Voltage Compensation Device Using Rotating Coordinate Transformations
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Solution Overview
Problem
In power systems, voltage drops occur due to increasing power line impedance with distance from the substation, necessitating a device that can maintain constant voltage levels regardless of distance.
Innovation Solution
A voltage compensation device featuring a power converter with a self-arc-extinguishing inverter circuit, series transformers, and a controller that generates drive signals based on phase voltages to continuously compensate system voltage, utilizing rotating coordinate transformations and arithmetic parts to calculate compensation amounts for normal and reverse-phase components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional voltage compensation methods are used, then voltage stability can be maintained, but the response speed is slow and compensation is not continuous
Solution Approach 1:
The patent replaces conventional mechanical voltage regulation methods with an electronic power converter system using self arc-extinguishing switching elements. This substitution enables continuous and rapid voltage compensation by electronically controlling the switching elements to generate compensation voltages that are immediately applied to the power line, eliminating the slow response inherent in mechanical systems.
Solution Approach 2:
The patent implements dynamic voltage compensation by continuously adjusting the compensation voltage based on real-time detection of system voltage conditions. The controller dynamically modifies the drive signals to the switching elements, allowing the compensation amount to vary continuously and rapidly in response to changing voltage conditions, thereby achieving both high speed and continuous operation.
2Measurement precision
If complex control systems are used to achieve precise voltage compensation, then voltage accuracy improves, but device complexity increases
Solution Approach 1:
The patent segments the voltage compensation control into distinct functional modules: a detection unit that monitors system voltage, a calculation unit that determines compensation amounts based on detected voltages, and a control unit that generates drive signals for switching elements. This segmentation allows each module to perform its function with high precision while keeping the overall controller structure organized and manageable, reducing complexity.
Solution Approach 2:
The patent introduces coordinate transformation circuits as intermediary components that simplify the control architecture. These circuits transform three-phase voltage measurements into rotating reference frame components, enabling precise voltage compensation calculations through standardized mathematical operations. This intermediary transformation layer decouples the complexity of three-phase control from the basic control logic, improving precision without proportionally increasing overall device complexity.
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
The device effectively maintains voltage within a target range, addressing voltage drops and unbalanced states, with continuous and precise compensation, reducing system complexity and cost compared to existing solutions.
Implementation Method 1
an inverter circuit including a switching element that is of a self arc-extinguishing type
Data Source
AI summary
A voltage compensation device according to an embodiment includes a controller including first and second coordinate transformation circuits, and first and second arithmetic parts. The first coordinate transformation circuit generates first and second outputs that are mutually-orthogonal by performing a rotating coordinate transformation of the normal-phase components of a three phase AC. The first arithmetic part calculates a system voltage based on a DC component of the first output and generates a first compensation amount corresponding to a compensation voltage set to compensate a shift of the system voltage from a preset target voltage. The second coordinate transformation circuit generates third and fourth outputs that are mutually-orthogonal by performing a rotating coordinate transformation of reverse-phase components of the three-phase AC. The second arithmetic part generates second compensation amount of a reverse-phase component of the system voltage based on DC components of the third and fourth outputs.