In recent times, building supply stores across the globe
have seen some sweeping changes, especially in the garden appliance and power
tool sections, for products such as saws, drills, lawnmowers, and vacuum
cleaners among others.
The first major change which was introduced to the global power
tools market was the cordless devices that were powered through portable
batteries. This was followed by the inclusion of technological innovations such
as brushless direct current motors and full-bridge drivers for brushed motors,
which were aimed towards extending battery life and adopting very complex
schemes for equipment control that integrated sensors with power drivers and
controllers to manage switching sequences seamlessly.
Furthermore, recent innovations even provide power tools to
be tracked wirelessly through a form of low energy Bluetooth connectivity,
providing end-users with easier tracking of inventory and deterring theft of
valuable devices. In the latest development, manufacturers have made
revolutionary changes in the core design of microcontrollers and motor-control
algorithms, which are increasingly being incorporated into various power tool
designs.
Field Oriented
Control Changes Brushless Direct Current Control Methods
Unlike brushed motors that make use of permanent-magnet
stators, mechanical commutation, and wound armature, the brushless direct
current (BLDC) stators comprise windings that are sequentially powered to generate
a rotating electro-magnetic field. The BLDC rotor follows the movement of this
field acting as a permanent magnet. Standard configurations comprise 6 symmetrical
coils that are arranged into 3 distinct phases at intervals of 120-degrees.
The BLDC system is essential for switching electrical
currents to the windings in a sequential manner for maintaining the movement of
the rotor, which can be achieved with either trapezoidal commutation, or
sinusoidal control, or the newest method which makes use of electro-magnetic
field oriented control (FOC).
The FOC method was initially considered to be unsuitable for
low cost applications, owing to costly sensors and high power consumption.
However, improvements in the field have generated optimized opportunities for
inclusion in different types of power tools.
FOC Provides Unique Advantages
for Power Tool Designs
Compared to other
methods of commutation, FOC offers users with a number of exclusive advantages
such as superlative dynamic behavior, improved operational efficacy, complete
motor torque capabilities even at low speeds, decoupled flux and torque
control, four quadrant operations, and overload capabilities for short periods
of time.
The system offers optimal torque control through achieving
constant phase lag at 90 degrees to the stator, under different loads, while
simultaneously calculating rotor flux angles several times each second to
optimally modulate the current, in comparison to the limited commutation
options offered by conventional methods.
While FOC had many potential applications, it was largely
considered to be impractical owing to the lack of accuracy in simple power tool
devices to make use of the system in the right way. However, recently manufacturers
have claimed to have developed a sensor-less version to circumvent this issue.
InstaSPIN Eliminates
Complexities in Development of FOC Technologies
FOC systems are especially effective when used in power tools
that integrate centrifugal mechanisms, scientific instrumentation, or high
speed blowers or compressors, or those that are used in heat sensitive or portable
applications. However, the complexity of developing algorithms to meet the
requirements of every unique motor is a major challenge for designers.
InstaSPIN is a new FOC algorithm building tool by U.S. based
Texas Instruments that, simplifies this challenge significantly, by providing
ready to use blocks of algorithm functions that can be used by skilled
developers to easily optimize power tool motor performance over a wide variety
of operational conditions.
Torque/velocity control or position/velocity motion control
is performed through automated identification of the type of motor being used,
and the tuning of the torque controller without needing mechanical rotor
sensors.
FOC Finds Extensive
Use in Electric Drives in Power Tools
Field-oriented control (FOC) varies significantly from
ordinary control mechanisms for electric motors by enabling enhanced precision in
control capabilities on the basis of speed and torque. These aspects are highly
relevant for modern electric motors that are being used in the numerous power
tools and their applications.
Field of Control mechanisms can be utilized for durable,
very reliable and supremely energy-efficient designs for motors in various
power tool segments. Motors can be utilized at their optimal range of torque
and speed in any situation, while simultaneously offering users very accurate
and and fast regulation of motor speeds, which is very crucial for uses that
are commonly impacted by dynamic load changes, in devices such as ventilators
or pumps.
FOC also enables significant reductions in fluctuating torque,
which leads to a much smoother rotation of motor components. As a result
devices that make use of FOC emit lower levels of noise, which is especially
important for electrically powered power tools that normally do not have a loud
motor assembly. In addition, the smoother operations of such motors also noticeably
reduces the wear and tear of the devices bearings, resulting in greatly
enhanced robustness and reliability, enhancing the demand
in the power tools market.
The field-oriented control method has been viewed by device
designers as a very desirable combination to improve on performance features. However,
the system was considered too expensive for low cost applications. However, with
the introduction of Piccolo microcontrollers, and the internal InstaSPIN FOC
module, FOC is finding widespread application in power tools.
On the other hand, the usage of FOC in power tools also has
a number of disadvantages. The most impactful of these being the costs
associated with the implementation of rotor sensor components, which is implemented
either mechanically or in the form of a complex software, which so far have
been considered to be the most unreliable part of such power tools. The
unreliability of these components results in increasing costs or higher error
rates, which is why the InstaSPIN development is of such importance.
Searching for new
insights on the global power tools industry? For reliable and actionable
forecast information on the terms of location and product, visit Future Market Insights’ recent study on the global power tools
market. This report also talks about factors such as the competitive
environment, key market share holders, industry hierarchy, and popular
strategies.