Alternating-current and direct-current dual-purpose power generation charging station

Abstract

The invention discloses an AC-DC dual-purpose power generation charging station, which comprises a magneto, rectification units, an AC inversion output end and a DC output end, and is characterized in that the magneto is provided with a plurality of independent three-phase windings, and the rectification units are electrically connected with the independent three-phase windings respectively; the switching units are electrically connected with the rectifying units respectively and are used for carrying out alternating-current and direct-current switching on output; the load detection unit is used for detecting loads of the AC inverter output end and the DC output end; and the main control controller is used for driving the switching unit to carry out alternating current and direct current switching based on the load conditions of the AC inverter output end and the DC output end. Compared with the prior art, the scheme adopts a plurality of independent three-phase windings, and each independent three-phase winding is provided with an independent rectification unit, so that different rectification schemes can be formed, and different rectification schemes can be selected through the switching unit according to different requirements and ripple conditions, so that the influence is reduced, and the rectification efficiency is improved. The power supply efficiency can be improved, and the service life of equipment is prolonged.

Description

Technical Field

[0001] The invention relates to an AC / DC dual-purpose power generation and charging station, and in particular to an AC / DC dual-purpose power generation and charging station capable of reducing charging ripple. Background Art

[0002] As a highly efficient charging device, the charging station can quickly charge charging equipment such as electric vehicles. However, since electric vehicles currently use lithium batteries as power sources, lithium batteries have high requirements for charging ripple current and charging voltage. At present, in the existing low-cost controlled rectification scheme, a rectifier bridge or thyristor is generally used to directly perform full-bridge rectification on the AC output of the permanent magnet motor. The ripple after rectification of this scheme is positively correlated with the AC output frequency of the magnetic motor, and the higher the frequency, the smaller the ripple after rectification. Although the lithium battery needs low-power pretreatment in the early stage of battery depletion during the charging process, the charging current in the pretreatment stage is small, and the ripple current needs to meet the requirements. However, when the output power of the charger using the full-bridge rectification scheme is small, the speed will be relatively lower, and the influence of the engine speed fluctuation on the ripple will be correspondingly increased.

[0003] In addition, to meet the power needs of users, the charging station also has the function of AC output; in order to reduce the cost of the whole machine and realize multiple uses of one machine, the inverter part of this solution adopts a low-voltage inverter output AC solution, but when the AC inverter outputs, there is still the problem of the ripple of the DC part charging being affected.

[0004] Chinese patent document CN110224582A discloses a current ripple reduction circuit and charger, wherein the circuit comprises: a first transformer, a first end of the primary winding of the first transformer is connected to a first end of a DC capacitor on an output side of an external power factor correction circuit PFC, and a second end of the primary winding of the first transformer is connected to a first end of a first external DC load; the primary winding of the first transformer is used to couple the AC ripple current to the secondary winding of the first transformer; a first AC / DC converter, an input end of the first AC / DC converter is connected to the secondary winding of the first transformer, and an output end of the first AC / DC converter is connected to a DC capacitor on an external PFC output side; the first AC / DC converter is used to convert the AC ripple current coupled to the secondary winding of the first transformer into a DC current and output it to the DC capacitor on an external PFC output side. The above technical solution reduces the cost and loss of suppressing current ripple.

[0005] The prior art has the following disadvantages: the prior art suppresses the current ripple by connecting a current ripple reduction circuit in series with the branch of the DC load, which can reduce the cost and loss of suppressing the current ripple. However, the prior art also has the problem that the ripple caused by the inverter unit will also affect the charging of the DC part, thereby reducing the power supply efficiency and shortening the service life of the electrical equipment. Summary of the invention

[0006] In order to solve the technical problem that the DC part charging in the existing charger is affected and the power supply efficiency is reduced, the present invention provides an AC-DC dual-purpose power generation charging station, including a magnetic motor, a rectifier unit, an AC inverter output end and a DC output end, wherein: the magnetic motor is provided with a plurality of independent three-phase windings, the rectifier unit is provided with a plurality of and is electrically connected to the independent three-phase windings respectively; It also includes a plurality of switching units which are electrically connected to the rectifying units respectively and perform AC / DC switching on the output; A load detection unit for detecting loads at the AC inverter output end and the DC output end; The main controller drives the switching unit to perform AC / DC switching based on the load conditions of the AC inverter output and the DC output.

[0007] After analyzing the charger of the prior art, it is found that since the same motor winding is used in the prior art, the inverter unit will also affect the charging of the DC part. In this scheme, the magnetic motor is divided into multiple independent three-phase windings, and multiple rectifier units are also set accordingly. The AC inverter output end or the DC output end can be individually controlled by switching the switching unit. Therefore, in order to reduce the charging ripple, when a low-power DC output is required, a certain number of outputs are switched by the switching unit. If AC output is required, a certain number of AC inverter output ends are powered by the switching unit, and the power supply of the remaining number of AC inverter output ends is switched to eliminate the influence of the AC inverter output end on the ripple. Compared with the prior art, this scheme adopts multiple independent three-phase windings, and each independent three-phase winding is equipped with a separate rectifier unit, so that different rectification schemes can be formed. Different rectification schemes can be selected through the switching unit according to different needs and ripple conditions, thereby reducing the influence of the ripple, improving the power supply efficiency, and extending the service life of the equipment.

[0008] Preferably, the main control controller is preset with a DC load critical value of the DC load output and an AC load critical value of the AC load output; when the load condition of the AC inverter output terminal detected by the load detection unit exceeds the AC load critical value, the main control controller controls the switching unit to reduce the load output of the DC output terminal. In this solution, after setting the DC load critical value and the AC load critical value, when the load detection unit detects that the current AC load is too large, it can switch in time and reduce the load output of the DC output terminal, thereby reducing the situation where the inverter output terminal is overloaded due to the overload of the DC output terminal, and the operation is simple.

[0009] Preferably, the main controller is also provided with an identification device for detecting the battery charge and discharge status, and the main controller is also communicatively connected to the engine. In this solution, after the battery charge and discharge status is identified, the engine can be controlled according to the battery charge and discharge status through the communication connection with the engine, and the operation is simple.

[0010] Preferably, the main controller also obtains the charging power supply demand of the battery and adjusts the engine speed according to the charging power supply demand. In this solution, adjusting the engine speed according to the charging power supply demand can make the engine speed adapt to the actual demand of the battery, and the operation is simple.

[0011] Preferably, the main controller is preset with different charging current critical values. When the identification device identifies that the charging current required by the battery is at different charging current critical values, the main controller controls the switching unit to retain or close the connection between a certain number of rectifier units and the DC output end. In this solution, after different charging current critical values ​​are preset, the DC output end connected can be adjusted according to the relationship between the current actual charging current and different charging current critical values, so as to eliminate the influence on the ripple while meeting the charging demand, and the operation is simple.

[0012] Preferably, the charging current critical value includes a first critical value. When the identification device identifies that the charging current required by the battery is lower than the first critical value, the main control controller switching unit closes the connection between a certain number of rectifier units and the DC output terminal, and controls the engine speed to increase. In this solution, when the charging current is lower than the first critical value, the engine speed is increased to achieve low ripple current DC output, and the operation is simple.

[0013] Preferably, the charging current critical value includes a second critical value, and when the identification device identifies that the charging current required by the battery is higher than the second critical value, the main controller controls the switching unit to connect a certain number of rectifier units to the DC output terminal. In this solution, when the charging current is greater than the second critical value, a certain number of rectifier units are added to charge the DC, so that the maximum charging power output can be met, and the operation is simple.

[0014] Preferably, the charging current critical value includes a third critical value. When the identification device identifies that the charging current required by the battery is lower than the third critical value, the main control controller controls the switching unit to close the connection between a certain number of rectifier units and the DC output terminal, and controls the engine speed to decrease. In this solution, after the charging current is lower than the third critical value, a certain number of rectifier units are closed to charge the DC and the engine speed is increased, which can meet the low ripple current DC output and is simple to operate.

[0015] The present invention has the following beneficial effects: 1. In the present invention, by dividing the magnetic motor into a plurality of independent three-phase windings, and adopting a plurality of independently controllable rectification schemes for the rectification unit, different rectification schemes can be switched according to actual conditions to eliminate the influence of the AC inverter output end on the ripple; 2. In the present invention, the main controller can dynamically adjust the rectification scheme according to the actual output situation, thereby improving the user experience and meeting more AC power supply needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a module block diagram of an embodiment of an AC / DC dual-purpose power generation and charging station of the present invention; FIG2 (a) is a ripple diagram of an existing full-bridge rectification solution; FIG2 (b) is a numerical diagram of the charging ripple of the existing full-bridge rectification scheme; FIG3 (a) is a schematic diagram of ripples of the present invention; FIG3( b ) is a numerical diagram of the charging ripple of the present invention; Figure 4 This is a schematic diagram of ripple changes after the inverter output is involved; Figure 5 The diagram shows the speed change of the rectifier unit when the switch is turned off during the charging process. DETAILED DESCRIPTION

[0017] The following is further described in detail through specific implementation methods: 1. Definition Ripple current: refers to the periodic fluctuating current generated in the AC current in a DC power supply due to unstable power quality or circuit overload.

[0018] Inverter output: refers to the output of DC power into AC power: AC: generally refers to alternating current; DC: generally refers to direct current.

[0019] 2. The embodiment is basically as shown in the attached Figure 1 As shown: an AC / DC dual-purpose power generation and charging station includes an engine, a magnetic motor, a rectifier unit, an AC inverter output end and a DC output end. The magnetic motor is provided with multiple independent three-phase windings, and the rectifier unit is provided with multiple and electrically connected to the independent three-phase windings respectively; in this embodiment, three groups of independent three-phase windings are provided, namely A winding, B winding and C winding, and three groups of rectifier units are correspondingly provided, namely controllable rectifier unit 1, controllable rectifier unit 2 and controllable rectifier unit 3.

[0020] A plurality of switching units are electrically connected to the rectifying units respectively and perform AC / DC switching on the outputs; in this embodiment, three switching units are provided correspondingly, namely, switching switch 1, switching switch 2 and switching switch 3.

[0021] A load detection unit for detecting loads at the AC inverter output end and the DC output end; The main controller drives the switching unit to perform AC / DC switching based on the load conditions of the AC inverter output and the DC output.

[0022] The main controller presets a DC load critical value of the DC load output and an AC load critical value of the AC load output; when the load condition of the AC inverter output end detected by the load detection unit exceeds the AC load critical value, the main controller controls the switching unit to reduce the load output of the DC output end.

[0023] The main control controller is also provided with an identification device for detecting the charging and discharging state of the battery, and the main control controller is also connected to the engine in communication. The main control controller also obtains the charging power supply demand of the battery and adjusts the speed of the engine according to the charging power supply demand. Specifically, the main control controller is preset with different charging current critical values. When the identification device identifies that the charging current required by the battery is at different charging current critical values, the main control controller controls the switching unit to retain or close the connection between a certain number of rectifier units and the DC output end. The charging current critical value includes a first critical value, a second critical value and a third critical value. When the identification device identifies that the charging current required by the battery is lower than the first critical value, the main control controller switching unit closes the connection between a certain number of rectifier units and the DC output end, and controls the engine speed to increase; when the identification device identifies that the charging current required by the battery is higher than the second critical value, the main control controller controls the switching unit to connect the connection between a certain number of rectifier units and the DC output end; when the identification device identifies that the charging current required by the battery is lower than the third critical value, the main control controller controls the switching unit to close the connection between a certain number of rectifier units and the DC output end, and controls the engine speed to decrease.

[0024] In the above process, the main controller identifies the preset critical value by measuring the battery voltage and battery capacity; taking a 60V lithium battery as an example, 48V, 52V, and 58.8V are set as the switching critical values ​​for three different charging modes; the battery capacity is used to adjust the required charging current based on the battery capacity obtained by the communication signal.

[0025] The opening and closing of the rectifier unit is preset based on the actual output current. Taking the state of three groups of three windings of 180A as an example, 65A and 130A are the trigger values ​​for opening the next winding, and 110A and 55A are the trigger values ​​for closing the next winding. The purpose of this setting is to avoid repeated switching during the switching process, which may cause the engine to wander.

[0026] The specific implementation process is as follows: When in use, the AC inverter output end or the DC output end can be powered separately through different switching units. In order to reduce charging ripple, when a low-power DC output is required, close switch 1 / switch 2 for DC output, and only retain switch 3 for DC output; the generator speed regulation only uses the DC terminal voltage as a control closed loop to increase the generator speed and thus reduce the charging ripple; if AC output is required at this time, turn on switch 1 / switch 2 to power the AC inverter output, and switch 3 turns off the power supply to the AC inverter to eliminate the influence of the inverter unit on the ripple. To improve the user experience, when the user end needs more AC power supply, the power supply of the AC inverter is prioritized, and the power supply output of the DC end is actively reduced. The main control CPU automatically makes dynamic adjustments based on the actual output situation, such as Figure 4 shown.

[0027] Taking a 28ah lithium battery as an example, the charging current ripple in the pre-charging stage needs to be controlled within 15A. However, in the existing full-bridge rectification scheme, during low-power pre-charging, the ripple current caused by the same speed fluctuation actually exceeds the ripple requirement of 15A due to the relatively low speed of the whole machine. As shown in Figure 2 (a) and Figure 2 (b), in the existing full-bridge rectification scheme, the charging ripple during 10A charging is measured to be 17.43A; in this embodiment, after the operating speed of the generator is increased by switching, the ripple current caused by the same speed fluctuation is actually lower than the ripple requirement of 15A, thereby achieving the purpose of reducing the ripple current. As shown in Figure 3 (a) and Figure 3 (b), the charging ripple during 10A charging is measured to be 11.5A.

[0028] In the actual charging process, after switching to constant voltage mode, the charging power will gradually decrease. At this time, shutting down one or two rectifier units to supply power can increase the speed of the generator set, thereby reducing the charging ripple. Figure 5 shown.

[0029] The above is only an embodiment of the present invention. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. An AC / DC dual-purpose power generation and charging station, comprising a magnetic motor, a rectifier unit, an AC inverter output terminal and a DC output terminal, characterized in that: The magnetic motor is provided with a plurality of independent three-phase windings, and the rectifier unit is provided with a plurality of rectifier units and is electrically connected to the independent three-phase windings respectively; It also includes a plurality of switching units which are electrically connected to the rectifying units respectively and perform AC / DC switching on the output; A load detection unit for detecting loads at the AC inverter output end and the DC output end; A main control controller drives the switching unit to perform AC / DC switching based on the load conditions of the AC inverter output terminal and the DC output terminal.

2. The AC / DC dual-purpose power generation and charging station according to claim 1, characterized in that: The main control controller presets a DC load critical value for the DC load output and an AC load critical value for the AC load output; when the load condition of the AC inverter output end detected by the load detection unit exceeds the AC load critical value, the main control controller controls the switching unit to reduce the load output of the DC output end.

3. The AC / DC dual-purpose power generation and charging station according to claim 2, characterized in that: The main control controller is also provided with an identification device for detecting the charging and discharging status of the battery, and the main control controller is also communicatively connected to the engine.

4. The AC / DC dual-purpose power generation and charging station according to claim 3, characterized in that: The main controller also obtains the charging and power supply requirements of the battery and adjusts the speed of the engine according to the charging and power supply requirements.

5. The AC / DC dual-purpose power generation and charging station according to claim 4, characterized in that: The main controller is preset with different charging current critical values. When the identification device identifies that the charging current required by the battery is at different charging current critical values, the main controller controls the switching unit to retain or close the connection between a certain number of the rectifying units and the DC output end.

6. The AC / DC dual-purpose power generation and charging station according to claim 5, characterized in that: The charging current critical value includes a first critical value. When the identification device identifies that the charging current required by the battery is lower than the first critical value, the switching unit of the main controller closes the connection between a certain number of rectifier units and the DC output end, and controls the engine speed to increase.

7. The AC / DC dual-purpose power generation and charging station according to claim 6, characterized in that: The charging current critical value includes a second critical value. When the identification device identifies that the charging current required by the battery is higher than the second critical value, the main controller controls the switching unit to connect a certain number of rectifier units to the DC output end.

8. The AC / DC dual-purpose power generation and charging station according to claim 7, characterized in that: The charging current critical value includes a third critical value. When the identification device identifies that the charging current required by the battery is lower than the third critical value, the main controller controls the switching unit to close the connection between a certain number of rectifier units and the DC output end, and controls the engine speed to decrease.

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