RU2468484C2 - Device for transfer of energy and data by single-wire or double-wire line in electric equipment system of lifting or transport machine - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: device contains decoupling units of digital signals and supply voltage in combined line of supply and data exchange in on-board system of electric equipment fed by generator or accumulator. Devices of galvanic isolation of line, current limiters in line, voltage limiters between line wires, between line and machine mass, generator output voltage, supply voltage of component of electric equipment system or any combination of these protection devices are used in the device additionally. Supply voltage delivered by line may be constant or alternating. In the last case, the device contains adequate voltage converter and, if necessary, rectifiers in end points of line. Decoupling units of digital signals and supply voltage are made based on optoelectronic devices, capacitors or signal transformers, and device of galvanic isolation is made in the form of insulating voltage converters.

EFFECT: improving reliability of transfer of supply voltage and data signals upon load increase in the system.

13 cl, 1 dwg

Description

The invention relates to mechanical engineering and can be used in on-board monitoring, protection and control systems for hoisting cranes, hydraulic hoists, excavators, dump trucks, loaders, tractors, cars and other lifting and transporting machines.

A device for transmitting electrical energy and information signals in the electrical system of a crane, made in the form of separate wired communication lines [1].

The parallel exchange of information between the components of an electrical equipment system leads to an increase in the number of electrical communication lines in this system and to a decrease in its reliability.

It is also known a device for exchanging data in the electrical system of a lifting machine, containing two-wire cable bus and controllers of the serial CAN interface for transmitting and receiving information. The transmission of electrical energy between the components in this electrical system is carried out by additional wire communication lines [2].

The use of separate wires for transmitting information signals and supply voltage to various components of the electrical equipment system, as well as the complexity of the mechanisms for detecting and limiting errors when using the CAN protocol, complicates and reduces the reliability of the hardware of the electrical system.

Closest to the proposed one is a device for receiving and transmitting data on a DC power line, containing bi-directional blocks for decoupling digital signals and a supply voltage in a combined power line and exchanging information installed in the controllers (components) of the electrical system of the machine. Each isolation block contains a power switch and a diode-capacitor circuit or inductor, connected in series to the DC power line [3].

This device does not take into account that the negative outputs of individual components (modules, controllers) of electrical equipment connected to the structural elements of the machine (with its “mass”) can have different potentials due to the flow of large currents through them when powerful consumers are turned on. This can lead to the failure of the electrical system and to malfunctions when transmitting data on the line.

In the known device is also not provided for the operation of the electrical system without a battery. In particular, due to the lack of effective protection against overvoltages at the output of the generator and in the line that occur when disconnecting powerful loads. In addition, there is no protection of electrical equipment from improper connection of the communication line to its individual components.

The technical results to which the proposed technical solution is directed are:

- prevention of failure of the electrical equipment of the machine in the presence of a difference in electrical potentials at various points of the "mass" of the machine that occurs when a current of high-current loads flows along its structural elements;

- ensuring the protection of individual modules of electrical equipment from improper connection to them of the combined power and data lines;

- the elimination of distortion of data transmitted over the communication line, in the presence of a potential difference between the negative terminals of the power supply of the individual modules of the electrical equipment, caused by the flow of large current on the "mass" of the machine, for example, during electric start of the engine of the machine;

- providing the possibility of operation of the electrical equipment of the machine from the generator with the battery disconnected;

- reducing the requirements for the value of the electrical resistance of the "mass" of the machine used as a negative power wire in the electrical system, with a corresponding simplification of its layout;

- preventing the failure of the electrical equipment of the machine when disconnecting powerful loads, in particular, an electric starter or headlights of its working lighting.

The proposed device for transmitting energy and data through a single-wire or two-wire line in the electrical system of a lifting or transporting machine contains blocks for decoupling digital signals and supply voltage in a combined line for transmitting power (voltage) power and information signals installed in this line and / or in composite parts of the on-board electrical system receiving electric power from a generator driven by the engine of the machine and / or from the battery, and implementing the functions of role, protection, and / or control of the machine. In this device, the indicated technical results are achieved by the additional application of at least one of the following devices: a line isolation device, a current limiting device in a line, a voltage limiting device between the line wires, between the line and the “mass” of the machine, and voltage the output of the generator or the supply voltage of any module of the electrical equipment system received from the line, or any combination of these devices.

The supply voltage in the line can be either constant or variable, formed using an additional converter. In the latter case, the device may additionally contain one or more rectifiers installed at the end points of the line or in the receivers of the supply voltage (in modules or components of the electrical system) connected to this line.

The isolation blocks of digital signals and supply voltage in the line can be implemented using optoelectronic devices, capacitors or signal transformers. In the case of transmission of alternating current supply voltage through the line, blocks of this isolation can be implemented on the basis of technical means that modify or encode the operating frequency of the DC-DC voltage to alternating voltage supply, depending on the data to be transmitted over the line and subsequently detect this change or decoding the frequency at the data receiving point.

The galvanic isolation device of the line is preferably made in the form of an insulating voltage converter, in which, if necessary, the function of stabilizing its output voltage is implemented. Current limiters in the line can be made in the form of self-healing fuses made of polymer material, electronic fuses or voltage stabilizers with the function of overcurrent protection, and voltage limiters - in the form of varistors, limit diodes (suppressors), electronic voltage stabilizers or active filters.

In addition, to achieve the specified technical results, in any embodiment of the device:

- as the second wire or part of the second wire of the line can be used a metal element or structural elements of the machine (its "mass");

- between the wires of the line or between the wire (wires) of the line and the "mass" of the machine can be connected at least one capacitor, LC filter or RC filter. The choke or resistor of such a filter is connected in series in any wire of the line;

- a line may have a physical point-to-point topology or a star or tree network topology;

- galvanic isolation of the line, voltage and current limiters can be installed in the line, in the components of the on-board electrical system and / or autonomously.

Due to these distinctive features, the proposed device provides the transmission of supply voltage and information signals along a common line, regardless of the difference in electrical potentials of the minus (common) outputs of the individual components (modules) of the electrical system. This potential difference occurs during the operation of the system due to the flow of large amounts of current through the structural elements of the machine (by its "mass") when powerful loads are turned on. For example, during the electric start of a car engine.

The use of galvanic isolation of the negative supply wire between the individual modules of the electrical equipment system, including under conditions when the individual elements of these modules do not have galvanic isolation from the “mass” of the machine, is one of the essential features of the claimed technical solution, not known from the prior art.

Design features of the proposed device are also aimed at ensuring the operation of the electrical system of the machine without a battery. In particular, due to the protection of electrical equipment from overvoltages at the output of the generator that occur when disconnecting powerful loads. In addition, limiting the current in the line protects the electrical system from improperly connecting the communication line to its individual components (modules, blocks, etc.).

Therefore, the distinguishing features of the claimed technical solution, not known from the prior art, ensure the achievement of these technical results.

The drawing in a generalized form shows a diagram of a device for transmitting energy and data through a single-wire or two-wire line in the electrical system of the machine.

The on-board electrical system of a lifting or transporting machine that implements the control, protection and / or control functions of this machine, for example, the control and protection functions of a crane against overload, consists of individual components, which may be called modules, blocks, controllers, consoles, etc. .

In the drawing, as an example, modules 1, 2, 3 are shown, interconnected by two-wire 4 and single-wire 5 communication lines, through which the supply voltage (electrical energy) is transmitted to these modules and information (data) is exchanged between them.

A connection can be made using a physical point-to-point topology (between two modules) or using a star or tree network topology.

The electrical power supply of the modules (components) of the electrical system is carried out from a generator 6, which is driven by the engine of the machine, and / or from the battery 7. In the common power circuit, a device for switching and overcurrent protection, made in the form of a circuit breaker, fuse 8, etc. (may be absent), and also, if necessary, a device for protecting individual modules from connecting the battery 8 with reverse polarity. For example, diode 9.

Part of the electrical equipment system can be implemented using traditional lines of transmission of power energy and information signals to its individual components. For example, individual wires, CAN buses in combination with separate power buses, etc.

Control circuits 10, 11 of modules 1, 2, 3 can be made on the basis of microcontrollers or discrete components and, in the general case, contain electronic or electromechanical power switches designed to control loads 12, 13, 14, as well as matching circuits with a set of analog digital and discrete sensors of machine parameters (temperature, pressure, machine load, etc.), environmental parameters (ambient temperature, wind speed, etc.) and control actions of the driver. Separate sensors can be included in the modules.

These modules may also include controls for the system and the machine as a whole, display elements, etc.

Decoupling units for digital signals and supply voltage 15, 16 in a combined power and data exchange line 4, 5, as well as galvanic isolation devices 17, 18 and / or voltage limiting devices 19, 20, 21, 22 or current 23, 24, 25, 26, are installed in this line 4, 5 and / or in the component parts (modules) 1, 2, 3 of the on-board electrical system.

In justified cases, as the second wire or part of the second wire of line 5, individual metal elements of the machine structure (its “mass”) can be used,

The supply voltage in line 4, 5 can be either constant or variable. Accordingly, the galvanic isolation device 17, 18 is made on the basis of an isolating converter of DC to DC voltage, DC to AC, AC to AC or AC to AC.

If an alternating voltage is applied to any line 4, 5, then rectifiers can be installed at the output of this line, or in modules connected to it, (they are conventionally shown in the drawing). Moreover, if individual high-current loads Zн 13, 14 have small inductances (they are, for example, incandescent lamps) and can operate on AC voltage, rectifiers in the power supply circuits of the power parts of the modules are not installed. In this case, only low-current rectifiers are used to power control circuits 10, 11.

The isolation blocks of the digital signals and the supply voltage 15, 16 are implemented using optoelectronic devices, capacitors 27, 28, 29 or signal transformers. The transmission of digital signals between individual segments of the communication line 4, 5, separated by an insulating voltage converter 18, can be carried out, for example, using capacitors 30, 31, or full-featured isolation blocks.

Full-featured isolation blocks 15, 16 contain, in particular, voltage-converting amplifiers 32, 33 that implement the functions of receiving / transmitting digital signals, amplifying, regenerating, filtering, encoding / decoding and exchanging data with microcontrollers of control circuits 10, 11 of modules 1, 2.

Power to the isolated parts of isolation blocks 15, 16, if necessary, can be supplied either directly from the input and output of the isolating voltage converter 17, or through additional intermediate isolation converters (not shown).

When using an alternating voltage in line 4, 5, the isolation of digital signals and the supply voltage can be made in the form of means for changing or coding the operating frequency of the DC / AC converter depending on the data to be transmitted along the line, as well as means for detecting this changing or decoding the frequency at the data receiving point. In this case, an isolating converter 17, consisting of a frequency-controlled generator 34 and a transformer 35 (there is no rectifier 36 in this case), is controlled by a microcontroller of the control circuit 10, and the device 33 implements the functions of a frequency demodulator.

The voltage limiters at the output of the generator 19, between the wires of the line 20, as well as between the line and the "mass" of the machine 21 are made mainly in the form of varistors. For these purposes, restrictive diodes (suppressors) can also be used.

The output voltage limiter 22 is made in the form of an electronic voltage stabilizer or active surge filter, connected in series to line 5 at its output.

Current limiters are made in the form of self-healing fuses made of polymer material 23-26, electronic fuses or voltage stabilizers with overcurrent protection.

To enhance protection against interference, capacitors, LC-filters 37, 38 or RC-filters can be switched on between the line wires and / or between one wire of the line and the “mass” of the machine. In the latter case, the inductor 37 or the filter resistor is connected in series to the line wire. Due to energy losses on the resistor, the use of RC filters is justified only in modules with low current consumption.

In this case, the inductor 37, which prevents the capacitor 38 from blocking high-frequency information signals in line 5, is at the same time an integral part of the block for decoupling digital signals and the supply voltage 16.

Structurally, all of the listed protection and isolation components can be placed independently, inside modules 1, 2, 3 or on the line. For example, in the form of inserts in a line, including those made in the form of separate blocks 39, adapters, etc.

Any module of an electrical equipment system or a group of modules can contain its own multiplex communication line, for example, such as LIN, CAN, etc., connecting these modules into a separate group, which is not of fundamental importance.

Thus, as shown in the drawing, a device for transmitting energy and data along the line in the electrical system of the machine, according to the distinctive part of the claims, depending on the options for its implementation may contain:

- a device for galvanic isolation of the line (elements 18, 35);

- voltage limiter between the wires of the line (element 20);

- voltage limiter between the line and the "mass" of the machine (element 21);

- voltage limiter at the output of the generator (element 19);

- current limiter in the line (elements 23-26);

- limiter of the supply voltage of the component part of the electrical equipment coming from the line (element 22).

A device may contain one (any) of these elements, several elements in any combination, or all of the above elements at the same time.

If the device is implemented with missing elements 19, 20, 21, then their connection points remain free.

If elements 18, 22, 23, 24, 25, 26 and 35 are excluded from the device, then the points of their connection are interconnected (short-circuited). Moreover, for elements 18 and 35, such a connection is carried out in pairs.

The device operates as follows.

When the machine is running, the generator 6, having a drive from its engine, provides for recharging the battery 7 and is a source of energy for the electrical system. Its rated output voltage is, for example, +27 V DC.

The supply voltage through the switching device and overcurrent protection 8 is supplied to the master module 1, or simultaneously to several modules 1, 2, which can be equivalent. Further, this voltage through the protection device from connecting the battery with reverse polarity 9 (may be absent) and through an isolation converter 17, which provides galvanic isolation and, if necessary, stabilization of the supply voltage, enters line 4 and is then used to power other components (modules) electrical systems of the machine.

On hoisting and transporting machines, high-current elements of electrical equipment are often used, one of the terminals of which is connected to their body. When installing such elements (loads 12, 13, 14) on the machine, these conclusions are connected to the "mass" (structural elements) of the machine. When using this "mass" as a negative or "common" load supply wire, a serious problem arises due to the mismatch of the zero potentials of the "mass" at different points of the machine when high current loads are turned on. For example, during the electric start of a car engine.

In this case, parasitic circuits arise, along which "earth" currents of large magnitude begin to pass. Despite the relatively small electrical resistance of the structural metal elements (“mass”) of the machine, the flow of large currents of powerful loads causes interference and distortion in the transmission of information signals through communication lines, and with a large difference in ground potentials, it can lead to damage to individual electrical devices.

To eliminate the malfunction and failure of the electrical equipment of the machine from the flow of "earth" currents, galvanic isolation of the negative wire of the power line of the individual components of the electrical system is used. From the drawing it follows that in the proposed device, the current along the structural elements of the machine from the generator 6 and the battery 7 to the site of the "mass" of the machine 41 does not flow, despite the fact that both the generator with the battery and the load 14 are connected to the "mass of the machine ".

Communication line 4 is equipped with safety blocks, each of which includes a pair of self-healing fuses 23, 24 and 25, 26, as well as varistor 20, which are built into the two-wire data exchange line 4 and protect the electronic components (modules) of the system from failure in the presence of overvoltage, in case of damage to the line and its improper connection to the modules.

With a short circuit of the line, as well as with its incorrect connection to the modules, an increase in the current flowing through the self-healing fuses 23-26 occurs. In this case, there is a sharp increase in the resistances of self-healing fuses, which limits the current in the line and protects the electrical system. After eliminating the reasons for the increase in current, the electrical system automatically goes into working condition.

At the time of disconnection of powerful loads 12, 13, 14 at the output of the generator 6 there is an overvoltage pulse. This impulse, especially in the absence of the battery 7, is large and can lead to the failure of the electrical system. To reduce its amplitude, a varistor 19 is installed in the system. Additional varistors 20, 21, an output voltage limiter 22, and also isolating voltage converters 17, 18, if they are made with the stabilization function, provide additional protection for the individual components (modules) of the system from these overvoltages. output voltage.

Data transfer between the modules, necessary for the implementation of the control, protection and control functions of the machine, including for interrogating sensors, software microcontrollers for implementing control circuits 10, 11 of logical functions, load control 12, 13, 14, etc., is carried out in in general, in multiplexed mode.

Information and control signals between modules 1,2,3 are transmitted digitally in accordance with the serial interface selected for this system, which is implemented by microcontrollers of control circuits 10, 11.

Information signals (data) are transmitted on lines 4, 5 simultaneously with the transmission of power energy to the individual modules of the system.

In the block of isolation of digital signals and supply voltage 15, the input logical signals generated by the control circuit 10 are encoded by pulses of a certain duration, frequency, polarity and / or amplitude and then go to line 4, 5.

The pulses from line 5 are fed to decoding circuit 33, which restores the input signal. In this case, signal amplification, its regeneration, interference filtering, error detection and correction, etc. are carried out.

Similarly, data is transferred in the opposite direction.

When organizing this data exchange, control circuits 10, 11 before starting data transfer, receive signals from line 3, 4 and identify that the line is free to transmit data, form requests for data from each component (module) of the system or for information transfer to them . Each request contains, in particular, the address of the component of the system with which the exchange of information should take place, the command, information (when transmitting data) and the checksum.

The signal from line 4, 5 is fed simultaneously to the inputs of control circuits 10, 11 of all components of the system. They receive information from line 4, 5 and check the checksum. If the checksum does not match, the reception result is ignored and the control circuit 10, 11 switches to the standby mode for the next transmission, which is cyclically repeated in order to ensure the reliability of the system when operating in the presence of interference.

If the checksum matches, each control circuit 10, 11 compares the received address with its own address and, if they match, receives information and generates confirmation signals for this reception, or starts transmitting response information. In this case, other control circuits 10, 11 (modules 1, 2, 3), whose addresses do not coincide with the transmitted address, ignore the received request signal and are in standby mode for accessing them. Due to this, at any time in the transmission mode there is only one component of the system and there is no conflict over the loading of the combined power line and data exchange 4, 5.

In the electrical system, serial transmission of digital information can be implemented in both asynchronous and synchronous modes. In this case, various channel, network, transport, and application layers of the information transmission protocol can be implemented. In particular, the underlying access protocols for wired networks LIN, CAN, MicroLAN, etc., which is not critical.

In this description, only particular embodiments of the proposed device are schematically shown. The invention covers other possible variants of its execution and their equivalents without deviating from the essence of the invention set forth in its formula.

Information sources

1. RU 2129524 C1, B66C23 / 88, B66C13 / 18, 04/27/1999.

2. RU 2264973 C2, B66C15 / 06, 11.27.2005.

3. RU 2276094 C1, B66C13 / 18, B66C23 / 88, 05/10/2006.

Claims (13)

1. A device for transmitting energy and data through a single-wire or two-wire line in the electrical system of a lifting or transport machine, containing blocks for decoupling digital signals and supply voltage installed in this line and / or in the components of the on-board electrical system, configured to implement monitoring functions , and / or protection and / or control of the machine, characterized in that the electrical system receives power from a generator with a drive, from the engine of the machine or from the battery a, and further comprises a device for galvanic isolation of the line, a device for limiting the current in the line, a device for limiting the voltage between the wires of the line and the voltage between the line and the "mass" of the machine, a device for limiting the voltage at the output of the generator or the supply voltage of any module of the electrical equipment received from lines. 2. The device according to claim 1, characterized in that it further comprises a converter of direct current voltage, received from the generator and / or battery, into an alternating current voltage, the output of which is connected to the line. 3. The device according to claim 2, characterized in that it further comprises a rectifier installed at the end point of the line or in the receiver of the supply voltage, or at least in one of the end points of the branched line or in the receiver of the supply voltage connected to it. 4. The device according to claim 2, characterized in that the isolation blocks of the digital signals and the supply voltage of the alternating current in the line are made in the form of means for changing or encoding the operating frequency of the specified converter of the DC voltage to alternating voltage, depending on the data to be transmitted over the line as well as means for detecting this change or decoding the frequency at the data receiving point. 5. The device according to claim 1, characterized in that the decoupling unit for digital signals and the supply voltage is implemented using at least one optoelectronic device, or a capacitor, or a signal transformer, and the galvanic isolation device contains an insulating DC voltage converter built-in to the line current to DC voltage, or DC voltage to AC voltage, or AC voltage to DC voltage, or AC voltage and in AC voltage. 6. The device according to any one of paragraphs.2-5, characterized in that the voltage Converter is configured to stabilize its output voltage. 7. The device according to any one of claims 1 to 5, characterized in that the current limiter is made in the form of at least one self-healing or electronic fuse or voltage stabilizer with the function of overcurrent protection. 8. The device according to any one of claims 1 to 5, characterized in that at least one metal structural member of the machine is used as the second wire or part of the second wire of the line. 9. The device according to any one of claims 1 to 5, characterized in that the voltage limiter between the line wires, and / or the voltage limiter between the line and the "mass" of the machine, and / or the voltage limiter at the generator output is made in the form of a varistor or a limiting diode . 10. The device according to any one of claims 1 to 5, characterized in that the voltage limiter of the component of the electrical system is made in the form of an electronic voltage regulator or an active or passive filter, the power terminals of which are connected in series with the line. 11. The device according to any one of claims 1 to 5, characterized in that it further comprises at least one capacitor connected between the wires of the line and / or between one wire of the line and the "mass" of the machine, or at least one LC-filter or RC-filter, in which a choke or resistor is connected to one wire of the line, and the capacitor terminal is not connected to the choke or resistor, is connected to another wire of the line or to the "mass" of the machine. 12. The device according to any one of claims 1 to 5, characterized in that the line has a physical point-to-point topology or a star or tree network topology. 13. Device according to any one of claims 1 to 5, characterized in that at least one device for galvanic isolation of the line, and / or voltage limiter between the wires of the line, and / or voltage limiter between the line and the "mass" of the machine, and / or a voltage limiter at the output of the generator, and / or a limiter of the output supply voltage, and / or a current limiter in the line is installed / installed in this line, and / or autonomously, and / or in at least one component of the on-board electrical system .