Optimal State Feedback Control for Pulsed Power Supplies

According to the characteristics of rapid response and low sensitivity of the Hall element, combined with the data processing methods of sample/hold and AD conversion widely used in engineering applications at present, it is explored to drive the Hall element by pulsed power supply, and increase the magnetic sensitivity of Hall element by sampling at the peak voltage. The conditions about the temperature rise of the Hall element driven by pulsed power supply are theoretically analyzed. The equivalent relationship of temperature rise between pulsed and DC power supply is put forward. It is pointed out that the peak power and peak voltage can be converted into equivalent power and equivalent voltage to reflect the temperature rise of the Hall element. The experimental results verify the equivalent relationship of the temperature rise.

Background: High-temperature alloys, such as the nickel-based alloy, have become the main materials for core components in the aerospace field because of their high strength and good toughness. Therefore, how to improve the machining accuracy and stability of electrochemical machining (ECM) of small deep holes on nickel-based alloy is an important topic for studies. The instantaneous high-density current during the pulse width of pulse ECM is beneficial to the dissolution of nickel-based alloy. Many experts and scholars have studied pulse ECM of small deep holes. Objective: The purpose of this article is to propose and design a positive and negative pulse (PANP) power supply to study the accuracy and stability of ECM of small deep holes on the nickel-based alloy. Methods: First of all, an H-bridge composed of four MOSFET switches is designed to achieve PANP output in the main circuit of the power supply. Then, this article discusses the influence of the ratio of positive and negative pulses on short circuits, the influence of the ratio of positive and negative pulses on the mass removal rate, and the influence of the electrolyte concentration and pulse width on the mass removal rate. Finally, according to the obtained optimal parameters, the influence of the electrolyte pressure on the average radial overcut of hole depth is analyzed. Results: The experimental results show that the short-circuit frequency is reduced by more than 50% compared with non-negative pulses power supply; the ratio of positive and negative pulses, pulse width, and electrolyte concentration and pressure were optimized by experiments in order to improve the mass removal rate of the workpiece and the average radial overcut of hole depth. Conclusion: The designed PANP power supply can improve the machining accuracy and stability of ECM of small deep holes on the nickel-based alloy.

Due to the influence of electromagnetic force, sliding riction, air resistance and other factors, the dummy load of the pulsed power supply (PS) changes with the launch process in the electromagnetic railgun launch system, the characteristics of pulsed PS can not be accurately studied using the fixed resistance and inductance to simulate the load of pulsed PS. Therefore, the mathematical model of the pulsed PS based on the multiple high-temperature superconducting pulsed power transformer (HTSPPT) was built, in this model, a dynamic model including various forces simulates the load. The simulation results show that if the influence of various forces is ignored, the characteristic parameters of pulse PS will have large errors.

A stochastic minimax optimal time-delay state feedback control strategy for uncertain quasi-integrable Hamiltonian systems is proposed. First, a stochastic optimal state feedback control problem of uncertain quasi-integrable Hamiltonian system with time delay in feedback control subjected to Gaussian white noise is formulated. Then, the time-delayed state feedback control forces are approximated by the control forces without time delay and the original problem is converted into a stochastic optimal state feedback control problem of an uncertain system without time delay. After that, by following a procedure based on the stochastic averaging method and stochastic differential game, the worst-case disturbances and the optimal controls are obtained from solving a Hamiltonian–Jacobi–Isaacs (HJI) equation. As an example, the stochastic minimax optimal state feedback control of a Duffing oscillator with parametric disturbances and time-delayed feedback control is worked out in detail to illustrate the procedure and effectiveness of the proposed control strategy.

This paper studies the problem of optimal parallel tracking control for continuous-time general nonlinear systems. Unlike existing optimal state feedback control, the control input of the optimal parallel control is introduced into the feedback system. However, due to the introduction of control input into the feedback system, the optimal state feedback control methods can not be applied directly. To address this problem, an augmented system and an augmented performance index function are proposed firstly. Thus, the general nonlinear system is transformed into an affine nonlinear system. The difference between the optimal parallel control and the optimal state feedback control is analyzed theoretically. It is proven that the optimal parallel control with the augmented performance index function can be seen as the suboptimal state feedback control with the traditional performance index function. Moreover, an adaptive dynamic programming ( ADP ) technique is utilized to implement the optimal parallel tracking control using a critic neural network ( NN ) to approximate the value function online. The stability analysis of the closed-loop system is performed using the Lyapunov theory, and the tracking error and NN weights errors are uniformly ultimately bounded ( UUB ) . Also, the optimal parallel controller guarantees the continuity of the control input under the circumstance that there are finite jump discontinuities in the reference signals. Finally, the effectiveness of the developed optimal parallel control method is verified in two cases.

We consider a finite-horizon continuous-time optimal control problem with nonlinear dynamics, an integral cost, control constraints and a time-varying parameter which represents perturbations or uncertainty. After time-discretization of the problem we employ a Model Predictive Control (MPC) algorithm with a shrinking horizon, which uses a "prediction"/forecast for the uncertain parameter and (possibly inexact) measurements of the state vector, and generates a piecewise constant control signal by solving auxiliary open-loop control problems. In our main result we derive an estimate of the difference between the MPC-generated control and the optimal feedback control, both obtained for the same value of the perturbation parameter, in terms of the step-size of the discretization and the measurement error. We also give an estimate for a norm of the difference between the MPC-generated control and the optimal open-loop control in the problem with the "true" value of the uncertain parameter, depending on the prediction error.

Design and characteristics of a modular integrated power supply for the system of flashlamp-pumped in inertial confinement fusion

Novel coronavirus pneumonia affects the health of people all over the world. In this study, UV pulse high-light sterilization technology was used to combat coronavirus. The light source of the ultraviolet pulsed high-light disinfection robot is a kind of high-brightness flash light source using pulsed xenon lamps as the output load. This paper developed a pulsed xenon lamp power supply with a high-voltage pulse synchronous trigger function, a DC charging voltage of 1kV-3kV, an output pulse current range of 1kA-3kA, and a pulse width of 50μS for a pulsed xenon lamp with a 196mm×Φ10mm and a resistivity of 12Ω⋅A1/2. This paper presented the experimental results of charging voltage of 1kV, output pulse current peak value of 1kA, and pulse width of 50μS. The power supply design was based on the phase-shifting voltage regulation mode of UC3825 control power MOS tube, through the sampling isolation module and the closed-loop feedback formed by STM32 control, the energy storage capacitor was linearly charged through the DC voltage sampling and voltage regulation control module; the trigger pulse signal was generated by the SCR switch, and the xenon lamp was turned on and emits flash light after the pulse transformer was boosted. The sample test results verified the feasibility of the power supply design principles and technical solutions.

Traps equipped with low-power LEDs are very promising for use in insect pest control due to their safety for the non-target entomofauna. However, the level of natural illumination at night at high latitudes varies greatly and the attractiveness of low-power LEDs in early summer (i. e. during the period of white nights) becomes too weak to ensure acceptable catch of harmful insects in traps. The purpose of this article is to illustrate a successful attempt, using the example of the diamondback moth, Plutella xylostella (L.), to enhance the attractive effect of low-power LEDs by replacing their direct current supply with a high-frequency pulsed (30 kHz) power supply. Diamondback moth adults were collected in the vicinity of St. Petersburg in 2020–2024 using Delta plastic traps equipped with LEDs and a synthetic sex attractant as a control. The results obtained proved that upgrade of LEDs power supply provides significant increase in diamondback moth adult catch by light traps, exactly 4.57 times during the period of white nights, 3.11 times during the dark nights following them, and 4.45 times during the summer as a whole. The results achieved are important not only from a practical point of view, but also have theoretical value, since the effect of flickering light on insect behaviour has been very insufficiently studied.

With the development of the global first fourth electron cyclotron resonance (FECR), plasma of highly charged ions produced under high microwave frequencies required to be constrained strictly by symmetric high magnetic field. Using pulsed power supply to generate the magnetic field has cost-effective advantage over superconducting power supply. In this paper, a pulsed power supply is utilized to generate symmetric high magnetic field. The pulsed power supply must provide large inductive loads with a fast pulse current ramping from 0A to 2700A between 50 ms and 70ms. The stability of current is 6×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-5</sup> and the repeatability of current is about 2×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> at the flat top current waveform. For this purpose, a digital controller based on Xilinx 7000 FPGA is designed and implements a control strategy of double current loop in series. The experiment results show that the index of pulsed power supply is successfully fulfilled.

Development of the 320 kA pulsed magnetic horn power supply with a novel energy recovery system for the T2K experiment

3D asymmetric magnetic reconnection is an important investigation of the Space Plasma Environment Research Facility, which is being built as a user facility at the Harbin Institute of Technology in China. Four magnetosheath coils, which consist of Poloidal Field (labeled PF) coils and Toroidal Field (labeled TF) coils, are used to generate the magnetic field and plasma environment for the reconnecting experiment. A capacitor-based pulsed power supply (PPS) system with a modular design is developed to excite the magnetosheath coils to generate the required amplitude and duration of the magnetic field. The PPS system includes the PF PPS and TF PPS, which include four sets of PPSs, respectively. Each set of PF PPS and TF PPS consists of nine modules and four modules, respectively, and each module consists of a charge and discharge unit. The PF PPS can provide a pulsed current of no less than 360 kA for the corresponding PF coil at 0.11ms when the charging voltage is 20 kV, and the duration of the pulsed current from the peak to 10% of the peak is no more than 0.6ms. The TF PPS can provide a pulsed current of no less than 200 kA for the corresponding TF coil at 0.08ms when the charging voltage is 20 kV, and the duration of the pulsed current from the peak to 10% of the peak is no more than 1.6ms. The detailed design of the PPS has been discussed in this paper, and the detailed design of the main components in the discharge unit of the PPS is also given in this paper. Finally, the discharge tests of all the PPSs are carried out to verify the design of the PPSs, and the results of the PPSs in discharge tests indicate that all the PPSs meet the design requirements.

Study of the charging circuit of a pulsed solid-state laser power supply: A new concept of high charging efficiency and realization

Atmospheric pressure gliding arc discharge has a wide range of applications in the fields of energy environment and material processing. During the discharge process, with the conversion of the gliding arc discharge mode, for the driving power supply, the output of the discharge process is from an open circuit to a near short circuit. There are two kinds of work. The switching of states requires an additional design of overcurrent-short-circuit protection methods suitable for gliding arc discharge applications. The nanosecond pulse power supply is the most potential excitation power source in the field of gliding arc discharge, and has broad application research prospects. In order to solve the problem of overcurrent and short circuit at the output terminal caused by gliding arc discharge, this paper proposes an over-current-short-circuit protection solution based on a Marx generator-based nanosecond pulse power current-limiting protection module and an automatic quick-cutting protection module. By analyzing the working process of the Marx pulse power supply and the working characteristics of the MOSFET, a current-limiting scheme to transfer the switch from the saturation region to the variable resistance region is designed, and the calculation method of the parameter design of the current-limiting resistor network is designed. At the same time, in order to solve the problem that the current-limiting protection scheme cannot cope with the normal short-circuit of the output terminal, an automatic quick-cut protection module is designed, including a short-circuit detection circuit, a fault latch circuit and an action circuit, which realizes the high-reliability triggering of the short-circuit fault signal, thereby solving the problem of a normal short-circuit at the output terminal. Finally, through the simulation experiment method, the feasibility of the over-current short-circuit protection scheme proposed in this paper is verified.

The deposition of hard crystalline Al 2O 3 layers by means of bipolar pulsed magnetron sputtering