Energy storage converter push-pull circuit, energy storage converter and push-pull control method thereof

Abstract

The invention provides an energy storage converter push-pull circuit, an energy storage converter and a push-pull control method thereof. The push-pull circuit of the energy storage converter comprises two metal oxide semiconductor tubes, a transformer, a controller and a source-drain voltage detection assembly, in response to access of the energy storage battery, the controller gradually increases the duty ratio of a pulse width signal for controlling opening and closing of the metal oxide semiconductor tube so as to control source-drain voltage on a drain electrode of the metal oxide semiconductor tube, the source-drain voltage detection assembly compares the source-drain voltage with threshold voltage, and if the source-drain voltage is larger than the threshold voltage, the source-drain voltage detection assembly detects that the source-drain voltage is larger than the threshold voltage. The trigger controller changes the duty ratio of the pulse width signal into a second value, the second value is smaller than or equal to the first value, and the first value is the value of the duty ratio of the pulse width signal when the source-drain voltage is larger than the threshold voltage. The voltage endurance capability of the metal oxide semiconductor is fully utilized, and the starting time is shortened.

Description

Technical Field

[0001] This invention relates to the field of energy storage system technology, and more specifically, to a push-pull circuit for an energy storage converter, an energy storage converter, and a push-pull control method thereof. Background Technology

[0002] In energy storage systems, when the energy storage battery needs to power a load, the DC voltage output by the battery is often too low and needs to be boosted. However, boosting DC voltage is difficult, so a push-pull circuit is used to convert the DC voltage to AC voltage, which is then boosted by a transformer. The push-pull circuit consists of two metal-oxide-semiconductor (MOSFETs) that operate alternately. When one MOSFET is on, the other is off. When the on MOSFET is off, the transformer primary winding releases the magnetic energy injected when the MOSFET was on, generating a reverse induced voltage. This voltage, combined with the voltage generated when the off MOSFET becomes on, results in a significant source-drain voltage between the source and drain of the MOSFET when the energy storage battery is newly connected. This voltage can be up to four times the output voltage of the energy storage battery.

[0003] Currently, this problem can be alleviated by gradually increasing the duty cycle of the pulse width signal controlling the switching of the MOSFET. Instead of immediately reaching the ideal duty cycle, the sampling rate is gradually increased. The amplification factor of the source-drain voltage relative to the battery's output voltage is related to the pulse width signal duty cycle. When the battery is newly connected, a relatively large source-drain voltage is generated due to the influence of reverse induced voltage. This voltage can be reduced by keeping the pulse width signal duty cycle very small. For example, if the ideal duty cycle is 50%, it can be gradually increased from 5%, 10%, 15%, etc., to 50%. However, this gradual increase in the pulse width signal duty cycle is wasteful of the MOSFET's performance when the maximum tolerable source-drain voltage is large, resulting in a long startup time, especially when the battery's output voltage is relatively small. Furthermore, different MOSFETs have different process parameters, leading to different maximum tolerable source-drain voltages. A gradual increase in duty cycle, as designed for a certain metal-oxide-semiconductor (MOSFET), may cause another MOSFET to exceed its maximum tolerable source-drain voltage and be damaged. Summary of the Invention

[0004] The present invention aims to solve one of the technical problems existing in the prior art or related technologies.

[0005] Therefore, the first aspect of the present invention proposes a push-pull circuit for an energy storage converter.

[0006] A second aspect of the present invention provides an energy storage converter.

[0007] A third aspect of the present invention proposes a push-pull control method for an energy storage converter.

[0008] In view of this, according to a first aspect of the present invention, a push-pull circuit for an energy storage converter is proposed, comprising: two metal-oxide-semiconductor (MOSFETs) with their sources grounded, a transformer, a controller, and a source-drain voltage detection component. The drains of the two MOSFETs are respectively coupled to a first end and a second end of the primary winding of the transformer. The center tap of the primary winding of the transformer is used to couple an energy storage battery to ground. The controller is respectively coupled to the gates of the two MOSFETs. The drains of the two MOSFETs are coupled to the input terminal of the source-drain voltage detection component, and the output terminal of the source-drain voltage detection component is coupled to the controller. In response to the connection of the energy storage battery, the controller gradually increases the duty cycle of the pulse width signal controlling the opening and closing of the MOSFETs, thereby controlling the source-drain voltage on the drain of the MOSFETs. The source-drain voltage detection component compares the source-drain voltage with a threshold voltage. If the source-drain voltage is greater than the threshold voltage, the controller is triggered to change the duty cycle of the pulse width signal to a second value, wherein the second value is less than or equal to the first value, and the first value is the value of the pulse width signal duty cycle when the source-drain voltage is greater than the threshold voltage.

[0009] The push-pull circuit for an energy storage converter provided by this invention mainly includes: two metal-oxide-semiconductor (MOSFETs), a transformer, a controller, and a source-drain voltage detection component. The sources of the two MOSFETs are grounded, and their drains are coupled to the first and second terminals of the primary winding of the transformer, respectively. The center tap of the primary winding of the transformer is coupled to a storage battery, meaning the positive terminal of the storage battery is connected to the center tap of the primary winding of the transformer, and the negative terminal of the storage battery is connected to ground. The signal output port of the controller is connected to the gates of the two MOSFETs, and the controller can output pulse signals through the signal output port to control the conduction and disconnection of the two MOSFETs. The drains of the two MOSFETs are coupled to the input terminal of the source-drain voltage detection component, and the output terminal of the source-drain voltage detection component is coupled to the controller. The source-drain voltage detection component can detect the source-drain voltage of the two MOSFETs, compare the detected source-drain voltage with a threshold voltage, and output the comparison result to the controller, so that the controller controls the two MOSFETs according to the comparison result.

[0010] After the energy storage battery is connected, the controller gradually increases the duty cycle of the pulse width signal controlling the switching of the metal-oxide-semiconductor (MOSFET) to achieve soft start. Simultaneously, it controls the source-drain voltage at the drain of the MOSFET. The source-drain voltage detection component compares the detected source-drain voltage with a threshold voltage. When the source-drain voltage at the drain of either MOSFET exceeds the threshold voltage, the controller is triggered to change the pulse width signal duty cycle to a second value, where the second value is less than or equal to the first value. The first value is the pulse width signal duty cycle value when the source-drain voltage is greater than the threshold voltage. In other words, when the source-drain voltage is greater than the threshold voltage, the controller reverts the pulse width signal duty cycle to its previous value. Then, when the source-drain voltage is less than the threshold voltage, the pulse width signal duty cycle is gradually increased. This fully utilizes the voltage withstand capability of the MOSFET, reduces startup time, and ensures the safety of the MOSFET. Meanwhile, when the maximum source-drain voltage tolerance of various metal-oxide-semiconductor transistors differs due to process variations, this invention can flexibly adapt to metal-oxide-semiconductor transistors with different processes by backing down based on the actual detected source-drain voltage and threshold voltage relationship.

[0011] In some technical solutions, optionally, the controller periodically changes the duty cycle of the pulse width signal, wherein the controller is specifically used to: set the second value of the second cycle after the first cycle to be equal to the first value, the first cycle being the cycle in which the source-drain voltage is detected to be greater than the threshold voltage; and set the second value of the third cycle after the second cycle to be less than the first value.

[0012] In some technical solutions, optionally, the second value is the product of the first value and a predetermined ratio, where the predetermined ratio is a positive number less than 1.

[0013] In some technical solutions, optionally, after the controller changes the duty cycle of the pulse width signal to the second value, it continues to gradually increase the duty cycle of the pulse width signal until the duty cycle of the pulse width signal reaches the target value.

[0014] In some technical solutions, optionally, the two metal-oxide-semiconductor (MOSFETs) include a first MOSFET and a second MOSFET; the source-drain voltage detection component includes a first comparator and a second comparator; the threshold voltage includes a first threshold voltage and a second threshold voltage; the first input terminal of the first comparator is coupled to the drain of the first MOSFET, the second input terminal of the first comparator is coupled to the first threshold voltage, and the output terminal of the first comparator is coupled to the input pin of the controller; the first input terminal of the second comparator is coupled to the drain of the second MOSFET, the second input terminal of the second comparator is coupled to the second threshold voltage, and the output terminal of the second comparator is coupled to the input pin of the controller.

[0015] In some technical solutions, optionally, the source-drain voltage detection component includes a first voltage divider resistor, a second voltage divider resistor, a third voltage divider resistor, and a fourth voltage divider resistor; the drain of the first metal-oxide-semiconductor transistor is coupled to the first input terminal of the first comparator through the first voltage divider resistor, and the first input terminal of the first comparator is grounded through the second voltage divider resistor; the drain of the second metal-oxide-semiconductor transistor is coupled to the first input terminal of the second comparator through the third voltage divider resistor, and the first input terminal of the second comparator is grounded through the fourth voltage divider resistor.

[0016] In some technical solutions, optionally, the first threshold voltage is the product of the first maximum operating source-drain voltage of the first metal-oxide-semiconductor transistor and the first voltage division ratio, and the first voltage division ratio is the ratio of the second voltage dividing resistor to the sum of the resistances of the first voltage dividing resistor and the second voltage dividing resistor; the second threshold voltage is the product of the second maximum operating source-drain voltage of the second metal-oxide-semiconductor transistor and the second voltage division ratio, and the second voltage division ratio is the ratio of the fourth voltage dividing resistor to the sum of the resistances of the third voltage dividing resistor and the fourth voltage dividing resistor.

[0017] In some technical solutions, the energy storage converter push-pull circuit may optionally include a driver chip. The output pin of the controller is coupled to the driver chip to transmit a pulse width signal with a pulse width signal duty cycle to the driver chip, so as to control the driver chip to turn the two metal oxide semiconductor transistors on and off according to the pulse width signal duty cycle.

[0018] According to a second aspect of the present invention, an energy storage converter is provided, wherein the energy storage converter includes: a push-pull circuit of the energy storage converter as described in any of the above technical solutions; a rectifier coupled to the secondary winding of a transformer for converting the AC boost voltage obtained by the push-pull circuit of the energy storage converter for the DC output voltage of the energy storage battery into a DC boost voltage; and an inverter circuit coupled to the rectifier for converting the DC boost voltage output by the rectifier into an AC output voltage for supplying power to the load.

[0019] The energy storage converter provided by this invention mainly includes: an energy storage converter push-pull circuit, a rectifier, and an inverter circuit. The energy storage converter push-pull circuit is the same as the one described in any of the above technical solutions. The rectifier is coupled to the secondary winding of the transformer, and the rectifier can convert the DC output voltage of the energy storage battery from the energy storage converter push-pull circuit into an AC boost voltage. The inverter circuit is coupled to the rectifier, and the inverter circuit can convert the DC boost voltage output by the rectifier into an AC output voltage, which then supplies power to the load.

[0020] According to a third aspect of the present invention, a push-pull control method for an energy storage converter is proposed for an energy storage converter push-pull circuit. The energy storage converter push-pull circuit includes two metal-oxide-semiconductor (MOS) transistors with their sources grounded, a transformer, and a source-drain voltage detection component. The drains of the two MOS transistors are respectively coupled to a first end and a second end of the primary winding of the transformer. The center tap of the primary winding of the transformer is used to couple an energy storage battery to ground. The drains of the two MOS transistors are coupled to the source-drain voltage detection component. The energy storage converter push-pull control method includes: in response to the connection of the energy storage battery, gradually increasing the duty cycle of the pulse width signal controlling the on / off state of the MOS transistors, thereby controlling the source-drain voltage at the drain of the MOS transistors; if the source-drain voltage is greater than a threshold voltage, changing the pulse width signal duty cycle to a second value, wherein the second value is less than or equal to a first value, and the first value is the value of the pulse width signal duty cycle when the source-drain voltage is greater than the threshold voltage.

[0021] The push-pull control method for energy storage converters provided by this invention is mainly used in push-pull circuits of energy storage converters. The push-pull circuit includes two metal-oxide-semiconductor (MOS) transistors, a transformer, a controller, and a source-drain voltage detection component. The sources of the two MOS transistors are grounded, and their drains are coupled to the first and second terminals of the primary winding of the transformer, respectively. The center tap of the primary winding of the transformer is coupled to a storage battery, meaning the positive terminal of the storage battery is connected to the center tap of the primary winding of the transformer, and the negative terminal of the storage battery is connected to ground. The signal output port of the controller is connected to the gates of the two MOS transistors, and the controller can output pulse signals through the signal output port to control the conduction and disconnection of the two MOS transistors. The drains of the two metal-oxide-semiconductor transistors are coupled to the input of the source-drain voltage detection component, and the output of the source-drain voltage detection component is coupled to the controller. The source-drain voltage detection component can detect the source-drain voltage of the two metal-oxide-semiconductor transistors, compare the detected source-drain voltage with the threshold voltage, and output the comparison result to the controller so that the controller controls the two metal-oxide-semiconductor transistors according to the comparison result.

[0022] The push-pull control method for energy storage converters includes the following steps: After the energy storage battery is connected, the duty cycle of the pulse width signal controlling the switching of the metal-oxide-semiconductor (MOSFET) is gradually increased to achieve soft start, while simultaneously controlling the source-drain voltage at the drain of the MOSFET. Subsequently, the source-drain voltage detection component compares the detected source-drain voltage with a threshold voltage. When the source-drain voltage at the drain of either MOSFET exceeds the threshold voltage, the duty cycle of the pulse width signal is changed to a second value, where the second value is less than or equal to the first value. The first value is the pulse width signal duty cycle value when the source-drain voltage is greater than the threshold voltage. In other words, when the source-drain voltage is greater than the threshold voltage, the pulse width signal duty cycle is reverted to its previous value. Then, when the source-drain voltage is less than the threshold voltage, the pulse width signal duty cycle is gradually increased. This fully utilizes the voltage withstand capability of the MOSFET, reduces start-up time, and ensures the safety of the MOSFET. Meanwhile, when the maximum source-drain voltage tolerance of various metal-oxide-semiconductor transistors differs due to process variations, this invention can flexibly adapt to metal-oxide-semiconductor transistors with different processes by backing down based on the actual detected source-drain voltage and threshold voltage relationship.

[0023] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0025] Figure 1 A schematic diagram of the structure of an energy storage converter according to an embodiment of the present invention is shown;

[0026] Figure 2 A schematic flowchart of a push-pull control method for an energy storage converter according to an embodiment of the present invention is shown.

[0027] in, Figure 1 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0028] 10 Energy storage converter, 100 Energy storage converter push-pull circuit, 102 Metal-oxide-semiconductor (MOSFET), 104 Transformer, 106 Controller, 108 Source-drain voltage detection component, 110 Primary winding, 112 Energy storage battery, Q1 First MOSFET, Q2 Second MOSFET, U1 First comparator, U2 Second comparator, R1 First voltage divider resistor, R2 Second voltage divider resistor, R3 Third voltage divider resistor, R4 Fourth voltage divider resistor, 114 Driver chip, 116 Rectifier, 118 Inverter circuit, V1 Source-drain voltage, Vref1 First threshold voltage, Vref2 Second threshold voltage, 120 Secondary winding, R5 Fifth resistor, R6 Sixth resistor, R7 Seventh resistor, VCC Power supply. Detailed Implementation

[0029] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0030] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0031] like Figure 1 As shown, this invention proposes a push-pull circuit 100 for an energy storage converter, comprising: two metal-oxide-semiconductor (MOS) transistors 102 with their sources grounded, a transformer 104, a controller 106, and a source-drain voltage detection component 108. The drains of the two MOS transistors 102 are respectively coupled to the first and second ends of the primary winding 110 of the transformer 104. The center tap of the primary winding 110 of the transformer 104 is used to couple an energy storage battery 112 to ground. The controller 106 is respectively coupled to the gates of the two MOS transistors 102, and the drains of the two MOS transistors 102 are coupled to the source-drain voltage detection component 108. At the input terminal, the output terminal of the source-drain voltage detection component 108 is coupled to the controller 106; wherein, in response to the connection of the energy storage battery 112, the controller 106 gradually increases the duty cycle of the pulse width signal controlling the opening and closing of the metal oxide semiconductor transistor 102, thereby controlling the source-drain voltage V1 on the drain of the metal oxide semiconductor transistor 102. The source-drain voltage detection component 108 compares the source-drain voltage V1 with a threshold voltage. If the source-drain voltage V1 is greater than the threshold voltage, the controller 106 is triggered to change the duty cycle of the pulse width signal to a second value, wherein the second value is less than or equal to the first value, and the first value is the value of the duty cycle of the pulse width signal when the source-drain voltage V1 is greater than the threshold voltage.

[0032] The energy storage converter push-pull circuit 100 provided by this invention mainly includes: two metal-oxide-semiconductor (MOS) transistors 102, a transformer 104, a controller 106, and a source-drain voltage detection component 108. The sources of the two MOS transistors 102 are grounded, and their drains are coupled to the first and second ends of the primary winding 110 of the transformer 104, respectively. The center tap of the primary winding 110 of the transformer 104 is coupled to a storage battery 112, meaning the positive terminal of the storage battery 112 is connected to the center tap of the primary winding 110 of the transformer 104, and the negative terminal of the storage battery 112 is connected to ground. The signal output port of the controller 106 is connected to the gates of the two MOS transistors 102, and the controller 106 can output pulse signals through the signal output port to control the on and off states of the two MOS transistors 102. The drains of the two metal-oxide-semiconductor transistors 102 are coupled to the input of the source-drain voltage detection component 108, and the output of the source-drain voltage detection component 108 is coupled to the controller 106. The source-drain voltage detection component 108 can detect the source-drain voltage V1 of the two metal-oxide-semiconductor transistors 102, compare the detected source-drain voltage V1 with the threshold voltage, and output the comparison result to the controller 106 so that the controller 106 controls the two metal-oxide-semiconductor transistors 102 according to the comparison result.

[0033] After the energy storage battery 112 is connected, the controller 106 gradually increases the duty cycle of the pulse width signal controlling the opening and closing of the metal oxide semiconductor transistor 102 to achieve soft start. At the same time, it can also control the source-drain voltage V1 on the drain of the metal oxide semiconductor transistor 102. Simultaneously, the source-drain voltage detection component 108 compares the detected source-drain voltage V1 with the threshold voltage. When the source-drain voltage V1 at the drain of either of the two metal-oxide-semiconductor transistors 102 is greater than the threshold voltage, the controller 106 is triggered to change the pulse width signal duty cycle to a second value, wherein the second value is less than or equal to the first value. The first value is the pulse width signal duty cycle value when the source-drain voltage V1 is greater than the threshold voltage. That is, when the source-drain voltage V1 is greater than the threshold voltage, the controller 106 reverts the pulse width signal duty cycle back to the previous pulse width signal duty cycle. Subsequently, when the source-drain voltage V1 is less than the threshold voltage, the pulse width signal duty cycle is gradually increased. This fully utilizes the withstand voltage capability of the metal-oxide-semiconductor transistor 102, reduces the startup time, and ensures the safety of the metal-oxide-semiconductor transistor 102. Meanwhile, in cases where the maximum source-drain voltage V1 tolerance of each metal-oxide-semiconductor transistor 102 differs due to process differences, the present invention can flexibly adapt to metal-oxide-semiconductor transistors 102 with various processes by backing down based on the actual detected relationship between the source-drain voltage V1 and the threshold voltage.

[0034] In the initial stage of connecting the energy storage battery 112, this invention, while gradually increasing the duty cycle of the pulse width signal controlling the on / off state of the metal-oxide-semiconductor (MOS) transistor 102 according to a predetermined strategy, also measures the source-drain voltage V1 of the MOS transistor 102 in real time. If the source-drain voltage V1 is greater than a threshold voltage, the controller 106 is triggered to reduce the pulse width signal duty cycle, and then the pulse width signal duty cycle is gradually increased again according to the predetermined strategy. Compared with existing schemes that simply increase the pulse width signal duty cycle according to a predetermined strategy without considering the real-time measured source-drain voltage V1, this invention can quickly increase the pulse width signal duty cycle in large steps when the maximum withstand voltage V1 of the MOS transistor 102 is large and the output voltage of the energy storage battery 112 is small. This raises the source-drain voltage V1 to near the maximum withstand voltage V1, fully utilizing the voltage withstand capability of the MOS transistor and reducing startup time. When the maximum source-drain voltage V1 that the metal-oxide-semiconductor (MOSFET) 102 can withstand is relatively small, while the output voltage of the energy storage battery 112 is relatively large, according to the scheme of this embodiment, if the source-drain voltage V1 is greater than the threshold voltage, the controller 106 is triggered to reduce the pulse width signal duty cycle, so that the MOSFET will not be damaged. On this basis, the pulse width signal duty cycle is gradually increased according to a predetermined strategy, thereby maximizing the utilization of the MOSFET's voltage withstand capability without damaging the MOSFET. At the same time, for cases where different MOSFETs 102 have different process parameters, resulting in different maximum source-drain voltages V1, since the pulse width signal duty cycle control strategy changes with the comparison result of the real-time detected source-drain voltage V1 and the threshold voltage, if the source-drain voltage V1 is greater than the threshold voltage, the pulse width signal duty cycle is triggered to fall back. Therefore, it can adapt to MOSFETs 102 with different process parameters, improving the tolerance of MOSFET process differences.

[0035] In some embodiments, optionally, the controller 106 periodically changes the duty cycle of the pulse width signal, wherein the controller 106 is specifically configured to: set a second value of a second period after a first period to be equal to a first value, the first period being the period in which the source-drain voltage V1 is detected to be greater than a threshold voltage; and set a second value of a third period after a second period to be less than the first value.

[0036] In this embodiment, the controller 106 can periodically change the pulse width signal duty cycle. That is, the controller 106 can periodically output a pulse width signal to control the switching on and off of the two metal-oxide-semiconductor (MOSFETs) 102, and the pulse width signals of the MOSFETs 102 are complementary. The pulse width signal output in each cycle is different, and the pulse width signal duty cycle gradually increases with each subsequent cycle. When the source-drain voltage V1 is detected to be greater than the threshold voltage in the first cycle, the pulse width signal duty cycle at this time is taken as the first value and recorded. Subsequently, the pulse width signal duty cycle in the second cycle after the first cycle is set to a second value equal to the first value, and finally, the pulse width signal duty cycle in the third cycle after the second cycle is set to a second value less than the first value. It is understood that the two MOSFETs 102 are switched on and off alternately; one MOSFET 102 is on in one cycle, and the other MOSFET 102 is on in the next cycle. Therefore, detecting a source-drain voltage V1 greater than the threshold voltage does not necessarily indicate the situation in the next cycle. If the second value in the next cycle is immediately changed to be less than the first value, the two metal-oxide-semiconductor transistors 102 will operate inconsistently, which can easily cause magnetization. Therefore, in the next cycle, the second value is first changed to be equal to the first value, and then in the cycle after that, the second value is changed to be less than the first value. This avoids the problem of magnetization of transformer 104 caused by the different switching cycles of transformer 104.

[0037] In some embodiments, the second value may optionally be the product of the first value and a predetermined ratio, where the predetermined ratio is a positive number less than 1.

[0038] In this embodiment, the second value is the product of the first value and a predetermined ratio, where the predetermined ratio is a positive number less than 1. The predetermined ratio can be 50%. For example, if the source-drain voltage V1 is greater than the threshold voltage when the first value is 30%, then the second value is set to 30% × 50% = 15%. This invention defines the duty cycle adjustment method, thereby ensuring the normal operation of the system.

[0039] In some embodiments, optionally, after the controller 106 changes the pulse width signal duty cycle to the second value, it continues to gradually increase the pulse width signal duty cycle until the pulse width signal duty cycle reaches the target value.

[0040] In this embodiment, after the controller 106 changes the pulse width signal duty cycle to the second value, if the source-drain voltage V1 is less than the threshold voltage, the controller 106 continues to gradually increase the control pulse width signal duty cycle until it reaches the target value. For example, when the pulse width signal duty cycle reaches 30%, the source-drain voltage V1 is 30V, but the threshold voltage is 25V, indicating that the source-drain voltage V1 is greater than the threshold voltage. Therefore, the pulse width signal duty cycle is reduced to 15%, and then gradually increased in predetermined steps. After the pulse width signal duty cycle reaches the target value, the source-drain voltage stabilizes, preventing damage to the metal-oxide-semiconductor transistor 102. In this invention, after changing the pulse width signal duty cycle to the second value, the controller 106 continues to gradually increase the control pulse width signal duty cycle until it reaches the target value, thereby completing the soft start of the system.

[0041] In some embodiments, optionally, such as Figure 1 As shown, the two metal-oxide-semiconductor transistors 102 include a first metal-oxide-semiconductor transistor Q1 and a second metal-oxide-semiconductor transistor Q2; the source-drain voltage detection component 108 includes a first comparator U1 and a second comparator U2; the threshold voltage includes a first threshold voltage Vref1 and a second threshold voltage Vref2; the first input terminal of the first comparator U1 is coupled to the drain of the first metal-oxide-semiconductor transistor Q1, the second input terminal of the first comparator U1 is coupled to the first threshold voltage Vref1, and the output terminal of the first comparator U1 is coupled to the input pin of the controller 106; the first input terminal of the second comparator U2 is coupled to the drain of the second metal-oxide-semiconductor transistor Q2, the second input terminal of the second comparator U2 is coupled to the second threshold voltage Vref2, and the output terminal of the second comparator U2 is coupled to the input pin of the controller 106.

[0042] In this embodiment, the two metal-oxide-semiconductor (MOSFETs) 102 are a first MOSFET Q1 and a second MOSFET Q2, respectively. The source-drain voltage detection component 108 includes a first comparator U1 and a second comparator U2. The threshold voltages include a first threshold voltage Vref1 and a second threshold voltage Vref2. The first input terminal of the first comparator U1 is connected to the drain of the first MOSFET Q1, the second input terminal of the first comparator U1 is coupled to the first threshold voltage Vref1, and the output terminal of the first comparator U1 is connected to the input pin of the controller 106. The first comparator U1 compares the source-drain voltage V1 of the first MOSFET Q1 with the first threshold voltage Vref1 and outputs high- or low-level signals to the input pin of the controller 106 based on the comparison result. For example, when the source-drain voltage V1 of the first MOSFET Q1 is greater than the first threshold voltage Vref1, the first comparator U1 outputs a high-level signal; when the source-drain voltage V1 of the first MOSFET Q1 is less than the first threshold voltage Vref1, the first comparator U1 outputs a low-level signal. The first input terminal of the second comparator U2 is connected to the drain of the second metal-oxide-semiconductor (MOSFET) Q2, and the second input terminal of the second comparator U2 is coupled to the second threshold voltage Vref2. The output terminal of the second comparator U2 is connected to the input pin of the controller 106. The second comparator U2 compares the source-drain voltage V1 of the second MOSFET Q2 with the second threshold voltage Vref2 and outputs a high-level signal to the input pin of the controller 106 according to the comparison result. For example, when the source-drain voltage V1 of the second MOSFET Q2 is greater than the second threshold voltage Vref2, the second comparator U2 outputs a high-level signal; when the source-drain voltage V1 of the second MOSFET Q2 is less than the second threshold voltage Vref2, the second comparator U2 outputs a low-level signal. Optionally, the input pin of the controller 106 connected to the first comparator U1 and the input pin of the controller 106 connected to the second comparator U2 are the same input pin. This is achieved by setting the two MOSFETs 102 as the first MOSFET Q1 and the second MOSFET Q2, respectively. The source-drain voltage detection component 108 includes a first comparator U1 and a second comparator U2. The threshold voltages include a first threshold voltage Vref1 and a second threshold voltage Vref2. This enables the comparison of the source-drain voltage V1 of the two metal-oxide-semiconductor transistors 102 with the threshold voltages, and the input of the result to the controller 106.

[0043] For example, such as Figure 1As shown, the energy storage converter push-pull circuit 100 further includes a fifth resistor R5, wherein the first end of the fifth resistor R5 is connected to the power supply VCC, the second end of the fifth resistor R5 is connected to the output of the first comparator U1 and the output of the second comparator U2 respectively, and the second end of the fifth resistor R5 is also connected to the input pin of the controller 106. By setting the fifth resistor R5, when either the output of the first comparator U1 or the output of the second comparator U2 outputs a low-level signal, the input pin of the controller 106 can receive a low-level signal.

[0044] In some embodiments, optionally, such as Figure 1 As shown, the source-drain voltage detection component 108 includes a first voltage divider resistor R1, a second voltage divider resistor R2, a third voltage divider resistor R3, and a fourth voltage divider resistor R4; the drain of the first metal-oxide-semiconductor transistor Q1 is coupled to the first input terminal of the first comparator U1 through the first voltage divider resistor R1, and the first input terminal of the first comparator U1 is grounded through the second voltage divider resistor R2; the drain of the second metal-oxide-semiconductor transistor Q2 is coupled to the first input terminal of the second comparator U2 through the third voltage divider resistor R3, and the first input terminal of the second comparator U2 is grounded through the fourth voltage divider resistor R4.

[0045] In this embodiment, the source-drain voltage detection component 108 includes a first voltage divider resistor R1, a second voltage divider resistor R2, a third voltage divider resistor R3, and a fourth voltage divider resistor R4. The drain of the first metal-oxide-semiconductor transistor Q1 is coupled to the first input terminal of the first comparator U1 through the first voltage divider resistor R1. The first input terminal of the first comparator U1 is grounded through the second voltage divider resistor R2. The first and second voltage divider resistors R1 and R2 divide the source-drain voltage V1 of the first metal-oxide-semiconductor transistor Q1, thereby protecting the first comparator U1. The drain of the second metal-oxide-semiconductor transistor Q2 is coupled to the first input terminal of the second comparator U2 through the third voltage divider resistor R3. The first input terminal of the second comparator U2 is grounded through the fourth voltage divider resistor R4. The third and fourth voltage divider resistors R3 and R4 divide the source-drain voltage V1 of the second metal-oxide-semiconductor transistor Q2, thereby protecting the second comparator U2.

[0046] In some embodiments, optionally, the first threshold voltage Vref1 is the product of the first maximum operating source-drain voltage V1 of the first metal-oxide-semiconductor transistor Q1 and the first voltage division ratio, the first voltage division ratio being the ratio of the resistance of the second voltage dividing resistor R2 to the sum of the resistances of the first voltage dividing resistor R1 and the second voltage dividing resistor R2; the second threshold voltage Vref2 is the product of the second maximum operating source-drain voltage V1 of the second metal-oxide-semiconductor transistor Q2 and the second voltage division ratio, the second voltage division ratio being the ratio of the resistance of the fourth voltage dividing resistor R4 to the sum of the resistances of the third voltage dividing resistor R3 and the fourth voltage dividing resistor R4.

[0047] In this embodiment, the sum of the resistance values ​​of the first voltage divider resistor R1 and the second voltage divider resistor R2 is first calculated. Then, the ratio of the resistance value of the second voltage divider resistor R2 to the sum of the above resistance values ​​is calculated as the first voltage division ratio. Finally, the first threshold voltage Vref1 is set as the product of the first maximum operating source-drain voltage V1 of the first metal-oxide-semiconductor transistor Q1 and the first voltage division ratio. Simultaneously, the sum of the resistance values ​​of the third voltage divider resistor R3 and the fourth voltage divider resistor R4 is calculated. Then, the ratio of the resistance value of the fourth voltage divider resistor R4 to the sum of the above resistance values ​​is calculated as the second voltage division ratio. Finally, the second threshold voltage Vref2 is set as the product of the second maximum operating source-drain voltage V1 of the second metal-oxide-semiconductor transistor Q2 and the second voltage division ratio.

[0048] In some embodiments, optionally, such as Figure 1 As shown, the energy storage converter push-pull circuit 100 also includes a driver chip 114. The output pin of the controller 106 is coupled to the driver chip 114 to transmit a pulse width signal with a pulse width signal duty cycle to the driver chip 114 so as to control the driver chip 114 to turn the two metal oxide semiconductor transistors 102 on and off according to the pulse width signal duty cycle.

[0049] In this embodiment, the energy storage converter push-pull circuit 100 further includes a driver chip 114. The input terminal of the driver chip 114 is connected to the output pin of the controller 106. The controller 106 can transmit a pulse width signal with a duty cycle to the driver chip 114. The output terminal of the driver chip 114 is connected to the gates of two metal-oxide-semiconductor (MOSFETs) 102. The driver chip 114 can control the switching of the two MOSFETs 102 according to the pulse width signal with a duty cycle transmitted by the controller 106. By adding the driver chip 114 between the controller 106 and the two MOSFETs 102, the driving capability is enhanced, ensuring that the pulse width signal with a duty cycle issued by the controller 106 can effectively and quickly control the switching of the two MOSFETs 102.

[0050] For example, such as Figure 1 As shown, the energy storage converter push-pull circuit 100 also includes a sixth resistor R6 and a seventh resistor R7. The first end of the sixth resistor R6 is connected to the driver chip 114, and the second end of the sixth resistor R6 is connected to the gate of the first metal-oxide-semiconductor transistor Q1. This allows for current limiting of the electrical signal emitted by the driver chip 114, thereby protecting the first metal-oxide-semiconductor transistor Q1. Similarly, the first end of the seventh resistor R7 is connected to the driver chip 114, and the second end of the seventh resistor R7 is connected to the gate of the second metal-oxide-semiconductor transistor Q2. This also allows for current limiting of the electrical signal emitted by the driver chip 114, thereby protecting the second metal-oxide-semiconductor transistor Q2.

[0051] like Figure 1 As shown, the present invention proposes an energy storage converter 10, wherein the energy storage converter 10 includes: an energy storage converter push-pull circuit 100 as in any of the above embodiments; a rectifier 116, coupled to the secondary winding 120 of the transformer 104, for converting the AC boost voltage obtained by the energy storage converter push-pull circuit 100 for the DC output voltage of the energy storage battery 112 into a DC boost voltage; and an inverter circuit 118, coupled to the rectifier 116, for converting the DC boost voltage output by the rectifier 116 into an AC output voltage for supplying power to the load.

[0052] The energy storage converter 10 provided by this invention mainly includes: an energy storage converter push-pull circuit 100, a rectifier 116, and an inverter circuit 118. The energy storage converter push-pull circuit 100 is the same as described in any of the above embodiments. The rectifier 116 is coupled to the secondary winding 120 of the transformer 104, and the rectifier 116 can convert the DC output voltage of the energy storage battery 112 from the energy storage converter push-pull circuit 100 into an AC boost voltage. The inverter circuit 118 is coupled to the rectifier 116, and the inverter circuit 118 can convert the DC boost voltage output by the rectifier 116 into an AC output voltage, which then supplies power to the load.

[0053] Figure 2 A flowchart illustrating a push-pull control method for an energy storage converter according to an embodiment of the present invention is shown, wherein the push-pull control method for the energy storage converter includes:

[0054] Step 202: In response to the connection of the energy storage battery, gradually increase the duty cycle of the pulse width signal controlling the opening and closing of the metal oxide semiconductor transistor, thereby controlling the source-drain voltage on the drain of the metal oxide semiconductor transistor.

[0055] Step 204: If the source-drain voltage is greater than the threshold voltage, change the pulse width signal duty cycle to a second value, wherein the second value is less than or equal to the first value, and the first value is the value of the pulse width signal duty cycle when the source-drain voltage is greater than the threshold voltage.

[0056] The push-pull control method for energy storage converters provided by this invention is mainly used in push-pull circuits of energy storage converters. The push-pull circuit includes two metal-oxide-semiconductor (MOS) transistors, a transformer, a controller, and a source-drain voltage detection component. The sources of the two MOS transistors are grounded, and their drains are coupled to the first and second terminals of the primary winding of the transformer, respectively. The center tap of the primary winding of the transformer is coupled to a storage battery, meaning the positive terminal of the storage battery is connected to the center tap of the primary winding of the transformer, and the negative terminal of the storage battery is connected to ground. The signal output port of the controller is connected to the gates of the two MOS transistors, and the controller can output pulse signals through the signal output port to control the conduction and disconnection of the two MOS transistors. The drains of the two metal-oxide-semiconductor transistors are coupled to the input of the source-drain voltage detection component, and the output of the source-drain voltage detection component is coupled to the controller. The source-drain voltage detection component can detect the source-drain voltage of the two metal-oxide-semiconductor transistors, compare the detected source-drain voltage with the threshold voltage, and output the comparison result to the controller so that the controller controls the two metal-oxide-semiconductor transistors according to the comparison result.

[0057] The push-pull control method for energy storage converters includes the following steps: After the energy storage battery is connected, the duty cycle of the pulse width signal controlling the switching of the metal-oxide-semiconductor (MOSFET) is gradually increased to achieve soft start, while simultaneously controlling the source-drain voltage at the drain of the MOSFET. Subsequently, the source-drain voltage detection component compares the detected source-drain voltage with a threshold voltage. When the source-drain voltage at the drain of either of the two MOSFETs exceeds the threshold voltage, the duty cycle of the pulse width signal is changed to a second value, where the second value is less than or equal to the first value. The first value is the pulse width signal duty cycle value when the source-drain voltage is greater than the threshold voltage. In other words, when the source-drain voltage is greater than the threshold voltage, the pulse width signal duty cycle is reverted to its previous value. Then, when the source-drain voltage is less than the threshold voltage, the pulse width signal duty cycle is gradually increased. This fully utilizes the voltage withstand capability of the MOSFET, reduces start-up time, and ensures the safety of the MOSFET. Meanwhile, when the maximum source-drain voltage tolerance of various metal-oxide-semiconductor transistors differs due to process variations, this invention can flexibly adapt to metal-oxide-semiconductor transistors with different processes by backing down based on the actual detected source-drain voltage and threshold voltage relationship.

[0058] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance, unless otherwise expressly specified and limited. The terms "connection," "installation," and "fixing," etc., should be interpreted broadly. For example, "connection" can mean a fixed connection, a detachable connection, or an integral connection; it can mean a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0059] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which 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.

[0060] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A push-pull circuit for an energy storage converter, characterized in that, The device includes two metal-oxide-semiconductor (MOS) transistors with their sources grounded, a transformer, a controller, and a source-drain voltage detection component. The drains of the two MOS transistors are respectively coupled to the first and second ends of the primary winding of the transformer. The center tap of the primary winding of the transformer is used to couple an energy storage battery to ground. The controller is respectively coupled to the gates of the two MOS transistors. The drains of the two MOS transistors are coupled to the input terminal of the source-drain voltage detection component. The output terminal of the source-drain voltage detection component is coupled to the controller. In response to the connection of the energy storage battery, the controller gradually increases the duty cycle of the pulse width signal controlling the opening and closing of the metal oxide semiconductor transistor, thereby controlling the source-drain voltage on the drain of the metal oxide semiconductor transistor. The source-drain voltage detection component compares the source-drain voltage with a threshold voltage. If the source-drain voltage is greater than the threshold voltage, the controller is triggered to change the duty cycle of the pulse width signal to a second value, wherein the second value is less than or equal to the first value, and the first value is the value of the duty cycle of the pulse width signal when the source-drain voltage is greater than the threshold voltage.

2. The energy storage converter push-pull circuit according to claim 1, characterized in that, The controller periodically changes the duty cycle of the pulse width signal, wherein the controller is specifically configured to: set the second value of the second cycle after the first cycle to be equal to the first value, wherein the first cycle is the cycle in which the source-drain voltage is detected to be greater than the threshold voltage; and set the second value of the third cycle after the second cycle to be less than the first value.

3. The energy storage converter push-pull circuit according to claim 2, characterized in that, The second value is the product of the first value and a predetermined ratio, where the predetermined ratio is a positive number less than 1.

4. The energy storage converter push-pull circuit according to claim 1, characterized in that, After changing the duty cycle of the pulse width signal to the second value, the controller continues to gradually increase the duty cycle of the pulse width signal until the duty cycle of the pulse width signal reaches the target value.

5. The energy storage converter push-pull circuit according to claim 1, characterized in that, The two metal-oxide-semiconductor transistors include a first metal-oxide-semiconductor transistor and a second metal-oxide-semiconductor transistor; the source-drain voltage detection component includes a first comparator and a second comparator; the threshold voltage includes a first threshold voltage and a second threshold voltage; the first input terminal of the first comparator is coupled to the drain of the first metal-oxide-semiconductor transistor, the second input terminal of the first comparator is coupled to the first threshold voltage, and the output terminal of the first comparator is coupled to the input pin of the controller. The first input terminal of the second comparator is coupled to the drain of the second metal-oxide-semiconductor transistor, the second input terminal of the second comparator is coupled to the second threshold voltage, and the output terminal of the second comparator is coupled to the input pin of the controller.

6. The energy storage converter push-pull circuit according to claim 5, characterized in that, The source-drain voltage detection component includes a first voltage divider resistor, a second voltage divider resistor, a third voltage divider resistor, and a fourth voltage divider resistor; The drain of the first metal-oxide-semiconductor transistor is coupled to the first input terminal of the first comparator through the first voltage divider resistor, and the first input terminal of the first comparator is grounded through the second voltage divider resistor; the drain of the second metal-oxide-semiconductor transistor is coupled to the first input terminal of the second comparator through the third voltage divider resistor, and the first input terminal of the second comparator is grounded through the fourth voltage divider resistor.

7. The energy storage converter push-pull circuit according to claim 6, characterized in that, The first threshold voltage is the product of the first maximum operating source-drain voltage of the first metal-oxide-semiconductor transistor and the first voltage division ratio, and the first voltage division ratio is the ratio of the second voltage dividing resistor to the sum of the resistances of the first voltage dividing resistor and the second voltage dividing resistor; the second threshold voltage is the product of the second maximum operating source-drain voltage of the second metal-oxide-semiconductor transistor and the second voltage division ratio, and the second voltage division ratio is the ratio of the fourth voltage dividing resistor to the sum of the resistances of the third voltage dividing resistor and the fourth voltage dividing resistor.

8. The energy storage converter push-pull circuit according to claim 1, characterized in that, It also includes a driver chip, the output pin of the controller is coupled to the driver chip, and is used to transmit a pulse width signal with the pulse width signal duty cycle to the driver chip to control the driver chip to turn the two metal oxide semiconductor transistors on and off according to the pulse width signal duty cycle.

9. An energy storage converter, characterized in that, include: The energy storage converter push-pull circuit as described in any one of claims 1-8; A rectifier, coupled to the secondary winding of the transformer, is used to convert the AC boost voltage obtained by the push-pull circuit of the energy storage converter for the DC output voltage of the energy storage battery into a DC boost voltage. An inverter circuit, coupled to the rectifier, is used to convert the DC boost voltage output by the rectifier into an AC output voltage to power the load.

10. A push-pull control method for an energy storage converter, characterized in that, A push-pull circuit for an energy storage converter, the push-pull circuit including two metal-oxide-semiconductor (MOS) transistors with their sources grounded, a transformer, and a source-drain voltage detection component, wherein the drains of the two MOS transistors are respectively coupled to a first terminal and a second terminal of the primary winding of the transformer, the center tap of the primary winding of the transformer is used to couple an energy storage battery to ground, and the drains of the two MOS transistors are coupled to the source-drain voltage detection component, the push-pull control method for the energy storage converter including: In response to the connection of the energy storage battery, the duty cycle of the pulse width signal controlling the opening and closing of the metal oxide semiconductor is gradually increased, thereby controlling the source-drain voltage on the drain of the metal oxide semiconductor. If the source-drain voltage is greater than the threshold voltage, the duty cycle of the pulse width signal is changed to a second value, wherein the second value is less than or equal to the first value, and the first value is the value of the duty cycle of the pulse width signal when the source-drain voltage is greater than the threshold voltage.

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