JP2000125598A - Method for confirming disconnection of output power of ac generator from another power source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which the disconnection of a generator power source from another power source can be confirmed by measuring the difference between the phases at both ends of a circuit breaker. SOLUTION: A circuit is constituted in such a way that a generator power source 1 and another power source 2 are connected to both ends of a circuit breaker 3 and a synchronization point detecting device 4 is connected in parallel with the breaker 3, and then, the voltage phases at both ends of the breaker 3 are necessarily made coincident with each other so that not phase difference may by caused between the phases. When the power source 1 is disconnected from the power source 2 by opening the breaker 3, the frequency of the power source 1 changes due to a drooping characteristic, because a load 5 connected to the power source 1 is also disconnected. On the other hand, the detecting device 4 compares two kinds of power supply voltages with each other and, while both power sources 1 and 2 are linked, always outputs a signal, because no difference exists between the voltage phases. When the power sources 1 and 2 are disconnected from each other and a difference is produced between the voltage phases, the device 4 does not output any signal. Therefore, the disconnection of the power source 1 from the power source 2 can be confirmed surely and easily with an inexpensive device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit in which an output power supply of an alternator (hereinafter referred to as a generator power supply) is interconnected with another power supply through a circuit breaker. And a confirmation method for confirming disconnection of another power supply.

[0002]

2. Description of the Related Art Conventionally, in order to confirm disconnection of an output power supply of an AC generator from another power supply, a circuit breaker having an auxiliary contact which operates in conjunction with a main contact is used. It is common to confirm that the power supply has been disconnected from the other power supply by operating the auxiliary contact of the circuit breaker.

[0003]

However, in such a checking method, it is not checked whether the main contacts of the circuit breaker actually operate and both power supplies are disconnected. Therefore, when an abnormality occurs in the auxiliary or main contact of the circuit breaker and the two contacts are not linked, there is a problem that the generator power supply and the other power supply are erroneously recognized as being disconnected. The present invention has been made in view of the above points, and has as its object to solve these problems and to confirm that the generator power supply and other power supplies have been disconnected from each other. And other power supply disconnection confirmation methods.

[0004]

Means for achieving the object are as follows: 1) The power supply of an AC generator having a drooping characteristic and a circuit breaker for interconnecting another power supply according to claim 1; It is a method of confirming the disconnection, wherein when the rotation speed of the generator changes due to the drooping characteristic and a difference occurs between the two voltage phases detected at both ends of the circuit breaker, the output power of the AC generator is A method for confirming the disconnection between an output power supply of an AC generator and another power supply, characterized in that it is recognized that the power supply has been disconnected from another power supply by a circuit breaker.

[0005] 2) A method for confirming disconnection of an output power supply of an AC generator having no drooping characteristic and a circuit breaker for interconnecting another power supply according to claim 2, wherein the rotation speed of the generator is increased. Or the rotation speed of the generator changes due to the lowering command,
When there is a difference between the two voltage phases detected at both ends of the circuit breaker, it is recognized that the output power supply of the AC generator is disconnected from the other power supply by the circuit breaker. This is a method for confirming the disconnection of the output power of the machine from other power supplies. Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0006]

FIG. 1 is an explanatory view showing one embodiment of the present invention. In FIG. 1, a generator power supply 1 and another power supply 2 are shown.
Are connected to both ends of the circuit breaker 3, and a synchronization point detecting device 4 is connected in parallel with the circuit breaker 3. And breaker 3
Is in the closed state, the voltage phases at both ends always match, so that no difference is generated in the phases. In such a configuration, in the case of claim 1, the circuit breaker 3 is released and the generator power supply 1
Is disconnected from the other power supply 2, the load 5 connected to the generator power supply 1 is also disconnected, so that the frequency of the generator power supply 1 changes due to the drooping characteristic.

In the case of claim 2, when a command to increase or decrease the number of revolutions is given from the outside to the generator at the same time as the command to release the circuit breaker 3, the circuit breaker 3 is released and the generator power supply 1 is connected to the other power supply 2 If it is further separated, the frequency of the generator power supply 1 changes. If such a checking method is used, the generator power supply 1
A change in the frequency causes a phase difference in the voltage at both ends of the circuit breaker 3. By detecting this, it can be confirmed that the generator power supply 1 has been disconnected from the other power supply 2.

As a method of detecting the occurrence of the phase difference, a synchronization point detecting device 4 used when interconnecting the generator power supply 1 and another power supply 2 can be used. The synchronization point detecting device 4 compares two power supply voltages and outputs a signal when the phase difference between the two voltages falls within a certain range. Signal is always output because there is no difference between If the two power supplies are disconnected and a difference occurs in the voltage phase, the signal is not output, so that it can be recognized that the two power supplies are disconnected. Note that the method of detecting the phase difference is already known, and thus the description is omitted.

[0009]

As described above, according to the present invention, by measuring the phase difference between both ends of the circuit breaker, it is possible to easily and inexpensively disconnect the generator power supply from other power supplies. It can be confirmed with an apparatus and is extremely useful in practice.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Generator power supply 2 Other power supplies 3 Circuit breaker 4 Synchronization point detection device 5 Load

Claims (2)

[Claims] In a method for confirming disconnection of an output power supply of an alternator having drooping characteristics and a circuit breaker interconnecting another power supply, the number of revolutions of the generator is changed by the drooping characteristics,
When there is a difference between the two voltage phases detected at both ends of the circuit breaker, it is recognized that the output power supply of the AC generator is disconnected from the other power supply by the circuit breaker. How to confirm that the output power of the machine is disconnected from other power supplies. 2. A method for confirming disconnection of an output power supply of an AC generator having no drooping characteristic from a circuit breaker for connecting another power supply to a generator. When the rotation speed changes and a difference occurs between the two voltage phases detected at both ends of the circuit breaker, it is recognized that the output power supply of the AC generator is disconnected from the other power supply by the circuit breaker. A method for confirming the disconnection of the output power of the alternator from other power supplies.