CN102255278B - Comprehensive leakage protector - Google Patents

Abstract

The invention is an intelligent leakage comprehensive protector with communication function. The protector includes zero-sequence current transformer, A-phase load current transformer, B-phase load current transformer, C-phase load current transformer, voltage divider, signal conditioning circuit, single-chip microcomputer, switchgear, communication module and power supply; , the output of the zero-sequence current transformer, A-phase load current transformer, B-phase load current transformer, C-phase load current transformer and voltage divider is connected to the signal conditioning circuit, and the output of the signal conditioning circuit is connected to the single-chip microcomputer; the switch device It is connected with the single-chip computer; the communication module is connected with the single-chip computer. The integrated leakage protector of the present invention can realize overcurrent, short circuit, leakage, and abnormal voltage (overvoltage or undervoltage) protection, and has the function of delay action and automatic reclosing. Multiple intelligent integrated leakage protectors can pass through their respective communication modules. A leakage protection monitoring network is formed in a flexible manner to realize remote monitoring of low-voltage power grid leakage protection.

Description

A leakage comprehensive protector

technical field

The technical solution of the present invention relates to an automatic disconnection emergency protection circuit device with a communication function that directly responds to unexpected changes from normal electrical working conditions, specifically an intelligent leakage integrated circuit with a communication function Protector and method of operation.

technical background

Residual current protection device <residual current protector> is an important equipment in low-voltage power grid, which plays an important role in preventing electric leakage fire and protecting people from electric shock. At present, residual current protection devices are generally installed in low-voltage power grids, but the existing residual current protection devices have the following problems: (1) they can only provide basic protection (such as leakage circuit breaker patent CN101562328A), in order to prevent distribution transformers from In case of overcurrent, short circuit or overvoltage damage, other protective devices such as fuses must be installed at the same time as the residual current protection device, which will increase the size of the distribution box and increase the cost. (2) Existing residual current protection devices generally do not have communication functions, and are basically stand-alone operation, unable to provide the power sector with data on the operation status of the power grid, especially the residual current situation; at the same time, the management of it by the power sector is also relatively cumbersome. Regular inspections are required. Therefore, the current residual current protection device of the power grid cannot meet the needs of the power sector for monitoring the low-voltage power grid, nor can it meet the requirements of the future smart grid development.

In order to overcome the above problems, many people have proposed a solution: CN1373490A proposes a multifunctional integrated intelligent comprehensive leakage protector with a novel structure, which uses electromagnets to pull in and release to control the tripping and closing of the main switch. The structure of the electric switch is simple, and the action is not corroded by air pollution, salty sea breeze, acid mist, etc. Under load conditions, the electrical and mechanical life can reach more than 100,000 times, and it is assembled together with a current transformer and a signal processing circuit. In the box body, the protector can easily realize the functions of overcurrent, short circuit and leakage protection, but the leakage protector does not have the function of voltage protection, nor does it have the function of communication, so it cannot solve the problems existing in existing residual current protection devices. The problem. CN101969288A proposes a communication adapter for a dedicated multifunctional leakage circuit breaker that adopts GSM wireless communication technology and power line carrier communication technology, which can be used for both wired and wireless transmission and reception, and is used to transmit relevant information and control instructions for setting parameters of the leakage circuit breaker , Automatically complete the action of opening, re-buckle and reclosing after tripping, so that the power grid can be put into operation in time. Although the communication adapter has a communication function, it must be used in conjunction with the leakage protector to realize the protection function. In addition, the communication adapter can only realize the two-way communication between the leakage protector and the control equipment, and does not have the function of building a leakage protection monitoring network. , so its application has certain limitations.

In a word, none of the existing technologies can well solve the problems existing in the residual current protection device.

Contents of the invention

The purpose of the present invention is to provide an intelligent integrated leakage protector with communication function: the integrated leakage protector has a compact structure and a high degree of functional integration, and can protect against overcurrent, short circuit, leakage, abnormal voltage (overvoltage or ) fault protection, and has a variety of communication methods based on wired communication, wireless communication and national public mobile network, and can flexibly build a leakage protection monitoring network, which overcomes the shortcomings of current leakage protectors that have single functions and cannot realize networked monitoring. It well solves the problems existing in the current residual current protection device, and has the function of delay action and automatic reclosing.

The technical scheme that solves the above-mentioned technical problem is:

A leakage comprehensive protector, including zero-sequence current transformer, A-phase load current transformer, B-phase load current transformer, C-phase load current transformer, voltage divider, signal conditioning circuit, single-chip microcomputer, switch device, communication module and power supply; among them, the output of the zero-sequence current transformer, A-phase load current transformer, B-phase load current transformer, C-phase load current transformer and voltage divider is connected with the signal conditioning circuit, and the output of the signal conditioning circuit is connected with the single-chip microcomputer connected; the switching device is connected with the single-chip computer; the communication module is connected with the single-chip computer; the input of the power supply is connected with the grid, and the output of the power supply is connected with the signal conditioning circuit, the single-chip computer and the communication module.

The switch device is an air circuit breaker or a relay.

The signal conditioning circuit is composed of three functional circuits, a leakage current signal conditioning circuit, a voltage signal conditioning circuit and a load current signal conditioning circuit, wherein the leakage current signal conditioning circuit is composed of an operational amplifier, a resistor, a capacitor, and a diode, and is used for Process the leakage current signal input by the zero-sequence current transformer, the input of the leakage current signal conditioning circuit is connected to the output of the zero-sequence current transformer, the output of the leakage current signal conditioning circuit is connected to the single-chip microcomputer; the voltage signal conditioning circuit consists of three identical structures They are composed of operational amplifiers, resistors, capacitors and diodes to process the three-phase voltage signal input by the voltage divider. The input of the voltage signal conditioning circuit is connected to the output of the voltage divider. The voltage signal conditioning circuit The output of the load current signal is connected to the microcontroller; the load current signal conditioning circuit is composed of three parts with the same structure, which are composed of operational amplifiers, resistors, capacitors and diodes, and are used to process the three-phase load current signals input by the load current transformer , the input of the load current signal conditioning circuit is respectively connected to the output of the A-phase load current transformer, the B-phase load current transformer, and the C-phase load current transformer, and the output of the load current signal conditioning circuit is connected to the single-chip microcomputer;

The communication module is composed of a wireless communication circuit, a wired communication circuit and a communication circuit based on the national public mobile communication network. Among them, the wireless communication circuit is a module circuit based on a wireless communication integrated circuit; the wired communication circuit is based on a field The module circuit of bus technology; the communication circuit based on the national public mobile communication network is a data transmission module using the national public mobile communication network;

The national public mobile communication network mentioned is GSM national public mobile communication network, CDMA/CDMA2000 national public mobile communication network, WCDMA national public mobile communication network or TDSCDMA national public mobile communication network;

The leakage comprehensive protector may also include the following auxiliary components: leakage simulation generator, keyboard/display circuit, real-time clock circuit, external memory and frequency detection circuit; these auxiliary components are all connected with power supply and single-chip microcomputer.

The operation method for realizing the protection function of the intelligent leakage comprehensive protector with communication function includes the following steps:

1) The zero-sequence current transformer senses the leakage current in the power grid, the A-phase load current transformer, B-phase load current transformer and C-phase load current transformer sense the load current in the line, and the voltage divider senses the line voltage , their output is connected with the signal conditioning circuit, after being transformed and amplified by the signal conditioning circuit, it is input to the single chip microcomputer for analog-to-digital conversion; the single chip microcomputer analyzes and judges the sampled value:

(a) When the leakage current reaches or exceeds the leakage action current threshold, the single-chip microcomputer sends a trip command after delaying the set time to make the switch device act, and the switch device cuts off the fault circuit, so that the fault leakage is protected;

(b) When the load current in the line reaches or exceeds the overcurrent protection action threshold, the single-chip microcomputer sends a trip command after delaying the set time to make the switching device act, and the switching device cuts off the faulty circuit, so that the overload current is protected;

(c) When the line voltage is higher than the overvoltage protection action threshold or lower than the undervoltage protection action threshold, the single-chip microcomputer sends a tripping command after delaying the set time to make the switch device act, and the switch device cuts off the faulty circuit, so that the abnormal voltage is eliminated Protect;

When the intelligent leakage integrated protector trips, go to step 2), otherwise go to step 3);

2) If the automatic reclosing function is turned on, the intelligent leakage comprehensive protector will automatically reclose once within 40s~60s, and go to step 1); if the line fault still exists after 1 reclosing, it will trip again The rear switching device will be blocked;

3) If the power failure protection function is turned on, when the line is powered off, the single-chip microcomputer issues a trip command to make the switch device act to cut off the circuit, and automatically reclose the switch to restore the power supply after the voltage returns to normal; otherwise, go to step 1).

The operation method for realizing the communication function of the intelligent leakage comprehensive protector with communication function includes the following steps:

1) Under the condition that no fault occurs in the line, the single-chip microcomputer periodically detects the state of the sending flag and the receiving flag: when the sending flag is 1, go to step 2); when the receiving flag is 1, go to step 4 ); otherwise continue to wait;

2) The single-chip microcomputer loads the target address of the communication and the content of the data sent, and selects the communication mode according to the connection status, and turns to step 3) after success, otherwise reports that there is a fault in the user's communication line;

3) Send the communication data to the target address, and go to step 1 after sending;

4) The single-chip microcomputer determines the communication mode for data reception, and turns to step 5) after success, otherwise turns to step 1);

5) receive the communication data packet, and judge whether its communication address is the local address: if yes, then accept the communication data packet and go to step 6); otherwise, discard the received communication data packet and go to step 1);

6) Process the received data packet, and turn to step 1 after processing;

The operation method of the intelligent leakage comprehensive protector with communication function to realize the auxiliary function is:

1) Under the condition that the single-chip microcomputer is not running protection and communication functions, the single-chip microcomputer operation display update and keyboard scanning program: the single-chip microcomputer regularly calculates the leakage current, load current, line voltage and rated action value of leakage protection, over-current protection and abnormal voltage protection, The action time, the cause of the action and the fault value are sent to the display circuit to update the display content; when the data is updated, the single-chip microcomputer runs the keyboard scanning program to detect whether a key is pressed, and when a key is pressed, the single-chip microcomputer executes the key processing program to complete the setting and query functions; after the display update and keyboard scanning programs are executed, the microcontroller returns to the protection program;

2) Under the condition that the single-chip microcomputer does not run the protection and communication functions, the single-chip microcomputer runs the real-time time update program, regularly reads the real-time time provided by the real-time clock circuit, and uses it for fault records and operation history records; after the real-time time is updated, the single-chip microcomputer returns into the saver;

3) Under the condition that the single-chip microcomputer is not running protection and communication functions, the single-chip microcomputer runs the stored program, and stores the leakage current, load current, and line voltage during line operation in the external memory at regular intervals. After the storage is completed, the single-chip microcomputer returns into the saver;

When a line fault occurs, the single-chip microcomputer also runs the storage program to store the fault information in the external memory, and after the storage is completed, the single-chip microcomputer returns to the protection program;

4) The frequency detection circuit directly obtains the AC signal from the power grid and is shaped into a square wave signal by the zero comparison circuit to be input to the single-chip microcomputer. Timing of a cycle signal to detect the time of a cycle to realize automatic tracking of the grid frequency;

5) Leakage simulation generation circuit simulation produces fault leakage, when the leakage test button is pressed, leakage simulation generation circuit produces a simulated fault leakage current, when single-chip microcomputer detects this, sends leakage trip command, for checking protector of the present invention Is it working properly.

Beneficial effect of the present invention, compared with prior art, has the following advantages:

The intelligent leakage comprehensive protector with communication function of the present invention can realize overcurrent, short circuit, leakage, abnormal voltage (overvoltage or undervoltage) protection, has delay action and automatic reclosing function, and has communication function, multiple intelligent The integrated leakage protector can form a leakage protection monitoring network in a flexible way through its respective communication modules, realizing remote monitoring of low-voltage power grid leakage protection. At the same time, the intelligent integrated leakage protector as the control center can also use the national public mobile communication network (GSM, CDMA/CDMA2000, WCDMA, TDSCDMA) communicate with the user's mobile phone or host computer, and the user can also view or modify the parameter settings of the intelligent leakage comprehensive protector node in the network through the mobile phone or the host computer, and can realize remote switching and closing through the mobile phone or the host computer gate operation. Therefore, the intelligent integrated leakage protector with communication function of the present invention has a complete protection function and can carry out network communication, so that the staff can monitor the operation of the power grid anytime and anywhere. However, the existing leakage protectors have single functions and generally do not have communication functions, so that the use of users is limited, and they cannot meet the needs of the power sector for monitoring low-voltage power grids, nor can they meet the requirements of power grid development.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is a connection block diagram of various components of the comprehensive leakage protector in embodiment 1.

Fig. 2 is a connection block diagram of various components of the comprehensive leakage protector in embodiment 2.

Fig. 3 is a schematic diagram of the connection of the monitoring network in the present invention.

Fig. 4 is a circuit connection diagram of Embodiment 2 of the present invention, wherein 4a is the circuit components except the communication module, and 4b is the circuit of the communication module.

Fig. 5 is the program block diagram that the present invention realizes protection and communication function, and wherein 5a is - the program block diagram of - leakage integrated protector realizes protection function, Fig. 5b is - - the program block diagram of leakage integrated protector realizes communication sending function, Fig. 5c is ——Program block diagram of the leakage integrated protector to realize the communication receiving function.

In the figure, 1——zero-sequence current transformer; 2——phase A load current transformer; 3——phase B load current transformer; 4——phase C load current transformer; 5——voltage divider; 6 ——Signal conditioning circuit; 7—Single chip microcomputer; 8—Switch device; 9—Communication module; 10—Power supply; 11—Leakage simulation generator; 12—Keyboard/display circuit; 13—Real-time clock circuit ; 14——external memory; 15——frequency detection circuit; 16——leakage comprehensive protector.

Detailed ways

Example 1

Fig. 1 shows that the intelligent leakage comprehensive protector with communication function of the present invention comprises zero-sequence current transformer (1), A-phase load current transformer (2), B-phase load current transformer (3), C-phase load current transformer A transformer (4), a voltage divider (5), a signal conditioning circuit (6), a single-chip microcomputer (7), a switch device (8), a communication module (9) and a power supply (10).

The connection relationship is: the zero-sequence current transformer (1) senses the leakage current in the grid, the A-phase load current transformer (2), the B-phase load current transformer (3) and the C-phase load current transformer (4) Sensing the load current in the line, the voltage divider (5) senses the line voltage; zero-sequence current transformer (1), A-phase load current transformer (2), B-phase load current transformer (3), C-phase The output of the load current transformer (4) and the voltage divider (5) is connected to the signal conditioning circuit (6), and the output of the signal conditioning circuit (6) is connected to the single-chip microcomputer (7), and the single-chip microcomputer (7) is responsible for signal analysis and processing The switchgear (8) is connected with the single-chip microcomputer (7), and the tripping action is completed under the control of the single-chip microcomputer (7) to cut off the fault circuit; the communication module (9) is connected with the single-chip microcomputer (7), and under the control of the single-chip microcomputer (7) The communication function is completed; the power supply (10) supplies power for the signal conditioning circuit (6), the single-chip microcomputer (7) and the communication module (9).

As shown in Figure 4a and Figure 4b, in the embodiment: zero-sequence current transformer RCT (1), A-phase load current transformer (2), B-phase load current transformer (3), C-phase load current transformer ( 4), the voltage divider (5) is respectively connected with the signal conditioning circuit (6), and the output of the signal conditioning circuit (6) is connected to the single-chip microcomputer (7), provides leakage current, load current and line voltage signal for the single-chip microcomputer (7); The communication module (9) is connected with the single-chip microcomputer (7), and completes the communication function under the control of the single-chip microcomputer (7); the button/display circuit (12) is connected with the single-chip microcomputer (7) and is controlled by the single-chip microcomputer (7), and the display circuit (12 ) cyclically display the leakage current, load current and line voltage, and display the rated action value, action time, cause of the action and fault value of the leakage protection, over-current protection and abnormal voltage protection. The keyboard (12) is used to select the rated action value , action time and query historical records; the real-time clock circuit (13) is connected with the single-chip microcomputer (7) and is controlled by the single-chip microcomputer (7), and provides real-time time for the intelligent leakage comprehensive protector; the external memory (14) is connected with the single-chip microcomputer (7) And be controlled by single-chip microcomputer (7), be used for storing leakage current, load current, line voltage and fault information when line is running; Frequency detection circuit (15) is connected with single-chip microcomputer (7), and grid frequency signal is input single-chip microcomputer (7) Leakage simulation generating circuit (11) simulates fault leakage; power supply (10) is single-chip microcomputer (7), signal conditioning circuit (6), communication module (9), button/display circuit (12), real-time clock circuit (13) , external memory (14) and frequency detection circuit (15) power supply.

As shown in Figure 4a, in the embodiment: the zero-sequence current transformer (1) is a leakage transformer made of 1J85 Permalloy, and its inner diameter is 40mm; A-phase load current transformer (2), B-phase load current transformer (3) and C-phase load current transformer (4) are the electromagnetic type current transformer that silicon steel plate manufactures, and rated current is 100A; Voltage divider (5) is made up of resistor series connection; Signal conditioning circuit (6) is made up of operational amplifier , resistors, capacitors and diodes, which are divided into three functional circuits: the operational amplifier U6A and its connected resistors, capacitors and diodes form a leakage current signal conditioning circuit; operational amplifiers U3A, U4A, U4B and their connected resistors A voltage signal conditioning circuit is composed of a capacitor, a capacitor and a diode; operational amplifiers U3B, U4C, U4D and resistors, capacitors and diodes connected to them form a load current signal conditioning circuit; the model of the operational amplifier in the signal conditioning circuit (6) is MCP6004; Power supply (10) is made of industrial frequency transformer, diode 1N4007, 220 microfarad electrolytic capacitor and integrated circuit LM7805; Single-chip microcomputer (7) is ATmega32 single-chip microprocessor; Switchgear (8) is the air circuit breaker of rated current 100A, also Can be a relay. The three functional circuits of the leakage current signal conditioning circuit, the voltage signal conditioning circuit and the load current signal conditioning circuit are all well-known circuits in the art, and their composition and connection relationship are known to those of ordinary skill in the art. The leakage signal conditioning circuit is composed of operational amplifiers, resistors, capacitors and diodes, and is used to process the leakage current signal input by the zero-sequence current transformer; the voltage signal conditioning circuit is composed of three parts with identical structures, which are composed of operational amplifiers, Composed of resistors, capacitors and diodes, it is used to process the three-phase voltage signal input by the voltage divider; the load current signal conditioning circuit consists of three parts with the same structure, and they are all composed of operational amplifiers, resistors, capacitors and diodes , used to process the three-phase load current signal input by the load current transformer.

As shown in Figure 4b, in the embodiment: the communication module (9) is made up of integrated circuit, SIM card slot, resistor, capacitor, inductance coil, diode, triode, crystal oscillator and radio frequency antenna, is divided into three functional circuits : integrated circuit U15nRF2401, resistor, capacitor, crystal oscillator, inductance coil and radio frequency antenna RF ANT form the wireless communication circuit of communication module (9); integrated circuit U7MAX485, optocoupler U5, U9, U10 (PS2501), resistor The wired communication circuit that forms communication module (9) with triode; Integrated module U14SIM300C, SIM card slot U16, resistor, capacitor, triode and diode form the communication circuit based on national public mobile communication network of communication module (9), embodiment Among them, the GSM national public mobile communication network is adopted.

Figure 1 shows that the zero-sequence current transformer (1), A-phase load current transformer (2), B-phase load current transformer (3), C-phase load current transformer (4) and voltage divider (5) The output signal is conditioned and amplified by the signal conditioning circuit (6), and then input to the single-chip microcomputer (7) for analog-to-digital conversion. The single-chip microcomputer (7) analyzes and judges the collected electrical parameters, and completes leakage, overload, and abnormal voltage protection. The working process and the run method is:

(a) When the leakage current reaches or exceeds the leakage action current threshold, the single-chip microcomputer (7) sends a trip command after delaying the set time to make the switch device (8) act, and the switch device (8) cuts off the fault circuit to make the fault leakage be protected.

(b) When the load current in the line reaches or exceeds the overcurrent protection action threshold, the single-chip microcomputer (7) sends a tripping command after delaying the set time to make the switch device (8) act, and the switch device (8) cuts off the fault circuit , so that the overload current is protected.

(c) When the line voltage is higher than the overvoltage protection action threshold or lower than the undervoltage protection action threshold, the single-chip microcomputer (7) sends a tripping command after delaying the set time to make the switch device (8) act, and the switch device (8) ) to cut off the fault circuit, so that the abnormal voltage is protected.

Fig. 1 shows that each intelligent leakage comprehensive protector has a communication module (9), and the communication module (9) realizes the communication function under the control of the single-chip microcomputer (7), and its working process and operation method are: multiple intelligent leakage comprehensive protection The devices are connected to each other through their respective communication modules (9) to form a leakage protection monitoring network. This connection method can be wired, wireless, or a combination of wired and wireless; each integrated leakage protector has It is a network node, and any network node can be used as the control center of the network, but the control center is unique at the same time; the control center controls the operation of the entire network and is responsible for collecting real-time operating data and fault information of the lines protected by each network node At the same time, it also controls the working status of the network nodes. The control center can also use the national public mobile communication network to communicate with the user's mobile phone or host computer to inform the user of the operating status of the network node. The user can also view or modify any network node through the mobile phone or host computer. The parameters of the node can be set, and the remote opening and closing operation can be performed through the mobile phone or the host computer.

Example 2

Fig. 2 shows that the intelligent leakage comprehensive protector with communication function of the present invention added with auxiliary circuit comprises zero-sequence current transformer (1), A-phase load current transformer (2), B-phase load current transformer (3) ), C-phase load current transformer (4), voltage divider (5), signal conditioning circuit (6), single chip microcomputer (7), switchgear (8), communication module (9) and power supply (10), leakage simulation Generator (11), keyboard/display circuit (12), real-time clock circuit (13), external memory (14) and frequency detection circuit (15).

The connection relationship is: the zero-sequence current transformer (1) senses the leakage current in the grid, the A-phase load current transformer (2), the B-phase load current transformer (3) and the C-phase load current transformer (4) Sensing the load current in the line, the voltage divider (5) senses the line voltage; zero-sequence current transformer (1), A-phase load current transformer (2), B-phase load current transformer (3), C-phase The output of the load current transformer (4) and the voltage divider (5) is connected to the signal conditioning circuit (6), and the output of the signal conditioning circuit (6) is connected to the single-chip microcomputer (7), and the single-chip microcomputer (7) is responsible for signal analysis and processing The switchgear (8) is connected with the single-chip microcomputer (7), and the tripping action is completed under the control of the single-chip microcomputer (7) to cut off the fault circuit; the communication module (9) is connected with the single-chip microcomputer (7), and under the control of the single-chip microcomputer (7) Finish the communication function; Leakage simulation circuit is connected with single-chip microcomputer, is used to check whether protector of the present invention works normally; Circular display of parameters and protector setting parameters, and the user's personalized settings are passed to the single-chip microcomputer (7) through the keyboard (12); the real-time clock (13) is connected with the single-chip microcomputer to provide a real-time clock signal for the single-chip microcomputer (7); the external memory (14) is connected with single-chip microcomputer (7), is used for regularly storing the leakage current, load current, line voltage and fault information when the line is running; the frequency detection circuit (15) directly obtains the AC signal from the power grid and is formed by zero comparison circuit The square wave signal is input into the single-chip microcomputer (7); the power supply (10) is a signal conditioning circuit (6), a single-chip microcomputer (7), a communication module (9), a leakage simulation generator (11), a keyboard/display circuit (12), and a real-time clock Circuit (13), external memory (14) and frequency detection circuit (15) are powered.

Adding auxiliary functions to expand the basic functions of the comprehensive leakage protector in the embodiment helps users to use the device more conveniently.

The output signals of the zero-sequence current transformer (1), A-phase load current transformer (2), B-phase load current transformer (3), C-phase load current transformer (4) and voltage divider (5) are conditioned After the circuit (6) is conditioned and amplified, it is input to the single-chip microcomputer (7) for analog-to-digital conversion. The single-chip microcomputer (7) analyzes and judges these electrical parameters, and completes leakage, overload, and abnormal voltage protection. Its working process and operation method are:

(a) When the leakage current reaches or exceeds the leakage action current threshold, the single-chip microcomputer (7) sends a trip command after delaying the set time to make the switch device (8) act, and the switch device (8) cuts off the fault circuit to make the fault leakage be protected.

(b) When the load current in the line reaches or exceeds the overcurrent protection action threshold, the single-chip microcomputer (7) sends a tripping command after delaying the set time to make the switch device (8) act, and the switch device (8) cuts off the fault circuit , so that the overload current is protected.

(c) When the line voltage is higher than the overvoltage protection action threshold or lower than the undervoltage protection action threshold, the single-chip microcomputer (7) sends a tripping command after delaying the set time to make the switch device (8) act, and the switch device (8) ) to cut off the fault circuit, so that the abnormal voltage is protected.

After the intelligent leakage comprehensive protector trips due to leakage, overcurrent or abnormal voltage, when the automatic reclosing function is turned on, it will automatically reclose once within 40s~60s. If the fault still exists after reclosing, it will trip again and make the switch The device (8) is locked. In addition, if the power failure protection function is turned on, when the line is powered off, the single chip microcomputer (7) will issue a trip command to make the switch device (8) act to cut off the circuit, and will automatically reclose to restore power supply after the voltage returns to normal.

Each intelligent integrated leakage protector has a communication module (9), and the communication module (9) realizes the communication function under the control of the single-chip microcomputer (7). The communication modules (9) are connected to each other to form a leakage protection monitoring network. This connection method can be wired, wireless, or a combination of wired and wireless; each integrated leakage protector is a network node. And any network node can be used as the control center of the network to control the operation of the entire network, but the control center is unique at the same time; the control center is responsible for collecting real-time operation data and fault information of the lines protected by each network node, and also controls The working status of the network nodes, the control center can also use the national public mobile communication network to communicate with the user's mobile phone or host computer, the user can view or modify the parameter settings of any node in the network through short messages or the host computer, and can pass SMS or The upper computer performs remote opening and closing operations on it.

The operation method that the auxiliary components of the intelligent leakage comprehensive protector with communication function of the present invention realize the auxiliary function is: the single-chip microcomputer (7) sends the leakage current, load current and line voltage to the display circuit (12), and the display circuit (12) Cycle display leakage current, load current and line voltage, and display leakage protection, overcurrent protection and abnormal voltage protection rated action value, action time, cause of action and fault value. Keyboard (12) is used for selecting rated action value, action time and query history record. The real-time clock circuit (13) provides real-time time for the intelligent leakage comprehensive protector, which is used for fault records and operation history records, so that users can understand the operation status of the line in more detail. The external memory (14) is used for regularly storing leakage current, load current, line voltage and fault information during line operation, which is convenient for users to inquire. The frequency detection circuit (15) directly obtains the AC signal from the power grid and forms a square wave signal into the single-chip microcomputer (7) through a zero comparison circuit. A period of time, to achieve automatic tracking of grid frequency. Leakage simulation generation circuit (11) simulates and generates fault leakage, and when the single-chip microcomputer (7) detects the simulation fault leakage, it sends a leakage trip command to check whether the protector of the present invention works normally. The power supply (10) supplies power to these circuits simultaneously.

Fig. 3 shows that a plurality of intelligent integrated earth leakage protectors with communication functions of the present invention, user mobile phones and host computers can form an earth leakage protection monitoring network. The schematic diagram shown in Figure 3 is composed of five integrated leakage protectors, a user mobile phone and a host computer. In practical applications, the number of networked devices can be increased as needed. In Figure 3, each integrated leakage protector is a network node, of which node 1 is the control center, and the communication mode between nodes can be wired or wireless, and the single-chip microcomputer will automatically select the appropriate communication mode. The control center controls the operation of the entire network, but the control center is unique at the same time; the control center is responsible for collecting real-time operating data and fault information of the lines protected by each network node, and also controls the working status of the network nodes. The control center can also use The national public mobile communication network communicates with the user's mobile phone or host computer. The user can view or modify the parameter settings of any node in the network through the mobile phone or the host computer, and can perform remote opening and closing operations through the mobile phone or the host computer.

As shown in Figure 4a, the zero-sequence current transformer RCT (1) passes through the A, B, C phase lines and the neutral line N of the power line, including two secondary sides composed of two coils, one of which is It is connected to the signal conditioning circuit (6), and the other secondary side, the button S1 and the resistor R1 form a leakage analog generating circuit (11).

As shown in Figure 4a, the A-phase load current transformer (2) CT1, the B-phase load current transformer (3) CT2 and the C-phase load current transformer (4) CT3 pass through the A, B, and C phases of the power line respectively. lines, their outputs are connected to the signal conditioning circuit (6).

As shown in Figure 4a, the voltage divider (5) is composed of R2, R4, R5, R7, R8, and R9. The input end of the voltage divider (5) is connected to the three-phase voltage of A, B, and C, and the output end of the voltage divider (5) is connected to the signal The conditioning circuit (6) is connected.

As shown in Fig. 4a, in the signal conditioning circuit (6): (a) leakage current signal conditioning. R26, C15 are connected with the output of the zero-sequence current transformer RCT (1), and the leakage current signal is converted into a voltage signal; the operational amplifier U6A, C14, R23, R24, R30 and R32 form a leakage signal amplification circuit, and the amplified signal is passed through R35 inputs single-chip microcomputer (7). (b) Load current signal conditioning. The load current signal conditioning circuit is composed of three circuits with the same structure: the output signal of the A-phase load current transformer (2) CT1 is connected to the R40 of the signal conditioning circuit (6), and the A-phase load current signal is converted into a voltage signal. The amplifying circuit formed by the amplifier U3B, R34, R37, D12 and D13 is amplified and input to the rectifying circuit formed by D14, R39, R41 and C16, and the signal is rectified into direct current and then input to the single chip microcomputer (7) through R38. The output signal of the B-phase load current transformer (3) CT2 is connected to the R46 of the signal conditioning circuit (6), and the B-phase load current signal is converted into a voltage signal, and the amplifier circuit composed of operational amplifiers U4C, R42, R43, D15 and D16 is used. After being amplified, it is input to the rectification circuit formed by D17, R45, R48 and C20, and the signal is rectified into direct current and then input to the single-chip microcomputer (7) through R44. The output signal of the C-phase load current transformer (3) CT3 is connected to the R52 of the signal conditioning circuit (6), and the C-phase load current signal is converted into a voltage signal, and the amplifier circuit composed of operational amplifiers U4D, R49, R50, D18 and D19 is used. After being amplified, it is input to the rectification circuit formed by D20, R51, R53 and C26, and the signal is rectified into direct current and then input to the single-chip microcomputer (7) through R47. (c) Line voltage signal conditioning. The line voltage signal conditioning circuit is composed of three circuits with the same structure: R2 and R4 of the voltage divider (5) sense the A-phase voltage, and its output signal is connected to the rectification circuit composed of D5, C10 and R6, and the rectified DC After the signal passes through the voltage follower formed by the operational amplifier U3A, it is input into the single-chip microcomputer (7) through R3. R5 and R7 of the voltage divider (5) sense the B-phase voltage, and its output signal is connected to the rectification circuit formed by D6, C12 and R12, and the rectified DC signal is input through R11 after the voltage follower formed by the operational amplifier U4A Microcontroller (7). R8 and R9 of the voltage divider (5) sense the C-phase voltage, and its output signal is connected to the rectification circuit formed by D7, C13 and R17, and the rectified DC signal is input through R16 after the voltage follower formed by the operational amplifier U4B Microcontroller (7).

As shown in Figure 4a, the switching device (8) is controlled by the single-chip microcomputer (7) through R18, Q1 and relay K1, and the single-chip microcomputer (7) delays the setting time when the leakage current, load current or line voltage reaches or exceeds the action threshold Afterwards, a tripping command is issued to make the switching device (8) act, and the switching device (8) cuts off the fault circuit. Among them, the power circuit composed of D3, D4 and C11 supplies power to the tripping device, so as to ensure that the device can still complete the tripping action even under the condition of line power failure.

As shown in Figure 4a, the other secondary side of the zero-sequence current transformer RCT (1) forms a leakage simulation circuit (11) with the button S1 and the resistor R1. When S1 is pressed, the zero-sequence current transformer RCT (1) An analog leakage signal will be generated, and after the single-chip microcomputer (7) detects this signal, it will send a leakage protection command, that is, the single-chip microcomputer (7) outputs a high level, drives the relay K1 through R18 and Q1, and makes the switching device (8) act, It is used to check whether the leakage protection performance of the protector is normal.

As shown in Figure 4a, single-chip microcomputer U11 among the present invention (7) receives the signal after the signal conditioning circuit (6) amplifies and the signal of frequency detection circuit (15), controls button/display circuit (12), real-time clock circuit (13 ), external memory (14) and switching device (8). The single-chip microcomputer U11(7) analyzes and judges the sampling value, and its process and method are:

(a) When the leakage current reaches or exceeds the leakage action current threshold, the single-chip microcomputer (7) sends a trip command after delaying the set time to make the switch device (8) act, and the switch device (8) cuts off the fault circuit to make the fault leakage be protected.

(b) When the load current in the line reaches or exceeds the overcurrent protection action threshold, the single-chip microcomputer (7) sends a tripping command after delaying the set time to make the switch device (8) act, and the switch device (8) cuts off the fault circuit , so that the overload current is protected.

(c) When the line voltage is higher than the overvoltage protection action threshold or lower than the undervoltage protection action threshold, the single-chip microcomputer (7) sends a tripping command after delaying the set time to make the switch device (8) act, and the switch device (8) ) to cut off the fault circuit, so that the abnormal voltage is protected.

As shown in Figure 4a, the button/display circuit (12) is composed of U2, C5, C6, C7, C8, C9, DS1-DS25, S2-S7, S11, S12, R13, R14, R15, R19, R27, and The single-chip microcomputer (7) is connected and controlled by the single-chip microcomputer (7). The display circuit (12) cyclically displays the leakage current, load current and line voltage, and displays the leakage protection, overcurrent protection and abnormal voltage protection rated action value, action time, cause of action and fault value. Keyboard (12) is used for selecting rated action value, action time and query history record.

As shown in Figure 4a, the real-time clock circuit (13) is composed of U12, C18, C19, Y1, BT1 and C17, connected with the single-chip microcomputer (7) and controlled by the single-chip microcomputer (7). The real-time clock circuit (13) provides real-time time for the intelligent leakage comprehensive protector, which is used for fault records and operation history records, so that users can understand the operation status of the line in more detail.

As shown in Fig. 4a, the external memory U13 (14) is connected with the single-chip microcomputer (7) and controlled by the single-chip microcomputer (7). The external memory is used to regularly store leakage current, load current, line voltage and fault information during line operation, which is convenient for users to inquire.

As shown in Figure 4a, the frequency detection circuit (15) is composed of R29, D10, D11, and U8A. The grid frequency signal is shaped into a square wave and then input to the single-chip microcomputer (7) through R31. The single-chip microcomputer U11 (7) adopts an internal timer to control Power supply signal is carried out timing measurement, and when grid frequency changes, the timer value of single-chip microcomputer (7) also just changes, realizes the automatic tracking to grid frequency, makes the data that single-chip microcomputer (7) collects in the cycle when carrying out signal collection constant, reduces The error of data processing is reduced, and the measurement accuracy is improved.

As shown in Figure 4a, the power supply circuit (10) is composed of a transformer T1, diodes D1, D2, integrated voltage regulator U1, and C1, C2, C3, and C4. The voltage output by T1 is rectified by diodes D1, D2 and then output to U1 for further processing. Voltage stabilization, C1, C2, C3, and C4 filter the power supply. The power supply circuit (10) supplies power for the single-chip microcomputer and other circuits.

As shown in Figure 4b, the communication module (9) consists of an integrated circuit 1 (U15), an integrated circuit 2 (U7), an optocoupler (U5, U9, U10), an integrated module (U14), and a SIM card slot (U16) , R20, R21, R22, R25, R28, R33, R36, R54~R62, C27~C36, L2, L3, Y3, antenna RF ANT, D21, Q2 and Q3. Wherein: integrated circuit 1 (U15), R54, C27, C30, C31, C33, C34, C35, Y3 and antenna RF ANT form the wireless communication circuit of communication module (9); integrated circuit 2 (U7), optocoupler ( U5, U9, U10), R20, R21, R22, R25, R33, R36, R28 and Q2 constitute the wired communication circuit of the communication module (9); integrated module (U14), SIM card slot (U16), R55～R62 , C28, C29, C36, Q3 and D21 form the communication circuit based on the national public mobile communication network of the communication module (9). The communication module (9) is connected to the single-chip microcomputer (7) through the connection seat P1, and realizes the communication function under the control of the single-chip microcomputer (7): multiple intelligent leakage protection comprehensive protectors are connected to each other through their respective communication modules (9) to form a leakage protection monitoring network , this connection method can be a wired connection through the connection seat P2 of the communication module (9), or a wireless connection through the wireless communication circuit of the communication module (9). Each leakage integrated protector is a network node, and any network node can be used as the control center of the network to control the operation of the entire network, but the control center is unique at the same time; the control center is responsible for collecting the lines protected by each network node Real-time operation data and fault information, and also control the working status of network nodes. The control center establishes communication with the user's mobile phone or host computer through the communication circuit based on the national public mobile communication network (GSM, CDMA/CDMA2000, WCDMA, TDSCDMA), and informs the user The running status of the network nodes, the user can also view or modify the parameter settings of any node in the network through the mobile phone or the host computer, and can perform remote opening and closing operations through the mobile phone or the host computer.

Fig. 5 a shows that among the present invention, single-chip microcomputer realizes the operation program of protection function:

(1) After the single-chip microcomputer is powered on, initialize the registers and variables, and turn to step (2) after the initialization is completed;

(2) Collect the leakage current, phase A load current, phase B load current, phase C load current and line voltage signals according to the sampling frequency and window period; after completing a cycle of sampling, calculate the leakage current, three-phase load current and The value of the line voltage, after the calculation is completed, go to step (3);

(3) According to the magnitude of the leakage current just detected, judge whether the leakage current value is greater than or equal to the leakage action threshold. When the leakage current is greater than or equal to the leakage action threshold, it will enter the delay program, and the trip will be issued after the set time delay instruction; when the leakage current is less than the leakage action threshold, turn to step (4);

(4) According to the newly detected three-phase load current, judge whether the load current value of each phase is greater than or equal to the over-current action threshold. When the load current of a certain phase or several phases is greater than or equal to the over-current action threshold, transfer to delay Timing program, delay the set time and send out the trip command; when the three-phase load current is less than the over-current action threshold, go to step (5);

(5) According to the magnitude of the line voltage just detected, judge whether the voltage value of each phase is greater than or equal to the overvoltage action threshold. After the time is set, a trip command is issued; when the three-phase voltage is lower than the overvoltage action threshold, go to step (6);

(6) According to the magnitude of the line voltage just detected, judge whether the voltage value of each phase is less than or equal to the undervoltage action threshold. Send a trip command after the set time; when the three-phase voltage is greater than the undervoltage action threshold, turn to step (7);

(7) single-chip microcomputer waits for the trigger signal that next cycle sampling starts, once this trigger signal arrives, single-chip microcomputer promptly changes over to the sampling procedure of step (2) and carries out next cycle sampling;

Fig. 5 b shows that the single-chip microcomputer among the present invention realizes the operating procedure of communication sending function:

(1) Under the condition that no fault occurs in the line, the single-chip microcomputer periodically detects the state of the sending flag, and turns to (2) step when detecting that the sending flag is 1;

(2) the single-chip microcomputer loads the target address of the communication and the data content sent, and turns to the (3) step;

(3) The single-chip microcomputer automatically selects the communication method according to the connection status: first, judge whether the communication target address is the user's mobile phone, and if the communication target is the user's mobile phone, then select the communication mode based on the public mobile communication network (GSM, CDMA/CDMA2000, WCDMA, TDSCDMA) and transfer Go to step (4); if the communication target is not the user's mobile phone, then check whether the wired communication method is available, if available, then select the wired communication method and go to step (4); if the wired communication method is not available, then check the wireless communication Whether the method is available, if available, then select the wireless communication method and go to step (4); if the wireless communication method is still not available, then report to the user that there is a failure in the communication line;

(4) Use the selected communication method to send the communication data to the target address, and turn to step (1) after the data is sent.

Fig. 5c shows that the single-chip microcomputer among the present invention realizes the operating procedure of communication receiving function:

(1) Under the condition that no fault occurs in the line, the single-chip microcomputer periodically detects the state of the receiving flag, and turns to (2) step when detecting that the receiving flag is 1;

(2) Single-chip microcomputer scans whether there is data receiving under various communication modes successively: first scan whether there is data receiving under the communication mode based on public mobile communication network, if there is data receiving, then transfer to (3) step; If based on public mobile communication network If there is no data reception under the communication mode, scan whether there is data reception under the wired communication mode, if there is data reception, then go to step (3); if there is no data reception under the wired communication mode, then scan whether there is any Data reception, if there is data reception under the wireless communication mode, then go to step (3); if there is still no data reception under the wireless communication mode, then go to step (1);

(3) Receive the communication data packet, after the data packet is received, judge whether the communication address is the address of this machine, if it is, then go to step (4); if the communication address is not the address of the machine, then discard the communication data received And go to step (1);

(4) Process the received data packets, and turn to step (1) after the processing is completed.

What is not mentioned in the present invention is applicable to the prior art.

The above are only two embodiments proposed according to the technical solution of the present invention, and do not limit the present invention in any form. All simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention still fall within the scope of the claims of the present invention.

Claims (1)

1. leakage comprehensive protector is realized an operation method for booster action, it is characterized by described leakage comprehensive protector and comprises zero sequence current mutual inductor, A phase load current transformer, B phase load current transformer, C phase load current transformer, voltage divider, signal conditioning circuit, single-chip microcomputer, switching device, communication module and power supply; Wherein, the output of zero sequence current mutual inductor, A phase load current transformer, B phase load current transformer, C phase load current transformer and voltage divider is connected with signal conditioning circuit, and the output of signal conditioning circuit is connected with single-chip microcomputer; Switching device is connected with single-chip microcomputer; Communication module is connected with single-chip microcomputer; The input of power supply is connected with electrical network, and the output of power supply is connected with signal conditioning circuit, single-chip microcomputer and communication module;

Described switching device is air circuit or relay;

Described signal conditioning circuit is by leakage current signal modulate circuit, voltage signal conditioning circuit and load current signal conditioning circuit three partial function the electric circuit constitutes, wherein, leakage current signal modulate circuit consists of operational amplifier, resistor, capacitor, diode, the input of leakage current signal modulate circuit is connected with the output of zero sequence current mutual inductor, and the output of leakage current signal modulate circuit is connected with single-chip microcomputer; Voltage signal conditioning circuit is comprised of three identical parts of structure, they form by operational amplifier, resistor, capacitor and diode, for the treatment of the three-phase voltage signal of being inputted by voltage divider, the input of voltage signal conditioning circuit is connected with the output of voltage divider, and the output of voltage signal conditioning circuit is connected with single-chip microcomputer; Load current signal conditioning circuit is comprised of three identical parts of structure, they form by operational amplifier, resistor, capacitor and diode, for the treatment of the three-phase load current signal of being inputted by load current mutual-inductor, the input of load current signal conditioning circuit is connected with the output of A phase load current transformer, B phase load current transformer, C phase load current transformer respectively, and the output of load current signal conditioning circuit is connected with single-chip microcomputer;

Described communication module is by wireless communication line, wire communication circuit and the three partial function the electric circuit constitutes of the communicating circuit based on national public's mobile communication network, and wherein, wireless communication line is the modular circuit based on wireless telecommunications integrated circuit; Wire communication circuit is the modular circuit based on field bus technique; Communicating circuit based on national public's mobile communication network is the data transmission module that utilizes national public's mobile communication network;

Described national public's mobile communication network is the GSM public of country mobile communication network, the CDMA/CDMA2000 public of country mobile communication network, WCDMA country's public's mobile communication network or the TDSCDMA public of country mobile communication network;

Described leakage comprehensive protector also comprises following auxiliary part: electric leakage simulative generator, keyboard/display circuit, real time clock circuit, external memory storage and frequency detection circuit; These auxiliary parts are all connected with single-chip microcomputer with power supply;

Described leakage comprehensive protector is realized the operation method of booster action, comprises the following steps:

1) under the condition of the protection of single-chip microcomputer off-duty and communication function, single-chip microcomputer operation display update and keyboard scan program: single-chip microcomputer regularly by specified operating value, the operate time of leakage current, load current, line voltage distribution and earth leakage protective, overcurrent protection and electric voltage exception protection, cause that the reason of action and fault value deliver to display circuit, to upgrade displaying contents; After Data Update, whether single-chip microcomputer operation keyboard scan program, detect and have button to press, and when having button to press, single-chip microcomputer is carried out keystroke handling program, to complete, arranges and query function; After display update and keyboard scan program are finished, single-chip microcomputer returns in defence program;

2), under the condition of the protection of single-chip microcomputer off-duty and communication function, single-chip microcomputer operation real-time time refresh routine, regularly reads the real-time time that real time clock circuit provides, for failure logging and history run record; After real-time time upgrades, single-chip microcomputer returns in defence program;

3) under the condition of the protection of single-chip microcomputer off-duty and communication function, single-chip microcomputer operation storage program, at regular intervals, leakage current when just circuit is moved, load current, line voltage distribution store in external memory storage, after storage, single-chip microcomputer returns in defence program;

When line failure, single-chip microcomputer also moves storage program, and fault message is stored in external memory storage, to be stored after, single-chip microcomputer returns in defence program;

4) at frequency detection circuit, directly from electrical network, obtain AC signal and be shaped to square-wave signal input single-chip microcomputer through zero balancing circuit, before single-chip microcomputer running protection program, first running frequency trace routine, square-wave signal to input detects, and the signal of one-period is carried out to timing, detect the time of one-period, with realize mains frequency from motion tracking;

5) simulation of electric leakage simulative generator produces fault electric leakage; when pressing leak(age) test button, electric leakage simulative generator produces a simulated failure leakage current, when single-chip microcomputer detects this simulated failure electric leakage; send electric leakage dropout order, whether normal for checking protector work of the present invention.

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