PSERC Project Power System State Estimation and Optimal by alicejenny

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									         PSERC Project
    Power System State Estimation
and Optimal Measurement Placement for
   Distributed Multi-Utility Operation

 A. Abur and G.M. Huang (PIs) J. Lei and B. Xu
                  (Students)

            Texas A&M University
   Outline
 Objectives
 Technical Approach
 Implementation
 Results
 Conclusions
            Objectives

 Optimal  Meter Placement
 FACTS Device Monitoring
 Distributed State Estimation
   Technical Approach
 Three   step meter placement
  – Choice of the minimum set
  – Choice of candidates
  – Optimal selection from candidates
 FACTS    device monitoring
  – Modeling with constraints
  – Incorporation into SE
Meter Placement Problem
   Choice of Essential Measurements Set.
    – If the system is observable: Factorize H matrix
    – Else: Run LAV estimator


   Candidate Identification
    – Form Contingency–Measurement incidence matrix


   Optimal Candidate selection
    – Use of integer programming
        Contingencies
Types of Contingencies:
   Line Outage
   Measurement Loss
   Bus Split

Robustness Options:
   Against user defined contingency list
   Bad data Detectability
   All single line outages
Graphic User Interface




  Add injections at bus 3 and 4
FACTS Device Monitoring
UPFC Modeling:
   Two V-source model
   Four parameters
   Constraints

Integration into the SE:
   Use Hachtel’s formulation
   Inequality and equality constraints
                Model of UPFC
 Physical Model of UPFC
                      Model of UPFC
 Steady State Model of UPFC
                                       VB  B
             Pkm  jQkm                             ZB       Pmk  jQmk
             Pkm  jQkm                             ZB
  k                                                                       m
                              IE
                 ZE                                  IB
                              IB
                                                     IB
                              PB  PE  0
          V E  E




The constraint PB + PE = 0 implies that no real-power is exchanged between
the UPFC and the system.
                            Measurements
 Real and reactive power through k-m

         Vk Vm                 Vk V E                   Vk V B
 Pkm             sin  km             sin  k , E                 sin  k , B   (1)
          XB                    XE                         XB
       XE  XE      Vk Vm            Vk V E               Vk V B
Q km          Vk        cos  km         cos  k , E         cos  k , B
                 2
                                                                                   (2)
        XBXE         XB               XE                   XB
         Vk Vm                 Vm V B
 Pmk             sin  mk              sin  m , B                               (3)
          XB                     XB
              2
         Vm           Vk Vm               Vm V B
Qmk                         cos mk                  cos m , B                 (4)
          XB           XB                    XB
                        Constraints
 Equality and inequality constraints of UPFC

  Real Power Constraints:                P E P B  0             (5)

                                           PE  Q E  TE ,m ax
                                              2         2
  Shunt Power Constraints:                                        (6)

                                            PB  Q B  TB ,m ax
                                               2        2
  Series Power Constraints:                                       (7)

  Shunt Voltage Constraints:             V B  V B ,m ax          (8)

                                         V E  V E ,max
  Series Voltage Constraints:                                     (9)



  • VB, θB, VB and θB are the control parameters of UPFC
      Hachtel’s Method

          1 T 1
min         r R r
          2
s.t       f ( x)  s    0
            c( x)       0
         r  z  h( x )  0
              s         0
             Hachtel’s Method
 KKT first order optimality conditions :




  D         0       0      F       f (xk ) 
  0         0       0          
                            G      g(x )  k 
                                   
  0        0       R       H      z  h( x k ) 
   T                                            
  F       G T
                   H T
                            0  x      0        
                                                     
     Example
 FACTS device
   (UPFC) is installed
   on line 6-12, near
   bus 6




Parameters of the installed UPFC device

 From (bus)   To (bus)   XB    XE    VB,max   VE,max   SB,max   SE,max
     6          12       0.7   0.7    1.0      1.0      1.0      1.0
                        Estimation Results
  Function of the program as an estimator
    Voltages and powers of UPFC

        VB         θB         PB      SB       VE         θE        PE         SE
      0.1099     60.07     0.0014   0.0128   1.0679     -14.31   -0.0014    0.0035

  • Note that PB + PE = 0 and VB < 1.0, VE < 1.0, SB < 1.0, SE < 1.0, which correctly
    satisfy all the constraints.

 Function of the program as a power flow controller
    Set power flow in line 6-12 to be 0.1 + j0.1
    Voltages and powers of UPFC

       VB         θB         PB      SB        VE         θE         PE        SE
     0.1236     9.0530     0.0056   0.0159   1.0000   -14.6037    -0.0056    0.0691
           Conclusions

Optimal meter placement accounting for
contingencies and loss of measurements
State estimation of systems with FACTS devices
and their parameters
Setting of parameters of FACTS devices for
desired power flows

								
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