Solar energy storage control circuit with input side energy detection function

Abstract

The utility model relates to circuit technical field, concretely is a kind of solar energy storage control circuit with input side energy detection function, to solve the battery energy reverse backflow, system efficiency decline and loop instability problem caused by input side energy fluctuation in unstable energy supply scene such as solar energy, wind energy.The control circuit is applied to connect energy input end and energy storage medium, comprising: synchronous step-down circuit, for adjusting the charging voltage and current from energy input end to energy storage medium;Input current detection module is coupled between energy input end and synchronous step-down circuit, for detecting input current by detecting resistance Rsen, and combining the current flowing through resistance R2 generated by oscillation signal, generate detection signal proportional to input current size;Reference voltage generating circuit generates reference voltage;Comparison and control module is used for comparing detection signal and reference voltage, and generates control signal according to comparison result, to turn on or turn off the charging path of synchronous step-down circuit.

Description

Technical Field

[0001] This utility model relates to the field of circuits and provides a solar energy storage control circuit with input-side energy detection function. Background Technology

[0002] Traditional energy storage and charging management systems, especially in consumer electronics, are typically designed with a stable and continuous power input. However, when applications shift to outdoor renewable energy sources (such as solar and wind power), the characteristics of the input power source change fundamentally. The energy supply becomes intermittent, highly volatile, and unpredictable, fluctuating drastically due to natural factors such as sunlight intensity, cloud cover, and wind speed.

[0003] Under conditions of low energy supply, such as on cloudy days or when solar panels are partially shaded, the input voltage may be lower than the voltage of the energy storage battery. In this situation, without effective protection measures, energy from the battery side may flow back to the power supply side or be discharged to ground, creating a "current backflow" phenomenon. This backflow not only wastes valuable energy and reduces the overall efficiency of the system, but more seriously, it may cause over-discharge damage to the battery, shortening its lifespan and even posing safety risks.

[0004] To address this issue, the most common solution in the prior art is to connect an anti-reverse-current diode (typically a Schottky diode) in series in the charging path. However, this solution has the following inherent drawbacks:

[0005] Efficiency loss: Diodes have a forward voltage drop (typically 0.3V to 0.7V). During high-current charging, this voltage drop leads to significant power loss and heat generation, directly reducing the system's charging efficiency.

[0006] Cost and complexity: To cope with the heat generated by high current, diodes often need to be equipped with heat sinks, which not only increases the bill of materials (BOM) but also increases the size and design complexity of the product.

[0007] Performance bottleneck: Schottky diodes experience a significant increase in leakage current at high temperatures, which further exacerbates energy loss. Utility Model Content

[0008] The purpose of this invention is to provide a hardware-level circuit structure to address the problems of reverse battery energy flow, system efficiency degradation, and loop instability caused by input-side energy fluctuations in unstable energy supply scenarios such as solar and wind power. Specifically:

[0009] 1. Eliminate the risk of energy backflow: Through the real-time pulse energy detection mechanism on the input side (Detector terminal + Rsen resistor), the power supply current intensity is dynamically monitored. When the detected value is lower than the adjustable threshold (VDET < VREF), the charging loop is automatically cut off to prevent battery energy from leaking through the power supply side or GND.

[0010] 2. Overcoming the limitations of traditional solutions: Replacing the anti-reverse-current diode solution, solving its drawbacks such as high cost, severe heat generation, and system efficiency degradation;

[0011] 3. Improve system adaptability: through adjustable oscillation frequency ( Figure 3 With flexible configuration of Rsen resistance, it is compatible with monitoring needs at different time interval levels and adapts to different light / wind fluctuation scenarios, achieving the optimal balance between energy consumption and monitoring accuracy.

[0012] To achieve the above objectives, the present invention employs the following technical means:

[0013] This utility model provides an energy storage control circuit with input-side energy detection function, applied to connecting the energy input terminal and the energy storage medium, including:

[0014] A synchronous buck circuit is used to regulate the charging voltage and current from the energy input terminal to the energy storage medium;

[0015] An input current detection module is coupled between the energy input terminal and the synchronous buck circuit to generate a detection signal that is proportional to the magnitude of the input current flowing through the energy input terminal.

[0016] A reference voltage generation circuit is used to produce a stable, accurate, temperature-independent reference voltage.

[0017] The comparison and control module is used to compare the detection signal with the reference voltage and generate a control signal based on the comparison result to turn on or off the charging path of the synchronous buck circuit.

[0018] The input current detection module is configured to periodically detect current in a pulse manner.

[0019] In the above scheme, the input current detection module includes:

[0020] A detection resistor Rsen is connected in series in the circuit of the energy input terminal to convert the input current into a detection voltage as the detection signal;

[0021] An oscillation signal generation circuit is used to generate a pulse signal with a preset frequency;

[0022] The switching element N1, controlled by the pulse signal, is used to periodically connect the probe voltage to the comparison and control module.

[0023] In the above scheme, the comparison and control module includes:

[0024] The comparison unit includes a comparator, a reference voltage source that generates a temperature-independent reference voltage VREF, and the comparator is used to compare the sampling voltage VDET of the detection signal output by the input current detection module with the reference voltage VREF.

[0025] The control unit controls the charging operation based on the output of the comparison unit: when VDET > VREF, the charging loop is maintained to operate normally; when VDET < VREF, the charging loop is closed to prevent battery energy from flowing back to the input side or ground.

[0026] In the above scheme, the control unit is integrated in the synchronous buck topology and includes NMOS and PMOS switching elements controlled by drive signals DRVP and DRVN for managing the charging operation of the energy storage medium at the output terminal.

[0027] In the above scheme, the switching element N1 is a MOS switch. When it is turned on under the control of the oscillation signal, it forms a current path from the detection terminal Detector to the ground terminal GND, and generates the sampling voltage VDET on the resistor R2.

[0028] Because this utility model adopts the above-mentioned technical means, it has the following beneficial effects:

[0029] 1. This utility model periodically detects the input current in a pulse manner through an input current detection module (including a detection resistor Rsen, an oscillation signal generation circuit, and a switching element N1), and compares the detected signal with a reference voltage in conjunction with a comparison and control module. This solves the technical problem of reverse energy flow of the battery under weak power supply conditions, and achieves the effects of preventing energy waste, protecting battery life, and improving system safety.

[0030] In scenarios with unstable power supply, such as solar or wind power, the input energy may drop sharply due to environmental factors (such as cloud cover), causing the input voltage to fall below the battery voltage. Traditional solutions rely on anti-backflow diodes, but cannot dynamically respond to energy fluctuations. This invention uses a pulse-type detection mechanism to monitor the input current in real time (converting it into a detection signal VDET). When VDET falls below the reference voltage VREF (indicating insufficient input current), the comparison and control module immediately shuts off the charging path of the synchronous buck circuit, cutting off the energy transmission channel. This prevents battery energy from flowing back through the input side or ground, eliminating energy waste and the risk of battery over-discharge. Furthermore, this mechanism is only activated during the detection cycle (when the oscillation signal controls N1 to conduct), remaining off during non-detection periods to ensure timely response without continuous energy consumption.

[0031] 2. This utility model solves the technical problems of high energy loss and low system efficiency in traditional continuous monitoring schemes by using a pulse detection mechanism (an oscillation signal generation circuit generates an adjustable frequency pulse signal to control the periodic conduction of the switching element N1), thereby achieving the effect of reducing monitoring energy consumption and optimizing the overall system efficiency.

[0032] Traditional reverse-current protection diode solutions suffer from fixed power loss due to forward voltage drop (especially with increased leakage current at high temperatures), leading to decreased system efficiency and requiring additional heat dissipation design. This invention replaces the diode with a pulse probe, briefly activating the probe circuit (N1 conducts to form a current path) only when triggered by an oscillation signal, and then shutting off after generating VDET. This intermittent operating mode significantly reduces static current consumption during the probe process. Furthermore, the oscillation frequency can be flexibly configured using external components (such as resistors and capacitors) to adapt to different power supply fluctuation scenarios. Therefore, while ensuring timely monitoring, energy loss is minimized, avoiding the efficiency degradation problem of traditional solutions.

[0033] 3. Based on the hardware structure provided by this utility model, derivative applications can be developed. A temperature-stable reference voltage VREF is generated through a reference voltage generation circuit. Combined with the dynamic control logic of the comparison and control module (maintaining charging when VDET > VREF and shutting off the charging path when VDET < VREF), the technical problem of loop instability and malfunction caused by input energy fluctuations is solved, thereby enhancing the robustness and adaptability of the system.

[0034] In outdoor environments, temperature changes can easily cause threshold drift, leading to misjudgments of the power supply status in traditional solutions (e.g., increased diode leakage current at high temperatures may falsely trigger reverse current). This invention's reference voltage circuit utilizes the mutual compensation of the positive and negative temperature coefficients of transistors Q1 and Q2 (adjusted via resistor R1) to generate a temperature-independent VREF. This ensures the stability of the comparison threshold and avoids false turn-off or false charging caused by temperature fluctuations. Simultaneously, the comparison and control module dynamically manages the charging path of the synchronous buck circuit (e.g., controlling switching elements with DRVP / DRVN signals) based on the real-time comparison results of VDET and VREF. When the input energy fluctuates drastically, this mechanism responds quickly (e.g., decision-making within the pulse detection cycle) to prevent loop instability due to insufficient energy. Furthermore, the adjustable Rsen resistance value adapts to different application scenarios, achieving an optimal balance between energy consumption and accuracy.

[0035] 4. This utility model solves the technical problems of high cost and complex structure of traditional solutions by integrating the control unit into the synchronous buck topology (NMOS and PMOS switching elements are driven by DRVP / DRVN) and combining the overall architecture of input-side energy detection, thus achieving the effect of simplifying system design and reducing implementation cost.

[0036] Traditional reverse-current protection diode solutions require additional heat dissipation components (such as heat sinks) to handle high current heat generation, increasing material costs and size. This invention integrates the control logic into a synchronous buck circuit (e.g., switching elements are directly managed by the drive signal), eliminating the need for discrete diodes. The input current sensing module requires only basic components (Rsen, R2, N1, and an oscillation circuit), resulting in a simple structure. By replacing the diode function with pulse sensing, the heat dissipation requirement is eliminated, reducing BOM costs and design complexity. Attached Figure Description

[0037] Figure 1 Topology schematic diagram;

[0038] Figure 2 Schematic diagram of real-time detection principle on the energy input side;

[0039] Figure 3 Oscillator circuit;

[0040] Figure 4 Reference voltage source generation circuit. Detailed Implementation

[0041] The embodiments of this utility model will be described in detail below. Although this utility model will be described and illustrated in conjunction with some specific embodiments, it should be noted that this utility model is not limited to these embodiments. On the contrary, any modifications or equivalent substitutions made to this utility model should be covered within the scope of the claims of this utility model.

[0042] Furthermore, to better illustrate this invention, numerous specific details are provided in the following detailed embodiments. Those skilled in the art will understand that this invention can be implemented without these specific details.

[0043] This invention introduces a solar energy storage control circuit with input-side energy detection function. It can control whether to charge the output energy storage medium (battery) based on the input energy level. This circuit is compatible with input-side energy sources converted from solar and wind power.

[0044] The features of this utility model are:

[0045] (1) A charging management system specifically designed for outdoor solar, wind and other energy sources can adaptively adjust the charging current and set the minimum energy threshold on the power supply side to achieve the expected function of shutting down the loop when the power supply is weak, thereby preventing current backflow.

[0046] (2) It can prevent the system from being inefficient or even unstable under different lighting conditions.

[0047] To facilitate a better understanding of the technical solution of this utility model by those skilled in the art, the following further explanation is provided:

[0048] Figure 1 As can be seen, the overall circuit is a synchronous buck topology, and the output stage consists of an NMOS and a PMOS, driven by DRVP and DRVN respectively.

[0049] The left input terminal is for energy input from solar, wind, generator, or standard AC voltage (220V). Rsen, highlighted in red, is the sensing resistor, and its value can be selected according to different application scenarios. VIN passes through the Rsen resistor and then enters the internal Detector terminal of the chip for pulsed real-time detection of the input current. This mechanism will be further described below.

[0050] Figure 2 This is a real-time detection circuit diagram on the energy input side.

[0051] The oscillation signal generation circuit module generates a desired oscillation frequency. During half a cycle, MOS switch N1 is turned on, and the current flowing from the detector terminal forms a path to GND. The voltage across R2 rises, generating voltage V. DET The reference voltage V generated by the reference comparison voltage module REF Compare them.

[0052] (1) If V DET >V REFThis indicates that the current injected into the chip by VIN can reach a certain set current value, which means that the energy supply on the input side can meet the usage requirements and the whole system is working normally.

[0053] (2) If V DET <V REF This indicates that the current injected into the chip by VIN cannot reach a certain set current value. It can be assumed that the energy supply on the input side cannot meet the usage requirements, so the loop needs to be closed to prevent the battery energy from flowing back.

[0054] Current market products cannot meet the requirements for real-time detection and control. The existing solution is to add anti-backflow diodes to address battery energy backflow, but this significantly increases the overall cost, makes the system more complex, and causes severe heat generation, thus reducing system efficiency. Therefore, its limitations are very obvious. The circuit method described above can perfectly solve this problem.

[0055] Figure 4 This is a reference voltage source generation circuit. This module generates a precise and constant reference voltage VR, which serves as the comparison reference for the comparator.

[0056] The principle is:

[0057] Because transistors Q1 and Q2 have a 1:n ratio, they will generate a voltage difference: δVbe. Dividing this voltage by R2 will produce equal currents flowing through Q1 and Q2. Since Vbe has a negative temperature coefficient and δVbe has a positive temperature coefficient, by adjusting the resistance of R1, a temperature-independent (i.e., zero temperature coefficient) reference voltage V can be obtained. REF .

[0058] The formula for calculating the Vref voltage is given below:

[0059] Vref=Vbe+(R1 / R2)*δVbe

[0060] Where Vbe is the negative temperature coefficient and δVbe is the positive temperature coefficient, theoretically, by adjusting the ratio of (R1 / R2), a reference voltage Vref with zero temperature coefficient can be obtained.

[0061] Figure 3 It is an oscillation signal generation circuit, and OSC is the output oscillation signal.

[0062] This circuit allows you to obtain the desired oscillation frequency by selecting different resistor and capacitor values. If a low-frequency oscillation signal is required, you can also obtain millisecond-level and second-level oscillation signals by frequency division of the OSC signal, thus meeting different application requirements.

[0063] Example 1

[0064] This utility model provides an energy storage control circuit with input-side energy detection function, applied to connecting the energy input terminal and the energy storage medium, characterized in that it includes:

[0065] A synchronous buck circuit is used to regulate the charging voltage and current from the energy input terminal to the energy storage medium;

[0066] An input current detection module is coupled between the energy input terminal and the synchronous buck circuit to generate a detection signal that is proportional to the magnitude of the input current flowing through the energy input terminal.

[0067] A reference voltage generation circuit is used to produce a stable, accurate, temperature-independent reference voltage.

[0068] The comparison and control module is used to compare the detection signal with the reference voltage and generate a control signal based on the comparison result to turn on or off the charging path of the synchronous buck circuit.

[0069] The input current detection module is configured to periodically detect current in a pulse manner.

[0070] In the above scheme, the input current detection module includes:

[0071] A detection resistor Rsen is connected in series in the circuit of the energy input terminal to convert the input current into a detection voltage as the detection signal;

[0072] An oscillation signal generation circuit is used to generate a pulse signal with a preset frequency;

[0073] A switching element (N1), controlled by the pulse signal, is used to periodically connect the probe voltage to the comparison and control module.

[0074] In the above scheme, the comparison and control module includes:

[0075] The comparison unit includes a comparator, a reference voltage source that generates a temperature-independent reference voltage VREF, and the comparator is used to compare the sampling voltage VDET of the detection signal output by the input current detection module with the reference voltage VREF.

[0076] The control unit controls the charging operation based on the output of the comparison unit: when VDET > VREF, the charging loop is maintained to operate normally; when VDET < VREF, the charging loop is closed to prevent battery energy from flowing back to the input side or ground.

[0077] In the above scheme, the control unit is integrated in the synchronous buck topology and includes NMOS and PMOS switching elements controlled by drive signals DRVP and DRVN for managing the charging operation of the energy storage medium at the output terminal.

[0078] In the above scheme, the switching element N1 is a MOS switch. When it is turned on under the control of the oscillation signal, it forms a current path from the detection terminal Detector to the ground terminal GND, and generates the sampling voltage VDET on the resistor R2.

[0079] To facilitate a better understanding of the technical concept of this utility model by those skilled in the art, the control methods applicable to the hardware structure of this utility model are illustrated with examples, including the following steps:

[0080] a) Periodically, in a pulsed manner, initiate the detection process of the input current at the energy input terminal;

[0081] b) During the detection process, the magnitude of the input current is measured and converted into a detection signal;

[0082] c) Compare the detected signal with a preset, temperature-stable reference threshold;

[0083] d) If the input current indicated by the detection signal is greater than the minimum operating current defined by the reference threshold, then the charging process to the energy storage medium is initiated or maintained.

[0084] e) If the input current indicated by the detection signal is not greater than the minimum operating current, then the charging path to the energy storage medium is turned off or kept off to prevent current backflow.

[0085] Traditional lithium battery charging management chips, as a charging management solution, receive a relatively fixed and stable input power supply (VIN) and output the slow charging voltage required by the battery. The charging management mechanism is set through the chip's built-in circuitry, typically involving three stages: trickle charging, constant current charging, and constant voltage charging, to achieve conventional battery charging management. However, in charging management systems powered by solar, wind, or generator power sources, the input power is the energy source converted from solar energy into electrical energy, used to power the chip and charge the battery. In this case, the input power supply is severely affected by external conditions such as outdoor weather, sunlight, and wind. Furthermore, with constantly changing weather conditions such as sunshine, rain, snow, or irregular cloud cover, when the energy supply on the energy supply side is weak, electrical energy may flow back from the energy storage side (i.e., the battery side) to the power supply side or discharge to GND. This utility model patent designs a special real-time monitoring and protection scheme specifically for this special situation.

[0086] This invention can also be flexibly adjusted within a certain range by selecting different resistors Rsen, thus achieving different application solutions that meet the usage requirements.

Claims

1. An energy storage control circuit with input-side energy detection function, used to connect the energy input terminal and the energy storage medium, characterized in that, include: A synchronous buck circuit is used to regulate the charging voltage and current from the energy input terminal to the energy storage medium; An input current detection module is coupled between the energy input terminal and the synchronous buck circuit to generate a detection signal that is proportional to the magnitude of the input current flowing through the energy input terminal. A reference voltage generation circuit is used to produce a stable, accurate, temperature-independent reference voltage. The comparison and control module is used to compare the detection signal with the reference voltage and generate a control signal based on the comparison result to turn on or off the charging path of the synchronous buck circuit. The input current detection module is configured to periodically detect current in a pulse manner.

2. The energy storage control circuit according to claim 1, characterized in that, The input current detection module includes: A detection resistor Rsen is connected in series in the circuit of the energy input terminal to convert the input current into a detection voltage as the detection signal; An oscillation signal generation circuit is used to generate a pulse signal with a preset frequency; The switching element N1, controlled by the pulse signal, is used to periodically connect the probe voltage to the comparison and control module.

3. The energy storage control circuit according to claim 1, characterized in that, The comparison and control module includes: The comparison unit includes a comparator, a reference voltage source that generates a temperature-independent reference voltage VREF, and the comparator is used to compare the sampling voltage VDET of the detection signal output by the input current detection module with the reference voltage VREF. The control unit controls the charging operation based on the output of the comparison unit: when VDET > VREF, the charging loop is maintained to operate normally; when VDET < VREF, the charging loop is closed to prevent battery energy from flowing back to the input side or ground.

4. The energy storage control circuit according to claim 3, characterized in that, The control unit is integrated in a synchronous buck topology and includes NMOS and PMOS switching elements controlled by drive signals DRVP and DRVN for managing the charging operation of the energy storage medium at the output.

5. The energy storage control circuit according to claim 2, characterized in that, The switching element N1 is a MOS switch. When it is turned on under the control of the oscillation signal, it forms a current path from the detection terminal Detector to the ground terminal GND, and generates a sampling voltage VDET on the resistor R2.

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