**Abstract:**
This paper highlights the limitations of traditional power supply systems used in submersible electric pumps and emphasizes the advantages of variable frequency power supply. It outlines specific requirements and solutions for inverters used in submersible pump applications. 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 oil field equipment with advanced technology is a growing trend. Integrating modern control and frequency regulation technologies into submersible pumps is a key part of this transformation. Most submersible pumps operate at 1140V or 2300V, and they are placed deep underground (1000 to 3000 meters), where conditions are extremely harsh—high temperature, strong corrosion, etc. Traditional power supply methods, such as full voltage and fixed frequency, often lead to frequent failures and high operating costs. Repairing a damaged submersible pump can cost up to 50,000 yuan, and replacing the cable alone may cost around 100,000 yuan. On average, each pump requires maintenance every 10 months, costing about 80,000 yuan. These issues highlight the need for a more reliable and efficient power supply system.
Traditional power supply systems have several disadvantages:
- The pump runs at full speed, which can cause cavitation when the well liquid level is low.
- Full-voltage starting results in high inrush current and torque, shortening motor life.
- Voltage fluctuations in the oil field can cause overvoltage or undervoltage, damaging the motor.
- Long underground cables cause significant voltage drop, affecting motor performance.
To address these challenges, an ideal power supply should offer:
- Soft start and variable frequency operation for better control.
- Compensation for voltage fluctuations and line losses.
- Sinusoidal output to prevent motor damage from voltage spikes.
- Comprehensive protection features.
- Easy control and clear display.
Conventional inverters are not suitable due to mismatched voltage levels and non-sinusoidal outputs. Our company has successfully developed a 1140V, 30–100kW submersible pump inverter series. Now, we are working on a dedicated 2300V inverter for submersible pumps.
**II. Development of Special Inverter**
Although submersible pumps operate at different voltages, most run at 1140V or 2300V. While some use 380V inverters with step-up transformers, this approach has inherent drawbacks, such as increased complexity and cost. With advancements in IGBT technology, high-voltage inverters no longer require transformers. Our 1140V inverter has been successfully deployed in oil fields, proving its effectiveness. This paper discusses the design and performance of the new 2300V submersible pump inverter.
Key technical specifications include:
- Input: 2300V, 50Hz
- Output: 2300V, 110kW
- Frequency range: 2–50Hz
- Output waveform: Sine wave with harmonic suppression
- Cable loss compensation
The inverter uses a three-level circuit to reduce voltage stress on power devices and improve waveform quality. It employs Siemens IGBT modules (1700V, 200A) and includes dynamic voltage balancing circuits to ensure even distribution across series-connected IGBTs. A low-pass LC filter is used to smooth the output and prevent motor damage from high-frequency PWM signals. The inverter also compensates for voltage drops along long cables, ensuring stable motor operation.
**III. Operation and Results**
The 2300V submersible pump inverter has been successfully developed and tested. It meets all design specifications and performs well under rated load. Steady-state voltage imbalance is within 10%, and dynamic imbalance is below 15%. The output waveform is nearly sinusoidal, and the motor operates smoothly at low speeds and light loads. The inverter provides excellent control, making it a reliable solution for submersible pump applications.
SHAOXING KEQIAO FANEVER IMPORT AND EXPORT CO., LTD , https://www.sxfanever.com