CN112098832A - Device for detecting tripping characteristic of pole-mounted circuit breaker - Google Patents

Abstract

The invention relates to a tripping characteristic detection device of a pole-mounted circuit breaker, which comprises an inverter (1) connected with a direct current input end (12), and a voltage regulation shunt and a voltage loss regulation shunt which are respectively connected with a three-phase alternating current output end of the inverter (1), wherein the voltage regulation shunt is connected with a power supply side three-phase output end (10) and a load side three-phase output end (11), the voltage loss regulation shunt is connected with the power supply side three-phase output end (10), and the inverter, the voltage regulation shunt, the voltage loss regulation shunt, the power supply side three-phase output end (10) and the load side three-phase output end (11) form a three-phase detection loop. Compared with the prior art, the invention has the advantages of high detection efficiency, low cost, no need of climbing rod detection and the like.

Description

A device for detecting the tripping characteristics of a circuit breaker on a pole

technical field

The invention relates to a power instrument, in particular to a device for detecting the tripping characteristics of a circuit breaker on a pole.

Background technique

The circuit breaker on the column is used for the connection, segment and branch line in the power grid, and it is the core component of the modern intelligent distribution network. The pole-mounted circuit breaker is a highly integrated power equipment, which integrates primary and secondary equipment such as analog quantity acquisition, relay protection, circuit breaker arc extinguishing mechanism, etc. There are more new requirements.

Because the pole-mounted circuit breakers are often installed on the poles of each distribution network branch line, it is difficult to test their characteristics, especially the trip characteristics of the circuit breaker and the test of the relay protection action characteristics must be completed by climbing the pole. Generally, secondary professionals do not have the ability to work at heights on the pole, but those with the ability to work at heights do not have the professional knowledge of secondary control and protection equipment, which makes the on-site inspection of the circuit breaker on the pole need to cooperate with various types of work, and the operation efficiency is very low. , and the number of circuit breakers on the column is extremely large, which leads to the fact that many power supply departments often fail to check all circuit breakers in their jurisdiction on schedule, causing hidden dangers to future operations. In the summer high temperature season, the sudden failure of the circuit breaker on the column or the accidental tripping accident often occurs. However, under the existing conditions, there are almost no methods and habits for power failure verification or live detection on the column circuit breaker of important circuits. It helps to greatly improve the reliability of distribution network operation.

The prior art generally adopts the tripping scheme based on the high-current generator, but this scheme has the following shortcomings: 1) It is inconvenient to use: a large number of circuit breakers are installed on the column, and the high-current generator is very heavy and heavy, and a 1000A high-current generator is heavy. It is more than 30 kg, which brings great inconvenience to the on-site mobile detection operation; in addition, the existing high-current generators are single-phase output considering the convenience of power supply, and three-phase pole-mounted circuit breakers need to be tested three times to realize the detection. , which increases the inconvenience of work. 2) The real load current change process cannot be simulated. 3) High cost: the prior art switch tripping characteristic detection device based on the design of the high current generator requires a large-capacity primary current transformer and an auto-voltage regulator, because both are power-frequency single-phase inductive components, which It consumes a lot of copper and iron, and the price of 1000A products is at least 10,000 yuan, which is very expensive.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a device for detecting tripping characteristics of a pole-mounted circuit breaker with high detection efficiency, low cost, and detection of real arc extinguishing capability and three-phase synchronous characteristics of switches in order to overcome the above-mentioned defects in the prior art.

The object of the present invention can be realized through the following technical solutions:

A device for detecting the tripping characteristics of a circuit breaker on a column, comprising an inverter connected to a DC input end, a voltage regulation shunt and a voltage loss regulation shunt respectively connected to a three-phase AC output end of the inverter. The shunt is connected to the three-phase output terminal of the power supply side and the three-phase output terminal of the load side. The shunt, the three-phase output terminal on the power supply side and the three-phase output terminal on the load side form a three-phase detection circuit.

The voltage loss regulating branch includes three-phase voltage loss buttons, three voltage transformers and three voltmeters, and the voltage loss buttons of each phase are respectively connected with a low voltage winding of the voltage transformer and a voltage transformer. The meters are connected in parallel, the common terminals of the high-voltage windings of the voltage transformers are connected in parallel to form a zero phase, and the phase line terminals of the voltage transformers are respectively connected to the three-phase output terminals of the power supply side.

The voltage regulating shunt includes a voltage regulator, an ammeter and a current adding button, and the three-phase output ends of the voltage regulator are respectively connected in series with the ammeter and the current adding button, and then connected to the primary winding of a primary current transformer, The secondary windings of each primary current transformer are respectively connected to the three-phase output terminal of the power supply side and the three-phase output terminal of the load side.

Further, the zero-phase loop of the three-phase output end of the voltage regulator is also connected in series with the primary winding of the secondary current transformer, and the secondary winding of the secondary current transformer is connected to the signal input end of the electrical signal timer. .

In actual work, the inverter converts the DC low-voltage power supply into AC voltage, and after setting different voltages through the three-phase voltage regulator, the current amplification is realized by the reverse connection of the primary current transformer, thereby generating the three-phase circuit breaker on the column. Phase test current; the inverter forms the three-phase test voltage of the circuit breaker on the column through the three-phase voltage loss button and each current adding button, after the voltage transformer is reversely connected and boosted; during the detection process, if the three-phase If the voltage loss button and each current adding button are opened at the same time, it means that the synchronization of the three-phase detection circuit is good, and the electric signal timer shows the short time of the unbalanced current in the zero phase. The arc capacity is reduced and the electrical signal timer shows the duration of the unbalanced current in the zero phase for a long time.

Further, the three voltage transformers are three independent single-phase voltage transformers.

Further, each primary current transformer is an independent single-phase current transformer.

Further, the three-phase voltage loss button and each current adding button are normally closed contact buttons.

Compared with the prior art, the device for detecting the tripping characteristics of the circuit breaker on the pole provided by the present invention at least includes the following beneficial effects:

1) The detection efficiency is high, and three-phase detection is possible at the same time: the present invention adopts the inverter to realize the output current regulation. Since the inverter has the innate AC-DC-AC conversion function, the ordinary single-phase power supply can be used to generate the three-phase detection current, Realize three-phase simultaneous detection of three-phase switches, which greatly improves the efficiency of on-site detection operations;

2) Low cost: the present invention can use the scrapped current and voltage transformers close to the service life to realize the functions of the step-up transformer and the step-up transformer. To the outstanding effect of resource recycling and turning waste into treasure;

3) No need for pole-mounting test: the present invention only needs to hook up six test poles, so that the circuit breaker on the pole can be tested conveniently on the ground, which avoids the problem of complex pole-mounting testing and potential safety hazards, and further improves the field operation efficiency;

4) The real arc extinguishing ability and three-phase synchronization characteristics of the switch can be detected: the invention cleverly uses the ability of three-phase simultaneous detection, and detects the synchronization of three-phase actions by using an electric signal timer to time the zero-phase current, and fundamentally finds that The hidden danger of three-phase inconsistency that may exist in the switch;

5) The primary item and the secondary item can be detected at the same time: the present invention can detect the action time limit of the circuit breaker, the three-phase synchronization, and the accuracy of the relay protection action through the primary side current injection. The ability of one-time inspection is self-evident for the improvement of operation efficiency;

6) Most of the detection items of the circuit breaker on the column are covered by simple means, and the hidden danger of the switch running with illness is completely avoided: the means adopted in the present invention are all from cheap idle or eliminated equipment, and the column is realized at a very low cost. The health of the upper circuit breaker is fully checked.

Description of drawings

Fig. 1 is the principle structure schematic diagram of the trip characteristic detection device of the circuit breaker on the column in the embodiment;

The numbers in the figure show:

1. Inverter, 2. Voltage regulator, 3. Primary current transformer, 4. Electric signal timer, 5. Secondary current transformer, 6. Ammeter, 7. Voltage transformer, 8. Voltmeter, 10 , The three-phase output terminal of the power supply side, 11, the three-phase output terminal of the load side, 12, the DC input terminal, 13, the current adding button, 14, the voltage loss button.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

Example

As shown in FIG. 1 , the present invention relates to a device for detecting tripping characteristics of a circuit breaker on a column, which includes an inverter 1, a voltage regulator 2, a primary current transformer 3, an electrical signal timer 4, and a secondary current transformer 5. Three-phase ammeter 6, three-phase voltage transformer 7, three-phase voltmeter 8, three-phase output terminal on power supply side 10, three-phase output terminal on load side 11, DC input terminal 12, current adding button 13 and voltage loss button 14 .

The DC power input terminal of the inverter 1 is connected to the DC input terminal 12. The three-phase AC output terminal of the inverter 1 is divided into two channels, one is connected to the input terminal of the voltage regulator 2, and the other three-phase AC output terminals are respectively connected Decompression button 14.

The three-phase output terminals of the voltage regulator 2 are respectively connected with the ammeter 6 and the current adding button 13 in series, and then connected to the primary winding of a primary current transformer 3; the secondary windings of each primary current transformer 3 are respectively connected to the power supply. The three-phase output terminal 10 on the side and the three-phase output terminal 11 on the load side.

The zero-phase loop of the three-phase output end of the voltage regulator 2 is also connected in series with the primary winding of the secondary current transformer 5 , and the secondary winding of the secondary current transformer 5 is connected to the signal input end of the electrical signal timer 4 . The electrical signal timer 4 is used to record the unbalanced current time existing in the zero phase, and the long and short display of the time is used to reflect the detection of the synchronicity of the three-phase action, and then find the problem of arc extinguishing or the problem of three-phase inconsistency.

The three-phase voltage loss button 14 is also connected in parallel with the low-voltage windings of the three voltage transformers 7 and the three voltmeters 8 respectively; The side three-phase output terminals 10 are connected. The three voltage transformers 7 are three independent single-phase voltage transformers; each primary current transformer 3 is an independent single-phase current transformer.

The three-phase voltage loss button 14 and each current adding button 13 are normally closed contact buttons.

The principle of the present invention is also to use a large current to trip the circuit breaker on the tested column, and then detect whether its various operating characteristics meet the requirements, but the implementation method has many similarities and differences with the prior art, so that more prominent beneficial effects are obtained.

First of all, there are a large number of scrapped current and voltage transformers that are close to the service life in power companies or other production plants and related companies. The DC low-voltage power supply, such as the 12V battery of the maintenance vehicle, is converted into a higher AC voltage. After the three-phase voltage regulator is set to different voltages, the primary current transformer is connected upside down to realize the current amplification, so as to realize the three-phase circuit breaker on the column. The generation of phase test current; the protection of the circuit breaker on the column has low voltage requirements, and only needs to verify that the low-voltage trip can be managed. Therefore, the three-phase voltage is not regulated by a voltage regulator, but directly through the normally closed contact button and through the voltage transformer. The three-phase test voltage of the circuit breaker on the column is formed after the boost is reversed. Since the test current and voltage are both high-voltage signals injected from the primary side, it is guaranteed that the primary and secondary equipment can be tested at the same time, which realizes the globality and high efficiency of the experiment, and makes full use of the scrapped and idle equipment to achieve resource recycling. , The outstanding effect of turning waste into treasure.

Secondly, the invention realizes the detection of zero-phase current by constructing a three-phase detection circuit, and can sensitively reflect the arc extinguishing problem or the three-phase inconsistency problem through the timing of the zero-phase medium electric signal timer. Open, the synchronization is good, the time of unbalanced current in the zero phase is very short, if a phase moves slowly or the arc extinguishing ability is reduced, there will be unbalanced current in the zero phase for a long time, so the time is measured by the electrical signal The device can intuitively and clearly detect the problem of three-phase inconsistency or reduced arc extinguishing ability.

The invention is also very convenient to use, and only needs to hang the six signal output ends of the three phases on both sides of the three-phase break of the circuit breaker on the pole to be tested.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited to this. Any person familiar with the technical field can easily think of various equivalents within the technical scope disclosed by the present invention. Modifications or substitutions should be included within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims (8)

1. A device for detecting tripping characteristics of a circuit breaker on a column, characterized in that it comprises an inverter (1) connected to a DC input end (12), and an inverter (1) connected to a three-phase AC output end of the inverter (1) respectively. A voltage regulation shunt and a voltage loss regulation shunt, the voltage regulation shunt is connected to the three-phase output terminal (10) on the power supply side and the three-phase output terminal (11) on the load side, and the voltage loss regulation shunt is connected to the three-phase output terminal on the power supply side an output end (10), the inverter, the voltage regulation shunt, the voltage loss regulation shunt, the three-phase output end (10) on the power supply side and the three-phase output end (11) on the load side A three-phase detection circuit is formed. 2 . The trip characteristic detection device of a circuit breaker on a pole according to claim 1 , wherein the voltage loss regulating shunt comprises a three-phase voltage loss button (14), three voltage transformers (7) and three a voltmeter (8), the voltage loss buttons (14) of each phase are connected in parallel with the low-voltage winding of one of the voltage transformers (7) and one of the voltmeters (8), and each of the voltage transformers ( 7) The common ends of the high-voltage windings are connected in parallel to form a zero phase, and the phase line ends of each of the voltage transformers (7) are respectively connected to the three-phase output ends (10) on the power supply side. 3. The device for detecting tripping characteristics of a circuit breaker on a pole according to claim 2, characterized in that the voltage regulating shunt comprises a voltage regulator (2), an ammeter (6) and a current adding button (13). The three-phase output terminals of the voltage regulator (2) are respectively connected in series with the ammeter (6) and the current adding button (13) and then connected to the primary winding of a primary current transformer (3). 3) The secondary winding is respectively connected to the three-phase output terminal (10) on the power supply side and the three-phase output terminal (11) on the load side. 4. The device for detecting trip characteristics of a circuit breaker on a pole according to claim 3, wherein a secondary current transformer (5) is also connected in series with the zero-phase loop of the three-phase output end of the voltage regulator (2). The primary winding of the secondary current transformer (5) is connected to the signal input end of the electrical signal timer (4). 5. The device for detecting trip characteristics of a circuit breaker on a pole according to claim 4, wherein the inverter (1) converts the DC low-voltage power supply into an AC voltage, and is set through a three-phase voltage regulator (2). After different voltages, the primary current transformer (3) is reversely connected to realize current amplification, thereby generating the three-phase test current of the circuit breaker on the column; the inverter (1) communicates with each The current adding button (13) is connected upside down through the voltage transformer (7) to form the three-phase test voltage of the circuit breaker on the column; 13) Open at the same time, it means that the three-phase detection circuit has good synchronicity, and the electrical signal timer shows the short time of the unbalanced current in the zero phase. The timer shows the duration of the unbalanced current in phase zero. 6 . The device for detecting tripping characteristics of a circuit breaker on a pole according to claim 2 , wherein the three voltage transformers ( 7 ) are three independent single-phase voltage transformers. 7 . 7 . The device for detecting trip characteristics of a circuit breaker on a pole according to claim 3 , wherein each primary current transformer ( 3 ) is an independent single-phase current transformer. 8 . 8 . The tripping characteristic detection device of a circuit breaker on a pole according to claim 3 , wherein the three-phase voltage loss button ( 14 ) and each current adding button ( 13 ) are normally closed contact buttons. 9 .

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