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风电并网对系统运行的影响和对策

Integration of Wind Power into Power Systems and Market Operations – Impact & Solution

胡明 Ming Hu

运行规划 (Operation Planning)

系统运行及可靠性 (O & R)

阿尔伯塔省电力运行机构(AESO)

2

阿尔伯塔省电力工业概况Alberta’s Electric Industry

• 最大负荷 (Peak load)：9,775 MW

• 年负荷系数 (annual load factor)：80%

• 装机容量 (Installed Capacity)：12,368 MW

• > 280台发电机组 (generating units)

• ~200电力交易商 (Wholesale market participants)

• > 21,000 km 输电线 (Transmission line)

• 2对外联络线 (Interties)：与BC省780MW；与 Sask.省 150 MW

BC

Alta.Sask.

煤电 Coal 5,893 MW燃气电厂 Gas 4,895MW

其它 Other214 MW

风电 Wind523 MW

水电 869MW

49%

38%

7% 4% 1%

Coal Gas Hydro Wind Other

主要风电项目 开发地区 (Primary

region)

> 11,000 MW 风电项目意向 (Wind power Interest)

300

KM

3

风电大规模并网对系统运行带来的挑战The System Operation Challenge of Large-Scale

Wind Power Integration

• 如何应对风电出力变化和不确定性How to handle the variability and uncertainty in System Operation

–理解风电出力的变化规律 ( 风电出力变化研究 )

Understand the wind power variability (Wind power variability study)

–理解风电出力的不确定性 ( 风电出力预测试点项目 )

Understand wind power uncertainty (Wind power forecast pilot project)

–理解和评估对系统运行的影响 ( 系统影响分析 , 1)

Understand and assess the potential impact on system operation (System Impact study, phase-1)

–评估潜在的系统应对措施及手段 ( 系统影响分析 , 2)

Assess potential mitigation solutions (System Impact study, phase-2)

–应对措施的实施 ( 发展风电的市场及运行框架 )

Solutions implementation (Market & Operation Framework)

4

理解风电出力的不稳定性Understand the wind power variability

• AESO 和风电行业合作，完成了 “阿尔伯塔风电出力变化研究”

AESO work with wind industry, contracted GENIVAR (Phoenix Engineering) to conduct “Alberta wind power variability study”

• 研究结果提供了 2004 年风电出力全年每分钟的仿真结果 / Provided simulated minute-to-minute wind power data for the whole year (2004)

– 基于 2004 年气候测量数据，未来风电发站方案及风电场模型 / Based on measured meteorology data across southern Alberta of potential future wind farms and wind power production simulation model

– 4 个未来风电发站方案 / For 4 scenarios (~250MW, ~900MW, ~1500MW and ~2000MW)

250MW 为 2004 年已有规模，用于模型验证 / The 250MW was the existing wind power scenario, for the purpose of wind power production simulation model validation

– 为下一步的 “风电的系统影响”提供必要的基础和数据 / The data was required and used later for AESO “Wind power system Impact studies”

• 研究的主要结论 : 风电出力的不稳定随着发展规模的增加而增大 , 但由于分布的分散互补性，并非按比例增大。 / A key conclusion of this study: The wind power variability does increase with the wind power development level, but not proportionally due to diversification

5

理解风电出力的不稳定性 (2) – 分散互补性 Understand the Variability of Wind Power (2) – Diversification

• 不同分布的风电场出力不稳定性的叠加 – 分散互补的影响The combined variability of different wind farms – Diversification impact

– 不同分布的风电场出力不稳定性的叠加不是简单的算术叠加，而是向量叠加，向量的方向取决于不同风电场的相关情况。The combined variability (random nature) is the vector-sum of each individual variability other than simple-sum

– 完全正相关 相互独立 完全反相关 positive correlate independent negative correlate

• 空间分散 / 时间互补 (Diversification: Space / Time)– 对短时出力变化互补明显 平滑效应平滑效应 / / more smoothing effectsmoothing effect for short-term

variability

– 对长期出力变化互补性减低 接力效应接力效应 ( 持续增减 ) / / less smoothing effectsmoothing effect and more relay effectrelay effect for long-term variability (Ramping issue)

– 取决于风场的位置分布和风向 / Also related with location distribution of wind farms and wind directions

6

理解风电出力的不确定性 – 风电出力预测试点项目Understand the Uncertainty of Wind Power (1) - Forecasting Pilot Project

• 试点三种不同的预测方法 ，为期 1 年 / Trial three very different forecasting methods over a one year period:

• AWS Truewind (US)• WEPROG (Denmark)• Energy and Meteo (Germany)

• 分别针对 4 个不同地理气候条件的地区 4 different geographic terrains / wind regimes in Alberta

• 每小时提供未来 1-48 小时的平均风速，矗立及变化 / T-1 to T-48 hours forecasted refreshed hourly (w/s, MWs, ramp rate)

• 7 个现有风场， 5 个未来风场 / 7 existing and 5 future facilities to represent geographic diversity and future expansion

• 统一的风场气象数据收集 / On-site Met Data Collection by GENIVAR

• 独立的结果分析 / Independent analytical analysis from ORTECH Power

Funded by Alberta Electric System Operator

Alberta Energy Research Institute

Alberta Department Of Energy

7

理解风电出力的不确定性 (2) – 预测误差实例Understand the Uncertainty of Wind Power (2) - forecast error example

Day Ahead Forecasts at 7am

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时间误差Phase Error

误报False Alarm

变化率误差Ramp Rate

漏报Miss

8

理解风电的不确定性 (3) Understand the Uncertainty of Wind Power - (3)• 不确定性不等同于变化 / Uncertainty is different than Variability

– 不确定性只是无法预测的变化－预测误差 Uncertainty is only the unpredictable variability – forecast error

• 风电出力预测的相对误差高于负荷预测 / The relative degree of uncertainty of wind power is bigger than load based on today’s forecast capability

– 1 日前预测 : 负荷一般 1-3% ，风电 >10% (100%????)

Day-ahead forecast: ~1-3% error for load vs. >10% for wind power

• 准确预测风电出力变化有难度 / The prediction of wind power ramping is challenging

• 常用的预测误差指标，例如 : 平均 | ％误差 | 、方差等不适用 / The standard accuracy metrics used to describe forecast performance may not be applicable or meaningful to system operations, such as MAPE, RMSE because they can suppress ramping signals

– 需要制定新的预测误差指标，能够全面反映幅值、相位、误报、漏报及变化趋势误差 / Need some accuracy metrics that can describe not only magnitude error, but also phase error, false-alarm rate, capture-rate, ramping rate error

– AESO 制定了基于出力变化事件的幅值 / 相位误差图　 AESO developed an changing-event-based magnitude/phase accuracy chart to assess and understand wind power forecast capability

9

理解风电出力变化及不确定对系统运行的影响Understand and Assess the System Impact of Wind Power Variability and Uncertainty (1)

• 系统的关键是要维持实时的系统供需平衡 / System operation involves maintaining a constant balance between supply and demand

• 包括 4 个重要环节 / Four key aspects to achieving system balance

– 预测维持系统供需平衡的平衡能力 / Ability to forecast the balancing requirement

– 保证充足的系统资源 / Adequate system resources for this requirement • 容量，备用及调节控制能力 / Supply sources (generation) and control

sources (ancillary services)

– 相应的运行规程 / Operating policies and procedures

– 实时的运行决策 / Real-time operating decisions

• 风电出力变化及不确定对以上 4 个环节均有影响 / The variability and uncertainty of wind power may impact all of the above aspects

• 2 种分析方法：理论分析，仿真分析　Two ways to analyze impact: statistical and simulation

10

　　　　　　　　　　

运行预测 Operation

Forecasting

系统影响分析方法 / System Impact Analysis Framework

其它变化及不确定Other variability

& uncertainties

系统整体变化及不确定

System Overall

variability & uncertainties

负荷变化及不确定Load variability & uncertainties

风电变化及不确定Wind Power variability & uncertainties 区域控制误差

ACE

性能指标 1CPS1

性能指标 2CPS2

输电能力越限OTC Violation

基于理论的统计分析Statistical analysis

实时调度模拟 / Real-time 　Dispatch simulation

衡量各种变化的指标Variability indices

发电备用调度模拟结果 Simulation of Energy market, Regulating reserve & Tie flow

模拟的性能指标Simulated results of: ACE, CPS2OTC violations

非计划潮流UnscheduledInterchange

运行性能

评估

Perform

ance

Assessm

ent

•潮流交换•发电调度•备用调度

•Interchange scheduling•Energy market dispatch

•Ancillary services

各种运行规程Operating policies

& procedures

11

统计分析实例： 1 小时的变化分析Statistic analysis example: 1 hour variability

负荷与风电出力相互独立The variability of load and wind power are independent

随着风电的增加，风电出力对系统整体的变化及不确定的影响从可忽略到共同主导As wind power increase, the wind power variability can increase the overall system variability to a level that can not be ignored and more dominate

12

统计分析实例： 4 小时的系统不确定性影响Statistic analysis example: 4 hour uncertainty

风电不确定性对系统整体不确定性的影响随电规模增大而增大 / The wind power uncertainty can have ignorable or significant impact on overall system uncertainty depend on the penetration level and timeframes

风电增加对系统不确定性的影响更加显著Wind power uncertainty could increase faster than load as level increase

13

统计分析实例：风电出力持续变化分析Statistic analysis example: Changing event-based analysis

250MW 900MW

1500MW 2000MW

随着风电规模的增大There will be more, longer and faster persistent system changing as wind penetration increase

对调节跟踪能力有限的系统带来压力 It put pressure on system with limited ramping capability

幅度 1400-1600MW 历时 5-6 小时系统持续变化发生 4次 / there is 4 changing events with duration of 5-6 hours and ramp-down magnitude of 1400-1600MW

14

Step 2: 每分钟仿真1-minute simulation

仿真分析，方法及假设条件Simulation-based analysis, Methodology and Assumption

Step 3: 计算对运行性能的影响 / Calculate impact to system performance criteria

•CPS2•OTC violation

Step 1: 发电调度决策仿真　 Determine Energy Market Dispatch (Every 20 minutes)

未来 20 分钟调度决策Energy Market Dispatch for next 20 minutes

当前调度误差Current Supply-Demand Imbalance (ACE)

预期负荷变化Expected Load change

潮流交换计划Interchange Schedule change

风电出力预测Expected wind generation (persistent forecast …)

调度有效性准则出力调度幅度应 >20MWDispatch validationMW threshold, if imbalance within +/- 20MW, no instruction is made and any imbalance is handled by RR or ACE

计算调度出力变化，考虑系统应变速度和相应时间Calculate the Energy market movement with ramping capability limitation and response delay

计算调度出力与实际需求间的误差 / Calculate the mismatch between supply and demand

计算平衡出力误差所需的调节备用 / Calculate required regulating reserve movement to balance the mismatch 10% of MW range/min

无法平衡的误差即为“区域控制误差” Remaining mismatch is simulated ACE

递归迭代

算法

Recu

rsive Iteration

Alg

orith

m

15

基于仿真的分析，仿真模型分析界面Simulation-based analysis, Simulation model GUI

Load

风电出力Wind power

仿真调度出力Simulated EMD

历史调度出力Historical EMD

潮流输出限制Export Limit

潮流输入限制Import Limit

潮流计划Interchange Schedule

仿真潮流交换Simulated Interchange

历史区控误差 HIST. ACE

仿真区控误差SIM. ACE

调节备用容量RR range

仿真备用调度SIM. RR dispatch

仿真区控误差SIM. ACE

仿真性能指标越限SIM. CPS2 Violation

余度Ld

-Ld

20-min moving minimum off-schedule输电可靠性备用

TRM

System data

quality Tag

Wind power data

quality Tag

16

系统影响分析 1 – 结论System Impact Study phase-1 conclusions

• 4 个风电开发方案 ( 包括 1 个当前方案，验正模型 ) ，用以确定风电增加对系统的增量影响。所有３个风电发展方案都有性能指标越陷的问题4 wind development scenarios (existing + 3 future), to identify the incremental impact effect. All 3 growth scenarios studied resulted in one or more performance violations.

• 分析结果显示风电增加和系统运行控制性能指标下降和传输能力越限的因果关系 / There is an observable relationship between increased wind power development, Decreased CPS2 performance and Increased OTC violations.

• 大规模风电并网运行将需要制定、实施应对措施以保证系统的安全可靠运行It is highly likely that mitigating measures will need to be developed and implemented in order to integrate large scale wind power and maintain the reliable and safe system operation 　

17

调查评估各种针对出力变化和不确定性的应对措施 – 系统影响分析２Investigate and Assess Different Mitigation solutions of Power Variability and Uncertainty (10) – System Impact Study phase-2

• 有效的应对措施包括： / Effective mitigating measures for wind power integration are:

– 风电出力预测 / wind power forecasting

– 增加发电调度的可控变化能力 / More energy market ramping capability

– 增加的调节备用或追踪备用容量 / additional regulating or following service

– 风电出力管理 / wind power management

• 无效的应对措施 / The ineffective mitigating measures are:

– 负荷的自然增长 / Increases in AIES load

– 增加调节备用的调节速度 / Increasing the regulating reserves ramp rate

18

风电出力变化及不确定应对措施的实施 – AESO 发展风电市场 & 运行框架Solutions of Wind Power Variability and Uncertainty- AESO Market and Operation Framework (MOF) for Wind Power Integration (1)

• 原则：在保证系统安全可靠运行和市场公平和效率的同时尽量增加风电的并网To integrate as much wind power into the Alberta system as is feasible without compromising system reliability or the fair, efficient and openly competitive operation of the market.

• 目的是建立一个稳固的基础作为通过实践不断改进完善的起点The intent is to develop a solid starting point from which to continuously improve

• 建立适当的机制使得市场力量能够优化解决方案 / To set up proper mechanism to allow the market force lead to solutions optimization

• 在获得合理风电出力预测的前提下，运行人员可以制定计划采用以下措施吸收预测的分风电发电 / The premise – If the System Operator receives a reasonable forecast of wind power generation, then they can establish an operating plan to accommodate the forecast wind energy by using the following resources / tools:

– 预测 / Forecasting– 发电调度排序 / The Energy Market Merit Order– 调节备用 / Regulating Reserves– 跟踪备用 / Wind Following Services– 风电出力管理 / Wind Power Management

19

市场运行框架 – 具体工作AESO MOF for Wind Power Integration – Work streams

• 市场 & 运行规则 / Market & Operating Rules

• 风电出力管理 / Wind Power Management

• 风电出力预测 / Wind Power Forecasting

• 额外的辅助服务的预测和获取 / Additional Accessory Services Forecast / Procurement

• 系统运行辅助软件工具 / System Operator Tools

• 接入系统 / Interconnection

– 接入排序管理 / Queue Management Practices

– 接入系统标准 ( 出力管理、预测等 ) / Standards for Interconnection (Power Management & Forecasting Requirement)

• 电源发展方案预测方法 / Generator Scenario Development Methodology

• 输电网规划 / Transmission Planning

• 鼓励分散多样性 / Diversity

20

具体工作之一运行辅助软件工具MOF Work Stream (1) – Operator tools

– 分析工具 / Engineering tool

• 用以在设计、测试各种可能实施的运行规程 / To design and test protocols, procedures before implementation into OPPs

– 实时运行的辅助工具 / Real-time system operation tool

• 用以帮助有效管理 / To effectively manage:

• 各种规程的实时操作 / The procedures in the real-time

• 保证复杂运行决策的有效、一致和透明度 / complicated real-time system operation with Efficiency, Consistency and Transparency

– 提供知识、信息、经验共享和不断完善的共享平台Common basis for knowledge sharing, experience and continuous improvement

21

运行辅助软件工具的功能框架　 Work stream – Tools: Architecture

各种分析评估／ Operation assessment•To balance between Supply and Demand•To assess the situation & risk of:

• System Ramping Capability• Supply Shortfall issue• Supply Surplus (Zero-offer) issue• Minimum technical output issue• OTC violation issue

Actual Generator output (PI) Energy & RR

Dispatch logs (EMS)

系统状态 / System Status

Load Forecast (EMS)

Wind Power forecast

InterchangeSchedule or

Forecast (EMS)

Uncertaintyanalysis

系统的变化系统的变化

System System ChangesChanges

ATC limits(IPCTCP)

Energy Market Merit Orders

(EMS)

RR Merit Orders

(ETS or EMS)

Generator Ramping

Characteristic

Additional Services

Wind Power Management

系统发电和控制系统发电和控制System Supplies System Supplies

& Controls& Controls

运行决策 / Operation decisions• Energy Market Dispatch• Trigger Supply surplus process• Trigger Supply shortfall process• Additional Service Dispatch• Wind Power Management

22

问题和交流？ Question or Comments?

相关信息： Related Information can be found at:

• 阿尔伯塔风电出力的变化研究 / Alberta Wind Variability Study

– http://www.aeso.ca/gridoperations/13847.html

• 阿尔伯塔风电的系统影响分析 1 / AESO Wind Power System Impact Study - Phase1

– http://www.aeso.ca/downloads/Incremental_Effects_on_System_Operations_with_Increased_Wind_Power_Penetration_rev_2_3.pdf

• AESO 风电系统影响分析模型简介 / AESO Wind Power System Impact Simulation Model Presentation

– http://www.deq.state.mt.us/Energy/Renewable/DispatchSimulationModel_v4.pdf

• 阿尔伯塔风电的系统影响分析 2 / AESO Wind Power System Impact Study – Phase2

– http://www.aeso.ca/downloads/AESO_Phase_II___Wind_Integration_Impact_Studies_final_20060718.pdf

• 阿尔伯塔发展风电市场及运行框架 / AESO Market & Operation Framework for Wind Power Integration

– http://www.aeso.ca/gridoperations/13030.html

• AESO 风电出力预测试点项目 / AESO wind Power Forecast Pilot Project

– http://www.aeso.ca/gridoperations/13825.html

• AESO 风电运行及市场信息周报 / AESO Weekly Wind Power Operation and Market Reports

– http://www.aeso.ca/gridoperations/14246.html

• 更多信息 / For more information:

– http://www.aeso.ca/gridoperations/13902.html

– ming.hu@aeso.ca, (403)539-2503