Power Supply Control Research Articles

Strategies for Inverter Dual-output Shore-to-ship Seamless Power Supply

This paper simulates the micro-grid to establish a shore-to-ship seamless connection power supply system and control strategy by the shore-controlled inerter dual-output. The shore-controlled 60Hz inverter power supply and the 50Hz inverter transition transformer are directly supplied without changing the control of the ship power station. The shore-ship power supply is seamlessly connected through the shore-controlled inverter, which is suitable for most ships. The strategies for inverter dual-output shore-to-ship seamless power supply are: V/f control method controls inverter constant frequency constant voltage power supply; P/Q control method controls shore ship seamless connection and smooth transfer load; Phase-locked loop control method controls phase-shifting and variable-frequency control of the shore power during the integration of shore power into the ship's power to complete the parallel condition, assisting to stabilize the frequency and voltage of the output of the rectifier inverter; Inverter control reduces frequency and voltage fluctuations of V/f control and P/Q control conversion by following from state following to reverse state following innovation.

Power Supply Control Strategy for Offshore Wind Ship

The electric load of the ship at the bottom berth of the floating offshore wind farm platform is compatible with the power generation of the wind farm generator. The 60Hz ship power and 50Hz wind power adopt frequency conversion, the 50Hz ship power and the 50Hz wind power use the inverter to smoothly switch seamlessly, and the seamless power supply ensures that the ship can be easily and quickly berthed in a short period of time. Based on the inverter power supply control strategy of virtual synchronous generator (VSG) control and grid-connected working mode and autonomous mode of the system small-signal model, the VSG has the characteristics of fast tracking and certain mechanical and electrical inertia compared with the frequency variation of the inverter power supply based on the droop control. Meanwhile, the grid-connected pre-synchronization process and the synchronous generator pull-in synchronization process have similar characteristics, and the frequency and voltage change amplitude are relatively flat. The simulation analysis and experimental results verify the correctness of the control strategy.

Smart Micro-grid System with Wind/PV/Battery

A 6kW smart micro-grid system with wind /PV/battery has been designed, the control strategy of combining master-slave control and hierarchical control has been adopted. An energy management system based on battery SOC has been proposed for the smart micro-grid system so that the management functions, such as measurement and testing, protection, operation mode selection, power supply control and load management of the smart micro-gird, can be realized. The performance of the micro grid and the control strategy presented in the paper has been demonstrated and verified in various operation modes, including direct supply of wind and solar energy, energy feedback to grid, power supply from battery, power supply by external power grid and load limitation modes.

Design of high-accuracy eight-channel surface electromyography acquisition system and its application

The surface electromyography (sEMG) acquisition system has the advantages of small size, high precision, low power consumption and easy operation. We have developed a low-cost and portable eight-channel sEMG acquisition system, in which consists of the related analog front end (AFE), main control unit (MCU) and power supply system. The AFE circuit converts the sEMG signal to the digital signal after filtering the direct current and the two stage amplification. The MCU controls the analog-to-digital converter (ADC) using serial peripheral interface (SPI), packages the data and sends the data to the android through a high-speed wireless module. The power supply system provides stable voltage source and can be powered by battery. Experimental results show that the designed eight-channel sEMG acquisition system exhibits an excellent electrical performance with the amplifier resolution of 8.1 μV, the system noise of lower than 15.3 μV, the sampling rate of 1000 Hz and power consumption of about 30.7 mW. The recognition rate is as high as 98% using support vector machines when detecting normal and fatigue state. This device can be applied in the fields of family health monitoring and the detection of the muscle state in daily life and work.

Adaptive DC-Link Voltage Control of LLC Resonant Converter

In this study, an adaptive DC-link voltage control of a two-stage switching power supply with LLC resonant converter is proposed. With this control method, the frequency variation range can be reduced and the conversion efficiency under different load conditions can be improved compared with the conventional variable frequency control technique. By operating the LLC resonant converter near its resonant frequency, circulating loss as well as the conduction loss can be reduced and optimal design of LLC resonant converter can be made possible. Moreover, no additional auxiliary circuits are required for the proposed method. The operational principle of the proposed control scheme is verified with a 350 W prototyping circuit. The switching-frequency-variation range is reduced from 12 to 4 kHz and the efficiency is improved from 89.4 % to 90.2 % at full load.

Features of the new VON ARDENNE BeamGuidance system

With the Variocathode EB Gun series completed in 2004 and the fully digital control of High Voltage Power Supplies introduced in 2014, the focus of EB product development has now been directed to the BeamGuidance System. This year, the new VON ARDENNE BeamGuidance will be implemented for the first large EB melting furnace and EB production coater.Based on standard industrial hardware components, a completely new signal processor and HMI software was developed. Sophisticated procedures implemented on the signal processor calculate all dynamic beam scanning sequences for multiple EB guns in real time including automatic figure movements, coordinate transformations and dynamic corrections. Although the beam scanning sequences are defined with discrete coordinates, the new BeamGuidance allows for both quasi-digital (point to point) and analog (continuous) electron beam movement. With further new key features like synchronization of multiple beams, synchronization to external events and extended time and power distribution based figure manipulations, the new BeamGuidance System provides a new quality for control of EB processes.

Novel welding machine based on small PMSG wind turbine

This paper investigates a small wind turbine based on a permanent magnet synchronous generator (PMSG) to replace the used diesel generator in welding machines at remote sites. The proposed welding machine is designed using a variable-speed PMSG wind turbine to achieve an optimal performance. The problem of fluctuation in wind energy is solved by adding a storage battery and a maximum power point tracking (MPPT) stage. A controllable direct current power supply based on the full-bridge inverter topology is adopted for the welding side. The control strategies of MPPT, pitch angle blade, and arc welding current are also discussed. Matlab/Simulink is utilized to simulate the proposed system. Simulation results show that the proposed welding machine can provide a stable and robust welding current under varying wind and arc load conditions. Simulation results demonstrate the feasibility and efficiency of the proposed welding machine.

Constant temperature control of tundish induction heating power supply for metallurgical manufacturing

The tundish induction heating power supply (TIHPS) is one of the most important equipment in the continuous casting process for metallurgical manufacturing. Specially, the constant temperature control is greatly significant for metallurgical manufacturing. In terms of the relationship between TIH load temperature and output power of TIHPS, the constant temperature control can be realized by power control. In this paper, a TIHPS structure with three-phase PWM rectifiers and full-bridge cascaded inverter is proposed. Besides, an input harmonic current blocking strategy and a load voltage feedforward control are also proposed to realize constant temperature control. To meet the requirement of the system, controller parameters are designed properly. Experiments are conducted to validate the feasibility and effectiveness of the proposed TIHPS topology and the control methods.

Mathematical Differential Models and Methods for Assessing the Cybersecurity of Intelligent Computer Networks for Control of Technological Processes of Railway Power Supply

The problem of cybersecurity of computer networks for control of power supply at the level of railroads is analyzed and a graph of the topology of a computer network for control of power consumption is proposed. Based on the Pukhov theory of differential transformations, a number of differential mathematical models are proposed to assess the level of cybersecurity of a computer network for control of power supply. For differential images, a cybersecurity criterion is proposed and the minimax principle is developed for the worst combination of the intensity of cyberattacks and the flow of protective actions. A method of predictive search for an optimal cybersecurity strategy by the extremum analysis of a functional for the case of stochastic intensity of flows of cyberattacks is developed.

Time Synchronization Network for EAST Poloidal Field Power Supply Control System Based on IEEE 1588

This paper clearly demonstrates the architecture of time synchronization network of experimental advanced superconducting tokamak (EAST) poloidal field (PF) power supply control system and analyzes characteristics of the IEEE 1588 in detail at the same time. IEEE 1588 has unique advantages for this paper to utilize as protocol in order to improve the accuracy of the time synchronization network (TSN). Consequently, we design a time synchronization system based on PCI eXtensions for Instrumentation-6683H. This paper utilizes one master node to synchronize all slave nodes on the time network in each second. The result shows that the synchronization accuracy can be achieved within 50 ns. According to results of experiments, this system can perfectly meet the requirements of EAST PF power supply control system.

Analysis and control of tundish induction heating power supply using modular multilevel converter

Modular multilevel converters (MMCs) provide advantages to reach medium-voltage operation increasing the power level in industrial applications. In this study, a tundish induction heating power supply based MMC (MMC-TIHPS) is investigated for heating molten steel. The equivalent model of MMC-TIHPS is established and the energy in horizontal and vertical directions are analysed. The heating control for molten steel consists of temperature increasing and constant temperature processes (alternatively called transient-state and steady-state operation). The main contribution of this study is to propose a direct power feedforward control based load current feedforward strategy for TIHPS. With this strategy, TIHPS can be controlled operating with full power to heat molten steel in transient state and guarantee the insulation effectiveness in steady state. Proper parameters of controllers are designed. Experimental results are conducted to validate the feasibility of MMC-TIHPS and the effectiveness of the proposed control method.

Quasi-Interleaved Current Control for Switch-Linear Hybrid Envelope-Tracking Power Supply

An envelope-tracking (ET) technique can greatly enhance the efficiency of the power amplifier in wireless communication system. Among the structures of the ET power supply, the switch-linear hybrid (SLH) structure can obtain both high-tracking bandwidth and high efficiency. An implementation of series–parallel-form SLH ET power supply is proposed in this paper, which includes one multilevel converter, one linear amplifier, and two buck converters. The two buck converters adopt current sensor-less prediction control and are operated at critical conduction mode (CRM). In order to ensure the operation of CRM and provide as much load current as possible, a quasi-interleaved current control scheme is proposed for the two buck converters. Moreover, a peak current restriction method is proposed to prevent the output current of the two interleaved buck converters from excessively exceeding the load current, avoiding the increase of the power loss in the linear amplifier. Finally, a prototype is fabricated with the specifications as 5-MHz tracking bandwidth, 9.6–26.4-V output voltage, and 20-W average output power. The overall measured efficiency is 81.0%, and the normalized-mean-square error is 0.28% when tracking the envelope of wideband code division multiple access signal.

AC-AC Voltage Controller of Power Supply for Heater on Drying System

The coconut fruits is very useful to be processed into cooking oil and it can meet the needs of cooking for Indonesia people, But before the coconuts processed into oil, The coconuts should be dried first. Usually the drying process is manually, that is dried in the sun. Unfortunately this way is not hygienic and can’t be done continuously, causing the coconut fungus overgrow. This paper proposes methode to solve the problem above.This research makes the dryer coconut fruitssystem by using the heater.Dryer system used for dry some coconut fruits that must be reduced the water content up to 5%, this dry coconutis called copra. System requires heater which will be regulated the temperature. Heater temperature setting is done by adjusting the heater supply voltage, and this is the task of ac to ac voltage controller. Ac to ac voltage controller is a circuit converter is capable converting ac voltage with value 220 Vrms at 50 Hz frequency and have waveform pure sinusoidal become ac voltage frequency at 50 Hz with an output voltage suitable with our need but the voltage waveform not impure sinusoidal or defective as a result firing angle effects. The output voltage which we set determines the value of the heater temperature. The output voltage is set from the firing angle of the triac component using the addition and decreasing angle values. Based on the results of experiments that have been done, if the drying chamber which has volume 135.2 liters and the temperature regulated at 700 C then the heater with a power requirement of 400 W should receive supply 216 V from ac to ac voltage controller. So the triac of ac to ac voltage controller fired on 0.55 radians so that the to ac voltage controller that gets 220 V input voltage can produce 216 V output voltage.

Smoothly Varying Injected Neutral Beam Voltage and Current Provides New Capability on the DIII-D Tokamak

A significant engineering upgrade of the DIII-D neutral beam system has recently completed, providing ability to smoothly and independently vary the beam voltage and current. This enables greater control of the injected beam power, torque, and plasma instability drive for fusion experiments. Modifications to the high-voltage equipment and the plasma control system were made and tested over the last year to allow beam energy to vary by as much as 20 kV over a 0.5-s period anywhere within the 45–85 kV operating range of the beams. The beam current can be made to track the voltage (keeping the perveance constant), or the current and voltage can be varied independently (scanning the perveance). The smooth variation of beam energy avoids the extremely perturbative effects of pulsewidth modulation, the only tool previously used for regulating the injected neutral beam power. With independent control of voltage and current, the beam ion velocity space can be tailored to facilitate new experiments that explore, for example, the detrimental effects of Alfven eigenmodes. These modes are driven by energetic particles and can possibly be avoided in steady-state scenarios by timely variation of the beam energy while maintaining constant input power. A description of the modifications made to the power supply and beam controls will be presented, as well as some initial physics results employing the new variable beam energy system.

Inertial piezoelectric linear motor driven by a single-phase harmonic wave with automatic clamping mechanism.

A novel, single-phase, harmonic-driven, inertial piezoelectric linear motor using an automatic clamping mechanism was designed, fabricated, and tested to reduce the sliding friction and simplify the drive mechanism and power supply control of the inertial motor. A piezoelectric bimorph and a flexible hinge were connected in series to form the automatic clamping mechanism. The automatic clamping mechanism was used as the driving and clamping elements. A dynamic simulation by Simulink was performed to prove the feasibility of the motor. The finite element method software COMSOL was used to design the structure of the motor. An experimental setup was built to validate the working principle and evaluate the performance of the motor. The prototype motor outputted a no-load velocity of 3.178 mm/s at a voltage of 220 Vp-p and a maximum traction force of 4.25 N under a preload force of 8 N. The minimum resolution of 1.14 μm was achieved at a driving frequency of 74 Hz, a driving voltage of 50 Vp-p, and a preload force of 0 N.

Exploration of the Voltage Control Mode of Second-Generation EAST Fast Control Power Supply

To achieve the maximum current rising rate, the second-generation fast control power supply (FCPS) applies voltage control mode while retaining the first-generation current tracking mode. When the power supply outputs high voltage, the accompanied frequent overcurrent protection will return the power to dc side, which leads to overvoltage protection, so the current limiting protection is applied. Experimental results prove that voltage mode can greatly improve the ability to suppress vertical unstable displacement of plasma.

AC insulation monitoring technology for EAST fast control power supply

To ensure the stable operation of Experimental Advanced Superconducting Tokamak (EAST) fast control power supply, a new alternating current insulation monitoring technique is presented in this Letter which is suitable for the high-frequency and high-voltage working environment of EAST fast control power supply. The method uses alternately switching resistance in an unbalanced bridge to change the voltage, and detects the voltage in real time, then calculates the insulation resistance. The simulation platform based on Simulink was built to carry out real-time insulation monitoring analysis of EAST fast control power supply as voltage input, the waveforms of which were consistent with the expected. Through experimental verification, the new method can work well for EAST fast control power supply.

Orbit and Positioning Accuracy for New Generation Beidou Satellites during the Earth Eclipsing Period

The Beidou System (BDS) started functioning at the end of 2012. The Yaw-Steering (YS) attitude mode for Inclined Geosynchronous Orbit (IGSO) and Medium Earth Orbit (MEO) satellites in BDS ensures that the solar panels face the Sun. The orbit radial accuracies for IGSO/MEO satellites are 0·5 m and the User Equivalent Range Errors (UERE) are 1·5 m in YS mode. BDS-2 satellites adopt Orbit-Normal (ON) mode to meet the power supply and thermal control requirements of the satellite during deep Earth eclipse periods. In ON mode, long-term orbit ephemeris accuracy monitoring in the Operational Control System (OCS) of BDS indicates that the orbit accuracies for IGSO/MEOs are reduced to a few hundreds of metres, seriously affecting the positioning accuracy and navigation service capability of the BDS system. Solar Radiation Pressure (SRP) is difficult to model in ON mode. Continuous Yaw-Steering (CYS) mode is available for new generation Beidou satellites launched since 2015. The orbit accuracies for these new generation Beidou (BDS-3) satellites were estimated based on BDS monitoring station data and SRP models including ECOM 9/5/3. The evaluation method consisted of four steps, namely, orbit internal consistency analysis, UERE calculation, Satellite Laser Ranging (SLR) data fitting Root Mean Square (RMS) determinations and positioning performance analysis; the data gathering period lasted for more than 60 days and included two CYS periods and one ON period. The experiments showed that the orbit accuracy of the radial component in CYS mode for the BDS-3 satellites degrades by 2 to 3 cm and positioning accuracy degrades only by 1 cm over that in YS mode which is just a small reduction in accuracy compared with the decimetre-level BDS orbit accuracy and the metre-level single point positioning accuracy with BDS pseudorange data. This overcomes declining orbit and positioning accuracy issues in ON mode for BDS-2 satellites. Other results also show that the reliability of BDS has been improved.

Agent‐based identification and control of voltage emergency situations

Changing dynamics of power systems caused by the migration from conventional to distributed energy sources increase the risk of blackouts due to voltage instability, especially in case of unforeseen network conditions (e.g. (N-k)-cases). To enable both secure and efficient power supply, novel monitoring and emergency control systems for the identification of voltage emergency situations as well as the execution of control actions are required that react reliably in due time and adaptively in the case of changing network situations. This study presents a distributed agent-based approach to counteract voltage instability that is based solely on local measurements and limited inter-agent communication. Distributed agents located at substations in the (sub-)transmission network monitor distribution and transmission voltages, as well as, load tap changer positions and are able to autonomously curtail load in case system stability is endangered. The applicability of the approach is demonstrated in a co-simulation environment interfacing the multi-agent system with a dynamic power system simulation. The presented approach allows for an early detection of voltage instability as well as a coordinated execution of available control actions.

APPLICATION OF MICROPROCESSOR SYSTEMS IN AUTOMOTIVE INDUSTRY

Questions of application of microprocessor systems for their automation are considered an automation condition on existing designs of truck. It is noticed that now the majority of truck exhausted in the CIS are automated only partially. By automation are captured: control, preliminary treatment of a condition of systems and the information on them; control of start, partially control by power-plant work; control of sprinkling fuel; control of power supply; control of brakes, antiblocking systems, airbags; climate control maintenance; illumination.Scopes of microprocessor systems in cars and microcontrollers used for this purpose taking into account that now it is required to expand areas of automation of systems of cars considerably are considered. The analysis of systems and the functions which are subject to automation for truck and special cars is carried, questions of application of microprocessor systems for reception of experimental data on roads (microprofile and longitudinal cross-section) and their use at car modelling, and also maintenance of road safety: distance maintenance between cars, control of blind zones; an exception засыпанияthe driver during movement, reduction of harmful influence from noise and vibrations.It is offered complexing realised functions and systems of their control. The short description and a substantiation of expediency of application of means of automation on the basis of the cheap microprocessor modules Arduino is given, allowing considerably to reduce quantity of used microcontrollers. Block diagrammes of realisation of problems of traction dynamics in package MatLab/Simulink, transformations and horizonting of truck and special cars by means of MC Arduino are resulted. Recommendations to introduction of systems of automation for truck and special cars are made.