HV DC Load Impedance Measurement Using AC Signal Injection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power supplies struggle to accurately measure the impedance or capacitance of loads connected to high-voltage DC power supplies, particularly in electrostatic chucks, due to limitations in current measurement methods and flexibility in power supply configurations.
Innovation Solution
A power supply system that includes a current sensor, voltage sensor, and source conductor, coupled with a micro-controller, to generate and process alternating signals for precise calculation of load impedance or capacitance, using a sinewave oscillator and blocking inductors to manage current flow and a quadrature demodulator for phase analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional current measurement methods are used in high-voltage DC power supplies, then the power supply can operate with simpler measurement circuits, but the measurement precision of load impedance or capacitance is insufficient
Solution Approach 1:
The patent introduces an intermediary AC signal injection method where a small AC signal is superimposed on the DC high-voltage output. This AC signal acts as a mediator that enables precise impedance measurement through its interaction with the load, allowing the system to measure capacitance or impedance values that would be difficult to obtain with conventional DC measurement methods alone
Solution Approach 2:
The patent replaces conventional direct DC current measurement methods with an AC-based measurement approach. By injecting an AC signal and measuring the resulting current response, the system substitutes a more sophisticated electrical measurement mechanism that provides higher precision for impedance and capacitance characterization
2Adaptability or versatility
If the power supply uses fixed configuration for electrostatic chuck operation, then the circuit design is simpler, but the adaptability to different electrostatic chuck configurations is limited
Solution Approach 1:
The patent implements a universal power supply configuration that can accommodate different electrostatic chuck types (Coulomb and J-R types) and configurations (monopolar, bipolar, multipolar). The measurement circuit is designed to universally handle various operational modes by detecting impedance characteristics across different terminal configurations, making the power supply adaptable without requiring separate dedicated circuits for each chuck type
Solution Approach 2:
The patent introduces dynamic measurement capabilities where the system can adaptively adjust measurement parameters based on the detected load configuration. The measurement circuit dynamically responds to different electrostatic chuck configurations by detecting impedance variations and adjusting measurement frequency or amplitude accordingly, enabling versatility across different operational scenarios
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
Enables accurate and efficient monitoring of load impedance or capacitance, improving measurement precision and flexibility across various electrostatic chuck configurations.
Implementation Method 1
a sinewave oscillator adapted for generating a sinusoidal voltage at a predetermined frequency
Implementation Method 2
a first blocking inductor connected between a first output of the first electric generator and a first lead of the load, and a second blocking inductor connected between a second output of the second electric generator and a second lead of the load
Data Source
AI summary
A power supply comprises a current sensor that measures an oscillating current through a load connected to the power supply, a voltage sensor that measures an oscillating voltage across the load, and a source conductor that transmits the sinusoidal voltage generated by a sinewave oscillator. A micro-controller is coupled to the current sensor, the voltage sensor, and the source conductor. The micro-controller computes the impedance or capacitance of the load by using digital data derived from the three sensors.