SU1436183A1 - Arrangement for automatic connection of stanby source for users - Google Patents

Abstract

The invention relates to emergency response automatics in power supply systems and can be used if there are responsible consumers who do not allow power failure. The goal is to increase reliability and reduce cost. When single phase short circuit on all power supply elements adjacent to the main source, turn on the backup source switch and turn it off after a specified time interval, provided that the active power at the input from the main source does not change its direction or does not become equal to n. by. The backup source switch is turned on if the active power is directed from the main source to the consumer. , 1 zp f-ly, 1 ill. (L with

Description

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ABOUT)

The invention relates to emergency response automatics in power supply systems and can be used if there are responsible consumers that do not allow power interruptions.

The purpose of the invention is to increase reliability and reduce cost.

The drawing shows a block diagram of the proposed device

Current sensors 1 and voltage 2, which represent the overcurrent and voltage relays, are connected to the zero output of the high voltage winding under voltage of the power transformers 3 via current transformers and voltages, respectively.

Sensor 4. The magnitude and direction of the active power is intended for; measurements of active power input from the main source. The sensor has two outputs. At the first output connected to the undercurrent and voltage sensors, the signal appears when the active power is directed from the main source to the consumer. At the second output connected to logic unit 5, the signal appears when the active power is directed from the consumer to the main source food or if it is equal to zero.

Logic block 5 is a combination of AND and OR elements,

- The functions of block 6 of negotiation are to agree on the on time of the on / off switch of the backup source and turn off the on and off switch of the main source. A time relay can be used as a matching unit.

If there are two signals at the inputs of the logic unit 5 - D6 from the matching unit and D4 from the active power sensor, the logic unit outputs the signal D8 D6 to disconnect switch 7 of the main source equipped with the shutdown electromagnet 8.

When only the signal D6 from the matching unit 6 at the second output of the logic unit 5 is present at the input of the logic unit, a signal D10 04 D6 appears to turn off the switch, the backup power source 9, equipped with the shutdown electromagnet 10 and the turn-on electromagnet 11,

The device works as follows.

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Under the influence of the current flowing in the transformer neutral, the corresponding sensor (current 1 or voltage 2) is triggered, from which the signal through the sensor 4 of the direction and magnitude of the active power is supplied to the electromagnet 11 of switching on the reserve source and simultaneously to the matching unit 6. With a single-phase short circuit, the active power is directed to the consumer, therefore, the active power sensor 4 does not prevent the signal from passing.

The switch 9 of the backup source switches on, and the consumer receives power from the main and backup sources simultaneously. Simultaneously, the block of coordination 6 begins to work. At a predetermined time interval j slightly exceeding the time of protection from single-phase earth faults, signal D6 is sent to logic unit 5 from the matching unit. Then, depending on the presence or absence of signal D4 from active power sensor 4, this happens only slightly. d-the current.

The presence of a signal D4 to change the magnitude or direction of the active power of the main source (indicating that the power supply line is disconnected). The logic unit issues a command D8 D4SD8 to turn off the switch 7 of the main source.

Thus, switching of the consumer from the main source to the backup one occurs without power failure,

In the absence of a signal of a change in the magnitude or direction of the active power of the main source (which indicates that a single-phase short circuit does not occur on the supply line from the main source, but, for example, on an adjacent line), logic unit 5 issues a command D10 D4 (§ D8 to switch off the switch of the backup source 10, and the ABP circuit comes in the initial state.

With three and two-phase closures, switching on the backup source switch (before disconnecting input from the main source) does not occur, due to the absence of current in the neutral of the power transformer 3.

In the case of two-phase ground connections, the switch-on of the backup source switch also does not occur due to a sharp decrease in the value of the active power from the main source. In this case, the current flowing in the neutral of a power transformer with single-phase closures depends little on the availability and power of synchronous motors, which makes the device more stable and reliable.

Thus, the proposed scheme provides uninterrupted switching of consumers from the main source to the backup source with single-phase short circuits, i.e. allows you to provide the necessary speed without laying the communication line.

The invention can be implemented on a serially available domestic industry relay or contactless equipment.

Claims (2)

1. A device for automatically switching on a backup power supply of consumers, containing power step-down transformers, main and backup power supply switches with on and off electromagnets, a sensor for the magnitude and direction of the active power of the main source, a matching unit, characterized in that reliability and cost reduction, it includes dat0 five 0 five 0 five The current and voltage neutrals of the high voltage winding of the power transformer and logic unit, the inputs of current and voltage sensors are connected to the zero output of the high voltage winding of the power transformer, and the outputs are connected in parallel and connected to the matching unit, the output of the matching unit and the first output The magnitude and direction sensor of the active power is connected to a logic unit, the first DS output of which is connected to the shutdown electromagnet of the main source switch and connected to the D input from the sensor the magnitude and direction of the active power and the input D of the matching unit with the dependence Dg D 5 Dg, the second output of the magnitude sensor and the direction of the active power of the main source are connected in series to the outputs of the current sensors and the neutral voltage of the high voltage winding of the power transformer. 2. The device according to claim 1, characterized in that the input of the electromagnet of switching on the backup source is connected to the input of the unit: matching, and the input of the electromagnet of disconnecting the backup source is connected to the second output D / ff of the logic unit and is connected to the input from the direction sensor and the magnitude of the active SECURITY D and the input of the DJ unit matching dependency