Actual source code: ex9adj.c

  1: static char help[] = "Basic equation for generator stability analysis.\n";

  3: /*F

  5: \begin{eqnarray}
  6:                  \frac{d \theta}{dt} = \omega_b (\omega - \omega_s)
  7:                  \frac{2 H}{\omega_s}\frac{d \omega}{dt} & = & P_m - P_max \sin(\theta) -D(\omega - \omega_s)\\
  8: \end{eqnarray}

 10:   Ensemble of initial conditions
 11:    ./ex9 -ensemble -ts_monitor_draw_solution_phase -1,-3,3,3 -ts_adapt_dt_max .01 -ts_monitor -ts_type rk -pc_type lu -ksp_type preonly

 13:   Fault at .1 seconds
 14:    ./ex9 -ts_monitor_draw_solution_phase .42,.95,.6,1.05 -ts_adapt_dt_max .01 -ts_monitor -ts_type rk -pc_type lu -ksp_type preonly

 16:   Initial conditions same as when fault is ended
 17:    ./ex9 -u 0.496792,1.00932 -ts_monitor_draw_solution_phase .42,.95,.6,1.05 -ts_adapt_dt_max .01 -ts_monitor -ts_type rk -pc_type lu -ksp_type preonly

 19: F*/

 21: /*
 22:    Include "petscts.h" so that we can use TS solvers.  Note that this
 23:    file automatically includes:
 24:      petscsys.h       - base PETSc routines   petscvec.h - vectors
 25:      petscmat.h - matrices
 26:      petscis.h     - index sets            petscksp.h - Krylov subspace methods
 27:      petscviewer.h - viewers               petscpc.h  - preconditioners
 28:      petscksp.h   - linear solvers
 29: */

 31: #include <petscts.h>

 33: typedef struct {
 34:   PetscScalar H, D, omega_b, omega_s, Pmax, Pm, E, V, X, u_s, c;
 35:   PetscInt    beta;
 36:   PetscReal   tf, tcl;
 37: } AppCtx;

 39: PetscErrorCode PostStepFunction(TS ts)
 40: {
 41:   Vec                U;
 42:   PetscReal          t;
 43:   const PetscScalar *u;

 45:   PetscFunctionBegin;
 46:   PetscCall(TSGetTime(ts, &t));
 47:   PetscCall(TSGetSolution(ts, &U));
 48:   PetscCall(VecGetArrayRead(U, &u));
 49:   PetscCall(PetscPrintf(PETSC_COMM_SELF, "delta(%3.2f) = %8.7f\n", (double)t, (double)u[0]));
 50:   PetscCall(VecRestoreArrayRead(U, &u));
 51:   PetscFunctionReturn(PETSC_SUCCESS);
 52: }

 54: /*
 55:      Defines the ODE passed to the ODE solver
 56: */
 57: static PetscErrorCode RHSFunction(TS ts, PetscReal t, Vec U, Vec F, AppCtx *ctx)
 58: {
 59:   PetscScalar       *f, Pmax;
 60:   const PetscScalar *u;

 62:   PetscFunctionBegin;
 63:   /*  The next three lines allow us to access the entries of the vectors directly */
 64:   PetscCall(VecGetArrayRead(U, &u));
 65:   PetscCall(VecGetArray(F, &f));
 66:   if ((t > ctx->tf) && (t < ctx->tcl)) Pmax = 0.0; /* A short-circuit on the generator terminal that drives the electrical power output (Pmax*sin(delta)) to 0 */
 67:   else Pmax = ctx->Pmax;

 69:   f[0] = ctx->omega_b * (u[1] - ctx->omega_s);
 70:   f[1] = (-Pmax * PetscSinScalar(u[0]) - ctx->D * (u[1] - ctx->omega_s) + ctx->Pm) * ctx->omega_s / (2.0 * ctx->H);

 72:   PetscCall(VecRestoreArrayRead(U, &u));
 73:   PetscCall(VecRestoreArray(F, &f));
 74:   PetscFunctionReturn(PETSC_SUCCESS);
 75: }

 77: /*
 78:      Defines the Jacobian of the ODE passed to the ODE solver. See TSSetIJacobian() for the meaning of a and the Jacobian.
 79: */
 80: static PetscErrorCode RHSJacobian(TS ts, PetscReal t, Vec U, Mat A, Mat B, AppCtx *ctx)
 81: {
 82:   PetscInt           rowcol[] = {0, 1};
 83:   PetscScalar        J[2][2], Pmax;
 84:   const PetscScalar *u;

 86:   PetscFunctionBegin;
 87:   PetscCall(VecGetArrayRead(U, &u));
 88:   if ((t > ctx->tf) && (t < ctx->tcl)) Pmax = 0.0; /* A short-circuit on the generator terminal that drives the electrical power output (Pmax*sin(delta)) to 0 */
 89:   else Pmax = ctx->Pmax;

 91:   J[0][0] = 0;
 92:   J[0][1] = ctx->omega_b;
 93:   J[1][1] = -ctx->D * ctx->omega_s / (2.0 * ctx->H);
 94:   J[1][0] = -Pmax * PetscCosScalar(u[0]) * ctx->omega_s / (2.0 * ctx->H);

 96:   PetscCall(MatSetValues(A, 2, rowcol, 2, rowcol, &J[0][0], INSERT_VALUES));
 97:   PetscCall(VecRestoreArrayRead(U, &u));

 99:   PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
100:   PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
101:   if (A != B) {
102:     PetscCall(MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY));
103:     PetscCall(MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY));
104:   }
105:   PetscFunctionReturn(PETSC_SUCCESS);
106: }

108: static PetscErrorCode RHSJacobianP(TS ts, PetscReal t, Vec X, Mat A, void *ctx0)
109: {
110:   PetscInt    row[] = {0, 1}, col[] = {0};
111:   PetscScalar J[2][1];
112:   AppCtx     *ctx = (AppCtx *)ctx0;

114:   PetscFunctionBeginUser;
115:   J[0][0] = 0;
116:   J[1][0] = ctx->omega_s / (2.0 * ctx->H);
117:   PetscCall(MatSetValues(A, 2, row, 1, col, &J[0][0], INSERT_VALUES));
118:   PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
119:   PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
120:   PetscFunctionReturn(PETSC_SUCCESS);
121: }

123: static PetscErrorCode CostIntegrand(TS ts, PetscReal t, Vec U, Vec R, AppCtx *ctx)
124: {
125:   PetscScalar       *r;
126:   const PetscScalar *u;

128:   PetscFunctionBegin;
129:   PetscCall(VecGetArrayRead(U, &u));
130:   PetscCall(VecGetArray(R, &r));
131:   r[0] = ctx->c * PetscPowScalarInt(PetscMax(0., u[0] - ctx->u_s), ctx->beta);
132:   PetscCall(VecRestoreArray(R, &r));
133:   PetscCall(VecRestoreArrayRead(U, &u));
134:   PetscFunctionReturn(PETSC_SUCCESS);
135: }

137: static PetscErrorCode DRDUJacobianTranspose(TS ts, PetscReal t, Vec U, Mat DRDU, Mat B, AppCtx *ctx)
138: {
139:   PetscScalar        ru[1];
140:   const PetscScalar *u;
141:   PetscInt           row[] = {0}, col[] = {0};

143:   PetscFunctionBegin;
144:   PetscCall(VecGetArrayRead(U, &u));
145:   ru[0] = ctx->c * ctx->beta * PetscPowScalarInt(PetscMax(0., u[0] - ctx->u_s), ctx->beta - 1);
146:   PetscCall(VecRestoreArrayRead(U, &u));
147:   PetscCall(MatSetValues(DRDU, 1, row, 1, col, ru, INSERT_VALUES));
148:   PetscCall(MatAssemblyBegin(DRDU, MAT_FINAL_ASSEMBLY));
149:   PetscCall(MatAssemblyEnd(DRDU, MAT_FINAL_ASSEMBLY));
150:   PetscFunctionReturn(PETSC_SUCCESS);
151: }

153: static PetscErrorCode DRDPJacobianTranspose(TS ts, PetscReal t, Vec U, Mat DRDP, AppCtx *ctx)
154: {
155:   PetscFunctionBegin;
156:   PetscCall(MatZeroEntries(DRDP));
157:   PetscCall(MatAssemblyBegin(DRDP, MAT_FINAL_ASSEMBLY));
158:   PetscCall(MatAssemblyEnd(DRDP, MAT_FINAL_ASSEMBLY));
159:   PetscFunctionReturn(PETSC_SUCCESS);
160: }

162: PetscErrorCode ComputeSensiP(Vec lambda, Vec mu, AppCtx *ctx)
163: {
164:   PetscScalar        sensip;
165:   const PetscScalar *x, *y;

167:   PetscFunctionBegin;
168:   PetscCall(VecGetArrayRead(lambda, &x));
169:   PetscCall(VecGetArrayRead(mu, &y));
170:   sensip = 1. / PetscSqrtScalar(1. - (ctx->Pm / ctx->Pmax) * (ctx->Pm / ctx->Pmax)) / ctx->Pmax * x[0] + y[0];
171:   PetscCall(PetscPrintf(PETSC_COMM_WORLD, "\n sensitivity wrt parameter pm: %.7f \n", (double)sensip));
172:   PetscCall(VecRestoreArrayRead(lambda, &x));
173:   PetscCall(VecRestoreArrayRead(mu, &y));
174:   PetscFunctionReturn(PETSC_SUCCESS);
175: }

177: int main(int argc, char **argv)
178: {
179:   TS           ts, quadts; /* ODE integrator */
180:   Vec          U;          /* solution will be stored here */
181:   Mat          A;          /* Jacobian matrix */
182:   Mat          Jacp;       /* Jacobian matrix */
183:   Mat          DRDU, DRDP;
184:   PetscMPIInt  size;
185:   PetscInt     n = 2;
186:   AppCtx       ctx;
187:   PetscScalar *u;
188:   PetscReal    du[2]    = {0.0, 0.0};
189:   PetscBool    ensemble = PETSC_FALSE, flg1, flg2;
190:   PetscReal    ftime;
191:   PetscInt     steps;
192:   PetscScalar *x_ptr, *y_ptr;
193:   Vec          lambda[1], q, mu[1];

195:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
196:      Initialize program
197:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
198:   PetscFunctionBeginUser;
199:   PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));
200:   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
201:   PetscCheck(size == 1, PETSC_COMM_WORLD, PETSC_ERR_WRONG_MPI_SIZE, "Only for sequential runs");

203:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
204:     Create necessary matrix and vectors
205:     - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
206:   PetscCall(MatCreate(PETSC_COMM_WORLD, &A));
207:   PetscCall(MatSetSizes(A, n, n, PETSC_DETERMINE, PETSC_DETERMINE));
208:   PetscCall(MatSetType(A, MATDENSE));
209:   PetscCall(MatSetFromOptions(A));
210:   PetscCall(MatSetUp(A));

212:   PetscCall(MatCreateVecs(A, &U, NULL));

214:   PetscCall(MatCreate(PETSC_COMM_WORLD, &Jacp));
215:   PetscCall(MatSetSizes(Jacp, PETSC_DECIDE, PETSC_DECIDE, 2, 1));
216:   PetscCall(MatSetFromOptions(Jacp));
217:   PetscCall(MatSetUp(Jacp));

219:   PetscCall(MatCreateDense(PETSC_COMM_WORLD, PETSC_DECIDE, PETSC_DECIDE, 1, 1, NULL, &DRDP));
220:   PetscCall(MatSetUp(DRDP));
221:   PetscCall(MatCreateDense(PETSC_COMM_WORLD, PETSC_DECIDE, PETSC_DECIDE, 1, 2, NULL, &DRDU));
222:   PetscCall(MatSetUp(DRDU));

224:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
225:     Set runtime options
226:     - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
227:   PetscOptionsBegin(PETSC_COMM_WORLD, NULL, "Swing equation options", "");
228:   {
229:     ctx.beta    = 2;
230:     ctx.c       = 10000.0;
231:     ctx.u_s     = 1.0;
232:     ctx.omega_s = 1.0;
233:     ctx.omega_b = 120.0 * PETSC_PI;
234:     ctx.H       = 5.0;
235:     PetscCall(PetscOptionsScalar("-Inertia", "", "", ctx.H, &ctx.H, NULL));
236:     ctx.D = 5.0;
237:     PetscCall(PetscOptionsScalar("-D", "", "", ctx.D, &ctx.D, NULL));
238:     ctx.E    = 1.1378;
239:     ctx.V    = 1.0;
240:     ctx.X    = 0.545;
241:     ctx.Pmax = ctx.E * ctx.V / ctx.X;
242:     PetscCall(PetscOptionsScalar("-Pmax", "", "", ctx.Pmax, &ctx.Pmax, NULL));
243:     ctx.Pm = 1.1;
244:     PetscCall(PetscOptionsScalar("-Pm", "", "", ctx.Pm, &ctx.Pm, NULL));
245:     ctx.tf  = 0.1;
246:     ctx.tcl = 0.2;
247:     PetscCall(PetscOptionsReal("-tf", "Time to start fault", "", ctx.tf, &ctx.tf, NULL));
248:     PetscCall(PetscOptionsReal("-tcl", "Time to end fault", "", ctx.tcl, &ctx.tcl, NULL));
249:     PetscCall(PetscOptionsBool("-ensemble", "Run ensemble of different initial conditions", "", ensemble, &ensemble, NULL));
250:     if (ensemble) {
251:       ctx.tf  = -1;
252:       ctx.tcl = -1;
253:     }

255:     PetscCall(VecGetArray(U, &u));
256:     u[0] = PetscAsinScalar(ctx.Pm / ctx.Pmax);
257:     u[1] = 1.0;
258:     PetscCall(PetscOptionsRealArray("-u", "Initial solution", "", u, &n, &flg1));
259:     n = 2;
260:     PetscCall(PetscOptionsRealArray("-du", "Perturbation in initial solution", "", du, &n, &flg2));
261:     u[0] += du[0];
262:     u[1] += du[1];
263:     PetscCall(VecRestoreArray(U, &u));
264:     if (flg1 || flg2) {
265:       ctx.tf  = -1;
266:       ctx.tcl = -1;
267:     }
268:   }
269:   PetscOptionsEnd();

271:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
272:      Create timestepping solver context
273:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
274:   PetscCall(TSCreate(PETSC_COMM_WORLD, &ts));
275:   PetscCall(TSSetProblemType(ts, TS_NONLINEAR));
276:   PetscCall(TSSetEquationType(ts, TS_EQ_ODE_EXPLICIT)); /* less Jacobian evaluations when adjoint BEuler is used, otherwise no effect */
277:   PetscCall(TSSetType(ts, TSRK));
278:   PetscCall(TSSetRHSFunction(ts, NULL, (TSRHSFunction)RHSFunction, &ctx));
279:   PetscCall(TSSetRHSJacobian(ts, A, A, (TSRHSJacobian)RHSJacobian, &ctx));
280:   PetscCall(TSCreateQuadratureTS(ts, PETSC_TRUE, &quadts));
281:   PetscCall(TSSetRHSFunction(quadts, NULL, (TSRHSFunction)CostIntegrand, &ctx));
282:   PetscCall(TSSetRHSJacobian(quadts, DRDU, DRDU, (TSRHSJacobian)DRDUJacobianTranspose, &ctx));
283:   PetscCall(TSSetRHSJacobianP(quadts, DRDP, (TSRHSJacobianP)DRDPJacobianTranspose, &ctx));
284:   PetscCall(TSSetCostGradients(ts, 1, lambda, mu));
285:   PetscCall(TSSetRHSJacobianP(ts, Jacp, RHSJacobianP, &ctx));

287:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
288:      Set initial conditions
289:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
290:   PetscCall(TSSetSolution(ts, U));

292:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
293:     Save trajectory of solution so that TSAdjointSolve() may be used
294:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
295:   PetscCall(TSSetSaveTrajectory(ts));

297:   PetscCall(MatCreateVecs(A, &lambda[0], NULL));
298:   /*   Set initial conditions for the adjoint integration */
299:   PetscCall(VecGetArray(lambda[0], &y_ptr));
300:   y_ptr[0] = 0.0;
301:   y_ptr[1] = 0.0;
302:   PetscCall(VecRestoreArray(lambda[0], &y_ptr));

304:   PetscCall(MatCreateVecs(Jacp, &mu[0], NULL));
305:   PetscCall(VecGetArray(mu[0], &x_ptr));
306:   x_ptr[0] = -1.0;
307:   PetscCall(VecRestoreArray(mu[0], &x_ptr));

309:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
310:      Set solver options
311:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
312:   PetscCall(TSSetMaxTime(ts, 10.0));
313:   PetscCall(TSSetExactFinalTime(ts, TS_EXACTFINALTIME_MATCHSTEP));
314:   PetscCall(TSSetTimeStep(ts, .01));
315:   PetscCall(TSSetFromOptions(ts));

317:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
318:      Solve nonlinear system
319:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
320:   if (ensemble) {
321:     for (du[1] = -2.5; du[1] <= .01; du[1] += .1) {
322:       PetscCall(VecGetArray(U, &u));
323:       u[0] = PetscAsinScalar(ctx.Pm / ctx.Pmax);
324:       u[1] = ctx.omega_s;
325:       u[0] += du[0];
326:       u[1] += du[1];
327:       PetscCall(VecRestoreArray(U, &u));
328:       PetscCall(TSSetTimeStep(ts, .01));
329:       PetscCall(TSSolve(ts, U));
330:     }
331:   } else {
332:     PetscCall(TSSolve(ts, U));
333:   }
334:   PetscCall(VecView(U, PETSC_VIEWER_STDOUT_WORLD));
335:   PetscCall(TSGetSolveTime(ts, &ftime));
336:   PetscCall(TSGetStepNumber(ts, &steps));

338:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
339:      Adjoint model starts here
340:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
341:   /*   Set initial conditions for the adjoint integration */
342:   PetscCall(VecGetArray(lambda[0], &y_ptr));
343:   y_ptr[0] = 0.0;
344:   y_ptr[1] = 0.0;
345:   PetscCall(VecRestoreArray(lambda[0], &y_ptr));

347:   PetscCall(VecGetArray(mu[0], &x_ptr));
348:   x_ptr[0] = -1.0;
349:   PetscCall(VecRestoreArray(mu[0], &x_ptr));

351:   PetscCall(TSAdjointSolve(ts));

353:   PetscCall(PetscPrintf(PETSC_COMM_WORLD, "\n sensitivity wrt initial conditions: d[Psi(tf)]/d[phi0]  d[Psi(tf)]/d[omega0]\n"));
354:   PetscCall(VecView(lambda[0], PETSC_VIEWER_STDOUT_WORLD));
355:   PetscCall(VecView(mu[0], PETSC_VIEWER_STDOUT_WORLD));
356:   PetscCall(TSGetCostIntegral(ts, &q));
357:   PetscCall(VecView(q, PETSC_VIEWER_STDOUT_WORLD));
358:   PetscCall(VecGetArray(q, &x_ptr));
359:   PetscCall(PetscPrintf(PETSC_COMM_WORLD, "\n cost function=%g\n", (double)(x_ptr[0] - ctx.Pm)));
360:   PetscCall(VecRestoreArray(q, &x_ptr));

362:   PetscCall(ComputeSensiP(lambda[0], mu[0], &ctx));

364:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
365:      Free work space.  All PETSc objects should be destroyed when they are no longer needed.
366:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
367:   PetscCall(MatDestroy(&A));
368:   PetscCall(MatDestroy(&Jacp));
369:   PetscCall(MatDestroy(&DRDU));
370:   PetscCall(MatDestroy(&DRDP));
371:   PetscCall(VecDestroy(&U));
372:   PetscCall(VecDestroy(&lambda[0]));
373:   PetscCall(VecDestroy(&mu[0]));
374:   PetscCall(TSDestroy(&ts));
375:   PetscCall(PetscFinalize());
376:   return 0;
377: }

379: /*TEST

381:    build:
382:       requires: !complex

384:    test:
385:       args: -viewer_binary_skip_info -ts_adapt_type none

387: TEST*/