Industrial control board card power supply method based on two-stage voltage stabilization and multi-stage protection

Abstract

The application relates to the technical field of power supply control, and discloses an industrial control board card power supply method based on two-stage voltage stabilization and multi-stage protection, which is applied to a two-stage cascaded voltage stabilization power supply chain of an industrial control board card and comprises the following steps: taking a first-stage voltage stabilization output as a second-stage voltage stabilization input, keeping the cascaded power supply connection unchanged during acquisition of an inlet voltage, a first-stage voltage and a second-stage voltage; obtaining an inlet voltage relative deviation, a first-stage voltage relative deviation and a second-stage voltage relative deviation according to an inlet nominal voltage, a first-stage nominal voltage and a second-stage nominal voltage respectively, comparing the three in a power supply direction, and determining a step-by-step convergence relationship or a non-step-by-step convergence relationship according to whether the three are step-by-step non-increased or not step-by-step increased; under the step-by-step convergence relationship, making the first-stage voltage stabilization conversion continue, and under the non-step-by-step convergence relationship, making the first-stage voltage stabilization conversion stop. The application is used for industrial control board card power supply control.

Description

Technical Field

[0001] This invention relates to the field of power supply control technology, and more specifically, to a power supply method for industrial control boards based on two-stage voltage regulation and multi-stage protection. Background Technology

[0002] Industrial control boards are typically installed in power distribution cabinets, field devices, or production line control units, and are mostly powered by field DC power. These boards must convert the field power supply to multiple voltage levels required by control chips, communication interfaces, and digital circuits. They also need to handle power supply disturbances caused by reverse wiring, surges, electromagnetic interference, and load variations. Therefore, in engineering practice, reverse connection protection and transient suppression are often implemented at the input, filtering stages are set before and after voltage regulation, and multiple voltage levels are supplied through pre-conversion and post-regulation.

[0003] In actual operation, the power supply input, the first-stage voltage regulator output, and the second-stage voltage regulator output correspond to different nominal levels. If only a single voltage point is observed, or voltage values ​​at different levels are directly compared, it is difficult to determine whether disturbances are gradually converged along the power supply direction in the cascaded power supply chain. Furthermore, this judgment cannot be reliably used to control the continuation or cessation of the preceding stage's voltage regulation. Another common situation in field maintenance is that input-side interference, after protection and filtering, can still be transmitted to the subsequent stage. Changes in the load of the subsequent stage can then negatively affect the operating state of the preceding stage. Single-point detection provides insufficient control basis, easily causing the preceding stage to continue operating under unsuitable power supply conditions.

[0004] Therefore, the power supply control of industrial control boards requires a processing method for a two-stage cascaded voltage regulation power supply chain, so that the power supply input, the first-stage voltage regulation output and the second-stage voltage regulation output can still form a comparable relationship along the power supply direction under different nominal levels, and that this relationship can directly participate in the continuation or cessation control of the first-stage voltage regulation transformation. Summary of the Invention

[0005] This invention provides a power supply method for industrial control boards based on two-stage voltage regulation and multi-stage protection, which solves the technical problems mentioned in the background art.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution.

[0007] A power supply method for industrial control boards based on two-stage voltage regulation and multi-stage protection is provided. This method involves a two-stage cascaded voltage-regulating power supply chain for industrial control boards. The two-stage cascaded voltage-regulating power supply chain includes a power input, a first-stage regulated output, and a second-stage regulated output along the power supply direction. The method includes: Use the output of the first-stage regulator as the input of the second-stage regulator; During the acquisition of input voltage, first-stage voltage, and second-stage voltage, the cascaded power supply connection between the power supply input, the first-stage regulated output, and the second-stage regulated output remains unchanged. Based on the nominal inlet voltage, the primary nominal voltage, and the secondary nominal voltage, the relative deviations of the inlet voltage, the primary voltage, and the secondary voltage are determined respectively. The relative deviations of the inlet voltage, the primary voltage, and the secondary voltage respectively characterize the degree of deviation of the inlet voltage from the nominal inlet voltage, the primary voltage from the primary nominal voltage, and the secondary voltage from the secondary nominal voltage. The relative deviations of the input voltage, the first-level voltage, and the second-level voltage are compared along the power supply direction. The comparison results in which the relative deviations of the input voltage, the first-level voltage, and the second-level voltage do not increase step by step along the power supply direction are determined as step-by-step convergence relationships, and other comparison results are determined as non-step-by-step convergence relationships. When the relationship is determined to be a stepwise convergence relationship, the first-stage voltage regulation transformation continues; when the relationship is determined to be a non-stepwise convergence relationship, the first-stage voltage regulation transformation stops.

[0008] Compared with the prior art, the present invention has the following substantial features and significant progress: This invention, within a two-stage cascaded voltage regulation power supply chain of an industrial control board, uses the actual voltages of the power supply input, the first-stage voltage regulator output, and the second-stage voltage regulator output as the objects. It transforms voltages at different nominal levels into relative deviations that can be compared along the power supply direction, and directly uses the comparison results to control the continuation or termination of the first-stage voltage regulation conversion. In this way, power supply judgment remains within the industrial control board's power supply path itself. While retaining reverse connection protection, transient suppression, and filtering, it connects the upstream conversion control with the output states of both stages, reducing the insufficient control basis caused by relying solely on single-point voltage judgments, and providing a clearer control foundation for powering multi-voltage level loads. Attached Figure Description

[0009] Figure 1 This is an architecture diagram of the power supply method for industrial control boards based on two-stage voltage regulation and multi-stage protection according to the present invention. Detailed Implementation

[0010] The following description is provided in conjunction with the accompanying drawings. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the invention; those skilled in the art can make equivalent substitutions or combinations for the specific implementations.

[0011] This embodiment relates to the field of power supply control, specifically to a power supply method for industrial control boards based on two-stage voltage regulation and multi-stage protection. When industrial control boards are used in field devices, distribution cabinets, or production line control units, it is usually necessary to convert the DC power supplied by the industrial site into operating power supplies of different voltage levels within the industrial control board. Since the wiring status, surge status, high-frequency interference status, and load variation status of the industrial site can affect the power supply path, this embodiment sets up a two-stage cascaded voltage-regulating power supply chain arranged along the power supply direction within the industrial control board. The input voltage, first-stage voltage, and second-stage voltage are obtained from the two-stage cascaded voltage-regulating power supply chain, and then the relative deviations of the input voltage, first-stage voltage, and second-stage voltage are determined, so that voltages at different nominal voltage levels can form a comparable inter-stage deviation relationship.

[0012] The two-stage cascaded voltage regulator power supply chain includes a power supply input, a first-stage voltage regulator output, and a second-stage voltage regulator output along the power supply direction. The power supply input receives DC power from the industrial site; the first-stage voltage regulator output is the output node after the first-stage voltage transformation; and the second-stage voltage regulator output is the output node formed by the second-stage voltage regulation stage. The first-stage voltage regulator output serves as the input for the second-stage voltage regulation, making the power supply input, the first-stage voltage regulator output, and the second-stage voltage regulator output three nodes in the same continuous power supply path. Through this cascaded relationship, the input voltage, the first-stage voltage, and the second-stage voltage are not isolated measurements, but rather three voltages that reflect the power supply status of the industrial control board along the power supply direction.

[0013] In this embodiment, a reverse connection protection diode, a transient suppression diode, an input filter network, a first-stage switching DC-DC converter, and a second-stage low-dropout linear regulator can be sequentially configured after the power supply input. The reverse connection protection diode is used to conduct when the input polarity is correct and to cut off when the input polarity is reversed; the transient suppression diode is placed between the input node and ground after the reverse connection protection to clamp the voltage in the event of transient overvoltage or surge; the input filter network is placed on the input side of the first-stage switching DC-DC converter to suppress high-frequency interference entering the first-stage switching DC-DC converter; the first-stage switching DC-DC converter performs the first-stage voltage regulation conversion; the second-stage low-dropout linear regulator receives the first-stage regulated output and forms the second-stage regulated output.

[0014] In this embodiment, voltage acquisition can be performed by a voltage acquisition unit on an industrial control board. The voltage acquisition unit obtains the input voltage from the acquisition position corresponding to the power supply input, the first-stage voltage from the acquisition position corresponding to the first-stage regulated output, and the second-stage voltage from the acquisition position corresponding to the second-stage regulated output. During the acquisition of the input voltage, first-stage voltage, and second-stage voltage, the cascaded power supply connection between the power supply input, the first-stage regulated output, and the second-stage regulated output remains unchanged, ensuring that the acquired input voltage, first-stage voltage, and second-stage voltage reflect the power supply status of the two-stage cascaded voltage regulator chain under actual power supply connection conditions.

[0015] Furthermore, a two-stage cascaded voltage regulation power supply chain is formed, as follows: Specifically, a two-stage cascaded voltage regulator power supply chain is formed. This chain is a power supply path installed in the industrial control board, comprising a power input, a first-stage regulated output, and a second-stage regulated output along the power supply direction. The power supply direction is from the DC power supplied from the industrial site, entering the industrial control board and flowing through the power input to the subsequent voltage regulation stage. The first-stage regulated output is located after the power input, and the second-stage regulated output is located after the first-stage regulated output. The two-stage cascaded voltage regulator power supply chain does not simply mean the two voltage regulators exist in parallel; rather, it means that the first-stage regulated output serves as the input for the second-stage regulated output, creating a power supply continuity between them.

[0016] In one specific implementation, the DC power supply provided at the industrial site is connected to the power supply input of the industrial control board. The power supply input can be a power terminal on the board, a connector input pin, or an equivalent power input node. This DC power supply serves as the input source for subsequent reverse connection protection, transient suppression, input filtering, and two-stage voltage regulation. After entering the power supply input, the DC power supply passes through the reverse connection protection diode along the power supply direction before reaching the input node after reverse connection protection. The input node after reverse connection protection is connected to both the branch containing the transient suppression diode and the input filter network, ensuring that the reverse connection protection diode, transient suppression diode, and input filter network are within the input-side power supply path before the first-stage voltage regulation transformation.

[0017] The first-stage voltage regulation conversion can be performed by a first-stage switching DC-DC converter. The input side of the first-stage switching DC-DC converter receives the DC voltage output from the input filter network, and its output side forms the first-stage regulated output. This first-stage regulated output can supply power to loads in industrial control boards that require this voltage level, and also serves as the input to a second-stage low-dropout linear regulator. The second-stage low-dropout linear regulator forms its second-stage regulated output based on the second-stage regulated input. Thus, the power supply input, the first-stage regulated output, and the second-stage regulated output are organized in the same two-stage cascaded voltage regulation power supply chain, and the three are arranged sequentially along the power supply direction.

[0018] In this embodiment, the specific voltage levels are 24V DC voltage corresponding to the power supply input, 5V DC voltage corresponding to the first-stage regulated output, and 3.3V DC voltage corresponding to the second-stage regulated output. At this specific voltage level, the power supply input receives 24V DC power from the industrial site. The first-stage switching DC-DC converter steps down the filtered 24V DC voltage and outputs 5V DC voltage. The second-stage low-dropout linear regulator further regulates the 5V DC voltage to 3.3V DC voltage.

[0019] Furthermore, a reverse connection protection diode, a transient suppression diode, and an input filter network are configured, as follows: Specifically, before obtaining the input voltage, the DC power supplied from the industrial site is routed through a reverse polarity protection diode into the subsequent power supply path of the two-stage cascaded voltage regulator chain. The reverse polarity protection diode is connected in series after the power input, with its anode and cathode arranged according to the forward power supply direction of the industrial control board. When the input polarity is correct, the reverse polarity protection diode conducts, allowing the DC power supplied from the industrial site to be sent to the subsequent power supply path; when the input polarity is reversed, the reverse polarity protection diode cuts off and blocks reverse current, thereby preventing reverse current from entering the subsequent voltage regulator circuit.

[0020] In this embodiment, the reverse connection protection diode is positioned to match the acquisition of the input voltage. The power supply input is located where the industrial control board receives DC power from the industrial site, and the reverse connection protection diode is located after the power supply input. Since the input voltage is obtained from the acquisition position corresponding to the power supply input, the input voltage can reflect the voltage state when the DC power supplied from the industrial site enters the industrial control board. When the reverse connection protection diode is turned on, the subsequent power supply path after the power supply input receives forward power; when the reverse connection protection diode is turned off, the subsequent power supply path does not bear reverse current.

[0021] A transient suppression diode is installed between the input node after reverse connection protection and ground. The input node after reverse connection protection is located on the output side of the reverse connection protection diode and on the input side of the input filter network. One end of the transient suppression diode is connected to the input node after reverse connection protection, and the other end is connected to ground. When a transient overvoltage or surge occurs at the input node after reverse connection protection, the transient suppression diode clamps the surge, releasing or limiting it through the grounding branch to a range that the subsequent power supply path can withstand. This setup is a common transient suppression implementation method on the input side of industrial control boards, based on the common working mechanism of the transient suppression diode limiting the voltage across its terminals when it is reverse avalanche conduction.

[0022] The input filter network is located on the input side of the first-stage switching DC-DC converter and consists of an inductor and an input filter capacitor. The inductor is connected in series in the input power supply path, and the input filter capacitor is connected between the input power supply path and ground. Together, the inductor and the input filter capacitor suppress high-frequency interference entering the first-stage switching DC-DC converter. The output side of the input filter network is connected to the input side of the first-stage switching DC-DC converter. Therefore, the input filter network is located both at the front end of the two-stage cascaded voltage regulator power supply chain and at the input of the first-stage voltage regulator.

[0023] In one specific implementation, the voltage at the input node after reverse connection protection can be fed into an input filter network composed of an inductor and an input filter capacitor. The inductor provides impedance to high-frequency current changes, and the input filter capacitor provides a bypass path to ground for high-frequency components. After the DC power supplied in the industrial field passes through the input filter network, the input filter network suppresses high-frequency interference entering the first-stage switching DC-DC converter.

[0024] Furthermore, the first-stage voltage regulation and transformation is performed to form the first-stage regulated output, as follows: Specifically, the first-stage voltage regulation is performed by a first-stage switching DC-DC converter. This first-stage switching DC-DC converter receives the DC voltage output from the input filter network and forms the first-stage regulated output through a switching conversion method. In one specific embodiment, the first-stage switching DC-DC converter steps down the filtered 24V DC voltage and outputs a 5V DC voltage. This 5V DC voltage corresponds to the first-stage regulated output and serves as the specific voltage level corresponding to the first-stage nominal voltage.

[0025] The first-stage voltage regulator converts the higher voltage level at the power input side into a first-stage regulated output suitable for subsequent power supply paths on industrial control boards. This first-stage regulated output then serves as the input to the second-stage low-dropout linear regulator. Therefore, the first-stage regulated output fulfills two roles: firstly, it acts as an intermediate power supply node in the two-stage cascaded voltage regulation chain; secondly, it provides the power source for the subsequent second-stage regulated output.

[0026] The first-stage switching DC-DC converter can be implemented using a conventional step-down switching regulator structure found on industrial control boards. Its input is connected to the output side of the input filter network, and its output is connected to the corresponding output terminal of the first-stage regulator. The first-stage switching DC-DC converter forms a step-down output through internal switching transistors, energy storage inductors, freewheeling paths, and output-side energy storage elements. The specific models, inductance values, and capacitance values ​​of these components can be determined according to the load requirements and voltage levels of the industrial control board using conventional power supply design methods.

[0027] A first-stage output filter capacitor is installed at the output terminal corresponding to the first-stage regulated output. This capacitor is connected between the output terminal and ground to smooth the switching ripple on the output side of the first-stage switching DC-DC converter. The location of the first-stage output filter capacitor corresponds to the sampling location of the first-stage voltage, ensuring that the voltage obtained from the sampling location corresponding to the first-stage regulated output reflects the power supply state of the first-stage regulated output after output filtering.

[0028] While the first-stage switching DC-DC converter is in the conversion state, the first-stage voltage regulation continues, and the DC voltage output from the input filter network is continuously converted into the first-stage regulated output. If the control decision unit determines that the relationship is one of successive convergence, the first-stage voltage regulation continues; if the control decision unit determines that the relationship is not one of successive convergence, the first-stage voltage regulation stops.

[0029] Furthermore, a second stage of regulated output is formed, as detailed below: The fourth step involves using the first-stage regulated output as the input to the second-stage regulated output, and then using the output of the second-stage low-dropout linear regulator to form the second-stage regulated output. The input of the second-stage low-dropout linear regulator is connected to the first-stage regulated output, and its output forms the second-stage regulated output. In one specific embodiment, the second-stage low-dropout linear regulator regulates the 5V DC voltage corresponding to the first-stage regulated output to a 3.3V DC voltage. This 3.3V DC voltage corresponds to the second-stage regulated output and serves as the specific voltage level corresponding to the second-stage nominal voltage.

[0030] The formation of the second-stage regulated output provides a complete downstream power supply node for the two-stage cascaded voltage regulator power supply chain. Since the second-stage regulated output is generated by the output of a second-stage low-dropout linear regulator, and the first-stage regulated output is fed into the second-stage low-dropout linear regulator, there is an input-output relationship between the second-stage and first-stage regulated outputs. According to its linear regulation mechanism, the second-stage low-dropout linear regulator adjusts the second-stage regulated input to become the second-stage regulated output when the second-stage regulated input meets its operating requirements.

[0031] The input side of the second-stage low-dropout linear regulator is connected to the output of the first-stage regulator, and its output side is connected to the corresponding output terminal of the second-stage regulator. A second-stage output filter capacitor is placed at the corresponding output terminal of the second-stage regulator. The second-stage output filter capacitor is connected between the corresponding output terminal of the second-stage regulator and ground to smooth the second-stage regulator output. The location of the second-stage output filter capacitor corresponds to the sampling location of the second-stage voltage, so that when the second-stage voltage is obtained from the sampling location corresponding to the second-stage regulator output, it can reflect the power supply state of the second-stage regulator output after output filtering.

[0032] The connection between the first-stage regulated output and the second-stage regulated input is a prerequisite for subsequently comparing the relative deviations of the input voltage, the first-stage voltage, and the second-stage voltage along the power supply direction. The input voltage corresponds to the power supply input, the first-stage voltage corresponds to the first-stage regulated output, and the second-stage voltage corresponds to the second-stage regulated output. When the second-stage regulated output is formed by the output of the second-stage low-dropout linear regulator, the second-stage voltage reflects the result of the first-stage regulated output after passing through the second-stage low-dropout linear regulator.

[0033] In the specific power supply process, the first-stage voltage regulator output can be reserved to provide power to the loads in the industrial control board that require 5V DC voltage, while the second-stage voltage regulator output can provide 3.3V DC voltage to the MCU and digital circuits.

[0034] Furthermore, the input voltage, primary voltage, and secondary voltage are obtained, as follows: Specifically, during the acquisition of the input voltage, primary voltage, and secondary voltage, the cascaded power supply connection between the power supply input, the first-stage regulated output, and the second-stage regulated output remains unchanged. This unchanged cascaded power supply connection means that when acquiring the input voltage, primary voltage, and secondary voltage, the power supply connection from the power supply input to the first-stage regulated output, and the power supply connection from the first-stage regulated output to the second-stage regulated output, are not disconnected, ensuring that the three voltages are acquired under the actual operating conditions of the same two-stage cascaded voltage regulation power supply chain.

[0035] The input voltage is obtained from the acquisition location corresponding to the power supply input. This acquisition location can be set at the power supply input terminal or at an equivalent node that characterizes the power supply input voltage state. The input voltage represents the voltage state when the DC power supplied in the industrial field enters the industrial control board. Since the input voltage corresponds to the nominal input voltage, the relative deviation of the input voltage can be determined based on the input voltage and the nominal input voltage, allowing the input voltage to be converted to a relative deviation scale when comparing different nominal voltage levels.

[0036] The primary voltage is obtained from the sampling point corresponding to the first-stage regulated output. This sampling point can be set on the output side of the first-stage switching DC-DC converter, located on the power supply path from the first-stage regulated output to the second-stage low-dropout linear regulator. The primary voltage represents the voltage state after the first-stage voltage regulation. Since the primary voltage corresponds to the primary nominal voltage, the relative deviation of the primary voltage can be determined based on the primary voltage and the primary nominal voltage, allowing the primary voltage to be compared with the input voltage and the secondary voltage in a relative deviation comparison.

[0037] The secondary voltage is obtained from the sampling location corresponding to the output of the second-stage regulated voltage. This sampling location can be set on the output side of the second-stage low-dropout linear regulator. The secondary voltage represents the voltage state of the second-stage regulated output. Since the secondary voltage corresponds to the second-stage nominal voltage, the relative deviation of the secondary voltage can be determined based on the secondary voltage and the second-stage nominal voltage, allowing the secondary voltage to be compared with the input voltage and the first-stage voltage in a relative deviation comparison.

[0038] In one specific implementation, the input voltage, primary voltage, and secondary voltage can be acquired at the same sampling moment. The same sampling moment indicates that the input voltage, primary voltage, and secondary voltage correspond to the same power supply state within the same control cycle. The voltage acquisition unit on the industrial control board can acquire the three voltages through a multi-channel analog-to-digital converter, a sample-and-hold circuit, or an equivalent acquisition circuit. For cases where a single analog-to-digital converter polls multiple acquisition channels, the acquired input voltage, primary voltage, and secondary voltage can be aligned to the same sampling moment through sample-and-hold or time alignment within the control cycle.

[0039] When acquiring the input voltage, first-stage voltage, and second-stage voltage, the voltage acquisition unit does not alter the cascaded power supply connection between the power supply input, the first-stage regulated output, and the second-stage regulated output. The voltage acquisition unit can obtain the voltage at each acquisition point through voltage divider sampling, voltage follower, or analog-to-digital conversion input channels. To avoid affecting the power supply status of the two-stage cascaded regulated power supply chain, the acquisition circuit presents a high input impedance relative to the acquired node. This high input impedance acquisition method is a common engineering measure in voltage detection of industrial control boards, used to ensure that the acquisition process does not change the power supply connection relationship of the acquired node.

[0040] Furthermore, the relative deviations of the input voltage, the first-stage voltage, and the second-stage voltage are determined as follows: Specifically, based on the nominal inlet voltage, the primary nominal voltage, and the secondary nominal voltage, the relative deviations of the inlet voltage, the primary voltage, and the secondary voltage are determined respectively. The nominal inlet voltage is the nominal voltage corresponding to the inlet voltage, the primary nominal voltage is the nominal voltage corresponding to the primary voltage, and the secondary nominal voltage is the nominal voltage corresponding to the secondary voltage. Since the inlet voltage, primary voltage, and secondary voltage are at different nominal voltage levels, directly comparing the voltage values ​​themselves cannot reflect the degree of deviation of each node from its respective nominal voltage. Therefore, this embodiment converts the three voltages into their respective deviations from the nominal voltage.

[0041] The relative deviation of the input voltage characterizes the degree of deviation of the input voltage from the nominal input voltage. The relative deviation of the first-level voltage characterizes the degree of deviation of the first-level voltage from the first-level nominal voltage. The relative deviation of the second-level voltage characterizes the degree of deviation of the second-level voltage from the second-level nominal voltage. By determining the relative deviations of the input voltage, the first-level voltage, and the second-level voltage separately, the actual voltages at different voltage levels such as 24V, 5V, and 3.3V can be converted to the same relative scale, allowing for comparison along the power supply direction.

[0042] In one specific embodiment, the nominal inlet voltage is 24, the primary nominal voltage is 5, and the secondary nominal voltage is 3.3. The inlet voltage is used... This indicates that the first-level voltage is used This indicates that the secondary voltage is used Indicated. Based on the input voltage, primary voltage, and secondary voltage, the power supply point is constructed. : ,in, Indicates the power supply point; Indicates the input voltage; Indicates the first-level voltage; The value 24 represents the nominal inlet voltage in this specific embodiment; the value 5 represents the nominal first-level voltage in this specific embodiment; and the value 3.3 represents the nominal second-level voltage in this specific embodiment. The signed component representing the relative deviation of the input voltage; The signed component representing the relative deviation of the first-level voltage; The signed component representing the relative deviation of the secondary voltage.

[0043] Power supply point The three components are arranged according to the power supply direction of the input voltage, primary voltage, and secondary voltage in a two-stage cascaded voltage regulator power supply chain. The first component originates from the input voltage and the input nominal voltage; the second component originates from the primary voltage and the primary nominal voltage; and the third component originates from the secondary voltage and the secondary nominal voltage. Power Supply Point It is a data representation that organizes the relative deviation of the input voltage, the relative deviation of the first-level voltage, and the relative deviation of the second-level voltage.

[0044] When determining the relative deviations of the inlet voltage, the first-level voltage, and the second-level voltage, each nominal voltage corresponds one-to-one with its corresponding voltage. The inlet voltage can only correspond to the nominal inlet voltage, the first-level voltage can only correspond to the nominal first-level voltage, and the second-level voltage can only correspond to the nominal second-level voltage.

[0045] Furthermore, determine whether the convergence relationship is gradual or non-gradual, as follows: Specifically, the relative deviations of the input voltage, the first-stage voltage, and the second-stage voltage are compared along the power supply direction. The power supply direction is from the power supply input to the first-stage regulated output and then to the second-stage regulated output. Therefore, the comparison order is: relative deviation of the input voltage, relative deviation of the first-stage voltage, and relative deviation of the second-stage voltage.

[0046] In one specific implementation, when the power supply point A relationship is considered a stepwise convergence relationship when the following conditions are met: ,in, Indicates the magnitude of the relative deviation of the input voltage; This indicates the magnitude of the relative deviation of the first-level voltage; This indicates the magnitude of the relative deviation of the secondary voltage. This relationship means that the relative deviation of the input voltage, the relative deviation of the primary voltage, and the relative deviation of the secondary voltage do not increase progressively along the power supply direction. In other words, from the power supply input to the first-stage regulated output and then to the second-stage regulated output, the degree of deviation does not increase along the power supply direction.

[0047] The comparison results of the relative deviations of the input voltage, the first-stage voltage, and the second-stage voltage not increasing along the power supply direction are determined as the step-by-step convergence relationship. The step-by-step convergence relationship indicates that the inter-stage deviation relationship in a two-stage cascaded voltage regulator chain conforms to a state of step-by-step convergence from the power supply input to the output of the next stage. In this state, the relative deviation of the first-stage voltage is no greater than the relative deviation of the input voltage, and the relative deviation of the second-stage voltage is no greater than the relative deviation of the first-stage voltage. Therefore, the step-by-step convergence relationship can serve as the control basis for continuing the first-stage voltage regulation transformation.

[0048] Other comparison results are defined as non-sequential convergence relationships. Other comparison results refer to those where the relative deviation of the input voltage, the relative deviation of the first-stage voltage, and the relative deviation of the second-stage voltage do not satisfy the requirement of not increasing at each stage along the power supply direction. For example, if the relative deviation of the first-stage voltage is greater than the relative deviation of the input voltage, or if the relative deviation of the second-stage voltage is greater than the relative deviation of the first-stage voltage, the above-mentioned non-increasing relationship is not satisfied. Non-sequential convergence relationships are used to indicate that the inter-stage deviation relationship in a two-stage cascaded voltage regulation power supply chain does not exhibit a state of sequential convergence from the power supply input to the output of the subsequent stage.

[0049] The control and decision unit can receive the input voltage relative deviation, first-level voltage relative deviation, and second-level voltage relative deviation output from the relative deviation determination unit, and perform comparisons according to the power supply direction. The relative deviation determination unit is responsible for determining the three relative deviations based on the input nominal voltage, first-level nominal voltage, and second-level nominal voltage; the control and decision unit is responsible for converting the comparison results of the three relative deviations into a step-by-step convergence relationship or a non-step-by-step convergence relationship. Data transmission between the voltage acquisition unit, the relative deviation determination unit, and the control and decision unit can be achieved through the controller, analog-to-digital conversion module, and digital processing module within the industrial control board.

[0050] Furthermore, the first-stage voltage regulation transformation is controlled according to the stepwise convergence relationship or the non-stepwise convergence relationship, as follows: Specifically, when a step-by-step convergence relationship is determined, the first-stage voltage regulation conversion continues; when a non-step-by-step convergence relationship is determined, the first-stage voltage regulation conversion stops. "Continuing the first-stage voltage regulation conversion" means that the first-stage switching DC-DC converter remains in the switching state, allowing the DC voltage output from the input filter network to continue forming the first-stage regulated output through the first-stage switching DC-DC converter. "Stopping the first-stage voltage regulation conversion" means controlling the first-stage switching DC-DC converter to stop switching, thus ceasing the continuous formation of the first-stage regulated output.

[0051] When the control decision unit determines that the relationship is one-to-one convergence, the relative deviation of the input voltage, the relative deviation of the first-stage voltage, and the relative deviation of the second-stage voltage do not increase step by step along the power supply direction. Therefore, under the current power supply conditions corresponding to the input voltage, the first-stage voltage, and the second-stage voltage, the inter-stage deviation relationship of the two-stage cascaded voltage regulator power supply chain satisfies the condition that the deviation does not increase step by step from the power supply input to the output of the next stage. Therefore, the control decision unit provides a control signal to the first-stage switching DC-DC converter to continue the conversion, so that the first-stage voltage regulation conversion continues. After the first-stage voltage regulation conversion continues, the first-stage regulated output continues to serve as the input for the second-stage regulated output, and the second-stage low-dropout linear regulator continues to form the second-stage regulated output.

[0052] When the control decision unit determines that the relationship is not progressively convergent, the relative deviations of the input voltage, the first-stage voltage, and the second-stage voltage do not satisfy the comparison relationship of not increasing progressively along the power supply direction. Therefore, under the current power supply conditions corresponding to the input voltage, first-stage voltage, and second-stage voltage, the inter-stage deviation relationship of the two-stage cascaded voltage regulation power supply chain does not show progressive convergence. Therefore, the control decision unit provides a control signal to the first-stage switching DC-DC converter to stop the switching conversion, thus stopping the first-stage voltage regulation conversion. After the first-stage voltage regulation conversion stops, the continuous supply of the two-stage regulated power supply to the board load ceases.

[0053] During the power supply period when the first-stage switching DC-DC converter is in the switching state, the reverse protection diode continues to block the reverse input, the transient suppression diode continues to limit input spikes, the input filter network continues to suppress high-frequency interference entering the first-stage switching DC-DC converter, and the first-stage output filter capacitor and the second-stage output filter capacitor smooth the first-stage regulated output and the second-stage regulated output, respectively. The above continuous operation process illustrates the coordination relationship between protection, filtering, and two-stage voltage regulation during the power supply of the industrial control board. However, the criterion for determining whether the first-stage voltage regulation continues or stops is still based on whether the relationship is one of successive convergence or non-successive convergence.

[0054] The control decision unit can control the first-stage voltage regulation converter through the enable terminal, control input terminal, or equivalent switching conversion control terminal. For a first-stage switching DC-DC converter, the control signal to continue conversion can maintain its enabled state, and the control signal to stop switching conversion can cancel its enabled state. This control interface belongs to the common control mode of the first-stage switching DC-DC converter, used to determine whether the stage-by-stage convergence relationship or non-stage-by-stage convergence relationship is to be continued or stopped.

[0055] In a complete control cycle, the power input of the industrial control board receives a 24V DC power supply from the industrial site. This 24V DC power supply first passes through a reverse connection protection diode.

[0056] When the input polarity is correct, the reverse connection protection diode is turned on, and the DC power supply enters the subsequent power supply path; after the reverse connection protection, the transient suppression diode set between the input node and ground is in a position that can clamp transient overvoltage or surge; the input filter network receives the DC voltage after the reverse connection protection, and the inductor and the input filter capacitor suppress the high-frequency interference entering the first-stage switching DC-DC converter.

[0057] In the At the start of each control cycle, the cascaded power supply connection between the power input, the first-stage voltage regulator output, and the second-stage voltage regulator output remains unchanged. The voltage acquisition unit obtains the input voltage, the first-stage voltage, and the second-stage voltage at the same sampling moment. Assume the input voltage obtained in this control cycle is... The voltage is 24.72V, which is the first-stage voltage. The voltage is 5.08V, and the secondary voltage is obtained. The nominal voltage is 3.34V. The nominal voltage at the input is 24V, the nominal voltage for the first stage is 5V, and the nominal voltage for the second stage is 3.3V.

[0058] Subsequently, the relative deviation determination unit determines the relative deviation of the inlet voltage, the relative deviation of the first-stage voltage, and the relative deviation of the second-stage voltage based on the nominal inlet voltage, the nominal first-stage voltage, and the nominal second-stage voltage, respectively. The relative deviation of the inlet voltage corresponds to... The calculated result is 0.03; the relative deviation of the first-level voltage corresponds to The calculated result is 0.016; the relative deviation of the secondary voltage corresponds to The calculated result is approximately 0.0121. Power supply point. The three signed components are 0.03, 0.016 and approximately 0.0121, respectively.

[0059] Next, the control determination unit compares the relative deviations of the input voltage, the first-stage voltage, and the second-stage voltage along the power supply direction. Since 0.03 is greater than 0.016, and 0.016 is greater than approximately 0.0121, the relative deviations of the input voltage, the first-stage voltage, and the second-stage voltage do not increase progressively along the power supply direction. Therefore, the control determination unit determines the comparison result of this control cycle as a progressively converging relationship and outputs a control signal to the first-stage switching DC-DC converter to continue the conversion, allowing the first-stage voltage regulation to continue. The first-stage switching DC-DC converter continues to generate the first-stage regulated output, and the second-stage low-dropout linear regulator continues to generate the second-stage regulated output from the first-stage regulated output.

[0060] In another control cycle, the voltage acquisition unit obtains the input voltage at the same sampling time. The voltage is 23.76V, and the first-stage voltage is obtained. The voltage is 5.25V, and the secondary voltage is obtained. The voltage is 3.30V. The nominal input voltage remains 24V, the primary nominal voltage remains 5V, and the secondary nominal voltage remains 3.3V. The relative deviation determination unit determines the relative deviation of the input voltage as follows: The calculated result is 0.01; the relative deviation of the first-level voltage is... The calculated result is 0.05; the relative deviation of the secondary voltage is... The calculation result is 0. Since the relative deviation of the first-stage voltage is greater than the relative deviation of the input voltage, and the relative deviations of the input voltage, the first-stage voltage, and the second-stage voltage do not increase progressively along the power supply direction, the control judgment unit determines the comparison result as a non-progressive convergence relationship and controls the first-stage switching DC-DC converter to stop switching, thus stopping the first-stage voltage regulation conversion.

[0061] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A power supply method for industrial control boards based on two-stage voltage regulation and multi-stage protection, used for a two-stage cascaded voltage-regulating power supply chain for industrial control boards, wherein the two-stage cascaded voltage-regulating power supply chain includes a power supply input, a first-stage voltage-regulating output, and a second-stage voltage-regulating output along the power supply direction, characterized in that, include: Use the output of the first-stage regulator as the input of the second-stage regulator; During the acquisition of input voltage, first-stage voltage, and second-stage voltage, the cascaded power supply connection between the power supply input, the first-stage regulated output, and the second-stage regulated output remains unchanged. Based on the nominal inlet voltage, the primary nominal voltage, and the secondary nominal voltage, the relative deviations of the inlet voltage, the primary voltage, and the secondary voltage are determined respectively. The relative deviations of the inlet voltage, the primary voltage, and the secondary voltage respectively characterize the degree of deviation of the inlet voltage from the nominal inlet voltage, the primary voltage from the primary nominal voltage, and the secondary voltage from the secondary nominal voltage. The relative deviations of the input voltage, the first-level voltage, and the second-level voltage are compared along the power supply direction. The comparison results in which the relative deviations of the input voltage, the first-level voltage, and the second-level voltage do not increase step by step along the power supply direction are determined as step-by-step convergence relationships, and other comparison results are determined as non-step-by-step convergence relationships. When the relationship is determined to be a stepwise convergence relationship, the first-stage voltage regulation transformation continues; when the relationship is determined to be a non-stepwise convergence relationship, the first-stage voltage regulation transformation stops.

2. The power supply method for industrial control boards based on two-stage voltage regulation and multi-stage protection according to claim 1, characterized in that, The first stage of voltage regulation and conversion is performed by a first-stage switching DC-DC converter.

3. The power supply method for industrial control boards based on two-stage voltage regulation and multi-stage protection according to claim 1, characterized in that, The second-stage regulated output is formed by the output of the second-stage low-dropout linear regulator, and the first-stage regulated output is fed into the second-stage low-dropout linear regulator.

4. The power supply method for industrial control boards based on two-stage voltage regulation and multi-stage protection according to claim 1, characterized in that, Before obtaining the input voltage, the DC power supplied from the industrial site is connected to the subsequent power supply path of the two-stage cascaded voltage regulator power supply chain via the reverse connection protection diode; When the input polarity is correct, the reverse protection diode is turned on; when the input polarity is reversed, the reverse protection diode is turned off and blocks the reverse current.

5. The power supply method for industrial control boards based on two-stage voltage regulation and multi-stage protection according to claim 4, characterized in that, A transient suppression diode is installed between the input node after reverse connection protection and ground. The input node after reverse connection protection is located on the output side of the reverse connection protection diode, and the transient suppression diode clamps the voltage when a transient overvoltage or surge occurs.

6. The power supply method for industrial control boards based on two-stage voltage regulation and multi-stage protection according to claim 2, characterized in that, An input filter network consisting of an inductor and an input filter capacitor is provided on the input side of the first-stage switching DC-DC converter, and the input filter network suppresses high-frequency interference entering the first-stage switching DC-DC converter.

7. The power supply method for industrial control boards based on two-stage voltage regulation and multi-stage protection according to claim 1, characterized in that, The input voltage is obtained from the sampling position corresponding to the power supply input, the first-stage voltage is obtained from the sampling position corresponding to the first-stage regulated output, and the second-stage voltage is obtained from the sampling position corresponding to the second-stage regulated output.

8. The power supply method for industrial control boards based on two-stage voltage regulation and multi-stage protection according to claim 1, characterized in that, The input voltage, first-level voltage, and second-level voltage are obtained at the same sampling time.

9. The power supply method for industrial control boards based on two-stage voltage regulation and multi-stage protection according to claim 1, characterized in that, Set a first-stage output filter capacitor at the output terminal corresponding to the first-stage regulated output, and set a second-stage output filter capacitor at the output terminal corresponding to the second-stage regulated output.

Images