Lab task # 01 What is digital signal processing
Lab task # 01
What is digital signal processing ?
Signal processing as the name suggest receiving signal and process them. Before receiving and processing a signal first of all we should know what is signal ?
Anything which carries Information is a signal like as : Human voice, motion, gesture, traffic light signal and so on.
DSP deals with the processing of any real- world signal through digital computers. Computer can store, process and transmit information using digital data. The word processing mean to manipulate as well as to transmit or modify something. Moreover, Digital signal processing perform signal processing using digital techniques with the help of some hardware or some other kinds of digital computers.
What is the application of Digital Signal processing related to Electrical Engineering ?
Here are the few application of DSP like as : Digital Image processing, Audio signal Processing , Image video compression, digital communication, digital synthesizers, radar, sonar and bio medical imaging & signaling Analysis ( MRI,CAT, ECG, EEG, Cardiac pacemaker, Brain chip, Artificial Eye).
Application of DSP in Electrical Engineering
The DSP can handle different wireless communication and power line communication (PLC) protocols in real time as well as smart-power algorithms while the general-purpose processor can run a high-level operating system and application processing.
Smart-grid systems consist of different applications requiring DSPs to do real-time signal analysis of the power waveforms anywhere on the grid and to transmit the information, including signal quality, fault conditions, transmission losses and power consumption, to the substation.
Real-time DSP functions include the following:
Precision power analytics
Frequency domain analytics
Time domain analytics
Rogowski digital integrator
Power line communication
DSP-based digital integrator
A key component enabling smart-grid power analytics is the integrator, which detects the 50- or 60-Hz rms-current from a current sensor device, such as a Rogowski coil. The advantage of a Rogowski coil is the current can be measured without having to make an incision onto the power cable, as it is normally being done when using current transformers (CT).
A DSP-based digital integrator performs better than an analog-based integrator in low frequency noise rejection, minimum phase error over the entire frequency band, and providing wide dynamic range.
Power line communication (PLC)
PLC is the preferred method for service providers to communicate with the electric meters installed at the remote sites because the advanced metering infrastructure only requires a moderate data rate to service a large number of residences and businesses. One of the biggest concerns is interference with other wireless networks.
The number one advantage that DSP-based PLC designs have over other implementations, such as an application-specific integrated circuit (ASIC), is that standards vary from country to country, so it is crucial to have a design that supports many different formats and protocols.
Accurate measurements of electrical systems are essential to the development and stability of the smart grid. These measurements are used to detect symptoms of poor power quality in the grid. Phenomena can lead to false tripping of relays, blown fuses, and failure of electrical equipment, among other problems. Moreover, identifying and eliminating poor power quality can lead to a significant reduction in revenue waste.
Electric metrology involves the measurement of parameters such as rms current and voltage, reactive, active and apparent power components and the frequency of a power signal. Often, the calculation of these metrology parameters involves the use of several multiply-and-accumulate operations.
More applications are now requiring higher precision and faster response times meaning a floating-point DSP is better suited for the task.
A power-quality monitor system must be capable of detecting abnormalities such as voltage swells and dips, surges and transients, short interruptions, and harmonics. The presence of harmonics can lead to overheated transformers, false tripping of relays and even lighting flicker detectable by the human eye. One method of identifying the harmonics present in a power signal is through the use of discrete fast-Fourier transforms (DFT) or FFT.
When an FFT or DFT is applied to the input power signal, its output can be used to identify the different frequencies that are present in the input signal. A DSP is very efficient at performing FFTs and DFTs due to its specialized multiply-and-accumulate instructions.