Special charger for sodium ion battery

Abstract

The utility model discloses a special charger for a sodium ion battery. The special charger comprises an AC input module, a bridge rectifier filter module, a PFC booster circuit, a high-frequency isolation transformer, a synchronous rectifier module and a DC voltage output module which are connected in sequence, the system further comprises a PWM control circuit and a negative feedback voltage stabilization and constant-voltage and constant-current control circuit. Filtering and rectification are carried out through the bridge type rectification filtering module, the real-time capacity of a load battery charging loop is detected through the negative feedback voltage stabilization and constant-voltage and constant-current control circuit and is fed back to the PWM control circuit to control the switch control frequency, and then the PFC booster circuit and the high-frequency isolation transformer are controlled to carry out energy conversion. And finally, the required current is output through the synchronous rectification module, so that stable-voltage and constant-voltage and constant-current charging is realized, and the charging range can be changed along with the internal capacity of the battery.

Description

Technical Field

[0001] The utility model relates to the technical field of sodium ion battery charging, in particular to a special charger for sodium ion batteries. Background Art

[0002] The industry standards for electric two- and three-wheeled vehicles are constantly being refined, placing higher demands on vehicle safety, environmental friendliness, and endurance, driving the industry towards high-quality development. The use of multi-series and multi-parallel sodium-ion battery packs can effectively ensure vehicle safety and pollution-free operation while also meeting vehicle endurance requirements. Sodium-ion batteries are a new type of rechargeable new energy product that can be fully replaced with lead-acid or lithium-ion batteries. However, due to the early stages of market adoption, many supporting products are not yet available or are incomplete. Therefore, dedicated sodium-ion battery chargers are specifically designed to address the charging challenges of multi-series and multi-parallel sodium-ion battery packs. Commonly used lithium-ion chargers and battery chargers on the market cannot meet the charging voltage requirements of sodium-ion batteries due to their different charging voltage ranges. For example, the charging range of a 48V sodium-ion charger is 28.8V-62.4V, while the voltage range of a 48V lithium-ion charger is 35V-54.6V, and the charging range of a 48V battery is 42V-54V. The charging voltage range of a 60V sodium-ion charger is 36V-78V, while the charging range of a 60V lithium-ion battery is 43.2V-68V, and the charging range of a 60V battery is 52.5V-67.5V. Comparing these data reveals that the charging voltage range of sodium-ion chargers is wider than that of other rechargeable batteries, which is the main reason why there are currently no chargers on the market that can charge sodium batteries. Utility Model Content

[0003] In order to overcome the defects of the prior art, the utility model provides a charger dedicated to sodium ion batteries.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] The utility model provides a dedicated charger for sodium ion batteries, comprising an AC input module, a bridge rectifier filter module, a PFC boost circuit, a high-frequency isolation transformer, a synchronous rectifier module and a DC voltage output module connected in sequence; and also comprising a PWM control circuit, a negative feedback voltage stabilization circuit and a constant voltage and constant current control circuit;

[0006] The bridge rectifier filter module includes a π-type filter LC circuit and a bridge rectifier circuit connected in sequence;

[0007] The PWM control circuit is connected to the PFC boost circuit and the high-frequency isolation transformer respectively, and is used to modulate the switching control frequency of the sodium-ion battery dedicated charger, thereby controlling the output voltage and energy conversion of the high-frequency isolation transformer;

[0008] The PFC boost circuit is used to be connected in series with the input voltage to boost the voltage;

[0009] The high-frequency isolation transformer is used to convert the input voltage up or down;

[0010] The negative feedback voltage stabilization and constant voltage and constant current control circuit is used to detect the current output by the synchronous rectification module and feed it back to the PWM control circuit;

[0011] The DC voltage output module is connected to the battery pack to be charged and is used to output a DC constant current voltage that meets the requirements.

[0012] As a preferred technical solution, the AC input module is connected to an external 220V AC voltage power grid via a three-core or two-core power connection line.

[0013] As a preferred technical solution, the π-type filter LC circuit includes an inductor L connected in series with the input voltage and a capacitor connected in parallel with the input voltage, and reduces the AC component in the output voltage through charging and discharging of the capacitor.

[0014] As a preferred technical solution, the bridge rectifier circuit includes four diodes connected in a "bridge" structure, which are used to convert alternating current into unidirectional pulsating direct current.

[0015] As a preferred technical solution, the PFC boost circuit includes an inductor, a diode, a switch tube and a capacitor; the inductor and the diode are connected in series to the positive electrode of the output voltage, the switch tube is connected in parallel between the inductor and the diode, and the capacitor is connected in parallel between the diode and the positive electrode of the output voltage.

[0016] As a preferred technical solution, the synchronous rectification module includes a rectifier tube, an inductor, a switch tube, a capacitor, a control IC and a unidirectional conduction tube, and is configured as follows:

[0017] The control IC is connected to the positive electrode of the capacitor and is used to extract the feedback signal and control the on and off of the switch tube;

[0018] When the switch tube is turned on, the inductor converts electrical energy and stores it into magnetic field energy, and outputs a DC voltage to the outside; when the switch tube is turned off, the inductor converts the stored magnetic field energy into electrical energy and releases it, the inductor charges the capacitor, and outputs a DC voltage to the outside.

[0019] As a preferred technical solution, the negative feedback voltage stabilization and constant voltage and constant current control circuit switches to a constant voltage mode or a constant current mode according to voltage and current settings and the connected load.

[0020] As a preferred technical solution, the PWM control circuit converts the amplitude of the received voltage into a switching pulse signal with a certain width, and then modulates the switching control frequency of the sodium ion battery dedicated charger.

[0021] As a preferred technical solution, the DC voltage output module performs constant current charging when the voltage of the battery pack to be charged is in the range of 28.8V-62.4V; and performs constant voltage trickle charging when the voltage of the battery pack to be charged is greater than or equal to 62.4V.

[0022] As a preferred technical solution, it also includes a charger indicator light. When the battery is in charging state, the power charger indicator light is set to red, and when fully charged, it is set to green.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] (1) The utility model uses a bridge rectifier filter module to perform filtering and rectification, uses a negative feedback voltage stabilization and constant voltage and constant current control circuit to detect the real-time capacity of the load battery charging circuit and feeds it back to the PWM control circuit to control the switch control frequency, thereby controlling the PFC boost circuit and the high-frequency isolation transformer to perform energy conversion, and finally outputs the required current through the synchronous rectifier module to achieve voltage stabilization and constant voltage and constant current charging, and the charging range can vary with the internal capacity of the battery.

[0025] (2) The utility model has the characteristics of simple structure, easy implementation and convenient operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of the dedicated charger for sodium ion batteries in the utility model;

[0027] Figure 2 It is a structural diagram of the bridge rectifier circuit and the PFC boost circuit in the utility model. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0029] Example 1

[0030] In this utility model, 220V AC is first input to the charger via an AC connection line. After filtering through a Pi-type filter, it is rectified by a bridge rectifier, filtered by a high-voltage capacitor, and converted by an isolation transformer. A PWM controller promptly adjusts the PFC boost circuit. Simultaneously, based on the negative feedback loop signal, the PWM controller modulates the main circuit switching control frequency to control the output voltage and energy conversion of the main circuit's high-frequency transformer. The synchronous rectification frequency and the main control circuit frequency are adjusted in real time based on the capacity of the load sodium battery charging circuit, achieving constant voltage and constant current charging. The charging range varies with the internal capacity of the battery. When the battery voltage is between 28.8V and 62.4V, constant current charging is implemented. When the battery voltage reaches 62.4V, constant voltage trickle charging is implemented. When the battery is charging, the power charger indicator light turns red and automatically turns green when fully charged.

[0031] like Figure 1 As shown, a dedicated sodium ion battery charger provided in this embodiment 1 includes an AC input module, a bridge rectifier filter module, a PFC boost circuit, a high-frequency isolation transformer, a synchronous rectifier module, and a DC voltage output module connected in sequence; it also includes a PWM control circuit, a negative feedback voltage regulator and a programmable constant voltage and constant current control circuit, and a charger indicator light.

[0032] Furthermore, the AC input module is connected to an external 220V AC power grid via a three-core or two-core power connection line.

[0033] Furthermore, the bridge rectifier filter module includes a π-type filter LC circuit and a bridge rectifier circuit connected in sequence, which functions to remove unwanted harmonics;

[0034] The π-type filter LC circuit includes an inductor connected in series with the input voltage and a capacitor connected in parallel with the input voltage. The capacitor's main function is filtering, that is, reducing the AC component in the output voltage through the charging and discharging of the capacitor, thereby obtaining a smoother DC output.

[0035] like Figure 2 As shown, the bridge rectifier circuit includes four diodes connected in a "bridge" structure, which is used to convert AC current into unidirectional pulsating DC current.

[0036] Furthermore, the PFC boost circuit (i.e., power factor correction circuit) is used to boost the voltage in series with the input voltage, improve the power factor of the power supply, adjust the current waveform, and compensate for the phase difference between the current and voltage to improve the power factor. Figure 2 As shown, it includes an inductor, a diode, a switch tube and a capacitor; the inductor and the diode are connected in series to the positive electrode of the output voltage, the switch tube is connected in parallel between the inductor and the diode, and the capacitor is connected in parallel between the diode and the positive electrode of the output voltage.

[0037] Furthermore, to enable those skilled in the art to better understand the present application, this embodiment describes the operating principle of the PFC boost circuit. Specifically, the PFC boost circuit relies on rapid switching on and off relative to the ground to generate a self-induced voltage in the inductor, which is connected in series with the input DC voltage to produce a boost effect. When the switch is turned on, current flows through the inductor. Before the inductor is saturated, the current increases linearly, and electrical energy is stored in the inductor in the form of magnetic energy. At this time, the capacitor discharges to provide energy to the load. When the switch is turned off, a self-induced electromotive force is generated at both ends of the inductor to keep the current direction unchanged, so that V L With power supply V IN The capacitor and the load are connected in series to provide power, thus boosting the voltage.

[0038] Furthermore, the high-frequency isolation transformer is used to convert the input voltage up or down so that the output end can obtain the required voltage. The high-frequency isolation transformer has the advantages of small size, light weight, and high efficiency.

[0039] Furthermore, the synchronous rectification module uses a professional low-resistance power tube to replace the diode, which reduces the rectification loss, improves the conversion efficiency, and realizes the DC conversion function at the output end. Its structure includes a rectifier tube, an inductor, a switch tube, a capacitor, a control IC, and a unidirectional conduction tube, and is configured as follows:

[0040] The control IC is connected to the positive electrode of the capacitor and is used to extract the feedback signal and control the on and off of the switch tube;

[0041] When the switch is turned on, the inductor converts electrical energy into magnetic field energy and stores it, and outputs a DC voltage to the outside. When the switch is turned off, the inductor converts the stored magnetic field energy into electrical energy and releases it, charging the capacitor and outputting a DC voltage to the outside.

[0042] The one-way conducting tube is used to provide a path for the inductor to release electrical energy.

[0043] Furthermore, the negative feedback voltage stabilization and constant voltage and constant current control circuit is used to detect the current output by the synchronous rectification module and feed it back to the PWM control circuit to prevent circuit overload. That is, when the input signal current is too large, a negative signal current is fed back from the amplified output terminal to the input terminal to suppress the input signal current from further increasing.

[0044] In addition, the negative feedback voltage regulation and constant voltage and constant current control circuit also switches to constant voltage (CV) mode or constant current (CC) mode according to the voltage and current settings and the connected load.

[0045] The constant voltage mode means that a constant voltage is always provided regardless of the load; the constant voltage mode means that current is provided regardless of the voltage applied to the battery.

[0046] Furthermore, the PWM control circuit is respectively connected to the PFC boost circuit and the high-frequency isolation transformer to convert the amplitude of the received voltage into a switching pulse signal with a certain width, which is used to modulate the switching control frequency of the sodium-ion battery dedicated charger, thereby controlling the output voltage and energy conversion of the high-frequency isolation transformer.

[0047] Typically, a switching output circuit can only output a signal with a constant voltage amplitude. To output a signal with a varying voltage amplitude, such as a sine wave, this voltage amplitude must be converted into a pulse signal. A high-power circuit consists of a PWM circuit, a gate drive circuit, and a switching output circuit. The PWM circuit's primary function is to compare the amplitude of the triangular wave with the command signal (referring to the comparator function within the control IC) and simultaneously output a control signal that drives the switch. This control signal then controls the output voltage of the power circuit.

[0048] Furthermore, the DC voltage output module is connected to the battery pack to be charged, and is used to output a DC constant current voltage that meets the requirements.

[0049] The DC voltage output module has a charging voltage range of 28.8V-62.4V for 48V sodium-ion batteries; 36.0V-78.0V for 60V sodium-ion batteries; and 43.2V-93.6V for 72V sodium-ion batteries. Specifically, constant-current charging is performed when the battery pack voltage is between 28.8V and 62.4V; and constant-voltage trickle charging is performed when the battery pack voltage is greater than or equal to 62.4V.

[0050] Furthermore, the charger indicator light is set to red when the battery is in charging state, and to green when fully charged.

[0051] The above embodiments are preferred implementation methods of the present invention, but the implementation methods of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. Sodium ion battery charger, characterized in that: It includes an AC input module, a bridge rectifier filter module, a PFC boost circuit, a high-frequency isolation transformer, a synchronous rectifier module and a DC voltage output module connected in sequence; it also includes a PWM control circuit, a negative feedback voltage regulator and a constant voltage and constant current control circuit; The bridge rectifier filter module includes a π-type filter LC circuit and a bridge rectifier circuit connected in sequence; The PWM control circuit is connected to the PFC boost circuit and the high-frequency isolation transformer respectively, and is used to modulate the switching control frequency of the sodium-ion battery dedicated charger, thereby controlling the output voltage and energy conversion of the high-frequency isolation transformer; The PFC boost circuit is used to be connected in series with the input voltage to boost the voltage; The high-frequency isolation transformer is used to convert the input voltage up or down; The negative feedback voltage stabilization and constant voltage and constant current control circuit is used to detect the current output by the synchronous rectification module and feed it back to the PWM control circuit; The DC voltage output module is connected to the battery pack to be charged and is used to output a DC constant current voltage that meets the requirements.

2. The sodium ion battery charger according to claim 1, characterized in that: The AC input module is connected to an external 220V AC power grid via a three-core or two-core power connection line.

3. The sodium ion battery charger according to claim 1, characterized in that: The π-type filter LC circuit includes an inductor connected in series with the input voltage and a capacitor connected in parallel with the input voltage, and reduces the AC component in the output voltage through the charging and discharging of the capacitor C.

4. The sodium ion battery charger according to claim 1, characterized in that: The bridge rectifier circuit includes four diodes connected in a "bridge" structure, which is used to convert AC current into unidirectional pulsating DC current.

5. The sodium ion battery charger according to claim 1, characterized in that: The PFC boost circuit includes an inductor, a diode, a switch tube and a capacitor; the inductor and the diode are connected in series to the positive electrode of the output voltage, the switch tube is connected in parallel between the inductor and the diode, and the capacitor is connected in parallel between the diode and the positive electrode of the output voltage.

6. The sodium ion battery charger according to claim 1, characterized in that: The synchronous rectification module includes a rectifier tube, an inductor, a switch tube, a capacitor, a control IC and a unidirectional conduction tube, and is configured as follows: The control IC is connected to the positive electrode of the capacitor and is used to extract the feedback signal and control the on and off of the switch tube; When the switch tube is turned on, the inductor converts electrical energy and stores it into magnetic field energy, and outputs a DC voltage to the outside; when the switch tube is turned off, the inductor converts the stored magnetic field energy into electrical energy and releases it, the inductor charges the capacitor, and outputs a DC voltage to the outside.

7. The sodium ion battery charger according to claim 1, characterized in that: The negative feedback voltage stabilization and constant voltage and constant current control circuit switches to a constant voltage mode or a constant current mode according to voltage and current settings and the connected load.

8. The sodium ion battery charger according to claim 1, characterized in that: The PWM control circuit converts the amplitude of the received voltage into a switching pulse signal with a certain width, thereby modulating the switching control frequency of the sodium ion battery dedicated charger.

9. The sodium ion battery charger according to claim 7, characterized in that: The DC voltage output module performs constant current charging when the voltage of the battery pack to be charged is in the range of 28.8V-62.4V; and performs constant voltage trickle charging when the voltage of the battery pack to be charged is greater than or equal to 62.4V.

10. The sodium ion battery charger according to claim 1, characterized in that: Also included is a charger indicator light, which is set to red when the battery is charging and green when fully charged.

Images