Hitachi L100 Function waveform can be expressed as a the summation of a, System. See also choke

A–4

Glossary

Appendix A

Frequency Setting	While frequency has a broad meaning in electronics, it typically
	refers to motor speed for variable-frequency drives (inverters). This
	is because the output frequency of the inverter is variable, and is
	proportional to the attained motor speed. For example, a motor with
	a base frequency of 60 Hz can be speed controlled with an inverter
	output varying form 0 to 60 Hz. See also base frequency, carrier
	frequency, and slip.
Harmonics	According to Fourier Series mathematics, a periodic (repeating)
	function (waveform) can be expressed as a the summation of a
	series of pure sine waves of related frequencies. The lowest
	frequency is the fundamental, while all the other wave components
	are called harmonics. The square waves used in inverters produce
	high-frequency harmonics, even though the main goal is to produce
	lower-frequency sine waves. These harmonics can be harmful to
	electronics (including motor windings) and cause radiated energy
	that interferes with nearby electronic devices. A choke is sometimes
	used to suppress the transmission of harmonics in an electrical
	system. See also choke.
Horsepower	A unit of physical measure to quantify the amount of work done per
	unit of time. You can directly convert between horsepower and
	Watts as measurements of power.
IGBT	Insulated Gate Bipolar Transistor (IGBT) - a semiconductor
	transistor capable of conducting very large currents when in satura-
	tion and capable of withstanding very high voltages when it is off.
	This high-power bipolar transistor is the type used in Hitachi invert-
	ers.
Inertia	The natural resistance a stationary object to being moved by an
	external force. See also momentum.
Intelligent Terminal	A configurable input or output logic function on the Hitachi invert-
	ers. Each terminal may be assigned one of several functions.
Inverter	A device that electronically changes DC to AC current through a
	alternating process of switching the input to the output, inverted and
	non-inverted. A variable speed drive such as the Hitachi L100 is
	also called an inverter, since it contains three inverter circuits to
	generate 3-phase output to the motor.
Isolation Transformer	A transformer with 1:1 voltage ratio that provides electrical isola-
	tion between its primary and secondary windings. These are
	typically used on the power input side of the device to be protected.
	An isolation transformer can protect equipment from a ground fault
	or other malfunction of nearby equipment, as well as attenuate
	harmful harmonics and transients on the input power.
Jogging Operation	Usually done manually, a jog command from an operator’s panel
	requests the motor/drive system to run indefinitely in a particular
	direction, until the machine operator ends the jog operation.