阅读说明：本技术 一种正负双向开关电源的功率变换装置及控制方法 (Power conversion device and control method of positive and negative bidirectional switching power supply ) 是由 徐魁 赵伟星 马超 毛亚胜 于 2020-03-25 设计创作，主要内容包括：本发明公开了一种正负双向开关电源的功率变换装置,包括功率变换单元、控制单元、可充放电储能单元一、可充放电储能单元二；功率变换单元分别连接可充放电储能单元一、可充放电储能单元二,控制单元分别连接控制功率变换单元、可充放电储能单元一、可充放电储能单元二。本装置和方法,可以一体化的实现隔离型正负输出双向传递开关电源的功率变换功能,不需要多台设备相互连接来实现这些功能；进而大幅度降低设备体积,有效的降低成本,本发明还可以提供更高的功率转换效率,起到节能的效果。(The invention discloses a power conversion device of a positive and negative bidirectional switching power supply, which comprises a power conversion unit, a control unit, a first chargeable and dischargeable energy storage unit and a second chargeable and dischargeable energy storage unit, wherein the first chargeable and dischargeable energy storage unit is connected with the second chargeable and dischargeable energy storage unit; the power conversion unit is respectively connected with the first chargeable and dischargeable energy storage unit and the second chargeable and dischargeable energy storage unit, and the control unit is respectively connected with and controls the power conversion unit, the first chargeable and dischargeable energy storage unit and the second chargeable and dischargeable energy storage unit. The device and the method can integrally realize the power conversion function of the isolated positive and negative output bidirectional transfer switching power supply, and do not need to connect a plurality of devices to realize the functions; the invention can provide higher power conversion efficiency and has the effect of energy saving.)

1. A power conversion device of a positive-negative bidirectional switching power supply is characterized by comprising a power conversion unit (1), a control unit (2), a first chargeable and dischargeable energy storage unit (3) and a second chargeable and dischargeable energy storage unit (4); the power conversion unit (1) is respectively connected with the first chargeable and dischargeable energy storage unit (3) and the second chargeable and dischargeable energy storage unit (4), and the control unit is respectively connected with and controls the power conversion unit (1), the first chargeable and dischargeable energy storage unit (3) and the second chargeable and dischargeable energy storage unit (4).

2. The power conversion device of the positive-negative bidirectional switching power supply according to claim 1, wherein the power conversion unit (1) comprises a first capacitor C1(5), a second capacitor C2(8), a third capacitor C3(9), a fourth capacitor C4(16), a first switch tube Q1(6), a second switch tube Q2(7), a third switch tube Q3(11), a fourth switch tube Q4(12), a fifth switch tube Q5(13), a sixth switch tube Q6(14), an energy storage inductor L1 (15), and a transformer T1 (10);

one end of the energy storage inductor L1 is connected with a fourth capacitor C4, and the network is defined as V2;

the other end of the energy storage inductor L1 is connected with one end of a third switching tube Q3 and a PIN4 of a transformer T1, and a network is defined as V3;

the other end of the fourth capacitor C4 is commonly connected with a sixth switching tube Q6 and a fourth switching tube Q4, and the network is defined as GND 2;

the other end of the sixth switching tube Q6 is connected with one end of the fifth switching tube Q5;

the other end of the fifth switching tube Q5 is connected with PIN5 of the transformer T1;

the other end of the fourth switching tube Q4 is connected with one end of a third switching tube Q3;

the other end of the third switching tube Q3 is connected with PIN3 of the transformer T1;

one end of the first capacitor C1 is commonly connected with the first switch tube Q1 and the second capacitor C2, and the network is defined as V1;

the other end of the first capacitor C1 is commonly connected with the second switch tube Q2 and the third capacitor C3, and the network is defined as GND 1; the other end of the first switch tube Q1 is connected with the other end of the second switch tube Q2;

the other end of the second capacitor C2 is connected with the other end of the third capacitor C3;

the control end of the first switch tube Q1, the control end of the second switch tube Q2, the control end of the third switch tube Q3, the control end of the fourth switch tube Q4, the control end of the fifth switch tube Q5 and the control end of the sixth switch tube Q6 are respectively connected to the control unit (2);

the control unit (2) detects the voltage between V1 and GND1, the voltage between V2 and GND2, and the current I _ L1 of the energy storage inductor L1.

3. The power conversion device of a positive-negative bidirectional switching power supply according to claim 1, wherein the first chargeable/dischargeable energy storage unit (3) is a chargeable/dischargeable energy storage device.

4. The power conversion device of the positive-negative bidirectional switching power supply as claimed in claim 1, wherein the second chargeable/dischargeable energy storage unit (4) is a chargeable/dischargeable energy storage device.

5. A control method of a power conversion device of a switching power supply is characterized in that when the voltage of V2 is positive relative to GND2 and a secondary rechargeable energy storage unit (4) needs to be charged positively, a control unit (2) controls a power conversion unit (2) to enable the average current I _ L1 of an energy storage inductor L1 (15) to flow from a network V3 to a network V2, the primary charging of the secondary rechargeable energy storage unit (4) in the positive direction in a first quadrant is completed, and at the moment, the primary rechargeable energy storage unit (3) serves as a power supply to discharge to the power conversion unit (1);

when the voltage of the V2 is positive relative to the GND2 and the secondary rechargeable energy storage unit (4) needs to be discharged in the forward direction, the control unit (2) controls the power conversion unit (2) to enable the average current I _ L1 of the energy storage inductor L1 (15) to flow from the network V2 to the network V3, so that the forward discharge of the secondary rechargeable energy storage unit (4) in the fourth quadrant is completed, and at the moment, the primary rechargeable energy storage unit (3) serves as an energy storage load and is charged by the power conversion unit (1);

when the voltage of the V2 is negative relative to the GND2 and the secondary chargeable and dischargeable energy storage unit (4) needs to be charged negatively, the control unit (2) controls the power conversion unit (2) to enable the average current I _ L1 of the energy storage inductor L1 (15) to flow from the network V2 to the network V3, so that the secondary chargeable and dischargeable energy storage unit (4) is charged negatively in the third quadrant, and at the moment, the primary chargeable and dischargeable energy storage unit (3) serves as a power supply to discharge to the power conversion unit (1);

when the voltage of V2 is negative relative to GND2 and negative-going discharge of the second chargeable and dischargeable energy storage unit (4) is required, the control unit (2) controls the power conversion unit (2) to enable the average current I _ L1 of the energy storage inductor L1 (15) to flow from the network V3 to the network V2, so that negative-going discharge of the second chargeable and dischargeable energy storage unit (4) in the second quadrant is completed, and at this time, the first chargeable and dischargeable energy storage unit (3) serves as an energy storage load and is charged by the power conversion unit (1).

Technical Field

The invention relates to the field of switch power supplies, in particular to a power conversion device and a control method of an isolated positive and negative output bidirectional transfer switch power supply.

Background

The conventional switching power supply can realize unidirectional conversion and transmission of power, and the output voltage is positive or negative. In some special application occasions, energy is required to be transmitted in two directions, the output voltage is variable in positive and negative, for example, in the field of bidirectional energization of lead-acid batteries, the conventional switching power supply is used, extra equipment is required to be added to realize the functions, and the switching power supply is high in cost and large in size.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to solve the technical problem of the prior art and provides a power conversion device and a control method of an isolated positive and negative output bidirectional transfer switching power supply.

In order to solve the technical problem, the invention discloses a power conversion device of a positive-negative bidirectional switching power supply, which comprises a power conversion unit, a control unit, a first chargeable and dischargeable energy storage unit and a second chargeable and dischargeable energy storage unit, wherein the first chargeable and dischargeable energy storage unit is connected with the control unit; the power conversion unit is respectively connected with the first chargeable and dischargeable energy storage unit and the second chargeable and dischargeable energy storage unit, and the control unit is respectively connected with and controls the power conversion unit, the first chargeable and dischargeable energy storage unit and the second chargeable and dischargeable energy storage unit.

In the invention, the power conversion unit (1) comprises a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a first switch tube Q1, a second switch tube Q2, a third switch tube Q3, a fourth switch tube Q4, a fifth switch tube Q5, a sixth switch tube Q6, an energy storage inductor L1 and a transformer T1;

one end of the energy storage inductor L1 is connected with a fourth capacitor C4, and the network is defined as V2;

the other end of the energy storage inductor L1 is connected with one end of a third switching tube Q3 and a PIN4 of a transformer T1, and a network is defined as V3;

the other end of the fourth capacitor C4 is commonly connected with a sixth switching tube Q6 and a fourth switching tube Q4, and the network is defined as GND 2; the other end of the sixth switching tube Q6 is connected with one end of the fifth switching tube Q5;

the other end of the fifth switching tube Q5 is connected with PIN5 of the transformer T1;

the other end of the fourth switching tube Q4 is connected with one end of a third switching tube Q3;

the other end of the third switching tube Q3 is connected with PIN3 of the transformer T1;

one end of the first capacitor C1 is commonly connected with the first switch tube Q1 and the second capacitor C2, and the network is defined as V1;

the other end of the first capacitor C1 is commonly connected with the second switch tube Q2 and the third capacitor C3, and the network is defined as GND 1; the other end of the first switch tube Q1 is connected with the other end of the second switch tube Q2;

the other end of the second capacitor C2 is connected with the other end of the third capacitor C3;

a control end of the first switching tube Q1, a control end of the second switching tube Q2, a control end of the third switching tube Q3, a control end of the fourth switching tube Q4, a control end of the fifth switching tube Q5 and a control end of the sixth switching tube Q6 are respectively connected to the control unit;

the control unit detects a voltage between V1 and GND1, a voltage between V2 and GND2, and a current I _ L1 of the energy storage inductor L1.

In the invention, the first chargeable and dischargeable energy storage unit is a chargeable and dischargeable energy storage device.

In the invention, the second chargeable and dischargeable energy storage unit is a chargeable and dischargeable energy storage device.

In the invention, when the voltage of the V2 is positive relative to the GND2 and the secondary chargeable and dischargeable energy storage unit needs to be charged in the forward direction, the control unit controls the power conversion unit to enable the average current I _ L1 of the energy storage inductor L1 to flow from the network V3 to the network V2, so that the secondary chargeable and dischargeable energy storage unit is charged in the forward direction in the first quadrant, and at the moment, the primary chargeable and dischargeable energy storage unit is used as a power supply to discharge to the power conversion unit;

when the voltage of the V2 is positive relative to the GND2 and the secondary rechargeable energy storage unit needs to be discharged in the forward direction, the control unit controls the power conversion unit to enable the average current I _ L1 of the energy storage inductor L1 to flow from the network V2 to the network V3, so that the secondary rechargeable energy storage unit is discharged in the forward direction in the fourth quadrant, and at the moment, the primary rechargeable energy storage unit serves as an energy storage load and is charged by the power conversion unit;

when the voltage of the V2 is negative relative to the GND2 and the secondary chargeable and dischargeable energy storage unit needs to be charged negatively, the control unit controls the power conversion unit to enable the average current I _ L1 of the energy storage inductor L1 to flow from the network V2 to the network V3, so that the secondary chargeable and dischargeable energy storage unit is charged negatively in the third quadrant, and at the moment, the primary chargeable and dischargeable energy storage unit serves as a power supply source to discharge to the power conversion unit;

when the voltage of V2 is negative relative to GND2 and negative-going discharging of the secondary chargeable and dischargeable energy storage unit is required, the control unit controls the power conversion unit to enable the average current I _ L1 of the energy storage inductor L1 to flow from the network V3 to the network V2, so that negative-going discharging of the secondary chargeable and dischargeable energy storage unit in the second quadrant is completed, and at the moment, the primary chargeable and dischargeable energy storage unit serves as an energy storage load and is charged by the power conversion unit.

Has the advantages that: 1. the conventional switching power supply can realize unidirectional conversion and transmission of power, and the output voltage can only be positive or negative; the device and the method provided by the patent realize the isolated bidirectional transmission of power, and the output voltage can output positive voltage and also can output negative voltage.

2. The device and the method can integrally realize the power conversion function of the isolated positive and negative output bidirectional transfer switching power supply, and do not need to connect a plurality of devices to realize the functions; the invention can provide higher power conversion efficiency and has the effect of energy saving.

Drawings

The foregoing and/or other advantages of the invention will become further apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.

Fig. 1 is a schematic diagram of a power conversion device and a control method of an isolated positive-negative output bidirectional transfer switching power supply according to the present invention.

Fig. 2 is a schematic diagram of the power conversion of the isolated positive and negative output bidirectional transfer switching power supply of the present invention.

Fig. 3 is a two-four quadrant current-voltage charge-discharge abstraction diagram of the chargeable and dischargeable energy storage unit of the present invention.

Detailed Description

As shown in fig. 1, the power conversion device comprises a power conversion unit, a control unit, a first chargeable and dischargeable energy storage unit and a second chargeable and dischargeable energy storage unit; the control unit is respectively connected with the power conversion unit, the first chargeable and dischargeable energy storage unit and the second chargeable and dischargeable energy storage unit.

The main control chip of the control unit adopts a TMS320F28335 model product of TI company, the control unit is also internally provided with a sampling conditioning circuit consisting of an operational amplifier L M258, a resistor, a capacitor and the like, the voltage of the battery and the current flowing through the battery are identified by sampling the terminal voltage of the storage battery and the current flowing through L1 and are supplied to the main control chip together, and the control unit is also internally provided with a driving circuit consisting of an isolation driving transformer, a diode, a capacitor, a resistor and the like.

As shown in fig. 2, the power conversion unit (1) includes a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a first switch tube Q1, a second switch tube Q2, a third switch tube Q3, a fourth switch tube Q4, a fifth switch tube Q5, a sixth switch tube Q6, an energy storage inductor L1, and a transformer T1;

one end of the energy storage inductor L1 is connected with a fourth capacitor C4, and the network is defined as V2;

the other end of the energy storage inductor L1 is connected with one end of a third switching tube Q3 and a PIN4 of a transformer T1, and a network is defined as V3;

the other end of the fourth capacitor C4 is commonly connected with a sixth switching tube Q6 and a fourth switching tube Q4, and the network is defined as GND 2; the other end of the sixth switching tube Q6 is connected with one end of the fifth switching tube Q5;

the other end of the fifth switching tube Q5 is connected with PIN5 of the transformer T1;

the other end of the fourth switching tube Q4 is connected with one end of a third switching tube Q3;

the other end of the third switching tube Q3 is connected with PIN3 of the transformer T1;

one end of the first capacitor C1 is commonly connected with the first switch tube Q1 and the second capacitor C2, and the network is defined as V1;

the other end of the first capacitor C1 is commonly connected with the second switch tube Q2 and the third capacitor C3, and the network is defined as GND 1; the other end of the first switch tube Q1 is connected with the other end of the second switch tube Q2;

the other end of the second capacitor C2 is connected with the other end of the third capacitor C3;

a control terminal of the first switching tube Q1, a control terminal of the second switching tube Q2, a control terminal of the third switching tube Q3, a control terminal of the fourth switching tube Q4, a control terminal of the fifth switching tube Q5 and a control terminal of the sixth switching tube Q6 are respectively connected to the control unit 2.

The control unit 2 detects a voltage between V1 and GND1, a voltage between V2 and GND2 and a current I _ L1 of an energy storage inductor L1, the control unit detects a voltage between V1 and GND1, the control unit detects a voltage between V2 and GND2, and the control unit detects a current I _ L1 of L1, the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4, the fifth switch tube Q5 and the sixth switch tube Q6 are all power MOSFETs, and voltage drop generated when the power MOSFETs are fully conducted is enabled to be as small as possible.

The first chargeable and dischargeable energy storage unit is a chargeable and dischargeable energy storage device, such as a capacitor, a battery, etc., and fig. 1 takes the battery as an example; the first chargeable and dischargeable energy storage unit can be externally connected with a power supply and a discharge load or connected with both the power supply and the discharge load; the first chargeable and dischargeable energy storage unit is connected with one end of the power conversion unit; the network V1 is connected to the anode of the first chargeable and dischargeable energy storage unit, and the network GND1 is connected to the cathode of the first chargeable and dischargeable energy storage unit.

The second chargeable and dischargeable energy storage unit is a chargeable and dischargeable energy storage device, such as a capacitor, a battery, etc., and fig. 1 takes the battery as an example; the second chargeable and dischargeable energy storage unit can be externally connected with a power supply and a discharge load or connected with both the power supply and the discharge load; the second chargeable and dischargeable energy storage unit is connected with one end of the power conversion unit; the network V2 is connected with the anode of the second chargeable and dischargeable energy storage unit, and the network GND2 is connected with the cathode of the second chargeable and dischargeable energy storage unit.

In the present invention, a power conversion control method for an isolated positive-negative output bidirectional transfer switching power supply is also provided, which specifically describes the case of implementing the method, as shown in fig. 3:

in case 1, when the voltage of the V2 is positive relative to GND2 and two chargeable and dischargeable energy storage units need to be charged in the forward direction, the control unit controls six pipes Q1-Q6 of the power conversion unit to be turned on and off, specifically, Q4& Q6 are turned on and off simultaneously for one group, Q1& Q5 are defined as an A group, Q2& Q3 are defined as a B group, and two groups of A, B are turned on alternately, step 1, A is conducted in a pilot mode, step 2, A is turned off, step 3, B is conducted, step 4, B is turned on, and step 1-4 are repeated after toff time, and the average current I _ L1 of the energy storage inductor L1 flows from the network V3 to the network V2, so that the first quadrant charges the two chargeable and dischargeable energy storage units in the forward direction.

The voltage of C1 is defined as v 1; the voltage of C2 is defined as v 2; the original secondary side turn ratio of T1 is n:

they conform to the relationship: v2 ═ 0.5 × v1 × ton/(ton + toff)/n.

Case 2, when the voltage of V2 is positive relative to GND2 and positive discharging of a second chargeable and dischargeable energy storage unit is needed, the control unit controls six pipes Q1-Q6 of the power conversion unit to be turned on and off, specifically Q4& Q6, step 1, Q3& Q5 turns on ton1, step 2, Q3 turns off & Q1 turns on time period length toff, toff represents the time that Q3 turns off & Q1 turns on, step 3, Q3& Q5 turns on ton1, step 4, Q5 turns off & Q2 turns on toff, step 1-4 is repeated, the average current I _ L1 of an energy storage inductor L1 flows from a network V2 to a network V3, positive discharging of the second chargeable and dischargeable energy storage unit in a fourth quadrant is completed, and the first chargeable and dischargeable energy storage unit serves as an energy storage load and is charged by the power conversion unit;

the voltage of C1 is defined as v 1; the voltage of C2 is defined as v 2; the original secondary side turn ratio of T1 is n:

they conform to the relationship: v1 ═ 2 × v2 × n (ton + toff)/toff.

Case 3, when the voltage of the first chargeable and dischargeable energy storage unit is negative relative to GND2 and two chargeable and dischargeable energy storage units need to be negatively charged, the control unit controls six pipes Q1-Q6 of the power conversion unit to be turned on and off, specifically, six pipes Q3& Q8934 are turned on and off simultaneously, a group A is defined as a group Q1& Q4, a group A is defined as a group Q2& Q6, a group B is defined as a group Q2& Q6, two groups A, B are turned on alternately, step 1: A pilot on ton, step 2: A is turned off, step 3: B on ton is carried out after toff time, wherein ton represents a time period of B conduction, step 4: B is turned off, and after toff time, steps 1-4 are repeated, the average current I _ L of the energy storage inductor L flows from the network V2 to the network V3, the negative charging of the second chargeable and dischargeable energy storage unit in the third quadrant is completed, and the negative charging of the second chargeable and dischargeable energy storage unit is used as a power supply, the voltage V1 is defined as a sub-2, the voltage ratio T35v 737:

they conform to the relationship: v2 ═ 0.5 × v1 × ton/(ton + toff)/n.

In case 4, when the voltage of the V2 is negative relative to GND2 and negative discharging of the two chargeable and dischargeable energy storage units is needed, the control unit controls six pipes Q1-Q6 of the power conversion unit to be turned on and off, specifically, Q3& Q5 to be turned on, Q4& Q6 to be turned on ton1, Q6 is turned off & Q1 to be turned on toff, Q4& Q6 is turned on ton1, Q4 is turned off & Q2 to be turned on toff, the steps 1-4 are repeated, the average current I _ L1 of the energy storage inductor L flows from the network V3 to the network V2, negative discharging of the two chargeable and dischargeable energy storage units in the second quadrant is completed, the one chargeable and dischargeable energy storage unit serves as an energy storage load and is charged by the power conversion unit, energy can be bidirectionally converted between the one chargeable and dischargeable energy storage unit and the two chargeable and dischargeable energy storage units, and the C4 can be positive relative to GND 2.

Under the 4 conditions, the power conversion of the isolated positive-negative output bidirectional transfer switching power supply between the first chargeable and dischargeable energy storage unit and the second chargeable and dischargeable energy storage unit can be realized.

Experiments show that the energy isolation between the 48V battery and the 2V battery is mutually converted, the conversion efficiency from 48V to 2V is more than 90%, and the conversion efficiency from 2V to 48V is more than 80%, so that the power conversion device and the method for the isolated positive and negative output bidirectional transfer switching power supply are high-efficiency, low-cost and small-size. In this example, at least 2 power MOSFETs can be saved relative to a device in which a first-stage forward bidirectional switching power supply is added with a first-stage full-bridge inverter; compared with a coincidence device formed by a positive bidirectional switch power supply, a negative switch power supply and a control circuit, the cost and the volume can be saved by more than half, and the economic value of the invention is obvious. The following is according to the efficiency test data of the integrated device made by this embodiment, and it can be seen that the conversion efficiency is high, which is beneficial to energy saving and environmental protection.

The present invention provides a power conversion device and a control method for a positive-negative bidirectional switch power supply, and a plurality of methods and ways for implementing the technical scheme, the above description is only a preferred embodiment of the present invention, it should be noted that, for those skilled in the art, a plurality of improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention. All the components not specified in the present embodiment can be realized by the prior art.