DE202016107108U1 - Device for the safety-relevant disconnection of the current of a power controller having a power controller via a thyristor - Google Patents

Abstract

Apparatus for the safety-relevant disconnection of the current of an electric load powered by a power controller, comprising - a three-phase network (15), a power controller (18) having at least one antiparallel thyristor pair (12, 13, 14) connected to the three-phase network, one of the antiparallel Thyristor is a current to the load-conducting thyristor (a) and the other is a current from the load dissipating thyristor (b), and - one connected to the outputs of the power controller (18) load (16), - wherein to control the thyristors of the power controller (18) a controller (2), a first shutdown signal generator (4) and a second shutdown signal generator (5) are provided, - the controller (2) for receiving a first shutdown command (SPO1) and a second shutdown command (SPO2) and for providing Ignition pulses (Z1, ..., Z6) is designed for the thyristors of the power controller, - the first switch-off signal generator (4) for the reception of the first switch-off command (SPO1) and for the provision of a first switch-off signal (A1) for the current from the load dissipating thyristors of the power controller, - the second switch-off signal generator for receiving the second switch-off command (SPO2) and for providing a second switch-off signal (A2 ) is formed for the current to the load-conducting thyristors of the power controller, - the thyristor associated shutdown signal and the same thyristor associated, issued by the controller (2) firing pulses each an AND gate (6, 7, 8, 9, 10, 11 ) are fed, at the output of a control signal for the respective thyristor can be output, and - the first shutdown signal generator (4) after receiving the first shutdown command (SPO1) the shutdown signal (A1) for the current from the load dissipating thyristors to the these thyristors AND gates (6, 7, 8) outputs to block them, - the second Abschaltsignalgene Rator (5) after receiving the second shutdown command (SPO2) the shutdown signal (A2) for the current to the load-conducting thyristors to the these thyristors associated AND gates (9, 10, 11) outputs to lock them, and - the controller (2) adjusts the output of firing pulses for the thyristors upon receipt of the first and / or second shutdown commands.

Description

Technical area

The invention relates to a device for safety-relevant shutdown of the current of a thyristor having power controller powered load.

background

It is already known that certain procedures must be followed in order to safely shut down a rotating machine in the sense of EU-issued machinery guidelines. For example, as part of the development of a machine, a risk analysis is necessary in which the risk that emanates from the machine is estimated. This risk analysis identifies which safety category or performance level (PL) is necessary for the machine so as not to jeopardize a machine operator. On the other hand one can determine by different methods which performance level a machine has. As long as the performance level of the machine is lower than the performance level required for the machine, a rework is necessary to reduce the risk posed by the machine. In this context, various standards have been published in recent years in which a certification process is defined. These standards include in particular the EN 61800-5-2 or the IEC 62061 and the ISO 13849-1 , These standards concern the area of functional safety of a machine. In particular, these standards also describe the safety function "Safe Torque Off" (STO). If required, this safety function ensures safe shutdown of the machine by switching the machine off without torque.

In the EP 2 899 872 A1 a DC drive power supply system is described which is intended to continuously provide values of DC-drive current in operation on the output side.

The supply system comprises a converter formed by a B6 bridge circuit with 6 semiconductor switches for at least one direction-dependent two-quadrant operation, at least one associated pulse-based drive device, an input-side and an output-side connection for the power converter and at least one mechanical interruption device for the input and / or output side connection. If an STO signal is received, then a direct change of the converter operation is carried out in an inverter limit. Then, after the lapse of a first time interval beginning with the receipt of the STO signal, an interruption of supply of drive energy by the drive device to the power converter and an interruption signal to the at least one mechanical interrupt device occur just in case after expiration of a second subsequent time interval the current flowing on the output side has not decayed below a safety-critical limit value.

Summary

The object of the invention is to provide further uses for a safe shutdown.

• – einem Drehstromnetz,
• – einem an das Drehstromnetz angeschlossenen, mindestens ein antiparalleles Thyristorpaar aufweisenden Leistungssteller, wobei einer der antiparallelen Thyristoren ein Strom zur Last leitender Thyristor und der andere ein Strom von der Last ableitender Thyristor ist, und
• – einer an die Ausgänge des Leistungsstellers angeschlossenen Last,
• – wobei zur Steuerung der Thyristoren des Leistungsstellers eine Steuerung, ein erster Abschaltsignalgenerator und ein zweiter Abschaltsignalgenerator vorgesehen sind,
• – die Steuerung zum Empfang eines ersten Abschaltbefehls (SPO1) und eines zweiten Abschaltbefehls (SPO2) und zur Bereitstellung von Zündimpulsen für die Thyristoren des Leistungsstellers ausgebildet ist,
• – der erste Abschaltsignalgenerator zum Empfang des ersten Abschaltbefehls und zur Bereitstellung eines ersten Abschaltsignals für die Strom von der Last ableitenden Thyristoren des Leistungsstellers ausgebildet ist,
• – der zweite Abschaltsignalgenerator zum Empfang des zweiten Abschaltbefehls und zur Bereitstellung eines zweiten Abschaltsignals für die Strom zur Last leitenden Thyristoren des Leistungsstellers ausgebildet ist,
• – das einem Thyristor zugeordnete Abschaltsignal und die demselben Thyristor zugeordneten, von der Steuerung ausgegebenen Zündimpulse jeweils einem UND-Glied zuführbar sind, an dessen Ausgang ein Steuersignal für den jeweiligen Thyristor ausgebbar ist, und
• – der erste Abschaltsignalgenerator nach Empfang des ersten Abschaltbefehls das Abschaltsignal für die Strom von der Last ableitenden Thyristoren an die diesen Thyristoren zugeordneten UND-Glieder ausgibt, um diese zu sperren,
• – der zweite Abschaltsignalgenerator nach Empfang des zweiten Abschaltbefehls das Abschaltsignal für die Strom zur Last leitenden Thyristoren an die diesen Thyristoren zugeordneten UND-Glieder ausgibt, um diese zu sperren, und
• – die Steuerung nach Empfang des ersten und/oder des zweiten Abschaltbefehls die Ausgabe von Zündimpulsen für die Thyristoren einstellt.

This object is achieved by a device for safety-relevant disconnection of the current of a power supply via a power supply supplied electrical load, with

• A three-phase network,
• - One connected to the three-phase network, at least one antiparallel thyristor having power controller, one of the antiparallel thyristors is a current to the load-conducting thyristor and the other is a current from the load dissipating thyristor, and
• A load connected to the outputs of the power controller,
• Wherein a controller, a first shutdown signal generator and a second shutdown signal generator are provided for controlling the thyristors of the power controller,
• The control is designed to receive a first switch-off command (SPO1) and a second switch-off command (SPO2) and to provide ignition pulses for the thyristors of the power controller,
• The first switch-off signal generator is designed to receive the first switch-off command and to provide a first switch-off signal for the current from the load-dissipating thyristors of the power controller,
• The second switch-off signal generator is designed to receive the second switch-off command and to provide a second switch-off signal for the current to the load-conducting thyristors of the power controller,
• - The thyristor associated shutdown signal and the same thyristor associated, issued by the control firing pulses are each fed to an AND gate, at whose output a control signal for the respective thyristor can be output, and
• The first switch-off signal generator, after receiving the first switch-off command, outputs the switch-off signal for the current from the load-dissipating thyristors to the AND elements associated with these thyristors in order to block them;
• The second switch-off signal generator, after receiving the second switch-off command, outputs the switch-off signal for the current-carrying thyristors to the thyristors associated with these thyristors in order to block them, and
• - The controller after receiving the first and / or the second shutdown command sets the output of firing pulses for the thyristors.

By such a device, a safety function for electrical resistance loads is provided in an advantageous manner, which can be constructed in different load configurations and which are powered from a three-phase network via a power regulator having antiparallel connected thyristors.

This safety function advantageously ensures that, if necessary, it is reliably prevented that a further current flow into the load takes place. This in turn stops further heating of the load, which could possibly lead to their destruction.

Another advantage of the invention is that the desired safety-relevant shutdown of the current flowing in the load is ensured even if one of the two shutdown commands, since in this case one of the two thyristors of each thyristor pair is de-energized, because the respective other shutdown command either all the current to the load-conducting thyristors or all the current from the load-dissipating thyristors of the anti-parallel thyristor pairs and thus the entire antiparallel thyristor pair de-energized switches.

According to one embodiment, the power controller 3 may comprise thyristor pairs. This configuration advantageously makes it possible to supply a load with three-phase current, wherein each thyristor pair is assigned a phase current individually and each thyristor pair can be individually controlled.

According to another embodiment, the power controller 2 may comprise thyristor pairs. This advantageously makes it possible to supply a load with reduced thyristor control power in three phases.

The generation and output of the shutdown commands can be made in an advantageous manner by a higher-level control. This has the advantage that in the higher-level controller present information that make a shutdown of the current flowing to the electrical load current can be considered in the generation of the shutdown commands.

The higher level controller may be advantageously connected to the controller and configured to receive error indication signals from the controller and to generate the shutdown commands in response to receipt of the error indication signals received from the controller. This has the advantage that errors detected by or in the controller can also be taken into account when generating the shutdown commands.

Furthermore, the device may have a monitoring unit which is designed to measure the currents flowing at the outputs of the power controller and outputs a fault indication signal to the higher-level controller when the measured currents of respective setpoint values deviate. This has the advantage that the power supply of the load can be monitored and a safe shutdown of the load-supplying current can be initiated by outputting shutdown commands when an error occurs from the higher-level control. In particular, both during normal operation and after the power has been switched off by means of the monitoring unit, it is possible to check whether correct current values are present. In normal operation, currents flow through the two thyristors of a thyristor pair opposite direction, but matching current values. If, on the other hand, the difference between the measured current values is greater than a permissible difference, then there is an error. This is reported in the form of a suitable Fehlerhinweissignals from the monitoring unit to the higher-level control, which -if necessary- appropriate countermeasures in the way, in particular a provision of shutdown commands, due to which prevents an interruption of the control of the thyristors another current flow through the thyristors becomes.

Advantageously, the first shutdown signal generator may be connected to the second shutdown signal generator so that the two shutdown signal generators monitor each other. This also allows an error indication signal to be output to the higher-level controller.

The load is preferably an electrical resistance load having one of several possible predetermined load configurations. For example, the load has ohmic resistors which are interconnected in a star-shaped or triangular manner. An application of the invention can thus be made with different resistance configurations.

Advantageously, the load can be powered single or multi-phase power. Consequently, the invention can be used in many ways.

Brief description of the drawings

Further advantageous features of the invention will become apparent from the following exemplary explanation with reference to FIGS. It shows

1 1 is a block diagram of a device for safety-relevant disconnection of the current of a load supplied via a power controller,

2 a sketch of a first embodiment of a load configuration,

3 a sketch of a second embodiment of a load configuration,

4 a sketch of a third embodiment of a load configuration and

5 a sketch of a fourth embodiment of a load configuration.

Description of the embodiments

The 1 shows a block diagram of a device for safety-relevant shutdown of the current via a power controller 18 powered load 16 , this power controller 3 thyristor pairs 12 . 13 and 14 each of which includes 2 antiparallel connected thyristors a and b.

The illustrated device has a three-phase network 15 on, which provides at its output first current phase signals U1, V1 and W1. These are via the power controller 18 , at whose outputs second current phase signals U2, V2 and W2 are present, to a load 16 passed on to the power supply. At the load 16 it is an electrical load, in particular a resistance load. Alternatively, it may be at the load 16 also act to an inductances and / or capacitive load.

Subsequently, it is assumed that the load 16 is a resistance load and that this resistance load is a triangular-shaped resistors or star-shaped resistors.

The Indian 1 shown power controller 18 has 3 thyristor pairs 12 . 13 and 14 on. Each of these thyristor pairs has two antiparallel thyristors a and b, wherein thyristor a is a current to the load-conducting thyristor and the thyristor b is a current from the load dissipating thyristor in the respective thyristor. At the entrance of the thyristor pair 12 is the current phase signal U1. At the output of the thyristor pair 12 the current phase signal U2 is provided. At the entrance of the thyristor pair 13 is the current phase signal V1 on. At the output of the thyristor pair 13 the current phase signal V2 is provided. At the entrance of the thyristor pair 14 is the current phase signal W1 on. At the output of the thyristor pair 14 the current phase signal W2 is provided.

The control of the thyristors is controlled by a controller 2 performed in normal operation of the device ignition pulses Z1, Z2, Z3, Z4, Z5 and Z6 for the thyristors of the power controller 18 outputs.

Is due to a fault another power to the load 16 or another current flow to the load 16 be safely prevented then by a parent controller 1 Shutdown commands SPO1 and SPO2 to an input terminal 3 the device output and via this input terminal 3 to the controller 2 forwarded. Furthermore, the shutdown command SPO1 is also sent to a first shutdown signal generator 4 and the shutdown command SPO2 to a second shutdown signal generator 5 forwarded.

At the shutdown signal generators 4 and 5 it is hardware that is designed to convert the respectively delivered shutdown command into a shutdown signal or blocking signal for a downstream AND gate, so that this for by the controller 2 output ignition pulses is safely blocked. As a result, a further control of the thyristors is prevented, which in turn ensures that no further power supply to the load 16 takes place, ie that the current flow to the load 16 is switched off.

In particular, the shutdown signal generator 4 in response to receipt of the shutdown command SPO1, provide at its output a shutdown signal A1, each of which is an input terminal of the AND gates 6 . 7 and 8th is supplied. This will cause the AND gates 6 . 7 and 8th for possible ignition pulses at the other input terminal of the AND gate 6 . 7 and 8th impermeable. This causes the current from the load dissipating thyristors b of thyristor pairs 12 . 13 and 14 are no longer ignited, so that no further current flow through these thyristors b can take place.

Furthermore, the shutdown signal generator 5 in response to the receipt of the shutdown command SPO2 provide at its output a shutdown signal A2 available, each one input terminal of the AND gates 9 . 10 and 11 is supplied. This will cause the AND gates 9 . 10 and 11 for possible ignition pulses at the other input terminal of the AND elements 9 . 10 and 11 impermeable. This causes the current to the load-conducting thyristors a of the thyristor pairs 12 . 13 and 14 no longer be detonated. This ensures that no further current can flow through these thyristors a.

An advantage of in the 1 shown apparatus is that even if one of the shutdown SPO1 or SPO2 fails, a safe shutdown of the current flow is ensured by the thyristors to the load, since it is sufficient to interrupt this current flow when either the thyristor a or the thyristor b of the respective thyristor pair can not conduct electricity.

In addition to providing the shutdown signals A1 and A2 by the shutdown signal generators 4 and 5 also takes care of the control 2 for turning off the current flow through the thyristors by providing no further firing pulses at their outputs in response to the receipt of the shutdown commands SPO1 and / or SPO2 and using firmware. This occurs with a time delay to provide the shutdown signals A1 and A2.

To monitor the operation of the device is a monitoring unit 17 intended. This preferably leads both during normal operation of the device and after the output of the shutdown commands a measurement of the in the leads to the load 16 flowing currents I1, I2 and I3. In normal operation of the device, although the currents flowing through the thyristors a and b of a thyristor pair are oppositely directed, they have identical current values. This is detected by the monitoring unit, which then sends corresponding information to the higher-level control 1 outputs. On the other hand, if said current measurement indicates that the currents flowing through the thyristors a and b of one or more thyristor pairs each have different current values, for example due to a defect of one of the thyristors, then the monitoring unit recognizes 17 the presence of an error and sends an associated error indication signal F1 to the higher-level controller 1 , This in turn provides the abovementioned shutdown commands SPO1 and SPO2 available, by which - as described above - a safe shutdown of the further current flow through the thyristors to the load. This safely prevents overheating of the load.

In this fault state of the device, the measurement of the currents I1, I2 and I3 by means of the monitoring unit 17 continued. The measured current values must each be 0, since a current flow through the thyristors is interrupted. This is done by the monitoring unit 17 detected and to the higher-level control 1 reported.

Furthermore, it also takes place in the controller 2 an error monitoring. Detects the controller 2 for example, that there is a malfunction of the device, then gives the controller 2 an error indication signal F2 off, which the higher-level control 1 is communicated. This in turn initiates appropriate countermeasures, for example an output of the shutdown commands SPO1 and SPO2.

A further error monitoring takes place in that the shutdown signal generators 4 and 5 monitor each other. Detects, for example, the shutdown signal generator 4 after receiving the shutdown command SPO1, that of the shutdown signal generator 5 no shutdown command has been received, then he reports this to the parent control unit 1 , A safe shutdown of the by the power controller 18 to the load 16 However, flowing current is also ensured in this case, since this safe shutdown already by the output of the shutdown signal A1 to the respective first input terminal of the AND gates 6 . 7 and 8th is guaranteed.

The 2 shows a sketch of a first embodiment of a load circuit 16 , In this first embodiment, three ohmic resistors are interconnected in a triangular manner and the connection points of two resistors with a respectively associated terminal of a phase current at the output of the power controller 18 directly connected.

The 3 shows a sketch of a second embodiment of a load circuit 16 , In this second exemplary embodiment, three ohmic resistors are interconnected in a triangular manner and the connection points of two resistors are each connected via a transformer to a respectively associated terminal of a phase current at the output of the power controller 18 coupled.

The 4 shows a sketch of a third embodiment of a load circuit 16 , In this third embodiment, 3 ohmic resistors are connected in a star-shaped manner with one another, and the respective other terminal of the resistors is directly connected to a respectively associated connection a phase current at the output of the power controller 18 directly connected.

The 5 shows a sketch of a fourth embodiment of a load circuit 16 , In this fourth embodiment, 3 ohmic resistors are connected to each other in a star shape. The respective other connection of two of these resistors is directly connected to a respectively associated connection of a phase current at the output of the power controller 18 directly connected. The other terminal of the third resistor is connected directly to the output of the three-phase network to which the phase current W is provided. In this fourth embodiment, the power controller comprises 18 only 2 thyristor pairs, each having 2 antiparallel thyristors.

In the embodiments described above, the load 16 each controlled in three phases. Alternatively, it is also possible to control the load, for example, one or two-phase.

Furthermore, the load may also be an inductive load or a capacitive load.

LIST OF REFERENCE NUMBERS

1

Higher level control

2

control

3

input terminal

4

Abschaltsignalgenerator

5

Abschaltsignalgenerator

6

AND gate

7

AND gate

8th

AND gate

9

AND gate

10

AND gate

11

AND gate

12

First antiparallel thyristor pair

13

Second antiparallel thyristor pair

14

Third antiparallel thyristor pair

15

Three-phase system

16

load

17

monitoring unit

18

power controllers

a

Current to the load conducting thyristor

b

Current from the load dissipating thyristor

F1

Error indication signal

F2

Error indication signal

SPO1

 shutdown

SPO2

 shutdown

Z1

ignition pulse

Z2

ignition pulse

Z3

ignition pulse

Z4

ignition pulse

Z5

ignition pulse

Z6

ignition pulse

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

• EP 2899872 A1 [0003]

Cited non-patent literature

• EN 61800-5-2 [0002]
• IEC 62061 [0002]
• ISO 13849-1 [0002]

Claims (11)

Device for the safety-relevant disconnection of the current of an electric load powered by a power controller, comprising - a three-phase system ( 15 ), - one connected to the three-phase network, at least one antiparallel thyristor pair ( 12 . 13 . 14 ) power controller ( 18 ), wherein one of the anti-parallel thyristors is a current to the load-conducting thyristor (a) and the other is a current from the load dissipating thyristor (b), and - one to the outputs of the power controller ( 18 ) connected load ( 16 ), - wherein for controlling the thyristors of the power controller ( 18 ) a controller ( 2 ), a first shutdown signal generator ( 4 ) and a second shutdown signal generator ( 5 ), - the controller ( 2 ) for receiving a first switch-off command (SPO1) and a second switch-off command (SPO2) and for providing ignition pulses (Z1, ..., Z6) for the thyristors of the power controller, - the first switch-off signal generator ( 4 ) for receiving the first shutdown command (SPO1) and for providing a first shutdown signal (A1) for the current from the load dissipating thyristors of the power controller, - the second shutdown signal generator for receiving the second shutdown command (SPO2) and for providing a second shutdown signal ( A2) is designed for the current to the load-conducting thyristors of the power controller, - the thyristor associated shutdown signal and the same thyristor associated, from the controller ( 2 ) ignition pulses each an AND gate ( 6 . 7 . 8th . 9 . 10 . 11 ) can be fed, at whose output a control signal for the respective thyristor can be output, and - the first shutdown signal generator ( 4 ) after receiving the first switch-off command (SPO1), the switch-off signal (A1) for the current from the load-dissipating thyristors to the AND gates ( 6 . 7 . 8th ) to disable them, - the second shutdown signal generator ( 5 ) after receiving the second switch-off command (SPO2), the switch-off signal (A2) for the current to the load-conducting thyristors to the AND gates ( 9 . 10 . 11 ) to disable them, and - the controller ( 2 ) adjusts the output of firing pulses for the thyristors upon receipt of the first and / or second shutdown commands. Device according to claim 1, characterized in that the power controller ( 18 ) Has 3 thyristor pairs. Device according to claim 1, characterized in that the power controller ( 18 ) Has 2 thyristor pairs. Device according to one of the preceding claims, characterized in that the controller ( 2 ) adjusts the output of the firing pulses in time after the output of the shutdown signals (A1, A2). Device according to one of the preceding claims, characterized in that it has a higher-level control ( 1 ), which is designed to generate and output the shutdown commands (SPO1, SPO2). Apparatus according to claim 5, characterized in that the higher-level control ( 1 ) with the controller ( 2 ) and is adapted to provide error indication signals (F2) from the controller ( 2 ) and the shutdown commands (SPO1, SPO2) in response to the receipt of 2 ) to generate error indication signals (F2) received. Device according to claim 5 or 6, characterized in that it comprises a monitoring unit ( 17 ), which are used to measure at the outputs of the power controller ( 18 ) flowing currents (I1, I2, I3) is formed and in a deviation of the measured currents of respective setpoints a Fehlerhinweissignal (F1) to the higher-level control ( 1 ). Device according to one of the preceding claims, characterized in that the first shutdown signal generator ( 4 ) with the second shutdown signal generator ( 5 ) and the two shutdown signal generators monitor each other. Device according to one of the preceding claims, characterized in that the load is an electrical resistance load and has a predetermined load configuration. Apparatus according to claim 9, characterized in that the load comprises ohmic resistors which are interconnected in a star-shaped or triangular manner. Device according to one of the preceding claims, characterized in that it is designed for single or multi-phase control of the load.

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