PELS.IAS/UFRJ is a student team from the Federal University of Rio de Janeiro (UFRJ) focused on the design and manufacturing of power electronics projects. One of the top goals of the team is to promote projects associated with power electronics technologies that have an industrial application or are associated with sustainability and energy efficiency.
PELS.IAS/UFRJ consists of over 27 members spread across 3 technical subteams: Academic Activities, Marketing, and Projects.
The team is currently working on an Uninterruptible Power Supply (UPS) project (prototype expected for 2022) with which they are planning to compete in International competitions organized by IEEE and PELS.
Paolo Erazo is the chapter’s Project Manager (2021 – 2022) as well as serving the team as a technical advisor.
“I have been using PSIM since 2017 in power electronics design projects, specifically using the features of embedded code generation and simulations for Hardware-in-the-Loop experiments. I have utilized the tool to simulate control algorithms for distributed energy resources converters and uninterruptible power supply (UPS). PSIM is very user-friendly, optimizes the development time, and helps me to validate results quickly. It is a great tool for power electronics embedded control design.”
“Thanks to the PSIM’s sponsorship, our Project Subteam is able to work with the full software license which includes simulations with unlimited numbers of elements, plus all the additional libraries of renewable sources and microgrids.
We are developing the project of an Uninterruptible Power Supply (UPS). UPS’s, or also No-Breaks, are used to meet critical loads so that, in case there is a failure in the network to which a piece of equipment is connected, the energy supply will not be interrupted. The equipment has 3 power converters and a battery bank. The converter developed in this project consists of a single-phase inverter where the DC supply voltage comes from the battery bank.”
Paolo says, he and his teammates found PSIM particularly critical for several steps of the process:
Find Smart Battery Charger Controller Parameters:
The cascade voltage and current controller is designed with Smart Control for charging in constant current, and then through constant voltage mode.
Conditioning of voltage and current sensors:
Quickly adjust the sensor voltage or current sensor to the operating range of our controllers. This agility is also useful for us if we need to change the output value of the circuit from, for example, 5V to 3.3V, and to study the behavior of the circuit under other conditions.
Single Phase Phase-Locked-Loop:
In 2021, PELS.IAS/UFRJ had a Selection Process and, consequently, new members. We needed to create training resources for them and we had the idea to implement a Single Phase Phase-Locked-Loop. With this, we teach them how to implement the power part and the control part in the software and how to implement a real simple controller. It can be seen in Figure 1 .
Figure 1 – Single Phase Phase-Locked-Loop curves
Figure 2 – Load voltage and current curves
Validation of single-phase inverter dq control:
In Figure 2, you can see the voltage and current of the load after the LC filter output of the single-phase full-bridge inverter.
It can be seen in Figure 3 that the controls have fault ride-through capability, reject the disturbance, and equalize the reference (red) again. Thus, the system proves to be robust to disturbances of this magnitude.
Figure 3 – Voltage and current curves
During the pandemic restrictions, our team worked only with simulations. But in recent months we had made progress with our prototype and started to build an open-loop inverter, the converter that will supply the load in extreme cases.
The pictures below show the base version of the proposed prototype and the open-loop operation of the Battery bank and the Inverter:
Open-loop prototype showing PWM signal from the converter and HMI (left) and Open-loop prototype during loading (right)
With PSIM we test and validate the power and control part of the inverter. To find the controller gain values, we use the SmartCtrl program. Which allows us to find the values in a faster and more didactic way.”
If you want to learn more about the team and stay informed about what they are up to you can follow them on Instagram @pelsias.ufrj or check out their chapter website.