Charging circuit and photovoltaic charging system

Abstract

The invention provides a charging circuit and a photovoltaic charging system. The charging circuit comprises a sampling module, a comparison module, a silicon controlled rectifier module and a first switch module, the sampling module and the first switch module are used for being connected in a charging loop between a charging power supply and a battery, the silicon controlled module is connected with the charging power supply, the first switch module and the comparison module, and the comparison module is further connected with the sampling module; the sampling module is configured to sample the current of the charging loop and output a sampling signal to the comparison module; the comparison module is configured to output a first level signal or a second level signal to the silicon controlled rectifier module based on the size of the sampling signal; the silicon controlled module is configured to be switched on when receiving a first level signal, and outputs a first sub-signal to the first switch module based on the charging power supply; the first switch module is configured to be switched off when the first sub-signal is received, so that the charging loop is switched off. According to the charging circuit, the fault state can be locked when overcurrent occurs, and the working reliability of the circuit is improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of circuit technology, and in particular to a charging circuit and a photovoltaic charging system. Background Art

[0002] In recent years, in order to promote the goals of carbon peak and carbon neutrality, accelerating the construction of a new power system with a high proportion of renewable energy has become an important task in the development of my country's energy industry. In order to convert solar energy into electrical energy and then store it in batteries, whether it is a photovoltaic charger, portable energy storage power supply, household energy storage power supply or commercial energy storage power supply, the photovoltaic charging system will be used in the design of the power supply system.

[0003] In a photovoltaic charging system, photovoltaic power sources often charge batteries through charging circuits. However, many existing charging circuits can interrupt the charging process when abnormal charging current is detected, but they cannot effectively lock the fault state. That is, if the abnormality has not been eliminated, the system may still automatically resume charging, and there is a risk of automatically restarting charging, which may cause repeated occurrence of faults or even damage to the equipment. Summary of the invention

[0004] The embodiments of the present application provide a charging circuit and a photovoltaic charging system, which lock a fault state when an overcurrent occurs, thereby improving the reliability of circuit operation.

[0005] In a first aspect, an embodiment of the present application provides a charging circuit, comprising: a sampling module, a comparison module, a thyristor module and a first switch module. The sampling module and the first switch module are both used to be connected in a charging circuit between a charging power source and a battery, the thyristor module is respectively connected to the charging power source, the first switch module and the comparison module, and the comparison module is also connected to the sampling module. The sampling module is configured to sample the current of the charging circuit and output a sampling signal to the comparison module. The comparison module is configured to output a first level signal or a second level signal to the thyristor module based on the size of the sampling signal. The thyristor module is configured to turn on when receiving the first level signal, and output a first sub-signal to the first switch module based on the charging power source, and to turn off when receiving the second level signal, and output a second sub-signal to the first switch module based on the charging power source. The first switch module is configured to turn off when receiving the first sub-signal, so that the charging circuit is disconnected.

[0006] In some embodiments, the first switch module includes a switch unit, a resistor R1 and a comparison unit; the first end of the switch unit and the first end of the resistor R1 are both connected to the first end of the charging power supply, the second end of the switch unit is connected to the first end of the battery, the second end of the resistor R1 and the control end of the switch unit are both connected to the comparison unit, and the comparison unit is also connected to the thyristor module; wherein the comparison unit is configured to be in a high-impedance state when receiving the first sub-signal, and when the comparison unit is in a high-impedance state, the charging power supply outputs a third level signal to the control end of the switch unit via the resistor R1; the switch unit is configured to be turned off when receiving the third level signal, so that the charging circuit is disconnected.

[0007] In some embodiments, the comparison unit includes a first comparator and a first voltage divider unit; the first voltage divider unit is respectively connected to the first end of the battery and the first input end of the first comparator, and the second input end of the first comparator is connected to the thyristor module; the first voltage divider unit is configured to divide the battery voltage of the battery and output a first voltage divider signal to the comparison unit; the first comparator is configured to compare the voltage magnitudes of the first voltage divider signal and the first sub-signal, or to compare the voltage magnitudes of the first voltage divider signal and the second sub-signal, and output a fourth level signal or be in a high impedance state; the switch unit is also configured to be turned on when receiving the fourth level signal, so that the charging circuit is turned on.

[0008] In some embodiments, the first voltage dividing unit includes a resistor R3 and a resistor R4; the first end of the resistor R3 is connected to the first end of the battery, the second end of the resistor R3 is respectively connected to the first input end of the first comparator and the first end of the resistor R4, and the second end of the resistor R4 is respectively connected to the second end of the battery.

[0009] In some embodiments, the thyristor module includes a thyristor, a voltage-regulating diode and a resistor R2; the first end of the resistor R2 is connected to the first end of the charging power supply, the second end of the resistor R2 is respectively connected to the first end of the comparison module, the first switch module, the anode of the thyristor and the cathode of the voltage-regulating diode, the cathode of the thyristor and the anode of the voltage-regulating diode are both grounded, and the gate of the thyristor is connected to the second end of the comparison module.

[0010] In some embodiments, the comparison module includes a second comparator, a resistor R9 and a second voltage divider unit; the first input end of the second comparator is connected to the sampling module, the second input end of the second comparator is connected to the second voltage divider unit, the second voltage divider unit is also connected to the first end of the thyristor module, the output end of the second comparator is connected to the first end of the resistor R9 and the second end of the thyristor module, and the second end of the resistor R9 is connected to the first end of the charging power supply; wherein the second voltage divider unit is configured to divide the power supply voltage of the charging power supply and output a second voltage divider signal; the second comparator is configured to compare the voltage magnitudes of the sampling signal and the second voltage divider signal, output the first level signal or be in a high impedance state; the resistor R9 is configured to output the second level signal to the thyristor module based on the charging power supply when the second comparator is in a high impedance state.

[0011] In some embodiments, the second voltage dividing unit includes a resistor R7 and a resistor R8; the first end of the resistor R7 is connected to the first end of the thyristor module, the second end of the resistor R7 is respectively connected to the second input end of the second comparator and the first end of the resistor R8, and the second end of the resistor R8 is grounded.

[0012] In some embodiments, the sampling module includes a resistor R5, a resistor R6 and a capacitor C2; the first end of the resistor R5 is respectively connected to the first end of the resistor R6, the first end of the capacitor C2 and the second end of the battery, the second end of the resistor R5 is connected to the second end of the charging power supply, and the second end of the resistor R6 is respectively connected to the second end of the capacitor C2 and the comparison module.

[0013] In some embodiments, the charging circuit further includes a second switch module and / or a third switch module; the second switch module is respectively connected to the charging power supply and the first switch module, and the third switch module is respectively connected to the battery and the first switch module.

[0014] In a second aspect, an embodiment of the present application further provides a photovoltaic charging system, the photovoltaic charging system comprising a charging power source, a battery, and a charging circuit as described in any one embodiment of the first aspect. The charging power source is connected to the battery through the charging circuit.

[0015] Compared with the prior art, the beneficial effects of the present application are as follows: Different from the prior art, the present application provides a charging circuit and a photovoltaic charging system, including a sampling module, a comparison module, a thyristor module and a first switch module; the sampling module and the first switch module are both used to connect in the charging circuit between the charging power supply and the battery, the thyristor module is respectively connected to the charging power supply, the first switch module and the comparison module, and the comparison module is also connected to the sampling module; the sampling module is configured to sample the current of the charging circuit and output a sampling signal to the comparison module; the comparison module is configured to output a first level signal or a second level signal to the thyristor module based on the size of the sampling signal; the thyristor module is configured to turn on when receiving the first level signal, and output a first sub-signal to the first switch module based on the charging power supply, and turn off when receiving the second level signal, and output a second sub-signal to the first switch module based on the charging power supply; the first switch module is configured to turn off when receiving the first sub-signal, so that the charging circuit is disconnected. The charging circuit can lock the fault state when overcurrent occurs, thereby improving the reliability of the circuit operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements / modules and steps with the same reference numerals in the drawings are represented as similar elements / modules and steps. Unless otherwise specified, the figures in the drawings do not constitute proportional limitations.

[0017] Figure 1 is a structural block diagram of a charging circuit provided in an embodiment of the present application;

[0018] Figure 2 It is a structural diagram of a charging circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0019] The present application is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements can also be made without departing from the concept of the present application. These all belong to the protection scope of the present application.

[0020] For ease of understanding of the present application, the present application is described in more detail below in conjunction with the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those generally understood by those skilled in the art of the present application. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not used to limit the present application. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.

[0021] It should be noted that, if there is no conflict, the various features in the embodiments of the present application can be combined with each other, all within the scope of protection of the present application. In addition, although the functional module division is performed in the device schematic, in some cases, the module division can be different from that in the device. In addition, the words "first", "second", etc. used herein do not limit the data and execution order, but only distinguish the same items or similar items with basically the same functions and effects.

[0022] The current charging circuit cannot lock the fault state after a fault occurs, which may cause the system to restart charging without clearing the fault. In addition, in order to provide basic protection functions, some existing designs have multiple protection components and control modules, which makes the design complex and increases the cost. It also increases the difficulty of circuit maintenance and fault diagnosis, especially in application scenarios with limited space. This problem is particularly prominent. In addition, when an input abnormality is detected, the existing charging circuit has a slow response speed and may be difficult to lock the fault and interrupt the output in time, causing the system to frequently suffer unnecessary shocks in a short period of time. This design defect of delayed response can easily cause irreversible damage to photovoltaic panels and batteries.

[0023] In order to improve the above problems, the embodiments of the present application provide a charging circuit and a photovoltaic charging system, which can stop charging when a current abnormality is detected, and charging can only be resumed when the charging power supply is reconnected. That is, when an overcurrent fault occurs, the fault state can be locked, thereby improving the safety and reliability of the charging operation.

[0024] In a first aspect, the present application embodiment provides a charging circuit 100, see Figure 1 The charging circuit 100 includes: a sampling module 10 , a comparison module 20 , a thyristor module 30 and a first switch module 40 .

[0025] The sampling module 10 and the first switch module 40 are both used to be connected in the charging circuit between the charging power supply 200 and the battery 300. The thyristor module 30 is respectively connected to the charging power supply 200, the first switch module 40 and the comparison module 20, and the comparison module 20 is also connected to the sampling module 10. The sampling module 10 is configured to sample the current of the charging circuit and output the sampling signal to the comparison module 20. The comparison module 20 is configured to output a first level signal or a second level signal to the thyristor module 30 based on the size of the sampling signal. The thyristor module 30 is configured to turn on when receiving the first level signal, and output a first sub-signal to the first switch module 40 based on the charging power supply 200, and to turn off when receiving the second level signal, and output a second sub-signal to the first switch module 40 based on the charging power supply 200. The first switch module 40 is configured to turn off when receiving the first sub-signal to disconnect the charging circuit.

[0026] The charging power supply 200 is a device or system that can provide electric energy to a battery or other energy storage device, and may include devices such as a rectifier device and a filter device. In some implementations, the charging power supply 200 may be a photovoltaic charging power supply, which refers to a device that uses the photovoltaic effect to convert solar energy into electric energy and charges a battery or other energy storage device.

[0027] The battery 300 is a device for storing energy, which may include one battery cell, or may include at least two battery cells connected in series and / or in parallel.

[0028] The charging circuit refers to the current circuit formed when the charging power source 200 charges the battery 200. The sampling module 10 is used to connect in the charging circuit between the charging power source 200 and the battery 300, which means that the sampling module 10 is connected between the first end of the charging power source 200 and the first end of the battery 200, or the sampling module 10 is connected between the second end of the charging power source 200 and the second end of the battery 300. The first switch module 40 is used to connect in the charging circuit between the charging power source 200 and the battery 300, which means that the first switch module 40 is connected between the first end of the charging power source 200 and the first end of the battery 200, or the first switch module 40 is connected between the second end of the charging power source 200 and the second end of the battery 300.

[0029] As an example but not a limitation, the first level signal is a high level signal, and the second level signal is a low level signal.

[0030] The thyristor module 30 includes a thyristor, which is also called a thyristor. After the thyristor is turned on, the gate electrode will lose its function, that is, the thyristor can no longer be turned off by the gate electrode, and it will always be turned on. It is necessary to disconnect the power supply of the anode or make the anode current less than the minimum current value to maintain the conduction before the gate electrode can be used again to control the thyristor to turn on or off. In the thyristor module 30, the thyristor is turned on when the thyristor module 30 is turned on, and the thyristor is turned off when the thyristor module 30 is turned off.

[0031] In the charging circuit 100, when the current of the charging circuit is less than or equal to the preset current threshold, the sampling signal output by the sampling module 10 is small, and the second level signal output by the comparison module 20 based on the sampling signal will turn off the thyristor module 30, and the thyristor module 30 outputs the second sub-signal. At this time, the first switch module 40 will not perform the overcurrent protection action. When the current of the charging circuit is greater than the preset current threshold, the sampling signal output by the sampling module 10 is too large, and the first level signal output by the comparison module 20 based on the sampling signal will turn on the thyristor module 30, and the thyristor module 30 will output the first sub-signal to the first switch module 40, and the first switch module 40 will be turned off, the charging circuit is disconnected, and the charging power supply 200 cannot charge the battery 300. Moreover, due to the characteristics of the thyristor in the thyristor module 30, the thyristor module 30 will continue to be turned on after being turned on, that is, the thyristor module 30 always outputs the first sub-signal to the first switch module 40 based on the charging power supply 200, and the first switch module 40 always maintains the disconnected state, so that the charging circuit is always disconnected until the charging power supply 200 reconnects the charging circuit 200 and the current of the charging circuit is less than the preset current threshold. Among them, the preset current threshold can be the maximum allowable charging current value when the charging power supply 200 charges the battery 300.

[0032] It can be seen that in the charging circuit 100 provided in the present application, when a current abnormality is detected, not only can the first switch module 40 be turned off, so that the charging power source 200 cannot charge the battery 300, but also the fault state can be locked, and the charging power source 200 must be disconnected and then reconnected to recharge, thereby improving the safety and reliability of the charging circuit 200. Moreover, the circuit structure is simple, reducing the complexity and cost of the system.

[0033] In some of these embodiments, see Figure 2 The sampling module 10 includes a resistor R5, a resistor R6 and a capacitor C2. The first end of the resistor R5 is respectively connected to the first end of the resistor R6, the first end of the capacitor C2 and the second end of the battery 300, the second end of the resistor R5 is connected to the second end of the charging power source 200, and the second end of the resistor R6 is respectively connected to the second end of the capacitor C2 and the comparison module 20.

[0034] As an example but not limitation, in the present application, the first end of the battery 300 is the positive electrode of the battery 300, the second end of the battery 300 is the negative electrode of the battery 300, the first end of the charging power supply 200 is the positive electrode of the charging power supply 200, and the second end of the charging power supply 200 is the negative electrode of the charging power supply 200. Normally, the negative electrode of the charging power supply 200 is grounded.

[0035] In the sampling module 10, when the charging power source 200 charges the battery 300, the charging current will flow through the resistor R5, and a voltage signal will be generated at the second end of the resistor R5. The voltage signal is filtered by the resistor R6 and the capacitor C2 and then output to the comparison module 20. The filtered voltage signal is also the sampling signal. The subsequent comparison module 20 can output a corresponding signal according to the size of the sampling signal.

[0036] In some of these embodiments, see Figure 1 and Figure 2 , the first switch module 40 includes a switch unit 41, a resistor R1 and a comparison unit 42. The first end of the switch unit 41 and the first end of the resistor R1 are both connected to the first end of the charging power supply 200, the second end of the switch unit 41 is connected to the first end of the battery 200, the second end of the resistor R2 and the control end of the switch unit 41 are both connected to the comparison unit 42, and the comparison unit 42 is also connected to the thyristor module 30. Among them, the comparison unit 42 is configured to be in a high impedance state when receiving the first sub-signal, and when the comparison unit 42 is in a high impedance state, the charging power supply 200 outputs a third level signal to the control end of the switch unit 41 through the resistor R1. The switch unit 41 is configured to be turned off when receiving the third level signal, so that the charging circuit is disconnected.

[0037] The switch unit 41 refers to a device that can establish or disconnect the connection between the charging power source 200 and the battery 300, which may include but is not limited to a relay, a MOS tube, an IGBT tube, and other suitable switch devices. Figure 2 , the switch unit 41 includes a PMOS tube Q1 and a PMOS tube Q2, the source of the PMOS tube Q1 is connected to the first end of the charging power source 200, the drain of the PMOS tube Q1 is connected to the drain of the PMOS tube Q2, the source of the PMOS tube Q2 is connected to the first end of the battery 300, and the gate of the PMOS tube Q1 and the gate of the PMOS tube Q2 are both connected to the second end of the resistor R1. In this implementation, by connecting two PMOS tubes as the switch unit 41, not only can it be turned on or off based on the gate signal, but it can also prevent the charging power source from being damaged by reverse injection caused by mistakenly connecting to a high-voltage energy storage device, thereby improving the safety of circuit operation.

[0038] Specifically, the third level signal is a high level signal. In the charging circuit, the comparison unit 42 is in a high impedance state when receiving the first sub-signal, that is, the comparison unit 42 neither outputs a high level signal nor a low level signal, and it is in an open circuit state relative to the external circuit. Then, at this time, the charging power supply 200 will output a high level signal to the switch unit 41 through the resistor R1, and the switch unit 41 will be disconnected, and the charging power supply 200 cannot charge the battery 300.

[0039] It can be seen that in this embodiment, by providing the above-mentioned devices, it can be ensured that the first switch module 40 can be turned off based on the signal output by the thyristor module 30 to achieve a protection action.

[0040] In some of these embodiments, see Figure 2 , the comparison unit 42 includes a first comparator U1 and a first voltage dividing unit 421. The first voltage dividing unit 421 is respectively connected to the first end of the battery 300 and the first input end of the first comparator U1, and the second input end of the first comparator U1 is connected to the thyristor module 30. The first voltage dividing unit 421 is configured to divide the battery voltage of the battery 300 and output a first voltage dividing signal to the comparison unit 42. The first comparator U1 is configured to compare the voltage magnitudes of the first voltage dividing signal and the first sub-signal, or compare the voltage magnitudes of the first voltage dividing signal and the second sub-signal, and output a fourth level signal or be in a high impedance state.

[0041] The battery voltage refers to the voltage between the positive and negative electrodes of the battery 200, and the fourth level signal is a low level signal. As an example but not a limitation, the first comparator U1 can use the LM2903DMR2G device, the first input terminal of the first comparator U1 is the inverting input terminal, and the second input terminal of the first comparator U1 is the non-inverting input terminal. For the first comparator U1, when the voltage of the inverting input terminal is higher than the voltage of the non-inverting input terminal, the first comparator U1 outputs a low level signal, and when the voltage of the non-inverting input terminal is higher than the voltage of the inverting input terminal, the first comparator U1 is in a high impedance state. In practical applications, the first comparator U1 can also use other suitable comparison devices.

[0042] The first voltage dividing unit 421 can divide the power supply voltage by voltage distribution between resistors (or other voltage dividing elements). Figure 2 The first voltage dividing unit 421 includes a resistor R3 and a resistor R4; the first end of the resistor R3 is connected to the first end of the battery 300, the second end of the resistor R3 is respectively connected to the first input end of the first comparator U1 and the first end of the resistor R4, and the second end of the resistor R4 is respectively connected to the second end of the battery 300. The number and resistance value of the resistors included in the first voltage dividing unit 421 can be determined according to actual needs and are not limited here.

[0043] In the charging circuit, the resistor R3 and the resistor R4 can divide the battery voltage of the battery 300, and input the first divided voltage signal to the non-inverting input terminal of the first comparator U1, and the thyristor module 40 inputs the first sub-signal or the second sub-signal to the inverting input terminal of the first comparator U1. When the current of the charging circuit is less than the preset current threshold, that is, when the thyristor module 30 is turned off, if the battery voltage is less than the preset voltage threshold, the voltage of the first divided voltage signal is less than the voltage of the second sub-signal. At this time, the non-inverting input terminal of the first comparator U1 is less than the inverting input terminal of the first comparator U1, and the first comparator U1 outputs a low voltage. The first voltage-divided signal (fourth level signal) is received by the first comparator U1, so that the switch unit 41 is turned on, and the charging power supply 200 can charge the battery 300 normally. If the battery voltage is greater than the preset voltage threshold, the voltage of the first voltage-divided signal is greater than the voltage of the second sub-signal. At this time, the inverting input terminal of the first comparator U1 is less than the non-inverting input terminal of the first comparator U1, and the first comparator U1 outputs a high impedance state. The control terminal of the switch unit 41 is pulled up to the level of the charging power supply 200 through the resistor R1, that is, the control terminal of the switch unit 41 receives the high level signal (third level signal), the switch unit 41 is disconnected, and the charging power supply 200 cannot charge the battery 300. Among them, the preset voltage threshold can be the maximum allowable voltage value of the battery 300. The first voltage-divided signal can be set based on the preset voltage threshold and the resistance values ​​of the third resistor R3 and the fourth resistor R4, so as to realize turning on or off the charging circuit according to the size of the battery voltage, thereby avoiding overcharging of the battery 300.

[0044] In addition, when the current of the charging circuit is greater than the preset current threshold, that is, when the thyristor module 40 is turned on, the inverting input terminal of the first comparator U1 is the second sub-signal, and the voltage of the second sub-signal is less than the non-inverting input terminal of the first comparator U1. The first comparator U1 outputs a high-impedance state, and the control terminal of the switch unit 41 is pulled up to the level of the charging power supply 200 through the resistor R1. The control terminal of the switch unit 41 receives a high-level signal (third-level signal), and the switch unit 41 is disconnected to perform a protection action.

[0045] It can be seen that the comparison unit 42 provided in this embodiment can turn on or off the switch unit 41 based on the size of the battery voltage to avoid overcharging of the battery 300 when no current fault occurs. When overcurrent occurs, the switch unit 41 can be turned off based on the first sub-signal output by the thyristor module 30 to achieve overcurrent protection.

[0046] In some of these embodiments, see Figure 2The thyristor module 30 includes a thyristor S1, a voltage-stabilizing diode D1 and a resistor R2. The first end of the resistor R2 is connected to the first end of the charging power source 200, the second end of the resistor R2 is respectively connected to the first end of the comparison module 20, the first switch module 40, the anode of the thyristor S1 and the cathode of the voltage-stabilizing diode D1, the cathode of the thyristor S1 and the anode of the voltage-stabilizing diode D1 are both grounded, and the gate of the thyristor S1 is connected to the second end of the comparison module 20.

[0047] Specifically, the cathode of the thyristor S1 and the anode of the zener diode D1 are grounded through the resistor R5 in the sampling module 10, and the anode of the thyristor S1, the second end of the resistor R2 and the cathode of the zener diode D1 are connected to the second input end of the first comparator U1 and the first end of the comparison module 20. The zener diode D1 can keep the voltage at both ends relatively stable. In the thyristor module 30, when the thyristor S1 is disconnected, the charging power supply 200, the resistor R2, the zener diode D1, the resistor R5 and the ground form a loop, and the zener diode D1 can make the second input end of the first comparator U1 at a stable voltage value, that is, even if the second input end of the first comparator U1 receives a stable voltage signal, the stable voltage signal is the second sub-signal; when the thyristor S1 is turned on, the second input end of the first comparator U1 is pulled down to 0 by the thyristor S1 and the resistor R5, so that the first switch module 40 receives the first sub-signal.

[0048] It can be seen that the thyristor module 30 provided in this embodiment can input the first sub-signal or the second sub-signal to the first switch module 40 when the thyristor S1 is turned on or off.

[0049] In some of these embodiments, see Figure 2 , the comparison module 20 includes a second comparator U2, a resistor R9 and a second voltage divider unit 21. The first input end of the second comparator U2 is connected to the sampling module 10, the second input end of the second comparator U2 is connected to the second voltage divider unit 21, the second voltage divider unit 21 is also connected to the first end of the thyristor module 30, the output end of the second comparator U2 is connected to the first end of the resistor R9 and the second end of the thyristor module 30, and the second end of the resistor R9 is connected to the first end of the charging power supply 200. Among them, the second voltage divider unit 21 is configured to divide the power supply voltage of the charging power supply 200 and output a second voltage divider signal; the second comparator U2 is configured to compare the voltage magnitudes of the sampling signal and the second voltage divider signal, output a first level signal or be in a high impedance state; the resistor R9 is configured to output a second level signal to the thyristor module based on the charging power supply when the second comparator U2 is in a high impedance state.

[0050] The power supply voltage refers to the voltage between the positive electrode and the negative electrode of the charging power supply 200. The second voltage dividing unit 21 can divide the power supply voltage by voltage distribution between resistors (or other voltage dividing elements). Figure 2 The second voltage dividing unit 21 includes a resistor R7 and a resistor R8. The first end of the resistor R7 is connected to the first end of the thyristor module 30, the second end of the resistor R7 is respectively connected to the second input end of the second comparator U2 and the first end of the resistor R8, and the second end of the resistor R8 is grounded. For example, the first end of the resistor R7 is connected to the second end of the resistor R2.

[0051] As an example but not a limitation, the second comparator U2 can use an LM2903DMR2G device, the first input end of the second comparator U2 is an inverting input end, the second input end of the second comparator U2 is a non-inverting input end, and the output end of the second comparator U2 is connected to the first end of the resistor R9 and the gate of the thyristor S1. For the second comparator U2, when the voltage at the inverting input end is higher than the voltage at the non-inverting input end, the second comparator U2 outputs a low-level signal, and when the voltage at the non-inverting input end is higher than the voltage at the inverting input end, the output end of the second comparator U2 is in a high-impedance state, that is, in an open circuit state. In practical applications, the second comparator U2 can also use other suitable comparison devices.

[0052] In the comparison module 20, the charging power supply 200, the resistor R2, the resistor R7 and the resistor R8 form a loop, and a second voltage-divided signal is generated at the first end of the resistor R8 to the inverting input end of the second comparator U2. By adjusting the resistance values ​​of the resistors R7 and R8, when the current of the charging circuit is less than or equal to the preset current threshold, the sampling signal is less than the second voltage-divided signal, the voltage of the in-phase input end of the second comparator U2 is less than the voltage of the inverting input end of the second comparator U2, and the second comparator U2 outputs a low-level signal; when the current of the charging circuit is greater than the preset current threshold, the sampling signal is greater than the second voltage-divided signal, the voltage of the inverting input end of the second comparator U2 is less than the voltage of the in-phase input end of the second comparator U2, and the second comparator U2 is in a high-impedance state, and the gate of the thyristor S1 is pulled up to the level of the charging power supply 200 by the resistor R9, that is, the thyristor S1 receives a high-level signal. The preset current threshold is the maximum allowable current value when the charging power supply 200 charges the battery 300.

[0053] It can be seen that the comparison module 20 provided in this embodiment can output a corresponding signal to the thyristor module 30 based on the current size of the charging circuit.

[0054] In some of these embodiments, see Figure 2 The charging circuit further includes a second switch module 50 and / or a third switch module 60; the second switch module 50 is respectively connected to the charging power source 200 and the first switch module 40, and the third switch module 60 is respectively connected to the battery 300 and the first switch module 40.

[0055] The second switch module 50 may include a switch S3, one end of which is connected to the charging power source 200, and the other end of which is connected to the switch tube Q1. The third switch module 60 may include a switch S2. The switch S2 and the switch S3 may use appropriate switch devices in the prior art, which are not limited here.

[0056] By providing the second switch module 50 and / or the third switch module 60 , the connection between the charging power source 200 and the battery 300 and the charging circuit 100 can be disconnected.

[0057] Combine the following Figure 2 The illustrated embodiment describes in detail the specific working process of the charging circuit 100 provided in the present application.

[0058] First, when the switch S2 is closed, the switch S3 is closed, the switch tube Q1 is turned off, the switch tube Q2 is turned off, and the thyristor S1 is turned off, the charging power supply 200, the resistor R2, the resistor R7, and the resistor R8 form a current loop, and the inverting input terminal of the second comparator U2 receives the second voltage-divided signal output by the current loop, and under the action of the voltage-stabilizing diode D1, the voltage of the second sub-signal received by the inverting input terminal of the second comparator U2 is equal to the voltage-stabilizing value of the voltage-stabilizing diode D1. If the battery voltage of the battery 300 is less than the preset voltage threshold, the voltage of the first voltage-divided signal is less than the voltage of the second sub-signal, the voltage of the non-inverting input terminal of the first comparator U1 is less than the voltage of the inverting input terminal, and the first comparator U1 outputs a low-level signal, and the switch tubes Q1 and Q2 are turned on, so that the charging power supply 200 charges the battery 300. If the battery voltage is greater than the preset voltage threshold, the voltage of the first voltage-divided signal is greater than the voltage of the second sub-signal. At this time, the inverting input terminal of the first comparator U1 is less than the non-inverting input terminal of the first comparator U1, and the first comparator U1 outputs a high-impedance state. The gate of the switch tube Q1 and the gate of the switch tube Q2 are pulled up to the level of the charging power supply 200 through the resistor R1, that is, the gate of the switch tube Q1 and the gate of the switch tube Q2 receive a high-level signal (third-level signal), the switch tube Q1 and the switch tube Q2 are disconnected, and the charging power supply 200 cannot charge the battery 300. That is, the charging circuit provided in the present application can turn on or off the charging circuit based on the size of the battery voltage to prevent the battery 300 from overcharging.

[0059] In addition, if the current of the charging circuit is greater than the preset current threshold, the sampling signal is greater than the second voltage-divided signal, the inverting input terminal of the second comparator U2 is less than the non-inverting input terminal of the second comparator U2, the second comparator U2 is in a high-resistance state, and the gate of the thyristor S1 is pulled up to the level of the charging power source 200 by the resistor R9, that is, the thyristor S1 receives a high-level signal, the thyristor S1 is turned on, and the second input terminal of the first comparator U1 is pulled down to 0 by the thyristor S1 and the resistor R5, so that the first switch module 40 receives The first sub-signal is smaller than the first voltage-divided signal, that is, the inverting input terminal of the first comparator U1 is smaller than the non-inverting input terminal of the first comparator U1, the first comparator U1 outputs a high impedance state, the gate of the switch tube Q1 and the gate of the switch tube Q2 are pulled up to the level of the charging power supply 200 through the resistor R1, that is, the gate of the switch tube Q1 and the gate of the switch tube Q2 receive a high-level signal (third-level signal), the switch tube Q1 and the switch tube Q2 are disconnected, and the charging power supply 200 cannot charge the battery 300.

[0060] It can be seen that the present application can also turn off the first switch module 40 when the current is abnormal, so that the charging power supply 200 cannot charge the battery 300, and due to the conduction characteristics of the thyristor S1, after it is turned on, the gate will lose its control function, and the thyristor S1 will remain turned on. That is, the loop between the charging power supply 200, the resistor R2, the thyristor S1, the resistor R5 and the ground always forms a current loop, and the inverting input end of the first comparator U1 is always smaller than the non-inverting input end, so that the switch tube Q1 and the switch tube Q2 are always turned off, and the fault is locked. Only after the charging power supply 200 is disconnected from the charging circuit, the above loop no longer has current, so that the thyristor S1 is disconnected. When the charging power supply 200 is reconnected to the circuit and the current of the charging circuit is less than the preset current threshold, the thyristor S1 can be in a disconnected state without affecting the operation of the charging circuit.

[0061] In addition, the charging circuit provided in the present application uses fewer circuit components and has a simple structure, which reduces the complexity and cost of the system, can achieve overcurrent protection and overcharge protection, and can adapt to charging power supplies and batteries with different voltages by adjusting the resistance value of the sampling resistor R5.

[0062] In a second aspect, an embodiment of the present application provides a photovoltaic charging system, which includes a charging power source 200, a battery 300, and a charging circuit 100 as described in any one of the first aspects; the charging power source 200 is connected to the battery 300 through the charging circuit 100.

[0063] In this embodiment, the charging circuit 100 has the same structure and function as the charging circuit 100 described in any one of the embodiments of the first aspect, and will not be described in detail herein.

[0064] It should be noted that the device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Under the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes in different aspects of the present application as described above, which are not provided in detail for the sake of simplicity. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A charging circuit, characterized in that: include: A sampling module, a comparison module, a thyristor module and a first switch module; The sampling module and the first switch module are both used to be connected in a charging circuit between a charging power source and a battery, the thyristor module is respectively connected to the charging power source, the first switch module and the comparison module, and the comparison module is also connected to the sampling module; The sampling module is configured to sample the current of the charging circuit and output a sampling signal to the comparison module; The comparison module is configured to output a first level signal or a second level signal to the thyristor module based on the size of the sampling signal; The thyristor module is configured to be turned on when receiving the first level signal, and output a first sub-signal to the first switch module based on the charging power supply, and to be turned off when receiving the second level signal, and output a second sub-signal to the first switch module based on the charging power supply; The first switch module is configured to be turned off upon receiving the first sub-signal, so as to disconnect the charging loop.

2. The charging circuit according to claim 1, characterized in that: The first switch module includes a switch unit, a resistor R1 and a comparison unit; The first end of the switch unit and the first end of the resistor R1 are both connected to the first end of the charging power supply, the second end of the switch unit is connected to the first end of the battery, the second end of the resistor R1 and the control end of the switch unit are both connected to the comparison unit, and the comparison unit is also connected to the thyristor module; Wherein, the comparison unit is configured to be in a high impedance state when receiving the first sub-signal, and when the comparison unit is in the high impedance state, the charging power supply outputs a third level signal to the control end of the switch unit via the resistor R1; The switch unit is configured to be turned off upon receiving the third level signal, so as to disconnect the charging loop.

3. The charging circuit according to claim 2, characterized in that: The comparison unit includes a first comparator and a first voltage dividing unit; The first voltage dividing unit is respectively connected to the first end of the battery and the first input end of the first comparator, and the second input end of the first comparator is connected to the thyristor module; The first voltage dividing unit is configured to divide the battery voltage of the battery and output a first voltage dividing signal to the comparison unit; The first comparator is configured to compare the voltage magnitudes of the first divided voltage signal and the first sub-signal, or to compare the voltage magnitudes of the first divided voltage signal and the second sub-signal, and output a fourth level signal or be in a high impedance state; The switch unit is further configured to be turned on when receiving the fourth level signal, so as to turn on the charging loop.

4. The charging circuit according to claim 3, characterized in that: The first voltage dividing unit includes a resistor R3 and a resistor R4; The first end of the resistor R3 is connected to the first end of the battery, the second end of the resistor R3 is respectively connected to the first input end of the first comparator and the first end of the resistor R4, and the second end of the resistor R4 is respectively connected to the second end of the battery.

5. The charging circuit according to claim 1, characterized in that: The thyristor module includes a thyristor, a voltage regulator diode and a resistor R2; The first end of the resistor R2 is connected to the first end of the charging power supply, the second end of the resistor R2 is respectively connected to the first end of the comparison module, the first switch module, the anode of the thyristor and the cathode of the voltage regulator diode, the cathode of the thyristor and the anode of the voltage regulator diode are both grounded, and the gate of the thyristor is connected to the second end of the comparison module.

6. The charging circuit according to claim 1, characterized in that: The comparison module includes a second comparator, a resistor R9 and a second voltage dividing unit; The first input end of the second comparator is connected to the sampling module, the second input end of the second comparator is connected to the second voltage dividing unit, the second voltage dividing unit is also connected to the first end of the thyristor module, the output end of the second comparator is connected to the first end of the resistor R9 and the second end of the thyristor module, and the second end of the resistor R9 is connected to the first end of the charging power supply; Wherein, the second voltage dividing unit is configured to divide the power supply voltage of the charging power supply and output a second voltage dividing signal; The second comparator is configured to compare the voltage magnitudes of the sampling signal and the second voltage-divided signal, and output the first level signal or be in a high impedance state; The resistor R9 is configured to output the second level signal to the thyristor module based on the charging power source when the second comparator is in a high impedance state.

7. The charging circuit according to claim 6, characterized in that: The second voltage dividing unit includes a resistor R7 and a resistor R8; The first end of the resistor R7 is connected to the first end of the thyristor module, the second end of the resistor R7 is respectively connected to the second input end of the second comparator and the first end of the resistor R8, and the second end of the resistor R8 is grounded.

8. The charging circuit according to any one of claims 1 to 7, characterized in that: The sampling module includes a resistor R5, a resistor R6 and a capacitor C2; The first end of the resistor R5 is respectively connected to the first end of the resistor R6, the first end of the capacitor C2 and the second end of the battery, the second end of the resistor R5 is connected to the second end of the charging power supply, and the second end of the resistor R6 is respectively connected to the second end of the capacitor C2 and the comparison module.

9. The charging circuit according to any one of claims 1 to 7, characterized in that: The charging circuit further includes a second switch module and / or a third switch module; The second switch module is respectively connected to the charging power source and the first switch module, and the third switch module is respectively connected to the battery and the first switch module.

10. A photovoltaic charging system, characterized in that: Comprising a charging power source, a battery, and a charging circuit as claimed in any one of claims 1 to 9; The charging power source is connected to the battery through the charging circuit.

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