1. An inverter device for driving an electric motor, comprising:
a PWM-waveform generation section which generates a waveform for performing PWM control on the electric motor;
a rotational-speed detection section which detects a rotational speed of the electric motor;
a carrier-frequency calculation section which calculates a carrier frequency on the basis of the rotational speed detected by the rotational-speed detection section; and
a carrier-frequency switching section which switches the carrier frequency of the waveform generated by the PWM-waveform generation section, on the basis of the calculated carrier frequency,
wherein the carrier-frequency calculation section calculates, as the carrier frequency, a frequency which is increased with an increase in the electric-motor rotational speed detected by the rotational-speed detection section, and
wherein the carrier-frequency calculation section calculates a fundamental carrier frequency on the basis of the electric-motor rotational speed and calculates a carrier frequency to be actually used by multiplying the fundamental carrier frequency by a gain depending on at least one of an output torque from the electric motor and a load inertia.
2. A slewing construction machine comprising:
a lower traveling body;
an upper slewing body mounted on the lower traveling body so as to be slewable;
a slewing electric motor which slews the upper slewing body; and
the inverter device according to claim 1, which is used to drive the slewing electric motor.
3. A slewing construction machine comprising: a lower traveling body; an upper slewing body mounted on the lower traveling body so as to be slewable; a slewing electric motor which slews the upper slewing body; and the inverter device according to claim 1, which is used to drive the slewing electric motor; and a rotational-angular-acceleration calculation section which calculates a rotational angular acceleration of the electric motor and a carrier-frequency switching limitation section which stops frequency switching performed by the carrier-frequency switching section when the rotational angular acceleration calculated by the rotational angular-acceleration calculation section exceeds a set value.
4. A slewing construction machine comprising: a lower traveling body; an upper slewing body mounted on the lower traveling body so as to be slewable; a slewing electric motor which slews the upper slewing body; and the inverter device according to claim 1, which is used to drive the slewing electric motor wherein the carrier-frequency calculation section switches the carrier frequency more finely in a high-frequency output region that involves a higher output frequency than in the other regions in the relationship between the electric-motor rotational speed and an inverter output.
5. A slewing construction machine comprising: a lower traveling body, an upper slewing body mounted on the lower traveling body so as to be slewable; a slewing electric motor which slews the upper slewing body; and the inverter device according to claim 1, which is used to drive the slewing electric motor wherein the carrier-frequency switching section switches the carrier frequency in a step-by-step manner for each of a plurality of zones obtained by dividing an entire region of the electric-motor rotational speed in advance.
6. The slew construction machine according to claim 5, wherein hysteresis is applied to the step-by-step switching of the carrier frequency performed by the carrier-frequency switching section.
7. An inverter device for driving an electric motor, comprising:
a PWM-waveform generation section which generates a waveform for performing PWM control on the electric motor;
a rotational-speed detection section which detects a rotational speed of the electric motor;
a carrier-frequency calculation section which calculates a carrier frequency on the basis of the rotational speed detected by the rotational-speed detection section;
a carrier-frequency switching section which switches the carrier frequency of the waveform generated by the PWM-waveform generation section, on the basis of the calculated carrier frequency; and
a rotational-angular-acceleration calculation section which calculates a rotational angular acceleration of the electric motor and a carrier-frequency switching limitation section which stops frequency switching performed by the carrier-frequency switching section when the rotational angular acceleration calculated by the rotational angular-acceleration calculation section exceeds a set value,
wherein the carrier-frequency calculation section calculates, as the carrier frequency, a frequency which is increased with an increase in the electric-motor rotational speed detected by the rotational-speed detection section.
8. An inverter device for driving an electric motor, comprising:
a PWM-waveform generation section which generates a waveform for performing PWM control on the electric motor;
a rotational-speed detection section which detects a rotational speed of the electric motor;
a carrier-frequency calculation section which calculates a carrier frequency on the basis of the rotational speed detected by the rotational-speed detection section; and
a carrier-frequency switching section which switches the carrier frequency of the waveform generated by the PWM-waveform generation section, on the basis of the calculated carrier frequency,
wherein the carrier-frequency calculation section calculates, as the carrier frequency, a frequency which is increased with an increase in the electric-motor rotational speed detected by the rotational-speed detection section, and
wherein the carrier-frequency calculation section switches the carrier frequency more finely in a high-frequency output region that involves a higher output frequency than in the other regions in the relationship between the electric-motor rotational speed and an inverter output.
9. An inverter device for driving an electric motor, comprising:
a PWM-waveform generation section which generates a waveform for performing PWM control on the electric motor;
a rotational-speed detection section which detects a rotational speed of the electric motor;
a carrier-frequency calculation section which calculates a carrier frequency on the basis of the rotational speed detected by the rotational-speed detection section; and
a carrier-frequency switching section which switches the carrier frequency of the waveform generated by the PWM-waveform generation section, on the basis of the calculated carrier frequency,
wherein the carrier-frequency calculation section calculates, as the carrier frequency, a frequency which is increased with an increase in the electric-motor rotational speed detected by the rotational-speed detection section, and
wherein the carrier-frequency switching section switches the carrier frequency in a step-by-step manner for each of a plurality of zones obtained by dividing an entire region of the electric-motor rotational speed in advance.
10. The inverter device according to claim 9, wherein hysteresis is applied to the step-by-step switching of the carrier frequency performed by the carrier-frequency switching section.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An illumination system providing monochromatic light output, said illumination system comprising:
at least one illumination source, said a least one illumination source providing white light; and
a monochromatic filter, disposed between said at least one illumination source and an object to be illuminated, for converting said white light to monochromatic light of a predetermined color andor wavelength.
2. The illumination system of claim 1, wherein said at least one illumination source is a white LED array.
3. The illumination system of claim 1, wherein said at least one illumination source is selected from the group of lighting consisting of a ring light, a DOAL, an SCDI, a CDI.
4. Illumination system of claim 1, wherein said illumination sources mounted in a housing and wherein said housing includes a light diffuser or clear window disposed between said at least one illumination source and said object to be illuminated, and wherein said monochromatic filter is disposed between said illumination source and said light diffuser or clear window.