FR2460060A1 - ELECTRONIC TRIGGER - Google Patents

Abstract

ELECTRONIC TRIP FOR A COUPLING DEVICE, CONTAINING SEPARATE CHANNELS FOR OVERLOAD TRIP AND SHORT-CIRCUIT TRIP, AS WELL AS BLOCKS FOR MEASUREMENT PRE-PROCESSING AND POWER SUPPLY. THE ELECTRONIC TRIP UNIT INCLUDES SPECIAL 22-25 INPUTS INTENDED FOR CONNECTING A CALIBRATION DEVICE, WHICH SIMULATES THE SIGNALS IN SERVICE OF THE MEASURED VALUES AND OF THE POWER SUPPLY.

Description

2460060-

  The present invention relates to an electronic trigger for

  a coupling apparatus having separate channels for a

  overload trip and trip by short circuit,

  as well as blocks for the processing of the measured values and the

  mentation. Such triggers generally comprise a channel b for the detection of overload currents and channels s and k for the detection of short-circuit currents. The channel b operates with a characteristic adapted for example to the destruction characteristic of the device to be protected or to the characteristic of a bimetallic trigger with thermal delay, and simulated by electronic means. When the adjusted threshold is reached or exceeded, a delayed tripping of the circuit breaker occurs depending on the

  current-time characteristic. Channels s and k detect

  short circuit, the channel s having a time delay to allow a selective staggering over time protection organs distribution facilities, while the k channel operates without delay. The current thresholds of channels s and k are continuously adjustable. The delay of the channel s is adjustable continuously or in stages. Additional blocks are also provided for entering or pre-processing the measured values and for the voltage supply. The measurement signals are transmitted from the preprocessing to the various channels in which the occurrence of a fault decurrent produces triggering signals, acting on an electromagnetic trigger to cause the tripping of the circuit breaker. The voltage supply can be carried out using an external power supply or be produced by transformers

  measured, mounted on the main current paths.

  Calibration of such triggers is done in a known manner, at

  for example, a particularly costly control device

  including a control transformer which delivers the power

  control and auxiliary voltages required for calibration.

  The necessary simulation of the conditions of service implies a

  important fencing. Calibration is performed by the normal inputs of the pre-treatment of the measurements or the supply. The state of service

normal is thus established.

  The invention aims, with simple means, to carry out a

  the triggers mentioned above or to check the values

  by prior calibration. According to an essential characteristic

  of the invention, the trigger includes special inputs for connecting a calibration apparatus, which allows

  to simulate the in-service signals of the measured values and the

  mentation. Such a special calibration device, in the form of a small suitcase for example, allows an easy and simple simulation of the measurement signals, without important equipment. The

  supply voltage of such a trigger may further be pro-

  using simple means. The invention thus eliminates the need for a special and expensive control transformer, which must deliver the currents to be monitored and whose measurement signals are derived by measuring transformers. The measured values, which are small in relation to the intense currents in use, are according to the invention produced directly in the calibration apparatus and then applied to the special inputs. According to another characteristic of the invention, these special inputs are provided at the input of the channels and the power supply unit, and connectable to the calibration apparatus by a calibration socket mounted on the trigger. This take

  calibration is preferably combined with an existing test

  so much already. The invention allows a local calibration in a minimal time,

  as well as easy adaptation to modified service conditions.

  The meeting of the test and calibration jacks allows a functional check of the device as well as a calibration check of

  thresholds, trip characteristics and delays.

  A downstream electromagnetic current-operated actuator trips the circuit-breaker as soon as the thresholds set in channel b or channels s and k are reached and exceeded. The channel b operates with a long delay and the channel s with a short delay, while the channel k operates without delay, that is to say only with a proper response time. Depending on the value of the incoming overcurrent, tripping of the circuit breaker occurs after a long delay, as in channel b, or a short delay, as in

  the channel s. A longer or shorter time thus elapses between the

  both the adjusted current threshold is reached and the tripping of the circuit breaker. According to another characteristic of the invention, during the occurrence of an overcurrent, the instant when the thresholds adjusted in the channels are reached is detected directly and without delay by the calibration inputs and / or special blocks of the editing, then

  translated by appropriate signals of said blocks. It is thus pos-

  sible to prepare or apply provisions as soon as the adjusted current thresholds are reached. It thus becomes useless to wait for the failure, that is to say the final trigger

  circuit breaker, in order to make appropriate arrangements.

  It is even possible to immediately detect if the adjusted thresholds are reached. From this moment, it is possible for example to apply a decision in the long-delay channel b for example, without waiting for the

  circuit breaker tripping. According to another characteristic of the in-

  the signals detecting the instant of occurrence of an overcurrent are indicated immediately by display elements, such as

  electroluminescent diodes in the trigger assembly blocks.

  A disturbance is indicated well before the trip

delayed breaker.

  According to another characteristic of the invention, the signals de-

  directly the moment of overcurrent occurrence are used.

  to produce an action before triggering the coupling apparatus by the channel in question. A long-delay channel b for example can be used to apply a suitable arrangement for cutting another branch, as soon as the current threshold is reached and before the end of the triggering of the coupling device. It is the same in principle for the channel s low delay. According to another characteristic of the invention, signals directly detecting the instant of occurrence of an overcurrent are

  translated through terminal blocks of the mounting blocks or

  by additional contacta of the test plug.

  Other features and advantages of the invention will be

  better understood using the detailed description below of a

  exemplary embodiment and the accompanying drawings in which:

  FIG. 1 represents the block diagram of an exemplary embodiment

tion and

  FIG. 2 represents the block diagram of an exemplary application of

of the invention.

  FIG. 1 shows a three-phase circuit 10, which a contact system 11 of a coupling apparatus, not shown, makes it possible to interrupt by means of a trigger 12 with a working current. The

  trigger 12 receives its trigger signals 13 of a trigger

  electronically represented schematically in the synoptic diagram. -

  The current supply 14 of the electronic trip unit is provided by current transformers 15, mounted in the coupling device on parts of the main circuit. Measuring signals

  are supplied by special measuring transformers 16, which can

  can be connected with current transformers 15 and are also

  mounted on separate parts of the main circuits; a preprocessing block 17, comprising a rectifying circuit, delivers the measurement signals to a channel b 18, a channel s 19 and a channel k 20. The channel b provides overload tripping; the channel s and the channel k ensure the tripping by short circuit. The

  channel s has a short adjustable delay. The trigger signals

  13a, 13b, produced in the various channels by the occurrence of a fault current, act on the electromagnetic actuator 12 working current, which triggers the coupling device. The test and calibration plug 21 is connected by wires 22 to 26 to the inputs of the power supply 14 and the channels 18, 19, -20, as well as to the output

  delivering the trigger signal 13. This test port 21 permits

  on the one hand to control the operation of the electronic trigger

  and calibrate or verify the values provided by. a calibration already done. The operating signals of the supply voltage and the three channels are simulated with the aid of a special calibration apparatus, not shown. Such a montage

  eliminates the important equipment usually required

  for a calibration, with a control transformer for the

  commissioning of the entire installation.

  The instant when the adjusted current threshold in the channels is

  reached can be detected for example by means of the standard entries

2460060-

  23-25, not used in normal service for calibration. Two

  additional blocks 27, 28 are also provided for the determination

these moments.

  These instants may be indicated by means of diodes

  luminescent 27a for example in the blocks 27, 28 and / or be applied by special outputs 29, 30 to the calibration tap 25 and

  thus serve for additional switching instructions.

  The calibration plug 21 comprises the contacts 31 to 35. The contact 31 delivers the supply voltage U to the electronics. The

  contacts 32, 33 and 34 each deliver a corresponding measuring signal.

  at the adjusted threshold: Ub for channel b, U for channel s or Uk

  for channel k. The trigger signal Ua appears on the con-

  tact 35 when triggering the channel in question. Internal light-emitting diode signaling is produced simultaneously

in the mounting blocks 36, 37.

  The measurement of the time difference between the application of the

  The measurement signal and the occurrence of the trigger signal allow a control of the tripping characteristic in channel b, a basic delay control in channel s / k and further the control of the adjustable delay in channel s. The message "exceeded threshold" is

  displayed when responding to various channels.

  FIG. 2 represents an exemplary embodiment of a distribution

  with a high-voltage circuit breaker 38, a low-voltage circuit breaker 39 and three other low-voltage circuit breakers 40 to 42. The circuit breaker 39 is adjusted for example with a delay of 300 ms and

  circuit breakers 40 to 42 with a delay of 200 ms each. The disc

  junction 39 comprises an electronic release according to FIG.

  In the normal case, a short circuit in the use Ml produces

  The circuit breaker 40 is tripped after 200 ms because circuit breaker 40 is adjusted for this delay. The instant of appearance of the short circuit is however detected in the circuit breaker 39 according to

  invention, so that the signal thus obtained is immediately used.

  sand for the tripping of the circuit-breaker 41, as indicated by the dash 43. When an overcurrent of given value (overload or short-circuit current) occurs, it is thus possible to respect the order of shut down parts of the required installation

  for continued operation.

  Of course, various modifications may be made by those skilled in the art to the principle and to the devices which have just been described solely by way of nonlimiting examples, without

depart from the scope of the invention.

Claims (7)

claims   1. Electronic trigger for a coupling device, comprising   both separate channels for an overload trip and a   triggering by short-circuit, as well as blocks for the pre-   processing of the measured values and the power supply, said trigger being characterized by special inputs (22-25) for connecting a calibration device, which makes it possible to simulate the   signals in service of the measured values and the power supply.   Trigger according to claim 1, characterized in that the special inputs (22-25) are provided at the input of the channels (18,   19, 20) and the power supply unit (14), and connectable to the   calibration wire by a calibration plug (21) mounted on the trigger.   Trigger according to one of claims 1 and 2, characterized by   the meeting of the calibration plug (21) and a test plug.   4. Trigger according to any one of claims 1 to 3,   characterized in that when an overcurrent occurs, the   when the thresholds adjusted in the channels (18, 19, 20) are reached is detected directly and without delay by the calibration inputs (22-25) and / or special blocks of the assembly (27, 28), then translated   by appropriate signals of said blocks.   5. Trigger according to claim 4, characterized in that the   signals directly detecting the moment of appearance of a surinten-   are immediately indicated by display elements   (light-emitting diodes 27a) in the mounting blocks (27, 28).   6. Trigger according to claim 4, characterized in that the   signals directly detecting the moment of appearance of a surinten-   are used to produce an action (instructions for   tation) before triggering the coupling device by the channel considered (18, 19, 20).   7. Trigger according to one of claims 4 and 6, characterized   in that the signals directly detecting the instant of occurrence of an overcurrent are translated via terminals (29,   ) of the mounting blocks (27, 28) or detected by   of the test plug (21).