Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
  • H01H9/16—Indicators for switching condition, e.g. "on" or "off"
  • H01H9/168—Indicators for switching condition, e.g. "on" or "off" making use of an electromagnetic wave communication
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H47/00—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current
  • H01H47/002—Monitoring or fail-safe circuits
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H50/00—Details of electromagnetic relays
  • H01H50/08—Indicators; Distinguishing marks

Definitions

• the invention relates to an electronic switching magnet control for contactors, the protection having a displacement sensor with which the position of the armature can be determined, and the switching magnet control a measuring sensor that determines the actual current in the armature coil of the contactor, a current Target generator, which specifies a target current as a function of the position of the armature, and has a voltage regulator which specifies the voltage applied to the armature coil as a function of the current deviation between the actual current and target current.
• DE 44 09 010 AI describes a switching device in which the position of the movable member, in particular the armature of a protection, can be determined during the switching process by means of a sensor.
• the sensor is a potentiometer, consisting of an elongated sensor element and a movable rotor attached to the armature, which is supported on the sensor element.
• the coil current is controlled over the entire displacement distance during the switching process, which on the one hand increases the closing force of the protection and on the other hand improves the electrical and mechanical durability of the device.
• a current meter is connected in series to the coil.
• the coil current is controlled as a function of the difference between the target coil current and the measured actual coil current by means of a pulse modulation circuit, the coil current depending on the level of the pulse size modulation.
• a potentiometer as a position sensor has several disadvantages.
• the resistance of the potentiometer is temperature-dependent, so that the actual position of the armature in the event of temperature fluctuations cannot be determined by the switching device without additional outlay on circuitry.
• the armature moved by the coil is braked by the required pressing force of the sliding contacts of the potentiometer, which increases the coil current unnecessarily and thus reduces the electrical durability. Due to the relatively fast movement of the armature, the resistance area of the potentiometer is additionally stressed, which leads to changes in resistance due to detachment or abrasion of the resistance material. In this case, it is no longer possible to control the contactor.
• the object of the invention is therefore to further develop an electronic solenoid control of the type mentioned above in such a way that the position of the armature can be determined without the force exerted on the armature, the position determination being independent of any temperature fluctuations.
• the displacement sensor has a number n sensors, in particular mechanical switches, light barriers, Hall detectors or induction switches, which are arranged along the stroke distance to be covered by the armature and by means of which the position of the armature can be discretely determined, and that each sensor of the displacement sensor a target current value is assigned.
• n sensors in particular mechanical switches, light barriers, Hall detectors or induction switches, which are arranged along the stroke distance to be covered by the armature and by means of which the position of the armature can be discretely determined, and that each sensor of the displacement sensor a target current value is assigned.
• the target current is a function of the position of the armature or a function of the time and position of the armature. Due to the position-dependent current specification, a higher target current can advantageously be specified at the beginning of the switching process. As soon as the armature or the switching contacts have been accelerated and a maximum speed has been reached, the inertia of the armature is sufficient to move the armature into the ON position. The current through the coil can therefore be small compared to the initial current, since smaller acceleration forces are sufficient to accelerate the armature.
• a maximum target current is advantageously specified again at the end of the switch-on process so that the armature is pressed firmly against the fixed parts of the magnetic circuit. Since the armature and the switching contacts of the protection are not rigidly connected to one another, the armature can be moved a smaller distance after the switching contacts have closed. This distance is also known as the residual anchor stroke. It has now been shown that a defined armature speed during the closing of the switch contacts of the protection means that the contact bounce of the switch contacts can be considerably reduced and thus an increase in the service life.
• the n sensors are distributed at equal distances from one another over the stroke distance. are arranged.
• the sensors recognize the armature or its markings, passages, protrusions or depressions and each send a specific signal to the switching magnet control.
• the first sensor recognizes or detects the armature or its markings immediately after leaving the rest position or the exhibition.
• the last sensor recognizes or detects the armature or its markings immediately before reaching the stop position or the ON position.
• the ON position of the contactor is the position in which the circuit is closed. The position and speed of the armature can thus be determined precisely. The greater the accuracy requirements for determining the position and / or the speed, the higher the number of sensors to be selected.
• the optimal target current values are determined empirically or arithmetically and stored in a memory.
• the target current values or the course of the target current curve depend crucially on the length of the stroke, the inertia or mass of the armature and the switching contacts attached to it.
• the switch-on process can be started, for example, by a start signal. However, it is also possible that the switch-on process is started when the supply voltage of the solenoid control exceeds a certain value. It is particularly advantageous if, at the beginning of the switch-on process, the current setpoint generator specifies a constant current profile or degressive or ramped current profile, each starting from zero, until the first sensor detects the armature or its markings by moving the armature and has given a corresponding signal to the switching magnet control. As soon as the first sensor or one of the subsequent sensors the anchor or its markings is detected, the So11 current value associated with the corresponding sensor is read from the memory. This nominal current value transmitter is specified by means of the current nominal value transmitter until the next sensor detects the armature or the markings, in which case another nominal current value is then generally specified.
• a timer is also advantageously reset and started. For circuitry reasons, it is proposed to use only one timer. If only one timepiece is used, the timepiece must be reset and restarted each time the anchor is detected by a new sensor. However, it is also conceivable for the timer to run continuously and for the time to be stored in a memory each time the armature is detected by a new sensor. By comparing the stored time with the elapsed time, it is then also possible to determine the time that has passed since the anchor was detected by the previous sensor.
• a certain time for driving through a distance determined by two sensors is exceeded, this is evaluated as an error and the switching magnet control is caused to abort the switch-on process or to start an emergency aid program for a predeterminable time. If the next sensor is not reached even after the emergency time has elapsed, the switch-on process is finally stopped. During the duration of the emergency aid program, a maximum target current is advantageously specified in order to accelerate a possibly stuck armature with the maximum available force. If the next sensor detects the anchor within the duration of the emergency aid program, the switch-on process is continued as normal.
• a maximum time is predefined for each section of the stroke distance determined by two sensors arranged next to one another, after the anchor must reach the next sensor.
• the maximum time is also stored in a memory.
• a plurality of setpoint current values are assigned to each sensor of the displacement sensor, the setpoint current values assigned to a sensor each being assigned to different time intervals. This is particularly advantageous if, depending on the inertia or sluggishness, the armature and the moving parts operatively connected to it are fast or slow. If the anchor reaches e.g. relatively quickly a certain sensor, this is a sign that the armature can be accelerated without great effort. It is therefore not necessary to specify large target current values. If a relatively long time elapses before the armature is detected by a specific sensor, this is a sign of a great inertia of the armature and the parts that are operatively connected to it.
• the further desired current values to be specified should be selected accordingly.
• the time interval which has elapsed since the start of the switch-on process or since the detection of the sensor in front of it has therefore been determined in this embodiment. Then, in accordance with this time interval, the target current value associated with this sensor and the time interval is read out of the memory and specified by means of the target current value transmitter.
• the current setpoint generator starts a holding program as soon as the switch-on process has been successfully completed or after the last sensor has detected the armature or its markings.
• the current setpoint generator specifies the holding current, the strength of the holding current being dimensioned such that the force generated by the magnetic field of the coil is just sufficient to press the armature against the fixed magnetic parts. This makes energy consumption advantageous minimized. This also makes the use of the contactor more economical.
• the current setpoint generator advantageously specifies a maximum holding current in order to close the switching magnet again with the greatest possible force. If it is determined by means of the sensors that the magnetic circuit is closed again, the current setpoint generator again specifies the smaller holding current. If it is found that the magnetic circuit is still not closed after a predetermined time, the holding phase is ended and the contactor is opened or the switch-off process is initiated.
• the electronic switching magnet control has a data and / or control bus and communicates with other electronic devices via it.
• the switching magnet control itself can also be controlled by means of the data and / or control bus. It is also conceivable that other electronic devices are controlled by the solenoid control via the data and / or control bus.
• Figure 1 A mechanical representation of an electronically controlled contactor
• FIG. 2 an electronically controlled contactor with closed contacts
• Figure 2b an electronically controlled contactor, the switching magnet was slightly opened by external influences
• FIG. 3 a path-time diagram to show a normal closing process and the subsequent holding phase
• FIG. 4 a path-time diagram to show two closing processes, the armature at A having a smaller moment of inertia than the armature at B;
• Figure 5 is a block diagram of the electronic Wegmagnet ⁇ control
• FIG. 6 a flow chart of a program wa for controlling the switching-on process of a controlled contactor according to FIG. 1.
• FIG. 1 shows an electronically controlled contactor 2 with which at least one phase 15 of a circuit can be interrupted or closed.
• the switching contact 5 of the contactor 2 is in the open position, ie the current path 15 is interrupted.
• the switching contact 5 acted upon by a contact spring 5a is loosely connected to an armature 4 which can be moved by means of a coil 7.
• a current I By applying a voltage U le to the connecting wires 7a of the coil 7, a current I, st flows in the coil 7, which current generates a magnetic field which pulls the armature 4 into the coil 7.
• the current I actual is determined by means of the ammeter 6 and transmitted to the switching magnet control, not shown.
• the armature 4 of the contactor 2 covers the stroke distance H between the ON position (FIG.
• the anchor 4 has a mark 4a, which by means of Sensors S, 3a is detected as soon as the marking 4a passes the sensor S, 3a.
• the sensors S, 3a can be light barriers, with exactly one light source 3a being arranged opposite each photodetector S.
• the marking 4a can be a recess or bore, so that the light from a light source 3a is detected by the associated photodetector S as soon as the marking 4a of the armature 4 is exactly between the light source 3a and the associated sensor S.
• the photodetectors S and the light sources 3a are connected by means of the feed lines 3b, 3c to the switching magnet control, not shown.
• the displacement sensor 3 consists of n equal to seven light barriers with the sensors S t to S 7 .
• marking 4a of armature 4 will first pass sensor S 1 . Shortly before the marking 4a has passed the last sensor S 7 , the switching contact 5 closes. The armature 4 is then moved by the remaining armature stroke until the marking 4a has also passed the last sensor S 7 . At this moment the armature 4 closes the magnetic circuit.
• FIG. 3 shows in connection with FIG. 5 a time diagram to show a normal closing process and the subsequent holding phase.
• the upper diagram shows a path-time diagram for the position of the marking 4a or the armature 4.
• the switch-on process is started at time T equal to zero.
• a setpoint current I SoU is specified by means of the current setpoint generator 8.
• the current profile of the target current I SoU is an exponential function, the target current I SoU rising from zero towards a final value l m ⁇ .
• the armature 4 is accelerated by the magnetic field of the coil 7, the marking 4a of the armature 4 moving in the direction of the first sensor S.
• the switching magnet control specifies the target current I target 1 associated with the sensor S by means of the current setpoint generator 8.
• the voltage divider 9 specifies a new voltage such that an actual current I actual is set in the coil 7, which is equal to the target current I target 1 .
• the armature 4 with the switch contacts 5 attached to it is accelerated further in the direction of the ON position, as a result of which the mark 4a is detected by a second sensor S 2 after a time T 2 .
• a new set current I set 2 is specified again by means of the current setpoint generator 8. This process is repeated for each sensor S ( .
• the current setpoint generator 8 specifies a setpoint current I set 9 or I SoU 8 .
• This maximum possible current is calculated in such a way that it can also be predetermined or regulated by means of the voltage regulator 9 when the supply voltage of the solenoid control 1 corresponds only to approximately 75% of the normal supply voltage I SoU 9 is from time T 9 for a certain Time specified, so that it is always ensured that the switching magnet is firmly closed and the armature 4 no longer bounces.
• the switching magnet control switches to the holding phase, a current 1 holding being specified by means of the current setpoint generator 8, which is dimensioned such that the switching magnet just remains closed and the magnetic circuit is not opened even with normal vibrations . If the switching contacts 5 are deflected due to excessive vibrations, the armature 4 is also moved, the marking 4a being detected first by the last sensor S 9 . If this happens during the holding phase, as in 22 of FIG. 3, from time T 10 at which sensor S 9 detects the marking, the maximum possible target current I ma ⁇ is specified until sensor S 9 detects marking 4a no longer detected. However, it is also possible for the maximum set current I ma ⁇ to be predetermined for a certain time from the time T n , so that it is also ensured, as in the switch-on process, that the switch contacts 5 no longer bounce.
• FIG. 4 show two possible acceleration processes A and B of the armature 4.
• each sensor S only a fixed target current I SoU . assigned, so with an intelligent switching magnet control according to FIG. 4, a sensor S - a plurality of target currents I SoU . , assigned. It depends on the time elapsed until detection by the sensor S f which target current I target . , is specified.
• the armature 4 and the parts of the contactor 2 to be accelerated by it have a smaller inertia in comparison to B, whereby the armature 4 is accelerated faster with the same initial predetermined target current I. u and accordingly also the marking from the first sensor S 1 is detected than in B.
• the slower acceleration of the armature 4 at B can also result from the armature 4 being stuck or from the contactor being in an unfavorable installation position for switching on. Passes up if more time is to be detected, this means that the armature 4 is sluggish or sluggish and is more difficult to accelerate.
• a larger acceleration force must be generated by means of the coil magnetic field. This means that the coil current must be increased accordingly. Since the time elapsed until detection is a measure of the inertia, a larger target current I target , is given in accordance with the past time.
• FIG. 5 shows a block diagram of an intelligent switching solenoid control 1 in which the target currents I SoU; , depend on the time elapsed until the associated sensor S 1 is detected.
• the solenoid control 1 has a control block 17.
• the switch-on or switch-off process can be initiated by means of conventional input means 13. It is also advantageous if the solenoid control 1 has an auxiliary power supply 16 and the control is carried out via a bus control signal. From the supply voltage U v supplied by the control block 17, the coil voltage U s le lying on the coil 7 is adjusted by means of the voltage regulator 9 as a function of the difference between I, st and I Soll .
• the timer 10 is controlled, ie reset and / or started, by means of the control block 17 and the displacement sensor 3.
• the current setpoints ISoll, i t j are advantageously stored in a non-volatile memory 11 and are read out accordingly and fed to the comparator 20.
• the actual current I of the coil 7 is determined by means of the ammeter 6 and is likewise fed to the comparator 20. Both the actual current I actual and the signals from the displacement sensor 3 and the contact system, consisting, among other things, of the switching contacts 5, are fed to the message block 19.
• the message block 19 communicates with other electronic devices, not shown, by means of a data and / or control bus 12.
• the Switching solenoid control 1 has a control circuit 18, by means of which the contactor is switched off.
• FIG. 6 shows a flow chart for the switching magnet control 1 according to the invention.
• the program sequence shown is the same for the normal and intelligent switching magnet control 1.
• normal switching magnet control 1 only one target current I target is assigned to each sensor S, these being predetermined in each case in step S2 by means of the current target value transmitter 8.
• ⁇ to specify which of the time duration or the time interval ⁇ ; , depends on the detection of the associated sensor S ⁇ (intelligent switching magnet control).
• a start signal starts the switch-on process. This can be done by the supply voltage exceeding a certain voltage level. The voltage level is dimensioned so that the voltage is sufficient to regulate all current setpoints.
• step S2 the target current I SoU 1 or I target 1 ⁇ is specified after detecting the first sensor SI. Simultaneously or immediately thereafter, the timer 10 is reset and restarted in step S3. After step S3, the loop S4, S5 is run through until the next sensor S k + 1 has detected the marking 4a (step S5) or has exceeded the time t (k) associated with sensor S k (step S4). If this time t (k) is exceeded, the program branches to an emergency aid program to step S8. In step S8, a higher nominal current value I SoU than the nominal current I nominal k is specified in order to accelerate the armature with the maximum possible force. After step S8, it may be expedient to reset and start the timer 10 again.
• step S9 a loop consisting of steps S9 and S10 is run through again until the next sensor S k + 1 has detected the marking 4a (step S10) or the time t a measured by means of the timer 10 for the respective sensor S k proper time t (k) has exceeded (step S9). If the maximum time is exceeded during the emergency aid program (steps S8, S9, S10, SI1), the abort or switch-off process is initiated with step SI1 and a corresponding message is sent to other electronic devices by means of the data and / or control signal Components sent out. However, if the next sensor S k + 1 detects the marking 4a (step S10), the system branches back to the switch-on program and step S6 is carried out.
• step S6 If the last sensor S n has detected the marking, the switch-on process is completed and the holding phase is initiated with step S7, ie the holding current I hold is specified until the switch-off process is initiated. If, on the other hand, it is determined in step S6 that the marking 4a has not yet passed the last sensor, a branch is made to step S2 and a new target current I target k + 1 is specified.

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• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Control Of Linear Motors (AREA)
• Relay Circuits (AREA)
• Keying Circuit Devices (AREA)

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• 1996
  • 1996-02-06 DE DE19605974A patent/DE19605974A1/de not_active Withdrawn
• 1997
  • 1997-01-09 WO PCT/EP1997/000052 patent/WO1997029501A1/fr active IP Right Grant
  • 1997-01-09 DE DE59701402T patent/DE59701402D1/de not_active Expired - Fee Related
  • 1997-01-09 EP EP97900969A patent/EP0879474B1/fr not_active Expired - Lifetime
  • 1997-01-09 AT AT97900969T patent/ATE191583T1/de active

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