JP2005328608A - Generating set - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a generating set which can let a short circuit current flow to a breaker quicker than a conventional one for activating the breaker in the case that a short-circuit accident occurs. <P>SOLUTION: This generating set supplies a load with the AC output power of a desired frequency of a self-excited inverter via an LC filter, a bus bar and a breaker, and is provided with a generator, a converter which converts the DC output power of the converter into the AC output power of a desired frequency, and a synchronous phase modifier between the LC filter and the bus bar. The synchronous phase modifier lets a short circuit current flow to the breaker to operate the breaker so as to be against a short circuit which has occurred on the load side by the breaker. Therefore, it can let a short-circuit current flow quicker than a conventional one to the breaker, thus it need not be equipped with a frequency converter which has an enough capacity to let a short-circuit current flow, and besides it can shorten an outage time at a short circuit accident. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a power generation apparatus that performs frequency conversion and supplies electric power of a desired frequency.

Conventional power generators supply AC power generated by an AC generator to the load. If the output frequency of the AC generator is different from the frequency required by the load, the load is converted to the desired frequency. Need to supply.
The conventional power generation apparatus described above is disclosed in, for example, Patent Document 1 and will be described with reference to the configuration diagram of FIG.

  In the figure, 1 is an AC generator, and the AC output power of this generator 1 is converted into a desired frequency by a frequency converter 2. The frequency converter 2 includes a converter 21, a self-excited inverter 22, and an LC filter 23. The converter 21 converts the received AC power into DC power and sends it to the self-excited inverter 22, which is self-excited. The inverter 22 converts DC power into AC power having a desired frequency. The LC filter 23 removes harmonic components contained in AC power having a desired frequency. Then, the AC power output from the frequency converter 2 goes to the bus 5 and is supplied to the respective loads 71, 72, 73 via the circuit breakers 41, 42, 43.

By the way, in such a power generator, when the short circuit 6 occurs between the circuit breaker 41 and the load 71, if left as it is, the voltage of the bus 5 remains lowered, and all the loads 71, 72, 73 are stopped. Therefore, it is desirable to immediately disconnect the short-circuit point. In order to cut off the short-circuit point, a short-circuit current sufficient for the circuit breaker 41 to react must flow. If a sufficient short-circuit current sufficient for the circuit breaker 41 to react is continuously supplied for the time set in the circuit breaker 41, the circuit breaker 41 is cut off, so that the short-circuit point is disconnected and the loads 72 and 73 You can return to driving.
JP 7-315293 A

  However, when a short-circuit accident occurs, the short-circuit current for operating the circuit breaker 41 must flow from the self-excited inverter 22, but due to the control delay of the self-excited inverter 22, until a sufficient short-circuit current flows from the occurrence of the short-circuit accident. Takes time.

  FIG. 4 is an image diagram showing temporal changes in the output voltage and the short circuit current until the circuit breaker 41 is operated by the short circuit current after the occurrence of the short circuit accident at the short circuit point. As can be seen from this figure, the short-circuit state continues until a short-circuit current is passed and the circuit breaker 41 is disconnected. If this power outage time is long, the operation cannot be continued depending on the load. Therefore, in order to shorten the power outage time, there is a problem that the short-circuit current must flow as fast as possible.

  Moreover, when letting a short circuit current flow from the frequency converter 2, it is necessary to make the frequency converter 2 into the capacity | capacitance which considered the short circuit current previously. The magnitude of this short-circuit current is significant in a marine power generation apparatus, and a magnitude of three times the rating is required. Therefore, the converter 21 and the self-excited inverter 22 having such a large capacity are required, and as a result, there is a problem that the size is increased and the cost is increased.

  The present invention has been made to solve the above-mentioned problems, and its problem is that when a short-circuit accident occurs, a short-circuit current is allowed to flow through the circuit breaker faster than before, and the capacity is sufficient to allow the short-circuit current to flow. Another object of the present invention is to provide a power generator capable of operating a circuit breaker without providing a frequency converter.

  In order to solve the above-mentioned problems, the invention described in claim 1 is a generator, a converter that converts the AC output power of the generator into DC power, and the DC output power of the converter into AC power of a desired frequency. In a self-excited inverter to be converted, and a power generator that supplies AC output power of a desired frequency of the self-excited inverter to a load via an LC filter, a bus, and a circuit breaker, synchronous adjustment is performed between the LC filter and the bus. A phase machine is provided, and the circuit breaker is operated by causing a short-circuit current to flow from the synchronous phase adjuster to the circuit breaker in response to a short circuit generated on the load side from the circuit breaker.

  According to the power generation device of the present invention, since the short-circuit current can be caused to flow through the circuit breaker faster than before by flowing the short-circuit current from the synchronous phase adjuster, the power failure time at the time of the short-circuit accident can be shortened. Further, since it is not necessary to provide a converter having a capacity sufficient to pass a short-circuit current and a self-excited inverter, the effect of reducing the size of the frequency conversion device and reducing the cost is achieved.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a configuration diagram of a power generator according to an embodiment of the present invention, and a configuration different from the conventional power generator is that a synchronous phase shifter 3 is connected between a frequency converter 2 and a bus 5. Since the other configuration is the same as that of the conventional example of FIG. 3 already described, the same portions are denoted by the same reference numerals and description thereof is omitted.

  In the figure, the synchronous phase adjuster 3 is always rotated to store rotational energy. For example, if a short circuit 6 occurs between the circuit breaker 41 and the load 71, the voltage of the bus 5 drops to near zero. At this time, the synchronous phase shifter 3 operates as a generator, instantaneously converts rotational energy into a short-circuit current, and continuously flows the short-circuit current for the time set in the circuit breaker 41 to operate the circuit breaker 41.

  FIG. 2 is an image diagram showing temporal changes in output voltage and short-circuit current after a short-circuit accident occurs between the circuit breaker 41 and the load 71 in the power generation apparatus of FIG. It is.

  As can be seen from this image diagram, when a short-circuit accident occurs, a short-circuit current instantaneously flows from the synchronous phase adjuster 3, so that the circuit breaker 41 can be operated faster by that amount compared to the conventional power generator. When the circuit breaker 41 is interrupted, the short circuit point is disconnected, and the loads 72 and 73 can return to normal operation.

  As described above, when the short-circuit accident occurs, the power generation device according to the present embodiment can be operated by causing the short-circuit current to flow through the circuit breaker 41 faster than before by flowing the short-circuit current from the synchronous phase adjuster 3. Therefore, the power failure time at the time of the short circuit accident of the loads 72 and 73 can be shortened. Further, there is an effect that the size of the frequency conversion device 2 is reduced and the cost is reduced.

The block diagram of one Embodiment of this invention. The image figure showing the time change of the output voltage at the time of the short circuit accident occurrence in FIG. 1, and a short circuit current. The block diagram of the conventional electric power generating apparatus. The image figure showing the time change of the output voltage at the time of the short circuit accident in FIG. 3, and a short circuit current.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Generator, 2 ... Frequency converter, 3 ... Synchronous phase adjuster, 5 ... Bus-bar, 6 ... Short-circuit point, 21 ... Converter, 22 ... Self-excited inverter, 23 ... LC filter, 41, 42, 43 ... Circuit breaker, 71, 72, 73 ... Load.

Claims (1)

A generator, a converter that converts the AC output power of the generator into DC power, a self-excited inverter that converts the DC output power of the converter into AC power of a desired frequency, and a desired frequency of the self-excited inverter In a power generator that supplies AC output power to a load via an LC filter, a bus, and a circuit breaker, a synchronous phase adjuster is provided between the LC filter and the bus, and a short circuit that occurs on the load side from the circuit breaker. Then, a short-circuit current flows from the synchronous phase adjuster to the circuit breaker to operate the circuit breaker.

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