Variable Frequency Drive Power Module Filtering
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Solution Overview
Problem
Existing systems for providing electrical power to downhole oil production equipment, such as electric submersible pumps, experience noise and voltage overshoot due to rapid voltage changes in PWM signals from serially connected power cells, which can be harmful to the pump motor and require costly filtering solutions.
Innovation Solution
The system involves individually filtering the output signals of multiple power modules before combining them to produce a high-voltage output for the pump motor, using filters like LC filters to reduce high-frequency components and minimize voltage changes, thereby reducing noise and stress on the motor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If serially connected power cells are used to generate high output voltages, then the desired high-voltage output is achieved, but the rate of rise of output voltage becomes much larger causing more noise and voltage overshoot at the pump motor
Solution Approach 1:
The patent divides the power generation into multiple independent power modules (first, second, third power modules) connected in series. Each module generates a portion of the total output voltage, allowing the overall high voltage to be achieved through summation of individual module outputs rather than a single large voltage step, thereby reducing the rate of voltage rise and associated noise
Solution Approach 2:
The patent implements individual filtering for each power module's output signal before the signals are combined. By pre-filtering high-frequency components at each module level rather than filtering the combined high-voltage signal, the system reduces noise and voltage overshoot before they propagate to the pump motor, while also making the filtering process more manageable and cost-effective
2Object-affected harmful factors
If individual filtering is applied to each power module output, then noise and high-frequency components are reduced, but the system complexity and number of filters increase
Solution Approach 1:
The filtering function is segmented and distributed across multiple independent power modules. Each module has its own filter, allowing filtering to be performed at lower voltage levels individually rather than requiring a single complex filter at the high-voltage output. This distribution simplifies each individual filter's design while achieving overall noise reduction
Solution Approach 2:
The patent introduces individual filters as intermediary components between each power module and the combination point. These filters act as mediators that remove high-frequency noise from each module's output before the signals are summed, preventing noise propagation to the pump motor while maintaining system modularity
3Power
If multiple power modules are connected in series, then the maximum output voltage is reached in a single step, but this causes larger dv/dt leading to more noise and motor stress
Solution Approach 1:
The patent segments the voltage generation into multiple power modules connected in series, where each module contributes a portion of the total voltage. The individual filtering of each module's output smooths the voltage transitions, effectively reducing the overall dv/dt when the modules are combined, thereby protecting the motor from excessive voltage stress and noise
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces noise and voltage overshoot at the pump motor, decreases the stress on system components, and lowers the cost and complexity of filtering by handling lower voltages at each module rather than the full high-voltage output, resulting in a more efficient and cost-effective power delivery.
Implementation Method 1
Each of the power modules is configured to receive an input power signal and to provide a corresponding output power signal. The output power signal of each power module is filtered to remove at least a portion of high-frequency components in the output power signal.
Data Source
AI summary
Systems and methods for providing electrical power and to downhole oil production equipment such as electrical submersible pumps, wherein the outputs of multiple power modules are individually filtered before being added together to obtain a high voltage output that is provided to the downhole equipment. In one embodiment, an electrical drive system includes multiple power modules and corresponding filters. Each of the power modules is configured to receive an input power signal and to provide a corresponding pulse width modulated or stepped intermediate signal. The signal output by each power module is individually filtered to remove at least a portion of high-frequency components in the signal. The power modules and filters are coupled together in a configuration in which the filtered signals of the power modules are added to produce an output drive signal that is used to drive equipment such as an electrical submersible pump.