<input id="testId" ng-model-options="{updateOn: 'blur'}"
       class="form-control ng-scope ng-valid-maxlength ng-valid-gcms-text
              ng-touched ng-dirty ng-valid-parse ng-invalid ng-invalid-required"
              name="testName" type="text" ng-model="testName"
              maxlength="100" required="" aria-required="true"
              aria-invalid="true"
              aria-describedby="question-error-description-testId">

document.getElementById("testid").value = "some value"
$("#testId").trigger("input");

<div ng-app="myApp" ng-controller="myCtrl">

<input id="testId" ng-value="myVar" ng-model-options="{updateOn: 'blur'}"
       class="form-control ng-scope ng-valid-maxlength ng-valid-gcms-text
              ng-touched ng-dirty ng-valid-parse ng-invalid ng-invalid-required"
              name="testName" type="text" ng-model="testName"
              maxlength="100" required="" aria-required="true"
              aria-invalid="true"
              aria-describedby="question-error-description-testId">

</div>
<script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
    $scope.myVar = "some value";
});
</script>