Running: ./testmodel.py --libraries=/home/hudson/saved_omc/libraries/.openmodelica/libraries/ --ompython_omhome=/usr PowerSystems_latest_PowerSystems.Examples.AC3ph.Transformation.TapChanger.conf.json
loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 3.2.3+maint.om/package.mo", uses=false)
loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 3.2.3+maint.om/package.mo", uses=false)
loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 3.2.3+maint.om/package.mo", uses=false)
loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/PowerSystems 1.0.1-master/package.mo", uses=false)
Using package PowerSystems with version 1.0.1 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/PowerSystems 1.0.1-master/package.mo)
Using package ModelicaServices with version 3.2.3 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 3.2.3+maint.om/package.mo)
Using package Modelica with version 3.2.3 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 3.2.3+maint.om/package.mo)
Using package Complex with version 3.2.3 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 3.2.3+maint.om/package.mo)
Running command: translateModel(PowerSystems.Examples.AC3ph.Transformation.TapChanger,tolerance=1e-06,outputFormat="mat",numberOfIntervals=5000,variableFilter="Time|meter1.alpha_v|meter1.p.1.|meter1.p.2.|meter1.p.3.|meter1.v_norm|meter12.alpha_v|meter12.p.1.|meter12.p.2.|meter12.p.3.|meter12.v_norm|meter22.alpha_v|meter22.p.1.|meter22.p.2.|meter22.p.3.|meter22.v_norm",fileNamePrefix="PowerSystems_latest_PowerSystems.Examples.AC3ph.Transformation.TapChanger")
translateModel(PowerSystems.Examples.AC3ph.Transformation.TapChanger,tolerance=1e-06,outputFormat="mat",numberOfIntervals=5000,variableFilter="Time|meter1.alpha_v|meter1.p.1.|meter1.p.2.|meter1.p.3.|meter1.v_norm|meter12.alpha_v|meter12.p.1.|meter12.p.2.|meter12.p.3.|meter12.v_norm|meter22.alpha_v|meter22.p.1.|meter22.p.2.|meter22.p.3.|meter22.v_norm",fileNamePrefix="PowerSystems_latest_PowerSystems.Examples.AC3ph.Transformation.TapChanger")
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 3.2.3+maint.om/package.mo): time 0.001804/0.001804, allocations: 186.5 kB / 17.27 MB, free: 4.504 MB / 13.93 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 3.2.3+maint.om/package.mo): time 1.676/1.676, allocations: 205.1 MB / 223.1 MB, free: 8.465 MB / 186.7 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 3.2.3+maint.om/package.mo): time 0.0009997/0.0009996, allocations: 100 kB / 270.5 MB, free: 8.434 MB / 218.7 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/PowerSystems 1.0.1-master/package.mo): time 0.1725/0.1725, allocations: 38.01 MB / 355.8 MB, free: 2.93 MB / 298.7 MB
Notification: Performance of FrontEnd - loaded program: time 0.001418/0.001418, allocations: 55.91 kB / 421.9 MB, free: 37.77 MB / 298.7 MB
Notification: Performance of FrontEnd - Absyn->SCode: time 0.2966/0.298, allocations: 55.24 MB / 477.1 MB, free: 9.91 MB / 314.7 MB
Notification: Performance of NFInst.instantiate(PowerSystems.Examples.AC3ph.Transformation.TapChanger): time 0.01092/0.309, allocations: 10.71 MB / 487.8 MB, free: 2.262 MB / 314.7 MB
Notification: Performance of NFInst.instExpressions: time 0.00732/0.3163, allocations: 3.981 MB / 491.8 MB, free: 15.46 MB / 330.7 MB
Notification: Performance of NFInst.updateImplicitVariability: time 0.002049/0.3184, allocations: 74.47 kB / 491.9 MB, free: 15.43 MB / 330.7 MB
Notification: Performance of NFTyping.typeComponents: time 0.003035/0.3215, allocations: 0.9852 MB / 492.8 MB, free: 14.86 MB / 330.7 MB
Notification: Performance of NFTyping.typeBindings: time 0.003465/0.3249, allocations: 1.053 MB / 493.9 MB, free: 14.32 MB / 330.7 MB
Notification: Performance of NFTyping.typeClassSections: time 0.002543/0.3275, allocations: 0.6213 MB / 494.5 MB, free: 14.03 MB / 330.7 MB
Notification: Performance of NFFlatten.flatten: time 0.006472/0.334, allocations: 4.148 MB / 498.7 MB, free: 12.64 MB / 330.7 MB
Notification: Performance of NFFlatten.resolveConnections: time 0.001642/0.3357, allocations: 0.7894 MB / 499.5 MB, free: 12.21 MB / 330.7 MB
Notification: Performance of NFEvalConstants.evaluate: time 0.002564/0.3382, allocations: 0.8484 MB / 0.4886 GB, free: 11.77 MB / 330.7 MB
Notification: Performance of NFSimplifyModel.simplify: time 0.003276/0.3415, allocations: 1.434 MB / 0.49 GB, free: 11.01 MB / 330.7 MB
Notification: Performance of NFPackage.collectConstants: time 0.0006468/0.3422, allocations: 81.31 kB / 0.4901 GB, free: 11.01 MB / 330.7 MB
Notification: Performance of NFFlatten.collectFunctions: time 0.002358/0.3446, allocations: 0.5744 MB / 0.4906 GB, free: 10.73 MB / 330.7 MB
Notification: Performance of NFScalarize.scalarize: time 0.002117/0.3467, allocations: 0.8884 MB / 0.4915 GB, free: 10.2 MB / 330.7 MB
Notification: Performance of NFVerifyModel.verify: time 0.002924/0.3497, allocations: 0.8439 MB / 0.4923 GB, free: 9.66 MB / 330.7 MB
Notification: Performance of NFConvertDAE.convert: time 0.003653/0.3533, allocations: 2.26 MB / 0.4945 GB, free: 8.172 MB / 330.7 MB
Notification: Performance of FrontEnd - DAE generated: time 5.771e-06/0.3534, allocations: 5.375 kB / 0.4945 GB, free: 8.168 MB / 330.7 MB
Notification: Performance of FrontEnd: time 1.343e-06/0.3534, allocations: 0 / 0.4945 GB, free: 8.168 MB / 330.7 MB
Notification: Performance of Transformations before backend: time 3.813e-05/0.3534, allocations: 0 / 0.4945 GB, free: 8.168 MB / 330.7 MB
Notification: Model statistics after passing the front-end and creating the data structures used by the back-end:
 * Number of equations: 423
 * Number of variables: 423
Notification: Performance of Generate backend data structure: time 0.004022/0.3574, allocations: 2.022 MB / 0.4965 GB, free: 6.672 MB / 330.7 MB
Notification: Performance of prepare preOptimizeDAE: time 4.644e-05/0.3575, allocations: 9.438 kB / 0.4965 GB, free: 6.672 MB / 330.7 MB
Notification: Performance of preOpt normalInlineFunction (simulation): time 0.002004/0.3595, allocations: 346.1 kB / 0.4968 GB, free: 6.508 MB / 330.7 MB
Notification: Performance of preOpt evaluateParameters (simulation): time 0.002262/0.3618, allocations: 1.026 MB / 0.4978 GB, free: 5.766 MB / 330.7 MB
Notification: Performance of preOpt simplifyIfEquations (simulation): time 9.588e-05/0.3619, allocations: 103.5 kB / 0.4979 GB, free: 5.719 MB / 330.7 MB
Notification: Performance of preOpt expandDerOperator (simulation): time 0.0003499/0.3623, allocations: 175.1 kB / 0.4981 GB, free: 5.648 MB / 330.7 MB
Notification: Performance of preOpt clockPartitioning (simulation): time 0.003517/0.3658, allocations: 2.339 MB / 0.5004 GB, free: 3.34 MB / 330.7 MB
Notification: Performance of preOpt findStateOrder (simulation): time 4.255e-05/0.3658, allocations: 7.938 kB / 0.5004 GB, free: 3.332 MB / 330.7 MB
Notification: Performance of preOpt replaceEdgeChange (simulation): time 0.0001309/0.366, allocations: 59.98 kB / 0.5005 GB, free: 3.273 MB / 330.7 MB
Notification: Performance of preOpt inlineArrayEqn (simulation): time 0.000507/0.3665, allocations: 218.8 kB / 0.5007 GB, free: 3.059 MB / 330.7 MB
Notification: Performance of preOpt removeEqualRHS (simulation): time 0.002851/0.3694, allocations: 1.85 MB / 0.5025 GB, free: 1.203 MB / 330.7 MB
Warning: The model contains alias variables with redundant start and/or conflicting nominal values. It is recommended to resolve the conflicts, because otherwise the system could be hard to solve. To print the conflicting alias sets and the chosen candidates please use -d=aliasConflicts.
Notification: Performance of preOpt removeSimpleEquations (simulation): time 0.01197/0.3813, allocations: 9.571 MB / 0.5118 GB, free: 7.121 MB / 346.7 MB
Notification: Performance of preOpt comSubExp (simulation): time 0.002221/0.3836, allocations: 1.54 MB / 0.5133 GB, free: 5.531 MB / 346.7 MB
Notification: Performance of preOpt resolveLoops (simulation): time 0.0008082/0.3844, allocations: 0.6175 MB / 0.5139 GB, free: 4.91 MB / 346.7 MB
Notification: Performance of preOpt evalFunc (simulation): time 7.635e-05/0.3845, allocations: 16.98 kB / 0.5139 GB, free: 4.891 MB / 346.7 MB
Notification: Performance of preOpt encapsulateWhenConditions (simulation): time 0.001082/0.3856, allocations: 0.8568 MB / 0.5148 GB, free: 3.988 MB / 346.7 MB
Notification: Performance of pre-optimization done (n=130): time 3.036e-06/0.3856, allocations: 0 / 0.5148 GB, free: 3.988 MB / 346.7 MB
Notification: Performance of matching and sorting (n=131): time 0.006141/0.3917, allocations: 4.015 MB / 0.5187 GB, free: 15.88 MB / 362.7 MB
Notification: Performance of inlineWhenForInitialization (initialization): time 0.000151/0.3919, allocations: 286.3 kB / 0.519 GB, free: 15.54 MB / 362.7 MB
Notification: Performance of selectInitializationVariablesDAE (initialization): time 0.001139/0.3931, allocations: 0.9146 MB / 0.5199 GB, free: 14.6 MB / 362.7 MB
Notification: Performance of collectPreVariables (initialization): time 6.621e-05/0.3931, allocations: 53.95 kB / 0.5199 GB, free: 14.54 MB / 362.7 MB
Notification: Performance of collectInitialEqns (initialization): time 0.0006105/0.3938, allocations: 0.7627 MB / 0.5207 GB, free: 13.77 MB / 362.7 MB
Notification: Performance of collectInitialBindings (initialization): time 0.0003482/0.3941, allocations: 457.6 kB / 0.5211 GB, free: 13.31 MB / 362.7 MB
Notification: Performance of simplifyInitialFunctions (initialization): time 0.0004406/0.3946, allocations: 331.2 kB / 0.5214 GB, free: 12.98 MB / 362.7 MB
Notification: Performance of setup shared object (initialization): time 0.0001375/0.3947, allocations: 353.9 kB / 0.5217 GB, free: 12.63 MB / 362.7 MB
Notification: Performance of preBalanceInitialSystem (initialization): time 0.0008488/0.3956, allocations: 0.5778 MB / 0.5223 GB, free: 12.05 MB / 362.7 MB
Notification: Performance of partitionIndependentBlocks (initialization): time 0.001233/0.3968, allocations: 1.178 MB / 0.5235 GB, free: 10.61 MB / 362.7 MB
Notification: Performance of analyzeInitialSystem (initialization): time 0.002387/0.3992, allocations: 1.993 MB / 0.5254 GB, free: 8.328 MB / 362.7 MB
Notification: Performance of solveInitialSystemEqSystem (initialization): time 1.082e-05/0.3992, allocations: 4 kB / 0.5254 GB, free: 8.324 MB / 362.7 MB
Notification: Performance of matching and sorting (n=227) (initialization): time 0.004368/0.4036, allocations: 2.497 MB / 0.5279 GB, free: 5.793 MB / 362.7 MB
Notification: Performance of prepare postOptimizeDAE: time 7.655e-05/0.4037, allocations: 71.39 kB / 0.5279 GB, free: 5.711 MB / 362.7 MB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 0.002701/0.4064, allocations: 1.565 MB / 0.5294 GB, free: 4.133 MB / 362.7 MB
Notification: Performance of postOpt tearingSystem (initialization): time 0.001605/0.408, allocations: 0.5458 MB / 0.53 GB, free: 3.578 MB / 362.7 MB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.001005/0.409, allocations: 331.5 kB / 0.5303 GB, free: 3.254 MB / 362.7 MB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 0.009221/0.4183, allocations: 8.708 MB / 0.5388 GB, free: 10.02 MB / 378.7 MB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.001281/0.4196, allocations: 75.95 kB / 0.5389 GB, free: 9.949 MB / 378.7 MB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 0.0001867/0.4198, allocations: 100 kB / 0.539 GB, free: 9.852 MB / 378.7 MB
Notification: Model statistics after passing the back-end for initialization:
 * Number of independent subsystems: 86
 * Number of states: 0 ()
 * Number of discrete variables: 21 (system.initime,tapRelay1.cnt_2,$PRE.tapRelay1.cnt_2,tapRelay1.cnt_1,$PRE.tapRelay1.cnt_1,$whenCondition4,$whenCondition3,tapRelay2.cnt_2,$PRE.tapRelay2.cnt_2,tapRelay2.cnt_1,$PRE.tapRelay2.cnt_1,$whenCondition2,$whenCondition1,tapRelay1.tap_2,$PRE.tapRelay1.tap_2,tapRelay1.tap_1,$PRE.tapRelay1.tap_1,tapRelay2.tap_2,$PRE.tapRelay2.tap_2,tapRelay2.tap_1,$PRE.tapRelay2.tap_1)
 * Number of discrete states: 0 ()
 * Number of clocked states: 0 ()
 * Top-level inputs: 0
Notification: Strong component statistics for initialization (175):
 * Single equations (assignments): 169
 * Array equations: 0
 * Algorithm blocks: 2
 * Record equations: 0
 * When equations: 0
 * If-equations: 0
 * Equation systems (not torn): 0
 * Torn equation systems: 4
 * Mixed (continuous/discrete) equation systems: 0
Notification: Torn system details for strict tearing set:
 * Linear torn systems (#iteration vars, #inner vars, density): 4 systems
   {(2,12,100.0%), (2,11,100.0%), (2,12,100.0%), (2,11,100.0%)}
 * Non-linear torn systems (#iteration vars, #inner vars): 0 systems
Notification: Performance of prepare postOptimizeDAE: time 0.00109/0.4209, allocations: 0.5958 MB / 0.5396 GB, free: 9.234 MB / 378.7 MB
Notification: Performance of postOpt lateInlineFunction (simulation): time 0.000271/0.4212, allocations: 126.5 kB / 0.5397 GB, free: 9.109 MB / 378.7 MB
Notification: Performance of postOpt wrapFunctionCalls (simulation): time 0.002472/0.4236, allocations: 1.539 MB / 0.5412 GB, free: 7.547 MB / 378.7 MB
Notification: Performance of postOpt inlineArrayEqn (simulation): time 1.103e-05/0.4237, allocations: 12 kB / 0.5412 GB, free: 7.535 MB / 378.7 MB
Notification: Performance of postOpt constantLinearSystem (simulation): time 7.574e-06/0.4237, allocations: 11.88 kB / 0.5412 GB, free: 7.523 MB / 378.7 MB
Notification: Performance of postOpt simplifysemiLinear (simulation): time 1.182e-05/0.4237, allocations: 7.969 kB / 0.5412 GB, free: 7.516 MB / 378.7 MB
Notification: Performance of postOpt removeSimpleEquations (simulation): time 0.005095/0.4288, allocations: 3.068 MB / 0.5442 GB, free: 4.355 MB / 378.7 MB
Notification: Performance of postOpt simplifyComplexFunction (simulation): time 6.422e-06/0.4288, allocations: 0 / 0.5442 GB, free: 4.355 MB / 378.7 MB
Notification: Performance of postOpt solveSimpleEquations (simulation): time 0.001312/0.4301, allocations: 299.8 kB / 0.5445 GB, free: 4.062 MB / 378.7 MB
Notification: Performance of postOpt tearingSystem (simulation): time 1.93e-05/0.4302, allocations: 8 kB / 0.5445 GB, free: 4.055 MB / 378.7 MB
Notification: Performance of postOpt inputDerivativesUsed (simulation): time 9.829e-05/0.4303, allocations: 35.98 kB / 0.5445 GB, free: 4.02 MB / 378.7 MB
Notification: Performance of postOpt calculateStrongComponentJacobians (simulation): time 1.094e-05/0.4303, allocations: 11.94 kB / 0.5445 GB, free: 4.008 MB / 378.7 MB
Notification: Performance of postOpt calculateStateSetsJacobians (simulation): time 1.854e-06/0.4303, allocations: 0 / 0.5445 GB, free: 4.008 MB / 378.7 MB
Notification: Performance of postOpt symbolicJacobian (simulation): time 0.01519/0.4455, allocations: 9.253 MB / 0.5536 GB, free: 10.55 MB / 394.7 MB
Notification: Performance of postOpt removeConstants (simulation): time 0.000729/0.4463, allocations: 295.4 kB / 0.5539 GB, free: 10.24 MB / 394.7 MB
Notification: Performance of postOpt simplifyTimeIndepFuncCalls (simulation): time 0.0002564/0.4465, allocations: 35.92 kB / 0.5539 GB, free: 10.21 MB / 394.7 MB
Notification: Performance of postOpt simplifyAllExpressions (simulation): time 0.0006641/0.4472, allocations: 44.09 kB / 0.5539 GB, free: 10.16 MB / 394.7 MB
Notification: Performance of postOpt findZeroCrossings (simulation): time 0.0001955/0.4474, allocations: 84.77 kB / 0.554 GB, free: 10.08 MB / 394.7 MB
Notification: Performance of postOpt collapseArrayExpressions (simulation): time 0.0001463/0.4476, allocations: 83.91 kB / 0.5541 GB, free: 10 MB / 394.7 MB
Notification: Performance of sorting global known variables: time 0.0009163/0.4485, allocations: 0.6025 MB / 0.5547 GB, free: 9.387 MB / 394.7 MB
Notification: Performance of sort global known variables: time 3.2e-07/0.4485, allocations: 0 / 0.5547 GB, free: 9.387 MB / 394.7 MB
Notification: Performance of remove unused functions: time 0.002198/0.4507, allocations: 0.5469 MB / 0.5552 GB, free: 8.84 MB / 394.7 MB
Notification: Model statistics after passing the back-end for simulation:
 * Number of independent subsystems: 8
 * Number of states: 6 (trafo1.i1[1],trafo1.i1[2],trafo1.i1[3],trafo2.i1[1],trafo2.i1[2],trafo2.i1[3])
 * Number of discrete variables: 13 ($whenCondition1,$whenCondition2,$whenCondition3,$whenCondition4,tapRelay2.tap_1,tapRelay2.tap_2,tapRelay2.cnt_1,tapRelay2.cnt_2,tapRelay1.tap_1,tapRelay1.tap_2,tapRelay1.cnt_1,tapRelay1.cnt_2,system.initime)
 * Number of discrete states: 12 (tapRelay1.tap_2,tapRelay1.cnt_2,$whenCondition4,tapRelay1.tap_1,tapRelay1.cnt_1,$whenCondition3,tapRelay2.tap_2,tapRelay2.cnt_2,$whenCondition2,tapRelay2.tap_1,tapRelay2.cnt_1,$whenCondition1)
 * Number of clocked states: 0 ()
 * Top-level inputs: 0
Notification: Strong component statistics for simulation (121):
 * Single equations (assignments): 118
 * Array equations: 0
 * Algorithm blocks: 2
 * Record equations: 0
 * When equations: 1
 * If-equations: 0
 * Equation systems (not torn): 0
 * Torn equation systems: 0
 * Mixed (continuous/discrete) equation systems: 0
Notification: Performance of Backend phase and start with SimCode phase: time 0.0002819/0.451, allocations: 143.1 kB / 0.5554 GB, free: 8.691 MB / 394.7 MB
Notification: Performance of simCode: created initialization part: time 0.00407/0.4551, allocations: 2.326 MB / 0.5576 GB, free: 6.289 MB / 394.7 MB
Notification: Performance of simCode: created event and clocks part: time 5.089e-06/0.4551, allocations: 0 / 0.5576 GB, free: 6.289 MB / 394.7 MB
Notification: Performance of simCode: created simulation system equations: time 0.001121/0.4562, allocations: 0.8767 MB / 0.5585 GB, free: 5.387 MB / 394.7 MB
Notification: Performance of simCode: created of all other equations (e.g. parameter, nominal, assert, etc): time 0.001246/0.4575, allocations: 216.2 kB / 0.5587 GB, free: 5.176 MB / 394.7 MB
Notification: Performance of simCode: created linear, non-linear and system jacobian parts: time 0.008567/0.4661, allocations: 4.906 MB / 0.5635 GB, free: 184 kB / 394.7 MB
Notification: Performance of simCode: some other stuff during SimCode phase: time 0.001996/0.4681, allocations: 1.501 MB / 0.5649 GB, free: 14.65 MB / 410.7 MB
Notification: Performance of simCode: alias equations: time 0.001656/0.4698, allocations: 494.3 kB / 0.5654 GB, free: 14.16 MB / 410.7 MB
Notification: Performance of simCode: all other stuff during SimCode phase: time 0.0004379/0.4702, allocations: 95.42 kB / 0.5655 GB, free: 14.07 MB / 410.7 MB
Notification: Performance of SimCode: time 1.623e-06/0.4703, allocations: 0 / 0.5655 GB, free: 14.07 MB / 410.7 MB
Notification: Performance of Templates: time 0.03238/0.5026, allocations: 18.25 MB / 0.5833 GB, free: 11.82 MB / 426.7 MB
make -j1 -f PowerSystems_latest_PowerSystems.Examples.AC3ph.Transformation.TapChanger.makefile
(rm -f PowerSystems_latest_PowerSystems.Examples.AC3ph.Transformation.TapChanger.pipe ; mkfifo PowerSystems_latest_PowerSystems.Examples.AC3ph.Transformation.TapChanger.pipe ; head -c 1048576 < PowerSystems_latest_PowerSystems.Examples.AC3ph.Transformation.TapChanger.pipe >> ../files/PowerSystems_latest_PowerSystems.Examples.AC3ph.Transformation.TapChanger.sim & ./PowerSystems_latest_PowerSystems.Examples.AC3ph.Transformation.TapChanger  -abortSlowSimulation -alarm=480  -emit_protected -lv LOG_STATS > PowerSystems_latest_PowerSystems.Examples.AC3ph.Transformation.TapChanger.pipe 2>&1)
diffSimulationResults("PowerSystems_latest_PowerSystems.Examples.AC3ph.Transformation.TapChanger_res.mat","/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork@2/OpenModelicaLibraryTesting/ReferenceFiles/PowerSystems/PowerSystems.Examples.AC3ph.Transformation.TapChanger.mat","../files/PowerSystems_latest_PowerSystems.Examples.AC3ph.Transformation.TapChanger.diff",relTol=0.003,relTolDiffMinMax=0.003,rangeDelta=0.001)
Reference file matches