TWI677164B - AC signal power conversion system, charging system and method for battery charging - Google Patents

Abstract

The invention provides an AC signal power conversion system, a charging system and a method for battery charging. The AC signal power conversion system includes: a mains rectification filter circuit that receives an AC power signal and rectifies and filters the received AC power signal; a power conversion circuit that power converts the power from the mains rectification filter circuit Receiving a rectified and filtered electric signal, and performing power conversion on the received electric signal; and outputting a rectifying filter circuit that receives the power-converted electric signal from the power conversion circuit, and Performing rectification and filtering to obtain a direct current signal for charging the battery; and a constant voltage and constant current binning circuit that receives a current level instruction from the outside of the AC signal power conversion system, and according to the current level The stage command controls the power conversion circuit to achieve stepped constant current charging of the battery.

Description

AC signal power conversion system, charging system and method for battery charging

The present invention relates generally to the field of circuits, and more particularly, to an AC signal power conversion system, a charging system, and a method for battery charging.

Lithium batteries are an indispensable part of all kinds of portable devices in today's society. They are widely used in mobile phones, notebooks, tablet computers, drones, and sweepers. Lithium batteries are rechargeable batteries with a limited number of recharges, and need to be used with corresponding chargers. Because different lithium batteries have different battery characteristics, the way the charger charges them must match the characteristics of the battery, otherwise the life and capacity of the battery will be affected.

Due to cost or design reasons, there are various charging methods for chargers, and different charging methods have different requirements for the charger's circuit. However, traditional chargers include at least AC-DC constant voltage converters, DC-DC constant current converters, and voltage sensing and controllers, which also complicates the structure of traditional chargers. And bulk. Therefore, there is a need to design a small-sized charger suitable for carrying.

According to an aspect of the present invention, there is provided an AC signal power conversion system for battery charging. The AC signal power conversion system includes: a mains rectification filter circuit that receives an alternating current signal, and Electric signals are rectified and filtered; a power conversion circuit that receives the rectified and filtered electric signals from the mains rectification and filtering circuit and performs power conversion on the received electric signals; an output rectification and filtering circuit that outputs the rectified and filtered circuit Receiving a power-converted electric signal from a power conversion circuit, rectifying and filtering the received electric signal to obtain a direct-current signal for directly charging a battery; and a constant-voltage constant-current binning circuit, the constant-voltage and constant-current binning The circuit receives the current level instruction from the outside of the AC signal power conversion system, and controls the power conversion circuit to implement the current level instruction according to the current level instruction. Charges the battery in stepped constant current.

According to another aspect of the present invention, there is provided a charging system for charging a battery, the charging system including: the AC signal power conversion system described above; and a voltage detection and control circuit, the voltage detection and control circuit Each cell in the plurality of cells performs instant detection to obtain the instant voltage of each cell, and generates and outputs a current level instruction based on a predetermined charging model and the instant voltage; wherein, the constant in the AC signal power conversion system The voltage-constant current stage circuit performs stage-constant current control on a DC signal by controlling the current input to the power conversion circuit.

According to another aspect of the present invention, a method for charging a battery is provided. The method includes: receiving an alternating current signal through a mains rectification filter circuit and rectifying and filtering the received alternating current signal; The rectification and filtering circuit receives the rectified and filtered electrical signal and performs power conversion on the received electrical signal; receives the power-converted electrical signal from the power conversion circuit through the output rectification and filtering circuit, and rectifies and filters the received electrical signal To obtain a direct current signal used to charge the battery; and to receive a current level instruction from the outside of the AC signal power conversion system through a constant voltage and constant current binning circuit, and to control the power conversion circuit according to the current level instruction to realize the battery Step-by-step constant current charging.

The AC signal power conversion system, charging system and method for battery charging provided by the embodiments of the present invention can not only realize constant voltage and constant current step-by-step control of charging, but also have a simple structure and low cost. In addition, the AC signal power conversion system and charging system provided in the embodiments of the present invention can be used to charge a battery by connecting a plurality of cells in series.

100, 200‧‧‧ Charging System

120‧‧‧AC signal power conversion system

B1, B2, B3‧‧‧ batteries

U3A‧‧‧Light Emitting Diode

104, 204‧‧‧ voltage sensing and control circuits

105, 205‧‧‧ signal isolation circuit

101, 201‧‧‧ mains rectifier filter circuit

102, 202‧‧‧ Power Conversion Circuit

103, 203‧‧‧ output rectification filter circuit

106, 206‧‧‧constant voltage and constant current stage circuit

110, 210‧‧‧ batteries

DB1‧‧‧Rectifier circuit

C1, C2‧‧‧ capacitors

S301, S302, S303, S304 ‧‧‧ steps

R6, R7, R8, R9, R10, R11‧‧‧ resistance

17, 18, 19, 20, CS, GATE, ADJ‧‧‧ pins

U3B‧‧‧Phototransistor

U1‧‧‧control chip

R1‧‧‧first resistor

300‧‧‧ How to charge the battery

Q1‧‧‧Switch circuit

T1‧‧‧Transformer circuit

D1‧‧‧rectified diode

U2‧‧‧Chip

2041‧‧‧Battery voltage sampling circuit

The present invention can be better understood according to the description of the embodiments of the present invention with reference to the following drawings, wherein: FIG. 1 shows a block diagram of a charging system for battery charging according to an embodiment of the present invention.

FIG. 2 illustrates a predetermined charging model according to an embodiment of the present invention.

FIG. 3 illustrates a current level instruction according to an embodiment of the present invention.

FIG. 4 illustrates a current level instruction according to another embodiment of the present invention.

FIG. 5 shows a schematic diagram of a charging system for battery charging according to another embodiment of the present invention.

FIG. 6 shows a flowchart of a method for charging a battery according to an embodiment of the present invention.

Features and exemplary embodiments of various aspects of the invention will be described in detail below. The following description covers many specific details in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without requiring some of these specific details. The following description of the embodiments is merely for providing a clearer understanding of the present invention by showing examples of the present invention. The present invention is by no means limited to any specific configuration proposed below, but covers any modification, replacement, and improvement of related elements or components without departing from the spirit of the present invention.

Batteries usually have one or more cells. For example, some portable devices (such as drones) often require multiple cells in series to form a battery due to the high operating voltage. Unless otherwise specified, the present application is applicable to a battery having one battery cell or a battery having one or more battery cells.

FIG. 1 shows a block diagram of a charging system for battery charging according to an embodiment of the present invention. As shown in FIG. 1, the charging system 100 includes an AC signal power conversion system 120 and a voltage sensing and control circuit 104.

In one embodiment, the charging system 100 may further include a signal isolation circuit 105, which is located between the AC signal power conversion system 120 and the voltage sensing and control circuit 104.

The AC signal power conversion system 120 may include a mains rectification filter circuit 101, a power conversion circuit 102, an output rectification filter circuit 103, and a constant voltage and constant current binning circuit 106. The transmission direction of the signal in the charging system 100 is shown by the arrow direction in FIG. 1.

The mains rectifying and filtering circuit 101 may receive an alternating current signal, and rectify and filter the received alternating current signal.

The power conversion circuit 102 may receive the rectified and filtered electric signal from the mains rectification filter circuit 101 and perform power conversion on the received electric signal.

The output rectification filter circuit 103 can receive the power from the power conversion circuit 102 The rate-converted electrical signal is used to rectify and filter the received electrical signal to obtain a direct-current electrical signal that is directly used to charge the battery 110 without further converting the current.

The voltage sensing and control circuit 104 performs instant detection on each of the one or more cells in the battery 110 to obtain an instant voltage of each cell, and based on a predetermined charging model and the detected instant voltage, Generate and output current level instructions.

The constant voltage and constant current binning circuit 106 (for example, via the signal isolation circuit 105) receives a current bin command from the voltage sensing and control circuit 104, and controls the power conversion circuit according to the current bin command to achieve the binning constant of the battery. Stream charging. Specifically, the constant-voltage and constant-current binning circuit 106 performs step-by-step constant-current control on the DC electric signal for charging the battery 110 by controlling the current input to the power conversion circuit 102.

In other words, there is no need for a conventional DC-DC constant current converter between the AC signal power conversion system 120 and the battery 110, and the electric signal output by the output rectification filter circuit 103 in the AC signal power conversion system 120 can be used as a direct battery DC signal for charging. The constant current and / or binning function of the conventional DC-DC constant current converter is performed by the constant voltage and constant current binning circuit 106 in cooperation with the signal isolation circuit 105, the voltage sensing and control circuit 104, and the power conversion circuit 102.

FIG. 2 illustrates a predetermined charging model according to an embodiment of the present invention. Different batteries have different characteristics. Figure 2 shows a predetermined charging model for a lithium battery.

After the battery cell of the lithium battery is overcharged to a voltage higher than a predetermined voltage value, side effects will begin to occur. The higher the overcharge voltage, the higher the danger. This is because during the overcharge process, materials such as the electrolyte will crack to produce gas, which will cause the battery case or pressure valve to swell and rupture, allowing oxygen to enter and react with lithium atoms accumulated on the surface of the anode, and then explode. Therefore, when charging a lithium battery, the upper limit of the voltage must be set so that the battery life, capacity, and safety can be taken into account at the same time. For this lithium battery, the optimal charging voltage upper limit is 4.2V. As shown in Figure 2, the minimum voltage of this cell is 2.4V. According to the predetermined charging model, the charging process of the battery passes through a constant current charging process and a constant voltage charging process.

Since the minimum and maximum voltages of a particular battery are known, the voltage detection and control circuit 104 can determine the The number of charged cells.

In one embodiment, the constant voltage and constant current binning circuit 106 may have multiple voltage references, so as to be able to output corresponding multiple currents, so as to implement the binning constant current control of the DC signal.

In one embodiment, the current level instruction may include a pulse width modulated signal. For example, FIG. 3 illustrates a current level instruction according to an embodiment of the present invention. FIG. 4 illustrates a current level instruction according to another embodiment of the present invention. However, the specific type of the current level instruction is not limited to the embodiment of the present invention.

In one embodiment, the current stage instruction includes a current upshift instruction and a current downshift instruction. For example, the current level command shown in FIG. 3 may be a current upshift command, and the current level command shown in FIG. 4 may be a current downshift command. The current upshift instruction and the current downshift instruction may adopt a special encoding method to prevent malfunction, but are not limited to the examples shown in the present invention.

In one embodiment, the charging system 100 may further include a charging switch circuit (not shown in the figure). The first terminal of the charging switch circuit is connected to the output terminal of the output rectification filter circuit 103, and the second terminal of the charging switch circuit is connected to the battery 110, that is, the charging switch circuit is between the output rectification filter circuit 103 and the battery 110 Used as a switch for charging the battery 110. Moreover, the third terminal of the charging switch circuit is connected to the voltage detection and control circuit 104. When the voltage sensing and control circuit 104 senses that the voltage of any one of the one or more cells of the battery 110 is within a predetermined range, the charging switch circuit is turned on to charge the cell.

The voltage sensing and control circuit 104, the signal isolation circuit 105, and the constant voltage and constant current step-up circuit 106 may constitute an isolated flyback converter, which has the voltage sensing and control circuit 104, the signal isolation circuit 105, and the constant voltage converter. The function of the constant voltage binning circuit 106.

FIG. 5 shows a schematic diagram of a charging system for battery charging according to another embodiment of the present invention. As shown in FIG. 5, the charging system 200 includes: a mains rectification filter circuit 201, a power conversion circuit 202, an output rectification filter circuit 203, a voltage sensing and control circuit 204, a signal isolation circuit 205, and a constant voltage and constant current stage circuit. 206. The function of the above circuit is the same as the function of the circuit described with reference to FIG. 1, and is not repeated here.

In one embodiment, as shown in FIG. 5, the mains rectification filter circuit 201 It may include a rectifier circuit DB1 composed of four diodes and a filter circuit composed of a capacitor C1, which are respectively used for rectifying and filtering the alternating current signal.

In one embodiment, as shown in FIG. 5, the power conversion circuit 202 may include a switching circuit Q1 and a transformer circuit T1. In one embodiment, the switching circuit Q1 may be a field effect transistor, the gate of Q1 is connected to the first terminal of the power conversion circuit 202, and the source of Q1 is connected to the second terminal of the power conversion circuit 202. However, the switching circuit Q1 is not limited to the example shown in FIG. 5.

In one embodiment, as shown in FIG. 5, the output rectification and filtering circuit 203 may include a rectification diode D1 and a capacitor C2 for rectification and filtering, respectively.

In one embodiment, as shown in FIG. 5, the voltage sensing and control circuit 204 may include a chip U2 and a battery voltage sampling circuit 2041. The battery voltage sampling circuit 2041 may be composed of resistors R6, R7, R8, R9, R10, and R11, and the connection method is shown in FIG. 5. The battery 210 shown in FIG. 5 includes three battery cells B1, B2, and B3. The number of cells connected in series is not limited to that shown in FIG. 5, and the embodiment of the present invention is not limited in this respect.

In one embodiment, the wafer may be a microcontroller U2 (the MCU), which may include a central processing unit (C entral P rocessing U nit, CPU, random access memory (R andom Access Memory, RAM having a data processing capability ), read only memory (R ead- O nly M emory, ROM), various I / O ports and interrupt system, timer / counter, the PWM circuit, analog multiplexer, A / D converter One or more of them. As shown in FIG. 5, the voltage sampling of the three cells B1, B2, and B3 is performed by the battery voltage sampling circuit 2041, and the chip U2 receives the samples through pins 17, 18, and 19 The chip U2 can also include other pins for other functions.

In one embodiment, as shown in FIG. 5, the signal isolation circuit 205 may be an optocoupler isolation circuit packaged by a light emitting diode U3A and a phototransistor U3B. The optocoupler isolation circuit makes there is no direct electrical connection between the two isolated circuits, mainly to prevent safety problems caused by the electrical connection. For example, the signal isolation circuit 205 is used to prevent safe isolation between its left high-voltage circuit and its right low-voltage circuit.

In an embodiment, as shown in FIG. 5, the first terminal of the constant-voltage constant-current step-by-step circuit 206 is connected to the first terminal of the power conversion circuit 202, and the constant-voltage and constant-current step-by-step circuit 206 is connected. Is connected to the second terminal of the power conversion circuit 202. The constant voltage and constant current binning circuit 206 may include a control chip U1 and a first resistor R1.

In one embodiment, as shown in FIG. 5, the control chip U1 may include a pin GATE and a pin CS. Pin GATE can be used as a current output control pin, and pin CS can be used as a current sampling pin. The pin GATE is connected to the first terminal of the constant-voltage constant-current binning circuit 206, that is, connected to the first terminal of the power conversion circuit 202. The pin CS is connected to the second terminal of the constant-voltage constant-current binning circuit 206, that is, is connected to the second terminal of the power conversion circuit 202. A first terminal of the first resistor R1 is connected to a second terminal of the constant-voltage constant-current binning circuit 206, and a second terminal of the first resistor R1 is grounded. The control chip U1 may further include a pin ADJ for receiving a current binning instruction to trigger the constant voltage and constant current binning circuit 206 to perform constant voltage and constant current binning control. The control chip U1 is provided with a plurality of voltage references to achieve multi-level current. For example, in one embodiment, eight reference voltages are set in the control chip U1. However, the embodiments of the present invention are not limited in this regard.

In one embodiment, the control chip U1 is a pulse-width-modulated constant-current and constant-voltage-constant-body circuit whose current can be controlled by an external communication program design, and the corresponding function can be implemented by an external program design.

Due to the high working voltage of some portable devices, multiple cells are usually connected in series to form a battery. In the process of charging this battery, the voltage of each battery cell is different due to the difference in capacity and self-discharge rate. At this time, balanced measures need to be taken to ensure safety and stability to prevent overheating. Charge. Therefore, in one embodiment, the charging system 200 may include a balancing circuit (not shown in the figure). For example, the balancing circuit may be composed of a resistor and a field effect tube in series, connected in parallel with the corresponding cell, and used to switch on the field effect tube when the cell charge reaches a predetermined voltage value, so that the current flowing through the cell is reduced. To prevent overcharging.

The charging system described in the present invention can support the charging of batteries with different numbers of batteries, and the batteries with different numbers of batteries can be charged by replacing the corresponding connection lines between the charging system and the batteries.

FIG. 6 shows a flowchart of a method 300 for battery charging according to an embodiment of the present invention. As shown in FIG. 6, the battery charging method 300 may include the following steps: Step S301: receiving an AC signal through a mains rectification filter circuit, and Rectify and filter the received AC electric signal; step S302: receive the rectified and filtered electric signal from the mains rectification filter circuit through the power conversion circuit and perform power conversion on the received electric signal; step S303: filter through the output rectification The circuit receives the power-converted electric signal from the power conversion circuit, and rectifies and filters the received electric signal to obtain a direct-current signal for directly charging the battery; and step S304: from the AC through the constant-voltage and constant-current stage circuit The outside of the signal power conversion system receives a current level instruction, and controls the power conversion circuit according to the current level instruction to implement stepwise constant current charging of the battery.

In the battery charging method 300, the constant voltage and constant current stage circuit has a plurality of voltage references, so that it can output corresponding multiple currents to implement the staged constant current control.

In the battery charging method 300, the current level instruction may include a pulse width modulated signal.

In the battery charging method 300, the current level instruction includes a current upshift instruction and a current downshift instruction.

In the battery charging method 300, the first terminal of the constant-voltage and constant-current step-by-step circuit is connected to the first terminal of the power conversion circuit, and the second terminal of the constant-voltage and constant-current step-by-step circuit is connected to the second terminal of the power conversion circuit. .

In the battery charging method 300, the constant voltage and constant current stage circuit includes a control chip and a first resistor, the control chip includes a pin GATE and a pin CS, the pin GATE serves as a current and power conversion output control pin, and the pin CS serves as a current Sampling foot.

In the battery charging method 300, the pin GATE is connected to the first terminal of the constant voltage and constant current stage circuit, the pin CS is connected to the second terminal of the constant voltage and constant current stage circuit, and the first terminal of the first resistor It is connected to the second terminal of the constant voltage and constant current stage circuit, and the second terminal of the first resistor is grounded.

In the battery charging method 300, the control chip is a pulse width modulated constant current and constant voltage product circuit whose current can be designed and controlled by an external communication program.

In one embodiment, the battery charging method 300 may further include: performing instant detection on each of the one or more cells in the battery through a voltage detection and control circuit. To obtain the instant voltage of each battery cell, and generate and output the current level instruction based on the predetermined charging model and the instant voltage; wherein, the constant voltage and constant current binning circuit in the AC signal power conversion system controls the input power conversion circuit by The current is used to perform step-by-step constant current control on the DC signal.

In one embodiment, the battery charging method 300 may further include: receiving a current level instruction from the voltage detection and control circuit through a signal isolation circuit and transmitting the current level instruction to the constant voltage and constant current binning circuit.

In the battery charging method 300, the output terminal of the output rectification filter circuit is connected to the first terminal of the charging switch circuit, the second terminal of the charging switch circuit is connected to the battery, and the third terminal of the charging switch circuit is connected to the voltage detection and control. The circuits are connected. The battery charging method 300 may further include: when the voltage detection and control circuit detects that the voltage of any one of the one or more cells is within a predetermined range, the charging switch circuit is turned on to charge the cell.

The following uses the charging system 200 shown in FIG. 5 as an example to describe in detail the manner in which the charging system according to the embodiment of the present invention implements constant voltage and constant current stepping control.

After the charging system 200 is connected to the charging socket and the battery 210 to be charged, the battery 210 starts to be charged. The voltage detection and control circuit 204 senses the instantaneous voltages of the cells B1, B2, and B3. If the voltage of the three cells is greater than 2.4V (the lowest voltage) and less than 4.2V (the maximum voltage), the voltage sensing and control circuit 204 generates a current upshift instruction, and sends the current upshift instruction to the signal isolation circuit 205 through the pin 20. The signal isolation circuit 205 transmits the current upshift command to the constant voltage and constant current step-up circuit 206. For example, the ADJ pin of the control chip U1 in the constant voltage and constant current step-up circuit 206 receives the current upshift command. The current upshift instruction instructs the constant voltage and constant current step-up circuit 206 to shift the current up one level. The voltage sensing and control circuit 204 may send multiple current upshift instructions to instruct the current upshift to multiple stages.

As described above, the control chip U1 is provided with a plurality of voltage references, which can implement multi-level current control. The CS pin of the control chip U1 samples the current flowing through R1, and obtains the voltage value of R1 based on the sampled current and the resistance value of R1. Based on the current upshift instruction and the preset charging model, the voltage reference value corresponding to the current upshift instruction can be obtained. The voltage value of R1 is compared with the voltage reference value to control the pulse width of the GATE pin. Q1 controls the conversion of power, that is, controls the constant current output of the transformer T1, thereby affecting the charging current input to the battery 210.

For example, when the voltage of battery cell B3 reaches 4.2V first, the downshift instruction is transmitted to the constant voltage and constant current binning circuit to the lowest level, and the balance circuit switch corresponding to battery cell B3 is turned on, thereby counteracting the current flowing through battery cell B3. Shunt to prevent battery B3 from being overcharged. At this time, battery B3 enters the charging and shunting stage to balance the circuit. Because the battery cells B1 and B2 do not reach the maximum voltage, the battery cells B1 and B2 continue to be charged in the manner of the minimum gear current as described above until the maximum voltage of 4.2V is reached and the charging is turned off. The above example merely describes the working principle of the charging method of the charging system 200 by way of example, and does not limit it.

The AC signal power conversion system, charging system, and method for battery charging provided by the embodiments of the present invention omit the DC-DC conversion circuit in the traditional charger, and can not only achieve constant voltage and constant current step-by-step control of charging, but also Simple structure and low cost. In addition, the AC signal power conversion system and charging system provided in the embodiments of the present invention can be used to charge a battery by connecting a plurality of cells in series.

The AC signal power conversion system, charging system and method for battery charging provided by the embodiments of the present invention can be applied to various batteries, especially batteries for drones.

The “one embodiment”, “another embodiment”, and “another embodiment” are mentioned above, but it should be understood that the features mentioned in each embodiment are not necessarily only applicable to this embodiment, but rather May be used in other embodiments. Features in one embodiment may be applied to another embodiment or may be included in another embodiment.

The ordinal numbers such as "first", "second", etc. were mentioned above, but it should be understood that these expressions are only for convenience of narrative and citation, and the restricted objects do not have a sequential relationship.

It should be understood that the digital subscripts of the devices and circuits mentioned above are also for convenience of description and reference, and there is no sequential relationship.

The present invention has been described above with reference to specific embodiments of the present invention, but those skilled in the art will understand that various modifications, combinations, and changes can be made to these specific embodiments without departing from the scope of the appended claims or their equivalents The spirit and scope of the present invention.

Claims (16)

An AC signal power conversion system for battery charging is characterized in that the AC signal power conversion system includes: a mains rectification filter circuit that receives an alternating current signal and rectifies the received alternating current signal And filtering; a power conversion circuit that receives the rectified and filtered electrical signal from the mains rectification filter circuit and performs power conversion on the received electrical signal; an output rectification filter circuit that outputs the rectification filter circuit from The power conversion circuit receives a power-converted electrical signal, rectifies and filters the received electrical signal to obtain a DC electrical signal directly used to charge the battery; and a constant-voltage constant-current binning circuit, the constant-voltage constant-current The binning circuit receives a current stage instruction from the outside of the AC signal power conversion system, and controls the power conversion circuit according to the current stage instruction to implement stepped constant current charging of the battery; wherein the constant voltage The first terminal of the constant current step-down circuit is connected to the first terminal of the power conversion circuit A second terminal of the constant-voltage constant-current step-up circuit is connected to a second terminal of the power conversion circuit; wherein the constant-voltage constant-current step-up circuit includes a control chip and a first resistor, and the control chip includes A pin GATE and a pin CS, the pin GATE serves as a current output control pin, and the pin CS serves as a current sampling pin; and wherein the pin GATE and the first of the constant voltage and constant current binning circuit The terminals are connected, the pin CS is connected to the second terminal of the constant-voltage constant-current step-by-step circuit, and the first terminal of the first resistor is connected to the second terminal of the constant-voltage and constant-current step-by-step circuit. Connected, and the second terminal of the first resistor is grounded. The AC signal power conversion system according to item 1 of the scope of patent application, wherein the constant voltage and constant current stage circuit has multiple voltage references, so that it can output corresponding multiple currents to achieve the staged constant current. control. The AC signal power conversion system according to item 1 of the patent application scope, wherein the current level instruction includes a pulse width modulated signal. The AC signal power conversion system according to item 1 of the scope of patent application, wherein the current level command includes a current upshift command and a current downshift command. The AC signal power conversion system according to item 1 of the scope of patent application, wherein the control chip is a pulse width modulated constant current and constant voltage product circuit whose current can be controlled by an external communication program design. A charging system for battery charging, characterized in that the charging system comprises: the AC signal power conversion system according to any one of items 1 to 5 of the scope of patent application; and a voltage detection and control circuit, which The voltage detection and control circuit performs instant detection on each of the one or more cells in the battery to obtain an instant voltage of each cell, and generates and outputs based on a predetermined charging model and the instant voltage. The current level instruction; wherein the constant voltage and constant current step-up circuit in the AC signal power conversion system performs step-wise constant-current control on the DC signal by controlling a current input to the power conversion circuit. The charging system according to item 6 of the scope of patent application, further comprising a signal isolation circuit that receives the current level instruction from the voltage detection and control circuit and transmits the current level instruction to all The constant voltage and constant current binning circuit is described. The charging system according to item 6 of the scope of patent application, further comprising a charging switch circuit, a first terminal of the charging switch circuit is connected to an output terminal of the output rectification filter circuit, and a second terminal of the charging switch circuit Is connected to the battery, and the third terminal of the charging switch circuit is connected to the voltage detection and control circuit, when the voltage detection and control circuit detects any of the one or more cells When the voltage of the battery cell is within a predetermined range, the charging switch circuit is turned on to charge the battery cell. A method for charging a battery, characterized in that the method comprises: receiving an alternating current signal through a mains rectification filter circuit and rectifying and filtering the received alternating current signal; and rectifying and filtering the mains rectification filter circuit from the mains through a power conversion circuit. Receive the rectified and filtered electrical signal and perform power conversion on the received electrical signal; receive the power converted electrical signal from the power conversion circuit through an output rectification filter circuit, and rectify and filter the received electrical signal to Obtaining a direct current signal for directly charging the battery; and receiving a current level instruction from the outside of the AC signal power conversion system through a constant voltage and constant current binning circuit, and controlling the power conversion circuit according to the current level instruction In order to achieve stepped constant current charging of the battery, wherein a first terminal of the constant voltage and constant current stepped circuit is connected to a first terminal of the power conversion circuit, and the constant voltage and constant current stepped circuit The second terminal of the power conversion circuit is connected to the second terminal of the power conversion circuit; The control chip includes a control chip and a first resistor. The control chip includes a pin GATE and a pin CS. The pin GATE serves as a current output control pin and the pin CS serves as a current sampling pin. Is connected to a first terminal of the constant-voltage constant-current step-by-step circuit, the pin CS is connected to a second terminal of the constant-voltage constant-current step-by-step circuit, and the first terminal of the first resistor is connected to all The second terminal of the constant voltage and constant current step-up circuit is connected, and the second terminal of the first resistor is grounded. The method according to item 9 of the scope of patent application, wherein the constant-voltage constant-current binning circuit has multiple voltage references, so that corresponding multiple currents can be output to implement the binning constant-current control. The method of claim 9, wherein the current level instruction comprises a pulse width modulated signal. The method according to item 9 of the scope of patent application, wherein the current level instruction includes a current upshift instruction and a current downshift instruction. The method according to item 9 of the scope of the patent application, wherein the control chip is a pulse width modulation, constant current and constant voltage circuit circuit whose current can be designed and controlled by an external communication program. The method according to any one of claims 9 to 13, further comprising: performing an instant detection on each of one or more of the batteries in the battery through a voltage detection and control circuit. To obtain the instantaneous voltage of each battery cell, and generate and output the current level instruction based on a predetermined charging model and the instantaneous voltage; wherein the constant voltage and constant current segmentation in the AC signal power conversion system The circuit performs step-by-step constant current control on the direct current signal by controlling a current input to the power conversion circuit. The method according to item 14 of the patent application scope, further comprising: receiving the current level instruction from the voltage detection and control circuit through a signal isolation circuit and transmitting the current level instruction to the constant voltage and constant current Binning circuit. The method according to item 14 of the scope of patent application, wherein an output terminal of the output rectification filter circuit is connected to a first terminal of a charging switch circuit, and a second terminal of the charging switch circuit is connected to the battery. And the third terminal of the charging switch circuit is connected to the voltage detection and control circuit, the method further includes: when the voltage detection and control circuit detects any one of the one or more cells When the voltage of the core is within a predetermined range, the charging switch circuit is turned on to charge the battery core.