. Simulation results are provided to verify the operation of the designed synchronization.

A Bio-Inspired Global Finite Time Tracking Control of Four-Rotor Test Bench System

A bio-inspired global finite time control using global fast-terminal sliding mode controller and radial basis function network is presented in this article,to address the attitude tracking control problem of the three degree-of-freedom four-rotor hover system.The proposed controller provides convergence of system states in a predetermined finite time and estimates the unmodeled dynamics of the four-rotor system.Dynamic model of the four-rotor system is derived with Newton’s force equations.The unknown dynamics of four-rotor systems are estimated using Radial basis function.The bio-inspired global fast terminal sliding mode controller is proposed to provide chattering free finite time error convergence and to provide optimal tracking of the attitude angles while being subjected to unknown dynamics.The global stability proof of the designed controller is provided on the basis of Lyapunov stability theorem.The proposed controller is validated by(i)conducting an experiment through implementing it on the laboratory-based hover system,and(ii)through simulations.Performance of the proposed control scheme is also compared with classical and intelligent controllers.The performance comparison exhibits that the designed controller has quick transient response and improved chattering free steady state performance.The proposed bioinspired global fast terminal sliding mode controller offers improved estimation and better tracking performance than the traditional controllers.In addition,the proposed controller is computationally cost effective and can be implanted on multirotor unmanned air vehicles with limited computational processing capabilities.

Nonsingular Fast Terminal Sliding Mode Control Based on Nonlinear Disturbance Observer for a Quadrotor

Given external disturbances and system uncertainties,a nonsingular fast terminal sliding mode control(NFTSMC)method integrated a nonlinear disturbance observer(NDO)is put forward for quadrotor aircraft.First,a NDO is proposed to estimate the actual values of uncertainties and disturbances.Second,the NFTSM controller based on the reaching law is designed for the attitude subsystem(inner loop),and the control strategy can ensure Euler angles’fast convergence and stability of the attitude subsystem.Moreover,the NFTSMC strategy combined with backstepping is proposed for the position subsystem(outer loop),which can ensure subsystem tracking performance.Finally,comparative simulations show the trajectory tracking performance of the proposed method is superior to that of the traditional sliding mode control(SMC)and the SM integral backstepping control under uncertainties and disturbances.

Study of the EAST Fast Control Power Supply Based on Carrier Phase-Shift PWM

EAST （experimental advanced superconducting tokamak） fast control power supply is a high-capacity single-phase AC/DC/AC inverter power supply, which traces the displacement signal of plasma, and excites coils in a vacuum vessel to produce a magnetic field that realizes plasma stabilization. To meet the requirements of a large current and fast response, the multi- ple structure of the carrier phase-shift three-level inverter is presented, which realizes parallelled multi-inverters, raises the equivalent switching frequency of the inverters and improves the per- formance of output waves. In this work the design scheme is analyzed, and the output harmonic characteristic of parallel inverters is studied. The simulation and experimental results confirm that the scheme and control strategy is valid. The power supply system can supply a large current, and has a perfect performance on harmonic features as well as the ability of a fast response.

A Fractional Order Fast Repetitive Control Paradigm of Vienna Rectifier for Power Quality Improvement

Due to attractive features,including high efficiency,low device stress,and ability to boost voltage,a Vienna rectifier is commonly employed as a battery charger in an electric vehicle(EV).However,the 6k±1 harmonics in the acside current of the Vienna rectifier deteriorate theTHDof the ac current,thus lowering the power factor.Therefore,the current closed-loop for suppressing 6k±1 harmonics is essential tomeet the desired total harmonic distortion(THD).Fast repetitive control(FRC)is generally adopted;however,the deviation of power grid frequency causes delay link in the six frequency fast repetitive control to become non-integer and the tracking performance to deteriorate.This paper presents the detailed parameter design and calculation of fractional order fast repetitive controller(FOFRC)for the non-integer delay link.The finite polynomial approximates the non-integer delay link through the Lagrange interpolation method.By comparing the frequency characteristics of traditional repetitive control,the effectiveness of the FOFRC strategy is verified.Finally,simulation and experiment validate the steadystate performance and harmonics suppression ability of FOFRC.

Fast Control of Negative Pressure Response of a Bio-inspired Suction Cup Actuated by Shape Memory Alloy

A bio-inspired suction cup actuated by shape memory alloy(SMA)for miniature wall climbing robots is developed based on studying characteristics of biological suction apparatus.Some fast control strategies are introduced to improve negative pressure response.Theoretic model of the suction cup is built,and simulation and experiments results indicate the effectiveness of the fast control strategies.The largest negative pressure of the suction cup can reach 14 000 Pa,and its generating and cancelling just need 5 s.Research results indicate the suction cup can be used as an adhesion mechanism for miniature wall climbing robots.

The Non-Singular Fast Terminal Sliding Mode Control of Interior Permanent Magnet Synchronous Motor Based on Deep Flux Weakening Switching Point Tracking

This paper presents a novel non-singular fast terminal sliding mode control(NFTSMC)based on the deep flux weakening switching point tracking method in order to improve the control performance of permanent interior magnet synchronous motor(IPMSM)drive systems.The mathematical model of flux weakening(FW)control is established,and the deep flux weakening switching point is calculated accurately by analyzing the relationship between the torque curve and voltage decline curve.Next,a second-order NFTSMC is designed for the speed loop controller to ensure that the system converges to the equilibrium state in finite time.Then,an extended sliding mode disturbance observer(ESMDO)is designed to estimate the uncertainty of the system.Finally,compared with both the PI control and sliding mode control(SMC)by simulations and experiments with different working conditions,the method proposed has the merits of accelerating convergence,improving steady-state accuracy,and minimizing the current and torque pulsation.

Combined Wind-Storage Frequency Modulation Control Strategy Based on Fuzzy Prediction and Dynamic Control

To ensure frequency stability in power systems with high wind penetration,the doubly-fed induction generator(DFIG)is often used with the frequency fast response control(FFRC)to participate in frequency response.However,a certain output power suppression amount(OPSA)is generated during frequency support,resulting in the frequency modulation(FM)capability of DFIG not being fully utilised,and the system’s unbalanced power will be increased during speed recovery,resulting in a second frequency drop(SFD)in the system.Firstly,the frequency response characteristics of the power system with DFIG containing FFRC are analysed.Then,based on the analysis of the generation mechanism of OPSA and SFD,a combined wind-storage FM control strategy is proposed to improve the system’s frequency response characteristics.This strategy reduces the effect of OPSA and improves the FM capability of DFIG by designing the fuzzy logic of the coefficients of FFRC according to the system frequency index in the frequency support stage.During the speed recovery stage,the energy storage(ES)active power reference value is calculated according to the change of DFIG rotor speed,and the ES output power is dynamically adjusted to reduce the SFD.Finally,taking the IEEE 39-bus test system as an example,real-time digital simulation verification was conducted based on the RTLAB OP5707 simulation platform.The simulation results showthat theproposedmethodcan improve theFMcapabilityofDFIG,reduce the SFDunder thepremise of guaranteeing the rapid rotor speed recovery,and avoid the overshooting phenomenon so that the systemfrequency can be quickly restored to a stable state.

Design and Simulation of an Audio Signal Alerting and Automatic Control System

A large part of our daily lives is spent with audio information. Massive obstacles are frequently presented by the colossal amounts of acoustic information and the incredibly quick processing times. This results in the need for applications and methodologies that are capable of automatically analyzing these contents. These technologies can be applied in automatic contentanalysis and emergency response systems. Breaks in manual communication usually occur in emergencies leading to accidents and equipment damage. The audio signal does a good job by sending a signal underground, which warrants action from an emergency management team at the surface. This paper, therefore, seeks to design and simulate an audio signal alerting and automatic control system using Unity Pro XL to substitute manual communication of emergencies and manual control of equipment. Sound data were trained using the neural network technique of machine learning. The metrics used are Fast Fourier transform magnitude, zero crossing rate, root mean square, and percentage error. Sounds were detected with an error of approximately 17%;thus, the system can detect sounds with an accuracy of 83%. With more data training, the system can detect sounds with minimal or no error. The paper, therefore, has critical policy implications about communication, safety, and health for underground mine.

基于PMAC卡的FAST馈源位姿主动减振控制系统

基于Stewart平台的馈源位姿主动减振定位机构的控制是五百米口径球面射电天文望远镜(FAST)项目实现的关键。考虑到控制系统对重量、体积和精度的要求,提出了在RTLinux环境下,采用工业计算机上下位机主从控制,配合PMAC运动控制卡对机构进行控制的软硬件控制方案。RTLinux对中断处理的强实时性及PMAC运动控制卡强大的运动控制功能,保证了控制精度。实验取得了较好的减振控制效果,满足了FAST的指标要求。同时,PMAC运动控制卡提供了开放性的底层伺服环控制算法,这给今后的控制算法研究改进预留了方便的软硬件接口。

Grey Wolf Optimization Based Tuning of Terminal Sliding Mode Controllers for a Quadrotor

The research on Unmanned Aerial Vehicles(UAV)has intensified considerably thanks to the recent growth in the fields of advanced automatic control,artificial intelligence,and miniaturization.In this paper,a Grey Wolf Optimization(GWO)algorithm is proposed and successfully applied to tune all effective parameters of Fast Terminal Sliding Mode(FTSM)controllers for a quadrotor UAV.A full control scheme is first established to deal with the coupled and underactuated dynamics of the drone.Controllers for altitude,attitude,and position dynamics become separately designed and tuned.To work around the repetitive and time-consuming trial-error-based procedures,all FTSM controllers’parameters for only altitude and attitude dynamics are systematically tuned thanks to the proposed GWO metaheuristic.Such a hard and complex tuning task is formulated as a nonlinear optimization problem under operational constraints.The performance and robustness of the GWO-based control strategy are compared to those based on homologous metaheuristics and standard terminal sliding mode approaches.Numerical simulations are carried out to show the effectiveness and superiority of the proposed GWO-tuned FTSM controllers for the altitude and attitude dynamics’stabilization and tracking.Nonparametric statistical analyses revealed that the GWO algorithm is more competitive with high performance in terms of fastness,non-premature convergence,and research exploration/exploitation capabilities.

Non-Negative Adaptive Mechanism-Based Sliding Mode Control for Parallel Manipulators with Uncertainties

In this paper,a non-negative adaptive mechanism based on an adaptive nonsingular fast terminal sliding mode control strategy is proposed to have finite time and high-speed trajectory tracking for parallel manipulators with the existence of unknown bounded complex uncertainties and external disturbances.The proposed approach is a hybrid scheme of the online non-negative adaptive mechanism,tracking differentiator,and nonsingular fast terminal sliding mode control(NFTSMC).Based on the online non-negative adaptive mechanism,the proposed control can remove the assumption that the uncertainties and disturbances must be bounded for the NFTSMC controllers.The proposed controller has several advantages such as simple structure,easy implementation,rapid response,chattering-free,high precision,robustness,singularity avoidance,and finite-time convergence.Since all control parameters are online updated via tracking differentiator and non-negative adaptive law,the tracking control performance at high-speed motions can be better in real-time requirement and disturbance rejection ability.Finally,simulation results validate the effectiveness of the proposed method.

EPICS应用于FAST主反射面控制系统的研究

500 m口径射电望远镜FAST主动反射面的控制是望远镜工程建设的重要部分。在介绍了实验物理与工业控制系统(EPICS)架构的相关技术后,提出将EPICS架构应用到FAST主动反射面控制系统中的设计思想和控制方案。并针对FAST密云30 m模型主动反射面控制,进行了基于EPICS架构的系统开发。详细介绍了软硬件的设计结构和内容,为FAST原型主反射面控制以及其它子系统的控制提供了基于EPICS架构的参考依据。

A novel MPTC sensorless control strategy for ANFTSMC with ESO to control PMSM

Aiming at the problem that the traditional control strategy of permanent magnet synchronous motor(PMSM)for electric vehicles has low control performance,a novel adaptive non-singular fast terminal sliding mode control(ANFTSMC)model predictive torque control(MPTC)strategy is proposed.A new adaptive exponential approach rate is designed,and the traditional switching function sgn()is replaced by the hyperbolic tangent function tanh().A new ANFTSMC with extended state observer(ESO)is constructed as the speed regulator of the system,and ESO can observe disturbances.This improved method weakens chattering and improves the robustness of the system.To realize sensorless control of the speed control system,an ESO speed observer based on tanh(Fal)is constructed.Compared with the traditional ESO based on Fal function,the observation error is smaller,and the observation accuracy is higher.Finally,aiming at the model predictive torque control strategy used,a new objective function construction method is proposed,which avoids the design of weight coefficient,and the traditional voltage vector selection method is improved and optimized,which reduces the calculation amount of the algorithm.

Adaptive Noise Cancellation Method Used for Wheel Speed Signal of Integrate ABS/ASR System

A novel adaptive noise cancellation method for wheel speed signal of the anti-lock braking system/ anti-slip regulation（ABS/ASR） control system is proposed. Based on the spectrum distribution of vehicle＇s wheel speed signal got from fast Fourier transform under various conditions, the high-pass filter is used to deal with original wheel speed signals sampled to get reference noise signal and the original wheel speed signals are used as adaptive filter＇s desired outputs. The difference between original signals and reference noise signals is used as the error signal for the adaptive FIR filter and also used as the whole adaptive noise cancellation system＇s final output. This method can obtain the noise signal on-line and is easy to use for. real control system, which is useful to improve the performance of integrate system ABS/ASR.

FAST主动反射面控制系统中节点控制器记录的设计

主动反射面是FAST(Five-hundred-meter Aperture Spherical radio Telescope)望远镜的一个重大创新之一,其性能将直接关系到整个望远镜的性能,因此主动反射面的控制需要一个实时高效的控制系统。基于EPICS(Experimental Physics and Industrial Control System)的输入输出控制器(Input/Output Controller,IOC)框架,充分利用EPICS的实时性,根据FAST反射面的控制节点达2 000多个的特点设计了新的记录类型——节点控制器记录,以便于控制器节点IOC的管理以及提高代码的复用,并针对FAST主动反射面密云模型对实际装置进行了仿真、设计和部分测试。

6000t自由锻造水压机改油压机关键技术研究

本文提出了6000t自由锻造水压机升级改造的必要性,介绍了6000t自由锻造水压机升级改造的路径及改造后主要参数,阐述了控制系统升级改造方案及其关键技术。