Patent EP0085541A1 successfully refreshed from Google Patents.
EP0085541A1
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EP
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Synchronous motor drive apparatus
Assignee: Fanuc Corp
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Filing: 1983-01-27
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Granted: —
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Expires: 2003-01-27
Abstract
Abstract To reduce adverse effects due to the dead zone in a pulse-duration modulation circuit, the dead zone being provided for avoiding short-circuiting in an inverter circuit, the adverse effects including distortions of sinewave currents generated when low-frequency current commands are given, sound produced due to the excitation, and torque variations, a synchronous motor drive apparatus comprises a current detector circuit for detecting drive currents given to the synchronous motor, a difference output circuit for producing as outputs the differences iu, iv, iw between current commands given to the synchronous motor and the detected currents, a pulse-duration modulation circuit 114 for modulating signals indicative of the differences iu, iv, iw by way of pulse-duration modulation, an inverter circuit 115 for driving the synchronous motor, a voltage detector circuit 118 for detecting output voltages u, v, w from output terminals of the inverter circuit, and a circuit 120u, 120v, 120w for generating the differences between output voltages iu, iv, iw from the difference output circuit and the detected output voltages, whereby the synchronous motor can be driven by the outputs from the inverter circuit 115 which is operated by voltage command values indicating the last-mentioned differences.
Inventors
- 👤 Keiji Sakamoto
- 👤 Shinji Seki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 09:08
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/53; H02M7/537; H02M7/5387; H02M7/53871; H02M7/53875; H02P; H02P25/00; H02P25/02; H02P25/022; H02P25/03; H02M1/00; H02M1/38; H02M1/385
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
125 words
An apparatus for driving a synchronous motor, comprising: a current detector circuit for detecting drive currents given to the synchronous motor; a difference output circuit for producing as outputs the differences between current commands given to the synchronous motor and the detected currents; a pulse-duration modulation circuit for modulating signals indicative of said differences by way of pulse-duration modulation; an inverter circuit for driving the synchronous motor; and a voltage feedback loop for detecting output voltages from output terminals of said. inverter circuit and for generating the differences between output voltages from said difference output circuit and the detected output voltages, whereby the synchronous motor can be driven by the output from said inverter circuit;which is operated by voltage command values indicating said last-mentioned differences.
Claim 2
Independent Claim
125 words
An apparatus for driving a synchronous motor, comprising: a current detector circuit for detecting drive currents given to the synchronous motor; a difference output circuit for producing as outputs the differences between current commands given to the synchronous motor and the detected currents; a pulse-duration modulation circuit for modulating signals indicative of said differences by way of pulse-duration modulation; an inverter circuit for driving the synchronous motor; and a voltage feedback loop for detecting output voltages from output terminals of said. inverter circuit and for generating the differences between output voltages from said difference output circuit and the detected output voltages, whereby the synchronous motor can be driven by the output from said inverter circuit;which is operated by voltage command values indicating said last-mentioned differences.
Claim 3
Independent Claim
205 words
An apparatus for driving a synchronous motor, comprising: an inverter circuit for driving the synchronous mother; a current detector circuit for detecting drive currents given to the synchronous motor from the inverter circuit when the apparatus is in use; a difference output circuit for producing as outputs the differences between current commands given to the synchronous motor and the detected currents; a pulse-duration modulation circuit for modulating signals indicative of said differences by way of pulse-duration modulation and for driving the inverter in dependence upon the modulated signals, the pulse-duration modulation circuit being provided with a dead zone in order to introduce into the modulated signals a dead time in order to prevent a D.C. power supply for the inverter circuit from being short-circuited; and a voltage feedback loop for'detecting output voltages from output terminals of said inverter circuit and for generating the differences between output voltages from said difference output circuit and the detected output voltages, and for feeding these differences to the pulse-duration modulation circuit as said signals indicative of said differences between current commands and detected currents, thereby to introduce by means of said output voltages compensation effects to reduce adverse / caused by the dead zone of the pulse-duration modulation circuit.
Claim 4
Independent Claim
205 words
An apparatus for driving a synchronous motor, comprising: an inverter circuit for driving the synchronous mother; a current detector circuit for detecting drive currents given to the synchronous motor from the inverter circuit when the apparatus is in use; a difference output circuit for producing as outputs the differences between current commands given to the synchronous motor and the detected currents; a pulse-duration modulation circuit for modulating signals indicative of said differences by way of pulse-duration modulation and for driving the inverter in dependence upon the modulated signals, the pulse-duration modulation circuit being provided with a dead zone in order to introduce into the modulated signals a dead time in order to prevent a D.C. power supply for the inverter circuit from being short-circuited; and a voltage feedback loop for'detecting output voltages from output terminals of said inverter circuit and for generating the differences between output voltages from said difference output circuit and the detected output voltages, and for feeding these differences to the pulse-duration modulation circuit as said signals indicative of said differences between current commands and detected currents, thereby to introduce by means of said output voltages compensation effects to reduce adverse / caused by the dead zone of the pulse-duration modulation circuit.
Claim 5
Dependent Claim
60 words
An apparatus according to claim 1 or 2, wherein said voltage feedback loop comprises an interphase voltage detector circuit for detecting interphase voltages from phase output voltages from said inverter, a converter circuit for converting the interphase voltages into phase voltages, and arithmetic circuits for subtracting outputs issued by said converter circuit for current error signals in the respective phases.
Claim 6
Dependent Claim
47 words
An apparatus according to claim 3, wherein said interphase voltage detector circuit comprises interphase voltage detectors for detecting voltages between the phases and successive phases, and said converter circuit comprises phase voltage computing circuits for producing as outputs the phase voltages from the difference between interphase voltages.
Claim 7
Dependent Claim
29 words
An apparatus according to claim 4, wherein each of said interphase voltage detectors comprises an input, an output, and a photocoupler by which said input and output are interconnected.
Claim 8
Independent Claim
18 words
An apparatus according to any preceding claim wherein said apparatus in use, is driven by three-phase alternating currents.
References Cited (Backward Citations)
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