大型太阳能发电模式转变_通过现代电力电子技_省略_获取更多电能_创造可控的太阳能
张宇 2009 年加 入美国 赛康科 技公司 ,Michael Levi 是 美 国 赛 康 科 技 公 司 全INNOVATION & TECHNOLOGY创新与技术大型太阳能发电模式转变— 通 过 现 代 电 力 电 子 技 术 获 取 更 多 电 能 , 创 造 可 控 的 太 阳 能公 用 发 电 设 施美国赛康科技公司大中华区销售副总裁美国赛康科技公司全球市场部高级总监张宇 Michael Levi 摘 要 随着从数十兆瓦到数百兆瓦的分布式发电系统的建立,在这种新的模式下因为大量发电部件的增加,曾被认为是可以忍耐的问题和挑战被高度放大化和问题化。作为系统中唯一的智能组件, 只有逆变器能够对发电装置的两个部分 — 组件到逆变器和逆变器到电网互联点实行高级指令和控制操作。关键词 逆变器 大型太阳能电厂 系统性能 电能产出 智能电网 最大功率点跟踪0 前言 光伏系统的其他独立部件也对促进整个系过去,太阳能电厂性能是通过两个独立的指标来衡量:一块太阳能电池板将光能转换为电能的效率和一台逆变器电力转换的效率( 通常指 CEC 效率 )。由于 太阳能发电系统规模已变得更大、更为复杂,新一轮价值波动的焦点就集中在如何寻找机遇提高关键系统性能上,这些机遇存在于组件的互相作用关系之中,存在于组件集成之后连接到电网作为稳定的产能资源之中。统性能提升,特别是对于大型太阳能发电装置,起到更明显和更迅速的作用。公用电力部门开始意识到,当太阳能发电装置被视为一个完整的集成系统而非一系列可被单独测量性能的连接组件时,太阳能可以是一个可靠的、高性能的能源。作为系统中唯一的精密电力电子设备,先进的中央逆变器增强了设备获得高质量电能的能力,改善了 DC 侧和 AC 侧的系统性能,并远程控制电厂和电网的互联点,从而使电力部门能够监控和管理整个系统性能,并把1 从组件到电网太阳能组件是太阳能系统中最耀眼太阳能作为可调度和可控制的电厂资产。担任大中华区销售副总裁,负责赛康在中国地区的销售和市场战略实施,拥有美国加最昂贵的部件,其价格可占到系统总成本 2 大型太阳能电厂面临的挑战 州州立大学萨克拉门托分校电子工程学士的 80% 以上。目前,领先的太阳能电池板技术光电转换 率在 10 %~25%之 间。太阳能光伏系统从太阳能电池板获取能量并传 送 到 电 网 或 电 力 用 户 的 方 式 ——决 定了 整个系统的电能产量,反过来 ,也 定 义了系统性能和盈利能力。虽然太阳能电池组件的革新对持续增长的太阳能应用和行业本身来说是必不可少的,但是太阳能网址: www.chinaygny.cn 58 随着从数十兆瓦到数百兆瓦的分布式发电系统的建立,在这种新的模式下因为大量发电部件的增加,曾被认为是可以忍耐的问题和挑战被高度放大化和问题化。在兆瓦级发电系统的一个阵列中需要对成百乃至上千的组串和组件进行控制以获得最大的系统性能,使分布式发电系统能够为智能电网输送电力。把每产出一兆瓦电能需约 8 英亩学位和美国斯坦福大学电子工程硕士学位。球市场部高级总监。美国赛康科技公司是公用事业级光伏逆变器供应商,为分布式电力市场提供可再生能源并网发电解决方案。Satcon |www.satcon.com 地址:中国上海市遵义路 100 号虹桥上海城A 幢 2902 - 3 室 邮编: 200051创新与技术 INNOVATION & TECHNOLOGY 变器已经受到了电力设计者们的欢迎,因为这些逆变器把阵列分隔成若干部分,在组串级或者组件级就可以实施MPPT 优 化 。它 们 的 价 值 在 于 具 有 组 串级 或 组 件 级 优 化 电 力 生 产 的 能 力 ,提 高组 件 性 能 ,并 在 各 自 管 理 的 范 围 内 隔 离那些有可能对整个阵列造成负面影响的 低 性 能 组 件 。每 一 个 组 串 都 由 自 己 的MPPT 电 路 管 理 ,成 百 上 千 的 太 阳 能 组件 不 需 要 再 被 连 接 到 同 一 个 MPPT 上进行输出电能平均化 。5 下一 代 太阳 能 发电 技 术的 催 化剂太阳能发电领域的下一个飞跃将是通过结合应用两种逆变器的优点做到无论身处何方均 能 实 现 本 地 优 化 。但 是 这并不仅仅是简单地创造一个性能增强的 电 流 穿 越 装 置 ,而 是 在 电 力 电 子 架 构( 32376 平方米)太阳能电池板、所需组件之间的乘数效应和对于临界判定点的增加作为考虑因素的话,就不难理解何为整体系统性能必须被优化管理以实现最大盈利。来自于太阳能组件的直流电转换为最终用户可使用的交流电。专有的最大功率点跟踪( MPPT)技术帮助逆变器全天能量产出最大化,提早以及延长系统一天中的工作时间,从而可以在不断变化和间断的条件设 计 有 多 种 选 择 的 今 天 ,能 提 供 先 进 的电 网 互 联 能 力 ,使 公 用 电 力 部 门 可 以 远程 控 制 电 厂 AC 侧 和 DC 侧 , 无 论 使 用哪 种 电 池 板 ,整 个 系 统 都 拥 有 良 好 的 监控 、管 理 和 性 能 改 善 能 力 。 Satcon 光 伏3 解决实际问题收获更多电能 下,使阵列在 “ 最佳状态 ” 下运行。 逆 变 器 产 品 中 的 Solstice 系 列 逆 变 器随着下一波大规模太阳能发电浪潮的袭来,所面对的主要问题是如何获取整个系统真实性能并在系统寿命周期内保持该性能水平稳定。很明显,实际发电情况和实验室控制环境下的测试结果是存在差异的。真实工作的环境呈现出多变性,例如电池板不匹配、面板弄脏、损坏、遮挡或风沙、气候或其他各种实验室中不会出现,但是在真实变化的环境中对系统正常运行时间和最高电能捕获的能力存在巨大影响的因素。解决的方法存在于系统架构之中。通过设计从组件到系统平衡部件再到电网的电力传输步骤,太阳能发电项目的设计者们在系统性能、电能产出、可靠性、安全性和因为逆变器在传统上 被 看 作 是 电流 穿 越 式 组 件 ,所 以 它 的 性 能 好 坏取 决于 能 效 转 换 量 。不 考 虑 逆 变 器 为 系统 带来 的 性 能 增 强 效 果 , 会 低 估 逆 变 器智 能性 。然 而 ,作 为 系 统 唯 一 的 智 能 组 件 ,只有逆变器能够对发电装置的两个部分 —— 组 件 到 逆 变 器 和 逆 变 器 到 电网互 联 点 实 行 高 级 指 令 和 控 制 操 作 。直 到最 近 , 大 型 太 阳 能 发 电 系 统 设 计 者不 得不在微型逆变器和中央逆变器中做出选 择 , 因 为 两 者 各 有 优 劣 。 对 于 大 型发电 装 置 而 言 ,普 遍 认 为 中 央 逆 变 器更 节约 成 本 、 更 高 效 。 中 央 逆 变 器 通 常 把一个 阵 列 作 为 单 一 资 源 来 管 理 。这 种方 式就 是 一 个 很 好 的 例 子 —— 它 在 阵 列 的DC 侧 和 AC 侧 都 设 有 两 层 结 构 , 进 行最优电能捕获和公用电网互联控制操作 。 Solstice ,一 个 分 布 式 的 能 源 管 理 系统 , 采 取 由 点 到 面 的 工 程 设 计 理 念 ,对阵 列 单 个 部 件 、系 统 中 央 管 理 器 、设 备故障和性能衰减毫秒反映时间等方面增 强 了 互 操 作 性 和 控 制 能 力 。 Solstice 对 组 串 级 的 管 理 通 过 将 MPPT 功 能 转移到阵列的子汇流箱来完成,其中DC- DC 转 换 器 按 一 个 特 定 输 出 电 压 把多 个 组 串 并 联 ,使 逆 变 器 能 够 一 直 处 于最佳运行状态 。电能质量方面实现了迅猛地发展,同时也 实 现 了 规 模 经 济 , 能 够 通 过 单 点 操作 对6 结束语增强了把太阳能电厂变为能够为智能电网提供服务的分布式能源系统的能力。系 统 进 行 监 控 、 管 理 和 维 护 。 但 缺 点是太阳能组件串联的方式迫使单个组件特 性 被 平 均 化 ,按 照 普 遍 的 阵 列 特性 生太阳能电厂结构设计和电网整合的技术进步不仅提高了电网的稳定性、使业主可以获得更高的电能和投资回报,而且也4 微型和中央逆变器:历史和未来 产 电 能 。 相 反 地 , 与 单 一 大 型 中 央 逆变重新定义了太阳能发电和行业未来走向的从传统上讲,逆变器的主要功能是把 器 不 同 , 使 用 多 个 小 型 逆 变 器 的 微型 逆观念和可能性。 (责编:罗增英)投稿邮箱: bianjibu86@126.com 59INNOVATION & TECHNOLOGY创新与技术The Changing Paradigm of Large-scale Solar Power Production — Harvesting more energy & creating a cont rollable solar utility asset through advanced power electronicsJim Zhang★ , VP Sales, Greater China, Satcon Technology Corporation Michael Levi ★ , Senior Director of Worldwide Marketing, Satcon Technology Corporation Abstract As multi-megawatt, distributed-generation systems from 10s to 100s of megawatts are being built, the issues and challenges that were once considered tolerable are substantially amplified and problematic in this new paradigm, given the sheer volume of contributingcomponents. As the only intelligent component in the system, the inverter is uniquely positioned to enable advanced command and control in both hemispheres of the installation, from the panels to the inverter and from the inverter to the grid interconnection point. Key words Inverter, Large-scale solar power plant, System Performance, Power Production, Smart Grid, MPPT 0 Foreword 1 From panel to grid the advanced central inverter enhances the Historically, two distinct and isolated areas of solar power plant performance were measured:a panel’s efficiencyin transforming Solar panels are the most visiBle andexpensive component in solar installations, accounting for upwards of 80% of costs.utility’ s aBility to harvest significantly higherlevels of power, improve system performance on Both the DC and AC side, and remotelyphotons into electrons and the efficiency ofan Leading panel technologies currently produce control the power plant and grid inverter as a throughput device— often Between 10% and 25% of consumaBle energy interconnection point, allowing the utilities toreferred toas CECefficiency. As solar systems from the photons they aBsorB. The way solar monitor and manage total system performance have grown in size and sophistication, the PVsystems harvest energyfromthe panel and and deploy solar as a dispatchaBle, focus for driving the next game changing deliver it to the grid— or consumer controllaBle power plant asset.waves of value have emerged in the form of interconnection point— determines total key system-wide performance opportunitiesthat exist at the nexus of componentinteraction and their respective integration onto the grid as a proper and staBle source of energyproduction. system power production, which, in turn,defines performance and profitaBility. While solar panel innovation is essential for the continued growth of solar energy use and the industry, other independent aspects of the2 Challenges facing large - scale solar power plants As multi-megawatt, distriButed- gene ration systems from 10s to 100s of megawatts are Being Built, the issues and challenges thatMore than simply competing for higher photovoltaic (PV) system need to Be leveraged were once considered toleraBle are CEC efficiency levels, which measures loss to drive even more significant and immediate suBstantiallyamplified and proBlematic in thisunder standardized laBoratory conditions, total system performance improvements, new paradigm, given the sheer volume ofunderstanding the total system— the especially for large-scale installations. contriButing components. Multi-megawatt underlying relationship Between the Utilities are now recognizing that solar power systems have anywhere from hundreds, tocomponents, the environments in which they can Be a reliaBle, high-performance energy hundreds ofthousands ofstrings and panels in operate, and optimally managing those resource once the installation is viewed as a a given array that need to Be controlled to components in relation to overall plantperformance, is critical toimprovingthe levels of power plant performance, uptime, andreliaBility. 网址: www.chinaygny.cn 60 fully integrated system as opposed to a series of connected components whose performanceis measured in isolation. As the only piece of sophisticated power electronics in the system, maximize performance and enaBle distriButed energy generation to power the smart grid. Factor an estimated eight acres of panels per production megawatt, the multiplier effect of创新与技术 INNOVATION & TECHNOLOGY dependent components and the proliferation of critical decision points, it is understandaBle why total system performance must Bemanaged optimallytoachieve profitaBility.3 Harvest more power By solvingreal- world challenges performance enhancements that it delivers.Yet, as the only intelligent component in the system, the inverter is uniquely positioned to enaBle advanced command and control inBoth hemispheres of the installation, fromthe panels to the inverter and from theinverter to the grid interconnection point. sides of the power plant, as well as enaBle visiBility,management,andimprovementofthetotal system, regardless of what panel is used.One example is Satcon’ s system, Solstice— a two-stage architecture on Both the DCand AC sides of the array, which delivers fine grainedpower harvesting and control with critical As the next wave of large-scale solar Until recently, large-scale designers had to utility ready grid interconnection. A approaches, the primary question is how to choose Between the micro-inverter and the distriButed energy management system, realize real-worldperformance gains of the central inverter, Both of which have engineered from the ground up, Solsticeentire system and maintain those levels over the system’s lifespan. Clearly, there is adifference Between real, delivered value, and laBoratory controlled test results. The real world presents variaBles such as panelstrengths and weaknesses. With regard tolarge-scale installations, central inverters are generally seen as more cost-effective and efficient. They traditionally manage the array field as a single energy source. This Brings enaBles interoperaBilityand control over everycomponent in the array, a central command center, and millisecond reaction time around faults and failures. String level management isaccomplished Bymovingthe MPPTfunction tomismatch, panel level soiling, damage, Both advantages of economies of scale and the array suB-comBiner Box, where DC to DC shading or Blown deBris, climate, and other variaBles not represented in a laBoratory, But factor heavilyon system uptime and aBility to offers a single point of failure to monitor, manage, and maintain. The downside is thatconnecting solar panels in series forces an converters Bus the paralleled strings at a constant output voltageenaBlingtheinverterto constantlyrunatitsoptimalpoint.harvest maximum amounts of energy in averaging of individual solar panel changing environments. The answer resides in characteristics to produce a common array 6 Conclusion the system’ s architecture. By addre ssingenergy flow processes from panel throughBalanceofsystem(BOS)components tothe grid,characteristic. Conversely, micro-inverters, the deployment of many small inverters asopposed to a single, large central inverter, Advances in solar architecture and grid integration are not only helping staBilize thegrid and deliveringsignificantlyhigher returnssolar project developers immediately achieve have gained popularity Because they on investment and power, But they are also vast improvements in system performance,power production, reliaBility, safety, andpower quality, while gaining advancedcapaBilities that turn solar plants into a distriButed energysource for a smart grid.disaggregate the array and perform MPPToptimization at the string or module level. Their value is in their aBility to optimize power production at the string or modulelevel, feeding higher performance at the redefining the perception and possiBility of Both solar power and the future path of the industry. ( Executive Editor: Luo Zengying )panel level, and isolating suB-par Jim Zhang is the VP of Greater China,4 Micro and central inverters: performance at a local level Before it Satcon, joined the company in 2009 to Behistory & future impacts the entire array. Each string is responsiBle for Satcon’ s sales and Traditionally, the inverter’ s primary managed with its own MPPT circuit and the marketing in China and implement the function is to convert DC power from solar outputs of hundreds or thousands of solar company’ s gloBal sales strategy. He panels into consumaBle AC power for end panels no longer need to Be a veraged By received a B.S. degree in Electrical users. Proprietary Maximum Power Point connectingthemtoone MPPT. Engineering from California State University, Tracking (MPPT) solutions help inverters Sacramento and an M.S. degree in maximize production throughout the day, 5 Thecatalyst for next generation solar Electrical Engineering from Stanford waking them up earlier and putting them toBed later, thereBy operating the array at its “ sweet spot” in varying and intermittentconditions. Because the inverter has traditionally Been viewed as a pass-through component,The next leap in solar field powerproduction is coming from harnessing the Best attriButes of Both inverters to achieve local optimization with gloBal control. But more than simply creating an enhanced pass-through device,powerelectronicarchitectureBecomingUniversity. Michael Levi is the seniordirector of Worldwide Marketing for Satcon Technology Corporation, a provider of utility scale, grid connected renewaBle energysolutions for distriButed power markets.Satcon | www.satcon.com its performance has Been Based on efficiency availaBle today offers advanced grid Address:Unit 2902-3, Tower A, Citymetrics. This undervalues the intelligence of the inverter By failing to measure the interconnection capaBilities that allowutilitiesto remotely control Both the AC and the DCCenter ofShanghai, 100 Zunyi Road,Shanghai 200051, P.R. China投稿邮箱: bianjibu86@126.com 61