Transient Stability and Steady State Stability

Transient Stability

Transient Stability is the ability of a power system to return to its normal state after a major disturbance, such as a fault or a disconnection or connection of a large load.

When there is a disturbance in the system, there are oscillations.  These oscillations are called swings.  Transient stability analysis is concerned with the response of the power system to such oscillations.    A power system with proper response will bring the system back to steady state operations within a short period of time.

Steady State Stability

Steady State Stability is the ability of a power system to respond to slow or gradual changes in its operating parameters.  When a number of power sources and loads are connected to a system, there will be gradual shifting of loads from one generator to another.  These oscillations, if not properly controlled, can develop into large oscillations which can cause bigger disturbances.

BH Analyzer

The B-H Analyzer is an instrument which can measure and plot the B-H curve of a given material.  They can also be used to determine the core loss at high frequency.

BH analyzers are used to analyze the behavior of circuit components at different frequencies.  The B-H curves are plotted across a wide frequency spectrum.

BH Analyzers are also used to determine the permeability of materials used in the construction of electric machines.

Coercivity

Coercivity is the strength of the magnetic field required to demagnetise a ferromagnetic material.  It is also described as the ability of a material to resist demagnetization.

Materials with high coercivity are made into permanent magnets, such as Alnico.  The unit of coercivity is ampere/meter.

Materials with low coercivity are made into electromagnets, such as soft iron.

The coercivity can be calculated from the B-H curve of a material.  The horizontal distance between points b and a in the BH curve in the right is the coercivity

The unit of coercivity is Ampere/metre

Arduino - An Overview

Arduino is an open source platform used in embedded systems. Arduino has its own hardware and software. Since it is an open source project, it is used for numerous projects by many hundreds of people around the world.  The Layout and the production files are available in the public domain.

The Arduino board is powered by the Atmel 8-bit AVR microcontroller.  The Flash memory and other features may vary among different boards.

Programming the Arduino
The program for the Arduino can be written in any high level programming language with a compiler which can generate machine level code for Arduino.  However, Arduino has its own IDE (Integrated Development Environment).  The Arduino can be used using the IDE.  A program for the Arduino is called the sketch.

Programs can be written using the C and C++ language

Arduino has a well developed ecosystem consisting of numerous manufacturers and developers.  Many professional projects can be built with Arduino.  There are many peripherals such as sensors and actuators which can be linked to the Arduino to create a range of products from robots to security systems.

Many manufacturers and hobbyists create projects based on Arduino.

Useful Links

Arduino.cc

Software, Hardware and Firmware

Software refers to the non physical parts of a computing system.  Examples are the programs which contain the instructions.  The software is written in the programming language such as VB, Java and C

Firmware is the program written on an embedded device such as a microprocessor or a microcontroller.  It controls the functioning of the microprocessor IC

It is written in the assembly level language. It is called firmware as it interfaces between the software and the hardware.

Hardware refers to the physical components of a computing system such as the processor, memory and the peripherals.

Difference between a microprocessor and a microcontroller

The key difference is that in a microcontroller, the memory (ROM and RAM) and the peripherals are fabricated on a single IC. A microprocessor, on the other hand, does not contain the memory and the peripherals in itself.  They are separately mounted and connected.

Microcontrollers are used for specific operations, such as to control and operate a washing machine or a traffic signal.  A microprocessor can be installed for a specific function in a larger system.  It is not designed for a single operation.

The speed of a microprocessor is above 1 GHz while the speed of the microcontroller is around 50 MHz.

Microprocessors can handle greater complexity as compared to microcontrollers.   They also use more power than microcontrollers.

Embedded Electronics - An Overview

Embedded Electronics, as the name suggests, refers to electronic hardware and software that is embedded or attached to the equipment being controlled.  

The component may be a robotic arm in an assembly line or a life support device in an ICU.  Today, Embedded Electronics can be found in all areas of life.  The washing machine and the refrigerator at home are also controlled by embedded electronics.

The advantages of embedded systems are their small size, low cost and power consumption and their rugged construction.  The program and the logic of machine operation can be easily modified.  The cost of embedded systems are lower as they are mass produced which reduces cost.  

Embedded systems can be built using both microprocessors and micro controllers.  Embedded systems can be used as standalone units or as part of a larger network controlling a bigger system.  

Programming Embedded Systems

Embedded systems can be programming using assembly level languages.  The assembly level languages are compiled into machine level using compilers.  The program is stored in the nonvolatile memory of the system.  Microprocessors and microcomputers will have their own programming languages specified by the manufacturers.  A good understanding of the C programming language will be useful in programming embedded systems.