1、光伏逆变器中英文对照资料外文翻译文献中英文对照资料外文翻译文献光伏逆变器的发展及优势结构与工作原理逆变器是一种由半导体器件组成的电力调整装置,主要用于把直流电力转换成交流电力。一般由升压回路和逆变桥式回路构成。升压 回路把太阳电池的直流电压升压到逆变器输出控制所需的直流电压;逆变桥式回路则把升压后的直流电压等价地转换成常用频率的交流电 压。逆变器主要由晶体管等开关元件构成,通过有规则地让开关元件 重复开-关(ON-OFF),使直流输入变成交流输出。当然,这样单纯 地由开和关回路产生的逆变器输出波形并不实用。一般需要采用高频 脉宽调制(SPWM),使靠近正弦波两端的电压宽度变狭,正弦波中 央的电
2、压宽度变宽,并在半周期内始终让开关元件按一定频率朝一方 向动作,这样形成一个脉冲波列(拟正弦波)。然后让脉冲波通过简 单的滤波器形成正弦波。逆变器不仅具有直交流变换功能,还具有最大限度地发挥太阳电池性能的功能和系统故障保护功能。归纳起来有自动运行和停机功 能、最大功率跟踪控制功能、防单独运行功能(并网系统用)、自动 电压调整功能(并网系统用)、直流检测功能(并网系统用)、直流 接地检测功能(并网系统用)。这里简单介绍自动运行和停机功能及 最大功率跟踪控制功能。1、自动运行和停机功能早晨日出后,太阳辐射强度逐渐增强,太阳电池的输出也随之增大,当达到逆变器工作所需的输出功率后,逆变器即自动开始运行
3、。进入运行后,逆变器便时时刻刻监视太阳电池组件的输出,只要太阳 电池组件的输出功率大于逆变器工作所需的输出功率,逆变器就持续 运行;直到日落停机,即使阴雨天逆变器也能运行。当太阳电池组件 输出变小,逆变器输出接近0时,逆变器便形成待机状态。2、最大功率跟踪控制功能太阳电池组件的输出是随太阳辐射强度和太阳电池组件自身温度(芯片温度)而变化的。另外由于太阳电池组件具有电压随电流增大 而下降的特性,因此存在能获取最大功率的最佳工作点。太阳辐射强 度是变化着的,显然最佳工作点也是在变化的。相对于这些变化,始 终让太阳电池组件的工作点处于最大功率点,系统始终从太阳电池组 件获取最大功率输出,这种控制就是
4、最大功率跟踪控制。太阳能发电系统用的逆变器的最大特点就是包括了最大功率点跟踪(MPPT) 这一功能。工作环境与要求:1 光伏逆变器要求具有较高的效率。由于2011年太阳电池的价格偏高,为了最大限度地利用太阳电池,提高系统效率,必须设法提高 逆变器的效率。2光伏逆变器要求具有较高的可靠性。2012年光伏发电系统主要用于边远地区,许多电站无人值守和维护,这就要求逆变器具有合理 的电路结构,严格的元器件筛选,并要求逆变器具备各种保护功能, 如输入直流极性接反保护,交流输出短路保护,过热、过载保护等。3光伏逆变器要求直流输入电压有较宽的适应范围,由于太阳电池的端电压随负载和日照强度而变化,蓄电池虽然对
5、太阳电池的电压具 有重要作用,但由于蓄电池的电压随蓄电池剩余容量和内阻的变化而 波动,特别是当蓄电池老化时其端电压的变化范围很大,如12V蓄电 池,其端电压可在10V-16V之间变化,这就要求逆变器必须在较大 的直流输入电压范围内保证正常工作,并保证交流输出电压的稳定。4光伏逆变器在中、大容量的光伏发电系统中,逆变电源的输出应为失真度较小的正弦波。这是由于在中、大容量系统中,若采用方波 供电,则输出将含有较多的谐波分量,高次谐波将产生附加损耗, 许多光伏发电系统的负载为通信或仪表设备,这些设备对电网品质有 较高的要求,当中、大容量的光伏发电系统并网运行时,为避免与公3、切换型并网光伏发电系统所
6、谓切换型并网光伏发电系统,实际上是具有自动运行双向切换的功能。一是当光伏发电系统因多云、阴雨天及自身故障等导致发电 量不足时,切换器能自动切换到电网供电一侧,由电网向负载供电二 是当电网因为某种原因实然停电时,光伏系统可以自动切换使电网与 光伏系统分离,成为独立光伏发电系统工作状态。有些切换型光伏发 电系统,还可以在需要时断开为一般负载的供电,接通对应急负载的 供电。一般切换型并网发电系统都带有储能装置。4、有储能装置的并网光伏发电系统有储能装置的并网光伏发电系统:就是在上述几类光伏发电系统中根据需要配置储能装置。带有储能装置的光伏系统主动性较强,当 电网出现停电、限电及故障时,可独立运行,正
7、常向负载供电。因此 带有储能装置的并网光伏发电系统可以作为紧急通信电源、医疗设 备、加油站、避难场所指示及照明等重要或应急负载的供电系统。优势1)利用清洁干净、可再生的自然能源太阳能发电,不耗用不可 再生的、资源有限的含碳化石能源,使用中无温室气体和污染 物排放,与生态环境和谐,符合经济社会可持续发展战略。(2)所发电能馈入电网,以电网为储能装置,省掉蓄电池,比独立太阳能光伏系统的建设投资可减少达35% 45%,从而使发电成本大为降低。省掉蓄电池避免了蓄电池的二次污染,并可提高系统的平 均无故障时间。(3)光伏电池组件与建筑物完美结合,既可发电又能作为建筑材料和装饰材料,使物质资源充分利用发挥
8、多种功能,不但有利于降低 建设费用,并且还使建筑物科技含量提高,增加”卖点5(4)分布式建设,就近就地分散发供电,进入和退出电网灵活,既有利于增强电力系统抵御战争和灾害的能力,又有利于改善电力系 统的负荷平衡,并可降低线路损耗。(5)可起调峰作用。联网太阳能光伏系统是世界各发达国家在光伏应用领域竞相发展的热点和重点,是世界太阳能光伏发电的主流发 展趋势,市场巨大,前景广阔。The development and advantage of photovoltaic inverterStructure and working principieInverter is a kind of the s
9、emiconductor device com posed of po wer adjusting device, mainly used for the de power into ac power. Generally the booster circu让 and inverter bridge circuit composition. Booster circuit the solar cell de voltage booster to the inverter output control the de voltage; Inverter bridge circuit is the
10、booster of de voltage equivalent to convert common frequency ac voltage. Inverter is mainly com posed of transistor and switch component is formed, and through the regular to switch element repeat on-off (ON - OFF), make de input into ac output Of course, this simply by on or off circuit to produce
11、the inverter output waveform is not practical. General need to adopt high-frequency pulse width modulation (SPWM), close sine wave the voltage across the width change narrow, central sine wave voltage width broaden, and in the half period always let the switch element according to certain frequency
12、in a direction action, so that form a pulse wave train (quasi sine wave). Then let the pulse wave through the simple filter form sine wave.Inverter not only has direct communication mapping function, but also has maximize solar cell performance function and system fault protection function. To sum u
13、p automatic op eration and shutdown function, maximum power tracking control function, prevent run separately function (grid system), automatic voltage regulation function (grid system), the de detection function (grid system), the de grounding detection function (grid system). Here introduce automa
14、tic op eration and stop function and maximum power tracking control function.1automatic op eration and stop functionThe sunrise in the morning, the sun radiation intensity increasing, solar cell output has increased, when the inverter to the output power, the inverter automatically start running. En
15、ter after the op eration, the inverter and every minute mon让oring solar cell module, as long as the output of the solar cell module the output power of the inverter is greater than the output power, inverter is continuous running; Until sunset stop, even 讦 the day of overcast and rainy inverter can
16、also run. When solar cell module output diminish, inverter output close to zero, inverter and standby state formation.2the most high power tracking control functionThe output of the solar cell module with solar radiation intensity and solar cell module itself ternperature (chip temperature) and chan
17、ge. Plus, because of solar cell module has the voltage with current increase and the characteristics of the decline, and therefore there are can get the most high power best working point Solar radiation intensity is changing, obviously the best working point is also changing. Relative to these chan
18、ges, always let solar cell module of the working point in the maximum power point, the system always from the solar cell module for maximum power output, this control is the most high power tracking control. Solar power system with inverter is the biggest characteristic of including the maximum powe
19、r point tracking (MPPT) this function.Working environment and requirements:1.Photovoltaic inverter requirements w让h high efficiency. The 2011 solar cell price is on the high side, in order to make the best use of solar celt and enhanced the system efficiency, must try to imp rove the efficiency of t
20、he inverter.2.Photovoltaic inverter are required to have high reliability. 2012 pv power generation system is mainly used in remote areas, many power station unattended and maintenance, which requires the inverter instruments have reasonable circu让 structure, strict components selection, and require
21、ments for inverter instruments of various protection functions, such as input de polarity meet anti protection, ac output short circuit protection, heat, overload protection, etc.3.Photovoltaic inverter for de input voltage has a wide application range, becauset he sun battery terminal voltage with
22、load and sunshine intensity and change, battery although to solar cell voltage plays an important role, but due to the battery voltage w让h battery residual capacity and the change of resistance and fluctuation, especially when battery voltage across the age range change is very big, such as 12 v bat
23、tery, the terminal voltage can be in 10 v 16 v changes between, which requires the inverter must be in large de input voltage range ensure normal work, and ensure the stability of the ac output voltage.4.Photovoltaic inverter in medium and large capacity of photovoltaic power generation system, the
24、output of the inverter power supply should be distortion smaller sine wave. This is due in large capacity system, if you use the square wave power supply, the output will contain more harmonic component, the high harmonics will generate additional loss, a lot of photovoltaic power generation system
25、load for communication or instrument equipment, the equipment to power quality have higher requirements, and large capacity of photovoltaic power generation system p arallel op eration, to avoid and pu blic electricity from the grid pollution, also requires inverter output sine wave current. Devel o
26、p ment prosp ectPhotovoltaic (PV) grid generation system is solar energy components preduced by de grid inverter converted to conform to the mains power requirements of the alternating current (AC) after this direct access to public power grid. Photovoltaic (PV) grid power system has a large, centra
27、lized grid power station are generally national power station, the main characteristic is the power to direct delivery to the power grid, the grid unified deployment to the user power supply; Also have distributed small grid generation system, especially PV power generation system, building integrat
28、ion is the mainstream of the combined to the grid.1 current grid photovoltaic power generation systemA current grid photovoltaic power generation system: when the solar photovoltaic system generated electricity plenty, but will be surplus power supply into the public power grid, the grid power suppl
29、y (sell electric); When solar pv system provides power shortage, the power to load power supply (buy electric). Due to the power supply to the power supply with the oppos让e, so called counter-current photovoltaic power generation system.2 no current grid photovoltaic power generation systemNo curren
30、t grid photovoltaic power generation system, solar photovoltaic power generation system even if the power is not enough power supply to the public, but when the solar photovoltaic systems, power supply is insufficient the public power grid to the load power supply.3switching type parallel in photovo
31、ltaic power generation systemThe so-called sw让ching type parallel in photovoltaic power generation system, is actually has to be automatic op eration two-way switch function.One is when the photovoltaic power generation system for cloudy day of overcast and rainy, and their own fault that generating
32、 capacity is insufficient sw让cher can automatically switch to the side of the power supply, the power grid to the load power supply; The second is the power for some reason reality power, photovoltaic system can automatically switch power and photovoltaic system separation and became an independent photovoltaic power generation system working condition.Some switching type photovoltaic power generation system, still can be in when to disconnect the power supply for general load, connect the power supply to emergency load. General switch type combined to th
copyright@ 2008-2022 冰豆网网站版权所有
经营许可证编号:鄂ICP备2022015515号-1