EP0432269A1
Expired / Lapsed
EP
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System separation detector for power source of distributed type
Assignee: Shikoku Research Institute Inc
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Filing: 1990-04-05
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Granted: —
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Expires: 2010-04-05
Abstract
Abstract In a power source (100) of a distributed type having a generating element (1) and an inverter (2) that converts the output of the generating element (1) into AC output, given information is superposed by a system separation detector (40) on the AC output of the inverter (2). An effective-power detecting means (12) provided on the AC output side of the inverter (2) outputs a signal including the given information. From this signal, the system separation detector (40) extracts the information, detecting the opening of a breaker (7) in a power system (6) connected to the output side of the inverter (2), thus detecting the system separation. Unlike the prior art, therefore, there is no need of installing a special signal line between the power source (100) of the distributed type and the power system (6) to transmit the information of the opening of the circuit breaker (7) in the power system (6).
Inventors
- 👤 Hiromasa Higasa
- 👤 Fumihiko Ishikawa
- 👤 Shigenori 12-26 Kamino-Cho 2-Chome Matsumura
- 👤 Takeshi Fuji Electric Co. Ltd. Takemura
- 👤 Toshihisa Fuji Electric Co. Ltd. Shimizu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 05:01
CPC Classifications
H; H02; H02J; H02J3/00; H02J3/38; H02J9/00; H02J9/04; H02J9/06; H02J9/062
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
79 words
A system disconnection detection circuit for a distributed location power source having a generating element, and an inverter for converting a generated output from said generating element into an AC output, said system characterized by comprising: superimposing means for superimposing prescribed information on the inverter AC output; and detection means for detecting system disconnection on the output side of the inverter on the basis of the AC output of the inverter on which the prescribed information has been superimposed.
Claim 2
Dependent Claim
97 words
A system disconnection detection circuit for a distributed location power source as claimed in claim 1, characterized in that said detection means comprises; opening control means for opening a circuit breaker on the AC power output side of the inverter in response to the system disconnection detection; and close control means for detecting, after opening of the circuit breaker, the restoration of power in a power system side to which the circuit breaker is connected on the basis of the voltage of the power system side, and for closing the circuit breaker in response to the detection.
Claim 3
Dependent Claim
200 words
A system disconnection detection circuit for a distributed location power source as claimed in claim 1, characterized in that said superimposing means comprises: first oscillating means for oscillating at a frequency proportional to or substantially proportional to the generated output power from said generating element; and effective power setting means for increasing or decreasing an AC output effective power command to be fed to the inverter at a substantially fixed ratio to the command in synchronism with the oscillating period of the first oscillating means, the command corresponding to the generated output power from the generating element; and wherein said detector means comprises: second oscillator means for producing a pulse train signal of a frequency proportional to or substantially proportional to the value of the AC output effective power, or the increase or decrease value of the effective power; a counter for upcounting and downcounting the number of pulses in the pulse train signal from the second oscillating means in synchronism with the oscillating period of the first oscillating means; and means for detecting a system disconnection on the AC output side of the inverter on the basis of the resultant value of the upcount and downcount of the counter.
Claim 4
Dependent Claim
97 words
A system disconnection detection circuit for a distributed location power source as claimed in claim 3, characterized in that said detection means comprises: opening control means for opening a circuit breaker on the AC power output side of the inverter in response to the system disconnection detection; and close control means for detecting, after opening of the circuit breaker, the restoration of power in a power system side to which the circuit breaker is connected on the basis of the voltage of the power system side, and for closing the circuit breaker in response to the detection.
Claim 5
Dependent Claim
138 words
A system disconnection detection circuit for a distributed location power source as claimed in claim 1, characterized in that said superimposing means comprises: oscillating means for oscillating at a specific frequency; and effective power setting means for increasing or decreasing an AC output effective power command to be fed to the inverter at a substantially fixed ratio to the command in synchronism with the oscillating period of the oscillating means, the command corresponding to the generated output power from the generating element; and wherein said detector means comprises: frequency component extraction means for extracting an oscillation frequency component of the oscillating means from the inverter output; and means for detecting a system disconnection on the output side of the inverter on the basis of an amount of the oscillation frequency component produced from the frequency component extraction means.
Claim 6
Dependent Claim
97 words
A system disconnection detection circuit for a distributed location power source as claimed in claim 5, characterized in that said detector means comprises: opening control means for opening a circuit breaker on the AC power output side of the inverter in response to the system disconnection detection; and close control means for detecting, after opening of the circuit breaker, the restoration of power in a power system side to which the circuit breaker is connected on the basis of the voltage of the power system side, and for closing the circuit breaker in response to the detection.
Claim 7
Dependent Claim
72 words
A system disconnection detection circuit for a distributed location power source as claimed in claim 5, characterized in that said oscillating means changes the oscillation frequency in response to a generated output signal from a generating means that periodically produces a signal having a prescribed voltage change pattern, and said frequency component extraction means changes an extraction frequency in tune with a frequency of the oscillating output signal from the oscillating means.
Claim 8
Dependent Claim
97 words
A system disconnection detection circuit for a distributed location power source as claimed in claim 7, characterized in that said detection means comprises: opening control means for opening a circuit breaker on the AC power output side of the inverter in response to the system disconnection detection; and close control means for detecting, after opening of the circuit breaker, the restoration of power in a power system side to which the circuit breaker is connected on the basis of the voltage of the power system side, and for closing the circuit breaker in response to the detection.
Claim 9
Dependent Claim
187 words
A system disconnection detection circuit for a distributed location power source as claimed in claim 1, characterized in that said superimposing means comprises: sinusoidal wave signal output means for outputting an output voltage waveform command in the inverter; first oscillator means; second oscillator means that cyclically changes an oscillation frequency of the first oscillating means; and means to forming an addition signal for controlling elements in the inverter that convert DC to AC, the addition signal being formed by adding the output voltage wave command signal from the sinusoidal wave signal output means to an oscillating output signal from the first oscillating means; and wherein said detector means comprises: frequency component extraction means for extracting an oscillation frequency component of the first oscillating means from the inverter output; a counter for counting the number of times at which the amplitude of the signal outputted from the frequency component extraction means exceeds a prescribed value during one oscillation period of the second oscillating means; and means for detecting a system disconnection on the output side of the inverter on the basis of the count value from the counter.
Claim 10
Dependent Claim
97 words
A system disconnection detection circuit for a distributed location power source as claimed in claim 9, characterized in that said detection means comprises: opening control means for opening a circuit breaker on the AC power output side of the inverter in response to the system disconnection detection; and close control means for detecting, after opening of the circuit breaker, the restoration of power in a power system side to which the circuit breaker is connected on the basis of the voltage of the power system side, and for closing the circuit breaker in response to the detection.
References Cited (Backward Citations)
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