An Interactive Real Time Control Scheme For the Future Grid Operation

Transcription

1 An Interactive Real Time Control Scheme For the Future Grid Operation Taiyou Yong China Electric Power Research Institute May 15,

2 Disclaimer The views expressed in this presentation are completely personal opinions. They do not necessarily represent those of China Electric Power Research Institute or the State Grid Company of China. 2

3 Outline 1 The Future China Grid Operation 2 The Operational Challenges 3 The Interactive Control Scheme 4 Summary 3

4 The Future of China Electric Grid Increasing Demand: ~10 Billion =1.8 x MWh@2013 UHV Transmission: 1000KV AC: 3H,3V 800DC: 11 The Flow of Electricity 2020 Plan of UHV Transmission Grid EV:5M Vehicles DG:~50GW Capacity DR: 10-15% Peak Load Renewable Generation ~200GW Wind and ~100GW PV ~20% of 1600GW Installed Capacity Smart Grid Technologies (EV, ES, DR etc.) Source: Public Information 4

5 The Future of China Grid Operation The Possible Scenario in 15~20years Conventional Generation Coal:~40% Gas:~5% Hydro:~20% Nuclear:~15% Renewable ~15% Transmission Grid UHV:Backbone Transmission,Multiregional Interconnection Flexible Transmission:VSC-HVDC/FACTS Energy Flow Information Flow Conventional Load ~85% Distributed Generation Microgrid ~5% Control Center Flexible Load DR ~8% EV ~2% ES ~5% 5

6 An Interactive Grid Operation Hydropower Hydropower Thermal power Intermittent Flexible Thermal power supply Pumped storage Biomass energy power Gas turbine Flexible transmission and distribution Source Grid Load Control center Conventional load Conventional load Flexible load Controllable load Demand response Micro-grid EV Storage Source-Grid Grid-Load Source-Source Source-Load Flexible grid Interaction Source: China EPRI Report 6

7 The Incremental Operation Process Capacity Operating Spinning AGC Frequency Reserves Reserve Reserve Droop Variability & Uncertainty (MW) Inertia Governor Response Regulating Units Hydro Simple-Cycle GT Energy Storage Combined Cycle Intelligent Distribution Devices Warm ST Demand Response Interruptible Load Cold ST 1 day 4 hr 15 min 5 min 10 s 0 s Source: R. Philbrick Ø The Emerging Smart Grid Technologies may play a significant role in the real time operation. 7

8 The Operational Challenges-1 Lack of sufficient load following capability P Enlarged PL Load-Ren. Gen. Load-Ren. Gen-Flex. load PG_U Real Time Imbalance Load PG Gen. Schedule AGC Capability PG t PG_D Ø Shall explore the flexibility of load to supplement the LF capability 8

9 The Operational Challenges-2 Difficult to control vast load components directly. Convent. Generators Distributive Random Large Ren. Gen. Direct, Precise Control Unable to detect accurately Unable to control precisely Flexible Loads (DR EV ES) Dist. Gen, Microgrid Control Center Distributed Control Leading Control Autonomous Response Ø Shall adopt the distributed intelligent control 9

10 The Flexibility of Load With DG, EV, ES and DR, load becomes much more flexible. FERC 2009 DR Report Assess the DR potentials in different sectors, different mechanisms In 2019 DR Capacity ~188GW ~20% peak load China EPRI study for Northern China Grid in 2011 showed DR capability ~13% Fast DR (<20minutes) can provide regulation, spinning reserve and non-spin reserve. LBNL Study for California showed that many devices are capable for DR Fast DR is about 20% of the full DR potentials. Applied to North China Grid the Fast DR is about 2.7% of its peak load in Fast DR Source:FERC, LBNL, and China EPRI Reports 10

11 The Complexity of Load Control Load flexibility is an indispensible part of grid control in the future. Load individuals are in large quantities, great varieties, diverse behaviors, disperse locations. DR is self-motivated and benefit driven. If allowed to respond freely, the load will become random, unorderly, and difficult to predict. Need to schedule and control cooperatively in different scales of time and space. Proper scheme and mechanism can lead the load to respond in favor of the safe and efficient operation of system. 11

12 An Agent-based Interactive Control Structure Inter-Area Coordinator Coordination Layer Area Control 1 Area Control 2 Area Control 3 Area Control n Area Control Layer Wind Power Suppliers PV Power Suppliers Generation Companies Composite Gen-Load Users Flexible Load Providers Distribution Utilities Interaction Layer Ø Establish necessary communications and mechanisms to support interactions. 12

13 A Leading Interactive Control-1 Control Performance Requirements Wind power Agents Agent Interactio n Relationship Multi-Agent Environment P L Rolling 5- minute Leading Control P L Area AGC Control Solar Power Agents Flexible Load Agents Distribution Agents Large Load Agents Area Control Security Constraints Load- Following generators Ø Initiate look-ahead responses to mitigate the AGC Control. 13

14 A Leading Interactive Control-2 The Optimal Control Problem The Leading Control Sequence X(t) X L (T) Stochastic Constraints: Deterministic Constraints: X L (t 0 ) X L (t 2 ) X L (t 1 ).. Coordination Constraints: t 0 t 1 t 2 T t X ={ P,V, Frequency, prices or other } 14

15 A Leading Interactive Control-3 Cooperative Control Analysis: An Area Interactive Control Model N x& = f( x ) + a ( t) Γ( t)( x x ), i = 1,2, L, N i i ij j i j= 1 j i f( x i ) + µ i (t) the agents characteristics functions MAS Simulation Study: Power System Simulator Price, f or P target P MAS(NetLogo) N j= 1 j i a () t Γ()( t x x ) ij j i the coordination between agents µ i (t) the control variables Find the coordination in interaction! Incorporate the intelligence in response 15

16 Summary With the development of smart grid, the electric grid becomes more flexible in generation, transmission, distribution and consumption, especially in the demand side. Interactions between Source-Grid-Load will be the future of grid operations. With appropriate mechanisms, the flexibility of load can be explored to compensate the generators for mitigating the volatility and randomness of renewable generation. Distributed and intelligent control schemes is proposed to support the interactive grid operations. A leading interactive control scheme is proposed. The look-ahead real time dispatch is expected to initiate the autonomous response of flexible loads. Besides the active power, the interactive control scheme utilizes more system information in dispatch and control, such as price, frequency etc. Some communications shall be established to support the interactive control. 16

17 Thank you! 17