You didn't say how you create the new VM, from scratch or as a clone ?
Anyway, afaik there is currently no cmdlet switch to let you specify that a cloned VM shall be powered on after creation.
When you use the underlying API (CloneVM_Task) you have a property (poweron) in the VirtualMachineCloneSpec object, that lets you specify this.
In summary, not with any of the current cmdlets.
With the API Method you can define an automatic poweron with the clone method.