Alternating current and direct current integrated input type commutation output circuit

Abstract

The utility model provides an alternating current and direct current integrated input type reversing output circuit, which relates to the field of power supply circuits and comprises an alternating current input end, a direct current input end, an alternating current and direct current switching unit, a power unit and a reversing switching unit. The output end of the AC / DC switching unit is electrically connected with the input end of the power unit, and the output end of the reversing switching unit is electrically connected with the input end of the reversing switching unit; the AC input end is electrically connected with a power distribution network; the direct current input end is electrically connected with the storage battery pack or the photovoltaic power generation assembly; and the commutation switching unit is used for switching the output direction, and has the advantages of being compatible with alternating-current and direct-current double-input power supplies and output commutation.

Description

Technical Field

[0001] The utility model relates to the field of power supply circuits, and particularly relates to an AC / DC integrated input type commutation output circuit. Background Art

[0002] In an AC / DC power module application system, the input power supply is an AC power grid. In actual application scenarios, if the power grid is abnormal, especially when the power grid loses power, the power module cannot work. In systems with high reliability requirements, in order to further ensure the reliable application of the power supply system, some systems need to have a backup power supply, thus forming a dual-input power supply system. The backup power supply system requires dual-input AC backup, or AC and DC dual-input backup. Especially with the wide application of DC power supply systems such as batteries and new energy power generation, the requirement for dual-input power supply backup of AC power grid and DC power supply in the system is increasing.

[0003] At present, the most commonly used solution in the power supply system is to use two independent power modules, one is an AC input power module, and the other is a DC input power module. The output ends are connected in parallel, and the two input type modules are mixed and applied in the system to enhance the reliability of the system power supply. However, this solution has a higher system complexity. The simultaneous presence of the two power modules makes the power supply device larger in size and the system configuration more difficult.

[0004] Therefore, it is necessary to provide an AC / DC integrated input type commutation output circuit for compatible with dual-input power supplies of AC and DC and output commutation. Summary of the Invention

[0005] The utility model provides an AC / DC integrated input type commutation output circuit, which includes an AC input end, a DC input end, an AC / DC switching unit, a power unit and a commutation switching unit. The AC input end and the DC input end are both electrically connected to the output end of the AC / DC switching unit. The output end of the AC / DC switching unit is electrically connected to the input end of the power unit. The output end of the commutation switching unit is electrically connected to the input end of the commutation switching unit. The AC input end is electrically connected to the distribution network. The DC input end is electrically connected to a battery pack or a photovoltaic power generation component. The commutation switching unit is used to switch the output direction.

[0006] Further, the power unit includes a plurality of power components connected in parallel. The input end of the power component is electrically connected to the output end of the AC / DC switching unit. The output end of the power component is electrically connected to the input end of the commutation switching unit.

[0007] Further, the number of the power components is determined according to the required total power.

[0008] Further, the power component includes a first rectifier diode circuit, an IGBT inverter, a high-frequency transformer, and a second rectifier diode circuit. The output end of the AC / DC switching unit is electrically connected to the input end of the first rectifier diode circuit. The output end of the first rectifier diode circuit is electrically connected to the input end of the IGBT inverter. The output end of the IGBT inverter is electrically connected to the input end of the high-frequency transformer. The output end of the high-frequency transformer is electrically connected to the input end of the second rectifier diode circuit. The output end of the second rectifier diode circuit is electrically connected to the input end of the commutation switching unit.

[0009] Further, the first rectifier diode circuit includes a first input end, a second input end, and a third input end. Phase A of the AC input end is electrically connected to the first input end. Phase B of the AC input end is electrically connected to the second input end. Phase C of the AC input end is electrically connected to the third input end. The positive pole of the DC input end is electrically connected to the first input end. The negative pole of the DC input end is electrically connected to the third input end.

[0010] Further, the first rectifier diode circuit includes a first rectifier diode, a second rectifier diode, and a third rectifier diode. The first rectifier diode is electrically connected to the first input end. The second rectifier diode is electrically connected to the second input end. The third rectifier diode is electrically connected to the third input end.

[0011] Further, the AC / DC switching unit includes a DC switching switch, an AC switching switch, and multiple power switching switch groups. Among them, each power switching switch group includes a first power switching switch and a second power switching switch. The number of power switching switch groups is the same as the number of power components. The DC switching switch is connected in series between the DC input end and the power unit. The AC switching switch is connected in series between the AC input end and the power unit. A first power switching switch is connected in series between each power component and the DC switching switch. A second power switching switch is connected in series between each power component and the AC switching switch.

[0012] Further, the commutation switching unit includes a first double-contact contactor and a second double-contact contactor. The first double-contact contactor is electrically connected to the positive output end of the power unit. The second double-contact contactor is electrically connected to the negative output end of the power unit.

[0013] Further, when the forward output is performed, the first contact of the first double-contact contactor and the second contact of the second double-contact contactor are closed, and the second contact of the first double-contact contactor and the first contact of the second double-contact contactor are opened; when the reverse output is performed, the second contact of the first double-contact contactor and the first contact of the second double-contact contactor are closed, and the first contact of the first double-contact contactor and the second contact of the second double-contact contactor are opened.

[0014] Further, it further includes a controller for controlling the states of the AC-DC switching unit and the commutation switching unit.

[0015] Compared with the prior art, a commutation output circuit with integrated AC-DC input provided by the present utility model has at least the following beneficial effects:

[0016] This circuit can accept both alternating current and direct current as inputs, and can obtain electrical energy from various power sources, such as power distribution networks, battery packs, or photovoltaic power generation modules, etc. This compatibility greatly increases the applicable range and flexibility of the circuit. Through the commutation switching unit, the circuit can easily switch the output direction to meet the requirements of different loads for the direction of electrical energy. This function is particularly important in application scenarios that require bidirectional power transmission or conversion. Since this circuit supports two input methods of AC and DC, when one of the input methods fails, it can quickly switch to the other input method to ensure continuous power supply of the circuit. This redundant design improves the reliability and stability of the circuit. The power unit can achieve efficient power conversion and transmission. This helps to reduce energy loss and improve the energy efficiency of the entire circuit. This circuit can be applied to various fields and scenarios, such as new energy power generation, energy storage systems, electric vehicle charging stations, etc. Its wide applicability makes it have great market potential and application value. Description of the Drawings

[0017] This specification will further illustrate in the manner of exemplary embodiments, and these exemplary embodiments will be described in detail through the drawings. These embodiments are not restrictive. In these embodiments, the same numbers represent the same structures, where:

[0018] Figure 1 is a circuit schematic diagram of a commutation output circuit with integrated AC-DC input according to some embodiments of this specification.

[0019] Figure 2 is a schematic diagram of the controller controlling the states of the AC-DC switching unit and the commutation switching unit according to some embodiments of this specification.

[0020] In the figure, 1, the first rectifier diode circuit; 2, the IGBT inverter; 3, the high-frequency transformer; 4, the second rectifier diode circuit. Detailed Embodiments

[0021] To more clearly illustrate the technical solutions of the embodiments of this specification, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some examples or embodiments of this specification. For those of ordinary skill in the art, without creative efforts, this specification can also be applied to other similar scenarios based on these drawings. Unless obvious from the language context or otherwise stated, the same reference numerals in the figures represent the same structure or operation.

[0022] Figure 1 is a circuit schematic diagram of an AC-DC integrated input type commutation output circuit shown according to some embodiments of this specification, as Figure 1 shown, an AC-DC integrated input type commutation output circuit may include an AC input terminal, a DC input terminal, an AC-DC switching unit, a power unit, and a commutation switching unit. The AC input terminal and the DC input terminal are both electrically connected to the output terminal of the AC-DC switching unit. The output terminal of the AC-DC switching unit is electrically connected to the input terminal of the power unit. The output terminal of the commutation switching unit is electrically connected to the input terminal of the commutation switching unit. The AC input terminal is electrically connected to the power distribution network. The DC input terminal is electrically connected to the battery pack or the photovoltaic power generation module. The commutation switching unit is used to switch the output direction to meet the power supply requirements of different loads. For example, in some application scenarios, the load may require forward or reverse power supply.

[0023] Specifically, first, the AC-DC switching unit is used to determine which input power source to use: AC power or DC power. When selecting AC input as the power source, the power distribution network is electrically connected to the power unit, and the connection between the battery pack or the photovoltaic power generation module and the power unit is disconnected. When selecting DC input as the power source, the battery pack or the photovoltaic power generation module is electrically connected to the power unit, and the connection between the power distribution network and the power unit is disconnected.

[0024] Preferably, the power unit includes a plurality of power components connected in parallel. The input terminal of the power component is electrically connected to the output terminal of the AC-DC switching unit. The output terminal of the power component is electrically connected to the input terminal of the commutation switching unit. Since the power of a single power component is limited, multiple power components can be connected in parallel according to the total power. As Figure 1 shown, the number of power components connected in parallel can be 3. The number of power components is determined according to the required total power.

[0025] Preferably, the AC / DC switching unit includes a DC switching switch, an AC switching switch, and multiple power switching switch groups. Among them, each power switching switch group includes a first power switching switch and a second power switching switch. The number of power switching switch groups is the same as the number of power components. The DC switching switch is connected in series between the DC input end and the power unit, and the AC switching switch is connected in series between the AC input end and the power unit. A first power switching switch is connected in series between each power component and the DC switching switch, and a second power switching switch is connected in series between each power component and the AC switching switch.

[0026] As Figure 1 shown, the DC switching switch includes a DC circuit breaker QF2, and the AC switching switch includes an AC circuit breaker QF1. When AC input is selected as the power supply, the AC circuit breaker QF1 is in the closed state, and the DC circuit breaker QF2 is in the open state. When DC input is selected as the power supply, the AC circuit breaker QF1 is in the open state, and the DC circuit breaker QF2 is in the closed state.

[0027] As Figure 1 shown, the first power switching switches of the three power switching switch groups are respectively the DC circuit breakers QF6, QF7, and QF8, and the second power switching switches of the three power switching switch groups are respectively the AC circuit breakers QF3, QF4, and QF5. When AC input is selected as the power supply, the AC circuit breakers QF3, QF4, and QF5 are in the closed state, while the DC circuit breakers QF6, QF7, and QF8 are all in the open state. When DC input is selected as the power supply, the AC circuit breakers QF3, QF4, and QF5 are in the open state, while the DC circuit breakers QF6, QF7, and QF8 are all in the closed state.

[0028] As Figure 1 shown, preferably, the power component includes a first rectifier diode circuit 1, an IGBT inverter 2, a high-frequency transformer 3, and a second rectifier diode circuit 4. The output end of the AC / DC switching unit is electrically connected to the input end of the first rectifier diode circuit 1. The output end of the first rectifier diode circuit 1 is electrically connected to the input end of the IGBT inverter 2. The output end of the IGBT inverter 2 is electrically connected to the input end of the high-frequency transformer 3. The output end of the high-frequency transformer 3 is electrically connected to the input end of the second rectifier diode circuit 4. The output end of the second rectifier diode circuit 4 is electrically connected to the input end of the commutation switching unit.

[0029] Preferably, the first rectifier diode circuit 1 includes a first input terminal, a second input terminal, and a third input terminal. The A phase of the AC input terminal is electrically connected to the first input terminal, the B phase of the AC input terminal is electrically connected to the second input terminal, and the C phase of the AC input terminal is electrically connected to the third input terminal. The positive pole of the DC input terminal is electrically connected to the first input terminal, and the negative pole of the DC input terminal is electrically connected to the third input terminal.

[0030] Preferably, the first rectifier diode circuit 1 includes a first rectifier diode, a second rectifier diode, and a third rectifier diode. The first rectifier diode is electrically connected to the first input terminal, the second rectifier diode is electrically connected to the second input terminal, and the third rectifier diode is electrically connected to the third input terminal. By way of example only, the first input terminal, the second input terminal, and the third input terminal may be cables or copper bars. The first rectifier diode, the second rectifier diode, and the third rectifier diode may be high-voltage diodes MFDC3000634.

[0031] Specifically, the power component is rectified by the first rectifier diode circuit 1 compatible with AC-DC input to obtain a stable DC source, and then the DC source is converted into high-frequency alternating current by the IGBT inverter 2. Finally, a stable direct current is output through the high-frequency transformer 3 and the second rectifier diode circuit 4. This process makes full use of the characteristics of the first rectifier diode circuit 1, the IGBT inverter 2, the high-frequency transformer 3, and the second rectifier diode circuit 4 to achieve efficient and stable power conversion and output.

[0032] The high-frequency transformer 3 is an integrated water-cooled type. Through a special winding, the output voltage is made into a wide-range voltage compatible with AC-DC input. The voltage range can be determined according to actual needs. There are 4 groups of magnetic cores and independent windings inside the high-frequency transformer 3. The primary side is in series and the secondary side is in parallel. Wound according to the lowest voltage ratio, it can include the voltage input range after AC-DC input rectification.

[0033] As Figure 1 shown, preferably, the AC-DC switching unit includes a DC switching switch, an AC switching switch, and multiple power switching switch groups. Among them, the power switching switch group includes a first power switching switch and a second power switching switch. The number of power switching switch groups is the same as the number of power components. The DC switching switch is connected in series between the DC input terminal and the power unit, and the AC switching switch is connected in series between the AC input terminal and the power unit. A first power switching switch is connected in series between each power component and the DC switching switch, and a second power switching switch is connected in series between each power component and the AC switching switch.

[0034] As Figure 1As shown in the figure, the commutation switching unit includes a first double-contact contactor and a second double-contact contactor. The first double-contact contactor is electrically connected to the positive output terminal of the power unit, and the second double-contact contactor is electrically connected to the negative output terminal of the power unit. When outputting in the forward direction, the first contact S1 of the first double-contact contactor and the second contact S4 of the second double-contact contactor are closed, and the second contact S2 of the first double-contact contactor and the first contact S3 of the second double-contact contactor are open. When outputting in the reverse direction, the second contact S2 of the first double-contact contactor and the first contact S3 of the second double-contact contactor are closed, and the first contact S1 of the first double-contact contactor and the second contact S4 of the second double-contact contactor are open.

[0035] Figure 2 is a schematic diagram of the controller controlling the states of the AC-DC switching unit and the commutation switching unit according to some embodiments of this specification, as Figure 2 shown. Preferably, an AC-DC integrated input commutation output circuit may further include a controller for controlling the states of the AC-DC switching unit and the commutation switching unit.

[0036] Specifically, the controller will control the state of the AC-DC switching unit through parameters such as duty cycle, output current, voltage, and power. When in the DC input of the photovoltaic or battery pack, when the duty cycle is less than the maximum value and the power can meet the set power output, it will maintain the DC input mode, control the AC circuit breaker QF1 to be in the open state, and the DC circuit breaker QF2 to be in the closed state. When there is a sudden drop in the DC voltage, less than the set alarm value, and the duty cycle reaches the maximum value but still fails to meet the set output power, the controller will gradually reduce the duty cycle to 0, stop the machine, automatically trip the DC circuit breaker QF2, and then close the AC circuit breaker QF1, that is, switch to the AC input mode. When in the AC input, if it is detected that the DC voltage rises to the set steady-state value, it will be switched back to the DC input mode in the same way, and the photovoltaic or battery pack DC input will be preferentially used to save grid electric energy.

[0037] When outputting in the forward direction, the controller controls the first contact S1 of the first double-contact contactor and the second contact S4 of the second double-contact contactor to be closed. When switching to the reverse output, first reduce the duty cycle to 0, open the first contact S1 of the first double-contact contactor and the second contact S4 of the second double-contact contactor, then close the second contact S2 of the first double-contact contactor and the first contact S3 of the second double-contact contactor, and increase the duty cycle until the set power is reached.

[0038] Finally, it should be understood that the embodiments described in this specification are only used to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification may be regarded as consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly presented and described in this specification.

Claims

1. An AC-DC integrated input commutation output circuit, characterized in that, It includes an AC input terminal, a DC input terminal, an AC / DC switching unit, a power unit and a commutation switching unit. The AC input terminal and the DC input terminal are both electrically connected to the output terminal of the AC / DC switching unit. The output terminal of the AC / DC switching unit is electrically connected to the input terminal of the power unit. The output terminal of the commutation switching unit is electrically connected to the input terminal of the commutation switching unit; The AC input terminal is electrically connected to the distribution network; The DC input terminal is electrically connected to the battery pack or the photovoltaic power generation module; The commutation switching unit is used to switch the output direction.

2. The AC-DC integrated input type commutation output circuit according to claim 1, wherein The power unit includes a plurality of power components connected in parallel. The input terminal of the power component is electrically connected to the output terminal of the AC / DC switching unit. The output terminal of the power component is electrically connected to the input terminal of the commutation switching unit.

3. The AC / DC integrated input type commutation output circuit according to claim 2, characterized in that, The number of the power components is determined according to the required total power.

4. The AC-DC integrated input type commutation output circuit according to claim 2, wherein, The power component includes a first rectifier diode circuit, an IGBT inverter, a high-frequency transformer and a second rectifier diode circuit. The output terminal of the AC / DC switching unit is electrically connected to the input terminal of the first rectifier diode circuit. The output terminal of the first rectifier diode circuit is electrically connected to the input terminal of the IGBT inverter. The output terminal of the IGBT inverter is electrically connected to the input terminal of the high-frequency transformer. The output terminal of the high-frequency transformer is electrically connected to the input terminal of the second rectifier diode circuit. The output terminal of the second rectifier diode circuit is electrically connected to the input terminal of the commutation switching unit.

5. The AC-DC integrated input type commutation output circuit according to claim 4, characterized in that, The first rectifier diode circuit includes a first input terminal, a second input terminal and a third input terminal. The A phase of the AC input terminal is electrically connected to the first input terminal. The B phase of the AC input terminal is electrically connected to the second input terminal. The C phase of the AC input terminal is electrically connected to the third input terminal. The positive pole of the DC input terminal is electrically connected to the first input terminal. The negative pole of the DC input terminal is electrically connected to the third input terminal.

6. The AC-DC integrated input type commutation output circuit according to claim 5, characterized in that, The first rectifier diode circuit includes a first rectifier diode, a second rectifier diode and a third rectifier diode. The first rectifier diode is electrically connected to the first input terminal. The second rectifier diode is electrically connected to the second input terminal. The third rectifier diode is electrically connected to the third input terminal.

7. A AC / DC integrated input commutation output circuit according to claim 2, characterized in that The AC / DC switching unit includes a DC switching switch, an AC switching switch and a plurality of power switching switch groups. Among them, the power switching switch group includes a first power switching switch and a second power switching switch. The number of the power switching switch groups is the same as the number of the power components. The DC switching switch is connected in series between the DC input terminal and the power unit. The AC switching switch is connected in series between the AC input terminal and the power unit. A first power switching switch is connected in series between each power component and the DC switching switch. A second power switching switch is connected in series between each power component and the AC switching switch.

8. A AC-DC integrated input commutation output circuit according to any one of claims 1-7, characterized in that, The commutation and switching unit includes a first double-contact contactor and a second double-contact contactor. The first double-contact contactor is electrically connected to the positive output terminal of the power unit, and the second double-contact contactor is electrically connected to the negative output terminal of the power unit.

9. A AC-DC integrated input commutation output circuit according to any one of claims 1-6, characterized in that, During forward output, the first contact of the first double-contact contactor and the second contact of the second double-contact contactor are closed, and the second contact of the first double-contact contactor and the first contact of the second double-contact contactor are open; During reverse output, the second contact of the first double-contact contactor and the first contact of the second double-contact contactor are closed, and the first contact of the first double-contact contactor and the second contact of the second double-contact contactor are open.

10. A AC-DC integrated input commutation output circuit according to any one of claims 1-7, characterized in that It further includes a controller for controlling the states of the AC / DC switching unit and the commutation and switching unit.

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