On-line detection circuit and system based on double sampling

Abstract

The invention relates to the technical field of electronic circuits, and discloses an in-place detection circuit and system based on double sampling, which can accurately judge whether an external CT is in place or not without electrifying a power line of the external CT and starting up on the basis of double sampling: in a standby state, a processing chip instantaneously closes a switch execution module through a switch driving module, so that the external CT is in place; the first voltage sampling module and the second voltage sampling module respectively collect loop voltage and CT end voltage in sequence; by means of software judgment logic, if the first sampling voltage is a first preset value, it is judged that the CT is in place, and if the first sampling voltage is a second preset value and the second sampling voltage is a third preset value, it is judged that the CT is not in place. The misoperation risk caused by overcurrent misjudgment in a traditional scheme is thoroughly eliminated, and the safety coefficient is greatly improved; and meanwhile, online remote detection is supported, operation and maintenance personnel can master the CT connection state at any time, the on-site inspection cost is remarkably reduced, and unprecedented convenient and reliable guarantee is provided for daily operation and maintenance of the household energy storage inverter.

Description

Technical Field

[0001] This invention relates to the field of electronic circuit technology, and in particular to an in-situ detection circuit and system based on dual sampling. Background Technology

[0002] In recent years, the residential energy storage market has experienced rapid and exceptionally strong growth, a trend that has powerfully driven the entire energy storage inverter technology field into a phase of rapid iteration and upgrading. With continuous technological advancements, competition in the energy storage inverter market has become increasingly fierce. To gain a foothold in the market, companies are adopting various strategies, with extreme cost reduction becoming a common choice for many. This has placed enormous pressure on the entire industry in terms of cost control.

[0003] In terms of current applications of residential energy storage inverters, to fully meet the diverse and unique needs of user scenarios, most residential energy storage inverters, except for some special applications, adopt an external CT sampling solution. This solution has significant advantages: its installation process is simple and quick, effectively improving construction efficiency and reducing installation costs, and therefore it has been widely used in the market.

[0004] However, external CT sampling solutions also have some issues that cannot be ignored in practical applications. Since external CT sampling is typically achieved through RJ45 terminals and wire locking, this connection method is prone to loose or missed connections due to environmental factors and human error during long-term use. Once this occurs, it will seriously affect the normal operation of the energy storage inverter and may even lead to equipment damage, causing unnecessary losses to the user. Therefore, to ensure the stable and reliable operation of the energy storage inverter, it is particularly necessary to detect whether the external CT is in place.

[0005] Traditional detection methods typically require external current transformers (CTs) to sample the power line overcurrent to determine if the CT is in place. However, this method has significant drawbacks. In actual operation, the power line overcurrent can be affected by various factors, leading to misjudgments and a risk of system malfunction. A malfunction could not only affect the normal operation of the energy storage inverter but also threaten the stability and safety of the entire energy storage system.

[0006] Given the above circumstances, in order to effectively solve the problems existing in the current technology, improve the operational stability and reliability of residential energy storage inverters, and reduce the risk of system malfunctions, it is imperative to improve the existing technology, which has become an urgent need for the current development of the industry.

[0007] The above information is provided as background information only to aid in understanding this disclosure and does not constitute an assertion or admission that any of the above content can be used as prior art relative to this disclosure. Summary of the Invention

[0008] This invention provides an in-situ detection circuit and system based on dual sampling to solve the problems existing in the prior art.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] In a first aspect, the present invention provides an in-situ detection circuit based on dual sampling, comprising a switch driving module, a switch execution module, a first voltage sampling module, and a second voltage sampling module; wherein,

[0011] The switch driving module is connected to the processing chip and is used to receive control signals from the processing chip to generate driving current;

[0012] The switch execution module is connected to the switch driving module, the first voltage sampling module, and the second voltage sampling module respectively, and is used to perform the action of closing the switch after receiving the driving current, so as to turn on the first voltage sampling module and the second voltage sampling module.

[0013] The first voltage sampling module is connected to the processing chip and is used to sample the voltage of the circuit where the switch execution module is located after the circuit is turned on, and to feed back the first sampled voltage to the processing chip.

[0014] The second voltage sampling module is connected to the current transformer CT and the processing chip respectively, and is used to sample the voltage of the current transformer CT after it is turned on, and feed the second sampled voltage back to the processing chip.

[0015] If the first sampled voltage is a first preset value, then the current transformer CT is determined to be in place; if the first sampled voltage is a second preset value and the second sampled voltage is a third preset value, then the current transformer CT is determined to be out of place.

[0016] Furthermore, in the dual-sampling-based in-situ detection circuit, the switch driving module includes a Test_control 1 port, a Test_control 2 port, a first Zener diode ZD1, a second Zener diode ZD2, a first transistor Q1, a second transistor Q2, a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4;

[0017] The Test_control 1 port and the Test_control 2 port are respectively connected to the processing chip;

[0018] The cathode of the first Zener diode ZD1 is connected to the Test_control 1 port, and the anode of the first Zener diode ZD1 is connected to the base of the first transistor Q1.

[0019] The emitter of the first transistor Q1 is grounded;

[0020] The positive terminal of the first diode D1 and the second diode D2 are connected in parallel and connected to the collector of the first transistor Q1, and the negative terminal is connected to the first auxiliary power supply.

[0021] The negative terminal of the second Zener diode ZD2 is connected to the Test_control 2 port, and the positive terminal of the second Zener diode ZD2 is connected to the base of the second transistor Q2;

[0022] The emitter of the second transistor Q2 is grounded;

[0023] The positive terminal of the third diode D3 and the fourth diode D4 are connected in parallel and connected to the collector of the second transistor Q2, while the negative terminal is connected to the first auxiliary power supply.

[0024] Furthermore, in the dual-sampling-based in-situ detection circuit, the switch driving module further includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4.

[0025] The first resistor R1 and the first capacitor C1 are connected in parallel. One end of the first resistor R1 is connected to the base of the first transistor Q1, and the other end is connected to the emitter of the first transistor Q1.

[0026] The second resistor R2 is connected in series between the positive terminal of the first Zener diode ZD1 and the base of the first transistor Q1;

[0027] One end of the second capacitor C2 is connected to the first auxiliary power supply, and the other end is grounded;

[0028] The third resistor R3 and the third capacitor C3 are connected in parallel. One end of the connection is connected to the base of the second transistor Q2, and the other end is connected to the emitter of the second transistor Q2.

[0029] The fourth resistor R4 is connected in series between the positive terminal of the second Zener diode ZD2 and the base of the second transistor Q2;

[0030] One end of the fourth capacitor C4 is connected to the first auxiliary power supply, and the other end is grounded.

[0031] Furthermore, in the dual-sampling-based in-situ detection circuit, the switch execution module includes a first relay RLY1, a second relay RLY2, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and a fifth diode D5;

[0032] The coil of the first relay RLY1 is connected in parallel to the first diode D1 and the second diode D2. The moving contact of the first relay RLY1 is connected to the second auxiliary power supply after being connected in series with the seventh resistor R7 and the fifth resistor R5. The stationary contact of the first relay RLY1 is connected to the first end of the secondary side of the current transformer CT.

[0033] The coil of the second relay RLY2 is connected in parallel to the third diode D3 and the fourth diode D4. The moving contact of the second relay RLY2 is connected to the positive terminal of the fifth diode D5. The stationary contact of the first relay RLY1 is connected to the second terminal of the secondary side of the current transformer CT.

[0034] The negative terminal of the fifth diode D5 is connected to the first terminal of the secondary side of the current transformer CT.

[0035] The sixth resistor R6 is connected in parallel across the two ends of the secondary side of the current transformer CT;

[0036] The second terminal of the secondary side of the current transformer (CT) is grounded.

[0037] Furthermore, in the dual-sampling-based in-situ detection circuit, the first voltage sampling module includes a CT_TEST_AD+ port and a CT_AD- port;

[0038] The CT_TEST_AD+ port is connected to the first end of the seventh resistor R7 and the processing chip, respectively.

[0039] The CT_AD-port is connected to the second terminal of the seventh resistor R7 and the processing chip.

[0040] Furthermore, in the dual-sampling-based in-situ detection circuit, the second voltage sampling module includes a CT_AD+ port and a CT_AD- port;

[0041] The CT_AD+ port is connected to the first end of the secondary side of the current transformer CT and the processing chip, respectively.

[0042] The CT_AD-port is connected to the second terminal of the secondary side of the current transformer CT and the processing chip.

[0043] Furthermore, in the dual-sampling-based in-situ detection circuit, the first auxiliary power supply provides a voltage of +12V;

[0044] The second auxiliary power supply provides a voltage of +3.3V.

[0045] Furthermore, in the dual-sampling-based in-situ detection circuit, the first Zener diode ZD1 and the second Zener diode ZD2 are 3.3V Zener diodes.

[0046] In a second aspect, the present invention provides an in-situ detection system based on dual sampling, including a processing chip, a current transformer (CT), and an in-situ detection circuit based on dual sampling as provided in the first aspect above.

[0047] The processing chip is used to send control signals to the switch driving module so that the switch driving module generates a drive current;

[0048] The switch execution module is used to perform the action of closing the switch after receiving the drive current, so as to turn on the first voltage sampling module and the second voltage sampling module;

[0049] The first voltage sampling module is used to sample the voltage of the circuit where the switch execution module is located, and feed the first sampled voltage back to the processing chip;

[0050] The second voltage sampling module is used to sample the voltage of the current transformer (CT) and feed the second sampled voltage back to the processing chip;

[0051] The processing chip is also used to make the following judgments:

[0052] If the first sampled voltage is a first preset value, then the current transformer CT is determined to be in place; if the first sampled voltage is a second preset value and the second sampled voltage is a third preset value, then the current transformer CT is determined to be out of place.

[0053] Furthermore, in the dual-sampling-based in-situ detection system, the processing chip is also used to perform the following judgments:

[0054] Before starting in-situ testing, first confirm the current sampling value of the current transformer CT and ensure that there is no current on the power line of the current transformer CT before starting in-situ testing.

[0055] The first sampling voltage is checked to see if it is 0V; if it is not 0V, the circuit has a fault and the detection is terminated; if the first sampling voltage is 0V, the next step is to send a control signal to the switch driver module so that the switch driver module generates a drive current.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] This invention provides an in-situ detection circuit and system based on dual sampling. By using dual sampling, it achieves accurate determination of the presence of an external current transformer (CT) without requiring the power line to be energized or the system to be powered on. In standby mode, the processing chip, via a switch drive module, instantaneously closes the switch execution module, and the first and second voltage sampling modules sequentially collect the circuit voltage and the CT terminal voltage. Based on software judgment logic, if the first sampled voltage is equal to a first preset value, the CT is determined to be in place; if the first sampled voltage is equal to a second preset value and the second sampled voltage is equal to a third preset value, the CT is determined to be out of place. The entire process requires no power line overcurrent and no system startup, completely eliminating the risk of malfunction caused by overcurrent misjudgment in traditional solutions, significantly improving safety. Simultaneously, it supports online remote detection, allowing maintenance personnel to monitor the CT connection status at any time, significantly reducing on-site inspection costs and providing unprecedented convenience and reliability for the daily operation and maintenance of residential energy storage inverters.

[0058] The present invention has other features and advantages, which will be apparent from or will be set forth in detail in the accompanying drawings and the following detailed description, which together serve to explain the particular principles of the invention. Attached Figure Description

[0059] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0060] Figure 1 This is a functional module diagram of an in-situ detection circuit based on dual sampling provided in Embodiment 1 of the present invention;

[0061] Figure 2 This is a schematic diagram of the in-situ detection circuit based on dual sampling provided in Embodiment 1 of the present invention.

[0062] Figure label:

[0063] Switch drive module 1, switch execution module 2, first voltage sampling module 3, second voltage sampling module 4, processing chip 5, current transformer CT 6. Detailed Implementation

[0064] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0065] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0066] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0067] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0068] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0069] Unless otherwise specified, the use of terms such as “comprising,” “including,” “having,” or other similar expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0070] In this application, expressions such as "greater than", "less than", and "exceeding" are understood to exclude the stated number; expressions such as "above", "below", and "within" are understood to include the stated number. Furthermore, in the description of the embodiments of this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times", unless otherwise explicitly specified.

[0071] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0072] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. For those skilled in the art to which this application pertains, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0073] Example 1

[0074] Please refer to Figure 1 This invention provides an in-situ detection circuit based on dual sampling, which mainly consists of a switch driving module 1, a switch execution module 2, a first voltage sampling module 3, and a second voltage sampling module 4.

[0075] The switch drive module 1 is connected to the processing chip 5, and its main function is to receive control signals from the processing chip 5. After receiving the control signal, the switch drive module 1 can generate a corresponding drive current to provide power support for the subsequent operation of the switch execution module 2.

[0076] The switch execution module 2 is connected to both the switch driving module 1 and the voltage sampling modules (including the first voltage sampling module 3 and the second voltage sampling module 4). When the switch execution module 2 receives the drive current generated by the switch driving module 1, it performs the action of closing the switch. This action enables the first voltage sampling module 3 and the second voltage sampling module 4 to conduct, allowing these two modules to sample the corresponding voltages.

[0077] The first voltage sampling module 3 is connected to the processing chip 5. After the switch execution module 2 is turned on, the first voltage sampling module 3 will accurately sample the voltage of the circuit where the switch execution module 2 is located. After sampling, the module will feed back the collected first sampled voltage to the processing chip 5 so that the processing chip 5 can perform subsequent judgment and processing based on the voltage value.

[0078] The second voltage sampling module 4 is connected to both the current transformer CT 6 and the processing chip 5. Similarly, after the switch execution module 2 is turned on, the second voltage sampling module 4 samples the voltage of the current transformer CT 6. After sampling, the module feeds back the acquired second sampled voltage to the processing chip 5, providing crucial data for the processing chip 5 to determine the presence status of the current transformer CT 6.

[0079] In terms of the judgment logic, if the value of the first sampled voltage is the first preset value, it can be determined that the current transformer CT6 is in the position; if the value of the first sampled voltage is the second preset value and the value of the second sampled voltage is the third preset value, it can be determined that the current transformer CT6 is not in the position.

[0080] The dual-sampling-based presence detection circuit proposed in this invention, through a unique dual-sampling technology, enables accurate determination of the presence of an external current transformer (CT) even when the power line is energized without requiring an external CT and the device is not powered on. Specifically, when the device is in standby mode, the processing chip 5 sends a control signal to the switch drive module 1, which generates a drive current to momentarily close the switch execution module 2. Subsequently, the first voltage sampling module 3 and the second voltage sampling module 4 sequentially acquire the loop voltage and the CT terminal voltage. The processing chip 5 analyzes and judges the acquired voltage values ​​according to preset software judgment logic. If the first sampled voltage is a first preset value, the CT is determined to be present; if the first sampled voltage is a second preset value and the second sampled voltage is a third preset value, the CT is determined to be absent.

[0081] Throughout the entire testing process, no overcurrent occurs in the power lines, and the system does not need to be started. This feature completely eliminates the risk of malfunction caused by overcurrent misjudgment in traditional solutions, greatly improving the safety factor of the equipment. Simultaneously, the circuit also supports online remote testing, allowing maintenance personnel to monitor the connection status of the current transformers (CTs) at any time without being physically present on-site. This advantage significantly reduces the cost of on-site inspections, providing unprecedented convenience and reliability for the daily operation and maintenance of residential energy storage inverters, and powerfully promoting the improvement of the operation and maintenance management level of residential energy storage inverters.

[0082] Please refer to Figure 2 In one embodiment of this example, the switch driving module 1 includes a Test_control 1 port, a Test_control 2 port, a first Zener diode ZD1, a second Zener diode ZD2, a first transistor Q1, a second transistor Q2, a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4.

[0083] Test_control1 and Test_control2 ports: These two ports are connected to the processing chip 5. Through this connection, the processing chip 5 can send control signals to the switch driver module 1, thereby controlling the working state of the switch driver module 1 and providing instruction input for the orderly operation of the entire circuit system.

[0084] The first Zener diode ZD1 has its negative terminal connected to the Test_control1 port, and its positive terminal connected to the base of the first transistor Q1. The first Zener diode ZD1 plays a role in stabilizing the voltage in the circuit, ensuring that the voltage input to the base of the first transistor Q1 remains within a suitable range. This prevents voltage fluctuations from affecting the normal operation of the first transistor Q1 and ensures the stability of the circuit.

[0085] The first transistor Q1 has its emitter grounded, providing a stable reference potential. The first diode D1 and the second diode D2 are connected in parallel, with their positive terminals connected to the collector of the first transistor Q1 and their negative terminals connected to the first auxiliary power supply. The parallel connection of the first diode D1 and the second diode D2 provides protection in the circuit, such as preventing overvoltage damage to subsequent circuit components, and also improves the electrical performance of the circuit to some extent. When the first transistor Q1 receives a suitable signal from the first Zener diode ZD1, it will turn on or off according to the signal, thereby controlling the on / off state of the subsequent circuit.

[0086] The second Zener diode ZD2 has its negative terminal connected to the Test_control2 port and its positive terminal connected to the base of the second transistor Q2. Similar to the first Zener diode ZD1, the second Zener diode ZD2 is used to stabilize the voltage input to the base of the second transistor Q2, ensuring that the second transistor Q2 operates under a stable voltage environment and preventing circuit failure due to abnormal voltage.

[0087] The second transistor Q2's emitter is also grounded, providing a stable reference potential. The third diode D3 and the fourth diode D4 are connected in parallel, with their positive terminals connected to the collector of the second transistor Q2 and their negative terminals connected to the first auxiliary power supply. The parallel-connected third diode D3 and fourth diode D4 have similar functions to the first diode D1 and the second diode D2, providing protection and improving electrical performance in the circuit. The second transistor Q2 controls its on / off state based on the signal received from the second Zener diode ZD2, thus working in conjunction with the first transistor Q1 to control the output signal of the switch drive module 1.

[0088] In summary, through the precise connection and coordinated operation of the above-mentioned components, the switch drive module 1 can generate a stable and appropriate drive current according to the control signal sent by the processing chip 5, providing a strong guarantee for the normal operation of the subsequent switch execution module 2, thereby ensuring that the entire dual-sampling-based in-situ detection circuit can operate stably and reliably.

[0089] Please refer to this again. Figure 2 In one embodiment of this example, the switch driving module 1 further includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4.

[0090] The first resistor R1 and the first capacitor C1 are connected in parallel. One end of the parallel connection is connected to the base of the first transistor Q1, and the other end is connected to the emitter of the first transistor Q1. In this connection method, the first resistor R1 mainly serves to limit the current, restricting the current flowing into the base of the first transistor Q1 to prevent damage to the first transistor Q1 due to excessive current, ensuring that the first transistor Q1 operates within a safe current range. The first capacitor C1 has filtering and coupling functions. It can filter out high-frequency noise interference in the base circuit, making the signal input to the base of the first transistor Q1 purer and more stable. At the same time, during signal transmission, the first capacitor C1 also acts as a coupler, ensuring that the signal can be smoothly transmitted from the input terminal to the base of the first transistor Q1 without affecting the signal transmission quality.

[0091] The second resistor R2 is connected in series between the anode of the first Zener diode ZD1 and the base of the first transistor Q1. The function of the second resistor R2 is to divide the voltage output by the first Zener diode ZD1. By adjusting the value of the second resistor R2, the voltage value obtained at the base of the first transistor Q1 can be precisely controlled, thereby ensuring that the first transistor Q1 can operate under a suitable bias voltage, achieving stable conduction and cutoff control, and improving the reliability and stability of the circuit.

[0092] The second capacitor C2: One end of the second capacitor C2 is connected to the first auxiliary power supply, and the other end is grounded. The second capacitor C2 mainly functions as a power supply filter in the circuit. It can filter out high-frequency noise and ripple in the first auxiliary power supply, making the output voltage of the first auxiliary power supply smoother and more stable. This is crucial for ensuring the normal operation of all components in the entire switch drive module 1, because a stable power supply voltage can avoid problems such as component performance degradation or malfunction caused by voltage fluctuations, thus improving the overall performance and reliability of the circuit.

[0093] The third resistor R3 and the third capacitor C3 are connected in parallel. One end of the parallel connection is connected to the base of the second transistor Q2, and the other end is connected to the emitter of the second transistor Q2. Similar to the function of the first resistor R1 and the first capacitor C1, the third resistor R3 limits the current flowing into the base of the second transistor Q2, protecting it from damage caused by excessive current. The third capacitor C3 has filtering and coupling functions, filtering out high-frequency noise in the base circuit of the second transistor Q2, ensuring the purity of the input signal, and achieving smooth signal coupling and transmission, ensuring that the second transistor Q2 can accurately control its conduction and cutoff states according to the input signal.

[0094] The fourth resistor, R4, is connected in series between the anode of the second Zener diode ZD2 and the base of the second transistor Q2. R4 also acts as a voltage divider. By appropriately selecting the value of R4, the voltage at the base of the second transistor Q2 can be precisely adjusted, allowing Q2 to operate under suitable bias conditions, achieving stable switching control, and improving the stability and reliability of the circuit.

[0095] Fourth capacitor C4: One end of the fourth capacitor C4 is connected to the first auxiliary power supply, and the other end is grounded. The fourth capacitor C4 is also used to filter the first auxiliary power supply, further removing high-frequency interference components in the power supply, ensuring that the first auxiliary power supply provides cleaner and more stable power to the entire switch drive module 1, and ensuring that all components in the circuit can operate normally and reliably.

[0096] In summary, the resistors and capacitors in the switch drive module 1 cooperate with each other through their specific connection methods, playing an important role in the stable operation of the circuit, the accurate transmission of signals, and the effective protection of components, thereby ensuring that the entire dual-sampling-based in-situ detection circuit can work efficiently and reliably.

[0097] Please refer to this again. Figure 2 In one embodiment of this example, the switch execution module 2 includes a first relay RLY1, a second relay RLY2, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and a fifth diode D5;

[0098] The coil of the first relay RLY1 is connected in parallel with the first diode D1 and the second diode D2. This connection method forms a parallel circuit between the coil of the first relay RLY1, the first diode D1, and the second diode D2, sharing the same auxiliary power supply. When the switch drive module 1 outputs a suitable drive signal, the branch containing the first diode D1 and the second diode D2 is turned on, providing operating current to the coil of the first relay RLY1, causing the first relay RLY1 to operate.

[0099] The moving contact of the first relay RLY1 is connected to the second auxiliary power supply via a series connection of the seventh resistor R7 and the fifth resistor R5. The seventh resistor R7 and the fifth resistor R5 serve to limit current and divide voltage, restricting the current flowing into subsequent circuits to prevent damage to circuit components due to excessive current. Simultaneously, by appropriately selecting the resistor values, voltage can be distributed to meet the voltage requirements of different parts of the circuit.

[0100] The stationary contact of the first relay RLY1 is connected to the first terminal of the secondary side of the current transformer CT 6. When the first relay RLY1 is energized and engaged, the moving contact closes with the stationary contact, thereby introducing the voltage signal of the second auxiliary power supply after being divided and current-limited by the seventh resistor R7 and the fifth resistor R5 to the first terminal of the secondary side of the current transformer CT 6, providing the necessary conditions for the normal operation of the current transformer CT 6.

[0101] The coil of the second relay RLY2 is connected in parallel with the third diode D3 and the fourth diode D4. Similar to the coil connection of the first relay RLY1, when the switch drive module 1 outputs the corresponding control signal, the branch containing the third diode D3 and the fourth diode D4 is turned on, supplying power to the coil of the second relay RLY2, causing the second relay RLY2 to operate.

[0102] The moving contact of the second relay RLY2 is connected to the positive terminal of the fifth diode D5. The fifth diode D5 serves a protective and signal guiding function in the circuit. It prevents reverse current from flowing through the circuit, avoiding damage to other components; simultaneously, it guides the current to flow in a specific direction, ensuring the correct transmission of circuit signals.

[0103] The stationary contact of the second relay RLY2 is connected to the second terminal of the secondary side of the current transformer CT 6. When the second relay RLY2 is energized and engaged, the moving contact closes with the stationary contact, cooperating with the action of the first relay RLY1 to complete the connection and control of the secondary side circuit of the current transformer CT 6, thereby realizing a specific circuit function.

[0104] The negative terminal of the fifth diode D5 is connected to the first terminal of the secondary side of the current transformer CT 6, and the positive terminal is connected to the moving contact of the second relay RLY2. As mentioned earlier, the fifth diode D5 mainly serves to protect the circuit and regulate the current flow. During circuit operation, it can prevent component damage that may be caused by reverse current, ensuring the stable operation of the secondary side circuit of the current transformer CT 6.

[0105] The sixth resistor, R6, is connected in parallel across the secondary side of the current transformer CT6. Here, the sixth resistor R6 serves as short-circuit protection and current stabilization. When an abnormal situation occurs on the secondary side of the current transformer CT6, such as an open circuit generating high voltage, the sixth resistor R6 provides a low-impedance path to shunt the current, preventing damage to other components in the circuit. Simultaneously, under normal operating conditions, the sixth resistor R6 also plays a role in stabilizing the current on the secondary side of the current transformer CT6, ensuring stable circuit performance.

[0106] The second terminal of the secondary side of current transformer CT 6 is grounded. Grounding is a very important safety measure in the circuit. It can stabilize the potential of the secondary side of current transformer CT 6 at zero potential, providing a stable reference potential for the entire circuit. At the same time, in the event of a circuit fault or an abnormal situation such as a lightning strike, grounding can quickly conduct the current to the earth, preventing electric shock to personnel and damage to equipment, and ensuring the safe operation of the circuit.

[0107] In summary, the switch execution module 2, through precise connection and coordinated operation between its components, can accurately control the on / off state and signal transmission of the secondary circuit of the current transformer CT 6 according to the control signal from the switch drive module 1, while utilizing various protection components to ensure the safe and stable operation of the circuit under various working conditions.

[0108] Please refer to this again. Figure 2In one embodiment of this invention, the first voltage sampling module 3 and the second voltage sampling module 4 are responsible for accurately sampling the voltage at different locations in the circuit and transmitting the sampled signals to the processing chip 5. They work closely with other components in the circuit to ensure the stable operation and accurate detection of the entire dual-sampling-based in-situ detection circuit.

[0109] Specifically, the first voltage sampling module 3 includes a CT_TEST_AD+ port and a CT_AD- port; these two ports are the key interfaces for the module to interact with external circuits, through which the sampled voltage signal can be accurately transmitted.

[0110] Connection of the CT_TEST_AD+ port: The CT_TEST_AD+ port is connected to the first terminal of the seventh resistor R7 and the processing chip 5. The seventh resistor R7 functions as a current limiter and voltage divider in the circuit. When the moving contact of the first relay RLY1 closes, the second auxiliary power supply, after being divided by the seventh resistor R7 and the fifth resistor R5, receives a voltage signal at the first terminal of the seventh resistor R7, which is then transmitted to the processing chip 5 through the CT_TEST_AD+ port. The processing chip 5 can acquire and analyze this voltage signal to obtain information related to the operating state of the first relay RLY1 and the voltages of related circuits, providing a basis for subsequent circuit control and state judgment.

[0111] Connection of the CT_AD- port: The CT_AD- port is connected to the second terminal of the seventh resistor R7 and the processing chip 5. There is a potential difference between the voltage signal at the second terminal of the seventh resistor R7 and the first terminal. This voltage signal is transmitted to the processing chip 5 through the CT_AD- port, forming a voltage sampling pair with the signal transmitted through the CT_TEST_AD+ port. The processing chip 5 can more accurately determine the voltage changes in the circuit based on the voltage difference between these two ports, improving the accuracy and reliability of the sampling.

[0112] Please refer to this again. Figure 2 In one embodiment of this invention, the second voltage sampling module 4 includes a CT_AD+ port and a CT_AD- port; these also serve as interfaces for connecting the module to external circuits and for transmitting the sampled voltage signals.

[0113] Connection of the CT_AD+ port: The CT_AD+ port is connected to the first terminal of the secondary side of the current transformer CT 6 and the processing chip 5, respectively. The current transformer CT 6 is used to detect the current in the circuit and convert it into a voltage signal on the secondary side. The CT_AD+ port acquires the voltage signal from the first terminal of the secondary side of the current transformer CT 6 and transmits it to the processing chip 5, enabling the processing chip 5 to obtain the voltage information corresponding to the current detected by the current transformer CT 6 in real time, and then analyze and judge the current state in the circuit.

[0114] Connection of the CT_AD- port: The CT_AD- port is connected to the second terminal of the secondary side of current transformer CT 6 and processing chip 5. There is a potential difference between the voltage signal at the second terminal of the secondary side of current transformer CT 6 and the first terminal. This voltage signal is transmitted to processing chip 5 through the CT_AD- port, forming a voltage sampling pair with the signal transmitted through the CT_AD+ port. Based on the voltage difference between these two ports, processing chip 5 can accurately calculate the voltage value on the secondary side of current transformer CT 6, thereby accurately reflecting the magnitude and changes of the current in the circuit, providing crucial data support for functions such as in-situ detection.

[0115] In one embodiment of this invention, the first auxiliary power supply provides a voltage of +12V;

[0116] The second auxiliary power supply provides a voltage of +3.3V.

[0117] The first Zener diode ZD1 and the second Zener diode ZD2 are 3.3V Zener diodes.

[0118] This invention focuses on the detection of the presence status of the current transformer CT 6 by the processing chip 5. Through the coordinated operation of the switch driving module 1, the switch execution module 2, the first voltage sampling module 3, and the second voltage sampling module 4, combined with specific control signal logic, the accurate determination of the presence status of the current transformer CT 6 is achieved. The implementation steps will be described in detail below.

[0119] I. Control signal triggering relay action stage

[0120] Processing chip 5 (taking a DSP as an example, which has powerful digital signal processing capabilities and flexible control functions, and can accurately output control signals to meet circuit requirements) sends high-level control signals to Test_control 1 and Test_control 2 ports. The voltage value of this high-level signal exceeds the regulated voltage of 3.3V of the first Zener diode ZD1 and the second Zener diode ZD2.

[0121] In the circuit, the first Zener diode ZD1 and the first transistor Q1 form one control branch, and the second Zener diode ZD2 and the second transistor Q2 form another control branch. When the Test_control 1 port outputs a high level exceeding 3.3V, the first Zener diode ZD1 is reverse-biased, and its voltage stabilizes at 3.3V. At this time, the base of the first transistor Q1 receives sufficient forward bias voltage, causing Q1 to conduct. Because Q1 is conducting, the resistance between its collector and emitter becomes very small, effectively creating a closed circuit. This provides a current path for the coil of the first relay RLY1. Current flows through the coil of the first relay RLY1, generating an electromagnetic attraction that causes the first relay RLY1 to change from an open state to a closed state.

[0122] Similarly, when the Test_control 2 port outputs a high level exceeding 3.3V, the second Zener diode ZD2 is reverse-biased and breaks down, the second transistor Q2 conducts, and current flows through the coil of the second relay RLY2, causing RLY2 to change from an open state to a closed state. This process enables the processing chip 5 to precisely control the relays, laying the foundation for subsequent voltage sampling and presence detection.

[0123] II. Voltage Sampling Analysis Stage under Different In-Situ States

[0124] Current transformer CT 6 in place

[0125] When current transformer CT6 is in position, the circuit forms a specific resistor voltage divider network. The voltage sampled at the CT_TEST_AD+ and CT_TEST_AD- ports is determined by the voltage division of resistors R1, R2, and R5. According to the voltage divider principle of series circuits, the voltage across each resistor is proportional to its resistance value. Therefore, the voltage sampled at the CT_TEST_AD+ and CT_TEST_AD- ports is 3.3 × R2 / (R1 + R2). This is because in this voltage divider network, the ratio of the voltage across R2 to the total voltage (assuming the relevant power supply voltage is 3.3V after some conversion) is R2 / (R1 + R2), hence the sampled voltage is as expressed above.

[0126] Current transformer CT 6 not in place

[0127] When current transformer CT 6 is not in position, the resistor divider network of the circuit changes. At this time, the voltage sampled at the CT_TEST_AD+ and CT_TEST_AD- ports becomes 3.3 × R2 / (R1 + R2 + R5). This is because when current transformer CT 6 is not in position, resistor R5 participates in the voltage divider network, reducing the proportion of R2 in the total resistance, thus resulting in a lower sampled voltage.

[0128] Simultaneously, the CT_AD+ and CT_AD- ports also begin sampling voltage. In this voltage divider network, the voltage sampled by the CT_AD+ and CT_AD- ports is 3.3 × R5 / (R1 + R2 + R5). This is because the ratio of the voltage across R5 to the total voltage is R5 / (R1 + R2 + R5), hence the sampled voltage is expressed as this. By acquiring the voltage values ​​of these two ports under different conditions and comparing them with a preset threshold, the processing chip 5 can accurately determine whether the current transformer CT 6 is in position.

[0129] III. Relay Reset Phase

[0130] After the above detection steps are completed, the processing chip 5 controls the Test_control 1 and Test_control 2 ports to a low level. At this time, the voltage across the first Zener diode ZD1 and the second Zener diode ZD2 is lower than their regulated voltage of 3.3V, and they are no longer reverse-biased, equivalent to an open circuit. Therefore, the bases of the first transistor Q1 and the second transistor Q2 cannot obtain sufficient forward bias voltage, and neither the first transistor Q1 nor the second transistor Q2 conducts.

[0131] Since the first transistor Q1 and the second transistor Q2 are not conducting, there is no current path in the coils of the first relay RLY1 and the second relay RLY2, and no current flows through the coils, thus the electromagnetic attraction disappears. Under the action of the reset spring, both the first relay RLY1 and the second relay RLY2 change from the closed state to the open state, and the circuit returns to its initial state, ready for the next test.

[0132] In summary, this embodiment uses the processing chip 5 to precisely control the relay's operation, utilizes the principle of resistor voltage division to sample voltages under different in-position states, determines whether the current transformer CT 6 is in position based on the sampled voltage, and finally resets the relay through a control signal. The entire process is logically clear and precisely controlled, reliably realizing the in-position detection function of the current transformer CT 6.

[0133] Although this application frequently uses terms such as processing chip and current transformer, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

[0134] Example 2

[0135] The present invention provides a dual-sampling-based in-situ detection system, comprising a processing chip, a current transformer (CT), and a dual-sampling-based in-situ detection circuit as described in the present invention.

[0136] The processing chip is used to send control signals to the switch driving module so that the switch driving module generates a drive current;

[0137] The switch execution module is used to perform the action of closing the switch after receiving the drive current, so as to turn on the first voltage sampling module and the second voltage sampling module;

[0138] The first voltage sampling module is used to sample the voltage of the circuit where the switch execution module is located, and feed the first sampled voltage back to the processing chip;

[0139] The second voltage sampling module is used to sample the voltage of the current transformer (CT) and feed the second sampled voltage back to the processing chip;

[0140] The processing chip is also used to make the following judgments:

[0141] If the first sampled voltage is a first preset value, then the current transformer CT is determined to be in place; if the first sampled voltage is a second preset value and the second sampled voltage is a third preset value, then the current transformer CT is determined to be out of place.

[0142] In one embodiment of this invention, the processing chip is further configured to perform the following determination:

[0143] Before starting in-situ testing, first confirm the current sampling value of the current transformer CT and ensure that there is no current on the power line of the current transformer CT before starting in-situ testing.

[0144] The first sampling voltage is checked to see if it is 0V; if it is not 0V, the circuit has a fault and the detection is terminated; if the first sampling voltage is 0V, the next step is to send a control signal to the switch driver module so that the switch driver module generates a drive current.

[0145] It should be noted that the processing chip, as the core control unit of the entire system, undertakes the important tasks of sending control signals and performing logical judgments. It can be a chip with powerful processing capabilities and rich interfaces, such as a DSP (Digital Signal Processor), which can accurately control the operation of the system according to preset programs and logic.

[0146] The current transformer (CT) is the object of detection in this system. Its main function is to proportionally transform the large current on the primary side into a smaller current on the secondary side for measurement and protection. In this system, the on-state status of the current transformer (CT) is a key piece of information that needs to be monitored.

[0147] The CT presence detection circuit, as provided in Embodiment 1 of this invention, includes a switch driving module, a switch execution module, a first voltage sampling module, and a second voltage sampling module. Under the control of the processing chip, this circuit detects the presence status of the current transformer (CT).

[0148] The dual-sampling-based in-situ detection system provided in Embodiment 2 of this invention achieves efficient and accurate detection of the in-situ status of current transformers (CTs) through the coordinated operation of its modules. This system has advantages such as simple structure, high reliability, and low cost, and can be widely applied in fields such as power and industrial control.

[0149] Finally, it should be noted that although the above embodiments have been described in the text and drawings of this application, this should not limit the scope of patent protection of this application. Any technical solutions that are based on the essential concept of this application and utilize the content described in the text and drawings of this application, resulting in equivalent structural or procedural substitutions or modifications, as well as the direct or indirect application of the technical solutions of the above embodiments to other related technical fields, are all included within the scope of patent protection of this application.

Claims

1. An in-situ detection circuit based on dual sampling, characterized in that, It includes a switch driving module (1), a switch execution module (2), a first voltage sampling module (3), and a second voltage sampling module (4); wherein, The switch driving module (1) is connected to the processing chip (5) and is used to receive the control signal from the processing chip (5) to generate a driving current; The switch execution module (2) is connected to the switch drive module (1), the first voltage sampling module (3) and the second voltage sampling module (4) respectively, and is used to perform the action of closing the switch after receiving the drive current, so as to turn on the first voltage sampling module (3) and the second voltage sampling module (4). The first voltage sampling module (3) is connected to the processing chip (5) and is used to sample the voltage of the circuit where the switch execution module (2) is located after it is turned on, and to feed back the first sampled voltage to the processing chip (5). The second voltage sampling module (4) is connected to the current transformer CT (6) and the processing chip (5) respectively. It is used to sample the voltage of the current transformer CT (6) after it is turned on and feed back the second sampled voltage to the processing chip (5). If the first sampling voltage is a first preset value, then the current transformer CT (6) is determined to be in place; if the first sampling voltage is a second preset value and the second sampling voltage is a third preset value, then the current transformer CT (6) is determined to be out of place.

2. The in-situ detection circuit based on dual sampling according to claim 1, characterized in that, The switch drive module (1) includes a Test_control 1 port, a Test_control 2 port, a first Zener diode ZD1, a second Zener diode ZD2, a first transistor Q1, a second transistor Q2, a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4; The Test_control 1 port and the Test_control 2 port are respectively connected to the processing chip (5); The cathode of the first Zener diode ZD1 is connected to the Test_control 1 port, and the anode of the first Zener diode ZD1 is connected to the base of the first transistor Q1. The emitter of the first transistor Q1 is grounded; The positive terminal of the first diode D1 and the second diode D2 are connected in parallel and connected to the collector of the first transistor Q1, and the negative terminal is connected to the first auxiliary power supply. The negative terminal of the second Zener diode ZD2 is connected to the Test_control 2 port, and the positive terminal of the second Zener diode ZD2 is connected to the base of the second transistor Q2; The emitter of the second transistor Q2 is grounded; The positive terminal of the third diode D3 and the fourth diode D4 are connected in parallel and connected to the collector of the second transistor Q2, while the negative terminal is connected to the first auxiliary power supply.

3. The in-situ detection circuit based on dual sampling according to claim 2, characterized in that, The switch driving module (1) also includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4; The first resistor R1 and the first capacitor C1 are connected in parallel. One end of the first resistor R1 is connected to the base of the first transistor Q1, and the other end is connected to the emitter of the first transistor Q1. The second resistor R2 is connected in series between the positive terminal of the first Zener diode ZD1 and the base of the first transistor Q1; One end of the second capacitor C2 is connected to the first auxiliary power supply, and the other end is grounded; The third resistor R3 and the third capacitor C3 are connected in parallel. One end of the connection is connected to the base of the second transistor Q2, and the other end is connected to the emitter of the second transistor Q2. The fourth resistor R4 is connected in series between the positive terminal of the second Zener diode ZD2 and the base of the second transistor Q2; One end of the fourth capacitor C4 is connected to the first auxiliary power supply, and the other end is grounded.

4. The in-situ detection circuit based on dual sampling according to claim 2, characterized in that, The switch execution module (2) includes a first relay RLY1, a second relay RLY2, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and a fifth diode D5; The coil of the first relay RLY1 is connected in parallel to the first diode D1 and the second diode D2. The moving contact of the first relay RLY1 is connected to the second auxiliary power supply after being connected in series with the seventh resistor R7 and the fifth resistor R5. The stationary contact of the first relay RLY1 is connected to the first end of the secondary side of the current transformer CT (6). The coil of the second relay RLY2 is connected in parallel to the third diode D3 and the fourth diode D4. The moving contact of the second relay RLY2 is connected to the positive terminal of the fifth diode D5. The stationary contact of the first relay RLY1 is connected to the second terminal of the secondary side of the current transformer CT (6). The negative terminal of the fifth diode D5 is connected to the first terminal of the secondary side of the current transformer CT (6); The sixth resistor R6 is connected in parallel across the two ends of the secondary side of the current transformer CT (6); The second terminal of the secondary side of the current transformer CT (6) is grounded.

5. The in-situ detection circuit based on dual sampling according to claim 4, characterized in that, The first voltage sampling module (3) includes a CT_TEST_AD+ port and a CT_AD- port; The CT_TEST_AD+ port is connected to the first end of the seventh resistor R7 and the processing chip (5) respectively; The CT_AD-port is connected to the second end of the seventh resistor R7 and the processing chip (5).

6. The in-situ detection circuit based on dual sampling according to claim 5, characterized in that, The second voltage sampling module (4) includes a CT_AD+ port and a CT_AD- port; The CT_AD+ port is connected to the first end of the secondary side of the current transformer CT (6) and the processing chip (5), respectively. The CT_AD-port is connected to the second end of the secondary side of the current transformer CT (6) and the processing chip (5).

7. The in-situ detection circuit based on dual sampling according to claim 6, characterized in that, The first auxiliary power supply provides a +12V voltage; The second auxiliary power supply provides a voltage of +3.3V.

8. The in-situ detection circuit based on dual sampling according to claim 7, characterized in that, The first Zener diode ZD1 and the second Zener diode ZD2 are 3.3V Zener diodes.

9. An in-situ detection system based on dual sampling, characterized in that, It includes a processing chip, a current transformer (CT), and an in-situ detection circuit based on dual sampling as described in any one of claims 1-8; The processing chip is used to send control signals to the switch driving module so that the switch driving module generates a drive current; The switch execution module is used to perform the action of closing the switch after receiving the drive current, so as to turn on the first voltage sampling module and the second voltage sampling module; The first voltage sampling module is used to sample the voltage of the circuit where the switch execution module is located, and feed the first sampled voltage back to the processing chip; The second voltage sampling module is used to sample the voltage of the current transformer (CT) and feed the second sampled voltage back to the processing chip; The processing chip is also used to make the following judgments: If the first sampled voltage is a first preset value, then the current transformer CT is determined to be in place; if the first sampled voltage is a second preset value and the second sampled voltage is a third preset value, then the current transformer CT is determined to be out of place.

10. The in-situ detection system based on dual sampling according to claim 9, characterized in that, The processing chip is also used to make the following judgments: Before starting in-situ testing, first confirm the current sampling value of the current transformer CT and ensure that there is no current on the power line of the current transformer CT before starting in-situ testing. Detect whether the first sampling voltage is 0V; If the voltage is not 0V, the circuit is faulty and the detection is terminated; if the first sampling voltage is 0V, the next step is to send a control signal to the switch driver module so that the switch driver module generates a drive current.

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