CN114121549A - Relay synchronous control circuit and method for operating the same - Google Patents
Relay synchronous control circuit and method for operating the same Download PDFInfo
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- CN114121549A CN114121549A CN202111316262.5A CN202111316262A CN114121549A CN 114121549 A CN114121549 A CN 114121549A CN 202111316262 A CN202111316262 A CN 202111316262A CN 114121549 A CN114121549 A CN 114121549A
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H47/00—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current
- H01H47/001—Functional circuits, e.g. logic, sequencing, interlocking circuits
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Abstract
A relay synchronization control circuit and a method for operating the same are provided, the circuit includes a controllable current source, a plurality of relay circuits connected in parallel in two electrical networks, and a controller, wherein the controllable current source outputs an adjustable current to each of the plurality of relay circuits, the controller sends a control signal to the plurality of relay circuits and receives a signal fed back from the plurality of relay circuits, and controls the relay of the plurality of relay circuits to be turned on and off according to the feedback signal. According to the scheme of the invention, the conduction time difference of the two relays is detected in advance through the detection circuit, so that the two relays connected in parallel can act simultaneously, and the phenomenon that a single relay is firstly conducted to bear larger current and is burnt out can be avoided to a great extent.
Description
Technical Field
The invention relates to the field of intelligent control, in particular to a relay synchronous control circuit and a method for operating the same.
Background
With the rapid development of the industry in China, relays are also widely applied to various industrial fields to control the on-off of circuits, the requirements of different occasions on the relays are different, and different relays are selected according to the requirements of different occasions.
Sometimes, the current capacity of a single relay is insufficient in some occasions and cannot meet the power requirement, at the moment, in order to increase the current capacity of the relay, the same type of relay may be used in parallel, and then the same control signal is used for controlling the on-off of a plurality of relays. Theoretically, several relays can act simultaneously under the control of the same control signal, but in practice, even relays of the same type and the same model cannot act completely simultaneously, for example, the action time difference of two sets of contacts is usually 0.1ms-0.2ms, which may cause that the relay contact which is firstly conducted bears all current in a short time, and thus the relay is easily burnt.
Therefore, there is a need in the art for a solution that enables relays of the same type connected in parallel to operate simultaneously and that can prevent the relays from being burned out by an excessive current in a short time.
The above information disclosed in the background section is only for further understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.
Disclosure of Invention
The invention provides a relay synchronous control circuit and a method for operating the same. The scheme of the invention can solve the problem that the contacts of the relay which are connected in parallel are not synchronously operated, and can avoid the relay from being burnt by overlarge current in short time.
The invention provides a relay synchronous control circuit, which comprises a controllable current source, a plurality of relay circuits connected in parallel in two electrical networks and a controller, wherein the controllable current source outputs adjustable current to each relay circuit in the plurality of relay circuits, the controller sends control signals to the plurality of relay circuits and receives signals fed back by the plurality of relay circuits, and the relay in the plurality of relay circuits is controlled to be switched on and off according to the feedback signals.
According to an embodiment of the invention, each of the plurality of relay circuits comprises a relay, a current sensor, an optical coupler and an AD converter, the relay comprises two control ends and two main loop ends, wherein a first control end of the relay is grounded, a second control terminal is connected to the controller through the optical coupler to receive a control signal of the controller, the first main loop end of the relay is connected to a controllable current source, and a second main loop end of the relay, the current sensor and the AD converter are sequentially connected to feed back the signal after AD conversion to the controller.
According to an embodiment of the invention, the current sensor converts the detected circuit signal of the relay into an analog voltage signal, and the AD converter converts the analog voltage signal into a continuous data signal and feeds the continuous data signal back to the controller.
According to an embodiment of the present invention, the controller calculates a difference in conduction time between a plurality of relays in a plurality of relay circuits by the feedback signal, and adds the difference in conduction time to conduction signals of the plurality of relays to operate the plurality of relays simultaneously.
A second aspect of the present invention provides a method of operating a relay synchronization control circuit, the relay synchronization control circuit being the above circuit, the method comprising: providing a predetermined current to the plurality of relay circuits through the controllable current source prior to a high current on the plurality of relay circuits; the controller sends a conducting signal to a relay in each relay circuit to control the conduction of the relay; the controller compares feedback signals from the AD converters and calculates conduction time differences among relays in the plurality of relay circuits; controlling an operation of a relay in the plurality of relay circuits by the on-time difference.
According to an embodiment of the present invention, when the conduction time difference is smaller than or equal to a preset threshold, the output current of the controllable current source is set to zero, and the relays in the plurality of relay circuits are turned off, and when the network voltage connected to the plurality of relay circuits rises to a preset value, the conduction time difference is added to the relay conduction signals which need to be time-compensated to control the relays in the plurality of relay circuits to conduct.
According to one embodiment of the present invention, when the on-time difference is greater than a preset threshold, the output of the controllable current source is maintained at a preset current, and the relays in the plurality of relay circuits are turned off, and the on-time difference is added to the relay on signal requiring time compensation to control the relays to be turned on, and then the on-time difference between the relays in the plurality of relay circuits is re-detected until the on-time difference is less than or equal to the preset threshold.
The invention detects the conduction time difference of the two relays in advance through the detection circuit, thereby ensuring that the two relays connected in parallel can act simultaneously and avoiding that a single relay is firstly conducted to bear larger current to burn to a great extent.
Drawings
In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a block diagram of a prior art relay control circuit.
Fig. 2 is a block diagram of a relay synchronization control circuit according to an exemplary embodiment of the present invention.
Fig. 3 is a flowchart of a method of operating a relay synchronization control circuit according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION
As used herein, the terms "first," "second," and the like may be used to describe elements of exemplary embodiments of the invention. These terms are only used to distinguish one element from another element, and the inherent features or order of the corresponding elements and the like are not limited by the terms. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms, such as those defined in commonly used dictionaries, are to be interpreted as having a meaning that is consistent with their context in the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Those skilled in the art will understand that the devices and methods of the present invention described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the present invention is defined solely by the claims. Features illustrated or described in connection with one exemplary embodiment may be combined with features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention.
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, a detailed description of related known functions or configurations is omitted to avoid unnecessarily obscuring the technical points of the present invention. In addition, the same reference numerals refer to the same circuits, modules or units throughout the description, and repeated descriptions of the same circuits, modules or units are omitted for brevity.
Further, it should be understood that one or more of the following methods or aspects thereof may be performed by at least one control unit or controller. The terms "control unit," "controller," "control module," or "master module" may refer to a hardware device that includes a memory and a processor. The memory or computer-readable storage medium is configured to store program instructions, while the processor is specifically configured to execute the program instructions to perform one or more processes that will be described further below. Moreover, it is to be appreciated that the following methods may be performed by including a processor in conjunction with one or more other components, as will be appreciated by one of ordinary skill in the art.
The scheme of the invention can ensure that a plurality of relays act simultaneously by using a controllable current source to provide a small current for two relays connected in parallel before the high voltage, detecting the conduction time difference Tn of the relays by detecting the current in the relay loop and then adding the same compensation time Tn to the conduction signals of the relays.
Fig. 1 is a block diagram of a prior art relay control circuit.
As shown in fig. 1, a control circuit in which two relays are connected in parallel is shown, and in the control circuit in which the relays shown in fig. 1 are connected in parallel, two parallel relays are controlled to operate simultaneously by one signal. However, even if the same relay is used, the mechanical characteristics of the relay contacts are not completely the same, so that the simultaneous operation cannot be usually achieved, and the contact operations of the two relays have a certain time difference (0.1 ms-0.2 ms), which may cause the relay contacts which are firstly conducted to bear all current in a short time, and easily exceed the rated power of the relay to burn the relay.
In fig. 1, DC + and DCP are two different circuit networks, DC + is a DC bus network, and DCP is a DC bus network after passing through a relay, and the difference between them is: the DC + network has no energy storage capacitor, while the DCP network generally has an energy storage capacitor, and the two networks are connected together after the relay is closed.
Fig. 2 is a block diagram of a relay synchronization control circuit according to an exemplary embodiment of the present invention.
As shown in fig. 2, the circuit includes a controllable current source, an optocoupler, a current sensor, a sampling AD, a relay, a controller, and the like. The controller sends control signals to the relay circuits, receives signals fed back by the relay circuits, and controls the on and off of the relays in the relay circuits according to the feedback signals.
According to one or more embodiments of the present invention, each of the plurality of relay circuits includes a relay, a current sensor, an optical coupler, and an AD converter, the relay includes two control terminals and two main loop terminals, wherein a first control terminal of the relay is grounded, a second control terminal of the relay is connected to the controller through the optical coupler to receive a control signal of the controller, the first main loop terminal of the relay is connected to a controllable current source, and a second main loop terminal of the relay, the current sensor, and the AD converter are sequentially connected to feed back the signal after AD conversion to the controller.
Fig. 2 shows an example of two relays connected in parallel, and the relay synchronization control circuit of the present invention can be extended to a plurality of relay control circuits connected in parallel.
In fig. 2, the functions of the respective functional modules are:
optical coupling: the optical coupler only plays the roles of transmitting control signals and isolating, the front end of the optical coupler is connected with the control signals output by the main control board, and the rear end of the optical coupler is connected with one of coil pins of the relay. Since there is no high requirement for transmission delay, transmission rate, etc., an opto-coupler such as PC817, etc. with simple function and relatively low cost is generally selected.
Controllable current source: based on a 24V power supply current source with adjustable output current, the output of the current source is connected with a loop where two relay contacts are located, and a small current is provided for the loop for detecting the conduction time difference.
A current sensor: and when the relay is switched on, the current of a relay contact loop is detected, and the time of collecting the current is taken as the switching-on time of the relay.
Sampling AD: the current sensor converts the current signal into a voltage signal to be output, and then converts the analog voltage signal into a digital signal through AD sampling to be transmitted to a main control board (such as AD 7403).
A relay: when the signal of the control terminal is high level, the coil in the relay is electrified and then becomes an electromagnet to attract the switch of the main loop, and at the moment, the two terminals of the main loop are switched on; on the contrary, the control signal is low level, the coil is not powered, and the two terminals of the main loop 2 are disconnected.
Fig. 3 is a flowchart of a method of operating a relay synchronization control circuit according to an exemplary embodiment of the present invention.
As shown in fig. 3, a predetermined current is supplied to the plurality of relay circuits through the controllable current source before a strong current is applied to the plurality of relay circuits; the controller sends a conducting signal to a relay in each relay circuit to control the conduction of the relay; the controller compares feedback signals from the AD converters and calculates conduction time differences among relays in the plurality of relay circuits; controlling an operation of a relay in the plurality of relay circuits by the on-time difference.
According to one or more embodiments of the invention, when the conduction time difference is smaller than or equal to a preset threshold value, the output current of the controllable current source is set to be zero, the relays in the plurality of relay circuits are closed, and when the network voltage connected with the plurality of relay circuits is increased to a preset value, the conduction time difference is added to the relay conduction signals needing time compensation to control the relays in the plurality of relay circuits to be conducted.
According to one or more embodiments of the present invention, when the conduction time difference is greater than a preset threshold, the preset current of the output of the controllable current source is maintained, and the relays in the plurality of relay circuits are turned off, and the conduction time difference is added to the relay conduction signal requiring time compensation to control the conduction of the relays, and then the conduction time difference between the relays in the plurality of relay circuits is re-detected until the conduction time difference is less than or equal to the preset threshold.
As shown in FIG. 3, before the upper 220V/380V strong current, a small current is provided to the two relays through the controllable current source, and the main control board simultaneously sends two conducting signals to control the two relays to be simultaneously conducted. At this moment, the contact point loop of the relay has current (namely, a main loop, namely, two terminals connecting DC + and the current sensor), the current sensor converts the detected current signal into an analog voltage signal, then the analog voltage signal is converted into continuous data flow through an AD chip, and the time of collecting the first data is taken as the conduction time of the relay by the main control board, so that the conduction time difference Tn of the two relays can be obtained.
As shown in fig. 3, if Tn <50us (which can be set according to actual requirements), the output of the controllable current source can be adjusted to 0, then the two relays are turned off, and after the bus voltage rises to a set value, the compensation time of Tn can be added to the turn-on signal of the relay K1 to control the two relays to be turned on; if Tn is larger than or equal to 50us, the current source is kept to output a small current, the two relays are turned off firstly, the compensation time Tn is added to the conducting signal of the relay K1, then the two relays are controlled to be turned on, then the conducting time difference Tn of the two relays is detected again, and the steps are repeated until the required requirements are met if the conducting time difference Tn of the two relays is not met.
According to one or more embodiments of the present invention, assuming that the difference between the on-times of the two relays is within 50us to meet the requirement, the adjustment is stopped when Tn <50us is determined, that is, the controllable current source does not output, the relays are turned off, and Tn may be 10us or 20us, and the time is set according to the actual operation requirement.
In accordance with one or more embodiments of the present invention, control logic in methods of the present invention may implement processes such as the flows of the above methods of the present invention using encoded instructions (e.g., computer and/or machine readable instructions) stored on a non-transitory computer and/or machine readable medium (e.g., a hard disk drive, a flash memory, a read-only memory, an optical disk, a digital versatile disk, a cache, a random-access memory, and/or any other storage device or storage disk) in which information is stored for any period of time (e.g., for extended periods of time, permanent, transitory instances, temporary caches, and/or information caches). As used herein, the term "non-transitory computer-readable medium" is expressly defined to include any type of computer-readable storage device and/or storage disk and to exclude propagating signals and to exclude transmission media.
In accordance with one or more embodiments of the present invention, the method of the present invention may be implemented using control circuitry, (control logic, a master control system or control module), which may include one or more processors, or which may internally include a non-transitory computer-readable medium. In particular, the master control system or control module may comprise a microcontroller MCU. The processor implementing the processes of the present method may be such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and special-purpose processors (e.g., graphics processors, application processors, etc.). The processor may be coupled thereto and/or may include a memory/storage device and may be configured to execute instructions stored in the memory/storage device to implement various applications and/or operating systems running on the controller in accordance with the present invention.
The drawings referred to above and the detailed description of the invention, which are exemplary of the invention, serve to explain the invention without limiting the meaning or scope of the invention as described in the claims. Accordingly, modifications may be readily made by those skilled in the art from the foregoing description. Further, those skilled in the art may delete some of the constituent elements described herein without deteriorating the performance, or may add other constituent elements to improve the performance. Further, the order of the steps of the methods described herein may be varied by one skilled in the art depending on the environment of the process or apparatus. Therefore, the scope of the present invention should be determined not by the embodiments described above but by the claims and their equivalents.
While the invention has been described in connection with what is presently considered to be practical embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
Claims (7)
1. A synchronous control circuit for a relay, said circuit comprising a controllable current source, a plurality of relay circuits connected in parallel in two electrical networks, and a controller,
the controllable current source outputs an adjustable current to each of the plurality of relay circuits,
the controller sends control signals to the relay circuits, receives signals fed back by the relay circuits, and controls the on and off of the relays in the relay circuits according to the feedback signals.
2. The circuit of claim 1, wherein each of the plurality of relay circuits comprises a relay comprising two control terminals and two main loop terminals, a current sensor, an optocoupler, and an AD converter, wherein the relay comprises two control terminals and two main loop terminals
The first control end of relay ground connection, second control terminal is connected to through the opto-coupler the control signal of controller in order to receive the controller, the first major loop end of relay is connected to controllable current source, the second major loop end of relay, current sensor, AD converter connect gradually, will feed back to the controller through the signal after the AD conversion.
3. The circuit of claim 2, wherein the current sensor converts the detected circuit signal of the relay into an analog voltage signal, and the AD converter converts the analog voltage signal into a continuous data signal and feeds back to the controller.
4. The circuit of claim 1, wherein the controller calculates a conduction time difference between a plurality of relays in a plurality of relay circuits from the feedback signal and adds the conduction time difference to conduction signals of the plurality of relays to operate the plurality of relays simultaneously.
5. A method of operating a relay synchronization control circuit, the relay synchronization control circuit being a circuit according to any one of claims 1-4, the method comprising:
providing a predetermined current to the plurality of relay circuits through the controllable current source prior to a high current on the plurality of relay circuits;
the controller sends a conducting signal to a relay in each relay circuit to control the conduction of the relay;
the controller compares feedback signals from the AD converters and calculates conduction time differences among relays in the plurality of relay circuits; controlling an operation of a relay in the plurality of relay circuits by the on-time difference.
6. The method of claim 5, wherein the output current of the controllable current source is set to zero and the relays of the plurality of relay circuits are turned off when the conduction time difference is less than or equal to a preset threshold, and the conduction time difference is added to the relay conduction signals that need to be time compensated to control the conduction of the relays of the plurality of relay circuits when the network voltage to which the plurality of relay circuits are connected rises to the preset value.
7. The method of claim 5, wherein when the on-time difference is greater than a predetermined threshold, maintaining a predetermined current at the output of the controllable current source, and turning off the relays in the plurality of relay circuits, and adding the on-time difference to the relay on signal requiring time compensation to control the relays to turn on, and then re-detecting the on-time difference between the relays in the plurality of relay circuits until the on-time difference is less than or equal to the predetermined threshold.
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| CN202111316262.5A CN114121549B (en) | 2021-11-08 | 2021-11-08 | Relay synchronous control circuit and method for operating the same |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202111316262.5A CN114121549B (en) | 2021-11-08 | 2021-11-08 | Relay synchronous control circuit and method for operating the same |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02199726A (en) * | 1989-01-27 | 1990-08-08 | Matsushita Electric Ind Co Ltd | Relay drive device |
| CN104977528A (en) * | 2014-04-11 | 2015-10-14 | 华北电力大学 | Magnetic latching relay actuation time and reset time detection device |
| CN106374507A (en) * | 2016-09-06 | 2017-02-01 | 青岛鼎信通讯股份有限公司 | Three-phase common compensation intelligent synchronous switch and control protection method thereof |
| CN108987185A (en) * | 2018-07-23 | 2018-12-11 | 深圳市智维兴科技有限公司 | A kind of multi-channel DC relay conducting control technology |
| CN109003863A (en) * | 2018-08-13 | 2018-12-14 | 重庆明斯克电气有限公司 | Synchronous switch magnetic latching relay actuation time error auto compensatng method |
-
2021
- 2021-11-08 CN CN202111316262.5A patent/CN114121549B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02199726A (en) * | 1989-01-27 | 1990-08-08 | Matsushita Electric Ind Co Ltd | Relay drive device |
| CN104977528A (en) * | 2014-04-11 | 2015-10-14 | 华北电力大学 | Magnetic latching relay actuation time and reset time detection device |
| CN106374507A (en) * | 2016-09-06 | 2017-02-01 | 青岛鼎信通讯股份有限公司 | Three-phase common compensation intelligent synchronous switch and control protection method thereof |
| CN108987185A (en) * | 2018-07-23 | 2018-12-11 | 深圳市智维兴科技有限公司 | A kind of multi-channel DC relay conducting control technology |
| CN109003863A (en) * | 2018-08-13 | 2018-12-14 | 重庆明斯克电气有限公司 | Synchronous switch magnetic latching relay actuation time error auto compensatng method |
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