阅读说明：本技术 一种船用岸电箱的岸电电缆过载保护系统 (Shore power cable overload protection system of marine shore power box ) 是由 张优 周玲 王栋 李昱 陆玮 陈俊杰 于 2019-09-10 设计创作，主要内容包括：本发明实施例公开了一种船用岸电箱的岸电电缆过载保护系统,包括一断路器,一电源主线,与断路器的输入端连接；一用于控制断路器通断的分励脱扣器；若干岸电电缆,通过接线端子排与电源主线连接；一用于控制岸电电缆接入数量的多档位选择开关；若干电流互感器和若干继电器,每个继电器与一个电流互感器串联组成控制回路；一电流变送器,与其中一个电流互感器连接,船舶长时间对岸电需求量减较少时,实际连接岸电电缆的数量可以少于满负荷时的电缆数量,不需更换原电路所设断路器,减少了船舶接电缆人员的工作量,能够对所接岸电电缆提供过载保护,防止电缆过载、发热或火灾事故的发生,确保岸电向船舶供电的安全性。(The embodiment of the invention discloses a shore power cable overload protection system of a marine shore power box, which comprises a circuit breaker and a power main line, wherein the power main line is connected with the input end of the circuit breaker; the shunt release is used for controlling the on-off of the circuit breaker; the shore power cables are connected with the power main line through the wiring terminal row; a multi-gear selection switch for controlling the access quantity of the shore power cables; the relay is connected with one current transformer in series to form a control loop; a current transmitter is connected with one current transformer, when the demand of the ship for the shore power is reduced for a long time, the number of actually connected shore power cables can be less than the number of cables under full load, a circuit breaker arranged on an original circuit does not need to be replaced, the workload of personnel for connecting the ship with the cables is reduced, overload protection can be provided for the connected shore power cables, the occurrence of cable overload, heating or fire accidents is prevented, and the safety of supplying power to the ship by the shore power is ensured.)

1. A shore power cable overload protection system of a marine shore power box is characterized in that,

the marine shore power box comprises a circuit breaker (1) arranged in a marine shore power box, wherein the circuit breaker (1) is connected with a shore power box power supply;

a power main line (9) connected with the input end of the circuit breaker (1);

the shunt release (2) is used for controlling the on-off of the circuit breaker (1);

the shore power cables are connected with the power main line (9) through a wiring terminal row (8);

a multi-gear selection switch (3) which is arranged on an operation panel of the shore power box and is used for controlling the access quantity of the shore power cables;

the power supply comprises a plurality of current transformers (5) and a plurality of relays (6), wherein each relay (6) is connected with one current transformer (5) in series to form a control loop, and the input end of the control loop is connected with the power supply main line (9);

a control transformer (4) connected to the power main line (9);

and the current transmitter (7) is connected with one current transformer (5).

2. A shore power cable overload protection system for a marine shore power box according to claim 1, characterised in that the relay (6) has a pair of normally open contacts interlocked with the position signal of the multi-position selector switch (3) and connected with the shunt release (2).

3. The shore power cable overload protection system for the marine shore power box according to claim 1, wherein when the current value measured by the current transformer (5) exceeds the allowable current-carrying capacity of the shore power cable, the normally open contact of the relay (6) of the control loop is closed, and the shunt release (2) starts to be electrified and controls the opening of the circuit breaker (1).

4. The shore power cable overload protection system of the marine shore power box according to claim 3, wherein the circuit breaker (1) further transmits a trip signal to the ship monitoring and alarming system through an auxiliary contact when opening.

5. A shore power cable overload protection system for a marine shore power box according to claim 1, wherein the input of the multi-gear selector switch (3) is connected to the power main line (9) via a control transformer (4), and the output of the control transformer (4) is further connected to the shunt release (2).

6. The shore power cable overload protection system for the marine shore power box according to claim 1, wherein a plurality of position recording switches for recording the total number of the shore power cables are arranged on the multi-gear selector switch (3), and the position recording switches transmit the number information of the shore power cables actually connected to a ship monitoring and alarm system through auxiliary contacts.

7. A shore power cable overload protection system for a marine shore power box according to claim 1, characterized in that the current rating of a number of said current transformers (5) corresponds to the total current carrying capacity allowed by a number of said shore power cables, and the action threshold of said relay (6) corresponds to the current rating of its same set of said current transformers (5).

8. Shore power cable overload protection system for marine shore power boxes according to claim 1, characterised in that the current transmitter (7) monitors the current signal on the shore power cable in real time and transmits the monitoring signal to a vessel monitoring and alarm system.

9. The shore power cable overload protection system for the marine shore power box according to claim 1, wherein the switches on the multi-position selector switch (3) are respectively numbered 1 and 2 … … n, the current transformers (5) are respectively numbered CT, CT1 and CT2 … … CTn, the relays (6) are respectively numbered K1 and K2 … … Kn, the switches with n numbers are connected with the current transformers (5) with CTn numbers and the relays (6) with Kn numbers, and n is a positive integer.

10. The shore power cable overload protection system for the marine shore power box according to claim 1, wherein n shore power cables are connected to a ship when a switch contact of the multi-gear selector switch (3) is in contact with a switch with the number n, and when the n shore power cables are overloaded, a contact of the relay (6) with the number Kn is closed and the shunt release (2) is electrified to act.

Technical Field

The invention relates to the field of power supply systems of ships, in particular to a shore power cable overload protection system of a marine shore power box.

Background

When various ships stop at ports, in order to meet the requirements on the overhaul, maintenance and environmental protection of a generator, a shore power supply is generally connected to provide power distribution for the life and work of the ships, and therefore each ship must be provided with one marine shore power box.

The marine shore power box is suitable for a three-phase alternating-current power distribution system with the working frequency of 50Hz or 60Hz and the rated working voltage of medium-voltage or low-voltage, and provides a quick and safe standard shore power interface for a port-berthing ship. The ship shore power box is connected with the wharf power supply facility through a shore power cable, and specifically is a group or a plurality of groups of single-core or three-core flexible cables.

With the continuous development of marine scientific research, ocean transportation, luxury tourism and other careuses, the demand of various ships on port power supply is higher and higher, the power supply capacity of the marine shore power box is broken through, the number, the length and the weight of the shore power cables are increased, and the workload of a crew for connecting the shore power cables is also increased. But sometimes the power demand of the ship is greatly reduced when the ship does not have large-capacity equipment to operate or service at a wharf or a port. When the demand for shore power is kept at a low level for a long time, only a small amount of shore power cables are generally connected according to the demand in order to reduce the workload of crews, but the problem that a shore power box circuit breaker which is already on board and has a large capacity cannot perform overload protection on the shore power cables which are actually connected in a small amount exists, and accidents such as overload, heating or fire disasters of the shore power cables are easily caused. Based on the current situation, the shore power box which is low in cost, simple to operate, reliable in performance and capable of providing overload protection for the shore power cable is researched and developed, and the significance is profound.

Disclosure of Invention

The invention aims to provide a shore power cable overload protection system of a marine shore power box, so as to solve the technical problems.

The technical problem solved by the invention can be realized by adopting the following technical scheme:

a shore power cable overload protection system of a marine shore power box comprises a circuit breaker arranged in the marine shore power box, wherein the circuit breaker is connected with a shore power box power supply;

the power main line is connected with the input end of the circuit breaker;

the shunt release is used for controlling the on-off of the circuit breaker;

the shore power cables are connected with the power main line through the wiring terminal row;

the multi-gear selection switch is arranged on an operation panel of the shore power box and is used for controlling the access quantity of the shore power cables;

a control transformer connected to the power main line;

each relay is connected with one current transformer in series to form a control loop, and the input end of the control loop is connected with the power main line through the control transformer;

and the current transmitter is connected with one current transformer.

Further, when the current value measured by the current transformer exceeds the allowable current-carrying capacity of the shore power cable, the normally open contact of the relay of the control loop is closed, and the shunt release starts to be electrified and controls the breaker to be opened.

Further, when the breaker is opened, the tripping signal is transmitted to a ship monitoring and alarming system through the auxiliary contact.

Furthermore, the common end of the multi-gear selection switch is connected with the power main line through a control transformer, and the output end of the control transformer is also connected with the shunt release.

Furthermore, a plurality of position recording switches used for recording the total number of the shore power cables are arranged on the multi-gear selection switch, and the position recording switches transmit the number information actually connected into the shore power cables to a ship monitoring and alarming system through auxiliary contacts.

Further, the relay is provided with a pair of normally open contacts which are interlocked with position signals of the multi-gear selection switch and connected with the shunt release.

Further, the current rating of the current transformer is consistent with the total load flow allowed by a plurality of shore power cables, and the action threshold of the relay is consistent with the current rating of the current transformer in the same group.

Further, the current transmitter monitors the current signal on the shore cable in real time and transmits the monitoring signal to a ship monitoring and alarming system.

Furthermore, the switches on the multi-gear selector switch are respectively numbered as 1 and 2 … … n, the current transformers are respectively numbered as CT, CT1 and CT2 … … CTn, the relays are respectively numbered as K1 and K2 … … Kn, the switches with the n-numbered are connected with the current transformers with the CTn-numbered and the relays with the Kn-numbered, and n is a positive integer.

Furthermore, when a switch contact of the multi-gear selection switch is in contact with a switch with the number of n, n shore power cables are connected to a ship, and when the n shore power cables are overloaded, the relay contact with the number of Kn is closed and the shunt release is electrified to act.

Has the advantages that:

the overload protection system can protect the cable incoming line of the shore power box which is not supplied with power under full load, namely, can provide overload protection for the shore power cable which is connected on the premise of not replacing a circuit breaker arranged on an original circuit and reducing the workload of a crew, and is provided with a plurality of groups of auxiliary contacts which can send monitoring and alarming signals to a ship monitoring and alarming system, thereby ensuring the comprehensiveness of monitoring, preventing the occurrence of cable overload, heating or fire accidents, reminding workers to timely maintain damaged shore power equipment or cables and ensuring the safety of the shore power for supplying power to ships.

Drawings

Fig. 1 is an equipment connection diagram of a shore power cable overload protection system of the present invention;

fig. 2 is a circuit connection diagram of the shore power cable overload protection system of the present invention.

In the figure: 1-a circuit breaker; 2-shunt release; 3-a multi-gear selection switch; 4-controlling the transformer; 5-a current transformer; 6-a relay; 7-a current transducer; 8-terminal block; 9-power main line.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The invention is further described with reference to the following drawings and specific examples, which are not intended to be limiting.

The invention aims to provide an overload protection system for a marine shore power box and a shore power cable actually connected with the marine shore power box. After the total number of the shore power cables actually connected to the shore power box is set by the multi-gear selector switch, a current transformer matched with the total allowable load flow of the shore power cables actually connected to the shore power box is put into operation. When the current measured value of the current transformer exceeds the total allowable load flow of the cable, the normally open contact of the relay of the circuit where the current transformer is located is closed, the control circuit of the shunt release of the circuit breaker obtains a power supply, the shunt release acts, the shore power box circuit breaker is opened, and the overload cable is protected. The quantity information of the shore power cables actually connected to the shore power box, current signals flowing through the shore power cables and tripping signals during overload protection of the circuit breaker can be transmitted to a ship monitoring and alarming system in real time for real-time monitoring and alarming. For convenience of description, the shore power box power distribution system of the invention is exemplified by low-voltage AC380V/AC440, and the shore power cable is exemplified by a plurality of groups of three-core flexible cables.

As shown in fig. 1 and fig. 2, the marine shore power box comprises a circuit breaker 1 arranged in the marine shore power box, wherein the circuit breaker 1 is connected with a shore power box power supply;

a power main line 9 connected with the input end of the circuit breaker 1;

a shunt release 2 for controlling the on-off of the circuit breaker 1;

a control transformer 4 connected to the power main line 9;

the shore power cables are connected with a power main line 9 through a wiring terminal block 8;

and the multi-gear selection switch 3 is arranged on an operation panel of the shore power box and is used for controlling the access quantity of shore power cables, the common end of the multi-gear selection switch 3 is connected with a power main line 9 through a control transformer 4, and the output end of the control transformer 4 is also connected with the shunt release 2. The control transformer 4 provides power supply voltage for a control loop consisting of the multi-gear selection switch 3, the normally open contact of the relay 6 and the shunt release 2, so that all devices work under proper voltage and transmit control signals.

The multi-gear selector switch 3 is provided with a plurality of position recording switches used for recording the total number of the shore power cables, and the position recording switches transmit the number information of the actual shore power cables to a ship monitoring and alarming system through auxiliary contacts so as to carry out remote real-time monitoring.

The position recording switches are respectively provided with position labels (1, 2 and … … n), labels of shore power cables (C1 and C2 … … Cn), labels of current transformers (CT, CT1 and CT2 … … CTn) and labels of relays (K1 and K2 … … Kn). If position record switch stops in 5 positions on many gears select switch 3, it has shown to be connected 5 three-core cables between boats and ships and the bank electrical box, and the monitoring of boats and ships monitoring and alarm system can monitor and insert the cable quantity and be 5, and by the control circuit control of current transformer CT5 and relay K5 constitution, guarantee that the cable can not transship.

The current rated values of the current transformers 5 are consistent with the total load flow allowed by the plurality of shore power cables, the action threshold value of the relay 6 is consistent with the current rated value of the current transformer 5 in the same group, and the action threshold value is the current value for enabling the relay 6 to start to generate contact closing or opening action.

It should be added that the rated value of each current transformer 5 is different and is respectively matched with the total allowable load flow of the actual connected shore power cable. Each current transformer 5 is connected in series with a relay 6 to form a control loop, and the action threshold value of each relay 6 is in direct proportion to the rated value of the current transformer 5 connected in series, namely the allowable current-carrying capacity of the shore power cable connected actually. If the allowable current-carrying capacity of each shore power cable is i (a), the action threshold value of the relay 6(K1, K2 … … Kn) is respectively proportional to 1 × i (a), 2 × i (a) … … n × i (a), for example, the action threshold value of the 1 st relay corresponds to the total load flow rate of the 1 shore power cable, the action threshold value of the 2 nd relay 6 corresponds to the total load flow rate of the 2 shore power cables, and so on, the action threshold value of the n th relay 6 corresponds to the total load flow rate of the n shore power cables.

The control circuit comprises a plurality of current transformers 5 and a plurality of relays 6, wherein each relay 6 is connected with one current transformer 5 in series to form a control circuit, and the input end of the control circuit is connected with a power main line 9 through the control transformer 4; the relay 6 is provided with a pair of normally open contacts which are interlocked with position signals of the multi-gear selection switch 3 and connected with the shunt release 2. Namely, the current transformer 5, the relay 6, the multi-gear control switch 3, the shunt release 2, the circuit breaker 1 and the like form a control circuit which detects and disconnects the access cable circuit when the current-carrying capacity of the cable exceeds a rated value, and the tripping process is as follows:

when the current value measured by the current transformer 5 exceeds the allowable current-carrying capacity of the shore power cable, the normally open contact of the relay 6 of the control loop is closed, so that the shunt release 2 is electrified to act, and the circuit breaker 1 is controlled to be opened. When the breaker 1 is opened, a tripping signal is transmitted to a ship monitoring and alarming system through the auxiliary contact, and the alarming system gives an alarm, so that a worker can directly lock a cable which is powered off due to overlarge current, and the power equipment and the cable of the shore power box can be overhauled and maintained in time.

Preferably, the on-off of cable circuits connected with different numbers is controlled by adopting control loops formed by different groups of relays 6 and current transformers 5, the applicability is increased, when cables of a shore power box are not completely connected with a ship, namely when a power system of the shore power box is not in full-load operation, the suitable relays 5 and the current transformers 5 can be selected to control the current-carrying capacity of the shore power cables, so that the overload or the heat generation of the cables is avoided, and the service life of the cables and the safety of a shore power supply system are prolonged.

And the current transmitter 7 is connected with one current transformer 5. The current transducer 7 monitors the current signal on the shore cable in real time and transmits the monitoring signal to the ship monitoring and alarm system. The current transducer 7 can directly convert the alternating current on the shore power cable to be tested into a DC 4-20 mA constant current ring standard signal which is output according to the linear proportion, and continuously transmits the standard signal to the ship detection and alarm system, so that the real-time current amount on the shore power cable can be observed and calculated at any time, and the monitoring safety is improved.

It should be added that, because the shore power box circuit breaker configured in standard is generally equipped with an electronic release or a thermomagnetic release having overload and short-circuit protection functions, and the overload protection set value of the electronic release or the thermomagnetic release is set according to the current value of the shore power box during full-load operation, the current transformer and the control circuit thereof corresponding to the current-carrying capacity of the cable can be closed during full-load operation of the shore power box. And under the condition that the shore power box is not in full-load operation, namely not all shore power cables are connected into the ship, the control loops of the current transformer and the relay are connected into the control circuits of the circuit breaker and the shunt release, so that the safety of the cables can be ensured when a few cables are connected into the ship.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.