Grid and PV Fed Uninterruptible Induction Motor Drive Implementation and Measurements

Abstract

Motors powered directly from solar panels are becoming more and more popular in pump applications. However, solar panels can be the source of operational issues due to varying irradiance, ambient temperature, weather. This paper shows how it is worth expanding a solar induction motor drive to provide an uninterrupted flow of electricity to the motor. In addition, the main components of the uninterruptible induction motor drive are presented, including the LLC (inductor-inductor-capacitor) converter, the three-phase inverter, and the three-phase rectifier. LLC converters that can increase the voltage from 25–40 V to 330 V cannot be bought directly from manufacturers. Therefore, a custom LLC converter was made for the research. It was necessary to build a custom converter to avoid the use of solar panel strings. This way, solar panels connected in parallel can be used. A low-voltage (25–40 V) supply was implemented from the solar side, while the induction motor requires 230 V AC three-phase voltage in delta connection. For this reason, a voltage boost is required from the low voltage side. The grid feeds the universal DC link through the three-phase rectifier. This allows the motor to consume varying amounts of electricity from the grid or the solar panel. The study also presents in detail the LLC converter that performs the voltage boost. Measuring the entire motor drive, switching transients and efficiencies can be observed at different input voltages for different supplies as well as loads.

Napelemes szünetmentes aszinkron motorhajtás szigetüzemű inverterrel

“…Ha egy fázisra (230 V 50 Hz-es feszültség) is szükség van megszakítás nélkül, akkor érdemes több panel telepítését elvégezni, ilyenkor egyszerűen csatlakoztatható egy szigetüzemű inverter az akkumulátorokhoz és az egyenirányítóhoz. Ha az egyenirányító ki van kapcsolva, akkor olyan üzemállapot is elérhető, ahol az akkumulátort és a motort csak a napelemek táplálják (Boros-Bodnár, 2022).…”

“…A Továbbá az LLC konverter szabályozója azonnal beavatkozik ebben az esetben és átveszi a DC kör szabályzását (Boros-Bodnár, 2022).…”

“…Lehetőség van olyan üzemállapotra is, hogy a napelem és a hálózat egyszerre táplálja a fogyasztókat, amelynek aránya szintén beállítható (Boros-Bodnár, 2022). Ebben az esetben az egyenfeszültség átlagértéke a (2. képlet) szerint számítható.…”

Effect of SPWM Inverter in Combination with Solar Uninterruptible Induction Motor Drive

“…The equations for the calculations have been taken from the application notes of major electronics manufacturers [12,13]. The characteristics and design of the LLC converter can be found in our previous papers [14,15].…”

Applying a Sliding Mode Controller to Maximum Power Point Tracking in a Quasi Z-Source Inverter Based on the Power Curve of a Photovoltaic Cell

“…To implement the dc/dc converter, various converters are used, which can be referred to as a flyback, push-pull, and resonant converters with two inductors and one capacitor (LLC). Moreover, the second stage is a dc/ac inverter that injects an ac current proportional to the power produced by the PV module [4][5][6].…”