HVDC Voltage Sensor Using Composite Insulator and Segmented Dividers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current high voltage direct current (HVDC) line voltage sensors, particularly RC dividers, face limitations in temperature stability, accuracy for direct and alternating currents, and harmonic measurements at frequencies up to 5kHz, and are prone to internal insulation faults, restricting their application to voltages below 800kV.
Innovation Solution
A direct current very high voltage line voltage sensor comprising two voltage division stages connected in series, with each stage featuring capacitors and resistors in parallel, housed within a composite insulator, and an electronic circuit for signal processing, including temperature correction, to maintain accuracy and stability across a wide voltage range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RC dividers are manufactured using capacitive components based on paper/polypropylene - SF6 gas insulation techniques under high SF6 gas pressure, then voltage measurement capability is achieved, but internal insulation faults occur and temperature stability and measurement accuracy are insufficient
Solution Approach 1:
The patent replaces the SF6 gas insulation environment with dry air at atmospheric pressure. The composite insulator housing provides mechanical support and electrical insulation, eliminating the need for pressurized SF6 gas. This inert environment replacement resolves the contradiction by providing reliable insulation through the solid composite material while improving temperature stability and measurement accuracy by eliminating gas pressure-related instabilities and environmental sensitivity.
Solution Approach 2:
The patent employs composite insulator materials combining multiple materials with complementary properties to achieve both reliable insulation and stable measurement performance. The composite structure integrates materials optimized for electrical insulation, mechanical strength, and thermal stability, thereby simultaneously improving reliability and measurement precision without requiring pressurized gas environments.
2Adaptability or versatility
If voltage dividers are designed for frequency-independent voltage division using RC components, then AC voltage measurement capability is achieved, but temperature stability and AC harmonic measurement accuracy up to 5 kHz are insufficient
Solution Approach 1:
The patent optimizes the RC component parameters (resistance and capacitance values) to achieve frequency-independent voltage division across the extended frequency range up to 5 kHz. By carefully selecting and matching the time constants of the RC networks in the voltage divider stages, the system maintains accurate measurement of AC harmonics while improving temperature stability through compensated component selection and arrangement.
3Measurement precision
If voltage dividers operate at very high voltages above 800 kV, then measurement capability is extended, but internal insulation faults increase
Solution Approach 1:
The patent divides the high-voltage measurement system into multiple series-connected voltage division stages, each operating at a lower voltage stress level. This segmentation of the voltage divider into discrete stages with intermediate grounding or shielding reduces the electrical stress on any single insulating component, thereby preventing internal insulation faults while enabling measurement of very high voltages exceeding 800 kV.
Solution Approach 2:
The patent introduces intermediate voltage tapping points and shielding structures between the high-voltage line and the measurement circuit. These intermediary elements serve as electrical buffers and field shields, reducing direct insulation stress on the measurement system while maintaining accurate voltage measurement capability across the extended voltage range.
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 solution provides precise and stable voltage measurement across a broad range of frequencies and voltages, from 100kV to 1100kV, with improved temperature stability and accuracy, enabling reliable protection, control, and energy metering in HVDC systems.
Implementation Method 1
each impedance Zi (i=1, 2) is then composed of a resistor Ri (i=1, 2) and a capacitor Ci (i=1, 2) connected in parallel
Implementation Method 2
Each impedance Zi (i=1, 2) is then composed of a resistor Ri (i=1, 2) and a capacitor Ci (i=1, 2) connected in parallel
Implementation Method 3
the first electrically conductive plate and the second electrically conductive plate each being surrounded by an electrically conductive cover, at least one electrically insulating retaining piece that clamps the resistor and capacitor
Implementation Method 4
The voltage (Vb-Vo) measured by the voltage divider is a reflection of the voltage (Va - Vo) present on the line
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a very high voltage DC line voltage sensor, the sensor being made up of a voltage divider comprising two series-connected voltage division stages, a first voltage division stage (E1) being made up of at least two elementary voltage division stages (Em) arranged in series and distributed in a composite insulator (I), each elementary stage (Em) comprising at least one capacitor (Ce) and at least one resistor (Re) in parallel that are fixed to electrically conductive plates (a1, a2), at least one electrically insulating holding piece (S) that encloses the resistor and the capacitor being in contact with the internal wall of the composite insulator (I) in order to fix the capacitor and the resistor to the inside of the composite insulator.