A relay detection circuit and energy storage power supply

Abstract

The application relates to the technical field of power control, and mainly provides a relay detection circuit and an energy storage power supply, which comprises a driving module connected with a relay coil end, a sampling module connected with a relay input end and an output end respectively, a comparison control module connected with the sampling module, and a controller connected with the comparison control module and the driving module. The driving module is used for driving the coil end of the relay to be electrified according to a driving signal output by the controller, and the sampling module is used for collecting input voltage and output voltage of the relay; the comparison control module is used for outputting a closing detection signal to the controller when a voltage difference between the input voltage and the output voltage is less than a preset threshold value, so that the controller can accurately calculate the actual attraction time of the relay in combination with a driving signal issuing time and a closing detection signal receiving time, the relay can be ensured to be closed at a zero-crossing point, the influence of an impact current on the relay is avoided, and the safety and reliability of the circuit are improved.

Description

Technical Field

[0001] This invention relates to the field of power control technology, and in particular to a relay detection circuit and an energy storage power supply. Background Technology

[0002] In AC power systems, smart power distribution, and reactive power compensation scenarios, relays are core actuators. To avoid inrush current and contact erosion during closing, the industry generally adopts zero-crossing switching technology, which uses software to control the drive signal so that the relay is activated at the AC zero-crossing point to achieve safe switching with low wear.

[0003] However, in existing technologies, there is an inherent delay between the transmission of the drive signal and the mechanical engagement of the relay, which makes it impossible for the software to accurately match the actual closing time. This can easily cause the closing point to deviate from the zero-crossing point, or even cause strong impacts when the relay is applied in a high-current range, thus shortening the life of the relay. Furthermore, when the relay contacts are damaged, such as by burning or semi-conducting, the voltage difference across the relay is extremely small. The existing simple sampling circuit is not accurate enough to effectively distinguish between the fully closed and semi-conducting states, which can easily cause system misjudgment and safety hazards such as overheating and welding, making it difficult to meet the requirements of high-reliability control.

[0004] Therefore, in order to solve the above problems, it is necessary to propose a relay detection circuit. Summary of the Invention

[0005] The present invention provides a relay detection circuit and an energy storage power supply, which aims to solve the technical problems in the prior art where the relay cannot close accurately at the zero crossing point, resulting in large circuit current surges, short lifespan, and low safety.

[0006] To solve the above-mentioned technical problems, one technical solution adopted in the embodiments of the present invention is to provide a relay detection circuit, the relay detection circuit including a driving module, a sampling module, a comparison control module and a controller; The driving module is connected to the coil terminal of the relay, the sampling module is connected to the input terminal and the output terminal of the relay respectively, the comparison control module is connected to the sampling module, and both the comparison control module and the driving module are connected to the controller. The drive module is used to receive the drive signal output by the controller and start working according to the drive signal to drive the coil terminal of the relay to be energized; The sampling module is used to collect the input voltage at the input terminal and the output voltage at the output terminal of the relay; The comparison control module is used to output a closure detection signal to the controller when the voltage difference between the input voltage and the output voltage is less than a preset threshold, so that the controller can determine the closing time of the relay based on the time of outputting the drive signal and the time of receiving the closure detection signal.

[0007] Optionally, the comparison control module is further configured to output a first comparison signal when the voltage difference between the input voltage and the output voltage is less than the preset threshold, and to output the closure detection signal based on the input voltage and the first comparison signal.

[0008] Optionally, the comparison control module includes a first comparison unit, a second comparison unit, and a logic unit; The first comparison unit is connected to the sampling module and the logic unit respectively, the second comparison unit is connected to the sampling module and the logic unit respectively, and the logic unit is also connected to the controller; The first comparison unit is configured to output a first comparison signal when the voltage difference between the input voltage and the output voltage is less than the preset threshold; and When the voltage difference between the input voltage and the output voltage is greater than or equal to the preset threshold, a second comparison signal is output; The second comparison unit is used to output a third comparison signal based on the input voltage; The logic unit is configured to output the closure detection signal upon receiving the first comparison signal and the third comparison signal; and Upon receiving the second comparison signal and the third comparison signal, a disconnection detection signal is output.

[0009] Optionally, the first comparison signal is a high-level signal, the second comparison signal includes complementary first pulse signals and second pulse signals, and the third comparison signal includes complementary third pulse signals and fourth pulse signals, wherein the first pulse signal and the third pulse signal have the same timing, and the second pulse signal and the fourth pulse signal have the same timing. The logic unit includes AND gate U6D, AND gate U9D and OR gate U10A; The two input terminals of AND gate U6D are respectively connected to the first comparison unit and the second comparison unit, the output terminal of AND gate U6D is connected to the first input terminal of OR gate U10A, the two input terminals of AND gate U9D are respectively connected to the first comparison unit and the second comparison unit, the output terminal of AND gate U9D is connected to the second input terminal of OR gate U10A, and the output terminal of OR gate U10A is connected to the controller. The AND gates U6D and U9D are used to output complementary fifth and sixth pulse signals to the OR gate U10A upon receiving the first comparison signal and the third comparison signal, so that the OR gate U10A outputs a closure detection signal; and Upon receiving the second comparison signal and the third comparison signal, both output a low-level signal to the OR gate U10A, so that the OR gate U10A outputs the disconnection detection signal.

[0010] Optionally, the logic unit further includes a resistor R251, a capacitor C96, a resistor R211, and a capacitor C34; The resistor R251 is connected to the output terminal of the AND gate U6D and the first input terminal of the OR gate U10A respectively. The resistor R251 is also grounded through the capacitor C96. The resistor R211 is connected to the output terminal of the AND gate U9D and the second input terminal of the OR gate U10A respectively. The resistor R211 is also grounded through the capacitor C34.

[0011] Optionally, the first comparison unit includes an operational amplifier U3B, a comparator U5B, a comparator U8B, a resistor R252, a resistor R255, a capacitor C84, and a capacitor C101. Both input terminals of the operational amplifier U3B are connected to the sampling module. The first input terminal of the operational amplifier U3B is also grounded through the resistor R252. The capacitor C84 is connected in parallel with the resistor R252. The second input terminal of the operational amplifier U3B is also connected to the output terminal of the operational amplifier U3B through the resistor R255. The capacitor C101 is connected in parallel with the resistor R255. The output terminal of the operational amplifier U3B is also connected to the first input terminal of the comparator U5B and the second input terminal of the comparator U8B, respectively. The second input terminal of the comparator U5B is connected to the ground terminal. The first input terminal of the comparator U8B is connected to the reference power supply. The output terminals of the comparators U5B and U8B are also connected to the logic unit.

[0012] Optionally, the first comparison unit further includes a bias sub-unit, wherein the bias sub-unit is a bidirectional diode D33; The first terminal of the bidirectional diode D33 is connected to the ground terminal, the second terminal of the bidirectional diode D33 is connected to the reference power supply, and the third terminal of the bidirectional diode D33 is connected to the output terminal of the operational amplifier U3B.

[0013] Optionally, the second comparison unit includes comparator U4B and comparator U7B; The first input terminal of comparator U4B and the second input terminal of comparator U7B are both connected to the sampling module. The second input terminal of comparator U4B and the first input terminal of comparator U7B are both connected to the reference power supply. The output terminals of comparator U4B and comparator U7B are also connected to the logic unit.

[0014] Optionally, the sampling module includes a first differential sampling unit and a second differential sampling unit; The first differential sampling unit is connected to the input terminal of the relay, and the second differential sampling unit is connected to the output terminal of the relay. Both the first differential sampling unit and the second differential sampling unit are also connected to the comparison control module. The first differential sampling unit is used to acquire the input voltage at the input terminal of the relay, amplify the input voltage, and output the amplified input voltage to the comparison control module; The second differential sampling unit is used to collect the output voltage of the relay's output terminal, amplify the output voltage, and output the amplified output voltage to the comparison control module.

[0015] To solve the above-mentioned technical problems, another technical solution adopted in the embodiments of the present invention is: to provide an energy storage power source, the energy storage power source comprising: Relays; and The relay detection circuit described above.

[0016] Unlike related technologies, the present invention provides a relay detection circuit and an energy storage power supply. The relay detection circuit includes a driving module, a sampling module, a comparison control module, and a controller. The driving module is connected to the coil terminal of the relay. The sampling module is connected to the input terminal and the output terminal of the relay, respectively. The comparison control module is connected to the sampling module. Both the comparison control module and the driving module are also connected to the controller. The driving module receives the driving signal output by the controller and starts working according to the driving signal to energize the coil terminal of the relay. The sampling module collects the input voltage at the input terminal and the output voltage at the output terminal of the relay. The comparison control module outputs a closure detection signal to the controller when the voltage difference between the input voltage and the output voltage is less than a preset threshold. This allows for accurate determination of the contact open / closed state using the voltage difference between the two ends, improving the accuracy of relay operating state identification. The controller can accurately calculate the actual closing time of the relay by combining the timing of the driving signal issuance and the timing of the closure detection signal receipt, effectively calibrating the inherent delay caused by the transmission of the driving signal and mechanical action, ensuring that the relay can close accurately at the zero-crossing point, thereby avoiding the influence of inrush current on the relay and improving the safety and reliability of the circuit. Attached Figure Description

[0017] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0018] Figure 1 This is a schematic diagram of an application scenario of an energy storage power source provided in an embodiment of the present invention; Figure 2 This is a structural block diagram of a relay detection circuit provided in an embodiment of the present invention; Figure 3 This is a circuit diagram of a relay detection circuit provided in an embodiment of the present invention; Figure 4 This is a circuit diagram of another relay detection circuit provided in an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] It should be noted that, unless otherwise specified, the various features in the embodiments of the present invention can be combined with each other, and all are within the protection scope of the present invention. Furthermore, although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different module division or in a different order than that shown in the device schematic diagram or the flowchart.

[0021] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0022] Please see Figure 1 , Figure 1 This is a schematic diagram illustrating an application scenario of an energy storage power source provided in an embodiment of the present invention, such as... Figure 1 As shown, the application scenario 1 includes a power supply 100, an energy storage power supply 200, and a load 300. The energy storage power supply 200 is connected to the power supply 100 and the load 300 respectively. The energy storage power supply 200 is used to receive the power supply voltage output by the power supply 100 and transmit the power supply voltage to the load 300 to supply power to the load 300.

[0023] Among them, such as Figure 1 As shown, the energy storage power supply 200 includes a relay 10 and a relay detection circuit 20. The relay 10 is connected to the relay detection circuit 20, the input terminal of the relay 10 is connected to the power supply 100, and the output terminal of the relay 10 is connected to the load 300. The relay detection circuit 20 outputs a closed signal to the coil terminal of the relay 10. When the coil terminal of the relay 10 receives the closed signal, it starts to work based on the closed signal, thereby transmitting the power supply voltage at the input terminal to the output terminal to supply power to the load 300.

[0024] However, when the relay 10 closes based on the closing signal, there may be a delay, causing the relay 10 to deviate from the zero-crossing point, which can easily damage the relay 10. Therefore, this application introduces a relay detection circuit 20. When the relay detection circuit 20 outputs a closing signal, it also acquires the first time the closing signal is output. Simultaneously, the relay detection circuit 20 also detects the input voltage at the input terminal and the output voltage at the output terminal of the relay 10 in real time, and determines the second time when the relay 10 actually closes based on the input and output voltages. After obtaining the first and second times, the closing time of the relay 10 after receiving the closing signal can be determined. At this time, the timing of outputting the closing signal is set according to the closing time of the relay 10, thereby ensuring that the relay 10 can close at the zero-crossing point after receiving the closing signal, thus improving the service life of the relay 10.

[0025] In some embodiments, the power supply 100 may be an AC power supply such as mains power or power grid, or a DC power supply such as an energy storage power supply or battery, and there is no limitation on this.

[0026] In some embodiments, please refer to Figure 2 , Figure 2 This is a structural block diagram of a relay detection circuit provided in an embodiment of the present invention, such as... Figure 2 As shown, the relay detection circuit 20 includes a drive module 21, a sampling module 22, a comparison control module 23, and a controller 24; The driving module 21 is connected to the coil terminal of the relay 10, the sampling module 22 is connected to the input terminal and the output terminal of the relay 10 respectively, the comparison control module 23 is connected to the sampling module 22, and both the comparison control module 23 and the driving module 21 are connected to the controller 24. The drive module 21 is used to receive the drive signal output by the controller 24 and start working according to the drive signal to drive the coil terminal of the relay 10 to be energized; The sampling module 22 is used to collect the input voltage at the input terminal and the output voltage at the output terminal of the relay 10; The comparison control module 23 is used to output a closure detection signal to the controller 24 when the voltage difference between the input voltage and the output voltage is less than a preset threshold, so that the controller 24 determines the closing time of the relay 10 based on the time of outputting the drive signal and the time of receiving the closure detection signal.

[0027] Specifically, when the energy storage power supply 200 starts working, the controller 24 outputs a drive signal to the drive module 21, causing the drive module 21 to start working based on the drive signal. The controller 24 records the time of outputting the drive signal. After the drive module 21 starts working, it outputs a closing signal to the coil terminal of the relay 10, causing the relay 10 to close based on the closing signal. When the relay 10 closes, the input voltage at the input terminal of the relay 10 is transmitted to the output terminal of the relay 10 through the connection terminal of the relay 10, thereby supplying power to the load 300.

[0028] When the energy storage power supply 200 starts working, the sampling module 22 also collects the input voltage at the input terminal and the output voltage at the output terminal of the relay 10 in real time, and outputs the collected input and output voltages to the comparison control module 23. After receiving the input and output voltages, the comparison control module 23 determines the difference between the input and output voltages. When the difference is less than a preset threshold, it determines that the relay 10 has closed, and at this time, the comparison control module 23 outputs a closure detection signal to the controller 24. After receiving the closure detection signal, the controller 24 determines the time of receiving the closure detection signal and determines the pull-in time of the relay 10 based on the time of outputting the drive signal and the time of receiving the closure detection signal. After determining the pull-in time of the relay 10, the time of outputting the drive signal can be determined, so that the relay 10 can pull in at the zero-crossing point when it receives the drive signal again, thereby reducing current surges, improving the service life of the relay, and thus improving the reliability of the energy storage power supply.

[0029] It is known that the sampling module 22 will collect the input voltage and output voltage of the relay 10 in real time. When the relay 10 is not closed, the input voltage of the relay 10 will be greater than the output voltage. At this time, the voltage difference between the input voltage and the output voltage received by the comparison control module 23 will be greater than or equal to the preset threshold, and the comparison control module 23 will not output the closure detection signal.

[0030] It should be noted that when the relay 10 closes, there is not only an inherent delay in mechanical engagement, but also a delay in the transmission of the drive signal. Therefore, by acquiring the time when the controller 24 outputs the drive signal and the time when the controller 24 receives the closing detection signal, the engagement time of the relay 10 can be accurately determined, enabling the relay 10 to engage accurately at the zero-crossing point. This not only improves the service life of the relay 10, but also enhances the safety of the energy storage power supply.

[0031] In some embodiments, the comparison control module 23 is further configured to output a first comparison signal when the voltage difference between the input voltage and the output voltage is less than the preset threshold, and to output the closure detection signal based on the input voltage and the first comparison signal.

[0032] Specifically, when the comparison control module 23 determines that the voltage difference between the input voltage and the output voltage is less than the preset threshold, the comparison control module 23 will output a first comparison signal. At the same time, the comparison control module 23 will also output the closure detection signal to the controller 24 based on the received input voltage and the first comparison signal, so that the controller 24 can determine the closing time of the relay 10.

[0033] In yet another embodiment, such as Figure 2 As shown, the comparison control module 23 includes a first comparison unit 231, a second comparison unit 232, and a logic unit 233; The first comparison unit 231 is connected to the sampling module 22 and the logic unit 233 respectively, the second comparison unit 232 is connected to the sampling module 22 and the logic unit 233 respectively, and the logic unit 233 is also connected to the controller 24; The first comparison unit 231 is configured to output a first comparison signal when the voltage difference between the input voltage and the output voltage is less than the preset threshold; and When the voltage difference between the input voltage and the output voltage is greater than or equal to the preset threshold, a second comparison signal is output; The second comparison unit 232 is used to output a third comparison signal based on the input voltage; The logic unit 233 is configured to output the closure detection signal upon receiving the first comparison signal and the third comparison signal; and Upon receiving the second comparison signal and the third comparison signal, a disconnection detection signal is output.

[0034] Specifically, after the sampling module 22 acquires the input voltage and output voltage of the relay 10, on the one hand, the sampling module 22 inputs both the acquired input voltage and output voltage to the first comparison unit 231; when the first comparison unit 231 receives the input voltage and the output voltage, it compares whether the difference between the input voltage and the output voltage is less than a preset threshold. When the difference between the input voltage and the output voltage is less than the preset threshold, the first comparison unit 231 outputs a first comparison signal to the logic unit 233; and when the difference between the input voltage and the output voltage is greater than or equal to the preset threshold, the first comparison unit 231 outputs a second comparison signal to the logic unit 233. On the other hand, the sampling module 22 directly outputs the input voltage to the second comparison unit 232, and when the second comparison unit 232 receives the input voltage, it outputs a third comparison signal to the logic unit 233 based on the input voltage.

[0035] When the logic unit 233 receives the first comparison signal and the third comparison signal, it considers the relay 10 to be closed. At this time, the logic unit 233 outputs a closure detection signal to the controller 24 so that the controller 24 can determine the time of receiving the closure detection signal. Conversely, if the logic unit 233 receives the second comparison signal and the third comparison signal, it considers the relay 10 not yet closed. At this time, the logic unit 233 outputs a disconnection detection signal so that the controller 24 can determine that the relay 10 is not yet closed. Based on this, the engagement time of the relay 10 can be determined by the time of receiving the closure detection signal and the time of outputting the drive signal, thereby changing the timing of outputting the drive signal so that the relay 10 can engage at the zero-crossing point, thus improving the reliability of the energy storage power supply.

[0036] It should be noted that the first comparison signal is a high-level signal, the second comparison signal includes complementary first pulse signals and second pulse signals, and the third comparison signal includes complementary third pulse signals and fourth pulse signals, wherein the first pulse signal and the third pulse signal have the same timing, and the second pulse signal and the fourth pulse signal have the same timing. In yet another embodiment, please refer to Figure 3 , Figure 3 This is a circuit diagram of a relay detection circuit provided in an embodiment of the present invention, such as... Figure 3 As shown, the logic unit 233 includes AND gate U6D, AND gate U9D, and OR gate U10A; The two input terminals of AND gate U6D are respectively connected to the first comparison unit 231 and the second comparison unit 232, the output terminal of AND gate U6D is connected to the first input terminal of OR gate U10A, the two input terminals of AND gate U9D are respectively connected to the first comparison unit 231 and the second comparison unit 232, the output terminal of AND gate U9D is connected to the second input terminal of OR gate U10A, and the output terminal of OR gate U10A is connected to the controller 24. The AND gates U6D and U9D are used to output complementary fifth and sixth pulse signals to the OR gate U10A upon receiving the first comparison signal and the third comparison signal, so that the OR gate U10A outputs a closure detection signal; and Upon receiving the second comparison signal and the third comparison signal, both output a low-level signal to the OR gate U10A, so that the OR gate U10A outputs the disconnection detection signal.

[0037] Specifically, after the sampling module 22 outputs both the input voltage and the output voltage to the comparison control module 23, the second comparison unit 232 continuously outputs a third comparison signal based on the input voltage. When the first comparison unit 231 outputs a first comparison signal, since the first comparison signal is a high-level signal and the third comparison signal is a complementary third pulse signal and a fourth pulse signal, when AND gates U6D and U9D receive the high-level signal and the complementary third pulse signal and fourth pulse signal respectively, they will output complementary fifth pulse signal and sixth pulse signal. The fifth pulse signal has the same timing as the third pulse signal, and the sixth pulse signal has the same timing as the fourth pulse signal. When the two input terminals of OR gate U10A receive the fifth pulse signal and the sixth pulse signal respectively, since the fifth pulse signal and the sixth pulse signal are complementary, OR gate U10A will continuously output a high-level signal (closure detection signal), thereby enabling the controller 24 to determine that the relay 10 has been activated based on the closure detection signal.

[0038] If the first comparison unit 231 outputs a second comparison signal, then AND gates U9D and U6D will output low-level signals based on the received second and third comparison signals, thereby causing OR gate U10A to output a low-level signal (disconnection detection signal), so that controller 24 determines that relay 10 has not yet been activated. It should be noted that at the same time, the pulse signals received by the two input terminals of AND gate U6D and the two input terminals of AND gate U9D are complementary pulse signals. When both AND gates U6D and U9D receive complementary pulse signals, they will output a low-level signal to OR gate U10A based on the complementary pulse signals, thereby causing OR gate U10A to output a disconnection detection signal.

[0039] In yet another embodiment, such as Figure 3 As shown, the logic unit 233 also includes a resistor R251, a capacitor C96, a resistor R211, and a capacitor C34; The resistor R251 is connected to the output terminal of the AND gate U6D and the first input terminal of the OR gate U10A respectively. The resistor R251 is also grounded through the capacitor C96. The resistor R211 is connected to the output terminal of the AND gate U9D and the second input terminal of the OR gate U10A respectively. The resistor R211 is also grounded through the capacitor C34.

[0040] It can be seen that resistor R251 and capacitor C96 form the output filter circuit for AND gate U6D, and resistor R211 and capacitor C34 form the output filter circuit for AND gate U9D. These filter circuits filter noise from AND gates U6D and U9D, thereby reducing signal interference and improving the reliability of the closure detection signal output by OR gate U10A. It should be noted that since the relay input is connected to AC power, and AC power has a zero-point condition, at the AC zero-point moment, even if the relay is not closed, the voltage difference between the input and output voltages may be less than a preset threshold, resulting in a voltage spike. Therefore, the absorbed noise can be the voltage spike.

[0041] It should be noted that since the controller 24 determines the pull-in time of the relay 10 based on the time of the received closure detection signal and the time of the output drive signal, the controller 24 includes the signal delay caused by the filtering circuit in its calculation. That is, while the filtering circuit improves circuit reliability, it does not affect the calculation of the pull-in time. Alternatively, the values ​​of resistor R251 and capacitor C96 can be set very small, and the delay time generated by their filtering is negligible, thus not affecting the calculation of the pull-in time.

[0042] In another embodiment, a filtering circuit may not be necessary; the controller can automatically filter out voltage spikes and only calculate the relay engagement time when a closure detection signal is received.

[0043] In another embodiment, such as Figure 3 As shown, the first comparison unit 231 includes an operational amplifier U3B, a comparator U5B, a comparator U8B, a resistor R252, a resistor R255, a capacitor C84, and a capacitor C101; the second comparison unit 232 includes a comparator U4B and a comparator U7B. Both input terminals of the operational amplifier U3B are connected to the sampling module 22. The first input terminal of the operational amplifier U3B is also grounded through the resistor R252. The capacitor C84 is connected in parallel with the resistor R252. The second input terminal of the operational amplifier U3B is also connected to the output terminal of the operational amplifier U3B through the resistor R255. The capacitor C101 is connected in parallel with the resistor R255. The output terminal of the operational amplifier U3B is also connected to the first input terminal of the comparator U5B and the second input terminal of the comparator U8B, respectively. The second input terminal of the comparator U5B is connected to the ground terminal. The first input terminal of the comparator U8B is connected to the reference power supply. The output terminals of the comparators U5B and U8B are also connected to the logic unit 233.

[0044] The first input terminal of comparator U4B and the second input terminal of comparator U7B are both connected to the sampling module 22. The second input terminal of comparator U4B and the first input terminal of comparator U7B are both connected to the reference power supply. The output terminals of comparator U4B and comparator U7B are also connected to the logic unit 233.

[0045] Specifically, when the sampling module 22 acquires the input voltage (AD_V_IN) and the output voltage (AD_V_OUT), on the one hand, the first input terminal of the operational amplifier U3B receives the input voltage, and the second input terminal of the operational amplifier U3B receives the output voltage. At this time, the operational amplifier U3B determines the voltage difference between the input voltage and the output voltage, and amplifies the voltage difference between the input voltage and the output voltage and outputs it (AD_V_RLY) to the first input terminal of the comparator U5B and the second input terminal of the comparator U8B. At this time, if the difference between the input voltage and the output voltage is greater than or equal to the preset threshold, the comparator U5B will output a first pulse signal, and the comparator U8B will output a second pulse signal; if the difference between the input voltage and the output voltage is less than the preset threshold, both the comparator U5B and the comparator U8B will output a high-level signal. On the other hand, both the second input terminal of comparator U7B and the first input terminal of comparator U4B receive the input voltage collected by the sampling module 22. When comparator U7B receives the input voltage, it compares the input voltage with the reference voltage corresponding to the reference power supply and outputs a fourth pulse signal based on the comparison result. After receiving the input voltage, comparator U4B also compares the input voltage with the reference voltage and outputs a third pulse signal.

[0046] It should be noted that when comparator U5B outputs a first pulse signal and comparator U7B outputs a fourth pulse signal to the two input terminals of U6D, since the first pulse signal is complementary to the second pulse signal, and the third pulse signal is complementary to the fourth pulse signal, and the first pulse signal and the third pulse signal have the same timing, and the second pulse signal and the fourth pulse signal have the same timing, the first pulse signal and the fourth pulse signal are complementary, and the second pulse signal and the third pulse signal are complementary. Therefore, AND gate U6D will output a low-level signal based on the first pulse signal and the fourth pulse signal. At the same time, the two input terminals of U9D will also receive the second pulse signal output by comparator U8B and the third pulse signal output by comparator U4B, and output a low-level signal based on the second pulse signal and the third pulse signal. Based on this, OR gate U10A will output a disconnection detection signal.

[0047] If both comparators U5B and U8B output high-level signals, the second input terminals of AND gates U6D and U9D will both receive these high-level signals. In this case, the output signals of AND gates U6D and U9D are determined by the signals output by comparators U7B and U4B. That is, when the first input terminal of AND gate U6D receives the fourth pulse signal, it will output a sixth pulse signal with the same timing as the fourth pulse signal. Similarly, AND gate U9D will also output a fifth pulse signal with the same timing as the third pulse signal to OR gate U10A. When OR gate U10A receives the complementary fifth and sixth pulse signals, it can output a closure detection signal to controller 24 based on the fifth and sixth pulse signals.

[0048] In some embodiments, the first comparison unit 231 further includes a bias subunit (not shown), such as Figure 3 As shown, the bias sub-unit is a bidirectional diode D33; The first terminal of the bidirectional diode D33 is connected to the ground terminal, the second terminal of the bidirectional diode D33 is connected to the reference power supply, and the third terminal of the bidirectional diode D33 is connected to the output terminal of the operational amplifier U3B.

[0049] Specifically, the bidirectional diode D33 is used to clamp the voltage difference amplified by the operational amplifier U3B to output a stable second comparison signal to the logic unit 233.

[0050] In yet another embodiment, such as Figure 2 As shown, the sampling module 22 includes a first differential sampling unit 221 and a second differential sampling unit 222; The first differential sampling unit 221 is connected to the input terminal of the relay 10, and the second differential sampling unit 222 is connected to the output terminal of the relay 10. The first differential sampling unit 221 and the second differential sampling unit 222 are also connected to the comparison control module 23. The first differential sampling unit 221 is used to collect the input voltage at the input terminal of the relay 10, amplify the input voltage, and output the amplified input voltage to the comparison control module 23; The second differential sampling unit 222 is used to collect the output voltage of the output terminal of the relay 10, amplify the output voltage, and output the amplified output voltage to the comparison control module 23.

[0051] Specifically, when the energy storage power supply 200 starts working, the first differential sampling unit 221 will collect the input voltage of the input terminal of the relay 10 in real time, amplify the input voltage, and finally output the amplified input voltage to the comparison control module 23; at the same time, the second differential sampling unit 222 will also collect the output voltage of the output terminal of the relay 10 in real time, amplify the output voltage, and output it to the comparison control module 23, so that the comparison control module 23 can determine the actual closing time of the relay 10 based on the input voltage and the output voltage.

[0052] In some embodiments, combined with Figure 3 and Figure 4 The first differential sampling unit 221 includes a differential amplifier U1B, resistors R215, R247, R221, R224, R236, R239, capacitors C39, C41, and C57. The first input terminal of the differential amplifier U1B is connected to the fifth pin of the relay 10 (RLY4) through resistors R224 and R221. The second input terminal of the differential amplifier U1B is connected to the sixth pin of the relay 10 through resistors R239 and R236. The first input terminal of the differential amplifier U1B is also connected to the reference power supply through resistor R215. Resistor R215 is also grounded through capacitor C39. Capacitor C41 is connected in parallel with resistor R215. The second input terminal of the differential amplifier U1B is also connected to the output terminal of the differential amplifier U1B through resistor R247. Capacitor C57 is connected in parallel with resistor R247. The output terminal of the differential amplifier U1B is also connected to the comparison control module.

[0053] As we know, a differential amplifier is a device that amplifies the difference between two input signals. Therefore, when current flows through the input terminal of the relay 10, the differential amplifier U1B acquires the input voltage of the relay 10 input terminal, amplifies the input voltage, and finally outputs the amplified input voltage to the comparison control module 23.

[0054] It should be noted that resistors R221, R224, R236, and R239 are current-limiting resistors. By limiting the current flowing into the differential amplifier U1B through resistors R221, R224, R236, and R239, the differential amplifier U1B is provided with current-limiting protection.

[0055] In yet another embodiment, such as Figure 4 As shown, the second differential sampling unit 222 includes a differential amplifier U2B, resistors R218, R250, R226, R227, R240, R241, capacitors C40, C42, and C59. The first input terminal of the differential amplifier U2B is connected to the third pin of the relay 10 (RLY4) through resistors R227 and R226. The second input terminal of the differential amplifier U2B is connected to the fourth pin of the relay 10 through resistors R241 and R240. The first input terminal of the differential amplifier U2B is also connected to the reference power supply through resistor R218. Resistor R218 is also grounded through capacitor C40. Capacitor C42 is connected in parallel with resistor R218. The second input terminal of the differential amplifier U2B is also connected to the output terminal of the differential amplifier U2B through resistor R250. Capacitor C59 is connected in parallel with resistor R250. The output terminal of the differential amplifier U2B is also connected to the comparison control module 23.

[0056] It should be noted that the structure and working principle of the second differential sampling unit 222 are the same as those of the first differential sampling unit 221, and will not be described again here.

[0057] In some embodiments, such as Figure 4 As shown, the drive module 21 includes a switch Q30, a resistor R207, a resistor R208, a diode D34, a diode DS7, a resistor R204, and a capacitor EC3; The switching transistor Q30 is connected to the controller 24 through the resistor R207. The control terminal of the switching transistor Q30 is also grounded through the resistor R208. The first terminal of the switching transistor Q30 is connected to the negative terminal of the coil of the relay 10. The first terminal of the switching transistor Q30 is also connected to the positive terminal of the coil of the relay 10 through the diode DS7. The second terminal of the switching transistor Q30 is grounded. The diode DS7 is also connected to the cathode of the diode D34. The diode DS7 is also grounded through the capacitor EC3. The anode of the diode D34 is also connected to the power supply VCC through the resistor R204.

[0058] When the controller 24 outputs the drive signal, the switch Q30 receives the drive signal based on the resistor R207 and turns on based on the received drive signal. When the switch Q30 turns on, the negative terminal of the coil of the relay 10 is pulled low by the switch Q30. At the same time, the voltage of the power supply VCC is output to the positive terminal of the coil of the relay 10 through the resistor R204 and the diode D34. At this time, the coil of the relay 10 starts to work due to receiving the voltage of the power supply VCC, thereby controlling the connection of pins three and five of the relay 10, and controlling the connection of pins six and four of the relay 10. This allows the power supply voltage of the power supply 100 to be transmitted to the load 300 through the relay 10 to supply power to the load 300.

[0059] This invention provides a relay detection circuit, comprising a driving module, a sampling module, a comparison control module, and a controller. The driving module is connected to the coil terminal of the relay. The sampling module is connected to both the input and output terminals of the relay. The comparison control module is connected to the sampling module, and both the comparison control module and the driving module are connected to the controller. The driving module receives a driving signal output from the controller and starts operating according to the driving signal to energize the coil terminal of the relay. The sampling module collects the input voltage at the input terminal and the output voltage at the output terminal of the relay. The comparison control module outputs a closure detection signal to the controller when the voltage difference between the input voltage and the output voltage is less than a preset threshold. This allows for accurate determination of the contact open / closed state using the voltage difference between the two terminals, improving the accuracy of relay operation state identification. The controller can accurately calculate the actual closing time of the relay by combining the timing of the driving signal issuance and the timing of the closure detection signal receipt, effectively calibrating the inherent delay caused by the driving signal transmission and mechanical action, ensuring that the relay can close accurately at the zero-crossing point, thereby avoiding the influence of inrush current on the relay and improving the safety and reliability of the circuit.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; under the concept of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present invention as described above, which are not provided in detail for the sake of brevity; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A relay detection circuit, characterized in that, The relay detection circuit includes a driving module, a sampling module, a comparison control module, and a controller; The driving module is connected to the coil terminal of the relay, the sampling module is connected to the input terminal and the output terminal of the relay respectively, the comparison control module is connected to the sampling module, and both the comparison control module and the driving module are connected to the controller. The drive module is used to receive the drive signal output by the controller and start working according to the drive signal to drive the coil terminal of the relay to be energized; The sampling module is used to collect the input voltage at the input terminal and the output voltage at the output terminal of the relay; The comparison control module is used to output a closure detection signal to the controller when the voltage difference between the input voltage and the output voltage is less than a preset threshold, so that the controller can determine the activation time of the relay based on the time of outputting the drive signal and the time of receiving the closure detection signal; The comparison control module includes a first comparison unit, a second comparison unit, and a logic unit. The first comparison unit is connected to the sampling module and the logic unit respectively, the second comparison unit is connected to the sampling module and the logic unit respectively, and the logic unit is also connected to the controller; The first comparison unit is configured to output a first comparison signal when the voltage difference between the input voltage and the output voltage is less than the preset threshold; and When the voltage difference between the input voltage and the output voltage is greater than or equal to the preset threshold, a second comparison signal is output; The second comparison unit is used to output a third comparison signal based on the input voltage; The logic unit is configured to output the closure detection signal upon receiving the first comparison signal and the third comparison signal; and Upon receiving the second comparison signal and the third comparison signal, a disconnection detection signal is output. The first comparison signal is a high-level signal. The second comparison signal includes complementary first pulse signals and second pulse signals. The third comparison signal includes complementary third pulse signals and fourth pulse signals. The first pulse signal and the third pulse signal have the same timing sequence. The second pulse signal and the fourth pulse signal have the same timing sequence.

2. The circuit according to claim 1, characterized in that, The comparison control module is further configured to output a first comparison signal when the voltage difference between the input voltage and the output voltage is less than the preset threshold, and to output the closure detection signal based on the input voltage and the first comparison signal.

3. The circuit according to claim 1, characterized in that, The logic unit includes AND gate U6D, AND gate U9D and OR gate U10A; The two input terminals of AND gate U6D are respectively connected to the first comparison unit and the second comparison unit, the output terminal of AND gate U6D is connected to the first input terminal of OR gate U10A, the two input terminals of AND gate U9D are respectively connected to the first comparison unit and the second comparison unit, the output terminal of AND gate U9D is connected to the second input terminal of OR gate U10A, and the output terminal of OR gate U10A is connected to the controller. The AND gates U6D and U9D are used to output complementary fifth and sixth pulse signals to the OR gate U10A upon receiving the first comparison signal and the third comparison signal, so that the OR gate U10A outputs a closure detection signal; and Upon receiving the second comparison signal and the third comparison signal, both output a low-level signal to the OR gate U10A, so that the OR gate U10A outputs the disconnection detection signal.

4. The circuit according to claim 3, characterized in that, The logic unit also includes resistor R251, capacitor C96, resistor R211, and capacitor C34; The resistor R251 is connected to the output terminal of the AND gate U6D and the first input terminal of the OR gate U10A respectively. The resistor R251 is also grounded through the capacitor C96. The resistor R211 is connected to the output terminal of the AND gate U9D and the second input terminal of the OR gate U10A respectively. The resistor R211 is also grounded through the capacitor C34.

5. The circuit according to claim 1, characterized in that, The first comparison unit includes an operational amplifier U3B, a comparator U5B, a comparator U8B, a resistor R252, a resistor R255, a capacitor C84, and a capacitor C101; Both input terminals of the operational amplifier U3B are connected to the sampling module. The first input terminal of the operational amplifier U3B is also grounded through the resistor R252. The capacitor C84 is connected in parallel with the resistor R252. The second input terminal of the operational amplifier U3B is also connected to the output terminal of the operational amplifier U3B through the resistor R255. The capacitor C101 is connected in parallel with the resistor R255. The output terminal of the operational amplifier U3B is also connected to the first input terminal of the comparator U5B and the second input terminal of the comparator U8B, respectively. The second input terminal of the comparator U5B is connected to the ground terminal. The first input terminal of the comparator U8B is connected to the reference power supply. The output terminals of the comparators U5B and U8B are also connected to the logic unit.

6. The circuit according to claim 5, characterized in that, The first comparison unit further includes a bias sub-unit, wherein the bias sub-unit is a bidirectional diode D33; The first terminal of the bidirectional diode D33 is connected to the ground terminal, the second terminal of the bidirectional diode D33 is connected to the reference power supply, and the third terminal of the bidirectional diode D33 is connected to the output terminal of the operational amplifier U3B.

7. The circuit according to claim 1, characterized in that, The second comparison unit includes comparator U4B and comparator U7B; The first input terminal of comparator U4B and the second input terminal of comparator U7B are both connected to the sampling module. The second input terminal of comparator U4B and the first input terminal of comparator U7B are both connected to the reference power supply. The output terminals of comparator U4B and comparator U7B are also connected to the logic unit.

8. The circuit according to any one of claims 1-7, characterized in that, The sampling module includes a first differential sampling unit and a second differential sampling unit; The first differential sampling unit is connected to the input terminal of the relay, and the second differential sampling unit is connected to the output terminal of the relay. Both the first differential sampling unit and the second differential sampling unit are also connected to the comparison control module. The first differential sampling unit is used to collect the input voltage at the input terminal of the relay, amplify the input voltage, and output the amplified input voltage to the comparison control module; The second differential sampling unit is used to acquire the output voltage of the relay's output terminal, amplify the output voltage, and output the amplified output voltage to the comparison control module.

9. An energy storage power source, characterized in that, The energy storage power source includes: Relays; and The relay detection circuit as described in any one of claims 1-8.

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