DE102009059839A1 - Device for use with e.g. electrical switching device for detecting reversal of current direction in photovoltaic strand, has magnetically polarized armature operatively connected with actuator - Google Patents

Abstract

The device (1) has a magnetically polarized armature (15) subjected to magnetic field of a current coil (14) i.e. moving coil, and a pot-shaped magnetic yoke (19). A spring (18) acts upon the armature against direction of action of the magnetic field produced by reverse current. The current coil, the magnetic yoke, the armature and the spring are formed in an arrangement of a usual magnet trigger by switching devices. The armature is operatively connected with an actuator that is designed as an electrical switching element or a magnetic actuating element.

Description

The invention relates to a device for detecting the reversal of current direction according to the preamble of claim 1. The actuator can be used in electrical switching devices for guiding and separating direct current, for example in circuit breakers, motor protection switches, circuit breakers or Trennerv.

From the publication DE 493 280 A For example, there is known a polarized switch which can be used as a fast reverse current switch and which has a current and a voltage coil. The current coil is located on a magnetic core and in series with the switch contacts. The voltage coil is directly connected to the mains voltage with parallel connection of an inductive resistor and serves to polarize a magnet armature designed as a rocker. In the case of a short-circuit current short-circuit, there is a quick release, due to the effect of the inductive resistance even when the mains voltage is not present. The bipolar switch can also be used to shut off a forward current short with increased turn-off time by adjusting the normal position of the armature outside the center position created by the voltage coil. A disadvantage is the high cost of electrical components, their space-consuming arrangement and high energy consumption.

From the publication EP 1 936 651 A2 a trip unit for a DC circuit breaker is known, which has a first and a second magnetic yoke. The magnetic yokes surround a DC bus bar arrangement. The first magnetic yoke is coupled to a magnet armature made of soft iron, which strives for exceeding a certain DC value against the force of a return spring in a triggering position for switching off the circuit breaker. The second magnetic yoke is coupled to a magnetically polarized rotary member connected to a blocking element. By flowing in the busbar arrangement forward current, the rotary member is brought against the force of a spring element in a locking position in which the blocking element prevents displacement of the armature and thus a triggering operation by this armature. Upon occurrence of a reverse current, the rotary member is brought into a release position in which the locking element releases the armature for triggering. A disadvantage is the complicated and component-intensive structure.

The invention is therefore an object of the invention to provide an inexpensive device to realize a reverse current.

Starting from a device of the type mentioned, the object is achieved by the features of the independent claim, while the dependent claims advantageous developments of the invention can be found.

The device according to the invention consists in an uncomplicated manner only of current coil, magnetic yoke, polarized armature and a latter acting spring element. These few device elements are similar in shape and arrangement to a conventional magnetic release of a switching device, but are designed here to detect a reverse direct current. Thus, the device of the invention is structurally simple and inexpensive. The magnet armature is connected to an actuator, through whose diverse choice numerous fields of application for the device according to the invention result. At high forward short-circuit currents, the magnetic field of the current coil is greater than the intrinsic magnetic field of the armature, which is also recognized by the device, and advantageously without the device according to the invention to change or change.

The design of the current coil as a plunger, the yoke in cup form and the armature as a solenoid plunger is an advantageous, formed from conventional Tauchankersystemen form of the invention, for example, to implement in existing switching devices a magnetic release in the form of plunger anchor systems in a simple manner. An immersion anchor system is exemplified in the document DE 43 41 214 A1 shown.

The design of the current coil in conjunction with the magnetic yoke in U-shape and the armature as a hinged armature is an advantageous form of conventional hinged armature systems form of the invention, which is for example to implement in existing switching devices with a magnetic release in the form of a hinged armature system in a simple manner. pamphlet DE 200 10 424 U1 shows an example of a hinged armature system. In certain cases, in particular with high direct currents to be detected, it is sufficient for the current coil to be formed by the section of the current conductor through which the magnetic yoke is linked. Here, the current coil has been reduced to an approximately half turn.

The directly or indirectly operatively connected to the armature actuator is advantageously a trigger mechanism, for. B. with a tripping latch in conjunction with a switching mechanism of a switching device, an electrical switching element, z. B. an auxiliary switch for generating a signal or alarm signal, or a magnetic actuator, z. B. a magnetic energy storage device for triggering a switching mechanism.

The device according to the invention can be used integrated in a disconnector or circuit breaker with advantage to protect the unwanted current direction in a photovoltaic string. When a threshold of the reverse current is exceeded, which may be below the rated operating current of the disconnector or circuit breaker, this state is signaled and / or interrupted by triggering the disconnector or circuit breaker. Reverse currents in solar cells are in fact undesirable, reduce the effectiveness of the solar system, and can even lead to destruction. Permitted return currents are sometimes only slightly above the rated current of the cells. Thus, the solution of the invention stands out clearly from the usual protective measures for photovoltaic strands, the z. For example, special stranded circuit breakers that require over-sized stranded cables in terms of conductor diameter or reverse-poled string diodes that cause high cost and additional power dissipation can be used.

Further details and advantages of the invention will become apparent from the following, with reference to figures explained embodiments. Show it

1 : a schematic representation of a first embodiment of the device according to the invention for detecting the reversal of the current direction;

2 : A schematic diagram of a second embodiment of the device according to the invention for detecting the reversal of the current direction.

The device 1 for detecting the current direction reversal 1 is shown in connection with a switching device of which the contactor 10 and a key switch that actuates it 11 are indicated. The DC current to be detected flows through the current conductor 12 , The switch lock 11 includes a switching device for opening the contact device 10 mandatory trigger mechanism 13 , The device 1 is provided with a current coil 14 equipped by the conductor 12 with the contact apparatus 10 electrically connected in series. The current coil 14 is designed as a plunger coil and for concentrating the magnetic field of a cup-shaped yoke 19 (in 1 dashed lines indicated) surrounded. Inside the power coil 14 is a magnetic anchor designed as a plunger anchor 15 linearly displaceable. The magnet armature 15 is magnetically polarized and therefore made of a permanent magnet 16 and one furthest into the interior of the power coil 14 reaching soft iron part 17 composed. In 1 the orientation of the permanent magnetic field is marked N for magnetic north and S for magnetic south. The magnet armature 15 is with a spring element indicated in the drawing 18 connected. The spring force of the spring element designed as a tension spring 18 acts on the armature 15 in the way that it is from the inside of the current coil 14 wants to move out. The magnet armature 15 is operatively connected to an actuator, in this case the triggering mechanism 13 represents. The from the current coil 14 , the magnet armature 15 and the spring element 18 existing combination is modeled in the form and arrangement of conventional solenoid plunger solenoid releases of switching devices.

In normal current direction, ie at a forward current in the conductor 12 in the direction from + to - according to 1 , is in the power coil 14 formed a magnetic field whose north-south direction in 1 with N and S is indicated. By the directional magnetic fields of current coil at a forward current 14 and magnet armature 15 This will be from inside the coil of electricity 14 repelled. In this case, the trigger mechanism causes 13 no action on the switch lock 11 ,

When reversing the direction of the conductor 12 flowing DC, ie at a reverse current in the direction from - to + according to 1 , is in the power coil 14 formed a magnetic field whose north-south direction in 1 with (N) and (S) is indicated. By oppositely directed at a reverse current magnetic fields of current coil 14 and magnet armature 15 this is contrary to the direction of action of the spring element 18 magnetically applied and into the interior of the current coil 14 drawn. In this case, the trigger mechanism causes 13 a triggering action on the switch lock 11 , in consequence of which the contact apparatus 10 opened and thus the reverse current is interrupted.

The inexpensive device 1 for detecting the reversal of current direction 1 is easy to implement in existing switchgear with plunger anchor system. At high short-circuit currents in the forward direction, this is due to the current coil 14 generated magnetic field greater than the intrinsic magnetic field of the polarized magnet armature 15 , causing the armature 15 pulled into the interior of the current coil and subsequently via the trigger mechanism 13 the opening of the contact device 10 is effected.

The device 2 for detecting the current direction reversal 2 is also shown in connection with a switching device of which the contactor 20 and a key switch that actuates it 21 are indicated. The DC current to be detected flows through the current conductor 22 , The switch lock 21 contains a the switching device for open the contact device 20 mandatory trigger mechanism 23 , The device 2 is with a power coil 24 equipped by the conductor 22 with the contact apparatus 20 electrically connected in series. The current coil 44 is with a magnetic yoke 29 electromagnetically linked. The two Polends 291 and 292 of the U-shaped yoke 29 are in turn with a trained as hinged armature magnet armature 25 magnetically linked. The magnet armature 25 is pivotally mounted with a pivot axis parallel to drawing plane. The magnet armature 25 is magnetically polarized and therefore made of a permanent magnet 26 and one the Polenden 291 . 292 opposite soft iron part 27 composed. In 2 the orientation of the permanent magnetic field is marked N for magnetic north and S for magnetic south. The magnet armature 25 is with a spring element indicated in the drawing 28 connected. The spring force of the spring element designed as a tension spring 28 acts on the armature 25 in the way that he is from the yoke 29 wants to move away. The magnet armature 25 is operatively connected to an actuator, in this case the triggering mechanism 23 represents. The from the current coil 24 , the magnetic yoke 29 , the magnet armature 25 and the spring element 28 existing combination is modeled in the form and arrangement of conventional hinged armature magnetic releases of switching devices.

In normal current direction, ie at a forward current in the conductor 22 in the direction from + to - according to 2 , becomes in the magnetic yoke 29 formed a magnetic field whose north-south direction in 2 with N and S is indicated. Due to the directional magnetic field of magnetic yoke in a forward current direction 29 and magnet armature 25 this one is from the Polenden 291 . 292 repelled. In this case, the trigger mechanism causes 23 no action on the switch lock 21 ,

When reversing the direction of the conductor 22 flowing DC, ie at a reverse current in the direction from - to + according to 2 , becomes in the magnetic yoke 29 formed a magnetic field whose north-south direction in 2 with (N) and (S) is indicated. By the magnetic fields of magnetic yoke oppositely directed at a reverse current 29 and magnet armature 25 this is contrary to the direction of action of the spring element 28 magnetically impinged and from the pole ends 291 . 292 dressed. In this case, the trigger mechanism causes 23 a triggering action on the switch lock 21 , in consequence of which the contact apparatus 20 opened and thus the reverse current is interrupted.

The inexpensive device 2 for detecting the reversal of current direction 2 is easy to implement in existing switchgear with hinged anchor system. At high short-circuit currents in the forward direction, this is due to the current coil 24 generated magnetic field greater than the intrinsic magnetic field of the polarized magnet armature 25 , causing the armature 25 to the magnetic yoke 29 panned and subsequently on the trigger mechanism 23 opening the contact device 20 is effected.

The present invention is not limited to the embodiments described above, but also includes all the same in the context of the invention embodiments. Thus, the invention can be modified, for example, in such a way that as with the magnet armature 15 respectively. 25 operatively connected actuator of an electrical switching element, for example an auxiliary switch for signaling a current direction reversal, or a magnetic actuator, such as a magnetic force storage device for actuating a trigger mechanism 13 respectively. 23 , is provided. When detecting high DC currents, it can in a hinged anchor system 2 be sufficient, the current coil to an approximately half turn in the form of the portion of the current flowing through the DC to be detected conductor 22 to reduce.

LIST OF REFERENCE NUMBERS

1; 2

contraption

10; 20

contactor

11; 21

switch lock

12; 22

conductor

13; 23

trigger mechanism

14; 24

current coil

15; 25

armature

16; 26

permanent magnet

17; 27

Soft iron part

18; 28

spring element

19; 29

yoke

291, 292

pole ends

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 493280 A [0002]
• EP 1936651 A2 [0003]
• DE 4341214 A1 [0007]
• DE 20010424 U1 [0008]

Claims (7)

Device for detecting the reversal of current direction, with a current coil through which the direct current to be detected ( 14 ; 24 ) and one with the current coil ( 14 ; 24 ) linked magnetic yoke ( 19 ; 29 ) - one of the magnetic field of the current coil ( 14 ; 25 ) and the magnetic yoke ( 19 ; 29 ) acted magnetically polarized magnet armature ( 15 ; 25 ) and - a spring element ( 18 ; 28 ), the magnet armature ( 15 ; 25 ) against the direction of action of the magnetic field generated by a reverse current, characterized in that - current coil ( 14 ; 24 ), Magnetic yoke ( 19 ; 29 ), Magnet armature ( 15 ; 25 ) and spring element ( 18 ; 28 ) are formed in the form and arrangement of conventional magnetic releases of switching devices and - the armature ( 15 ; 25 ) is operatively connected to an actuator. Contraption ( 1 ) according to claim 1, characterized in that the current coil ( 14 ) as a plunger, the magnetic yoke ( 19 ) cup-shaped and the magnet armature ( 15 ) are designed as linearly displaceable plunger armature. Contraption ( 2 ) according to claim 1, characterized in that with the pole ends ( 291 . 292 ) of the U-shaped magnet yoke ( 29 ) of the armature designed as a pivotable hinged armature ( 25 ) is magnetically linked. Contraption ( 2 ) according to the preceding claim, characterized in that the current coil on the with the magnetic yoke ( 29 ) chained portion of the traversed by the DC current to be detected conductor ( 22 ) is reduced. Device according to one of the preceding claims, characterized in that the actuator as a switching device for switching off mandatory trigger mechanism ( 13 ; 23 ) is trained. Device according to one of the preceding claims, characterized in that the actuator is an electrical switching element. Device according to one of the preceding claims, characterized in that the actuator is a magnetic actuator.

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