RU116711U1 - MICROPROCESSOR SYSTEM OF RELAY PROTECTION AND AUTOMATION WITH PROTECTION OF SOFTWARE FROM UNAUTHORIZED ACCESS - Google Patents

Abstract

A microprocessor-based relay protection and automation system containing blocks for galvanic isolation and pre-scaling of input signals in the form of current and voltage, a microprocessor-based system for controlling output relays and alarms in accordance with protection algorithms, and a microprocessor-based system for controlling output relays and alarms in accordance with protection algorithms contains an operational memory device, read-only memory, clock, register, analog input-output device, discrete input-output device and serial channel driver, and the second group of inputs-outputs of the microprocessor control system for output relays and alarms in accordance with the protection algorithms is a group of inputs-outputs for communication with external devices, the third group of inputs-outputs of a microprocessor-based control system for output relays and alarms in accordance with protection algorithms, is a group of inputs-outputs for communication with a PC, which differs in that it contains an analog signal generator, and the microprocessor system for controlling the output relays and alarms in accordance with the protection algorithms contains a microcontroller, a control panel with a keyboard and indication, an identification unit, a second register and a second driver of a serial channel, the input-output group of which is the first group inputs-outputs of a microprocessor control system for output relays and alarms in accordance with protection algorithms, a group of inputs for a microprocessor control system for output relays and alarms in accordance with control algorithms

Description

The utility model relates to electrical engineering, namely to the relay protection technique.

Known microprocessor-based protection system [NN Chernobrovov, V. A. Semenov "Relay protection of energy systems", 1998, p. 776, Fig. 22.1], containing blocks of intermediate transformers, a block of frequency filters, an analog-to-digital converter and a microprocessor system It performs the functions of relay protection, but has large dimensions, limited functionality and is not protected from unauthorized access to software.

The known system is "Microprocessor-based protection system" [Patent RU No. 2173924 Н02Н 7/26 B.I. No. 26 dated 09/20/2001], which contains blocks of galvanic isolation and preliminary scaling of input signals in the form of current and voltage, a block of frequency filters, an analog-to-digital converter, and a microprocessor control system for output relays and signaling in accordance with protection algorithms, perform the functions of relay protection, but it has limited functionality, large dimensions and is not protected from unauthorized access to software.

The closest technical solution is a microprocessor-based protection system - "Microprocessor-based relay protection and automation device with remote control" [RU Patent No. 2222083 7 Н02Н 7/26, G01R 23/165, 31/08 B.I. No. 2 dated January 20, 2004], which contains blocks of galvanic isolation and preliminary scaling of input signals in the form of current and voltage, a block of frequency filters, an analog-to-digital converter, a microprocessor control system for output relays and signaling in accordance with protection algorithms and a transceiver.

The prototype also has large dimensions, limited functionality and is not protected from unauthorized access to software.

The technical result is the expansion of the functionality of the microprocessor relay protection and automation system, reducing the dimensions of the device and the introduction of protection against unauthorized access to software is achieved by introducing:

to the device - shaper of analog signals;

to the microprocessor control system of the output relays and the alarm in accordance with the protection algorithms - the microcontroller, the second driver of the serial channel, the identification node and the control panel, containing a keyboard and indication.

This goal is achieved by the fact that in the well-known microprocessor-based protection system containing galvanic isolation blocks and preliminary scaling of the input signals in the form of current and voltage, a microprocessor-based control system for output relays and signaling in accordance with protection algorithms, and the microprocessor-based control system for output relays and signaling in accordance with protection algorithms, contains random access memory, read-only memory, clock, register, analog device The main input-output device, a discrete input-output device and a serial channel driver, the second group of inputs and outputs of a microprocessor control system for output relays and signaling in accordance with protection algorithms is a group of inputs and outputs for communication with external devices, the third group of inputs and outputs is microprocessor control systems of output relays and alarm in accordance with protection algorithms, is a group of inputs and outputs for communication with a PC, an analog signal former is introduced, and in m a microprocessor control system for output relays and signaling in accordance with protection algorithms, introduced a microcontroller, a remote control containing a keyboard and indication, an identification node, a second register and a second serial channel driver, the input-output group of which is the first group of inputs and outputs of the microprocessor-based output relay control system and an alarm in accordance with protection algorithms, a group of inputs of a microprocessor control system for output relays and an alarm in accordance with algorithms The protection is connected to the group of outputs of the analog signal former, the first and second group of inputs of which are connected to the groups of outputs of the galvanic isolation units and preliminary scaling of the input signals in the form of current and voltage, respectively.

Figure 1 shows the structural diagram of a microprocessor relay protection system and automation;

figure 2 - structural diagrams of the blocks galvanic isolation and preliminary scaling of the input signals in the form of current and voltage. The diagram shows examples of the implementation of one of the galvanic isolation and preliminary scaling of the input signals in the form of current and voltage from the total number of galvanic isolation and preliminary scaling of the input signals, determined by the number of input analog current and voltage signals;

figure 3 is an example implementation of a shaper of analog signals;

figure 4 is an example implementation of a display circuit of the control panel;

figure 5 is an example implementation of a microprocessor control system for output relays and alarm in accordance with protection algorithms;

figure 6 - appearance of the prototype and the claimed device.

Figure 1 marked:

1 - block galvanic isolation and preliminary scaling of the input signals in the form of current;

2 - block galvanic isolation and preliminary scaling of the input signals in the form of voltage;

3 - shaper of analog signals;

4 - microprocessor control system for output relays and alarm in accordance with protection algorithms;

5 - control panel;

5 ₁ - indication;

5 ₂ - keyboard TU 4236-001-74790443-2005 or similar;

6 - identification node DS2401P company "Dallas Semiconductor" or similar;

7 - a group of current signals of the protected object;

8 - group of voltage signals of the protected object;

9, 10 - groups of output signals from the blocks of galvanic isolation and preliminary scaling of the input signals in the form of current and voltage;

11 - group of outputs of the shaper of analog signals;

12 - a group of inputs and outputs for communication with a personal electronic computer (PC) - USB channel;

13 - a group of inputs and outputs for communication with the automated control system channel RS-485;

14 - group of inputs and outputs for communication with external devices i.e. inputs / outputs of an analog input-output device (UABB) and inputs / outputs of a discrete input-output device (UDVV).

Figure 2 marked:

15 - current or voltage transformers of the type TT, VT or similar;

16 - diode assembly type BAV99 firm "PHI" or similar;

17 is an operational amplifier for converting and scaling input signals. As an operational amplifier, you can use a chip type MAX4126ESA firm "Maxim" or similar;

R - resistors type RT0805BRD07 company "Yageo" or similar;

C - capacitors type CC0805KRX9BN104 of the company "Yageo" or similar;

C ₁ - capacitor type T491B685M010AS company "Kemet" or similar;

V ₁ - voltage of 1.65 V;

V ₂ - voltage 3.3 V.

Figure 3 marked:

3 _1.1 ... 3 _1.X - nodes of the formation of analog current signals;

3 _2.1 ... 3 _2.Y - nodes of the formation of analog signals by voltage;

R ₁ - resistors type RC0805FR07 company "Yageo" or similar;

R ₂ - resistors type RC1206JR07 company "Yageo" or similar.

In figure 4 are indicated:

18 - power source type TLV1117-33IDCYR company "Texas Ibstruments" or similar;

19 - register serial communication type 74LVC595APW company "NXP" or similar;

L ₁ - light-emitting diode type L-7104LID of the company "Kingbright" or similar;

V ₃ - voltage 5 V.

Figure 5 marked:

20 - microcontroller type AT91SAM7X512-AU company "Atmel" or similar;

21, 22 - analog-to-digital Converter, the Central processor as part of the microcontroller;

23 - driver for communication with a personal computer type AD376BRM manufactured by "Analog Devices" or similar (USB channel);

24 - driver for communication with ACS type ADM2587EBRWZ company "Analog Devices" or similar (channel RS-485);

25 - device discrete input-output (UDVV);

26 - device analog input-output (UABB);

27 - RAM type FM25CL64-G company "Ramtron" or similar;

28 - ROM type AT45DB642D-TU company "Atmel" or similar;

29 - real-time clock type DS3231SN of the company "Dallas;

30, 31 - button registers of the type 74HC7540DB of the company "NXP" or similar;

32 - serial channel SPI;

33 - serial channel I2C.

Figure 6 marked:

34 is a prototype;

35 - the claimed device.

To simplify the circuit of a microprocessor-based control system for output relays and signaling in accordance with protection algorithms, Figure 5 does not show: a resonator and control circuits, digital isolators, multiplexers, etc. (i.e. elements that do not affect the description of the operation of the device.

The microprocessor-based relay protection and automation system contains galvanic isolation blocks and preliminary scaling of the input signals in the form of current 1 and voltage 2, an analog signal shaper 3 and a microprocessor-based output relay and alarm control system in accordance with protection algorithms 4. A microprocessor-based output relay and alarm control system according to the protection algorithms 4 contains a microcontroller 20, consisting of an analog-to-digital Converter 21 and a processor 22, drivers for communication with PC 23 and ACS 24, analog input-output device 25, discrete input-output device 26, random access memory 27, read-only memory 28, clock 29, registers 30 and 31, control panel 5 with indication 5 ₁ and keyboard 5 ₂ , identification node 6.

The groups of outputs 9 and 10 of the galvanic isolation and preliminary scaling blocks of the input signals in the form of current 1 and voltage 2 are connected, respectively, to the first and second group of inputs of the analog signal conditioner 3, the group of outputs 11 of which is connected to the group of inputs of the microprocessor control system for output relays and signaling in accordance with protection algorithms 4, the second group of inputs and outputs 14 of which is a group of inputs and outputs for communication with external devices, the third group of inputs and outputs 12 is a microprocessor in accordance with protection algorithms 4 of the output relay and alarm control system 4 is a group of inputs and outputs for communication with a personal computer, the first group of inputs and outputs 13 of a microprocessor-based output relay and alarm control system in accordance with protection algorithms 4 is a group of inputs and outputs for communication with ACS.

The microprocessor relay protection system operates as follows: the signals from the primary current transformers 7 and voltage 8 of the protected object are fed to the intermediate transformers 15 of the galvanic isolation and preliminary scaling of the input signals in the form of current and voltage 1 and 2. Intermediate transformers 15 provide galvanic isolation and preliminary scaling input signals. The primary windings of transformers provide the specified thermal stability during overloads. Amplifiers implemented on the chip 17, diode assemblies 16, resistors R are used for preliminary scaling of the signals of intermediate transformers. From the outputs of the amplifiers 17, the signals are fed to the inputs of the analog signal _conditioner 3, _{signal conditioners} 3 _1.1 ... 3 _1.X and 3 _2.1 ... 3 _2.Y , which are used to precisely scale the signals and match the impedances of the intermediate transformers and the analog-to-digital converter 21 of the microcontroller 20 Capacitors C, in the feedback circuit of amplifiers 17, are low-pass filters - they pass current and voltage components of a certain frequency and do not pass high-frequency harmonics, which are noise distorting the sinusoid current and voltage. Next, the analog signals on channel 11 are fed to the analog-to-digital converter 21 of the microcontroller 20 to change the waveform to discrete (digital), because subsequent processing of the signals is performed by the processor 22. The operation of the analog-to-digital converter 21 is controlled by the processor 22 of the microcontroller 20, which provides digital filtering of the input signals, calculates the secondary electrical parameters of the network, performs self-diagnosis procedures, and also supports communication with the control panel 5 and keyboard 5 ₂ , through registers 30 and 31, input / output devices 25 and 26, on channel 33 (I2C).

Thus, in accordance with protection algorithms 4, the microprocessor control system of the output relays and the alarm system receives the values of the electrical parameters of the protected object from the analog-to-digital converter 21 and the status of the digital inputs from the air-conditioning device 25. Based on this information, as well as the values of program keys and settings stored in the ROM 28, are generated, in accordance with the protection algorithms, control commands for the output relays and alarms, which are received through the WWRF 26 through channel 14 to the objects controlled I signaling. More detailed information on the operation of the microprocessor-based control system for output relays and signaling in accordance with protection algorithms is given in [N.N. Chernobrov, V. A. Semenov "Relay protection of energy systems" 1998, pp. 778-783].

In addition to performing protection and automation functions, the processor 22 of the microcontroller 20 provides an exchange with a personal computer and automatic control system via channels 12 and 13, through drivers 23 and 24, respectively.

The microprocessor relay protection and automation system provides the following operational capabilities:

- performance of protection, automation and control functions;

- local and remote setting of the internal configuration programmatically and its storage. Automatic or remote switching of settings and configuration programs;

- alarm operation of protection and automation, the position of switching devices, device malfunctions;

- registration and storage of oscillograms, a log of emergency and operational events, accumulative information about the number and time of starts and trips of protections and automation;

- the user sets the parameters of the recorded waveforms: start conditions, the amount of recorded information and the duration of the accident recording;

- monitoring and indicating the position of the circuit breaker, as well as the serviceability of its control circuits, local and remote control of the circuit breaker, switching control mode, circuit breaker diagnostics;

- measurement of current electrical parameters of the protected object;

- monitoring the health of measuring voltage transformers;

- technical accounting of electricity;

- determination of the place of damage;

- the function of the calendar and clock of astronomical time with synchronization of the clock on ACS;

- continuous operational performance monitoring (self-diagnosis) throughout the entire operation time;

- blocking of all outputs in the event of a device malfunction to eliminate false alarms;

- galvanic isolation of all inputs and outputs, to ensure high noise immunity;

- high resistance and insulation strength of the inputs and outputs relative to the housing and between each other to increase the resistance of the device to overvoltages arising in the secondary circuits of switchgear;

- protection against false positives of discrete input circuits of the device in case of interference and insulation violations in the circuits of the operational current of the switchgear;

- User reprogramming of basic functional software.

Basic protection functions performed by a microprocessor-based relay protection and automation system:

- three-stage maximum current protection against interphase faults with current control in two or three phases;

- directional or non-directional protection against single-phase earth faults with zero-sequence current control, its high-frequency components and zero-sequence voltage;

- protection against phase failure and load asymmetry in reverse sequence current;

- protection against unbalanced mode by voltage of the negative sequence;

- undervoltage protection with line voltage and reverse sequence voltage control;

- overvoltage protection with line voltage and reverse sequence voltage control;

- differential current cutoff.

Basic automation functions performed by a microprocessor relay protection and automation system:

- automatic inclusion of a reserve with automatic restoration of the normal mode circuit;

- double automatic repeated inclusion;

- redundancy for failures of circuit breakers with current control;

- logical tire protection;

- execution of commands of an external device of frequency automation.

Alarm functions performed by microprocessor relay protection and automation:

- triggering of protection and automation;

- alarm;

- ringing alarm;

- generalized alarm.

Functions for measuring network parameters performed by a microprocessor-based relay protection and automation system:

- measurement of current values of currents and voltages;

- measurement of current values 3I ₀ ;

- calculation of phase shifts between the main harmonics of the current 3I ₀ and voltage 3U ₀ , phase currents I _A , I _C and line voltages U _BC , U _AB, respectively;

- calculation of currents and voltages of the forward and reverse sequence;

- calculation of current 3I ₀ and voltage 3U ₀ for phase currents and voltages;

- frequency measurement;

- calculation of the power factor cos φ;

- calculation of active, reactive and apparent power;

- the maximeter of the measured values.

The control panel 5, built into the microprocessor control system for output relays and alarms in accordance with protection algorithms, contains 24 LEDs (each of them can be programmed by the user using the appropriate software), as well as ten buttons for navigating the menu, viewing, entering or dumping information.

Identification node 6 containing a unique identification number (code). The identification node protects the device software from unauthorized access and changes by the consumer.

Thus, the introduction of analog signal shaper into the microprocessor relay protection and automation system, and the output relay and alarm control system in the microprocessor control system in accordance with the microcontroller protection algorithms, the second register and the second driver, the remote control and the identification node - expands the device’s functionality and makes it absolutely a universal device that removes almost all problems when ordering, designing, upgrading switchgear at the facility and when determining the composition of spare parts, as well as bespechivaet software protection device against unauthorized access by the consumer.

The exclusion from the microprocessor system of relay protection and automation, in comparison with the prototype, an analog-to-digital converter, a block of frequency filters and a transceiver led to a decrease in the dimensions of the device by 2 times (see Figure 6).

Claims (1)

A microprocessor-based relay protection and automation system containing galvanic isolation and preliminary scaling of input signals in the form of current and voltage, a microprocessor-based output relay and alarm control system in accordance with protection algorithms, and the microprocessor-based output relay and alarm control system in accordance with protection algorithms contains an operational storage device, read-only memory device, clock, register, analog input-output device, device in a discrete input-output and a serial channel driver, the second group of inputs and outputs of a microprocessor control system for output relays and alarm in accordance with protection algorithms is a group of inputs and outputs for communication with external devices, the third group of inputs and outputs of a microprocessor control system for output relays and signaling in accordance with protection algorithms, is a group of inputs and outputs for communication with a PC, characterized in that it contains an analog signal former, and micropro the processor control system for the output relays and the alarm system in accordance with protection algorithms comprises a microcontroller, a control panel with a keyboard and an indication, an identification node, a second register and a second serial channel driver, the group of inputs and outputs of which is the first group of inputs and outputs of the microprocessor control system of the output relays and alarm in accordance with protection algorithms, group of inputs of a microprocessor control system for output relays and alarm in accordance with protection algorithms It is connected to the group of outputs of the shaper of analog signals, the first and second groups of inputs of which are connected to the groups of outputs of the galvanic isolation units and preliminary scaling of the input signals in the form of current and voltage, respectively.