Generation Expansion Planning

Transcription

1 Generation Exansion Planning Based on Multi-area eliability Exonential Analytic Model and Emission Control Lin Cheng singhua Univ. Generation Exansion Planning Considerationsrequirements of ower demands, installation caacities, loss of load robability (LOLP) levels, locations, and environmental limitations for emission controls Methods: exonential analytic model: the influences of installed caacity of each area and transfer caability of the flowgate lines on the generation system reliability of every single area; investment cost, O&M cost in objective function flowgate transmission limitations and emission control are used as constraints 1

2 Otimization Framework Considerations: Environmental constraints; eliability requirement; Locations; Load demand level; Coordination between generation installation and transmission ugrade Environmental Pollution in GEP China s ower industry Power demand level Investment Low efficiency in ower generation Air ollution is inevitably caused by coal units, not only sulhurdioxide (SO) and nitrogen-oxide (NOX), but also large amount of greenhouse gases. Sulhur-dioxide emission owing to environmental constraints in China is 1 million tons annually, actual emission in 6 is 5.9 million tons and sulhur-dioxide emission from fuel electric lant only has exceeded environmental caacity.

3 Coordination he roblem of coordination becomes more difficult under ower market deregulation. Generation exansion lanning involves decisions on location and caacity of new generation, which may lead to adding or relieving congestion in transmission lines, so transmission exansion may be executed due to generation exansion lanning (GEP) After transmission exansion, GEP should re-adjust to maximize investment revenues Methods A combined relationshi between reliability and generation & transmission coordination is illustrated through the exonential analytic model of multi-area system Coordination is solved by the exonential analytic model Environmental constraints are exressed as emission limits in each area. 3

4 Generation eliability elationshi between reliability and caacity Parameter solution / = A e C M / Ae C M ΔC / Ae C M ln M C = Δ C C Multi-Area Generation eliability Suose that transfer caabilities in interfaces are abundant enough with no transmission constraints, reliability levels of all areas are generation-dominant roblems. (n areas, m tie lines system) D1 ΔC D ΔC Dn ΔC = diag( 1,, K, n ) [ e, e Le ] = [ 1,, KKn ] ; = [ 1,, KKn ] ; ΔC =Δ [ C1, ΔC, KKΔCn ] D d11ld 1jLd1n M M M M M d Ld Ld M M M M M dn1ldnjldnn n n= i1 ij in he element dij means the influence factor of generation installed caacity change in area j on the reliability level of area i, i means reliability level of area i at the base case, C i means installed caacity change in area i. 4

5 Multi-Area Generation eliability Suose that there are abundant total generation installed caacity and transmission constraints influence ower interchange, then reliability levels of all areas become transmission-dominant roblems. 1 Δie Δie n Δie = diag( 1,, K, n ) [ e, e Le ] t11lt1j Lt 1m = [ 1,, KKn ] ; M M M M M n m= t i1ltijltim = [ 1,, KKn ] ; M M M M M tn1ltnjltnm Δie =Δ [ ie1, Δie, KKΔiem ] he element t ij means the influence factor of transmission caacity change in interface j on the reliability level of area i, ie j means transmission caacity change in interface j Multi-Area Generation eliability n areas, m tie lines system 1 1 ln ΔC 1 d11 d1j d1 n t11 t1j t ΔC 1m L L L L M ln MOMOM MOMOM C [ ] d n i1 dij din ti 1 tij t Δ = D ΔC = L L L L im Δie Δie 1 M MOMOM MOMOM Δie d n n1 dnj dnn tn 1 tnj tnm ln L L L L M ie n Δ m Samle Area A Area B A B A ΔC 1 +ΔC B A ln C 1 A d11 d1 t Δ 11 = ΔC d B 1 d t1 ln Δie 1 B 5

6 Otimization Model Cost-Benefit Function ransmission Constraints of Flowgate Environmental Constraints Insufficient ransmission Caacity Exansion Cost-Benefit Function Cost of Generation and ransmission Ugrade C = c n + c n Inv ij ij k k (, i j) k c ij : the cost of a transmission line in the i, j branch where n ij lines were added; c k : the installation cost of a candidate generation node k where n k generators were added. Oeration and Maintenance Costs CO& M = ( fu + ou) gu u: generating unit u; u f u : fuel cost for each unit of ower outut from the generating unit u; o u : O&M cost for each unit of ower outut from the generating unit u; g u : generation outut of unit u 6

7 Consumer Benefit An affine inverse demand function is assumed. he curve shows a general form of a demand function that is used in this aer and indicates the rice resonsiveness of the consumers: Node Price ($/MWh) α β = α / D D Demand hrough the integration of demand function, the consumer benefit can be calculated 1 B= αvdv βvdv ransmission Constraints of Flowgate For a change in real ower transaction between areas, say by t k,l, the change in transmission line quantity is ij. In case of generation exansion, suose load oint demand increment is L l, corresonding generation oint outut increases G k, i.e., t k,l = L l = G k. Δij Δij PDFij k, l = = = PDFij k Δt ΔG kl, k otal ower flows through the flowgate f must be less than the maximum value ( PDF G ) C ij k k f ij f k 7

8 Environmental Constraints For each region r of existing or new added generation installation, an uer bound for ollutant emission is imosed S K h g H a= 1,, 3 sa, u ra, s= 1 u Θ( r, s) a: emission ollutant tye (a =1 for sulhur-dioxide, a = for nitrogen-oxide, and a =3 for carbon-dioxide); s: tye of generation unit; K: the number of hours within the interval; : units set of tye belonging to region ; hθ s,a (,) rs : ollutant emission level for a unit of tye ; H r,a : uer bound on ollutant emission within region during interval. wo Models Constant Caacity Model: only generation exansion cost is included in investment function Min B c n C O& M k k k st.. = diag( 1,, K, n ) [ e, e Le ] D ΔC ΔC Dn ΔC 1 D thres r r= 1,, Kn ( PDFij Gk ) C k f ij f k S K hsa gu H a= 1,, 3, ra, = 1 u Θ( r, s) s Combined Model: generation shortage and insufficient transmission caacity Min B CInv CO& M st.. = diag(,, K, ) 1 n D1 ΔC+ 1 Δie D ΔC+ Δie Dn ΔC+ [ e, e L e ] n Δie thres r r = 1,, K n ( PDFij k Gk ) C f ij f k S K hsa, gu H ra, a = 1,, 3 s= 1 u Θ( r, s) 8

9 Five-Bus System In this system, the flows on lines 5-1, 4-1, and 4-3 have been selected as the lines that constitute a transmission flowgate. he total flow over these three lines is limited to 3 MW, there are no flow constraints on single lines; he caital cost er hour of adding extra caacity is assumed to be $5 er MW at each node; he oerating costs are given in able ; Coefficients of ollutant emissions are given in able ; Cost of transmission line is a constant value in this aer. Bus 5 Area 1 Area Flowgate Bus 1 Bus 4 Bus 3 Bus System Parameters ABLE I Generator Data Generator Bus 1 Bus 3 Bus 4 Bus 5 Caacity(MW) O&M Cost($/MWh) ABLE II Coefficients and Uer bounds for Pollutant Emission Pollutant Coefficients (g/mwh) Bounds (*1 3 kg/yr) Coal Oil Gas Bus 1 Bus 3 Bus 4 SO NO X CO

10 Constant Caacity Model D.931. = Area is a sink area in current state, so installed caacity in area does not imrove the reliability level in area 1, then d 1 =; Within the range of transmission caacity of the flowgate, increment of installed caacity in both areas will imrove the reliability level in sink area; due to d >d 1, installation in area may be slightly more effective to imrove the reliability level in sink area. Constant Caacity Model Case 1: reliability threshold of area is.4 hrs/yr; Case : reliability threshold of area is 4 hrs/yr; Case 3:.4 hrs/yr reliability threshold constrained caacity model with environmental constraints; Case 4: 4 hrs/yr reliability threshold constrained caacity model with environmental constraints Otimization esults Case Bus 1 Exansion (MW) Bus 3 Bus 4 Bus 5 Profit($) Case ,785 Case ,95 Case ,36 Case ,585 1

11 Combined Model I = caacity increment in flowgate will lead to imrovement in reliability level of sink area; Suose area 1 have sufficient installed caacity, so its reliability level doesn t change with flowgate caacity. Combined Model Case 5:.4 hrs/yr reliability threshold combined model with environmental constraints; Case 6: 4 hrs/yr reliability threshold combined model with environmental constraints Otimization esults Case Bus 4 Exansion (MW) Bus 5 ransmission Profit($) Case ,754 Case ,556 11

12 Conclusions Multi-area generation reliability exonential analytic model takes the couling influence between areas into account, and transmission caacity ugrade from the combined model has much influence on GEP. o make GEP more effective, environmental regulations from government requirement must be taken into account, test results show that emission control does limit outut of some units, then GEP must be adjusted accordingly. Coordination between GEP and transmission ugrade is imortant in multi-area systems. Generation of lower cost can be transferred through newly built transmission lines to make the otimal GEP. hanks 1