Frequently Asked Questions

Question: What is the significance of the MPLOT option? 

Answer: As an alternative to ScopeView, Mplot is a Matlab-based plotting package which, depending on the user’s preference, can be used to plot EMTP-RV results. The results can be easily accessed in Matlab for post-processing. Mplot is the only plot package available to EMTP-RV users that can display statistical outputs of a statistical simulation.

Question: Is it possible to create a model for overvoltage protection calculation of the equipment in an electrical substation? Is EMTP-RV able to establish the proper arrangement of the surge arresters (number and place) in an outdoor or indoor electrical substation layout?

Answer: EMTP-RV can precisely model a variety of substation equipment including lightning arresters. It is the user's responsibility to place the arresters at convenient locations (e.g. at the power transformers) and evaluate the lightning overvoltages. This process may be repeated until an optimal design is achieved.

Question: Is it possible to calculate the natural frequency of power transformer?

Answer: The answer is positive if the user has obtained the various stray capacitances of the transformer. The first natural frequency, around 8-12 kHz, may be easily calculated by an equivalent circuit. The second and higher frequencies are usually difficult to obtain analytically.

Question: In what language are the Advanced models created? Can we write our own? What options do I have for specifying the prime mover driving, say, a synchronous generator?

Answer: Advanced models in EMTP-RV are created by various basic control components available in its libraries. EMTP-RV has DLL capabilities which allow you to write your own code and models just as if you were an EMTP-RV developer. Various prime mover models are available in the 'Controls of Machines' library. The user can create their own machine controller or easily modify an existing one.

Question: I want to check the u-i-characteristic of my surge arrester model, created in EMTP-RV. How can I display an u-i-characteristic in ScopeView?

Answer: Once the arrester is modeled, you can apply to it a ramped voltage source in the interval of interest and measure the arrester current. You can then plot, in ScopeView or Mplot, the V vs. I characteristic.

Question: Do you have any users in the aerospace field?

Answer: We currently have customers in military applications who switched to EMTP-RV for its unparalleled capability in machine modeling.