**Abstract:**
This paper highlights the limitations of traditional power supply systems used in submersible electric pumps and emphasizes the advantages of implementing a variable frequency power supply. It outlines specific requirements and solutions for inverters designed for submersible pumps. Following the successful deployment of a 1140V submersible pump inverter recognized by oil fields, Scene Electronics has now developed a dedicated 2300V inverter for submersible pumps.
**I. Introduction**
Modernizing existing oilfield equipment with advanced technology is a growing trend. Integrating modern control and frequency regulation technologies into submersible pumps is a critical step in this transformation. Submersible pumps typically operate at 1140V or 2300V, placed deep underground (1000–3000 meters), where harsh conditions such as high temperature and corrosion lead to frequent failures. Traditional full-voltage, fixed-frequency power supplies result in high maintenance costs—repairing a single pump can cost up to ¥50,000, and cables need replacement every few months. The drawbacks of traditional power supplies include excessive starting current, motor damage due to voltage fluctuations, and significant line losses over long cables. To address these issues, an ideal power supply must offer soft start, variable frequency control, voltage compensation, and reliable protection. Inverters are the best solution, but standard drives are unsuitable due to voltage mismatch and waveform distortion. Scene Electronics has successfully developed a 1140V, 30–100kW inverter series and is now working on a 2300V version.
**II. Development of a Specialized Inverter**
While submersible pumps operate at different voltages, most use 1140V or 2300V. Some systems use a 380V inverter with a step-up transformer, but this approach introduces inefficiencies and higher costs. With the advancement of IGBT technology, it's now possible to design inverters without transformers. The company’s 1140V inverter has performed well in the field, prompting the development of a 2300V model. This inverter features a three-level circuit to reduce harmonic distortion and dv/dt, using Siemens dual-cell IGBT modules (1700V, 200A). A dynamic voltage equalization circuit ensures stable operation during switching. The carrier frequency is set at 3.4kHz to balance waveform quality and switching loss. Input voltage stability is achieved through a feedback system that adjusts PWM pulse width based on grid fluctuations. An LC low-pass filter is used to smooth the output waveform and prevent motor damage from cable reflections. Cable loss compensation is handled via a software-based adaptive voltage adjustment process.
**III. Operation**
The 2300V inverter has been successfully tested and meets all design specifications. It runs smoothly under rated load, with steady-state voltage imbalance within 10% and dynamic imbalance below 15%. The output waveform remains nearly sinusoidal across the entire frequency range, ensuring smooth motor operation at low speeds and light loads. The system demonstrates excellent performance, making it a reliable solution for submersible pump applications.
SHAOXING KEQIAO FANEVER IMPORT AND EXPORT CO., LTD , https://www.sxfanever.com