RU2344532C2 - Microprocessor protection system - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: microprocessor protection system comprises recorders, controlled power supply units connected to other elements of the microprocessor protection system according to the patent claim.

EFFECT: increasing accuracy of sensor input signal measurements and reliability of device operation.

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Description

The invention relates to electrical engineering and can be used in the technology of relay protection of objects with electric loads, for example, single-phase and three-phase motors.

A known motor protection system (Patent No. 2192699, IPC 7 Н02Н 7/08. Device for protecting an electric motor. Stepanov V.I., Stepanov V.A. BI No. 35 of November 10, 2002), containing current transformers for connection to different the power supply phases of the electric motor, a rectifier, an overload control unit, a time-current characteristic generating unit and executive relays, the overload control unit being made on discrete radio components. The disadvantage of this system is reduced automation conditions, and its reliability decreases with increasing time of continuous operation.

Also known microprocessor protection system (Chernobrov NN, Semenov VA Relay protection of energy systems, 1998. - 776 p.), Containing blocks of intermediate transformers and frequency filters, analog-to-digital converter and microprocessor control system.

The disadvantage of this system is the large overall dimensions, low reliability and limited functionality that determine their use only in stationary operating conditions.

The closest in technical essence to the invention is a microprocessor protection system (Patent No. 2222083, IPC 7 Н02Н 7/26, G01R 23/165, G01L 31/08. BI No. 27 of 09/20/2001), containing galvanic isolation blocks (blocks sensors) and preliminary scaling (scaling blocks) of input signals in the form of current and voltage, a block of frequency filters (signal normalization block), a signal generator for monitoring and diagnostics, an analog-to-digital converter, and a microprocessor control system for output relays and signaling in accordance with protection algorithms, and the groups of outputs of the galvanic isolation units and preliminary scaling of the input signals in the form of current and voltage are connected respectively to the first and second groups of inputs of the frequency filter unit, the group of outputs of which is connected to the group of inputs of an analog-to-digital converter, the group of inputs and outputs of which are connected to the first group of inputs and outputs of the microprocessor control system of output relays and alarm in accordance with protection algorithms, and the group of inputs of the shaper with control and diagnostic signals are connected to the group of outputs of the analog-to-digital converter, the first group of outputs of the control and diagnostic signal generator is connected to the second group of inputs of the galvanic isolation unit and preliminary scaling of the input signals in the form of current, the second group of outputs of the control and diagnostic signal generator is connected to the second group the inputs of the galvanic isolation unit and preliminary scaling of the input signals in the form of voltage, and the groups of inputs and outputs of the micro otsessornoy control system associated with a personal computer (recorder).

The low accuracy of the formation of sensor signals by such a device is due to the large nonlinearity of the converter circuits. The presence of a large number of functional blocks of the device leads to an increase in its energy consumption in violation of the implementation of the principle of autonomy, as well as to a decrease in the reliability of operation. In addition, this device does not meet the reliability conditions in a round-the-clock operation mode due to failures of composite converter blocks, i.e. due to the lack of diagnostics of the state of the converter blocks of the device.

In the direction of the implementation of this technical solution, the authors are aware of diagnostic devices for communication equipment blocks based on the principles of test and functional control (B. Shlyapobersky. Fundamentals of discrete message transmission technology. - M.: Radio and Communications, 1973. - 327 pp.). Applicable to the claimed object, the test control is partially performed in accordance with the algorithm of functioning of the MPSU. Using the principle of functional control of the device equipment significantly increases its overall dimensions, leading to a decrease in the reliability of the operation of the claimed facility.

The objective of the invention is to improve the accuracy of measurements of input sensor signals and the reliability of the device.

The task is achieved by the fact that in the well-known microprocessor-based protection system containing sensor blocks, power supplies, a recorder, a conversion channel, including a signal scaling unit, a signal normalization unit, a signal generator for monitoring and diagnostics, an analog-to-digital converter and a microprocessor control system (MPSU) output relays and alarm in accordance with the protection algorithm, the first group of inputs / outputs of which is a group of inputs / outputs of the recorder, and the second group is controlling by the outputs of the protection and signaling facility, redundant conversion channels, recorders and controllable power supplies are additionally introduced, the outputs of the sensor block are connected in parallel to the inputs of the main and backup conversion channels, which are inputs of the corresponding switch blocks, in each of the conversion channels of the group of information signal outputs from the outputs of the blocks the switches are connected through the appropriate scaling units to the conclusions of the group of information inputs of the microprocessor control system , the third groups of inputs and outputs of which are connected to the terminals of the corresponding controlled power supplies, and the fourth groups of inputs and outputs - of the main and standby MPSU are interconnected, in every conversion channel every fifth single-bit output of the MPSU is connected to the input of the corresponding block of switches, and the sixth single-bit outputs the primary and backup MPSU are connected to the inputs of the switch blocks in the corresponding backup and primary conversion channels, the seventh one-bit output of the primary MPSU is connected to the input of the reserve Nogo-managed storage unit, one-bit eighth backup MPSU output connected to the input ground of the storage unit managed.

In addition, each controllable power supply unit contains an unstabilized power supply unit, the output of which is connected to a normalizing amplifier for processing signals of the consumed currents of the equipment through a signal generator for monitoring and diagnostics, the other output of which is connected to a voltage regulator, and the controlled output of the input key of the unstabilized power supply unit is connected to a single the output of the MPSU, and the output key through the logical element And - with single-bit outputs of the main and backup MPSU.

In addition, the driver of control and diagnostic signals is made in the form of an electronic fuse.

A comparative analysis of the invention with the prototype shows that the proposed device differs from the known one by the introduction of the main and backup conversion channels, as well as registrars and controlled power supplies, which allows to obtain new properties regardless of the accuracy of measurements of the input signals of the sensors and thereby improve the accuracy of measurements. In addition, new functional relationships provide increased reliability of both the load control system and the device hardware paths, which allows us to conclude that the proposed device is significantly different.

Thus, the claimed object meets the criterion of "novelty." The applicant is not aware of technical solutions containing similar features that distinguish the claimed solution from the prototype, which allows us to conclude that the proposed solution meets the criterion of "inventive step".

The invention is illustrated by drawings.

Figure 1 shows the structural diagram of the device.

Figure 2 presents the block diagram of the switching and scaling of the sensor signals in the main conversion channel.

Figure 3 shows a structural diagram of a microprocessor control system.

Figure 4 shows a block diagram of a controlled power supply.

Figure 1 marked:

1 - sensor block; 2 - the main channel of conversion; 3 - backup conversion channel; 4 - main registrar; 5 - backup registrar; 6 - main controlled power supply; 7 - redundant managed power supply; the main channel of the conversion 2 includes a block of switches 8, a scaling unit 9 and MPSU 10; redundant conversion channel 3 includes a block of switches 11, a scaling unit 12, and the MPSU 13;

14 - the first group of inputs and outputs of the main MPSU for communication with the main registrar; 15 - the second group of outputs of the main MPSU for object management; 16 - the third group of inputs and outputs of the main MPSU for communication with the main controlled power supply; 17 - the fourth group of inputs and outputs of the main MPSU for communication with the backup MPSU; 18 - fifth single-bit output of the main MPSU for communication with the main block of switches; 19 - the sixth one-bit output of the main MPSU for communication with the backup block of switches; 20 - seventh one-bit output of the main MPSU for communication with a redundant controllable power supply; 21 - the first group of inputs and outputs of the backup MPSU for communication with the backup registrar; 22 - the second group of outputs of the backup MPSU for object management; 23 - the third group of inputs and outputs of the standby MPSU for communication with the standby controllable power supply unit; 24 - fifth single-bit output of the standby MPSU for communication with the standby unit of switches; 25 - the sixth single-bit output of the backup MPSU for communication with the main block of switches; 26 - the seventh single-bit output of the backup MPSU for communication with the main controlled power supply.

Figure 2 marked:

T1 - transformer winding of the sensor at a single-phase control object; 8 - one decade of the main block of switches, consisting of a two-input logic element And (IC type 564 LA7) and key S (IC type 590 KN13); 9 - one decade of the scaling unit, consisting of an operational amplifier 27, a resistor R, a diode VD, a transistor VT, and a capacitor C; 10 - the main MPSU; 11 - backup block of switches; 13 - reserve MPSU; 25 - the sixth single-bit output of the backup MPSU for communication with the main block of switches; U _x - bus information signals.

Figure 3 marked:

28 - the first port for inputting information signals; 29 - multiplexer; 30 - analog-to-digital Converter; 31 - buffer registers; 32 - bus formers; 33 - the second port of input-output data; 34 - RAM; 35 - flash ROM; 36 - timer; 37 - microprocessor; 38 - block manual installation; 39 - communication driver with a PC; U _x - bus information signals.

In figure 4 are indicated:

40 - power supply unit hardware path; 41 - driver of control and diagnostic signals; 42 - normalizing amplifier; 43 - voltage stabilizer; moreover, the power supply 40 consists of input S1 and output S2 keys, charger 44 and batteries A; the control and diagnostic signal generator 41 consists of a control transistor VT, an LED VD, a thyristor VD and resistors R1, R2 and R3; the normalizing amplifier 42 consists of resistors R4, R5 and an operational amplifier 45.

The sensor unit 1 (see Fig. 1) is designed to convert the magnitude of the variable ~ I _x load current of the control object into the corresponding value of the alternating voltage of the signal ~ U _x . In this case, the bit outputs of the sensor unit 1 are connected in parallel to the inputs of the main 2 and backup 3 conversion channels. The main 2 and redundant 3 conversion channels contain the same composition of blocks to perform the same functions. Their main purpose is to prevent emergencies in the event of failure of one of their elements, increase the service life of the device, ease of use (timely replacement of device blocks implemented in a modular structure) and increase the reliability of operation during round-the-clock operation of the facility. Therefore, the main and reserve registrars 4 and 5, as well as the controlled power supplies 6 and 7, are additionally introduced into the device.

As registrars 4 and 5, liquid crystal modules were used to visualize current information, as well as parallel connection of portable PCs. Managed power supplies 6 and 7 perform the power supply of the hardware path in the allotted time of the round-the-clock operation of the facility.

The inputs of the main conversion channel 2 are the inputs of the switch unit 8, the outputs of which through the information bus of the AC voltage signals ~ U _x are connected to the inputs of the scaling unit 9, made in the form of an amplitude detector. The outputs of the scaling unit 9 are connected through the information bus of the signals U _x to the input of the first port of the MPSU 10. Similarly, the inputs of the backup conversion channel 3 are the inputs of the block of switches 11, the outputs of which through the information bus of the AC voltage signals ~ U _x are connected to the inputs of the scaling unit 12, made in the form of an amplitude detector. The outputs of the scaling unit 12 are connected via the information bus U _x with the input of the first port of the MPU 13.

The main recorder 4 is connected to the MPSU 10 through the first group of inputs and outputs 14, the second group of outputs 15 of the main MPSU communicates with the object in accordance with the developed protection algorithm, the third group of inputs and outputs 16 connects the main MPSU 10 with the main controlled power supply 6, the main MPSU 10 is connected to the backup MPSU 17 through the fourth group of inputs and outputs, the fifth single-bit output 18 of the main MPSU is connected to the main block of switches 8, its sixth single-bit output 19 is connected to the backup block of switches 11, and the seventh one-bit the nuclear output 20 is with the input of the backup controllable power supply 7. In this case, the backup recorder 5 is connected to the backup MPPS 13 through the first group of inputs and outputs 21, the second group of outputs 22 of the backup MPPS 13 implements communication with the object in accordance with the developed protection algorithm, the third group I / O 23 connects the backup MPSU 13 with the backup managed power supply 7, the fifth single-bit output 24 of the backup MPSU 13 is connected to the backup block of switches 11, the sixth single-bit output 25 of the backup MPSU 13 is connected to the main switching unit Ators 8, the seventh single-bit output 26 of the standby MPSU 13 is connected to the main controlled power supply 6.

The number of sensors in block 1 (see figure 2) is selected depending on the number of phases of supply voltages used at the facility. For a single-phase load, it is envisaged to place the power wire through the inner cross section of a round (for example, ferrite or alsifer for high-frequency supply voltages or steel for low-frequency circuits) or a rectangular core ring. In this case, the primary winding of the current transformer is the half-loop of the supply wire, and the wound winding (about 100 turns) on the core ring is the output winding of the sensor unit 1. Therefore, one terminal of the secondary winding of the transformer is connected to the zero bus, and the other to the inputs of the main 2 and backup 3 conversion channels, which are the inputs of the blocks of the switches 8 and 11, respectively. In the case of a three-phase load, the use of three sensors of the same type 1 is provided for each phase of the power supply of the facility. For three-phase circuits, standard Microchip 60 × (601, 602, 603 or 604) type sensors can be used. Moreover, the number of supply phases is not regulated in case of multiphase loads.

MPSU 10 and 13 are designed to convert the analog signals of sensors 1 into digital form for the purpose of their further processing and development of control actions on the object, as well as the ability to switch from the main conversion channel 2 to the backup 3. The functional blocks of the main 10 and backup 13 of the MPSU correspond (see Fig. 3) a circuit of a commercially available microcontroller MSP430F169 from Texas Instruments. The structure of this controller is additionally included a communication driver with a PC 39.

Managed power supplies 6 and 7 are made (see figure 4) based on the same functional blocks. By the example of a controlled power supply circuit 6 of the main conversion channel 2, the relationship of the composite power supply units 40 through the driver of diagnostics and diagnostics 41 with the inputs of the normalizing amplifier 42 and voltage regulator 43 is established. The power supply unit 40 consists of a charger 44, at the input of which the first key S1 is controlled by the main MPSU 10, and at the output the second key S2 with the output of the battery A (≈12 V) - the main 10 and the backup 13 MPSU through the logical element I.

The normally-closed contact of the output key S2 of the power supply 40 is connected to the input of the monitor and diagnostics signal generator 41, made in the form of an electronic fuse 41. The essence of its operation is to generate alarms for switching from one conversion channel to another. This is achieved by continuously monitoring the current consumption of the instrument path through the normalizing amplifier 42 and voltage regulator 43. As a voltage stabilizer 43, IC 142EN5 is used to generate the output voltage U _o = + 6.6 V. This voltage is supplied to the output balancing stage with artificial zero by bus. Therefore, at the outputs of the voltage stabilizer 43, output voltages U _1,2 = ± 3,3 V.

The calibration node of the primary signal conversion from the control object is carried out (see figure 2) as a result of the selection of critical values of the load resistances. Moreover, the minimum value of the motor load is set to its operating mode in an unloaded state with a consumption current in one of the phases (for example, A) of I _pmin = 1 A. The maximum loaded state of the motor is set to a current of consumption of one of the phases with I _p.max = 100 A. In this case, the minimum loaded state of the engine corresponds to the amplitude of the voltages from the output of the sensor 1 value U _min = 0.1 V, and the maximum loaded - U _max = 2.1 V. Changing the zero bias voltage in the operational amplifier 27 of the scaling unit 9 the range of the analogous detected value from 0.1 V to 2.1 V is selected. The choice of the lower threshold value of 0.1 V is due to the need for additional control of the reduced supply voltage of the object, for example, as a result of phase imbalance.

The calibration of the normalizing amplifier 42 (see figure 4) in a controlled power supply 6 (or 7) is implemented in two boundary values of the current consumption of the device. The lower value corresponds to the magnitude of the rated current consumption _n.pot I = 10 mA when the output voltage U _O ≈11 The output of the electronic fuse corresponding to the nominal current consumption of one channel conversion 2 or 3. In this case, the output of the operational amplifier 45 of the normalizing amplifier 42 is generated polar _n.min voltage U = 0.1 V upper limit value of consumption current I = 30 mA _v.maks output from the electronic fuse 41 corresponds to the output voltage value of the normalizing amplifier 42 U _{V.Mau c} = 1.1 V obtained when the additional block of a tuning shunt ballast resistor voltage input terminals 43 of the stabilizer.

After programming MPSU 10 and 13 is completed (see Fig. 1), the device is debugged in the complex of the main 2 and backup 3 conversion channels when the sensor signals 1 are simulated by the voltage amplitude in the middle of the range with a voltage of 0.5 V. The essence of debugging is reduced to switching of functional blocks of the main 2 and backup 3 channels of conversion after 12 hours of continuous operation.

The principle of operation of the device is as follows. When the control object is operating, the sensor unit 1 continuously generates an amplitude signal with a frequency of the supply voltage. In the initial start-up of the device, the main conversion channel 2 is connected (see Fig. 1) and the functional blocks of the backup conversion channel 3 are turned off. In this case, the MPSU 10 disconnects the MPSU 13 and the controlled power supply 7 in the backup conversion channel via buses 17 and 20.

In the nominal mode of operation of the motor from the outputs of the current transformers of the sensor unit 1 (see Fig. 2), varying voltage amplitudes are generated in the operating range, which are fed to the inputs of the main conversion channel 2, which are the terminals of the S keys of the key block 8. These keys are in normal closed state, as MPSU 10 generates a constant resolution signal on bus 18 through element I. Normally closed contacts of keys S of key block 8 supply a varying amplitude voltage to the input of the scaling block, which is the input of amplitude detector 27. Therefore, the deviation of the voltage amplitudes of the sensors 1 is converted to a variable polar voltage. Such an analog signal is fed to the input-output port 28 of the MPSU 10.

In accordance with the conversion algorithm in MPSU 10 (see Fig. 3), the initial analog signal is supplied from port 28 through the multiplexer 29 to the input of the analog-to-digital converter 30, from where it is digitally recorded in register 31 for subsequent processing in microprocessor 37. Microprocessor 37 generates digital signals in the address and data buses through the second input-output port 33 for the functioning of the communication driver 39 with the PC 4.

At the end of the operating time (every 12 hours) of the main functional blocks of the device, the microprocessor 37 generates through port 33 and bus 20 a permission signal to turn on the backup controlled power supply 7, which feeds the hardware paths of switching blocks 11, scaling 12, and MPSU in the backup conversion channel 13. In accordance with the conversion algorithm, the MPSU 10 first transfers the conversion functions of the MPSU 13, and then connects the backup unit of the switches 11. In the subsequent time cycle, the MPSU 13 turns off the main block of switches 8 and a controlled power supply. The operation mode of the backup conversion channel 3 is similar to the above operation mode of the main channel 2 and is distinguished by the visualization of data on the connected backup recorder 5.

In the critical mode of operation of the device, the emergency and emergency conditions of the object are distinguished. The pre-emergency state corresponds to the values of the polar signals of sensors of the order of 2.1 V to 2.11 V, and the emergency state corresponds to 2.1 V and higher. In the latter case, the MPPS 13 on the bus 22 generates a shutdown signal of the object. Signals of the emergency condition are recorded in the recorder 5 with the aim of preliminary notification of maintenance personnel.

The implementation of functional control and switching of the main controlled power supply 6 is implemented similarly to block 7 (see figure 4). In the normal operating mode, the primary connection of block 6 corresponds to the connection in the power supply 40 of the charger 44 to the mains voltage through a normally-closed key S1, as well as the inclusion of the output voltage by the signal of the element And through the key S2 to the input of the electronic fuse 41. In this case, the pre-emergency state of the device equipment It corresponds to the consumption current values of magnitude 2 × I _n.pot ≈25 mA, crash - 30 mA and above, the output voltages corresponding to the normalizing amplifier 42 in the values 1.1 and 1.11 in the B ootvetstvenno. In the latter case, the MPSU 10 generates a signal to the enable input of the standby controllable power supply unit 7 via the bus 20, and the MPSU 13 is turned on via the bus 17. In the same way, the equipment is switched from the main 2 to the backup 3 conversion channels. The signals of the pre-emergency state of the functional control of the equipment paths are recorded in the recorder 5 for the purpose of preliminary notification of the maintenance personnel.

Thus, the application of the proposed device provides control of the round-the-clock mode of operation of the control object. The technical and economic advantages of the invention are to increase the accuracy of measurements of input sensor signals, the reliability of the device and the reliability of operation at the control object.

Claims (3)

1. A microprocessor-based protection system containing sensor blocks, power supplies, a recorder, a conversion channel, including a signal scaling unit, a signal generator for monitoring and diagnostics, an analog-to-digital converter, and a microprocessor control system (MPSU) for output relays and signaling in accordance with the protection algorithm, the first group of inputs and outputs of which is the group of inputs and outputs of the recorder, and the second group is the control outputs of the object of protection and alarm, characterized in that it will complement redundant conversion channels, registrars and controlled power supplies have been introduced, the outputs of the sensor unit are connected in parallel to the inputs of the main and backup conversion channels, which are inputs of the corresponding switch units, in each of the conversion channels, the groups of information signal outputs from the outputs of the switch units are connected through the corresponding scaling units to the conclusions of the group of information inputs of the microprocessor control system, the third group of inputs and outputs of which are connected to the outputs of the corresponding controlled power supplies, and the fourth groups of inputs and outputs of the main and standby MPSU are interconnected, in each conversion channel, every fifth single-bit output of the MPSU is connected to the input of the corresponding block of switches, and the sixth single-bit outputs of the main and standby MPSU are connected to the inputs of the switch blocks in the corresponding backup and main conversion channels, the seventh one-bit output of the main MPSU is connected to the input of the backup controllable memory unit, the seventh one-bit The output output of the backup MPSU is connected to the input of the main managed memory unit. 2. The microprocessor-based protection system according to claim 1, characterized in that each controlled power supply unit contains an unstabilized power supply unit, the output of which is connected to a normalizing amplifier for processing signals of the consumed currents of the equipment through a signal generator for monitoring and diagnostics, the other output of which is connected to a voltage regulator, moreover, the controlled output of the input key of the unstabilized power supply is connected to the single-bit output of the MPSU, and the output key through the logical element And to the single-bit outputs of the ovnogo and reserve MPSU. 3. The microprocessor protection system according to claim 2, characterized in that the shaper of control and diagnostic signals is made in the form of an electronic fuse.

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