Charging circuit, charger and energy storage terminal

Abstract

The application provides a charging circuit, a charger and an energy storage terminal. The charging circuit comprises an input module for inputting voltage; a power module connected with the input module, comprising a boost-buck unit, the boost-buck unit comprising a boost mode and a buck mode, for converting the voltage input by the input module into the voltage required by a charging battery through the boost mode or the buck mode; a control module connected with the power module, for controlling the power module to perform boost or buck conversion; and an output module connected with the power module, for outputting the voltage converted by the power module to the charging battery. The application can realize wide voltage range input and high power charging of the charging battery.

Description

Technical Field

[0001] This application relates to the field of charging technology, and in particular to a charging circuit, a charger, and an energy storage terminal. Background Technology

[0002] With the increasing prevalence of information technology and electronics in people's lives, the demand for electricity is also rising. To address this increased demand and the need for backup power, various types of energy storage products have emerged. These energy storage products incorporate large-capacity lithium batteries to maximize their range. Furthermore, to facilitate charging, multiple charging methods are often incorporated into the design of energy storage products, such as mains charging, photovoltaic charging, and on-board charging, providing flexible charging options.

[0003] Using multiple charging interfaces, such as DC charging interfaces, photovoltaic charging interfaces, and vehicle charging interfaces, generally requires a dedicated control chip for charging. However, the maximum input voltage supported by a dedicated control chip is only 40V. Furthermore, when the number of series of rechargeable batteries built into the energy storage product exceeds a certain number (e.g., 6 series), the dedicated control chip becomes difficult to meet the product's design requirements. In addition, the maximum charging power of such dedicated control chips is only 100W, which is also insufficient to meet the charging needs of high-power energy storage products. Summary of the Invention

[0004] This application provides a charging circuit, a charger, and an energy storage terminal to solve the problems of input voltage and charging power limitations of dedicated control chips in the prior art.

[0005] In a first aspect, this application provides a charging circuit, the charging circuit comprising: Input module, used for input voltage; A power module, connected to the input module, includes a buck-boost unit, which includes a boost mode and a buck mode, for converting the voltage input to the input module into the voltage required by the rechargeable battery through the boost mode or the buck mode; A control module, connected to the power module, is used to control the power module to perform boost or buck conversion; An output module, which is connected to the power module, is used to output the voltage converted by the power module to the rechargeable battery.

[0006] In one embodiment of this application, the control module includes an MCU, which is used to output a drive signal to the buck-boost unit to realize a boost mode or a buck mode. When the MCU compares the voltage input through the input module to be lower than the voltage of the rechargeable battery, it controls the buck-boost unit to switch to boost mode. When the MCU compares the voltage input through the input module to be higher than the voltage of the rechargeable battery, it controls the buck-boost unit to switch to buck mode.

[0007] In one embodiment of this application, the control module further includes a drive unit. The MCU outputs the drive signal required by the buck-boost unit through the drive unit, and controls the buck-boost unit to achieve boost mode or buck mode through the drive unit.

[0008] In one embodiment of this application, the buck-boost unit includes an energy storage inductor and first to fourth switching transistors respectively connected to the energy storage inductor. Each switching transistor is connected to the driving unit and corresponds to one driving signal output by the driving unit. The driving signals corresponding to the first and second switching transistors are two complementary driving signals, and the driving signals corresponding to the third and fourth switching transistors are two other complementary driving signals. When the buck-boost unit operates in boost mode, the first and second switching transistors operate in a switching state, and the third and fourth switching transistors operate in a boost conversion state. When the buck-boost unit operates in buck mode, the third and fourth switching transistors operate in a switching state, and the first and second switching transistors operate in a buck conversion state.

[0009] In one embodiment of this application, the control module further includes a first voltage sensor, the input terminal of which is connected to the positive and negative terminals of the input module respectively, and its output terminal is connected to the MCU. The first voltage sensor is used to detect whether the input module has an external power supply.

[0010] In one embodiment of this application, the power module further includes a first shunt, and the control module further includes a first operational amplifier. The first shunt is connected in series with the positive terminal of the input module and is connected to the relay, the buck-boost unit, and the first operational amplifier respectively. The first operational amplifier is connected to the MCU. The first shunt converts the current signal input from the external power supply into a voltage signal and then converts it into a voltage signal within a preset range through the first operational amplifier to be sent to the sampling terminal of the MCU.

[0011] In one embodiment of this application, the control module further includes a second voltage sensor. The input terminal of the second voltage sensor is connected to the positive and negative terminals of the rechargeable battery, respectively, and its output terminal is connected to the MCU. The second voltage sensor is used to detect whether the charging circuit is connected to the rechargeable battery.

[0012] In one embodiment of this application, the power module further includes a second shunt, and the control module further includes a second operational amplifier. The second shunt is connected in series with the positive terminal of the rechargeable battery and is connected to the buck-boost unit, the output module, and the second operational amplifier respectively. The second operational amplifier is connected to the MCU. The second shunt converts the current signal of the rechargeable battery into a voltage signal and then converts it into a voltage signal within a preset range through the second operational amplifier to be sent to the sampling terminal of the MCU.

[0013] In one embodiment of this application, the control module further includes a self-locking unit, which is connected to the MCU and the drive unit respectively. The self-locking unit is used to prevent the two complementary drive signals output by the MCU from being simultaneously turned on when the charging circuit is powered on or off.

[0014] In one embodiment of this application, the self-locking unit includes a first self-locking unit, which includes a first transistor, a second transistor, a first resistor, a second resistor, a third resistor, and a fourth resistor. The first input port of the first self-locking unit is connected to the emitter of the first transistor and one end of the second resistor, respectively. The other end of the second resistor is connected to the base of the second transistor. The collector of the first transistor is connected to the first output port and one end of the third resistor, respectively. The other end of the third resistor is grounded. The second input port of the first self-locking unit is connected to the emitter of the second transistor and one end of the first resistor, respectively. The other end of the first resistor is connected to the base of the first transistor. The collector of the second transistor is connected to the second output port and one end of the fourth resistor, respectively. The other end of the fourth resistor is grounded. The first input port and the second input port are used to input complementary two-way drive signals.

[0015] In one embodiment of this application, the self-locking unit further includes a second self-locking unit, which includes a third transistor, a fourth transistor, a fifth resistor, a sixth resistor, a seventh resistor, and an eighth resistor. The third input port of the second self-locking unit is connected to the emitter of the third transistor and one end of the sixth resistor, respectively. The other end of the sixth resistor is connected to the base of the fourth transistor. The collector of the third transistor is connected to the third output port and one end of the seventh resistor, respectively. The other end of the seventh resistor is grounded. The fourth input port of the second self-locking unit is connected to the emitter of the fourth transistor and one end of the fifth resistor, respectively. The other end of the fifth resistor is connected to the base of the third transistor. The collector of the fourth transistor is connected to the fourth output port and one end of the eighth resistor, respectively. The other end of the eighth resistor is grounded. The third and fourth input ports are used to input two additional complementary drive signals.

[0016] In one embodiment of this application, the power module further includes a soft-start unit and a relay. The input terminal of the soft-start unit is connected to the input module and the MCU, respectively, and its output terminal is connected to the buck-boost unit. The buck-boost unit further includes a charging capacitor. The input terminal of the relay is connected to the input module, and the control terminal of the relay is connected to the MCU so that the MCU can control its on / off state. The output terminal of the relay is connected to the first shunt. When an external power supply is connected to the input module, the MCU controls the soft-start unit to pre-charge the charging capacitor. The soft-start unit is used to prevent the instantaneous current generated when the relay is closed from causing circuit failure.

[0017] In one embodiment of this application, the soft-start unit includes a ninth resistor, a first diode, a fifth switch, a second diode, a tenth resistor, an eleventh resistor, a fifth transistor, and a twelfth resistor. The input terminal of the soft-start unit is connected to the input module, and its control terminal is connected to the MCU. The control terminal is connected to the base of the fifth transistor and one end of the twelfth resistor, respectively. The other end of the twelfth resistor is connected to the emitter of the fifth transistor. The collector of the fifth transistor is connected to one end of the eleventh resistor, and the other end of the eleventh resistor is connected to the ninth resistor, the first diode, and the fifth switch, respectively. The fifth switch is connected to the anode of the second diode, and the cathode of the second diode is connected to the tenth resistor.

[0018] In one embodiment of this application, the control module further includes a protection unit, which is connected to the drive unit, the MCU, the second operational amplifier, and the second voltage sensor. The protection unit is used to receive input signals from the second voltage sensor and the second operational amplifier and determine whether short-circuit protection needs to be generated based on the input signals. When the protection unit determines that short-circuit protection needs to be generated, it outputs a signal to control the enable terminal of the drive unit to realize short-circuit protection of the charging circuit. When the protection unit receives a reset signal from the MCU, it resets its protection state.

[0019] In one embodiment of this application, the charging circuit further includes an auxiliary power module, whose input terminal is connected to the output terminal of the input module and the output terminal of the power module, and whose output terminal is connected to the control module to provide power to the control module.

[0020] In one embodiment of this application, the input module is used to connect to a photovoltaic panel power supply, a vehicle cigarette lighter, a vehicle charging power supply, or an external DC power supply, and the positive and negative terminals of the output module are connected to the positive and negative terminals of the rechargeable battery respectively.

[0021] In one embodiment of this application, the control module further includes LED indicator lights, which are connected to the MCU and the protection unit respectively to indicate visual warnings in emergency situations.

[0022] Secondly, this application also provides a charger, the charger including the charging circuit as described in the first aspect.

[0023] Thirdly, this application also provides an energy storage terminal, which includes the charging circuit described in the first aspect.

[0024] In one embodiment of this application, the energy storage terminal further includes a rechargeable battery connected to the charging circuit.

[0025] This application provides a charging circuit that uses a control module to control a power module to boost or buck the input voltage to convert it into the charging voltage required by the rechargeable battery. This enables a wide voltage range input and high-power charging, solving the problems of input voltage and charging power limitations of dedicated control chips in the prior art.

[0026] Furthermore, by setting up a self-locking unit controlled by the MCU, it is possible to prevent the switching transistor of the buck-boost unit from being damaged due to the simultaneous conduction of the two complementary drive signals, thus ensuring the reliability of the charging circuit.

[0027] Furthermore, by setting up a soft-start unit controlled by the MCU, arcing can be prevented from occurring due to direct relay closure, thus improving the reliability of the charging circuit. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a block diagram of the charging circuit provided in this application; Figure 2 This is a module block diagram of the charging circuit provided in the embodiments of this application; Figure 3 This is a schematic diagram of the main circuit of the charging circuit provided in the embodiments of this application; Figure 3 (a) is Figure 3 The circuit diagram for the first part; Figure 3 (b) is Figure 3 The circuit diagram for the second part; Figure 3 (c) is Figure 3 The circuit diagram of the third part; Figure 3 (d) is Figure 3 Circuit diagram of the buck mode; Figure 3 (e) is Figure 3 Circuit diagram of boost mode; Figure 4 This is a circuit diagram of the relay driving circuit provided in the embodiments of this application; Figure 5 This is a circuit diagram of the first voltage sensor provided in an embodiment of this application; Figure 6 This is a circuit diagram of the first shunt and the first operational amplifier provided in an embodiment of this application; Figure 7 This is a circuit diagram of the second voltage sensor provided in an embodiment of this application; Figure 8 This is a circuit diagram of the second shunt and the second operational amplifier provided in an embodiment of this application; Figure 9 This is a circuit diagram of the self-locking unit provided in an embodiment of this application; Figure 10 This is a circuit diagram of the driving unit provided in an embodiment of this application; Figure 11 This is a circuit diagram of the protection unit provided in an embodiment of this application; Figure 12 This is a circuit diagram of the MCU provided in the embodiments of this application; Figure 13 This is a circuit diagram of the auxiliary power module provided in an embodiment of this application; Figure 14 This is a schematic diagram of the appearance of the charging device provided in the embodiments of this application; Figure 15 This is a schematic diagram of the structure of the energy storage terminal provided in the embodiments of this application. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein.

[0032] To address the limitations of input voltage and charging power in existing dedicated control chips, this application provides a charging circuit, charger, and energy storage terminal. The control module controls the power module to boost or buck the input voltage to convert it into the charging voltage required by the rechargeable battery, thereby achieving a wide voltage range input and high-power charging, thus solving the problems of input voltage and charging power limitations in existing dedicated control chips.

[0033] The following is combined with Figures 1-15 This application describes a charging circuit, a charger, and an energy storage terminal.

[0034] Please refer to Figure 1 , Figure 1 This is a block diagram of the charging circuit provided in this application. A charging circuit 100 includes an input module 110, a power module 120, a control module 130, and an output module 140. The charging circuit 100 is connected to a rechargeable battery 160, and the charging circuit 100 is used to charge the rechargeable battery 160.

[0035] The input module 110 is used to input voltage.

[0036] The power module 120 is connected to the input module 110. The power module 120 includes a buck-boost unit, which includes a boost mode and a buck mode. The power module 120 is used to convert the voltage input to the input module 110 into the voltage required by the rechargeable battery 160 through the boost mode or the buck mode.

[0037] The control module 130 is connected to the power module 120, and the control module 130 is used to control the power module 120 to perform boost or buck conversion.

[0038] The output module 140 is connected to the power module 120, and the output module 140 is used to output the voltage converted by the power module 120 to the rechargeable battery 160.

[0039] In some embodiments of this application, the charging circuit 100 may further include an auxiliary power module 150. The input terminal of the auxiliary power module 150 is connected to the output terminal of the input module 110 and the output terminal of the power module 120, respectively, and the output terminal of the auxiliary power module 150 is connected to the control module 130 to provide power to the control module 130.

[0040] For example, the input module 110 has at least one input interface for connecting to a photovoltaic panel power source, a vehicle cigarette lighter, a vehicle charging power source, or an external DC power source. The positive and negative terminals of the output module 140 are connected to the positive and negative terminals of the rechargeable battery 160, respectively.

[0041] For example, the rechargeable battery 160 can be composed of at least one battery string. Preferably, the rechargeable battery 160 can be composed of a battery string of 4 to 20 strings, which can meet the on-board charging needs of energy storage products and also support the use of photovoltaic modules with different numbers of strings.

[0042] It should be noted that the input interface of the input module 110 described in this application can also realize the function of combining the vehicle charging interface and the photovoltaic panel charging interface into one, that is, using one input interface to be compatible with vehicle charging and photovoltaic charging.

[0043] In summary, the charging circuit described in this application can overcome the limitations of input voltage and charging power of dedicated control chips. By using the charging circuit described in this application, a wide voltage range input and high-power charging can be achieved.

[0044] The charging circuit described in this application is illustrated below through an embodiment.

[0045] Please refer to Figure 2 , Figure 2 This is a block diagram of a charging circuit provided in an embodiment of this application. The charging circuit 100 provided in this embodiment includes an input module 110, a power module 120, a control module 130, an output module 140, and an auxiliary power module 150. The charging circuit 100 is connected to a rechargeable battery 150, and the charging circuit 100 is used to charge the rechargeable battery 160.

[0046] For example, the power module 120 includes a soft-start unit 121, a relay 122, a first shunt 123, a buck-boost unit 124, and a second shunt 125. The control module 130 includes a first voltage sensor 131, a first operational amplifier 132, a microcontroller unit (MCU) 133, a self-locking unit 134, a drive unit 135, a second operational amplifier 136, a second voltage sensor 137, a protection unit 138, and an LED indicator 139.

[0047] For example, the input module 110 has positive and negative input interfaces, and the positive and negative terminals of the input module 110 are connected to the positive and negative terminals of the rechargeable battery 160, such as... Figure 3As shown. The positive and negative input interfaces can be connected to a photovoltaic panel, a car cigarette lighter, or an external DC (direct current) input power supply. Connector J2 is connected to the positive terminal of the input power supply, and connector J6 is connected to the negative terminal. A fuse F2 is connected in series at the output terminal of connector J2. When an abnormal current occurs and reaches a certain level, the fuse will blow, thus cutting off the entire circuit and providing protection.

[0048] Please refer to Figure 2 , Figure 3 , Figure 3 (a) Figure 3 (b) and Figure 3 (c), where Figure 3 This is a schematic diagram of the main circuit of the charging circuit provided in the embodiments of this application. Figure 3 (a) is Figure 3 The circuit diagram of the first part, Figure 3 (b) is Figure 3 The circuit diagram for the second part, Figure 3 (c) is Figure 3 The circuit diagram for the third part. Because... Figure 3 The circuit diagram shown is quite long, so it is divided into three parts. Figure 3 (a) Figure 3 (b) and Figure 3 (c), that is Figure 3 = Figure 3 (a)+ Figure 3 (b)+ Figure 3 (c).

[0049] The input terminal of relay 122 (K1) is connected to the input module 110, the control terminal of relay 122 (K1) is connected to the MCU 133, the output terminal of relay 122 (K1) is connected to the first shunt 123, the on / off state of relay 122 (K1) is controlled by MCU 133, and the soft start unit 121 is used to prevent the instantaneous current generated when relay 122 (K1) is closed from causing circuit failure.

[0050] For example, the on / off state of relay 122 (K1) is controlled by MCU 133 through a relay drive circuit, such as... Figure 4 As shown, it mainly includes diode D7, transistor Q8, and transistor Q11. The output ports of the relay 122 (K1) coil are the +12VD port and the K1-2 port. The anode of diode D7 is connected to the K1-2 port, and the cathode of diode D7 is connected to the +12VD port. Diode D7 freewheels in reverse, providing a discharge path for the relay coil when transistor Q11 switches from conducting to turning off, and clamping its voltage at +12V.

[0051] The anode of diode D7 is connected to the collector of transistor Q11, the emitter of transistor Q11 is grounded, the base of transistor Q11 is connected to the emitter of transistor Q8, the base of transistor Q8 is connected to the control terminal CHG_K1 of relay 122 (K1) through resistor R72, and the control terminal CHG_K1 is connected to MCU133 to receive the control signal output by MCU133. The collector of transistor Q8 is connected to the +12VD port through parallel resistors R75 and R71.

[0052] For example, such as Figure 2 , Figure 3 As shown, the input terminals of the soft-start unit 121 are connected to the input module 110 and the MCU 133, respectively, and its output terminal is connected to the buck-boost unit 124. The buck-boost unit 124 includes charging capacitors, namely capacitors C5, C8, C105, and C108. Capacitors C5, C8, C105, and C108 are connected in parallel to each other in the main circuit of the power module 120. When an external power supply is connected to the input interface of the input module 110, the MCU 133 controls the soft-start unit 121 to pre-charge the charging capacitors. The soft-start unit 121 is used to prevent the instantaneous current generated when the relay KI is closed from causing circuit failure.

[0053] Specifically, such as Figure 3 As shown, the soft-start unit includes a ninth resistor R132, a first diode D26, a fifth switch Q24, a second diode D8, a tenth resistor R74, an eleventh resistor R133, a fifth transistor Q26, and a twelfth resistor R137. The input terminal of the soft-start unit is connected to the input module 110, and its control terminal SS is connected to the MCU 133. The control terminal SS is connected to the base of the fifth transistor Q26 and one end of the twelfth resistor R137. The other end of the twelfth resistor R137 is connected to the emitter of the fifth transistor Q26. The collector of the fifth transistor Q26 is connected to one end of the eleventh resistor R133. The other end of the eleventh resistor R133 is connected to the ninth resistor R132, the first diode D26, and the fifth switch Q24. The fifth switch Q24 is connected to the anode of the second diode D8, and the cathode of the second diode D8 is connected to the tenth resistor R74.

[0054] Due to the power-on time requirements and the power consumption of the internal control circuit, a certain positive voltage difference will still exist between the input power supply and the charging capacitor before the relay closes (i.e., the input voltage is higher than the charging capacitor voltage). This results in a large instantaneous inrush current when the relay closes. Such a large inrush current can easily cause the fuse to blow and damage components such as the relay at the power input terminal, leading to circuit failure. Therefore, it is necessary to pre-charge the charging capacitor using the MCU-controlled soft-start unit before the relay closes to reduce the positive voltage difference between the input power supply and the charging capacitor, thus preventing circuit failure caused by the instantaneous current generated when the relay closes.

[0055] For example, such as Figure 2 , Figure 3 As shown, the input terminal of the first voltage sensor 131 is connected to the positive and negative terminals of the input module 110 via resistors R5 and R3, respectively. Figure 3 The VIN+ and VIN- ports are the access ports of the first voltage sensor 131, and its output is connected to the MCU 133. The first voltage sensor 131 is used to detect whether the input module 110 has an external power supply.

[0056] Specifically, the circuit of the first voltage sensor 131 is as follows: Figure 5 As shown, the VIN+ and VIN- ports of the first voltage sensor 131 (U5-A) are... Figure 3 The VIN+ and VIN- ports are connected in the circuit. The VIN+ port is connected to the positive input terminal of the first voltage sensor 131 (U5-A) through resistor R83, and the VIN- port is connected to the negative input terminal of the first voltage sensor 131 (U5-A) through resistor R63.

[0057] For example, such as Figure 2 , Figure 3 As shown, the first shunt 123 is connected in series with the positive terminal of the input module 110 and connected to the first operational amplifier 132. The first operational amplifier 132 is connected to the MCU 133. When the first voltage sensor 131 detects that an external power supply is connected, the first shunt 123 converts the current signal of the external power supply input into a voltage signal and then converts it into a voltage signal within a preset range (e.g., 0-3V) through the first operational amplifier 131 to send it to the sampling terminal of the MCU 133. The sampling terminal is the ADC (Analog-to-Digital Converter) sampling terminal.

[0058] Specifically, the circuit diagrams of the first shunt 123 (U16) and the first operational amplifier 132 (U5-B) are as follows: Figure 6 As shown, Figure 6 The input PVIN port and IN / IP port are Figure 3The PVIN port and IN / IP- port are connected to the first and second pins of the first shunt 123 (U16). The IN / IP- port is connected to the third and fourth pins of the first shunt 123 (U16). The fifth pin of the first shunt 123 (U16) is grounded, the seventh pin is connected to the positive input terminal of the first operational amplifier 132 (U5-B), and the eighth pin is connected to the +3.3V port.

[0059] For example, such as Figure 3 As shown, the input terminal of the second voltage sensor 137 is connected to the positive and negative terminals of the rechargeable battery 160 via resistors R10 and R11, respectively. Figure 3 The Vo+ and Vo- ports are the access ports of the second voltage sensor 137, and its output is connected to the MCU 133. The second voltage sensor 137 is used to detect whether the charging circuit described in this application is connected to the rechargeable battery 160.

[0060] Specifically, the circuit of the second voltage sensor 137 is as follows: Figure 7 As shown, the Vo+ and Vo- ports of the second voltage sensor 137 (U18-A) are... Figure 3 The Vo+ and Vo- ports are connected in the circuit. The Vo+ port is connected to the positive input terminal of the second voltage sensor 137 (U18-A) through resistor R65, and the Vo- port is connected to the negative input terminal of the second voltage sensor 137 (U18-A) through resistor R66.

[0061] For example, such as Figure 2 , Figure 3 As shown, the second shunt 125 is connected in series with the positive terminal of the rechargeable battery 160 and connected to the second operational amplifier 136. The second operational amplifier 136 is connected to the MCU 133. When the second voltage sensor 137 detects that the charging circuit described in this application is connected to the rechargeable battery 160, the second shunt 125 converts the current signal of the rechargeable battery 160 into a voltage signal, and then the second operational amplifier 136 converts it into a voltage signal within a preset range (e.g., 0-3V) to be sent to the ADC sampling terminal of the MCU 133.

[0062] Specifically, the circuit diagrams of the second shunt 125 (U17) and the second operational amplifier 136 (U18-B) are as follows: Figure 8 As shown, Figure 8 The input ports BAT / IP+ and BAT+ are... Figure 3The BAT / IP+ and IN / IP- ports are connected to the input terminals of the second shunt 125 (U17). One output terminal of the second shunt 125 (U17) is connected to the positive input terminal of the second operational amplifier 136 (U18-B), and the other output terminal is connected to the +3.3V port.

[0063] For example, such as Figure 2 , Figure 3 , Figure 3 (d) and Figure 3 As shown in (e), the buck-boost unit 124 includes a buck mode 1241 and a boost mode 1242. The buck-boost unit 124 includes a first switch Q3, a second switch Q7, a third switch Q16, a fourth switch Q9, an energy storage inductor L3, and input filter capacitors C1 and C128. The energy storage inductor L3 is connected to the first switch Q3, the second switch Q7, the third switch Q16, and the fourth switch Q9. The buck-boost unit 124 stores and releases energy through the energy storage inductor L3 to achieve charging and discharging. Charging the energy storage inductor L3 achieves the buck mode, and discharging the energy storage inductor L3 achieves the boost mode. The voltage output is controlled by the first switch Q3, the second switch Q7, the third switch Q16, and the fourth switch Q9.

[0064] The buck-boost unit 124 converts the voltage input from the external power supply into the voltage required by the rechargeable battery 160. The MCU determines whether to switch to boost mode 1242 or buck mode 1241 by comparing the voltage input from the external power supply and the voltage of the rechargeable battery 160, thereby implementing the buck-boost function for a wide voltage range input voltage according to the voltage required by the rechargeable battery 160. That is, when the input voltage is lower than the voltage of the rechargeable battery 160, the buck-boost unit 124 operates in boost mode 1242 (e.g., ...). Figure 3 (e) As shown, when the input voltage is higher than the voltage of the rechargeable battery 160, the buck-boost unit 124 operates in buck mode 1241 (as shown). Figure 3 (d) is shown.

[0065] Specifically, each switching transistor (Q3, Q7, Q9, Q16) corresponds to one drive signal, such as... Figure 3As shown, the L / TOP port is connected to the input of switch Q7 via resistor R93, the L / BOT port is connected to the input of switch Q3 via resistors R94 and R265, the R / TOP port is connected to the input of switch Q16 via resistor R99, and the R / BOT port is connected in series with resistor R180 and then connected to the cathode of diode D39. The anode of diode D39 is connected to the input of switch Q9. The L / TOP, L / BOT, R / TOP, and R / BOT ports are four complementary drive signals output by the MCU133, with L / TOP and L / BOT being two complementary drive signals, and R / TOP and R / BOT being two other complementary drive signals.

[0066] When the buck-boost unit 124 operates in boost mode 1242, the first switch Q3 and the second switch Q7 operate in the switching state, while the third switch Q9 and the fourth switch Q16 operate in the boost conversion state. When the buck-boost unit 124 operates in buck mode 1241, the third switch Q9 and the fourth switch Q16 operate in the switching state, while the first switch Q3 and the second switch Q7 operate in the buck conversion state.

[0067] It should be noted that the aforementioned switching transistors Q3, Q7, Q9, and Q16 can all be MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) or IGBTs (Insulated Gate Bipolar Transistors). In some embodiments of this application, switching transistors Q3 and Q16 can be replaced with diodes, but an additional power supply is required for the drive circuit to power the switching transistor Q3.

[0068] For example, such as Figure 2 As shown, the self-locking unit 134 is connected to the MCU 133. The self-locking unit 134 is used to protect the four complementary drive signals output by the MCU 133 to prevent the two complementary drive signals output by the MCU from being simultaneously turned on or off when the charging circuit described in this application is powered on or off.

[0069] Specifically, the circuit of the self-locking unit 134 is as follows: Figure 9As shown, the self-locking unit includes a first self-locking unit and a second self-locking unit. The first input port of the first self-locking unit receives the L / TOP_PWM drive signal, and the second input port receives the L / BOT_PWM drive signal. The third input port of the second self-locking unit receives the R / TOP_PWM drive signal, and the fourth input port receives the R / BOT_PWM drive signal. L / TOP_PWM and L / BOT_PWM are complementary drive signals, and R / TOP_PWM and R / BOT_PWM are another complementary drive signal.

[0070] The first self-locking unit includes a first transistor Q2, a second transistor Q28, a first resistor R199, a second resistor R208, a third resistor R82, and a fourth resistor R92. The first input port L / TOP_PWM of the first self-locking unit is connected to the emitter of the first transistor Q2 and one end of the second resistor R208. The other end of the second resistor R208 is connected to the base of the second transistor Q28. The collector of the first transistor Q2 is connected to the first output port L / TOP_PWM_P and one end of the third resistor R82. The other end is grounded; the second input port L / BOT_PWM of the first self-locking unit is connected to the emitter of the second transistor Q28 and one end of the first resistor R199, respectively. The other end of the first resistor R199 is connected to the base of the first transistor Q2. The collector of the second transistor Q28 is connected to the second output port L / BOT_PWM_P and one end of the fourth resistor R92, respectively. The other end of the fourth resistor R92 is grounded; the first input port L / TOP_PWM and the second input port L / BOT_PWM are used to input complementary two-way drive signals.

[0071] The second self-locking unit includes a third transistor Q32, a fourth transistor Q33, a fifth resistor R209, a sixth resistor R212, a seventh resistor R196, and an eighth resistor R198. The third input port R / TOP_PWM of the second self-locking unit is connected to the emitter of the third transistor Q32 and one end of the sixth resistor R212. The other end of the sixth resistor R212 is connected to the base of the fourth transistor Q33. The collector of the third transistor Q32 is connected to the third output port R / TOP_PWM_P and one end of the seventh resistor R196. The seventh resistor R198... The other end of 6 is grounded; the fourth input port R / BOT_PWM of the second self-locking unit is connected to the emitter of the fourth transistor Q33 and one end of the fifth resistor R209, respectively. The other end of the fifth resistor R209 is connected to the base of the third transistor Q32. The collector of the fourth transistor Q33 is connected to the fourth output port R / BOT_PWM_P and one end of the eighth resistor R198, respectively. The other end of the eighth resistor R198 is grounded; the third input port R / TOP_PWM and the fourth input port R / BOT_PWM are used to input two other complementary drive signals.

[0072] Therefore, when the L / TOP_PWM drive signal received at the first input port is high, the L / BOT_PWM drive signal received at the second input port is low. The high level turns on the first transistor Q2, and the low level turns off the second transistor Q28. Thus, L / TOP_PWM_P can only be output through the first output port. This prevents the two complementary drive signals (L / TOP_PWM and L / BOT_PWM) from conducting simultaneously; "complementary" means one is high and the other is low. The principle is similar for the other two complementary drive signals (R / TOP_PWM and R / BOT_PWM).

[0073] For example, such as Figure 2 As shown, the drive unit 135 receives the input from the self-locking unit 134. The four drive signals output are L / TOP_PWM_P, L / BOT_PWM_P, R / TOP_PWM_P, and R / BOT_PWM_P. The drive unit 135 amplifies these four drive signals to improve their startup capability, thereby driving the switching transistors (Q3, Q7, Q9, Q16) of the buck-boost unit 124 to turn on and off.

[0074] Specifically, the circuit of the drive unit 135 is as follows: Figure 10As shown. The L / TOP_PWM_P port is connected to pin 12 (HIN) of driver chip U8, and the L / BOT_PWM_P port is connected to pin 14 (LIN) of driver chip U8. The R / TOP_PWM_P port is connected to pin 12 (HIN) of driver chip U7, and the R / BOT_PWM_P port is connected to pin 14 (LIN) of driver chip U7. Figure 10 The output L / TOP and L / BOT ports of the driver chip U8, and the output R / TOP and R / BOT ports of the driver chip U7, are connected to... Figure 3 The L / TOP port, L / BOT port, R / TOP port, and R / BOT port are connected.

[0075] It should be noted that the driver chips U7 and U8 of the driver unit 135 are both half-bridge driver chips, but these driver chips can also be replaced by driver optocouplers. For example, four TLP250 or TLP350 chips can be used for isolated driving.

[0076] For example, such as Figure 2 As shown, the protection unit 138 is connected to the drive unit 135, the MCU 133, the second operational amplifier 136, and the second voltage sensor 137. The protection unit 138 is used to receive the input signals from the second voltage sensor 137 and the second operational amplifier 136, and outputs a signal to control the enable terminal of the drive unit 135 when it determines that protection is required based on the input signals. When the protection unit 138 receives a reset signal from the MCU 133, it clears its protection state.

[0077] Specifically, the circuit of protection unit 138 is as follows: Figure 11 As shown. The protection unit 138 receives the input signals from the second voltage sensor 137 and the second operational amplifier 136, and then outputs a signal to control the enable terminal SD of the drive unit 135. At the same time, it is connected to the input terminal OC of the MCU 133. After protection occurs, the MCU 133 needs to send a pulse signal to the OCR port to clear the protection state.

[0078] For example, such as Figure 2 As shown, the control module 130 also includes an LED indicator 139. The MCU 133 is connected to the OC port of the protection unit 138 through the LED indicator 139 to indicate a visual warning in an emergency.

[0079] For example, such as Figure 2As shown, MCU133 receives input signals from the first voltage sensor 131, the first operational amplifier 132, the second voltage sensor 137, and the second operational amplifier 136, and provides drive signals to relay 122 to control the on and off of relay 122. Simultaneously, MCU133 outputs drive signals required by buck-boost unit 124 to self-locking unit 134 to control the on and off of the switching transistor of buck-boost unit 124 via drive unit 135, thereby achieving boost mode or buck mode.

[0080] In addition, the MCU133 synchronously receives the input signal of the protection unit 138. When the protection unit 138 detects that the protection mechanism has been activated, it will continuously determine whether the protection mechanism has been deactivated. After the mechanism is deactivated, the MCU133 provides a reset signal to the protection unit 138 to reset its protection state.

[0081] Specifically, the circuit of MCU133 is as follows: Figure 12 As shown. The OCR port of U21 (MCU133) is connected to the OCR port of protection unit 138 to send a reset signal to protection unit 138. U21 outputs four drive signals: L / TOP_PWM, R / BOT_PWM, L / BOT_PWM, and R / TOP_PWM. The CHG_K1 port is connected to the CHG_K1 port of relay 122, providing drive signals to relay 122 through the CHG_K1 port to control the on and off of relay 122. Protection unit 138 is connected to the input terminal OC of U21 to receive input signals from protection unit 138.

[0082] For example, such as Figure 2 As shown, the charging circuit described in this application also includes an auxiliary power module 150. The input terminal of the auxiliary power module 150 is connected to the output terminal of the input module 110 and the output terminal of the power module 120, respectively. The output terminal of the auxiliary power module 150 is connected to the control module 130 to provide power to the control module 130.

[0083] Specifically, the circuit of the auxiliary power supply module 150 is as follows: Figure 13 As shown, the input power supply PV+ of the input module 110 and the output voltage BAT+ of the buck-boost unit 124 are connected to the output of the auxiliary power module 150. The auxiliary power module 150 provides the required operating voltage to the control module 130 through voltage conversion, such as providing the control module 130 with operating voltages of +12VD, +5V, and +3.3V.

[0084] It should be noted that, Figure 13 The flyback circuit used in the auxiliary power module 150 shown can be replaced by a non-isolated DC-DC step-down chip.

[0085] For example, such as Figure 2 , Figure 3 As shown, the output module 140 is connected to the power module 120. The output module 140 is used to output the voltage converted by the buck-boost unit 124 of the power module 120 to the rechargeable battery 160 to achieve high-power charging. Connectors J8 and J9 of the output module 140 are connected to the positive and negative terminals of the rechargeable battery 160 respectively.

[0086] In summary, this application achieves a wide voltage range input by automatically switching between boost and buck modes, and also realizes the functions of traditional car chargers and photovoltaic chargers, thereby breaking through the limitations of traditional integrated chips and realizing high voltage input and high power charging.

[0087] Furthermore, the charging circuit described in this application, by incorporating a self-locking unit controlled by an MCU, prevents damage to the switching transistor caused by simultaneous conduction of the drive, thus ensuring the reliability of the charger. Moreover, by setting up a first voltage sensor, a first shunt, a first operational amplifier, a second voltage sensor, a second shunt, and a second operational amplifier, the voltage and current of the external power supply input and the voltage and current of the rechargeable battery are monitored respectively, and the voltage and current of the rechargeable battery are used as inputs to the protection unit to achieve short-circuit protection for the rechargeable battery.

[0088] Furthermore, the charging circuit described in this application is equipped with a soft-start unit, which can prevent arcing caused by direct relay closure and improve reliability.

[0089] Please see Figure 14 , Figure 14 This is a schematic diagram of the appearance of a charger provided in an embodiment of this application. This application also describes a charger, which includes a charger body 1410, a DC input interface 1420, and a DC output interface 1430. The charger body 1410 includes the charging circuit 100 described in this application.

[0090] Please refer to Figure 15 , Figure 15 This is a schematic diagram of the structure of the energy storage terminal provided in this application. This application also provides an energy storage terminal 1500, which includes the charging circuit 100 and the rechargeable battery 160 described in this application. The rechargeable battery uses at least one battery pack, for example, a battery pack with 4-20 strings, which can meet the vehicle charging needs of the energy storage terminal and support the use of photovoltaic modules with different numbers of strings.

[0091] It should be noted that the charger and energy storage terminal provided in this application embodiment can achieve the functions of the charging circuit embodiment described above and can achieve the same technical effects. Therefore, the parts that are the same as those in the charging circuit embodiment and the beneficial effects will not be described in detail here.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A charging circuit, characterized in that, The charging circuit includes: Input module, used for input voltage; A power module, connected to the input module, includes a buck-boost unit, a soft-start unit, a relay, and a first shunt. The buck-boost unit includes a boost mode and a buck mode, used to convert the voltage input to the input module into the voltage required by the rechargeable battery through the boost mode or the buck mode. A control module, connected to the power module, is used to control the power module to perform boost or buck conversion; the control module includes an MCU. An output module, connected to the power module, is used to output the voltage converted by the power module to the rechargeable battery; The soft-start unit has its input terminals connected to the input module and the MCU, and its output terminal connected to the buck-boost unit, which includes a charging capacitor. The relay's input terminal is connected to the input module, and its control terminal is connected to the MCU for on / off control. The relay's output terminal is connected to the buck-boost unit via the first shunt. When an external power source is connected to the input module, the MCU controls the soft-start unit to pre-charge the charging capacitor to prevent circuit malfunctions caused by the instantaneous current generated when the relay is closed. The control module also includes a drive unit. The MCU outputs the drive signal required by the buck-boost unit through the drive unit, and controls the buck-boost unit to achieve boost mode or buck mode through the drive unit. The buck-boost unit further includes an energy storage inductor (L3) and first to fourth switching transistors respectively connected to the energy storage inductor (L3). Each switching transistor is connected to the drive unit and corresponds to one drive signal output by the drive unit. The drive signals corresponding to the first and second switching transistors are two complementary drive signals, and the drive signals corresponding to the third and fourth switching transistors are two other complementary drive signals. When the buck-boost unit operates in boost mode, the first and second switching transistors operate in the switching state, and the third and fourth switching transistors operate in the boost conversion state. When the buck-boost unit operates in buck mode, the third and fourth switching transistors operate in the switching state, and the first and second switching transistors operate in the buck conversion state.

2. The charging circuit according to claim 1, characterized in that, The MCU is used to output a drive signal to the buck-boost unit to achieve boost mode or buck mode. When the MCU compares the voltage input through the input module to be lower than the voltage of the rechargeable battery, it controls the buck-boost unit to switch to boost mode. When the MCU compares the voltage input through the input module to be higher than the voltage of the rechargeable battery, it controls the buck-boost unit to switch to buck mode.

3. The charging circuit according to claim 2, characterized in that, The control module further includes a first voltage sensor, the input terminal of which is connected to the positive and negative terminals of the input module respectively, and its output terminal is connected to the MCU. The first voltage sensor is used to detect whether the input module has an external power supply.

4. The charging circuit according to claim 3, characterized in that, The control module further includes a first operational amplifier, which is connected to the MCU. The first shunt converts the current signal input from the external power supply into a voltage signal, which is then converted by the first operational amplifier into a voltage signal within a preset range and sent to the sampling terminal of the MCU.

5. The charging circuit according to claim 1, characterized in that, The control module also includes a second voltage sensor. The input terminal of the second voltage sensor is connected to the positive and negative terminals of the rechargeable battery, respectively, and its output terminal is connected to the MCU. The second voltage sensor is used to detect whether the charging circuit is connected to the rechargeable battery.

6. The charging circuit according to claim 5, characterized in that, The power module further includes a second shunt, and the control module further includes a second operational amplifier. The buck-boost unit is connected to the output module through the second shunt, and the second operational amplifier is connected to the MCU. The second shunt converts the current signal of the charging battery into a voltage signal, and then the second operational amplifier converts it into a voltage signal within a preset range to be sent to the sampling terminal of the MCU.

7. The charging circuit according to claim 1, characterized in that, The control module also includes a self-locking unit, which is connected to the MCU and the drive unit respectively. The self-locking unit is used to prevent the two complementary drive signals output by the MCU from being simultaneously turned on when the charging circuit is powered on or off.

8. The charging circuit according to claim 7, characterized in that, The self-locking unit includes a first self-locking unit, which comprises a first transistor (Q2), a second transistor (Q28), a first resistor (R199), a second resistor (R208), a third resistor (R82), and a fourth resistor (R92). The first input port (L / TOP_PWM) of the first self-locking unit is connected to the emitter of the first transistor (Q2) and one end of the second resistor (R208). The other end of the second resistor (R208) is connected to the base of the second transistor (Q28). The collector of the first transistor (Q2) is connected to the first output port (L / TOP_PWM_P) and one end of the third resistor (R82). The first self-locking unit's second input port (L / BOT_PWM) is connected to the emitter of the second transistor (Q28) and one end of the first resistor (R199), respectively. The other end of the first resistor (R199) is connected to the base of the first transistor (Q2). The collector of the second transistor (Q28) is connected to the second output port (L / BOT_PWM_P) and one end of the fourth resistor (R92), respectively. The other end of the fourth resistor (R92) is grounded. The first input port (L / TOP_PWM) and the second input port (L / BOT_PWM) are used to input complementary two-way drive signals.

9. The charging circuit according to claim 8, characterized in that, The self-locking unit further includes a second self-locking unit, which comprises a third transistor (Q32), a fourth transistor (Q33), a fifth resistor (R209), a sixth resistor (R212), a seventh resistor (R196), and an eighth resistor (R198). The third input port (R / TOP_PWM) of the second self-locking unit is connected to the emitter of the third transistor (Q32) and one end of the sixth resistor (R212), respectively. The other end of the sixth resistor (R212) is connected to the base of the fourth transistor (Q33). The collector of the third transistor (Q32) is connected to the third output port (R / TOP_PWM_P) and one end of the seventh resistor (R196), respectively. The first terminal is connected to the ground, and the other end of the seventh resistor (R196) is grounded; the fourth input port (R / BOT_PWM) of the second self-locking unit is connected to the emitter of the fourth transistor (Q33) and one end of the fifth resistor (R209), respectively. The other end of the fifth resistor (R209) is connected to the base of the third transistor (Q32). The collector of the fourth transistor (Q33) is connected to the fourth output port (R / BOT_PWM_P) and one end of the eighth resistor (R198), respectively. The other end of the eighth resistor (R198) is grounded; the third input port (R / TOP_PWM) and the fourth input port (R / BOT_PWM) are used to input two other complementary drive signals.

10. The charging circuit according to claim 9, characterized in that, The soft-start unit includes a ninth resistor (R132), a first diode (D26), a fifth switching transistor (Q24), a second diode (D8), a tenth resistor (R74), an eleventh resistor (R133), a fifth transistor (Q26), and a twelfth resistor (R137). The input terminal of the soft-start unit is connected to the input module, and its control terminal (SS) is connected to the MCU. The control terminal (SS) is connected to the base of the fifth transistor (Q26) and one end of the twelfth resistor (R137). The other end of the twelfth resistor (R137) is connected to the emitter of the fifth transistor (Q26). The collector of the fifth transistor (Q26) is connected to the eleventh resistor. One end of the eleventh resistor (R133) is connected to the first resistor (R132), and the other end of the eleventh resistor (R133) is connected to one end of the ninth resistor (R132), the anode of the first diode (D26), and the gate of the fifth switch (Q24). The source of the fifth switch (Q24) is connected to the other end of the ninth resistor (R132), the cathode of the first diode (D26), and the input module. The drain of the fifth switch (Q24) is connected to the anode of the second diode (D8), and the cathode of the second diode (D8) is connected to one end of the tenth resistor (R74). The other end of the tenth resistor (R74) is connected to the first shunt.

11. The charging circuit according to claim 6, characterized in that, The control module further includes a protection unit, which is connected to the drive unit, the MCU, the second operational amplifier, and the second voltage sensor. The protection unit receives input signals from the second voltage sensor and the second operational amplifier and determines whether short-circuit protection is required based on the input signals. When the protection unit determines that short-circuit protection is required, it outputs a signal to control the enable terminal of the drive unit to achieve short-circuit protection of the charging circuit. When the protection unit receives a reset signal from the MCU, it resets its protection state.

12. The charging circuit according to claim 1, characterized in that, The charging circuit also includes an auxiliary power module, whose input terminal is connected to the output terminal of the input module and the output terminal of the power module, and whose output terminal is connected to the control module to provide power to the control module.

13. The charging circuit according to claim 1, characterized in that, The input module is used to connect to a photovoltaic panel power supply, a vehicle cigarette lighter, a vehicle charging power supply, or an external DC power supply, and the positive and negative terminals of the output module are connected to the positive and negative terminals of the rechargeable battery respectively.

14. The charging circuit according to claim 11, characterized in that, The control module also includes LED indicators, which are connected to the MCU and the protection unit respectively to indicate visual warnings in emergency situations.

15. A charger, characterized in that, The charger includes the charging circuit as described in any one of claims 1 to 14.

16. An energy storage terminal, characterized in that, The energy storage terminal includes a charging circuit as described in any one of claims 1 to 14.

17. The energy storage terminal according to claim 16, characterized in that, The energy storage terminal also includes a rechargeable battery connected to the charging circuit.

Images