煤矿用稀土永磁无刷直流电动机驱动电路设计

在研究煤矿用稀土永磁无刷直流电动机原理的基础上,设计电动机的驱动和保护电路。根据无刷直流电动机的工作原理,采用绝缘栅双极型晶体管（IGBT）作为电动机逆变单元的核心元件,使用专用集成驱动芯片VLA517—01R为核心搭建IGBT的驱动保护电路。驱动电路和控制电路-~f．q采用高速光耦隔离,避免了控制电路对驱动电路的干扰,保证了系统的可靠运行。通过试验证明,所设计的电路驱动能力强、稳定性好,在过流情况下能可靠地关断IGBT,并输出故障反馈信号。     

一种小型垂直轴风力发电机控制器设计

介绍了一种小型低速垂直轴风力发电机的控制器。该控制器以ATMEGA8535为控制核心,实现的功能包括恒压充电、转速检测、过流保护和工况显示等,主要针对家庭和野外露营使用。该控制器采用了简单的转速检测算法,在保证检测精度的前提下实现了控制程序的简化。充电电路由PWM控制IGBT形成软开关,再配合BUCK电路构成直流开关电源,对蓄电池进行恒压充电。采用Matlab/Simulink搭建模型,对PWM控制IGBT形成的软开关、BUCK电路和PID算法进行了仿真,结果证实该控制器设计合理,对今后该领域的深入研究具有指导意义。     

基于光伏系统IGBT的驱动及保护研究

本文介绍了驱动电路的设计原则和方法,分析了IGBT的几种典型驱动电路,并对IGBT的保护电路进行了探讨。     

晶闸管调功器的一种数字化触发电路

针对电阻炉超温、过流、缺相等故障的保护、报警及显示功能,提出一种新型的晶闸管数字化触发电路,介绍了该触发电路硬件系统的构成及工作原理,并对软件编程进行了论述。     

高压共轨ECU中保护电路的研究

对保护电路的概念及其分类进行了详细的介绍,结合目前的高压共轨系统,对电子控制单元(ECU)中用到的保护电路进行了深入的研究,设计出了执行器的短路保护电路,在实验室模拟了执行器短路情况下的过流现象,体现出了保护电路对ECU的保护作用,分析了保护电路的电路原理,并对电源系统的保护电路进行了分析.     

对两种过压保护电路的比较分析

经过比较分析,认为采用过压继电器GYJ的过压保护电路比采用辅助发电过流继电器FLJ的过压保护电路可靠性高.     

高精度加速器超导磁铁电源的研究

针对超导磁铁对电源的要求,提出了基于Buck Chopper电路的多相多重化的电源拓扑结构,采用IGBT为卸能开关来实现失超快速保护,分析了其工作原理.按该方案研制了一套高精度加速器超导磁铁电源,进行了严格的测试,结果表明,该方案满足了同步加速器超导磁铁对电源的高要求.     

空调IGBT器件电路应用可靠性研究

变频空调控制器中IGBT作为PFC电路的开关器件,其应用可靠性要求很高。本文结合电路应用分析和器件异常形貌分析,总结出IGBT器件在电路应用过程中常见可靠性应用建议和异常形貌对应总结。过程中的分析和结论对空调IGBT器件应用设计和异常分析具有一定指导意义。     

400W太阳能高压钠灯电子镇流器的研制

针对太阳能高压钠灯电子镇流器的特点和高压钠灯在高频下的缺陷,设计了一种基于廉价驱动芯片SG3525A为基础的新颖太阳能高压钠灯电子镇流器,采用频率调制技术消除了声共振。并且设计了可靠的启动电路及过流、过压和异常保护电路,且能实现恒功率控制,最后给出了实验结果。     

单相光伏并网逆变器电参数检测系统研究

准确检测光伏并网逆变器电参数,既可提高逆变器的控制速度和精度,又可在过流、过压、欠压等情况下迅速关断开关管,保护逆变器并提高其安全性。文章根据光伏并网逆变器对电参数的检测要求,以DSP芯片TMS320F2808为核心,由线性光耦HCNR201、霍尔电流电压传感器等器件构成检测电路、保护电路,设计了单相光伏并网逆变器电参数检测系统,并在1.5 kW高频隔离型光伏并网逆变器上应用。试验结果验证了该检测系统的可行性和可靠性。     

风电系统的无功功率与电网电压稳定

论述了风电容量在占局部电网相当比例时,风电机组的无功功率调整与电网电压之间的关系,对于定速和变速风电机组的运行特性做了分析,提出了在需要做无功功率调整时风电机组应能满足的特殊要求。     

New energy power generation-wind power generation

This paper introduced the status quo of wind power and wind power generation technology. Focusing on the introduction of wind power generating system ibrational self-consistent field（VSCF）, program implementation included Alternating Current （AC）-Direct Current （DC）-AC conversion system, magnetic field modulation generator system, doubly-fed generator system etc. Among these, doubly-fed generator system is the trend. Where to build the wind farm is very important, so a perfect site is needed. Wind power generation will have a bright future. As long as the wind power can be linked to the grid in large scale.     

Output power control for large wind power penetration in small power system

Nowadays, wind turbine generator (WTG) is increasingly required to provide control capabilities regarding output power. Under this scenario, this paper proposes an output power control of WTG using pitch angle control connected to small power systems. By means of the proposed method, output power control of WTG considering states of power system becomes possible, and in general both conflicting objectives of output power leveling and acquisition power increase are achieved. In this control approach, WTG is given output power command by fuzzy reasoning which has three inputs for average wind speed, variance of wind speed, and absolute average of frequency deviation. Since fuzzy reasoning is used, it is possible to define output power command corresponding to wind speed condition and changing capacity of power system momentarily. Moreover, high performance pitch angle control based on output power command is achieved by generalized predictive control (GPC). The simulation results by using actual detailed model for wind power system show the effectiveness of the proposed method.     

Output power variations with solar power satellites

The first comprehensive evaluation of output power variations expected from Solar Power Satellites is presented. The various factors are classified in a two tier manner as: deterministic (either periodic or non-periodic) and statistical (either constant with system life or changing with life). The largest variations are due to seasonal periodic factors, namely variations in the solar constant (± 3.3 per cent) and a solar illumination variation with the photovoltaic array held perpendicular to the orbit plane (± 4.2 per cent). Other key factors delineated which are being quantified presently include power reductions due to microwave power tube failure and silicon solar cell radiation damage, while multiple shadowing of adjacent power stations in geosynchronous orbit and rectenna structural factors and combining efficiency variations are representative of areas that need further study.     

Microthermophotovoltaic power generator with high power density

A promising energy source for portable MEMS devices, microthermophotovoltaic (micro-TPV) power generator, is described in this paper. The system mainly consists of a micro SiC combustor, and a GaSb photovoltaic (PV) cell array and a simple nine-layer dielectric filter, with a volume of about 3.1 cm³. When the flow rate of H₂ is 4.2 g/h, and H₂/O₂ ratio is 0.7, the system is able to deliver 3.06 W electrical power, the open-circuit voltage and short-circuit current are 2.31 V and 1.74 A, respectively, the result is a power density of about 1.0 W/cm³ (1 MW/m³). The effect of all kinds of factors on the performance of the micro-TPV system is also discussed in this paper.     

A hybrid power source for pulse power applications

Portable 12 V power supplies are used extensively for communications and power tool applications. These devices demand fast response times of the power supply. Fuel cells are generally best suited to continuous power applications and require an initial warm-up period, although they offer the prospect of increased operational duration over a battery for a given weight of portable system. This paper investigates the combination of specific energy performance from the fuel cell system with the specific power and response time of the battery. Two separate hybrid systems have been developed and tested; a planar, 20-cell, polymer electrolyte membrane fuel cell (PEMFC) stack together with either a lead–acid or nickel/cadmium battery; and a conventional 20-cell, bipolar, PEMFC stack. Both systems have been tested under pulse-load conditions at temperatures between −20°C and +40°C, and for comparison, the individual components have undergone similar tests. The hybrid systems have successfully operated continuously for several weeks under load profiles that the fuel cell alone could not sustain.     

Wind power and market power in competitive markets

Average market prices for intermittent generation technologies are lower than for conventional generation. This has a technical reason but can be exaggerated in the presence of market power. When there is much wind smaller amounts of conventional generation technologies are required, and prices are lower, while at times of little wind prices are higher. This effect reflects the value of different generation technologies to the system. But under conditions of market power, conventional generators with market power can further depress the prices if they have to buy back energy at times of large wind output and can increase prices if they have to sell additional power at times of little wind output. This greatly exaggerates the effect. Forward contracting does not reduce the effect. An important consequence is that allowing market power profit margins as a support mechanism for generation capacity investment is not a technologically neutral policy.     

Got power? [power engineers recruitment]

This paper discusses the different factors that can help to ensure that the future demand for power engineers will be met. These factors include the articulation of a compelling mission, development of a comprehensive strategy, execution of supporting tactics, and demonstration of leadership.