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Zadatak 9

Jakobijan Newton-Raphson-a, mreža od četiri čvora: rešen zadatak

Zadatak i rešenje: prof. dr Andrija T. Sarić

Analiza elektroenergetskih sistema, TF Čačak

Zadatak

Na slici je prikazan EES u kome su admitanse svih vodova jednake i iznose Y‾g=(1−j10)\ph{Y}^g = (1 - \mathrm{j}10) r.j.

  1. Izračunati elemente matrice Y‾BUS\ph{\boldsymbol{Y}}_{BUS}.
  2. Usvajajući čvor 1 za referentno-balansni izvršiti klasifikaciju preostalih čvorova na PQ i PV čvorove.
  3. Odrediti dimenzije Jakobijan matrice za proračun tokova snaga Newton-Raphson-ovom metodom.
  4. Izračunati vrednosti elemenata ∂(ΔP2)∂θ2\frac{\partial(\Delta P_2)}{\partial \theta_2}, ∂(ΔQ3)∂V3\frac{\partial(\Delta Q_3)}{\partial V_3}, ∂(ΔP4)∂V4\frac{\partial(\Delta P_4)}{\partial V_4} Jakobijan matrice u prvoj iteraciji proračuna tokova snaga Newton-Raphson-ovom metodom.
1V1 = 1,05 r.j.θ1 = 0°3SP3 = (0,4 + j0,05) r.j.2SP2 = (0,6 + j0,2) r.j.SG2 = (1,1 + jQG2) r.j.V2 = 1,05 r.j.4SP4 = (0,6 + j0,2) r.j.YgYgYgYgYg = (1 − j10) r.j.

Poznato

  • Gg=1G^g = 1r.j.
  • −Bg=10-B^g = 10r.j.
  • V1=1,05V_1 = 1{,}05r.j.
  • V2=1,05V_2 = 1{,}05r.j.
  • PG2=1,1P_{G2} = 1{,}1r.j.
  • PP2=0,6P_{P2} = 0{,}6r.j.
  • QP2=0,2Q_{P2} = 0{,}2r.j.
  • PP3=0,4P_{P3} = 0{,}4r.j.
  • QP3=0,05Q_{P3} = 0{,}05r.j.
  • PP4=0,6P_{P4} = 0{,}6r.j.
  • QP4=0,2Q_{P4} = 0{,}2r.j.

Rešenje

a.

Y‾BUS=GBUS+jBBUS=[2−1−10−13−1−1−1−13−10−1−12]+j[−201010010−3010101010−301001010−20]\begin{gathered} \ph{\boldsymbol{Y}}_{BUS} = \boldsymbol{G}_{BUS} + \mathrm{j} \boldsymbol{B}_{BUS} \\ = \begin{bmatrix} 2 & -1 & -1 & 0 \\ -1 & 3 & -1 & -1 \\ -1 & -1 & 3 & -1 \\ 0 & -1 & -1 & 2 \end{bmatrix} \\ + \mathrm{j} \begin{bmatrix} -20 & 10 & 10 & 0 \\ 10 & -30 & 10 & 10 \\ 10 & 10 & -30 & 10 \\ 0 & 10 & 10 & -20 \end{bmatrix} \end{gathered}

b.

Čvor 1:V1=1,05V_1 = 1{,}05, θ1=0\theta_1 = 0P1=?P_1 = ?, Q1=?Q_1 = ?SL čvor
Čvor 2:V2=1,05V_2 = 1{,}05, P2=PG2−Pp2=0,5P_2 = P_{G2} - P_{p2} = 0{,}5Q2=?Q_2 = ?, θ2=?\theta_2 = ?PV čvor
Čvor 3:P3=−Pp3=−0,4P_3 = -P_{p3} = -0{,}4, Q3=−0,05Q_3 = -0{,}05V3=?V_3 = ?, θ3=?\theta_3 = ?PQ čvor
Čvor 4:P4=−Pp4=−0,6P_4 = -P_{p4} = -0{,}6, Q4=−0,2Q_4 = -0{,}2V4=?V_4 = ?, θ4=?\theta_4 = ?PQ čvor

c.

n=4,2NPQ+NPV=2⋅2+1=5n = 4 , \quad 2 N_{PQ} + N_{PV} = 2 \cdot 2 + 1 = 5

Znači, Jacobian matrica je petog reda.

J=[∂(ΔP2)∂θ2∂(ΔP2)∂θ3∂(ΔP2)∂θ4∂(ΔP2)∂V3∂(ΔP2)∂V4∂(ΔP3)∂θ2∂(ΔP3)∂θ3∂(ΔP3)∂θ4∂(ΔP3)∂V3∂(ΔP3)∂V4∂(ΔP4)∂θ2∂(ΔP4)∂θ3∂(ΔP4)∂θ4∂(ΔP4)∂V3∂(ΔP4)∂V4∂(ΔQ3)∂θ2∂(ΔQ3)∂θ3∂(ΔQ3)∂θ4∂(ΔQ3)∂V3∂(ΔQ3)∂V4∂(ΔQ4)∂θ2∂(ΔQ4)∂θ3∂(ΔQ4)∂θ4∂(ΔQ4)∂V3∂(ΔQ4)∂V4]KL′HF′J = \overset{\boldsymbol{H} \hspace{12em} \boldsymbol{F}'}{\underset{\boldsymbol{K} \hspace{12em} \boldsymbol{L}'}{\left[ \begin{array}{ccc:cc} \frac{\partial(\Delta P_2)}{\partial \theta_2} & \frac{\partial(\Delta P_2)}{\partial \theta_3} & \frac{\partial(\Delta P_2)}{\partial \theta_4} & \frac{\partial(\Delta P_2)}{\partial V_3} & \frac{\partial(\Delta P_2)}{\partial V_4} \\[1ex] \frac{\partial(\Delta P_3)}{\partial \theta_2} & \frac{\partial(\Delta P_3)}{\partial \theta_3} & \frac{\partial(\Delta P_3)}{\partial \theta_4} & \frac{\partial(\Delta P_3)}{\partial V_3} & \frac{\partial(\Delta P_3)}{\partial V_4} \\[1ex] \frac{\partial(\Delta P_4)}{\partial \theta_2} & \frac{\partial(\Delta P_4)}{\partial \theta_3} & \frac{\partial(\Delta P_4)}{\partial \theta_4} & \frac{\partial(\Delta P_4)}{\partial V_3} & \frac{\partial(\Delta P_4)}{\partial V_4} \\[1ex] \hdashline \frac{\partial(\Delta Q_3)}{\partial \theta_2} & \frac{\partial(\Delta Q_3)}{\partial \theta_3} & \frac{\partial(\Delta Q_3)}{\partial \theta_4} & \frac{\partial(\Delta Q_3)}{\partial V_3} & \frac{\partial(\Delta Q_3)}{\partial V_4} \\[1ex] \frac{\partial(\Delta Q_4)}{\partial \theta_2} & \frac{\partial(\Delta Q_4)}{\partial \theta_3} & \frac{\partial(\Delta Q_4)}{\partial \theta_4} & \frac{\partial(\Delta Q_4)}{\partial V_3} & \frac{\partial(\Delta Q_4)}{\partial V_4} \end{array} \right]}}

d.

Pi=Vi2Gii+Vi∑j∈αi[Vj(Gijcos⁡(θi−θj)+Bijsin⁡(θi−θj))]\begin{aligned} P_i = V_i^2 G_{ii} &+ V_i \sum_{j \in \alpha_i} \Big[ V_j \big( G_{ij} \cos(\theta_i - \theta_j) \\ &+ B_{ij} \sin(\theta_i - \theta_j) \big) \Big] \end{aligned}
J11=∂(ΔP2)∂θ2=V2∑j=1j≠24Vj[−G2jsin⁡(θ2−θj)+B2jcos⁡(θ2−θj)]\begin{aligned} J_{11} &= \frac{\partial(\Delta P_2)}{\partial \theta_2} \\ &= V_2 \sum_{\substack{j = 1 \\ j \neq 2}}^{4} V_j \Big[ -G_{2j} \sin(\theta_2 - \theta_j) \\ &\qquad + B_{2j} \cos(\theta_2 - \theta_j) \Big] \end{aligned}
J11(0)=V2V1[−G21sin⁡(θ2(0)−θ10)+B21cos⁡(θ2(0)−θ1)]+V2V3(0)[−G23sin⁡(θ2(0)−θ3(0))+B23cos⁡(θ2(0)−θ3(0))]+V2V4(0)[−G24sin⁡(θ2(0)−θ4(0))+B24cos⁡(θ2(0)−θ4(0))]\begin{aligned} J_{11}^{(0)} = {} &V_2 V_1 \Big[ -G_{21} \sin(\overset{0}{\cancel{\theta_2^{(0)} - \theta_1}}) \\ &\qquad + B_{21} \cos(\cancel{\theta_2^{(0)} - \theta_1}) \Big] \\ &+ V_2 V_3^{(0)} \Big[ -G_{23} \sin(\cancel{\theta_2^{(0)} - \theta_3^{(0)}}) \\ &\qquad + B_{23} \cos(\cancel{\theta_2^{(0)} - \theta_3^{(0)}}) \Big] \\ &+ V_2 V_4^{(0)} \Big[ -G_{24} \sin(\cancel{\theta_2^{(0)} - \theta_4^{(0)}}) \\ &\qquad + B_{24} \cos(\cancel{\theta_2^{(0)} - \theta_4^{(0)}}) \Big] \end{aligned}
J11(0)=V2V1B21+V2V3(0)B23+V2V4(0)B24=1,05⋅1,05⋅10+1,05⋅1⋅10+1,05⋅1⋅10=32,025\begin{aligned} J_{11}^{(0)} &= V_2 V_1 B_{21} + V_2 V_3^{(0)} B_{23} \\ &\quad + V_2 V_4^{(0)} B_{24} \\ &= 1{,}05 \cdot 1{,}05 \cdot 10 + 1{,}05 \cdot 1 \cdot 10 \\ &\quad + 1{,}05 \cdot 1 \cdot 10 = 32{,}025 \end{aligned}
Qi=−Vi2Bii+Vi∑j∈αi[Vj(Gijsin⁡(θi−θj)−Bijcos⁡(θi−θj))]\begin{aligned} Q_i = -V_i^2 B_{ii} &+ V_i \sum_{j \in \alpha_i} \Big[ V_j \big( G_{ij} \sin(\theta_i - \theta_j) \\ &- B_{ij} \cos(\theta_i - \theta_j) \big) \Big] \end{aligned}
J44=∂(ΔQ3)∂V3=−2B33V3+∑j=1j≠34Vj[G3jsin⁡(θ3−θj)−B3jcos⁡(θ3−θj)]\begin{aligned} J_{44} &= \frac{\partial(\Delta Q_3)}{\partial V_3} \\ &= -2 B_{33} V_3 + \sum_{\substack{j = 1 \\ j \neq 3}}^{4} V_j \Big[ G_{3j} \sin(\theta_3 - \theta_j) \\ &\qquad - B_{3j} \cos(\theta_3 - \theta_j) \Big] \end{aligned}
J44(0)=−2B33V3(0)+V1[G31sin⁡(θ3(0)−θ10)−B31cos⁡(θ3(0)−θ1)]+V2[G32sin⁡(θ3(0)−θ2(0))−B32cos⁡(θ3(0)−θ2(0))]+V4(0)[G34sin⁡(θ3(0)−θ4(0))−B34cos⁡(θ3(0)−θ4(0))]\begin{aligned} J_{44}^{(0)} = {} &-2 B_{33} V_3^{(0)} \\ &+ V_1 \Big[ G_{31} \sin(\overset{0}{\cancel{\theta_3^{(0)} - \theta_1}}) \\ &\qquad - B_{31} \cos(\cancel{\theta_3^{(0)} - \theta_1}) \Big] \\ &+ V_2 \Big[ G_{32} \sin(\cancel{\theta_3^{(0)} - \theta_2^{(0)}}) \\ &\qquad - B_{32} \cos(\cancel{\theta_3^{(0)} - \theta_2^{(0)}}) \Big] \\ &+ V_4^{(0)} \Big[ G_{34} \sin(\cancel{\theta_3^{(0)} - \theta_4^{(0)}}) \\ &\qquad - B_{34} \cos(\cancel{\theta_3^{(0)} - \theta_4^{(0)}}) \Big] \end{aligned}
J44(0)=−2B33V3(0)−V1B31−V2B32−V4(0)B34=29\begin{aligned} J_{44}^{(0)} &= -2 B_{33} V_3^{(0)} - V_1 B_{31} \\ &\quad - V_2 B_{32} - V_4^{(0)} B_{34} \\ &= 29 \end{aligned}

Iterativni postupak proračuna:

1. Inicijalne vrednosti promenljivih stanja X(0)\boldsymbol{X}^{(0)}.

2. Vrši se popravka rešenja:

ΔX(k+1)=−[J(k)]−1F(X(k)),F(X(k))=Pi,Qi(X(k))−Pisp,Qisp\begin{gathered} \Delta \boldsymbol{X}^{(k+1)} = -\left[ \boldsymbol{J}^{(k)} \right]^{-1} \boldsymbol{F}\left( \boldsymbol{X}^{(k)} \right) , \\ \boldsymbol{F}\left( \boldsymbol{X}^{(k)} \right) = P_i, Q_i\left( \boldsymbol{X}^{(k)} \right) - P_i^{sp}, Q_i^{sp} \end{gathered}

3. koja koriguje rešenje:

X(k+1)=X(k)+ΔX(k+1),\boldsymbol{X}^{(k+1)} = \boldsymbol{X}^{(k)} + \Delta \boldsymbol{X}^{(k+1)} ,

4. posle čega se vrši provera kriterijuma konvergencije:

∣X(k+1)−X(k)∣≤ε.\left| \boldsymbol{X}^{(k+1)} - \boldsymbol{X}^{(k)} \right| \le \varepsilon .

Rezultat

Čvor 2 je PV čvor (P2=0,5P_2 = 0{,}5 r.j.), čvorovi 3 i 4 su PQ čvorovi; Jacobian matrica je petog reda.

U prvoj iteraciji iz ravnog profila: ∂(ΔP2)∂θ2=32,025\frac{\partial(\Delta P_2)}{\partial \theta_2} = 32{,}025 i ∂(ΔQ3)∂V3=29\frac{\partial(\Delta Q_3)}{\partial V_3} = 29.

Metod u predavanju

Slični zadaci

Teme

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