Multi-type input integrated power supply system

Abstract

The utility model discloses a multi-type input integrated power supply system, which comprises a PFC (Power Factor Correction) converter, a maximum power point tracking module and a DC / DC (Direct Current / Direct Current) converter, the output end of the AC input power supply is connected with the PFC converter, the output end of the photovoltaic input power supply is connected with the maximum power point tracking module, and the output ends of the PFC converter and the maximum power point tracking module are connected in parallel and then connected with the DC / DC converter. According to the technical scheme, the back-stage DC-DC converter is shared, the number of devices is reduced, the structure is simpler, and control is convenient.

Description

Technical Field

[0001] This utility model belongs to the field of power supply system technology and relates to a multi-type input integrated power supply system. Background Technology

[0002] Fossil fuels, as non-renewable energy sources, are becoming increasingly depleted, and the environmental pollution they cause is becoming more and more serious. Solar photovoltaic power generation, as a green new energy power supply method, is being used more and more widely. Its biggest advantage is that it is renewable and does not pollute the environment. The most significant characteristic of solar photovoltaic cells is that their external characteristic curve changes with light intensity and temperature. In order to maximize the utilization of solar energy, the DC-DC converter must be able to constantly control the output of the solar photovoltaic cells, keeping them operating near their maximum power point.

[0003] The proposed solar power systems cannot guarantee that the load can work continuously and stably. Therefore, in order to make full use of solar energy and ensure that the load can work normally and stably at all times, an auxiliary power source must be added as a backup when solar photovoltaic power cannot meet the load's power supply needs.

[0004] In the prior art, patent CN201010263033.7 discloses a combined solar photovoltaic and mains power supply system. This system includes a photovoltaic array, a mains power supply, a DC / DC converter, a PFC converter, and a DC / AC inverter. The photovoltaic array is connected to the DC / DC converter, and the mains power supply is connected to the PFC converter; both are connected together on the DC bus, and then the AC load is powered through the DC / AC inverter. This system uses a DC / DC converter and a PFC converter to regulate AC and photovoltaic power separately, essentially creating two separate systems. This structure is relatively complex and difficult to control. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-type input integrated power supply system that shares a common downstream DC-DC converter, reducing the number of components and simplifying the structure.

[0006] To achieve the above objectives, the basic solution of this utility model is: a multi-type input integrated power supply system, including a PFC converter, a maximum power point tracking module and a DC / DC converter;

[0007] The output of the AC input power supply is connected to the PFC converter, and the output of the photovoltaic input power supply is connected to the maximum power point tracking module. The outputs of the PFC converter and the maximum power point tracking module are connected in parallel to the DC / DC converter.

[0008] The working principle and beneficial effects of this basic scheme are as follows: The input is supplied by both AC and photovoltaic DC power. The AC input power is rectified and then output as a stable high-voltage DC through a PFC converter. The photovoltaic input power is also output as a stable high-voltage DC after passing through a maximum power point tracking module. These two high-voltage DC power sources are combined to power a DC-DC converter, which then outputs a preset DC voltage.

[0009] By controlling and adjusting the voltage values ​​of the high-voltage DC output from the PFC converter or the maximum power point tracking module, priority selection between the two power supplies can be achieved, with the higher voltage supply given priority. After the two inputs are combined, they share the subsequent DC-DC converter, reducing overall system cost, the number of components, and the size of the equipment, resulting in a simpler structure. AC power supply and photovoltaic power supply can achieve zero switching time, which is beneficial for control.

[0010] Furthermore, it also includes a signal processing unit, a first comparator, and a second comparator;

[0011] The signal processing unit is connected to the AC input power supply, the photovoltaic input power supply, the DC / DC converter and the maximum power point tracking module respectively, and collects the voltage information of the AC input power supply and the photovoltaic input power supply.

[0012] The first input terminal of the first comparator is connected to the voltage output terminal of the PFC converter of the signal processing unit, and the second input terminal of the first comparator is connected to an AC input reference value memory.

[0013] The first input terminal of the second comparator is connected to the photovoltaic input power supply voltage output terminal of the signal processing unit, and the second input terminal of the second comparator is connected to a photovoltaic input reference value memory.

[0014] The outputs of the first and second comparators are connected to the output voltage boost control terminal of the maximum power point tracking module via an AND gate, in order to control the output voltage of the maximum power point tracking module to be higher than the output voltage of the PFC converter.

[0015] The output of the second comparator is connected to the output of the first comparator via an AND gate and then to the shutdown control terminal of the maximum power point tracking module.

[0016] The output of the first comparator is connected to the start control terminal of the maximum power point tracking module via an NOT gate, and then to the output of the second comparator via an AND gate, as well as to the stop control terminal of the PFC converter.

[0017] The output of the first comparator is connected to the system shutdown control terminal via an NOT gate, and the output of the second comparator is connected to the NOT gate, and then via an AND gate.

[0018] By using a signal processing unit, a first comparator, a second comparator, and a third comparator, the power supply priority of the maximum power point tracking module and the PFC converter is selected by comparing the corresponding signal magnitudes, which is simple to operate.

[0019] Furthermore, the PFC converter is a bridgeless PFC, which includes a first inductor, a first switch, a second switch, a third switch, a fourth switch, and a first capacitor. The bridgeless PFC is used to convert changing alternating current into stable high-voltage direct current.

[0020] The first switch, the second switch, the third switch, and the fourth switch constitute a soft-switching rectifier circuit;

[0021] One terminal of the AC input power supply is connected to the first input terminal of the rectifier circuit, the first terminal of the first inductor is connected to the other terminal of the AC input power supply, and the second terminal of the first inductor is connected to the second input terminal of the rectifier circuit.

[0022] The first capacitor is connected in parallel to the output of the soft-switching rectifier circuit.

[0023] A bridgeless PFC, consisting of a first inductor, a first switch, a second switch, a third switch, a fourth switch, and a first capacitor, efficiently converts changing alternating current into stable high-voltage direct current.

[0024] Furthermore, the maximum power point tracking module includes a second inductor, a third inductor, a fifth switch, a sixth switch, a first diode, a second diode, a third capacitor, and a fourth capacitor. The maximum power point tracking module is used to convert the changing photovoltaic voltage into a stable high-voltage DC.

[0025] The first end of the third inductor is connected to the positive output terminal of the photovoltaic input power supply, and the second end of the third inductor is connected in series with the first end of the second diode.

[0026] The first end of the second inductor is connected to the first end of the third inductor, the second end of the second inductor is connected in series with the first end of the first diode, and the second end of the first diode is connected to the second end of the second diode.

[0027] The third capacitor is connected between the positive terminal of the photovoltaic input power supply and ground. The two ends of the fifth switch are respectively connected to the second end of the third inductor and the ground of the photovoltaic input power supply. The two ends of the sixth switch are respectively connected to the second end of the second inductor and the ground of the photovoltaic input power supply. The two ends of the fourth capacitor are respectively connected to the second end of the first diode and the ground of the photovoltaic input power supply.

[0028] Photovoltaic input: The maximum power point tracking module consists of a second inductor, a third inductor, a fifth switch, a sixth switch, a first diode, a second diode, a third capacitor, and a fourth capacitor, which efficiently converts the changing photovoltaic voltage into a stable high-voltage DC.

[0029] Furthermore, the DC / DC converter is a primary full-bridge LLC, and includes a seventh switch, an eighth switch, and a second capacitor. The primary full-bridge LLC includes a ninth switch, a tenth switch, an eleventh switch, a twelfth switch, a resonant capacitor (Cr), a resonant inductor (Lr), a magnetizing inductor (Lm), and a transformer (T1). The seventh switch, the eighth switch, and the second capacitor provide synchronous rectification on the secondary side. The DC / DC converter is used to efficiently convert high-voltage DC power into the target DC voltage output.

[0030] The ninth switch and the eleventh switch are connected in series, the tenth switch and the twelfth switch are connected in series, and the ninth switch and the eleventh switch are simultaneously connected in parallel with the tenth switch and the twelfth switch.

[0031] One end of Cr is connected in series with Lr, and the other end is connected to the middle line between the tenth and twelfth switches. One end of Lm is connected to the end of Lr furthest from Cr, and the other end is connected to the middle line between the ninth and eleventh switches.

[0032] T1 is connected in parallel with Lm, and the seventh and eighth switches are connected in parallel and then connected to the second capacitor.

[0033] The primary full-bridge LLC is composed of the ninth, tenth, eleventh, and twelfth switches, Cr, Lr, Lm, and T1. The secondary synchronous rectifier consists of the seventh and eighth switches and the second capacitor, which efficiently converts the high-voltage DC power into the target DC voltage output.

[0034] Furthermore, it also includes a communication interface, which is connected to a signal processing unit or a comparator.

[0035] Configure a communication interface to connect to external devices.

[0036] Furthermore, it also includes a status display module, which is connected to a signal processing unit or a comparator.

[0037] The status display module shows whether the device is working properly, making it easy to check. Attached Figure Description

[0038] Figure 1 This is a structural block diagram of the multi-type input integrated power supply system of this utility model;

[0039] Figure 2 This is a schematic diagram of the structure of the multi-type input integrated power supply system of this utility model. Detailed Implementation

[0040] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0041] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0042] In the description of this utility model, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0043] This utility model discloses a multi-type input integrated power supply system, such as Figure 1 and Figure 2 As shown, it includes a PFC converter, a maximum power point tracking module, and a DC / DC converter.

[0044] The output of the AC input power supply is electrically connected to the PFC converter (PFC), the output of the photovoltaic input power supply is electrically connected to the maximum power point tracking module (MPPT DC / DC), and the outputs of the PFC converter and the maximum power point tracking module are connected in parallel and then electrically connected to the DC / DC converter (DC / DC).

[0045] The input is powered by both AC and photovoltaic DC power. The AC input power is rectified and then outputs a stable high-voltage DC through a PFC converter. The photovoltaic input power is output a stable high-voltage DC after passing through a maximum power point tracking module. The two high-voltage DC power sources are combined to power the DC-DC converter, which then outputs a preset DC voltage.

[0046] By controlling and adjusting the voltage values ​​of the high-voltage DC output from the PFC converter or the maximum power point tracking module, priority selection between the two power supplies can be achieved, with the higher voltage supply given priority. After the two inputs are combined, they share the subsequent DC-DC converter, reducing the overall system cost, the number of components, and the size of the equipment, resulting in a simpler structure. AC power supply and photovoltaic power supply can achieve zero switching time.

[0047] In a preferred embodiment of this utility model, the multi-type input integrated power supply system further includes a signal processing unit (such as a voltage sensor (such as a MIK-DZV single-phase DC voltage sensor, etc.) and a power sensor (such as a Hongke power sensor, etc.), a first comparator, a second comparator, and a third comparator. In this utility model, the comparators can be digital comparators or analog comparators. As needed, the input terminals of each comparator can receive the signal values ​​through a digital-to-analog converter. The comparators are preferably, but not limited to, LM324 and LM339, and the comparators are placed inside the MCU.

[0048] The signal processing unit is electrically connected to the AC input power supply, the photovoltaic input power supply, the DC / DC converter, and the maximum power point tracking module, respectively, and collects the voltage information (V) of the AC input power supply and the photovoltaic input power supply. AC-f and V PV-f ), the maximum power of the DC / DC converter (P) OUT-MAX ), and the maximum power (P) of the maximum power point tracking module. MPPT-MAX ).

[0049] The first input terminal of the first comparator is electrically connected to the voltage output terminal of the PFC converter of the signal processing unit, and the second input terminal of the first comparator is electrically connected to an AC input reference value (V). ref-AC ) memory.

[0050] The first input terminal of the second comparator is electrically connected to the output terminal of the photovoltaic input power supply voltage of the signal processing unit, and the second input terminal of the second comparator is electrically connected to the photovoltaic input reference value (V). ref-PV ) memory.

[0051] The first input terminal of the third comparator is electrically connected to the maximum power output terminal of the DC / DC converter of the signal processing unit, and the second input terminal of the third comparator is electrically connected to the maximum power point output terminal of the maximum power point tracking module of the signal processing unit.

[0052] The outputs of the first and second comparators are electrically connected to the output voltage boost control terminal of the maximum power point tracking module via an AND gate. (The output voltage is adjusted by changing the ratio of the output reference voltage or feedback voltage. For example, the outputs of the first and second comparators can be connected to the input of a digital-to-analog converter (DAC) via an AND gate, and the DAC outputs a reference voltage.) This is used to control the output voltage of the maximum power point tracking module to be higher than the output voltage of the PFC converter; that is, V AC-f >V ref-AC V PV-f >V ref-PV (P) MPPT-MAX >P OUT-MAX or P MPPT-MAX <P OUT-MAX This indicates that the AC input is powered, the photovoltaic input has sufficient power or insufficient photovoltaic input power. At this time, the AND gate outputs a control signal to control the output voltage of the maximum power point tracking module to increase.

[0053] The output of the second comparator, after passing through an NOT gate, is then connected to the output of the first comparator via an AND gate, and finally electrically connected to the shutdown control terminal of the maximum power point tracking module. That is, V AC-f >V ref-AC V PV-f <V ref-pv This indicates that the AC input is powered, but there is no photovoltaic input. The maximum power point tracking module is turned off, and the AC input is under load.

[0054] The output of the first comparator, after passing through an NOT gate, is then connected to the output of the second comparator via an AND gate, and finally electrically connected to the start control terminal of the maximum power point tracking module, and also electrically connected to the stop control terminal of the PFC converter. That is, V AC-f <V ref-AC V PV-f >V ref-pv If the signal indicates that there is no power at the AC input and the photovoltaic input has sufficient power, then the PFC converter should be shut down.

[0055] The output of the first comparator is connected to the system shutdown control terminal via an NOT gate, and the output of the second comparator is also connected to the NOT gate, then to the AND gate. That is, V AC-f <V ref-AC V PV-f <V ref-pv If the AC input and photovoltaic input are both without power, the system will shut down.

[0056] It should be noted that the shutdown control terminal of the maximum power point tracking module, the startup control terminal of the maximum power point tracking module, and the system shutdown control terminal are not shown in the figure. Their specific locations can be found using conventional design.

[0057] In a preferred embodiment of this utility model, the PFC converter is a bridgeless PFC, which includes a first inductor (L1), a first switch (Q1), a second switch (Q2), a third switch (Q3), a fourth switch (Q4), and a first capacitor (C1). The bridgeless PFC is used to convert changing alternating current into stable high-voltage direct current.

[0058] The first switch, the second switch, the third switch, and the fourth switch constitute a soft-switching rectifier circuit. One pole of the AC input power supply is electrically connected to the first input terminal of the rectifier circuit. The first end of the first inductor is electrically connected to the other pole of the AC input power supply. The second end of the first inductor is electrically connected to the second input terminal of the rectifier circuit. The first capacitor is connected in parallel to the output terminal of the soft-switching rectifier circuit.

[0059] A bridgeless PFC, consisting of a first inductor, a first switch, a second switch, a third switch, a fourth switch, and a first capacitor, efficiently converts changing alternating current into stable high-voltage direct current.

[0060] In a preferred embodiment of this utility model, the maximum power point tracking module (interleaved BOOST) includes a second inductor (L2), a third inductor (L3), a fifth switch (Q5), a sixth switch (Q6), a first diode (D1), a second diode (D2), a third capacitor (C3), and a fourth capacitor (C4). The maximum power point tracking module is used to convert the changing photovoltaic voltage into a stable high-voltage DC.

[0061] The first terminal of the third inductor is electrically connected to the positive output terminal of the photovoltaic input power supply, and the second terminal of the third inductor is connected in series with the first terminal of the second diode. The first terminal of the second inductor is electrically connected to the first terminal of the third inductor, and the second terminal of the second inductor is connected in series with the first terminal of the first diode. The second terminal of the first diode is electrically connected to the second terminal of the second diode.

[0062] The third capacitor is connected between the positive terminal of the photovoltaic input power supply and ground. The two ends of the fifth switch are respectively connected to the second end of the third inductor and the ground of the photovoltaic input power supply. The two ends of the sixth switch are respectively connected to the second end of the second inductor and the ground of the photovoltaic input power supply. The two ends of the fourth capacitor are respectively connected to the second end of the first diode and the ground of the photovoltaic input power supply.

[0063] Photovoltaic input: The maximum power point tracking module consists of a second inductor, a third inductor, a fifth switch, a sixth switch, a first diode, a second diode, a third capacitor, and a fourth capacitor, which efficiently converts the changing photovoltaic voltage into a stable high-voltage DC.

[0064] In a preferred embodiment of this utility model, the DC / DC converter is a primary full-bridge LLC, and includes a seventh switch (Q7), an eighth switch (Q8), and a second capacitor (C2). The primary full-bridge LLC includes a ninth switch (Q9), a tenth switch (Q10), an eleventh switch (Q11), a twelfth switch (Q12), a resonant capacitor (Cr), a resonant inductor (Lr), a magnetizing inductor (Lm), and a transformer (T1). The seventh switch, the eighth switch, and the second capacitor provide synchronous rectification on the secondary side. The DC / DC converter is used to efficiently convert high-voltage DC power into a target DC voltage output.

[0065] The ninth and eleventh switches are connected in series, the tenth and twelfth switches are connected in series, and the ninth and eleventh switches are simultaneously connected in parallel with the tenth and twelfth switches.

[0066] One end of Cr is connected in series with Lr, and the other end is connected to the middle line between the tenth and twelfth switches. One end of Lm is connected to the end of Lr furthest from Cr, and the other end is connected to the middle line between the ninth and eleventh switches. T1 is connected in parallel with Lm, and the seventh and eighth switches are connected in parallel and then connected to the second capacitor.

[0067] The primary full-bridge LLC is composed of the ninth, tenth, eleventh, and twelfth switches, Cr, Lr, Lm, and T1. The secondary synchronous rectifier consists of the seventh and eighth switches and the second capacitor, which efficiently converts the high-voltage DC power into the target DC voltage output.

[0068] In a preferred embodiment of this utility model, the multi-type input integrated power supply system further includes a communication interface, which (such as an RS485 interface) is electrically connected to a signal processing unit or comparator. The communication interface is provided to connect to external devices.

[0069] In a preferred embodiment of this utility model, the multi-type input integrated power supply system further includes a status display module (such as LED lights, lamp groups, etc.), which is electrically connected to the signal processing unit or comparator. When the device is powered on, the status display module lights up. The status display module indicates whether the device is working properly, making it easy to check.

[0070] It should be noted that the first switch (Q1), the second switch (Q2), the third switch (Q3), the fourth switch (Q4), the fifth switch (Q5), the sixth switch (Q6), the seventh switch (Q7), the eighth switch (Q8), the ninth switch (Q9), the tenth switch (Q10), the eleventh switch (Q11), and the twelfth switch (Q12) can be controlled using existing technologies, and are not the innovation of this utility model, so they will not be elaborated here.

[0071] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0072] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A multi-type input integrated power supply system, characterized in that, The PFC converter, the maximum power point tracking module and the DC / DC converter are included. The output end of the AC input power supply is connected with the PFC converter, and the output end of the photovoltaic input power supply is connected with the maximum power point tracking module. The signal processing unit, the first comparator and the second comparator are further included. The signal processing unit is connected with the AC input power supply, the photovoltaic input power supply, the DC / DC converter and the maximum power point tracking module respectively, and the voltage information of the AC input power supply and the photovoltaic input power supply is collected. The first input end of the first comparator is connected with the PFC converter voltage output end of the signal processing unit, and the second input end of the first comparator is connected with the AC input reference value storage. The first input end of the second comparator is connected with the photovoltaic input power supply voltage output end of the signal processing unit, and the second input end of the second comparator is connected with the photovoltaic input reference value storage. The output ends of the first comparator and the second comparator are connected with the output voltage high control end of the maximum power point tracking module through an AND gate, so as to control the output voltage of the maximum power point tracking module to be higher than the output voltage of the PFC converter. The output end of the second comparator is connected with the closing control end of the maximum power point tracking module through an inverter and an AND gate. The output end of the first comparator is connected with the starting control end of the maximum power point tracking module and the stop control end of the PFC converter through an inverter and an AND gate. The output ends of the first comparator and the second comparator are connected with the system shutdown control end through an inverter and an AND gate.

2. The multi-type input integrated power supply system according to claim 1, wherein The PFC converter is a bridgeless PFC, which includes a first inductor, a first switch, a second switch, a third switch, a fourth switch and a first capacitor. The first switch, the second switch, the third switch and the fourth switch constitute a soft switching rectifier circuit. One pole of the AC input power supply is connected with the first input end of the rectifier circuit, the first end of the first inductor is connected with the other pole of the AC input power supply, and the second end of the first inductor is connected with the second input end of the rectifier circuit. The first capacitor is connected in parallel at the output end of the soft switching rectifier circuit.

3. The multi-type input integrated power supply system according to claim 1, wherein The maximum power point tracking module includes a second inductor, a third inductor, a fifth switch, a sixth switch, a first diode, a second diode, a third capacitor and a fourth capacitor. The first end of the third inductor is connected with the positive output end of the photovoltaic input power supply, and the second end of the third inductor is connected with the first end of the second diode in series. The first end of the second inductor is connected with the first end of the third inductor, the second end of the second inductor is connected with the first end of the first diode in series, and the second end of the first diode is connected with the second end of the second diode. The third capacitor is connected between the positive pole of the photovoltaic input power supply and the ground, the fifth switch is connected between the second end of the third inductor and the ground of the photovoltaic input power supply, the sixth switch is connected between the second end of the second inductor and the ground of the photovoltaic input power supply, and the second end of the fourth capacitor is connected to the second end of the first diode and the ground of the photovoltaic input power supply.

4. The multi-type input integrated power supply system according to claim 1, wherein The DC / DC converter is a primary full-bridge LLC, and the seventh switch, the eighth switch, and the second capacitor are secondary synchronous rectification, the DC / DC converter is used for converting high-voltage direct current into target direct current voltage output efficiently; The ninth switch and the eleventh switch are connected in series, the tenth switch and the twelfth switch are connected in series, and the ninth switch and the eleventh switch are connected in parallel with the tenth switch and the twelfth switch at the same time; One end of the resonant capacitor (Cr) is connected in series with the resonant inductor (Lr), and the other end is connected to the middle connection line of the tenth switch and the twelfth switch, one end of the excitation inductor (Lm) is connected to the end of the resonant inductor (Lr) away from the resonant capacitor (Cr), and the other end is connected to the middle connection line of the ninth switch and the eleventh switch; The transformer (T1) is connected in parallel with the excitation inductor (Lm), and the seventh switch and the eighth switch are connected in parallel and then connected to the second capacitor.

5. The multi-type input integrated power supply system according to claim 1, wherein The communication interface is connected with the signal processing unit or the comparator.

6. The multi-type input integrated power supply system according to claim 1, wherein The state display module is connected with the signal processing unit or the comparator.

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