Page 15 - Modern Control Systems

Preface

MODERN CONTROL SYSTEMS—THE BOOK

Global issues such as climate change, clean water, sustainability, waste management,
emissions reduction, and minimizing raw material and energy use have caused many
engineers to re-think existing approaches to engineering design. One outcome of
the evolving design strategy is to consider green engineering.The goal of green engi-
neering is to design products that minimize pollution, reduce the risk to human
health, and improve the environment. Applying the principles of green engineering
highlights the power of feedback control systems as an enabling technology.
To reduce greenhouse gases and minimize pollution, it is necessary to improve
both the quality and quantity of our environmental monitoring systems. One exam-
ple is to use wireless measurements on mobile sensing platforms to measure the
external environment. Another example is to monitor the quality of the delivered
power to measure leading and lagging power, voltage variations, and waveform har-
monics. Many green engineering systems and components require careful monitor-
ing of current and voltages. For example, current transformers are used in various
capacities for measuring and monitoring current within the power grid network of
interconnected systems used to deliver electricity. Sensors are key components of
any feedback control system because the measurements provide the required infor-
mation as to the state of the system so the control system can take the appropriate
action.
The role of control systems in green engineering will continue to expand as the
global issues facing us require ever increasing levels of automation and precision. In
the book, we present key examples from green engineering such as wind turbine
control and modeling of a photovoltaic generator for feedback control to achieve
maximum power delivery as the sunlight varies over time.
The wind and sun are important sources of renewable energy around the world.
Wind energy conversion to electric power is achieved by wind energy turbines con-
nected to electric generators. The intermittency characteristic of the wind makes
smart grid development essential to bring the energy to the power grid when it is
available and to provide energy from other sources when the wind dies down or is
disrupted. A smart grid can be viewed as a system comprised of hardware and soft-
ware that routes power more reliably and efficiently to homes, businesses, schools,
and other users of power in the presence of intermittency and other disturbances.
The irregular character of wind direction and power also results in the need for reli-
able, steady electric energy by using control systems on the wind turbines them-
selves. The goal of these control devices is to reduce the effects of wind
intermittency and the effect of wind direction change. Energy storage systems are
also critical technologies for green engineering. We seek energy storage systems that
are renewable, such as fuel cells. Active control can be a key element of effective
renewable energy storage systems as well.

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