Power Measurement Device Using Intermediate Frequency Conversion
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Solution Overview
Problem
Conventional power measurement devices, such as inductive watt-hour meters, struggle to convert analog power consumption values into digital information effectively, hindering smooth information exchange between power providers and users in smart grid systems.
Innovation Solution
A power measurement device that includes a detection part for current and voltage detection, a frequency control part to convert fundamental frequencies to intermediate frequencies, and a conversion part using sigma-delta modulation and down converters to generate digital values, which are then used to calculate wattage, thereby improving measurement precision and enabling digital information exchange.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If analog-digital converter is added to convert power consumption to digital information, then information exchange capability is improved, but device complexity increases
Solution Approach 1:
The patent combines the frequency control function and analog-digital conversion function into a single integrated circuit device. The frequency control part generates intermediate frequency signals, and the conversion part converts these signals to digital values, merging multiple functions into one component to reduce overall system complexity while maintaining digital information exchange capability
Solution Approach 2:
The power measurement device is designed as a multi-functional integrated circuit that performs frequency control, analog-digital conversion, and power measurement tasks simultaneously. This universal device replaces the need for separate analog-digital converter modules, reducing device complexity while enabling digital information exchange
2Measurement precision
If frequency control part converts fundamental frequency to intermediate frequency, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The frequency control part is integrated within the power measurement device, combining frequency conversion and measurement functions in a single unit. This integration reduces the number of external components needed while maintaining the precision benefits of intermediate frequency conversion
Solution Approach 2:
The intermediate frequency acts as an intermediary signal between the fundamental frequency input and the digital output. By converting to intermediate frequency first, the system achieves better measurement precision while the integration of this conversion process within the measurement device minimizes the added 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 achieves precise power measurement by reducing noise interference from DC offset and flicker noise, enhancing signal-to-noise ratio and allowing for accurate digital communication of power consumption data, thus improving measurement precision and simplifying digital filter design.
Implementation Method 1
a frequency control part configured to transit a fundamental frequency by the supply current and the supply voltage to an intermediate frequency
Implementation Method 2
a first sigma-delta modulation part configured to convert the supply current having the intermediate frequency supplied from the frequency control part into the digital current value
Data Source
AI summary
Provided is a power measurement device including a detection part configured to detect a supply current and a supply voltage from a commercial alternating current power supply, a frequency control part configured to transit a fundamental frequency by the supply current and the supply voltage to an intermediate frequency, a conversion part configured to generate a digital current value and a digital voltage value of the supply current and the supply voltage having the intermediate frequency applied from the frequency control part and transit the intermediate frequency to the fundamental frequency again, and a calculation/control part configured to calculate wattage using the digital current value and the digital voltage value, which are output signals of the conversion part.