Patent US1769868A successfully refreshed from Google Patents.
EP0254073A2
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EP
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Harmonic suppressing device
Assignee: Mitsubishi Electric Corp
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Filing: 1987-06-26
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Granted: —
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Expires: 2007-06-26
Abstract
Abstract A harmonic suppressing device provided in a power system such as, for example, a transmission and distribution system or a power generating system, to filter higher harmonic currents generated by a higher harmonic current source of the power system such as, for example, a cycloconverter. The harmonic suppressing device comprises, as the principal components thereof, a passive filter serving as a high-order higher harmonic filtering unit for filtering higher harmonic currents of comparatively high orders among those generated by the higher harmonic current source, and an active filter serving as low-order higher harmonic filtering unit for filtering higher harmonic currents of comparatively low orders among those generated by the higher harmonic current source. The active filter comprises: a main active filtering circuit comprising a plurality of switching transistors, rectifying diodes combined with the switching transistors, respectively, a capacitor, and a reactor; an operating circuit which calculates controlling data for controlling the commutating action of the main active filtering circuit on the basis of the detected values of the higher harmonic currents that flows into the power source side of the power system and the detected values of the output voltage of the higher harmonic current source; and a control circuit which gives control signals such as, for example, pulse width modulating signals to the main active filtering circuit. The harmonic suppressing device is capable of filtering higher harmonic currents in a wide frequency band.
Inventors
- 👤 Masatoshi Mitsubishi Denki K.K. Takeda
- 👤 Kazuo Mitsubishi Denki K.K. Ikeda
- 👤 Yoshiharu Mitsubishi Denki K.K. Tominaga
- 👤 Kenji Mitsubishi Denki K.K. Mori
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 21:37
CPC Classifications
H; H02; H02J; H02J3/00; H02J3/01; H02M; H02M1/00; H02M1/08; H02M1/084; H02M1/12; H02M1/42; H02M1/4208; H02M1/4283; Y; Y02; Y02B; Y02B70/00; Y02B70/10; Y02E; Y02E40/00; Y02E40/40
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
81 words
A harmonic suppressing device for use in a power system having a higher harmonic current source as a load which generates higher harmonic currents of variable frequencies varying in a wide frequency band, which comprises: a high-order higher harmonic filtering unit for filtering high-order higher harmonic currents in a predetermined frequency band including a tuned frequency band; and a low-order higher harmonic filtering unit for filtering low-order higher harmonic currents in a fixed frequency band other than the tuned frequency band.
Claim 2
Dependent Claim
81 words
A harmonic suppressing device for use in a power system having a higher harmonic current source as a load which generates higher harmonic currents of variable frequencies varying in a wide frequency band, which comprises: a high-order higher harmonic filtering unit for filtering high-order higher harmonic currents in a predetermined frequency band including a tuned frequency band; and a low-order higher harmonic filtering unit for filtering low-order higher harmonic currents in a fixed frequency band other than the tuned frequency band.
Claim 3
Dependent Claim
44 words
A harmonic suppressing device as recited in Claim l, wherein said high-order higher harmonic filtering unit is a passive filter comprising a series connection of a capacitor and a reactor, and connected in parallel to said power system and said higher harmonic current source.
Claim 4
Dependent Claim
65 words
A harmonic suppressing device as recited in Claim l, wherein said low-order higher harmonic filtering unit is an active filter having a pulse width modulating (PWM) control circuit, and capable of detecting the higher harmonic components of a current which flows into the alternating current source side of said power system and filtering low-order higher harmonic currents on the basis of the result of detection.
Claim 5
Dependent Claim
53 words
A harmonic suppressing device as recited in Claim l, wherein said higher harmonic current source is a cycloconverter serving as a power converter, and said high-order higher harmonic filtering unit and said low-order higher harmonic filtering unit are capable of filtering higher harmonic currents in a wide frequency band generated by said cycloconverter.
Claim 6
Dependent Claim
151 words
A harmonic suppressing device comprising: a passive filter comprising a series connection of a capacitor and a reactor, and serving as a high-order higher harmonic filtering unit for filtering higher harmonic currents of comparatively high orders in a frequency band around a tuned point among higher harmonic currents generated by the higher harmonic current source of a power system; and an active filter serving as a low-order higher harmonic filtering unit for filtering higher harmonic currents of comparatively low orders in a frequency band around an antiresonance point among those generated by said higher harmonic current source, connected in parallel to said passive filter and adapted so as to be controlled on the basis of a value obtained by multiplying the detected value of a higher harmonic current that flows into the power source side beyond the connecting point of said passive filter and a power source by a fixed gain.
Claim 7
Dependent Claim
151 words
A harmonic suppressing device comprising: a passive filter comprising a series connection of a capacitor and a reactor, and serving as a high-order higher harmonic filtering unit for filtering higher harmonic currents of comparatively high orders in a frequency band around a tuned point among higher harmonic currents generated by the higher harmonic current source of a power system; and an active filter serving as a low-order higher harmonic filtering unit for filtering higher harmonic currents of comparatively low orders in a frequency band around an antiresonance point among those generated by said higher harmonic current source, connected in parallel to said passive filter and adapted so as to be controlled on the basis of a value obtained by multiplying the detected value of a higher harmonic current that flows into the power source side beyond the connecting point of said passive filter and a power source by a fixed gain.
Claim 8
Dependent Claim
52 words
A harmonic suppressing device as recited in Claim 5, wherein said active filter comprises: a main active filtering circuit comprising a parallel connection of a plurality of switching transistors, diodes connected in parallel to said switching transistors, respectively, and a capacitor; and control means for controlling said switching transistors for on-off operation.
Claim 9
Dependent Claim
115 words
A harmonic suppressing device as recited in Claim 6, wherein said control means is a PWM control circuit capable of carrying out PWM control on the basis of a value obtained by processing through subtraction, amplification and addition the output of a gain circuit which executes a first order lag operation by multiplying the detected values of higher harmonic currents that flow into the power source side of said power system by a fixed gain, detected current values of the output currents of said main active filtering circuit, and the detected voltage values of higher harmonic currents generated by said higher harmonic current source and flowing into the power source side of said power system.
Claim 10
Dependent Claim
47 words
A harmonic suppressing device as recited in Claim 5, wherein said passive filter is a high-order higher harmonic filtering unit constituted so as to filter higher harmonic currents of comparatively high orders in the range of order of the eleventh to the thirteenth about the resonance point.
Claim 11
Dependent Claim
46 words
A harmonic suppressing device as recited in Claim 5, wherein said active filter is a low-order higher harmonic filtering unit constituted so as to filter higher harmonic currents of comparatively low orders in the range of order of the fifth to the seventh about antiresonance point.
Claim 12
Dependent Claim
217 words
l0. A harmonic suppressing device comprising: a passive filter serving as a high-order higher harmonic filtering unit comprising a series connection of a capacitor and a reactor, and capable of filtering higher harmonic currents of comparatively high orders in a frequency band around a tuned point among those generated by a higher harmonic current source; and an active filter serving as a low-order higher harmonic filtering unit for filtering higher harmonic currents of comparatively low orders in a frequency band around an antiresonance point, comprising: a main active filtering circuit comprising a parallel connection of a plurality of switching transistors, diodes connected in parallel to said switching transistors, respectively, and a capacitor; and control means comprising: operating means which processes through a predetermined phase advancing operation the detected values of higher harmonic currents that flows into the power source side of said power system beyond the connecting point of said passive filter and said power system; and control means for controlling said switching transistors for on-off operation by a control output obtained by subjecting the detected current values of the output currents of said main circuit, and detected voltage values detected in the neighborhood of said higher harmonic current source on the basis of the results of operation of said operating means to addition, subtraction and amplification.
Claim 13
Dependent Claim
217 words
l0. A harmonic suppressing device comprising: a passive filter serving as a high-order higher harmonic filtering unit comprising a series connection of a capacitor and a reactor, and capable of filtering higher harmonic currents of comparatively high orders in a frequency band around a tuned point among those generated by a higher harmonic current source; and an active filter serving as a low-order higher harmonic filtering unit for filtering higher harmonic currents of comparatively low orders in a frequency band around an antiresonance point, comprising: a main active filtering circuit comprising a parallel connection of a plurality of switching transistors, diodes connected in parallel to said switching transistors, respectively, and a capacitor; and control means comprising: operating means which processes through a predetermined phase advancing operation the detected values of higher harmonic currents that flows into the power source side of said power system beyond the connecting point of said passive filter and said power system; and control means for controlling said switching transistors for on-off operation by a control output obtained by subjecting the detected current values of the output currents of said main circuit, and detected voltage values detected in the neighborhood of said higher harmonic current source on the basis of the results of operation of said operating means to addition, subtraction and amplification.
Claim 14
Dependent Claim
72 words
A harmonic suppressing device as recited in Claim l0, wherein said control means for controlling said main active filtering circuit is a PWM control circuit of a pulse width modulating system for controlling said main active filtering circuit for on-off operation, and said operating means is a differential operating circuit which processes the detected current values of the higher harmonic currents that flow into the power source side through phase advancing operation.
Claim 15
Dependent Claim
56 words
A harmonic suppressing device as recited in Claim l0, wherein said passive filter serving as a high-order higher harmonic filtering unit filters high-order harmonic currents of orders of the llth to l3th, and said active filter serving as a low-order higher harmonic filtering unit filters low-order higher harmonic currents of orders of the 5th to 7th.
Claim 16
Dependent Claim
41 words
A harmonic suppressing device as recited in Claim l0, wherein said passive filter filters high-order higher harmonic currents of orders of the 23rd to 25th, and said active filter filters low-order higher harmonic currents of orders of the 5th to 7th.
Claim 17
Dependent Claim
34 words
A harmonic suppressing device as recited in Claim l0, wherein said higher harmonic current source of said power system is a cycloconverter including a semiconductor device for converting the power of said power system.
Claim 18
Dependent Claim
50 words
A harmonic suppressing device as recited in Claim l0, wherein said passive filter and said active filter are provided in a three-phase alternating current circuit comprising a three-phase alternating current power source, and a cycloconverter for converting the frequency of the power supplied from said three-phase alternating current power source.
Claim 19
Dependent Claim
184 words
A harmonic suppressing device provided with a passive filter serving as a high-order higher harmonic filtering unit for filtering higher harmonics of comparatively high orders around a tuning point among higher harmonics in a power system, which comprises an active filter serving as a low-order higher harmonic filtering unit, comprising: a current controller which detects a current including higher harmonics (higher harmonic current) which flows into the side of the power source of the power system at a position near the power source, and calculates a compensating current for filtering higher harmonics of comparatively low orders (low-order higher harmonics) around an antiresonance point among the higher harmonics; and a voltage type inverter which controls the compensating current for compensating the system current by controlling a power semiconductor switching element for on-off operation on the basis of a control signal provided by the pulse width modulation control (PWM) operation of said current controller, namely, a control operation for modulating the pulse width of a reference voltage obtained from the difference between a higher harmonic current to be compensated and an actual output higher harmonic current.
Claim 20
Dependent Claim
184 words
A harmonic suppressing device provided with a passive filter serving as a high-order higher harmonic filtering unit for filtering higher harmonics of comparatively high orders around a tuning point among higher harmonics in a power system, which comprises an active filter serving as a low-order higher harmonic filtering unit, comprising: a current controller which detects a current including higher harmonics (higher harmonic current) which flows into the side of the power source of the power system at a position near the power source, and calculates a compensating current for filtering higher harmonics of comparatively low orders (low-order higher harmonics) around an antiresonance point among the higher harmonics; and a voltage type inverter which controls the compensating current for compensating the system current by controlling a power semiconductor switching element for on-off operation on the basis of a control signal provided by the pulse width modulation control (PWM) operation of said current controller, namely, a control operation for modulating the pulse width of a reference voltage obtained from the difference between a higher harmonic current to be compensated and an actual output higher harmonic current.
Claim 21
Dependent Claim
180 words
A harmonic suppressing device provided with a passive filter serving as a high-order higher harmonic filtering unit for filtering higher harmonics of comparatively high orders around a tuning point among higher harmonics in a power system, which comprises an active filter serving as a low-order higher harmonic filtering unit, comprising: a current controller which detects a current including higher harmonics which flows into the side of the power source of the power system (higher harmonic current) from a cycloconverter, namely, a higher harmonic generating source, at a position near the higher harmonic generating source, and calculates a compensating current for filtering higher harmonics of comparatively low orders around an antiresonance point; and a current type inverter which controls a power semiconductor switching element for on-off operation to control the compensating current for the system current on the basis of an on-off signal provided by the constant-current control operation of said current controller, namely, the calculation of the difference between the detected actual current and a command current and the discrimination of the polarity of the difference by a hysteresis comparator.
Claim 22
Dependent Claim
180 words
A harmonic suppressing device provided with a passive filter serving as a high-order higher harmonic filtering unit for filtering higher harmonics of comparatively high orders around a tuning point among higher harmonics in a power system, which comprises an active filter serving as a low-order higher harmonic filtering unit, comprising: a current controller which detects a current including higher harmonics which flows into the side of the power source of the power system (higher harmonic current) from a cycloconverter, namely, a higher harmonic generating source, at a position near the higher harmonic generating source, and calculates a compensating current for filtering higher harmonics of comparatively low orders around an antiresonance point; and a current type inverter which controls a power semiconductor switching element for on-off operation to control the compensating current for the system current on the basis of an on-off signal provided by the constant-current control operation of said current controller, namely, the calculation of the difference between the detected actual current and a command current and the discrimination of the polarity of the difference by a hysteresis comparator.
Claim 23
Dependent Claim
176 words
A harmonic suppressing device provided with a passive filter serving as a high-order higher harmonic filtering unit for filtering higher harmonics of comparatively high orders around a tuning point among higher harmonics in a power system, which comprises an active filter serving as a low-order higher harmonic filtering unit, comprising: a current controller which detects a current including higher harmonics (higher harmonic current) which flows into the side of the power source of the power system at a position near the power source, and calculates a compensating current for filtering higher harmonics of comparatively low orders (low-order higher harmonics) around an antiresonance point among the higher harmonics; and a current type inverter which controls a power semiconductor switching element for on-off operation to control the compensating current for the system current on the basis of an on-off signal provided by the constant-current control operation of said current controller, namely, the calculation of the difference between the detected actual current and a command current and the discrimination of the polarity of the difference by a hysteresis comparator.
Claim 24
Dependent Claim
176 words
A harmonic suppressing device provided with a passive filter serving as a high-order higher harmonic filtering unit for filtering higher harmonics of comparatively high orders around a tuning point among higher harmonics in a power system, which comprises an active filter serving as a low-order higher harmonic filtering unit, comprising: a current controller which detects a current including higher harmonics (higher harmonic current) which flows into the side of the power source of the power system at a position near the power source, and calculates a compensating current for filtering higher harmonics of comparatively low orders (low-order higher harmonics) around an antiresonance point among the higher harmonics; and a current type inverter which controls a power semiconductor switching element for on-off operation to control the compensating current for the system current on the basis of an on-off signal provided by the constant-current control operation of said current controller, namely, the calculation of the difference between the detected actual current and a command current and the discrimination of the polarity of the difference by a hysteresis comparator.
Claim 25
Dependent Claim
188 words
A harmonic suppressing device provided with a passive filter serving as a high-order higher harmonic filtering unit for filtering higher harmonics of comparatively high orders around a tuning point among higher harmonics in a power system, which comprises an active filter serving as a low-order higher harmonic filtering unit, comprising: a current controller which detects a current including higher harmonics which flows into the side of the power source of the power system (higher harmonic current) from a cycloconverter, namely, a higher harmonic generating source, at a position near the higher harmonic generating source, and calculates a compensating current for filtering higher harmonics of comparatively low orders around an antiresonance point; and a voltage type inverter which controls the compensating current for compensating the system current by controlling a power semiconductor switching element for on-off operation on the basis of a control signal provided by the pulse width modulation control (PWM) operation of said current controller, namely, a control operation for modulating the pulse width of a reference voltage obtained from the difference between a higher harmonic current to be compensated and an actual output higher harmonic current.
Claim 26
Dependent Claim
188 words
A harmonic suppressing device provided with a passive filter serving as a high-order higher harmonic filtering unit for filtering higher harmonics of comparatively high orders around a tuning point among higher harmonics in a power system, which comprises an active filter serving as a low-order higher harmonic filtering unit, comprising: a current controller which detects a current including higher harmonics which flows into the side of the power source of the power system (higher harmonic current) from a cycloconverter, namely, a higher harmonic generating source, at a position near the higher harmonic generating source, and calculates a compensating current for filtering higher harmonics of comparatively low orders around an antiresonance point; and a voltage type inverter which controls the compensating current for compensating the system current by controlling a power semiconductor switching element for on-off operation on the basis of a control signal provided by the pulse width modulation control (PWM) operation of said current controller, namely, a control operation for modulating the pulse width of a reference voltage obtained from the difference between a higher harmonic current to be compensated and an actual output higher harmonic current.
References Cited (Backward Citations)
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