Noise measurement system in power stabilization network, variable filter applied to the same, and method for measuring noise in power stabilization network
A noise measurement system in a power stabilization network, a variable filter applied to the power stabilization network, and a method for measuring noise in the power stabilization network are provided. A power line communication signal from the power stabilization network is attenuated relative to a particular frequency using a filter in order to allow the power line communication signal to operate within an input range of an Electromagnetic Interference (EMI) measurer. A signal from a forbidden frequency band is transmitted to the EMI measurer without any attenuation or influence on a noise floor.
1. A noise measurement system comprising:
a power stabilization network including a power input unit configured for receiving external power, a power output unit configured for supplying power to a power line communication modem and an output unit for use of a measurement instrument;
a filter connected to the output unit and configured for selecting and attenuating a signal inputted from the output unit in response to information on a forbidden frequency band; and
an Electromagnetic Interference (EMI) measurer connected to the filter.
2. The system of claim 1 , wherein the filter is a high pass filter.
3. The system of claim 1 , wherein the filter is a variable filter.
4. The system of claim 3 , wherein the variable filter comprises:
a filter input unit connected to the power stabilization network;
a variable filter unit connected to the filter input unit;
an information input unit configured for inputting the information on the forbidden frequency band; and
a controller configured for setting up a number of frequencies of the variable filter unit in response to the information on the forbidden frequency band.
5. The system of claim 4 , wherein the variable filter further comprises a display unit configured for displaying a state of the forbidden frequency band in response to an instruction from the controller.
6. The system of claim 4 , wherein the variable filter further comprises a filter output unit connected to the EMI measurer.
7. The system of claim 1 , wherein the EMI measurer includes an attenuator.
8. The system of claim 1 , wherein the EMI measurer is configured for correcting a final measured value from the EMI measurer according to a forbidden frequency band attenuation rate when the forbidden frequency is below 525 kHz.
9. A method for measuring noise in a power stabilization network, the method comprising:
supplying power to the power stabilization network;
selecting and attenuating, using a filter, a region other than a forbidden frequency band relative to a signal output from an output unit for use of a measurement unit; and
measuring, by an EMI measurer, signal with noise removed from the signal.
10. The method of claim 9 , wherein the selecting and attenuating the region other than the forbidden frequency band is performed via a variable filter.
11. The method of claim 10 , wherein selecting and attenuating the region other than the forbidden frequency band further comprises:
setting up the forbidden frequency band using a user input unit.
12. The method of claim 9 , wherein measuring the signal comprises:
correcting, by the EMI measurer, a final measured value from EMI measurer according to a forbidden frequency band attenuation rate when a frequency is below 525 kHz.