Charging system for electric vehicle using lead-acid battery

Abstract

The utility model discloses a charging system for an electric vehicle using a lead-acid battery, which comprises an alternating current, a filter, a transformer, a rectifier bridge and an MCU (Microprogrammed Control Unit), the alternating current is connected with a common mode inductor through the filter, and the common mode inductor is connected with the transformer; the transformer is connected with the rectifier bridge, and the rectifier bridge is connected with the voltage stabilizing circuit; the voltage stabilizing circuit is provided with four paths of outputs, and each path is provided with a high-speed switch MOS (Metal Oxide Semiconductor) tube; and the MCU is respectively connected with the high-speed switch MOS tube and the voltage circuit. The beneficial effects of the utility model are that through changing the charging strategy, the charger can output independent charging voltage according to the state of each battery, the safety during charging is ensured, and the service life of each battery can be greatly prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of lead-acid battery charging, in particular to a charging system for an electric vehicle using a lead-acid battery. Background Art

[0002] With the increasing popularity of electric bicycles and tricycles, based on cost considerations, more than 90% of the vehicles on the market use lead-acid batteries as power sources, mainly on the three voltage platforms of 48V, 60V and 72V, and these voltage platforms are all based on single 12V lead-acid batteries connected in series. These batteries do not have a BMS monitoring and protection system like lithium batteries. Therefore, when the charger charges the battery, the single battery has no voltage and temperature detection system. However, due to the difference in the internal resistance of the single battery, the voltage difference of the single battery will become larger and larger over time, which is prone to overcharging or bulging. This poses a great risk when using or charging. At present, the news often sees electric vehicles in a certain community spontaneously igniting at night, causing damage to a large number of vehicles and community buildings, and causing great damage to residents' property and personal safety.

[0003] At present, most of the two-wheeled electric bicycles, electric motorcycles, tricycles and low-speed four-wheel vehicles have the following problems: the solid lead-acid batteries used are basically 48V, 60V and 72V, and the number of battery cells is 4, 5 or 6 in series; the battery packs of these vehicles often do not have a BMS battery management system. Although the nominal voltage of each battery is 12V, they are directly charged at a high voltage (such as the maximum charging voltage of the 48V platform can reach 59V). Due to the difference in the internal resistance of the single battery, over time, a single battery is prone to overvoltage or overtemperature during charging, which is easy to cause danger. Based on cost considerations, the lead-acid battery system of electric vehicles on the market will not add a battery management system, and the charger only charges a group of batteries when charging, and cannot manage and charge a single battery.

[0004] Therefore, a charging system for electric vehicles using lead-acid batteries is proposed. Summary of the invention

[0005] The purpose of the utility model is to provide a charging system for electric vehicles using lead-acid batteries to solve the problems raised in the above background technology.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A charging system for electric vehicles using lead-acid batteries, comprising alternating current, filtering, a transformer, a rectifier bridge, and an MCU, wherein the alternating current is connected to a common-mode inductor through filtering, and the common-mode inductor is connected to a transformer;

[0008] The transformer is connected to a rectifier bridge, and the rectifier bridge is connected to a voltage stabilizing circuit;

[0009] The voltage stabilizing circuit has four outputs, and each output is provided with a high-speed switching MOS tube;

[0010] The MCU is connected to the high-speed switch MOS tube and the voltage stabilizing circuit respectively.

[0011] Furthermore, the alternating current is 220V.

[0012] Furthermore, the transformer converts 220V AC power into 60V AC power.

[0013] Furthermore, the MCU is connected to a voltage stabilizing circuit via a DC / DC.

[0014] Furthermore, the MCU is provided with a MOS driving module and a voltage acquisition module, and the MOS driving module and the voltage acquisition module are connected to the high-speed switch MOS tube.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] By changing the charging strategy, the charger can output independent charging voltage according to the status of each battery, ensuring the safety of charging, while the life of each battery can be greatly extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a system block diagram of the utility model;

[0018] Figure 2 It is a schematic diagram of the control cycle of the utility model. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Example

[0020] See also Figure 1-2 , the utility model provides a technical solution:

[0021] A charging system for electric vehicles using lead-acid batteries includes AC power, filtering, transformers, rectifier bridges, and MCUs. The AC power is connected to a common-mode inductor through filtering, and the common-mode inductor is connected to a transformer, so that 220V AC power reaches the transformer through filtering and common-mode inductance, and the voltage is changed from 220V AC power to 60V AC power. The transformer is connected to a rectifier bridge, and the rectifier bridge is connected to a voltage stabilizing circuit (which is changed into a stable 60V DC power through the rectifier bridge and the voltage stabilizing circuit). The voltage stabilizing circuit is provided with four outputs (divided into four outputs), each of which has a high-speed switching MOS tube, and each of which is independently controlled by a PWM wave output by an I / O port of the MCU.

[0022] Among them, the MCU is connected to the high-speed switching MOS tube and the voltage stabilizing circuit respectively, and the MCU is connected to the voltage stabilizing circuit through DC / DC. The MCU is provided with a MOS driving module and a voltage acquisition module, and the MOS driving module and the voltage acquisition module are connected to the high-speed switching MOS tube.

[0023] Working principle:

[0024] In a control cycle, each MOS takes up 1 / 4 of the cycle. In this cycle, each MOS tube output voltage can output a maximum voltage of about 15V after filtering. At the same time, in each 1 / 4 occupation cycle, the MCU outputs a PWM wave to adjust the duty cycle to control the output voltage to change between 12V-15V.

[0025] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A charging system for electric vehicles using lead-acid batteries, including AC power, filtering, transformer, rectifier bridge, and MCU, characterized in that: The alternating current is connected to a common mode inductor through filtering, and the common mode inductor is connected to a transformer; The transformer is connected to a rectifier bridge, and the rectifier bridge is connected to a voltage stabilizing circuit; The voltage stabilizing circuit has four outputs, and each output is provided with a high-speed switching MOS tube; The MCU is connected to the high-speed switch MOS tube and the voltage stabilizing circuit respectively.

2. The charging system for electric vehicles using lead-acid batteries according to claim 1, characterized in that: The alternating current is 220V.

3. The charging system for electric vehicles using lead-acid batteries according to claim 2, characterized in that: The transformer converts 220V AC power into 60V AC power.

4. The charging system for electric vehicles using lead-acid batteries according to claim 1, characterized in that: The MCU is connected to a voltage stabilizing circuit via a DC / DC.

5. The charging system for electric vehicles using lead-acid batteries according to claim 1, characterized in that: The MCU is provided with a MOS driving module and a voltage collecting module, and the MOS driving module and the voltage collecting module are connected with a high-speed switching MOS tube.

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