Konceptualni razvoj prenosnega testerja DC polnilnih postaj za električna vozila.

Pivk, Kristan (author), Jankovec, Marko (mentor)

V tem projektu smo izdelali delujoč koncept prenosnega testerja hitrih DC polnilnic za električna vozila (DC EVSE). Na podlagi začetnih testiranj s konceptom, ki je bil predstavljen v preteklosti, smo ocenili zahteve za simulator baterijskega paketa, ki se nahaja znotraj električnega avtomobila (EV). Ta simulator mora posnemati dejanski baterijski paket tako, da generira lastno napetost baterijskega paketa, ko EVSE ne izvaja polnjenja, in ohranja konstantno napetost na vhodnih sponkah, ko EVSE izvaja polnjenje. Ta simulator smo zasnovali z uporabo napetostnega vira, ki generira 290 V enosmerne napetosti na vhodnih sponkah ter linearnega paralelnega napetostnega regulatorja, ki vzdržuje 300 V napetosti med vhodnima sponkama v času polnjenja. Naš simulator smo dimenzionirali za simulacijo s 5 A nazivnega polnilnega toka. Poleg simulatorja baterijskega paketa smo za doseganje polnjenja preko CCS2 priključka izdelali komunikacijski krmilnik električnega vozila (EVCC). Izdelali smo ga z uporabo namenskega modula WHITE Beet PI 1.1 za digitalno komunikacijo med EVSE in EV ter ga krmilili z mikrokrmilnikom družine STM32U5. Za ta izdelek smo izdelali namenski uporabniški vmesnik za osebni računalnik z uporabo programskega orodja LabVIEW, ki nam je omogočal krmiljenje in spremljanje simulacije polnjenja. Ko smo potrdili delovanje koncepta, smo pričeli z izdelavo prenosnega testerja. V ta namen smo izdelali tudi namenski tiskani vezji. Na glavno tiskano vezje smo dodali voltmetre in ampermeter, s katerimi smo spremljali in beležili realne parametre polnjenja. Prav tako smo dodali vezje za simuliranje napak v izolaciji polnilnih vodnikov (DC+ in DC-) proti zaščitnemu vodniku (PE) in simulacije napak na komunikacijskih vodnikih CCS2 priključka. Te smo programsko podprli za izvajanje teh simulacij na terenu. Celoten tester smo postavili v kovček. S testerjem smo dosegali simulacijo polnjenja do 30 sekund. V tem času se je simulator baterijskega paketa zaradi odvajanja polnilne moči segrel za največ 10 °C glede na začetno temperaturo. S tem konceptom smo preizkusili velik del DC EVSE, ki so trenutno na voljo uporabnikom EV v Sloveniji. Rezultati testov so bili uspešni, saj smo pri vseh testiranih EVSE dosegli uspešno polnjenje. Trenutni produkt je namenjen zgolj uporabi v razvojne namene, a je podlaga za nadaljnji razvoj inštrumenta, ki bi ga lahko prodajali na trgu.

• Language: Slovenian
• Keywords: hitre DC EVSE, simulator baterijskega paketa, koncept prenosnega testerja, CCS2 priključek, EVCC, WHITE Beet PI 1.1, STM32U5
• Work type: Master's thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2024
• PID: 20.500.12556/RUL-160386
• ISBN: 207511043
• Publication date in RUL: 27.08.2024

Secondary language

• Language: English
• Title: Conceptual Development of a Portable Tester for DC Charging Stations for Electric Vehicles

Abstract

In this project, we created a working concept of a portable tester of fast DC chargers for electric vehicles (DC EVSE). Based on initial testing with a concept that was presented in the past, we assessed the requirements for a battery pack simulator, which simulates battery pack used inside an electric vehicle (EV). This simulator should mimic a real battery pack by generating the battery pack's own voltage when the EVSE is not charging and maintaining a constant voltage across the input terminals when the EVSE is charging. We implemented this simulator by using a voltage source that generates DC voltage of 290 V across the input terminals and a linear parallel voltage regulator that maintains a voltage of 300 V between the input terminals during charging. We designed our simulator to regulate voltage at a nominal charge current of 5 A. In addition to the battery pack simulator, we created an electric vehicle communication controller (EVCC) to achieve charging via the CCS2 connector. We built it using module WHITE Beet PI 1.1 which is dedicated for digital communication between EVSE and EV. We controlled it with an STM32U5 family microcontroller. We created a dedicated PC user interface for this product using the LabVIEWsoftware platform that allowed us to control and monitor the charging simulation. After we confirmed our concept was functional, we started developing the portable tester. For this purpose, we also developed custom printed circuit boards. We added voltmeters and an amperemeter to the main printed circuit board, which were used to monitor and record the real conditions of the charging. We also added a circuit to simulate charging conductor (DC+ and DC-) insulation faults relative to the protective conductor (PE) and to simulate faults on the communication conductors of the CCS2 connector. We provided firmware support to enable these simulations in the field. We placed the entire tester inside a case. We were able to simulate charging with this tester for up to 30 seconds. During this time, the battery pack simulator warmed up by a maximum of 10 °C compared to the initial temperature due to the dissipation of the charging power. With this concept, we tested a large portion of the DC EVSE that are currently available to EV users in Slovenia. The test results were successful, as we achieved successful charging on all tested EVSEs. The current product is intended for development purposes only, but it is the basis for further development of an instrument that could be sold on the market.

• Keywords: fast DC EVSE, battery pack simulator, concept of a portable tester, CCS2 connector, EVCC, WHITE Beet PI 1.1, STM32U5