Sample code to run powershell in c# and generate json of the objects returned

run ps.linq

<Query Kind="Program">
  <Reference>&lt;ProgramFilesX86&gt;\Reference Assemblies\Microsoft\WindowsPowerShell\3.0\System.Management.Automation.dll</Reference>
  <Namespace>Microsoft.VisualBasic</Namespace>
  <Namespace>System.Threading.Tasks</Namespace>
  <Namespace>System.Management.Automation.Runspaces</Namespace>
  <Namespace>System.Collections.ObjectModel</Namespace>
  <Namespace>System.Management.Automation</Namespace>
</Query>

void Main()
{
	RunScript("Get-Process").Dump();
}

// Define other methods and classes here
private string RunScript(string scriptText)
{
	// create Powershell runspace

	Runspace runspace = RunspaceFactory.CreateRunspace();

	// open it

	runspace.Open();
	Runspace.DefaultRunspace = runspace;
	// create a pipeline and feed it the script text

	Pipeline pipeline = runspace.CreatePipeline();
	pipeline.Commands.AddScript(scriptText);

	// add an extra command to transform the script
	// output objects into nicely formatted strings

	// remove this line to get the actual objects
	// that the script returns. For example, the script

	// "Get-Process" returns a collection
	// of System.Diagnostics.Process instances.

	pipeline.Commands.Add("ConvertTo-Json");

	// execute the script

	Collection<PSObject> results = pipeline.Invoke();
	//results.Dump();

	var finalResults = string.Join(Environment.NewLine, results);

	// close the runspace

	runspace.Close();
	Runspace.DefaultRunspace = null;


	// convert the script result into a single string

	return finalResults;
}