Traditional Power Supply Research Articles

Driven by Density, Efficiency at Low Cost, Power Integration Reaches New Heights: PSiPs and PwrSoCs are growing faster than the traditional power supplies

For decades, miniaturization has been the trend in the power supply world. Consumers have been demanding more functions from smaller systems with better performance and reliability at lower cost. Such advances are evident in today’s laptops, tablets, smartphones, industrial drives and a host of other consumer and industrial applications. To meet these demands, the power supply industry has also kept pace with the needs of the markets. As a result, power integration, both in package and on-chip, has continued to evolve for more than a decade. Consequently, with this evolution, power density has risen from tens of watts to hundreds of watts from compact semiconductor packages with high performance in efficiency, density, reliability and other such metrics. On-chip, we are talking about tens of watts delivered from monolithic semiconductor substrates.

A stand-alone hydrogen photovoltaic fuel cell hybrid system for efficient renewable energy generation

Today the main concern for World is energy and power age. By and by, out of around 7 billion populaces, just 65-69% approaches power. Essentially to carry the populaces into the office of power access however much as could be expected inside the restricted assets, we have used the regular assets like sun oriented and wind to satisfy this assumption. Utilizing sun based and wind energy in relationship with the power gadgets, we can supply the power to the buyers inside their capacity and we will want to limit the power issue as could really be expected. Hydrogen Photovoltaic Fuel (HPF) cell is the mix of force gadgets which lessens the major sun oriented emergency of expenses, where expenses are the enormous issue for non-industrial nations. Presently a-days, the coordinated circuits (IC) are entirely solid and modest, to the point that make the conveying and reversing or changing over components simplest than the massive and expensive instruments utilized in the traditional power supply framework. The examination expects that the lattice joining of the environmentally friendly power assets utilizing HPF inverter might cause a colossal comment in satisfying the absence of force use across the world. Solar energy is a rapidly growing resource, already providing 4.5% of electricity in the World and projected to supply up to 35% by 2050. On the other hand, the default model’s predictions were far from the actual metered HPF data. For renewability, the simulated renewable energy consumption with modified inputs is 3.9% below of actual metered renewable data while the default model’s prediction was more than 52% below actual renewable use. Using PV-HPF hybrid model indices to represent how well a simulated model describes the variability in the measured data; the modified model has achieved accurate renewability results; with a Solar of 10.99 % and Wind of 9.90%, while the hybrid model has a solar of 57.16% and a Wind of 57.20% in renewable energy comparison being performed in MATLAB.

Study on characteristics of EDM using pulse power supply with active high-frequency oscillation

One main disadvantage of electrical discharge machining (EDM) is its low machining efficiency, which limits the further application of EDM. Comparing the spark discharge waveform and the arc discharge waveform under the transistor pulse power supply, it can be found that a high-frequency oscillation component is presented in the spark discharge waveform during the discharge, while the high-frequency oscillation component does not exist in the arc discharge waveform. Inspired by this phenomenon, a new pulse power supply with active high-frequency oscillation was developed in this study, which can provide rectangle pulse discharge current with high-frequency oscillation component. Experimental results show that compared with the traditional transistor type pulse power supply that only generates rectangle discharge current, the pulse power supply with active high-frequency oscillation component can improve the machining efficiency effectively and reduce the tool electrode wear without influencing the surface roughness. Further, the influences of the oscillation frequency and the oscillation amplitude of on the machining characteristics were investigated. In addition, under active high- frequency oscillation current, by the high-speed observation of the arc plasma, the measurement of the discharge craters and the statistics analysis of the effective discharge rate, the influence mechanism of active high-frequency oscillation current on the material removal of EDM was discussed.

SOLAR THERMAL ELECTRIC GENERATOR FOR AGRICULTURE

Solar cells convert solar electromagnetic energy into electrical energy. When fully illuminated, one element generates electricity with a voltage of 0.5 volts. For practical use in generating electricity, solar cells are combined into a photo panel. (Research purpose) The research purpose is in developing a functional and technological scheme of a solar thermal electric generator for power supply to remote agricultural facilities using renewable solar energy. (Materials and methods) During the research there were used method of patent search on the websites of the Eurasian Patent Organization, the World Intellectual Property Organization (WIPO), Rospatent and Google Patents. The article presents the thermoelectric generator assembly based on Peltier thermoelectric modules and a solar concentrator for generating electricity. (Results and discussion) The article presents the functional and technological scheme of a heliothermoelectric power generator for agricultural power supply using renewable solar energy. The use of thermoelectric modules instead of photovoltaic panels was justified. Based on the dependence of the generated power on the temperatures of the hot and cold circuits of the thermoelectric module, there was chosen the generator type of the thermoelectric module. (Conclusions) The hybrid system with a solar concentrator and a thermoelectric generator can be considered as an alternative to a traditional electric thermal diesel generator power supply system, since thermoelectric modules have recently been increasingly recognized by specialists in various fields of technology. The specific power of 42 thermoelectric modules with the area of 0.23 square meters is 1173 watts, which exceeds the specific power generated by a single-crystal photovoltaic panel with the area of 1.62 square meters, producing 166 Watts per square meter, which makes thermoelectric modules competitive with photovoltaic panels.

A Novel Arc-Shaped Lightweight Magnetic Coupler for AUV Wireless Power Transfer

The underwater wireless power transfer (UWPT) technology provides a feasible way to solve the problems of the traditional power supply method of the autonomous underwater vehicle (AUV). The magnetic coupler is the most essential component in the wireless power transfer system. Its configuration determines its applicable scenarios, and its parameter design and optimization will directly affect the system's overall output power and efficiency. In this article, an arc-shaped underwater wireless power transfer magnetic coupler is proposed, which is suitable for AUV's curved shell. Especially, the proposed novel magnetic coupler utilizes Fe-based nanocrystalline alloy soft magnetic material as the magnetic core. Both volume and weight of the receiver are reduced compared with the traditional Mn-Zn ferrite material. Fe-based nanocrystalline alloy material provides a novel design idea for the magnetic coupler on electrical equipment with special-shaped shell due to its flexibility. A prototype of the UWPT system for 320 mm diameter AUV is built, and it can transfer 3 kW power in the experiment with a dc–dc efficiency of 91.9% at the forward maximum output power point. Compared with the structure with ferrite core, the volume of the proposed structure is reduced by 41.1%, and the weight is reduced by 42.6%, so that the expected effect has been achieved.

Intelligent Substation Integrated Power Supply Research

As a necessary power source for substations and other important power-using places, substation power supply system provides working power for important loads such as control devices, relay protection, communication equipment and fire security systems. This paper addresses the problems of low operation efficiency, high human resource consumption and insufficient safety guarantee of the traditional power supply system, and proposes a solution for the integration of AC and DC in intelligent substations, which realizes the integration, intelligence and networking of the power supply system, improves the overall management level of the power supply system and the continuity of power supply, and has certain reference value for the design and application of the integrated power supply system in the future.

Autonomous and Programmable 12-W 10-kHz Single-Cell Li-Ion Battery Tester

Portable electronics like laptops are ubiquitous nowadays and they depend on batteries for power. Unlike traditional power supplies, batteries have limited capacity, cycle life, power capability, and other restrictions. To improve battery performance or select the best battery for an application, engineers need to accurately extract the battery’s parameters through experiments. Existing battery testers often fall short in current flexibility, accuracy, and battery voltage range and thus cannot accommodate all the necessary experiments and different battery types with a single setup. In this article, a 12-W battery tester using linear charger/discharger and bipolar power supply is proposed. The tester can provide programmable current profile up to 3.3 A and 10 kHz with a wide battery voltage range to accommodate for different battery types. The tester can also regulate battery voltage and perform constant voltage charge/discharge. A prototype is implemented, and the testing capabilities are demonstrated with common battery experiments using a commercial 18650 cylindrical battery. The experimental results show the tester’s excellent current accuracy and flexibility.

Positive sequence pilot impedance protection of AC tie line based on MMC-HVDC system

MMC-HVDC has the characteristics of limited amplitude, controlled phase angle and unequal positive and negative sequence impedance. Therefore, the fault characteristics of flexible direct system and AC power grid tie line are quite different from traditional synchronous power supply, which may affect the performance of AC power grid sudden variable protection. Therefore, a new AC protection method based on positive sequence current sudden variable impedance is proposed. The results show that when an in zone fault occurs, the direction of current sudden changes at both ends is the same, and the positive sequence impedance may approach the line impedance; When an out of area fault occurs, the current abrupt variables at both ends have opposite directions and equal sizes, and the positive sequence impedance is much greater than the line impedance. Based on the above characteristics, the criteria of fault start up and fault type are constructed. The simulation results show that the protection method can realize fault discrimination quickly and reliably.

Research on reliability evaluation of complex distribution network considering N-1 verification

With the rapid development of power system, the distribution network structure is gradually mature and the connection situation is more complex. The traditional distribution network reliability calculation method can not accurately calculate the reliability index of complex distribution network. Based on the traditional simple power supply reliability evaluation method of radial distribution network, this paper completely considers the influence of circuit breaker, tie switch, branch line, standby transformer and other equipment, and puts forward an improved network equivalence method model. The model first treats the complex distribution system in layers, and then gradually equates it into a simple radial distribution network to calculate the reliability of the system. At the same time, this paper analyzes the distribution network with multi connection structure in a provincial capital city. The results show that this model simplifies the complexity of distribution system reliability calculation, improves the accuracy and speed of reliability calculation, and more truly reflects the reliability of actual distribution system.

The invention relates to an intermediate frequency power supply fast start and digital phase locked loop control technology

Intermediate frequency induction heating is widely used because of its low energy consumption and high thermal efficiency, but the speed of traditional intermediate frequency power supply is slow and its frequency tracking accuracy is limited. In order to maintain the resonant state of the load during the working process of the induction heating power supply and realize the automatic frequency tracking control during the working process. The frequency tracking of the 40kW intermediate frequency power supply is researched, and a method of combining the resonant frequency automatic identification algorithm and the digital phase locked loop frequency tracking control method is proposed. MATLAB simulation and experiment show that the system based on this control method can save the time of searching the load resonance frequency in the initial stage of the power supply, improve the frequency tracking speed, accelerate the dynamic response speed of the system, avoid the failure of frequency lock, and play the role of fast and stable startup.

A survey on development and prospect of wind turbines virtual synchronous control technology

The ongoing energy revolution has led to the gradual replacement of traditional synchronous generators by renewable enecorresponding authorrgy. This transformation of power generation mode reshapes power system dynamics and poses many challenges to reliable and efficient grid operation. With the continuous improvement of the penetration level of renewable energy represented by wind power in the power system, the synchronous mode of wind turbine will gradually become one of the main modes of system synchronization. In the case of coexistence of multiple synchronization modes, the synchronization mechanism of the whole power system will be fundamentally changed; at the same time, due to the response characteristics of wind turbine to the frequency and voltage dynamics of power grid and the traditional power supply, the synchronous mode of wind turbine will gradually become one of the main modes of system synchronization The frequency and voltage stability of power system also faces new challenges. The virtual synchronous generation technology can make the grid connected inverter simulate the operation mechanism of step generator and provide an effective method to solve the above problems. In this paper, the main technical routes to realize virtual synchronous control of wind turbines are summarized. From the aspects of stability analysis, control system optimization, performance analysis and evaluation, the research and engineering status of virtual synchronization technology in wind turbines are introduced, and the problems to be solved and technical requirements are prospected.

Free Switching Control Strategy for Multi-Operation Modes of Multi-Port Energy Router in Distribution Area

For the distribution area with a high penetration rate of new energy, the traditional power supply system has some problems, such as a single form of power supply and low utilization of new energy. Because the multi-port energy router can realize the interconnection and complementation of multiple energy forms, it has become the key piece of equipment in the hybrid AC/DC distribution area. Nevertheless, restricted by the existing control strategy, the performance of the energy router in complex operation mode switching and coordinated control still needs to be further improved. To address this issue, the free switching control strategy is proposed in this paper. Firstly, the topology and model of the multi-port energy router are designed and established. Secondly, the operation mode of the system is analyzed, and the control strategy of each port is designed. Then, a reference power calculation method suitable for multi-mode operation is derived. Based on this, the control strategy does not need to be changed when operation modes are switched. Furthermore, the extended state observer is introduced to track and compensate for the new energy disturbance, which can improve the power quality of the system. Finally, the simulation and experimental results show that the proposed control strategy of the multi-port energy router can realize flexible and controllable power transmission among various modules in the distribution area and the free switching of multi-operation modes without changing the control strategy.

Fault location method of active distribution network based on graph theory and matrix algorithm

In view of the large scale distributed power distribution network, distribution network from the traditional single main transformer power supply system becomes more complex broken power supply network, the trend of the distribution network flow and network frame produced change, failure fault feature information of great change, the traditional distribution network fault location method can not accurately obtain the location of the fault zone, the low accuracy of fault location, the error bigger problem a new fault location method of active distribution network combining graph theory and matrix was proposed. According to the knowledge of graph theory, the distribution network is simplified to topology diagram and described in the form of matrix, and then the fault judgment matrix is obtained through a series of matrix addition operation, and the type of fault interval can be identified accurately and quickly by combining the fault criterion table. The simulation results show that this method is simple in principle, fast and effective in criterion, suitable for the flexible operation mode of active distribution network structure, can accurately and quickly determine the fault segment, and can meet the requirements of complex distribution network fault location.

A Linear-Motor Type HTS Flux Pump With Pumped Current Exceeding 640 A

In this paper, we present the fabrication and performance of a linear-motor type flux pump with a pumped current larger than 640 A. This high-temperature superconducting (HTS) flux pump can be used for magnetic resonance imaging (MRI) magnets and HTS electric machines. We use the flux pump to charge 10 superconducting closed-loops, and show the tested results of pumping current under different applied frequencies and magnetic field amplitudes. This flux pump device can output direct current larger than 640 A at 77 K. The output of this flux pump equals to a DC power source with low output voltage and high output current. Comparing with the traditional power supply of the same rated current, the size of this HTS flux pump is much smaller, while it also eliminates the harmful metal current leads that cause heat leakage. We show that, by increasing the length of the travelling wave region of this flux pump, there is no limit to the output of the current output, which can reasonably reach the kilo-ampere level. The purpose of this paper is to test the reliability of the methodology for the large current HTS flux pump.

Research on Distribution Network Reliability and Power Supply Soft Self-healing

The reliability of distribution network is an important index to ensure high-quality power supply. In this paper, the FMEA table is established based on the traditional power supply mode consequence analysis method, and the network topology after power supply isolation is determined by querying the table according to the power supply information. Then, the control mode of VSC is adjusted according to the VSC control strategy under different power supply conditions. Finally, through network reconfiguration and island operation, the continuous spatiotemporal power grid topology power supply restoration optimization model is established. On this basis, this paper combines sequential Monte Carlo method to evaluate the reliability of continuous spatiotemporal power grid topology, and illustrates the reliability evaluation difference caused by the difference of distribution network topology information.

Optimal microgrid power supply system for Nigerian detached communities: Environmental impact and energy cost criteria


 
 
 Climate change is a major contemporary global challenge. For developing countries like Nigeria, further challenge is poor power supply. Traditional power supply strategy has been through fossil-fuel based macrogrids. While most developed countries are replacing some macrogrids with renewable energy based microgrids, developing countries like Nigeria still maintain the status quo. This study intends to contribute to knowledge in the management of climate change and power supply in Nigeria through the adoption of microgrids as power supply strategy. In the study, data collected from a detached energy consuming community in Nigeria was used in a simulation using HOMER software for five different scenarios of energy resources combination, based on environmental impact and energy cost criteria. Results indicate that microgrids combining solar photovoltaic (SPV) and grid connection with battery energy storage (BES) are best in on-grid detached communities while microgrids combining diesel generators and SPV with BESare good for off-grid communities.
 
 

Research on Model Predictive Control Strategy of Converter in Building DC Power Supply System

The popularization of distributed renewable energy, the change of end-user load charACteristics, and the requirements of energy conservation and environmental protection have brought great challenges to the traditional AC power supply. Compared with AC power supply, DC power supply is widely concerned because of its powerful energy-saving advantages. Building electricity demand fluctuates greatly, and various power loads are frequently switched, which requires a higher demanding for the dynamic response capability. Based on switched system theory, this paper proposes a switched control method for building dc microgrid converter. The outer voltage loop adopts PI control and the inner current loop adopts predictive current control. The switched control model of the converter is established and the optimal switched rate is designed. An experimental platform based on SiC MOSFET is built for verification. The switched frequency is 50KHz, which verifies the effectiveness of the control strategy.

New approaches to the implementation of information and technical methods for the prevention of emergencies as a result of fire in conditions of damage to the power supply of emergency response systems

The paper proposes the development of new approaches to the creation of emergency response systems using non-traditional power supplies in the event of damage to traditional power supply systems.The main idea of the work is the formation of integrated approaches to alternative methods based on the phenomenon of acoustic emission (AE) using an unconventional power source based on film solar cells on flexible substrates. The creation of photoconverters based on thin films from a variety of materials and compounds is a promising direction in the development of solar energy. Unfortunately, the efficiency of these photoconverters is not yet high enough, but the cost of equipment for their creation, and hence the cost of instrument structures, is already quite acceptable.The investigated solar cells were obtained by the method of thermal vacuum evaporation using a UVN67 vacuum unit with modified internal equipment.After manufacturing, solar cells (SCs) were investigated under standard laboratory conditions adopted for the study of solar cells for ground-based use, i.e. in the AM 1.5 mode with a luminous flux power of 100 mW / cm2 and a temperature of 25 ° C. To study degradation processes in such solar cells after measuring the initial parameters The solar cells were placed in a sealed plastic box and kept for 4 years at a temperature of 15-25 ° СChecking the elements demonstrate high degradation resistance, which provides general requirements for the material and the conditions for its creation promising for use as unconventional sources of power supply for emergency response systems and ensuring the use of information and technical methods for preventing emergency situations as a result of fire in conditions of damage to the power supply of emergency response systems.

New Principle of Pilot Protection Based on Kendall’s Rank Correlation Coefficient

Affected by the control strategy after MMC failure, the fault current on the converter side of the AC line interconnected with the MMC is significantly different from the fault characteristics of the traditional power supply in amplitude and phase. The new fault current characteristics lead to the inapplicability of the traditional longitudinal current phase differential protection. In order to solve the problem of the applicability of relay protection, a new principle of longitudinal protection based on Kendall’s rank correlation coefficient is proposed. After the AC line fails, the Kendall grade correlation coefficient of the calculated current on both sides is calculated to distinguish the internal and external faults. Simulations are carried out on the RTDS platform, and the results show that the proposed protection principle can reliably distinguish between internal and external faults and has the ability to withstand transition resistance under various control reference values.

A High-Precision and High-Efficiency PMSM Driver Based on Power Amplifiers and RTSPSs

A novel topology based on linear power amplifiers (PAs) and real-time sinusoidal voltage-adjustment power supply systems (RTSPSs) for a permanent magnet synchronous motor (PMSM) drive system is proposed in this article. Here, PAs are applied to achieve high-precision motor drive control and minimize the motor torque ripple and harmonic loss caused by nonlinearities of the inverter in traditional space vector pulsewidth modulation. Meanwhile, in order to improve the conversion efficiency of PAs, the traditional dc power supply system of PAs is replaced by the RTSPSs, which is based on the wide-band-gap devices. The experimental results show that the efficiency of PAs in the motor system is increased from 58.88% to 79.25% and the fluctuation of the motor speed at a given speed of 2 r/min is reduced from 27 to 0.5 r/min.