A multi-port DC-DC converter suitable for 5G base stations

Abstract

A multi-port DC-DC converter suitable for 5G base stations, the converter includes: 3 inductors L1, L2, L3, 3 capacitors C1, C2, C3, 2 diodes D1, D2 and 3 switches S1, S2, S3. When the sunlight energy is appropriate, the photovoltaic panel supplies power to the load alone; when the sunlight energy is excessive, the photovoltaic panel supplies power to the battery and the load together; when the sunlight energy is insufficient, the battery and the photovoltaic panel supply power to the load together; when there is no sunlight, the battery supplies power to the load alone. The entire converter can be switched to different modes according to different working conditions. At the same time, since the proposed converter adopts a non-isolated structure and has a small number of components, the system efficiency is improved while the system cost is greatly reduced; the addition of the battery overcomes the problems of intermittent photovoltaic power generation and unsatisfactory power supply reliability, and fully utilizes green energy to solve the problem of power supply for 5G base stations.

Description

Technical Field

[0001] The present invention relates to a multi-port DC-DC converter, in particular to a multi-port DC-DC converter suitable for a 5G base station. Background Art

[0002] As the scale of 5G construction expands, the power supply requirements of 5G base stations are getting higher and higher. It is estimated that the power consumption of a single 5G base station is 2.5 to 3.5 times that of a 4G base station. Therefore, in order to ensure the power supply quality of the base station, the power supply plan and power supply technology of the base station have become the focus of research.

[0003] In the existing technology, the power supply scheme of 5G base stations is as follows: Figure 1 and Figure 2 shown. Figure 1 The solution takes power from the large power grid, which is first inverted to 400V and then stepped down to 48V for base station loads. Figure 2 The solution is to generate electricity through a photovoltaic storage system and then convert it into electrical energy. In the process of multi-level energy conversion, they reduce the efficiency of the system, increase the cost of the system, and also increase the complexity of the system.

[0004] The basic boost circuit also has a certain boost capability. However, boost is a single-input structure. The uncertainty and intermittency of solar input will cause unstable power supply quality. In order to achieve green energy generation while improving system efficiency, reliability and power supply quality, multi-port power supply technology has become a research hotspot. Summary of the invention

[0005] The purpose of the present invention is to provide a multi-port DC-DC converter suitable for a 5G base station, which ensures the power supply quality and system efficiency of the system; at the same time, the DC-DC converter has a simple circuit structure and fewer components, which greatly reduces the cost of the system.

[0006] The technical solution adopted by the present invention is:

[0007] A multi-port DC-DC converter suitable for a 5G base station, the converter comprising:

[0008] Switches S1, S2, S3, inductors L1, L2, L3, capacitors C1, C2, C3, diodes D1, D2;

[0009] One end of the inductor L1 is connected to the positive electrode of the power module, and the other end of the inductor L1 is respectively connected to the drain of the switch tube S1 and one end of the capacitor C3; the other end of the capacitor C3 is respectively connected to the drain of the switch tube S2, one end of the inductor L3, and the anode of the diode D2; the cathode of the diode D2 is connected to one end of the capacitor C1;

[0010] The negative electrode of the power module is respectively connected to the drain source of the switch tube S1, the other end of the inductor L3, and the other end of the capacitor C1;

[0011] The source of the switch tube S2 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the drain of the switch tube S3 and the positive electrode of the battery, and the negative electrode of the battery is grounded;

[0012] The source of the switch tube S3 is connected to one end of the inductor L2 and the cathode of the diode D3 respectively, the other end of the inductor L2 is connected to the other end of the capacitor C1 and one end of the capacitor C2 respectively, and the other end of the capacitor C2 is connected to the anode of the diode D3;

[0013] One end of the capacitor C1 and the other end of the capacitor C2 are connected to the positive electrode and the negative electrode of the base station load bus respectively.

[0014] When the currents of the inductors L1, L2, and L3 are continuously conducting, the converter can switch between four working modes by changing the duty cycle of the switching tubes according to the different states of the power switches S1, S2, and S3, which are:

[0015] When the solar energy is appropriate, the electricity generated by the photovoltaic panels will be used to power the base station alone;

[0016] When solar energy is not working, the battery alone supplies power to the base station;

[0017] When there is sufficient solar energy, the electricity generated by the photovoltaic panels can be used to power the base station and charge the battery.

[0018] When solar energy is insufficient, batteries and photovoltaic panels together supply power to the base station load.

[0019] The present invention provides a multi-port DC-DC converter suitable for a 5G base station, and the technical effects are as follows:

[0020] 1) The converter of the present invention can be switched to different modes according to different working conditions. At the same time, since the proposed converter adopts a non-isolated structure and has a small number of components, the system efficiency is improved while the system cost is greatly reduced.

[0021] 2) The addition of the converter battery of the present invention overcomes the problems of intermittent photovoltaic power generation and unsatisfactory power supply reliability, and fully utilizes green energy to solve the problem of power supply for 5G base stations. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of a commonly used 5G base station power supply solution 1 that draws power from the mains.

[0023] Figure 2 This is a schematic diagram of a commonly used 5G base station power supply solution 2 for distributed energy.

[0024] Figure 3 This is a circuit diagram of a multi-port DC-DC converter proposed by the present invention.

[0025] FIG4 (1) is a waveform diagram of the input voltage and output voltage of the switch tube S1 when the photovoltaic panel is the only power supply;

[0026] FIG4 (2) is a voltage waveform diagram of capacitor C3 and diode D2 when the photovoltaic panel is used for power supply alone;

[0027] FIG4(3) is a diagram showing the current waveforms of the inductors L1, L2, and L3 when the photovoltaic panel is used alone for power supply.

[0028] FIG5 (1) is a voltage waveform diagram of the switch tubes S1, S3, input and output when the battery is used as the sole power supply;

[0029] FIG5(2) is a voltage waveform diagram of diode D3 when powered by a battery alone;

[0030] FIG5(3) is a current waveform diagram of the inductor L2 and the output current when the battery is the only power supply.

[0031] FIG6 (1) is a voltage waveform diagram of the switch tubes S1 and S3 when the photovoltaic and battery power supply is combined;

[0032] FIG6 (2) is a waveform diagram of photovoltaic input, battery input and output voltages when photovoltaic and battery are used for power supply;

[0033] Figure 6 (3) is a waveform diagram of the output voltages of capacitors C1, C2, and C3 when powered by photovoltaic and battery.

[0034] Figure 6 (4) is a waveform diagram of the output voltage of diodes D2 and D3 when powered by photovoltaic and battery.

[0035] FIG7 (1) is a voltage waveform diagram of the switch tubes S1 and S3 when the photovoltaic power supply is supplied to the battery and the load together;

[0036] Figure 7 (2) is a waveform diagram of the output voltage of capacitors C1, C3, diodes D1, D2 when photovoltaic power is supplied to the battery and the load together;

[0037] Figure 7(3) is a waveform diagram of the inductors L1, L3, output current and battery charging current when photovoltaic power is supplied to the battery and the load together. DETAILED DESCRIPTION

[0038] like Figure 3 As shown, a multi-port DC-DC converter suitable for a 5G base station includes: switch tubes S1, S2, S3, inductors L1, L2, L3, capacitors C1, C2, C3, diodes D1, D2;

[0039] One end of the inductor L1 is connected to the positive electrode of the power module, and the other end of the inductor L1 is respectively connected to the drain of the switch tube S1 and one end of the capacitor C3; the other end of the capacitor C3 is respectively connected to the drain of the switch tube S2, one end of the inductor L3, and the anode of the diode D2; the cathode of the diode D2 is connected to one end of the capacitor C1;

[0040] The negative electrode of the power module is respectively connected to the drain source of the switch tube S1, the other end of the inductor L3, and the other end of the capacitor C1;

[0041] The source of the switch tube S2 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the drain of the switch tube S3 and the positive electrode of the battery respectively, and the negative electrode of the battery is grounded;

[0042] The source of the switch tube S3 is connected to one end of the inductor L2 and the cathode of the diode D3 respectively, the other end of the inductor L2 is connected to the other end of the capacitor C1 and one end of the capacitor C2 respectively, and the other end of the capacitor C2 is connected to the anode of the diode D3;

[0043] One end of the capacitor C1 and the other end of the capacitor C2 are connected to the positive electrode and the negative electrode of the base station load bus respectively.

[0044] When the currents of the inductors L1, L2, and L3 of the proposed multi-port DC-DC converter are continuously turned on, the circuit can be divided into four working modes according to the different states of the power switches S1, S2, and S3, which are:

[0045] Photovoltaic panels alone provide power to the base station SISOA;

[0046] The battery alone supplies power to the base station SISOB;

[0047] Photovoltaic panels and batteries together provide power to the base station DISO;

[0048] Photovoltaic panels supply power to batteries and base stations SIDO;

[0049] When the output voltage of the photovoltaic panel is 36V, the output voltage of the battery is 38V, the base station load voltage is 48V, and the power is 200W, the following four working conditions are analyzed one by one:

[0050] In the following formulas (1) to (16), D1, D2, and D3 represent the duty ratios of switches 1, 2, and 3; U B Indicates battery voltage, U pv Indicates the output voltage of the photovoltaic panel; U C Represents the voltage across the capacitor, U0 represents the output voltage U D , represents the voltage of the diode; U s Represents the voltage between the drain and source of the switch tube; I L ,I0,I D They represent the inductor current, output current and diode current respectively.

[0051] Working condition 1:

[0052] When the converter works in the mode where the photovoltaic panel supplies power to the base station alone, the duty cycle is 0.571. S When switch S1 is turned on, diode D2 is turned off, capacitors C1 and C3 are discharged, and inductors L1 and L3 are charged; when switch S1 is turned off, diode D2 is turned on, capacitors C1 and C3 are charged, and inductors L1 and L3 are discharged. Based on this, the inductor volt-second balance and ampere-second balance can be listed as follows:

[0053]

[0054]

[0055] The voltage stress and current stress in this mode are as follows:

[0056]

[0057]

[0058] The waveform in this mode is as follows Figure 4(1) to Figure 4(3) As shown. Figure 4(1) to Figure 4(3) It can be seen that the waveform obtained by simulation is completely consistent with equations (3) to (4) corresponding to the theoretical analysis.

[0059] Working condition 2:

[0060] When the converter works in the mode where the battery alone supplies power to the base station, the duty cycle is 0.56. S When switch S3 is turned on, diode D3 is turned off, inductor L2 is charged, and capacitor C2 is discharged; when switch S3 is turned off, diode D3 is turned on, inductor L2 is discharged, and capacitor C2 is charged. Writing volt-second balance and ampere-second balance gives:

[0061]

[0062]

[0063] The voltage stress and current stress in this mode are as follows:

[0064]

[0065]

[0066] The waveform obtained in this mode is as follows Figure 5(1) to Figure 5(3) As shown. Figure 5(1) to Figure 5(3) It can be seen that the waveform obtained by simulation is completely consistent with equations (7) to (8) corresponding to the theoretical analysis.

[0067] Working condition three:

[0068] When the converter works in the mode where the photovoltaic panel and the battery together supply power to the base station, the duty cycle D1 is 0.4, D3 is 0.395, and in one switching cycle T S In the circuit, when the switch tube S1 is turned on and S3 is turned off, the diodes D1 and D2 are turned off and the diode D3 is turned on. The inductors L1 and L3 are charged and L2 is discharged. The capacitors C1 and C3 are discharged and C2 is charged. When the switch tubes S1 and S3 are turned on at the same time, the diodes D2 and D3 are turned on, the inductors L1, L2 and L3 are charged and the capacitors C1, C2 and C3 are discharged. When the switch tubes S1 and S3 are turned off, the capacitors C1, C2 and C3 are charged and the inductors L1, L2 and L3 are discharged. By writing the volt-second balance and ampere-second balance, we can get

[0069]

[0070]

[0071]

[0072] The voltage stress and current are:

[0073]

[0074]

[0075] The waveform obtained in this mode is as follows Figure 6(1) to Figure 6(4) As shown. Figure 6(1) to Figure 6(4) It can be seen that the waveform obtained by simulation is completely consistent with equations (11) to (12) corresponding to the theoretical analysis.

[0076] Working condition 4:

[0077] When the converter works in the mode where the photovoltaic panel supplies power to the battery and the base station, the duty cycle D1 is 0.551 and D2 is 0.174.

[0078] In a switching cycle T S In the circuit, when the switch tube S1 is turned on and S2 is turned off, the diodes D1 and D2 are turned off, the diode D3 is turned on, the capacitors C1 and C3 are discharged, and the inductors L1 and L3 are charged; when the switch tube S1 is turned off and S2 is turned on, the diodes D1 and D3 are turned on and D2 is turned off, the capacitor C3 is charged, C1 is discharged, and the inductor L3 is discharged; when the switch tubes S1 and S2 are turned off, the inductors L1 and L3 are discharged, the diodes D2 and D3 are turned on, and the capacitors C1 and C3 are charged. By writing the volt-second balance and ampere-second balance, we can get:

[0079]

[0080]

[0081] The device voltage stress and current are obtained as:

[0082]

[0083]

[0084] The waveform obtained in this mode is as follows Figure 7(1) to Figure 7(3) As shown. Figure 7(1) to Figure 7(3) It can be seen that the waveform obtained by simulation is completely consistent with equations (15) to (16) corresponding to the theoretical analysis.

Claims

1. A multi-port DC-DC converter suitable for 5G base stations, characterized in that: The converter includes: Switches S1, S2, S3, inductors L1, L2, L3, capacitors C1, C2, C3, diodes D1, D2; One end of the inductor L1 is connected to the positive electrode of the power module, and the other end of the inductor L1 is respectively connected to the drain of the switch tube S1 and one end of the capacitor C3; the other end of the capacitor C3 is respectively connected to the drain of the switch tube S2, one end of the inductor L3, and the anode of the diode D2; the cathode of the diode D2 is connected to one end of the capacitor C1; The negative electrode of the power module is respectively connected to the drain source of the switch tube S1, the other end of the inductor L3, and the other end of the capacitor C1; The source of the switch tube S2 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the drain of the switch tube S3 and the positive electrode of the battery, and the negative electrode of the battery is grounded; The source of the switch tube S3 is connected to one end of the inductor L2 and the cathode of the diode D3 respectively, the other end of the inductor L2 is connected to the other end of the capacitor C1 and one end of the capacitor C2 respectively, and the other end of the capacitor C2 is connected to the anode of the diode D3; One end of capacitor C1 and the other end of capacitor C2 are connected to the positive electrode and negative electrode of the base station load bus respectively; When the converter works in the mode where the photovoltaic panel alone supplies power to the base station, in a switching cycle T S When switch S1 is turned on, diode D2 is turned off, capacitors C1 and C3 are discharged, and inductors L1 and L3 are charged; when switch S1 is turned off, diode D2 is turned on, capacitors C1 and C3 are charged, and inductors L1 and L3 are discharged; based on this, the inductor volt-second balance and ampere-second balance can be listed as follows: The voltage stress and current stress in this mode are as follows: When the converter works in the mode where the battery alone supplies power to the base station, in a switching cycle T S When switch S3 is turned on, diode D3 is turned off, inductor L2 is charged, and capacitor C2 is discharged; when switch S3 is turned off, diode D3 is turned on, inductor L2 is discharged, and capacitor C2 is charged; writing volt-second balance and ampere-second balance for it, we can get: The voltage stress and current stress in this mode are as follows: When the converter works in the mode where the photovoltaic panel and the battery together supply power to the base station, in a switching cycle T S When the switch tube S1 is turned on and S3 is turned off, the diodes D1 and D2 are turned off and the diode D3 is turned on. The inductors L1 and L3 are charged and L2 is discharged. The capacitors C1 and C3 are discharged and C2 is charged. When the switch tubes S1 and S3 are turned on at the same time, the diodes D2 and D3 are turned on, the inductors L1, L2 and L3 are charged and the capacitors C1, C2 and C3 are discharged. When the switch tubes S1 and S3 are turned off, the capacitors C1, C2 and C3 are charged and the inductors L1, L2 and L3 are discharged. By writing the volt-second balance and ampere-second balance, we can get: The voltage stress and current are When the converter works in the mode where the photovoltaic panel supplies power to the battery and the base station together, in a switching cycle T S In the circuit, when the switch tube S1 is turned on and S2 is turned off, the diodes D1 and D2 are turned off, the diode D3 is turned on, the capacitors C1 and C3 are discharged, and the inductors L1 and L3 are charged; when the switch tube S1 is turned off and S2 is turned on, the diodes D1 and D3 are turned on and D2 is turned off, the capacitor C3 is charged, C1 is discharged, and the inductor L3 is discharged; when the switch tubes S1 and S2 are turned off, the inductors L1 and L3 are discharged, the diodes D2 and D3 are turned on, and the capacitors C1 and C3 are charged. By writing the volt-second balance and ampere-second balance, we can get: The device voltage stress and current are obtained as 2. A multi-port DC-DC converter suitable for a 5G base station according to claim 1, characterized in that: When the currents of the inductors L1, L2, and L3 are continuously conducting, the converter can switch between four working modes by changing the duty cycle of the switching tubes according to the different states of the power switches S1, S2, and S3, which are: When the solar energy is appropriate, the electricity generated by the photovoltaic panels will be used to power the base station alone; When solar energy is not working, the battery alone supplies power to the base station; When there is sufficient solar energy, the electricity generated by the photovoltaic panels can be used to power the base station and charge the battery. When solar energy is insufficient, batteries and photovoltaic panels together supply power to the base station load.

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