POE double-circuit power supply current balance control method and circuit

Abstract

The invention relates to the technical field of POE power supply, in particular to a POE double-circuit power supply current balance control method and circuit. Comprising the following steps that real-time current detection is carried out on a load resistor in a two-way POE power supply circuit through a voltameter, voltage signals corresponding to branch currents are generated, the detection end of the voltameter is connected with the load resistor in series, and the voltameter is used for linearly converting the current signals into the voltage signals and providing real-time feedback data for differential amplification. According to the invention, a closed-loop control mechanism of real-time current detection-differential amplification feedback-active voltage regulation is constructed, so that the problem of unbalanced double-path POE power supply current is effectively solved. According to the technical scheme, through accurate signal conversion and proportion amplification, high-sensitivity sensing and real-time response to the two-way current difference are achieved, the risk of single-way overload is avoided, and the reliability and stability of a power supply system are improved.

Description

Technical Field

[0001] This invention relates to the field of PoE power supply technology, specifically to a PoE dual-channel power supply current balancing control method and circuit. Background Technology

[0002] With the rapid development of enterprise-level network equipment, high-power 10 Gigabit wireless access points (APs) and other terminals are placing higher demands on power supply systems. When single-port PoE (Power over Ethernet) power supply standards such as 802.3af / at cannot meet the power consumption requirements of the devices, dual-port PoE parallel power supply becomes a necessary choice. However, in existing dual-PoE power supply systems, due to differences in the output characteristics of each port and dynamic load changes, imbalances in the current supplied by the two power sources are prone to occur.

[0003] Traditional passive current sharing solutions rely on output impedance matching or simple feedback adjustment, which makes it difficult to achieve real-time dynamic balancing. This can lead to single-path overload, decreased system efficiency, or unstable equipment operation. Especially in complex enterprise network environments, differences in switch port compatibility further exacerbate the uncertainty of current distribution. There is an urgent need for a control mechanism that can actively sense current differences and make precise adjustments to solve the current balancing control problem when dual PoE power supplies are connected in parallel, ensuring the stable operation of high-power devices. Summary of the Invention

[0004] This disclosure proposes a POE dual-power supply current balancing control method and circuit, aiming to overcome at least one defect in the prior art.

[0005] To achieve the above objectives, the technical solution disclosed in this invention is as follows:

[0006] According to one aspect of this disclosure, a method for balancing current in dual-supply PoE power sources is provided, comprising the following steps:

[0007] The load resistor in the dual-path PoE power supply circuit is detected in real time by a power meter, and a voltage signal corresponding to the current of each branch is generated. The detection end of the power meter is connected in series with the load resistor to linearly convert the current signal into a voltage signal, providing real-time feedback data for differential amplification.

[0008] The two voltage signals are input into a differential amplifier for differential amplification to generate two feedback voltage signals. The differential amplifier uses a common voltage input and a preset reference voltage as a reference to amplify the difference between the two voltage signals to form a feedback voltage proportional to the current difference.

[0009] The two feedback voltage signals are input into the double POE control end, and the double POE output voltage is adjusted for the active balancing of the double power supply current. The feedback voltage signal is linked with the voltage adjustment mechanism of the POE control end. When one current is greater than the other, the corresponding POE output voltage is raised or lowered to form a voltage difference at the load end to force the current to be redistributed to the balanced state.

[0010] Further, the electric quantity meter includes a first electric quantity meter OU9 and a second electric quantity meter OU10. The detection end of the first electric quantity meter OU9 is connected in series between the load resistors OR104 and OR105 of the first POE power supply circuit, and the detection end of the second electric quantity meter OU10 is connected in series between the load resistors OR116 and OR117 of the second POE power supply circuit. The voltage signals generated by the currents flowing through the load resistors OR104, OR105, OR116 and OR117 are collected in real time, and the corresponding voltage signals are output through the output pins. The load resistors OR104, OR105, OR116 and OR117 are sampling resistors for converting current signals into voltage signals to meet the input requirements of the subsequent amplification circuit.

[0011] Further, the differential amplifier includes a first differential amplifier OU4 and a second differential amplifier OU5. The inverting input end of the first differential amplifier OU4 and the inverting input end of the second differential amplifier OU5 are connected to the same reference voltage, and the non-inverting input ends are connected to the voltage signals output by the corresponding electric quantity meters. The amplification factor of the differential amplifier is configured by peripheral resistors, and the two voltage signals are processed based on the difference amplification principle. The reference voltage is generated by a zener tube circuit to provide a unified comparison reference.

[0012] Further, the reference voltage is generated by a zener tube TLV431 circuit. The anode of the zener tube TLV431 is connected to ground, and the cathode outputs a stable reference voltage to the inverting input ends of the first differential amplifier OU4 and the second differential amplifier OU5. The zener tube TLV431 circuit includes a voltage dividing resistor and a filter capacitor to suppress power supply noise.

[0013] Further, when the first POE output current is greater than the second POE output current, the feedback voltage FB1 output by the first differential amplifier OU4 increases, and the feedback voltage FB2 output by the second differential amplifier OU5 decreases, and the POE control end adjusts the output voltage according to the feedback voltages FB1 and FB2: the POE control end of the POE with the greater current receives a feedback signal FB1 higher than the reference voltage, and then lowers the output voltage, and the POE control end of the POE with the smaller current receives a feedback signal FB2 lower than the reference voltage, and then raises the output voltage, and through the reverse adjustment of the output voltages of the two channels, current balance is achieved at the load end; the adjustment mechanism utilizes the characteristic that the two channels of POE are connected in parallel at the load end, and forces the current to be redistributed through the voltage difference.

[0014] According to another aspect of the present disclosure, a POE dual-channel power supply current balance control circuit is provided for implementing the POE dual-channel power supply current balance control method as described above, and the circuit comprises:

[0015] An electric quantity meter module comprises a first electric quantity meter OU9 and a second electric quantity meter OU10, the detection end of the first electric quantity meter OU9 is connected in series between the load resistors OR104 and OR105 of the first POE power supply circuit, and the output end is connected to the first voltage signal acquisition end; the detection end of the second electric quantity meter OU10 is connected in series between the load resistors OR116 and OR117 of the second POE power supply circuit, and the output end is connected to the second voltage signal acquisition end, for real-time detection of the dual-channel power supply current and conversion into a voltage signal;

[0016] A differential amplification module comprises a first differential amplifier OU4 and a second differential amplifier OU5, the non-inverting input end of the first differential amplifier OU4 is connected to the first voltage signal, the inverting input end is connected to the reference voltage, and the output end is connected to the first feedback voltage FB1; the non-inverting input end of the second differential amplifier OU5 is connected to the second voltage signal, the inverting input end is connected to the reference voltage, and the output end is connected to the second feedback voltage FB2, for differential amplification of the dual-channel voltage signals and generation of the feedback voltages FB1 and FB2;

[0017] A reference voltage module comprises a zener TLV431, the cathode of the zener TLV431 outputs a stable reference voltage to the inverting input ends of the first differential amplifier OU4 and the second differential amplifier OU5, the anode is connected to the ground, and peripheral resistors and capacitors are configured, for providing an accurate comparison reference;

[0018] A feedback adjustment module comprises dual-channel POE control ends, the first feedback voltage FB1 is connected to the voltage adjustment pin of the first POE control end, and the second feedback voltage FB2 is connected to the voltage adjustment pin of the second POE control end, for adjusting the POE output voltage according to the feedback voltages FB1 and FB2, to achieve current balance.

[0019] Further, the load resistors OR104, OR105, OR116, OR117 of the electric quantity meter module are sampling resistors, which are connected in series with the POE output end, and the voltage signals at the two ends thereof are input to the detection pins of the first electric quantity meter OU9 and the second electric quantity meter OU10, so as to convert the current change into a measurable voltage signal.

[0020] Further, the peripheral circuit of the differential amplification module comprises a matching resistor connected between the non-inverting input terminals, inverting input terminals and output terminals of the first differential amplifier OU4 and the second differential amplifier OU5, and the resistance ratio of the matching resistor determines the amplification multiple of the differential amplifier, so as to form linear differential amplification; the power supply end of the differential amplifier is connected to a stabilized power supply and is connected in parallel with a decoupling capacitor, so as to suppress the influence of the power supply ripple on the amplification accuracy.

[0021] Further, the voltage stabilizing tube TLV431 circuit of the reference voltage module comprises a pull-up resistor and a filter capacitor, one end of the pull-up resistor is connected to an input power supply, the other end is connected to the cathode of the voltage stabilizing tube TLV431, and the filter capacitor is connected in parallel between the cathode of the voltage stabilizing tube TLV431 and the ground, so as to filter out high-frequency noise in the input power supply, ensure the stability of the output reference voltage, and provide a reference potential for differential amplification.

[0022] Further, the POE control end of the feedback adjustment module is integrated in the POE power supply chip, the POE power supply chip supports adjusting the output voltage through external feedback voltages FB1 and FB2; current limiting resistors are arranged between the feedback voltages FB1 and FB2 and the voltage adjustment pins of the POE control end, so as to protect the input port of the control end and avoid overvoltage damage.

[0023] The present application has the following advantages:

[0024] The present application effectively solves the problem of unbalanced current of the dual-path POE power supply by constructing a closed-loop control mechanism of "real-time current detection-differential amplification feedback-active voltage adjustment". Specifically, the real-time current detection of the electric quantity meter on the load resistors of each branch converts the current signal into a voltage signal in a linear manner, the differential amplifier amplifies the voltage difference corresponding to the current difference with common voltage input design, forms a feedback voltage proportional to the current deviation, and then dynamically adjusts the output voltage through the POE control end, so as to force the load end current to be redistributed to an equilibrium state through the reverse adjustment of the dual-path output voltage.

[0025] Further, the technical scheme of the present application realizes high sensitivity perception and real-time response to the difference of double current through precise signal conversion and proportional amplification, avoids single path overload risk, and improves the reliability and stability of the power supply system. At the same time, the differential amplification architecture based on the generation of a unified reference voltage by a voltage stabilizing tube ensures the consistency of the comparison reference of the two signals, simplifies the circuit design complexity, reduces the system cost, and is especially suitable for enterprise-level POE power supply scenarios with high requirements for power consumption, stability and cost performance. Through active balancing control, the present application effectively improves the coordination efficiency of double POE parallel power supply, and provides reliable technical support for the stable operation of high-power network equipment.

[0026] The above description is only a summary of the technical scheme of the present application. In order to more clearly understand the technical means of the present application, and to implement the content of the specification, the following will be described in detail with the preferred embodiments of the present application and with the aid of the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 Flow chart of the POE double-path power supply current balancing control method in an embodiment of the present application;

[0028] Figure 2 Circuit diagram of the POE double-path power supply current balancing control circuit in an embodiment of the present application;

[0029] Figure 3 Circuit diagram of the power meter in an embodiment of the present application;

[0030] Figure 4 Circuit diagram of the differential amplifier in an embodiment of the present application;

[0031] Figure 5 Circuit diagram of the voltage stabilizing power supply in an embodiment of the present application;

[0032] Figure 6 Circuit diagram of the overall current balancing control in an embodiment of the present application;

[0033] Figure 7 Circuit diagram of the POE feedback control in an embodiment of the present application;

[0034] Figure 8 Schematic diagram of the differential amplifier in an embodiment of the present application;

[0035] Figure 9 Block diagram of the current balancing control circuit in an embodiment of the present application. DETAILED DESCRIPTION

[0036] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of them. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of the present application.

[0037] The term "comprising" and any variation thereof when used in the specification and claims of the present application shall be understood to encompass the elements or steps listed thereafter, including not only those elements or steps that are clearly listed, but also other elements or steps that are not clearly listed but are inherent to such processes, methods, compositions, or articles of manufacture. In addition, the use of "and / or", "and / or" in the specification and claims of the present application, means at least one of the connected objects, for example, A and / or B, means including A alone, B alone, and A and B both exist three cases.

[0038] In the embodiments of the present application, the words such as "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design presented as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or advantageous than other embodiments or design solutions. Rather, the use of "exemplary" or "for example" is intended to present relevant concepts in a concrete manner.

[0039] The present application provides the following preferred embodiments:

[0040] Embodiment one

[0041] In order to solve the problem of current imbalance caused by the difference in port output characteristics and the dynamic change of load in the dual-path POE power supply system, the present embodiment provides a POE dual-path power supply current balancing control method, which realizes active balancing control of dual-path power supply current through detailed design of power detection, signal amplification and feedback regulation mechanism. As shown in the figure, Figure 1 The flow of the POE dual-path power supply current balancing control method is as follows:

[0042] S100: Real-time current detection of the load resistor in the dual-path POE power supply circuit is performed by the power meter, and voltage signals corresponding to the branch currents are generated. The detection end of the power meter is connected in series with the load resistor, which is used to linearly convert the current signal into a voltage signal, and provide real-time feedback data for differential amplification.

[0043] S200: Two-way voltage signals are input into a differential amplifier for differential amplification processing, and two-way feedback voltage signals are generated. The differential amplifier adopts common voltage input, takes the preset reference voltage as the reference, amplifies the difference between the two-way voltage signals, and forms a feedback voltage proportional to the current difference.

[0044] S300: input the two feedback voltage signals into the double-channel POE control end respectively, adjust the double-channel POE output voltage, actively balance the double-channel power supply current, the feedback voltage signal is linked with the voltage regulation mechanism of the POE control end, when one channel current is greater than the other channel, the corresponding POE output voltage is raised or lowered, a voltage difference is formed at the load end to force the current to be redistributed to the balanced state.

[0045] In the double-channel POE power supply system, terminal devices such as enterprise-level gigabit APs need to be powered in parallel by two POE ports (POE1 and POE2). In this embodiment, the power meter selects MP8110 type chip, which has high precision current detection capability, and can collect branch current in real time and convert it into voltage signal. Specifically, the detection end of the first power meter OU9 is connected in series between the load resistors OR104 and OR105 of the first POE1 power supply circuit - it should be understood that the load resistors OR104 and OR105 here act as sampling resistors, and their resistance values are precisely selected to ensure that the voltage signal amplitude generated when the current flows meets the input requirements of the subsequent differential amplification circuit. Similarly, the detection end of the second power meter OU10 is connected in series between the load resistors OR116 and OR117 of the second POE2 power supply circuit. The two power meters respectively output voltage signals OUT1, OUT2 (corresponding to POE1) and another set of OUT1, OUT2 (corresponding to POE2) in real time, which are linearly proportional to the branch current, providing real-time feedback data for subsequent differential amplification processing.

[0046] Further, the differential amplification processing link adopts TPA6531 type differential amplifier, which is specifically configured as the first differential amplifier OU4 and the second differential amplifier OU5. The inverting input ends of the two differential amplifiers, i.e. the 4th pin IN-, are connected to the same reference voltage to form a common voltage input design. The reference voltage is generated by the TLV431 circuit - the anode of TLV431 is connected to ground, and the cathode is connected to the voltage stabilizing circuit composed of voltage dividing resistor and filter capacitor, which outputs a stable 2.5V reference voltage Vref. This voltage is connected to the inverting input ends of OU4 and OU5, which is used to provide a unified comparison reference. It should be noted that the resistance ratio of the voltage dividing resistor is calculated by circuit calculation to ensure that the stable output of 2.5V can be maintained when the power supply fluctuates, and the filter capacitor is used to suppress high-frequency noise and improve the purity of the reference voltage.

[0047] Further, in the differential amplification process, the non-inverting input terminal of the first differential amplifier OU4 is connected to the voltage signal output by the first coulomb meter OU9, and the non-inverting input terminal of the second differential amplifier OU5 is connected to the voltage signal output by the second coulomb meter OU10. The amplification factor of the differential amplifier is configured by the peripheral resistance network, and specifically follows the differential amplification principle: when the output currents of the two POEs are the same, the voltage signals output by the two coulomb meters are equal, at this time, the voltage difference between the non-inverting input terminal and the inverting input terminal of the differential amplifier is zero, and the feedback voltages FB1 and FB2 output by the differential amplifier both maintain the reference voltage value of 2.5V, and the POE control end does not perform voltage adjustment; when the output current of POE1 is greater than that of POE2, the voltage signal output by OU9 is higher than that output by OU10, the voltage of the non-inverting input terminal of OU4 is higher than the reference voltage of 2.5V of the inverting input terminal, and after amplification, the feedback voltage FB1 output is increased, and at the same time, the voltage of the non-inverting input terminal of OU5 is lower than that of the inverting input terminal, and after amplification, the feedback voltage FB2 output is decreased.

[0048] Further, the feedback voltage signal is linked with the voltage adjustment mechanism of the POE control end, and the specific adjustment process is as follows: after the POE1 control end receives the feedback signal FB1 higher than 2.5V, the internal voltage adjustment module thereof reduces the output voltage Vout_POE1 according to the feedback signal; after the POE2 control end receives the feedback signal FB2 lower than 2.5V, the output voltage Vout_POE2 is increased. Since the two POEs are connected in parallel at the load end, when Vout_POE1 is reduced and Vout_POE2 is increased, a voltage difference is formed between the two outputs, forcing the current to be redistributed from the POE2 branch with higher voltage to the POE1 branch with lower voltage, until the two currents reach a balanced state. Conversely, if the output current of POE2 is greater than that of POE1, the feedback voltage FB2 is increased and FB1 is decreased, the output voltage of the POE2 control end is reduced, and the output voltage of the POE1 control end is increased, so as to realize current balance through reverse adjustment.

[0049] It should be understood that the common voltage input design of the differential amplifier ensures the consistency of the two signal comparison reference values, avoiding detection errors caused by reference voltage drift. At the same time, the MP8110 chip used by the coulomb meter has high bandwidth characteristics, which can respond to the dynamic changes of the current in real time, ensuring the timeliness of feedback adjustment. The selection of the load resistors OR104, OR105, OR116 and OR117 needs to meet the power dissipation requirement to avoid affecting the detection accuracy due to additional temperature rise in the sampling process, and the resistance value is usually in the order of milliohms to reduce the pressure drop on the main circuit.

[0050] In the voltage regulator TLV431 circuit, the precision level of the voltage dividing resistor needs to match the system's requirement for reference voltage stability. Usually, a precision resistor with an error of no more than 1% is selected, and a ceramic capacitor with good high-frequency characteristics is selected for the filter capacitor. The capacity is optimized according to the noise frequency characteristics of the circuit to effectively filter out the power supply ripple. The design of the differential amplifier peripheral resistor network needs to consider both the amplification factor and the noise suppression. By reasonably selecting the resistance value, the signal amplification effect is guaranteed while avoiding the introduction of additional thermal noise.

[0051] In the circuit architecture of the present embodiment, the power meter, differential amplifier, and voltage regulator circuit form a closed-loop control link: the power meter detects the current in real time and converts it to a voltage signal, the differential amplifier amplifies the signal proportionally and generates a feedback voltage, and the voltage regulator circuit provides a stable reference. The three work together to dynamically adjust the dual-path POE output voltage. This control method does not rely on complex digital signal processing, but only through the precise design of analog circuits can achieve current balancing. It has the advantages of simple control logic, fast response speed, and low cost, and is especially suitable for enterprise-level POE power supply scenarios that require high reliability and cost-effectiveness.

[0052] Further, for different models of POE control terminals, the feedback voltage signal can be adapted according to their internal adjustment mechanism - for example, if the feedback interface of the POE control terminal is voltage type input, then directly connect FB1 and FB2 signals; if it is current type input, then an I / V conversion module needs to be added in the feedback circuit. However, regardless of the interface form, the core function of the feedback signal is to indicate the current difference through voltage change, driving the control terminal to adjust the output voltage, thereby achieving current balancing at the load end.

[0053] Further, in actual application, the effectiveness of the control method of the present embodiment is verified by the following process: when there is a difference in the initial output current of the dual-path POE, the power meter detects the current difference and outputs the corresponding voltage signal difference, which generates asymmetric feedback voltages FB1 and FB2 after differential amplification. The POE control terminal adjusts the output voltage according to the feedback signal until the feedback voltage returns to the reference value when the two currents are equal, and the system enters a stable and balanced state. The entire adjustment process is completed within milliseconds, which can effectively deal with dynamic scenarios such as load mutation and ensure the stability of the power supply system.

[0054] It should be noted that the model selection of each component in the embodiment, such as MP8110, TPA6531 and TLV431, is based on existing mature devices, and the electrical parameters meet the circuit design requirements, and have good market compatibility and stable supply. The parameter configuration of passive devices such as load resistance and voltage dividing resistance needs to be calculated according to the voltage and current range of the specific application scene. For example, when the POE port output voltage is 48V, the resistance value of the sampling resistance needs to ensure that the input voltage of the power meter does not exceed its rated range, while considering the detection sensitivity.

[0055] The embodiment constructs a complete dual-path POE current equalization control scheme through specific design of each link of power detection, signal amplification and feedback regulation. The scheme uses the real-time signal processing capability of the analog circuit to realize high-sensitivity perception and precise feedback control of the current difference, avoids the risk of single-path overload, improves the collaborative efficiency of the power supply system, and provides reliable technical support for the stable operation of high-power network equipment. Through standardized device selection and modularized circuit design, the scheme has good engineering implementation and cost control capability, and is suitable for various scenes requiring dual-path POE parallel power supply.

[0056] Embodiment two

[0057] To solve the problem of current imbalance caused by the difference in port output characteristics in the dual-path POE power supply system, the embodiment provides a specific POE dual-path power supply current equalization control circuit, which realizes the hardware landing of the control method through the circuit architecture design of the power detection, signal amplification, reference voltage and feedback regulation modules. The circuit connection relationship and working principle of each functional module are described in detail in combination with the drawings.

[0058] In combination with Figure 2 , Figure 3 , Figure 6 and Figure 9 , the circuit implementation of the power meter module is as follows:

[0059] The first power meter OU9 and the second power meter OU10 configured in the circuit both use MP8110 type chips, and their detection ends are connected in series in the load resistance network of the dual-path POE power supply circuit. Specifically, the first path POE1 output end is connected to the load in sequence through load resistances OR104 and OR105, and the detection pins of OU9 are connected in parallel across OR104 and OR105, respectively, to collect the voltage difference generated by the current flowing through the resistances in real time. It should be noted that OR104 and OR105, as sampling resistances, have a resistance value of 0.1Ω high-precision alloy resistance, which ensures that the voltage signal generated by the rated current, such as 3.5A, is about 350mV, meeting the input dynamic range of MP8110. Similarly, OR116 and OR117 of the second path POE2 output end are connected to the detection end of OU10 in the same way.

[0060] Furthermore, such as Figure 3 As shown in the pin configuration, the MP8110's outputs OUT1 and OUT2 linearly convert the detected voltage signal, outputting voltage signals V1 and V2 proportional to the branch current; for example, 1A of current corresponds to 0.5V output. The circuit design of this module requires careful attention to the tight coupling between the detection terminals and the sampling resistor to avoid noise interference introduced by long traces. Simultaneously, a decoupling network consisting of a 10μF electrolytic capacitor and a 100nF ceramic capacitor should be connected in parallel at the chip's power supply terminal to ensure power supply stability.

[0061] Combination Figure 2 , Figure 4 , Figure 6 , Figure 8 and Figure 9 As shown, the signal processing mechanism of the differential amplifier module is as follows:

[0062] The differential amplifier module consists of a first differential amplifier OU4 and a second differential amplifier OU5. Their non-inverting inputs are connected to the V1 and V2 signals output from the fuel gauge, respectively, while their inverting inputs are connected to a common reference voltage Vref (2.5V). Figure 4 As shown, the non-inverting input of OU4, pin 3, is connected to OUT1 of OU9 through a 10kΩ matching resistor. The inverting input, pin 4, is directly connected to Vref. The output, pin 1, forms a closed loop with the inverting input through a 20kΩ feedback resistor. This resistor ratio determines the amplification factor to be 2. The actual amplification factor needs to be calculated based on the specific resistor network.

[0063] Combination Figure 8 The common voltage input structure and the shared inverting input of the two differential amplifiers ensure the consistency of the comparison reference and avoid detection errors caused by reference drift. In the external circuitry, a 5V regulated power supply is connected to pin 8, with a 100nF decoupling capacitor in parallel to suppress high-frequency ripple. The connection lines between the outputs FB1 and FB2 and the subsequent feedback adjustment module use differential routing to reduce the impact of electromagnetic interference on the signal. When the dual currents are balanced, V1 = V2, and both OU4 and OU5 outputs are 2.5V. When the POE1 current is greater than POE2, V1 > V2, the OU4 output FB1 rises to 3.0V, and the OU5 output FB2 falls to 2.0V, forming a feedback signal proportional to the current difference.

[0064] Combination Figure 2 , Figure 5 As shown, the reference voltage module's reference generation circuit is as follows:

[0065] The reference voltage module core device is TLV431, the anode of which is connected to ground, and the cathode is connected to the 12V input power supply through a 10kΩ pull-up resistor, outputting a stable 2.5V reference voltage. A 10μF filter capacitor and a 100nF ceramic capacitor are connected in parallel between the cathode of TLV431 and ground, the former filters out low-frequency ripple, and the latter suppresses high-frequency noise, ensuring that the voltage fluctuation of Vref is less than ±1mV. The voltage dividing resistor network is used to divide the input power supply to the working range of TLV431, and the accuracy is selected to be 1% error level to ensure the long-term stability of the reference voltage.

[0066] Further, the circuit layout of the reference voltage module needs to pay attention to the heat dissipation of TLV431 to avoid reference drift caused by temperature rise, and the power selection of the pull-up resistor needs to meet the power consumption requirements, such as 14.4mW power consumption of 10kΩ resistor under 12V power supply, which can be selected as 1 / 8W specification. The reference voltage is connected to the inverting input terminals of OU4 and OU5 through short-distance wiring, reducing the influence of line impedance on reference consistency.

[0067] In combination with Figure 2 , Figure 7 , the voltage control logic of the feedback regulation module is as follows:

[0068] The core of the feedback regulation module is the control end integrated in the POE power supply chip, as shown in Figure 7 , the first feedback voltage FB1 is connected to the voltage regulation pin of POE1 control chip through a 1kΩ current limiting resistor, and the second FB2 is connected to POE2 control chip in the same way. The purpose of setting the current limiting resistor is to protect the input port of the control end and avoid overvoltage damage when the differential amplifier abnormally outputs, such as limiting the maximum voltage of FB1 to within 5V.

[0069] When FB1>2.5V, the internal feedback loop of POE1 control end triggers the step-down mechanism, reducing the output voltage Vout_POE1 by adjusting the PWM duty cycle; when FB2<2.5V, the POE2 control end triggers the step-up mechanism, increasing Vout_POE2. Since the two-way POE output is parallel at the load end, the voltage difference is adjusted in the opposite direction, i.e. Vout_POE1↓, Vout_POE2↑, forcing the current to redistribute from the high-voltage branch to the low-voltage branch, until FB1=FB2=2.5V, reaching the equilibrium state. The feedback response time of the control chip needs to match the bandwidth of the differential amplification module, such as μs level response, to ensure the timeliness of the regulation under dynamic load.

[0070] Further, the signal transmission between the modules of the embodiment follows the principle of high-frequency signal short-distance wiring, especially the voltage signal output by the electric quantity meter and the feedback signal of the differential amplifier, which adopts inner layer shielding wiring to reduce crosstalk. The sampling resistors OR104-OR105 and OR116-OR117 are connected to the detection end of the electric quantity meter in a four-terminal Kelvin connection mode, eliminating the influence of line resistance on detection accuracy. The power input port is configured with an EMI filter circuit to suppress the influence of external interference on the reference voltage and the amplification circuit.

[0071] It should be understood that the matching resistor of the differential amplifier needs to use a precision resistor with consistent temperature coefficient to ensure the stability of the amplification factor when the temperature changes; the power margin of the sampling resistor of the electric quantity meter module needs to be reserved by more than 50%, such as using a 1W specification when the rated power consumption is 0.5W, to avoid resistance drift caused by heating during long-term operation.

[0072] The benefits of the embodiment are that the active equalization control of the dual-path POE current is realized through the modular circuit design, and each functional module has clear division of labor and mutual coordination: the electric quantity meter module completes the current-voltage signal conversion, the differential amplification module realizes proportional amplification of the difference signal, the reference voltage module provides a stable reference, and the feedback adjustment module executes the voltage adjustment strategy. The circuit architecture does not depend on complex digital control, and real-time current sharing can be realized only through precise design of the analog circuit, which is suitable for the dual-port POE power supply scene of enterprise-level AP and other high-power devices, effectively improving the reliability and efficiency of the power supply system. The selection of each device in the circuit is based on mature commercial solutions, with good compatibility and cost advantage, providing a feasible path for engineering implementation.

[0073] Although the present application has been described above with reference to the preferred embodiments, it should be understood that the present application is not limited to the above-described embodiments, but various modifications and changes can be made by those skilled in the art without departing from the spirit of the present application, and such modifications and changes should fall within the scope of the appended claims and their equivalents.

Claims

1. A POE power over Ethernet current equalization control method, characterized in that, The method comprises the following steps: Real-time current detection of the load resistor in the dual-path POE power supply circuit is performed by using an ammeter, and a voltage signal corresponding to the current of each branch is generated, the detection end of the ammeter is connected in series with the load resistor, and the ammeter is used to linearly convert the current signal into a voltage signal and provide real-time feedback data for differential amplification; The two voltage signals are input into a differential amplifier for differential amplification processing, and two feedback voltage signals are generated, the differential amplifier adopts common voltage input, takes a preset reference voltage as a reference, amplifies the difference between the two voltage signals, and forms a feedback voltage proportional to the current difference; The two feedback voltage signals are input into the control end of the dual-path POE, the output voltage of the dual-path POE is adjusted, and the active balancing of the dual-path power supply current is performed, the feedback voltage signal is linked with the voltage adjustment mechanism of the POE control end, when the current of one path is greater than that of the other path, the corresponding POE output voltage is increased or decreased to form a voltage difference at the load end and force the current to be redistributed to the balanced state.

2. The POE power over Ethernet current equalization control method of claim 1, wherein, The ammeter comprises a first ammeter OU9 and a second ammeter OU10, the detection end of the first ammeter OU9 is connected in series between the load resistors OR104 and OR105 of the first-path POE power supply circuit, the detection end of the second ammeter OU10 is connected in series between the load resistors OR116 and OR117 of the second-path POE power supply circuit, the voltage signals generated by the current flowing through the load resistors OR104, OR105, OR116 and OR117 of each branch are collected in real time, and the corresponding voltage signals are output through the output pins, the load resistors OR104, OR105, OR116 and OR117 are sampling resistors, which are used to convert the current signal into a voltage signal to meet the input requirements of the subsequent amplification circuit.

3. The POE power over Ethernet current equalization control method of claim 1, wherein, The differential amplifier comprises a first differential amplifier OU4 and a second differential amplifier OU5, the inverting input end of the first differential amplifier OU4 and the inverting input end of the second differential amplifier OU5 are connected to the same reference voltage, and the non-inverting input ends are connected to the voltage signals output by the corresponding ammeters; the amplification factor of the differential amplifier is configured by peripheral resistors, and the two voltage signals are processed based on the difference amplification principle, wherein the reference voltage is generated by a zener tube circuit and is used to provide a unified comparison reference.

4. The POE power over 2-wire balancing control method of claim 3, wherein, The reference voltage is generated by a zener tube TLV431 circuit, the anode of the zener tube TLV431 is connected to ground, and the cathode outputs a stable reference voltage to the inverting input ends of the first differential amplifier OU4 and the second differential amplifier OU5; the zener tube TLV431 circuit comprises a voltage dividing resistor and a filtering capacitor, and is used to suppress power supply noise.

5. The POE power over Ethernet current equalization control method of claim 1, wherein, When the first POE output current is greater than the second POE output current, the feedback voltage FB1 output by the first differential amplifier OU4 is increased, the feedback voltage FB2 output by the second differential amplifier OU5 is decreased, and the POE control end adjusts the output voltage according to the feedback voltages FB1 and FB2: the POE control end of the POE with the greater current receives the feedback signal FB1 higher than the reference voltage, and the output voltage is decreased, the POE control end of the POE with the smaller current receives the feedback signal FB2 lower than the reference voltage, and the output voltage is increased, and the current balance is realized at the load end through the reverse adjustment of the output voltages of the two paths.

6. A POE power over Ethernet current balance control circuit for implementing the POE power over Ethernet current balance control method according to any one of claims 1 to 5, characterized in that, The circuit comprises: The electric quantity meter module comprises a first electric quantity meter OU9 and a second electric quantity meter OU10, the detection end of the first electric quantity meter OU9 is connected in series between the load resistors OR104 and OR105 of the first POE power supply circuit, and the output end is connected to the first voltage signal acquisition end; the detection end of the second electric quantity meter OU10 is connected in series between the load resistors OR116 and OR117 of the second POE power supply circuit, and the output end is connected to the second voltage signal acquisition end, for detecting the power supply currents of the two paths in real time and converting them into voltage signals; The differential amplification module comprises a first differential amplifier OU4 and a second differential amplifier OU5, the non-inverting input end of the first differential amplifier OU4 is connected to the first voltage signal, the inverting input end is connected to the reference voltage, and the output end is connected to the first feedback voltage FB1; the non-inverting input end of the second differential amplifier OU5 is connected to the second voltage signal, the inverting input end is connected to the reference voltage, and the output end is connected to the second feedback voltage FB2, for differentially amplifying the voltage signals of the two paths and generating the feedback voltages FB1 and FB2; The reference voltage module comprises a voltage stabilizing tube TLV431, the cathode of the voltage stabilizing tube TLV431 outputs a stable reference voltage to the inverting input ends of the first differential amplifier OU4 and the second differential amplifier OU5, the anode is grounded, and the periphery is configured with a voltage dividing resistor and a filter capacitor, for providing an accurate comparison reference; The feedback adjustment module comprises two POE control ends, the first feedback voltage FB1 is connected to the voltage adjustment pin of the first POE control end, the second feedback voltage FB2 is connected to the voltage adjustment pin of the second POE control end, for adjusting the POE output voltage according to the feedback voltages FB1 and FB2, and realizing the current balance.

7. The POE power over 2-wire supply current equalization control circuit of claim 6, wherein, The load resistors OR104, OR105, OR116 and OR117 of the electric quantity meter module are sampling resistors, which are connected in series with the POE output end, the voltage signals at the two ends of the sampling resistors are input to the detection pins of the first electric quantity meter OU9 and the second electric quantity meter OU10, for converting the current change into a measurable voltage signal.

8. The POE power sourcing equipment current balancing control circuit of claim 6, wherein, The peripheral circuit of the differential amplification module comprises a matching resistor connected between the non-inverting input terminals, inverting input terminals and output terminals of the first differential amplifier OU4 and the second differential amplifier OU5, and the resistance ratio of the matching resistor determines the amplification multiple of the differential amplifier, thereby forming linear differential amplification; and the power supply end of the differential amplifier is connected to a stabilized power supply and is connected in parallel with a decoupling capacitor, thereby suppressing the influence of power supply ripple on amplification accuracy.

9. The POE power over 2-wire supply current equalization control circuit of claim 6, wherein, The voltage stabilizing tube TLV431 circuit of the reference voltage module comprises a pull-up resistor and a filter capacitor, one end of the pull-up resistor is connected to an input power supply, the other end is connected to the cathode of the voltage stabilizing tube TLV431, and the filter capacitor is connected in parallel between the cathode of the voltage stabilizing tube TLV431 and the ground, thereby filtering high-frequency noise in the input power supply and ensuring the stability of the output reference voltage, thereby providing a reference potential for differential amplification.

10. The POE power over 2-wire supply current equalization control circuit of claim 6, wherein, The POE control end of the feedback adjustment module is integrated in a POE power supply chip, the POE power supply chip supports adjusting the output voltage through external feedback voltages FB1 and FB2; and a current-limiting resistor is arranged between the feedback voltages FB1 and FB2 and the voltage adjustment pin of the POE control end, thereby protecting the input port of the control end and avoiding overvoltage damage.

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