PID-Based Electronic Load Control Card Design for Self-Excited Induction Generators Driven by Pump-as-Turbine Systems
Abstract
This paper presents the design, simulation, and experimental validation of a low-cost PID based electronic load control (ELC) card for a self-excited induction generator (SEIG) driven by a pump-as-turbine (PAT) system operating in off-grid conditions. The primary challenge addressed is the regulation of terminal voltage and output frequency under varying single-phase resistive loads connected to a three-phase SEIG via the C-2C (Steinmetz) capacitor configuration. A ballast load driver circuit employing an IGBT switched at 500 Hz by PWM is governed by a PID algorithm implemented on an Arduino UNO microcontroller. The system is first modelled in MATLAB/Simulink, where the PID gains are manually tuned by iterating over Kp, Ki, and Kd and evaluating the closed-loop rise time, overshoot, settling time, and steady-state error as the tuning criteria, then validated on a physical test bench comprising two centrifugal pumps — one operating as the pressurised hydraulic supply and the other as the PAT driving the SEIG. The experimental setup is documented in full, including schematic and photographic evidence. Results show that the proposed ELC constrains the terminal voltage deviation to within ±3% of the 230 V reference under load-switching transients up to 600 W, with settling times of 100 ms (load shedding) and 180 ms (load acceptance). Without ELC, the uncontrolled system exhibited a peak voltage deviation of 25.9% and a frequency excursion of 16.3% across the full load range. Total harmonic distortion (THD) increased by only 0.037 percentage points when the ballast driver was active, from 0.880% to 0.917%. Both values remained below the 8.0% voltage THD reference limit specified by IEEE Std 519-2022 for systems with a PCC voltage of (V\leq1) kV. The total component cost of the control card was low, confirming the economic viability of the solution for remote micro-hydropower electrification.
Keywords
- pump-as-turbine (PAT)
- self-excited induction generator (SEIG)
- PID control
- electronic load control (ELC)
- pulse-width modulation (PWM)
Project Number
References
- Gulaydin O, Mourshed M. Net-zero Turkey: renewable energy potential and implementation challenges. Energy Sustain Dev. 2025;87:101744. https://doi.org/10.1016/j.esd.2025.101744
- Bulut M, Öz İ. Operational challenges and multiple solutions for high renewable energy penetration in the Turkish power grid system. Int J Energy Stud. 2026;11(1):631-651. https://doi.org/10.58559/ijes.1888994
- Kumar S, Sireesha B, Singh JG, Salam PA. Low-head pico-hydro plant using the pump as turbine (PaT) and permanent magnet synchronous generator (PMSG) for isolated loads: experimental studies. Int Energy J. 2023;23(3):131-140. https://doi.org/10.64289/iej.23.0309.1031387
- Nasir A, Salau AO, Dribssa E, Girma M. Technical and economic analysis of a pump as a turbine for rural electrification. Int J Sustain Energy. 2023;42(1):914-928. https://doi.org/10.1080/14786451.2023.2244606
- Harvey A, Brown A, Hettiarachi P, Inversin A. Micro-hydro design manual: a guide to small-scale water power schemes. London: Intermediate Technology Publications; 1993. ISBN: 1853391034.
- Jemal AN, Haile MG. Comprehensive review of pump as turbine (PAT). J Renew Energy Sustain Dev. 2019;5(2):68-79. https://doi.org/10.21622/resd.2019.05.2.068
- Catelas JMR, Fernandes JFP, Pérez-Sánchez M, López-Jiménez PA, Ramos HM, Branco PJC. Energy efficiency and stability of micro-hydropower PAT-SEIG systems for DC off-grids. Energies. 2024;17(6):1382. https://doi.org/10.3390/en17061382
- Nyirenda EJ, Kihedu JH, Kimambo CZM, Nielsen TK. Optimization pump as turbine coupled to a self-excited induction generator using multi-objective genetic algorithm. Tanzan J Eng Technol. 2024;43(1):133-143. https://doi.org/10.52339/tjet.v43i1.983
Details
Primary Language
English
Subjects
Automotive Engineering (Other)
Journal Section
Research Article
Authors
Osman Fırat Alkan
0000-0002-7704-8796
Türkiye
Sibel Akkaya Oy
*
0000-0002-1209-920X
Türkiye
Seyfettin Vadi
0000-0002-4244-9573
Türkiye
Publication Date
October 18, 2026
Submission Date
May 8, 2026
Acceptance Date
October 2, 2026
Published in Issue
Year 2026 Volume: 10 Number: 3
