A grid-source feedback parallel current sharing circuit and method for energy storage converter power devices

Abstract

The application provides a kind of energy storage converter power device grid source feedback parallel current sharing circuit and method, belong to power electronics technical field.The application realizes the transient current balance when power device is parallel, avoids the risk that part of device is damaged due to bearing excessive current stress, effectively prolongs the service life of device, improves the reliability of entire power electronic system.Meanwhile, stable current balance can also reduce the electromagnetic interference caused by current imbalance, improve the anti-interference ability of system.Active gate control technology can dynamically adjust current change rate according to actual current condition, so that the switching speed of parallel power device is more matched, energy loss in switching process is reduced, and the efficiency of system is improved.In addition, stable current balance helps to improve the dynamic response performance of system, reduce the ripple of output voltage and current, and improve the power quality and overall performance of system.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of power electronics, and particularly relates to current balancing technology in parallel application of power devices, and is especially suitable for parallel use of power switching tubes and other power devices, and is widely applied to occasions requiring high power density and high reliability, such as electric vehicle power systems, industrial motor drives, power system power conversion, etc. BACKGROUND

[0002] In order to meet the high power requirement of energy storage converters, parallel technology of high-power devices has become a common solution. For example, in some medium and large energy storage systems, multiple insulated gate bipolar transistors (IGBTs) or silicon carbide metal oxide semiconductor field effect transistors (power switching tubes) and other high-power devices are often used in parallel operation. However, this parallel mode faces many challenges. There are certain differences in the manufacturing process of high-power devices, and even devices produced in the same batch have difficulty in being completely consistent in parameters such as on-resistance and threshold voltage. In addition, circuit parasitic parameters such as line inductance and capacitance have a significant impact on current distribution in the parallel circuit. These factors combined together lead to the current imbalance phenomenon between the parallel high-power devices in actual operation.

[0003] Current imbalance can bring a series of serious problems to energy storage converters. Current imbalance is particularly prominent during switching transient process. Some devices that bear larger current will generate excessive heat, causing the junction temperature to rise. In this state for a long time, the aging speed of the device is accelerated, greatly increasing the risk of device damage, thereby reducing the reliability of the energy storage converter. Moreover, current imbalance can also cause additional energy loss, reduce the overall conversion efficiency of the system, and increase the operating cost of the system. At present, for the current imbalance problem of parallel large power devices, the existing driving technology has certain limitations. The passive method such as device screening can select devices with relatively close parameters, but this method is costly and time-consuming, and lacks practicality in large-scale production and application scenarios. The symmetric circuit layout is limited by the physical structure of the actual circuit board, and it is difficult to achieve complete symmetry, especially when multiple large power devices are connected in parallel. It is almost impossible to ensure that the parasitic parameters of each device are completely consistent. Coupled inductors can suppress dynamic current imbalance to some extent, but they are relatively large in size, and as the number of parallel devices increases, the number and cost of inductors required will increase significantly. In the active method, the traditional active gate driver (AGD) technology also has some problems. Some AGD methods require high-bandwidth current sensors, which not only increases the system cost, but also puts higher requirements on the installation and layout of the sensors. Some AGD methods have slow response speed and cannot adapt to the fast switching requirements of large power devices, resulting in large current imbalance during the switching transient process. In addition, some AGD methods have complex control circuits and are difficult to extend to multiple parallel devices, limiting their application range in actual energy storage converter engineering. In summary, in the energy storage converter, the current imbalance problem of parallel large power devices seriously affects the system performance and reliability, and the existing driving technology cannot effectively solve these problems, so there is an urgent need for a new and efficient driving optimization technology to improve this situation. SUMMARY

[0004] In view of the current imbalance problem existing in the existing parallel power device technology, especially the reliability reduction and efficiency loss caused by switching transient current imbalance when power switch tubes are connected in parallel, the present application provides a simple and efficient, fast response and easy to extend to multiple parallel devices current balancing technology to achieve transient current balancing when power devices are connected in parallel, and improve the reliability and overall performance of the system.

[0005] In order to achieve the above-mentioned purpose, the technical scheme provided by the present application is as follows:

[0006] In a first aspect, the present application provides a power device gate-source feedback parallel current balancing circuit for an energy storage converter, comprising a gate-source feedback circuit main circuit, a gate drive circuit of a power switch tube and an active gate control circuit. The gate-source feedback circuit main circuit is connected in parallel with the gate drive circuit of the power switch tube and the active gate control circuit, and the gate drive circuit of the power switch tube is connected in parallel with the active gate control circuit. and the load inductor L in parallel, two power devices are marked as and in parallel, and the source inductors and and the parasitic inductors and in parallel; wherein the power devices in the branch , , are in series connection in turn, and the power devices in the branch , , are also in series connection in turn; the connection mode of the gate-source feedback circuit is direct current voltage , the branch composed of the freewheeling diode D and the load inductor L in parallel, the branch of the power device and the power switch tube in parallel are in series connection in turn;

[0007] The gate drive circuit comprises a gate resistor , a source resistor and a driving voltage pulse ; the connection mode of the gate drive circuit is that the gate of each power device is connected to the driving voltage source through a gate resistor , the source is connected to the ground after being connected in series with a source resistor , and the drain is connected to the branch composed of the freewheeling diode D and the load inductor L in parallel;

[0008] The active gate control circuit comprises a bipolar junction transistor and , resistors and , diodes VD1 and VD2; the connection mode of the active gate control circuit is that the gate of the power device is connected to one end of the diode VD1, the other end of the diode VD1 is connected to the collector of the bipolar junction transistor , the base of the bipolar junction transistor is connected to the source S1 of the power device , the emitter of the bipolar junction transistor is connected to the resistor , the resistor is connected to the source S2 of the power device ; the gate of the power device is connected to one end of the diode VD2, and the diode VD1 is connected to the bipolar junction transistor collector, bipolar junction transistor Base-connected power devices The source S1 is a bipolar junction transistor. emitter connection resistor One end, resistor The other end power device The source pole S2.

[0009] Furthermore, the active gate control circuit is based on the feedback operation of the gate-source feedback circuit main circuit for the power device, including:

[0010] when Opening faster than hour, Work makes The gate current decreases, and the formula for decreasing the current is:

[0011]

[0012] in, for The absorbed current, for The source inductor voltage at that point, for The source inductor voltage at that point, It is the base-emitter turn-on voltage of a bipolar junction transistor;

[0013] when Opening faster than At that time, Q2 works, making The gate current decreases, and the formula for decreasing the current is:

[0014]

[0015] in, for The absorbed current, for The source inductor voltage at that point, for The source inductor voltage at that point, It is the base-emitter turn-on voltage of a bipolar junction transistor.

[0016] Furthermore, the resistance of the active gate control circuit and The design satisfies the following formula:

[0017]

[0018] in, for The source inductor voltage at that point, Vce is the source inductance voltage at the source of the power device, is the base-emitter on voltage of the bipolar junction transistor, is the maximum output current required by the active gate control circuit.

[0019] In a second aspect, the present application provides a method for grid-source feedback parallel current sharing of power devices of an energy storage converter, applied to a grid-source feedback parallel current sharing circuit of the energy storage converter as in the first aspect, comprising the following steps:

[0020] S1: the active gate control circuit monitors the source inductance voltage of the power device in real time, and obtains the source inductance voltage of the power device , The current change rate of the two branches;

[0021] S2: compare the source inductance voltage of the branch , with the reference voltage and with the reference voltage , , , , , , ,

[0022] S3: the active gate control circuit works to control the gate current of , , , , , , , , , , , ;

[0023] S4: adjust the turn-on and turn-off speed through the feedback of the source resistance, when and the power device works, the source current flows through the source resistance and , generating voltage drops and ; and are introduced into the gate drive circuit as feedback signals, interact with the gate voltage, and further adjust and The on and off speed of the source current to the balance state adjustment.

[0024] Further, in S1, the formula of the current rate of change is as follows:

[0025]

[0026] Wherein and Respectively , The source inductance voltage of Respectively , Two branch current rate of change The source inductance.

[0027] Further, in S2, the formula of the reference voltage is as follows:

[0028]

[0029] Wherein The number of source inductance of all parallel devices The source inductance voltage of the first

[0030] Further, in S3, the absorption current generated by the active gate control circuit and The formula is as follows:

[0031]

[0032] Wherein, and The source inductance voltage of power devices and , The reference voltage of the source inductance of the power device; The base-emitter on voltage of the bipolar junction transistor; and The resistance connected between the emitter of the bipolar junction transistor and the source of the power device.

[0033] Further, in S4, the on and off speed of and Adjustment, including:

[0034] and The two voltage drops are introduced into the gate drive circuit as feedback signals, which interact with the gate voltage, and ​The pressure drop calculation formula is as follows:

[0035]

[0036] When The ratio When the conduction is fast, The source inductance voltage Greater than The source inductance voltage , between Current The current Direction is from the source Point to the source Point, current Flow through , resulting in voltage drop And , Will make The gate-source voltage Lower conduction speed slows down, The calculation formula is:

[0037]

[0038] The driving voltage, Will make The gate-source voltage Rise conduction speed becomes fast, The calculation formula is:

[0039]

[0040] The conduction speed gradually slows down, while The conduction speed is constantly accelerated, after a series of dynamic changes, eventually making And The conduction speed tends to be consistent.

[0041] Further, the resistance value of the source resistance is selected according to the rated current, switching speed and desired current balance accuracy of the power device, and the source resistance calculation is according to the following formula:

[0042]

[0043] Wherein, The source resistance value, The rated current of the power device, The threshold voltage of the power device, The current rise time, The allowable current imbalance.

[0044] Further, the source inductance For detecting the current rate of change, the detection voltage needs to meet the minimum requirement for the normal operation of the feedback circuit. The feedback circuit in the active gate control circuit is based on a bipolar junction transistor. The source inductance detection voltage needs to meet certain requirements. The base-emitter on voltage of the bipolar junction transistor is The peak current of the two parallel power switch tubes is and The average static current is The current rise time is , The peak current mismatch rate is and The current rise rate and The calculation formula is:

[0045]

[0046] For the current absorption circuit, when Turn on faster than At this time > The necessary condition for normal operation is:

[0047]

[0048] Substitute the current rise rate expression into the above formula to obtain the calculation formula of the minimum source inductance:

[0049]

[0050] The bandwidth of the bipolar junction transistor is The calculation formula is:

[0051]

[0052] Where is the current rise time.

[0053] Further, when there is a difference in the source inductance, The current rate of change The calculation formula is:

[0054]

[0055] The voltage difference caused by the source inductance is less than The formula is:

[0056]

[0057] wherein is the average quiescent current, is the current rise time, is the source inductance difference, is the base-emitter on voltage.

[0058] In summary, the application provides a grid-source feedback parallel current sharing circuit and method for energy storage converter power devices, which achieves transient current balance when power devices are connected in parallel, avoiding the risk of damage to some devices due to excessive current stress, effectively prolonging the service life of the devices and improving the reliability of the entire power electronic system. At the same time, stable current balance can also reduce electromagnetic interference caused by current imbalance and improve the anti-interference ability of the system. Active gate control technology can dynamically adjust the current change rate according to the actual current situation, making the switching speed of parallel power devices more matched, reducing energy loss during switching and improving the efficiency of the system. In addition, stable current balance helps to improve the dynamic response performance of the system, reduce the ripple of output voltage and current, and improve the power quality and overall performance of the system. BRIEF DESCRIPTION OF DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0060] Figure 1 The grid-source feedback parallel current sharing circuit for energy storage converter power devices provided by the embodiment of the present application is shown in the figure;

[0061] Figure 2 The active gate control circuit schematic diagram provided by the embodiment of the present application is shown in the figure;

[0062] Figure 3 The turn-on stage current comparison graph before using the current sharing method provided by the embodiment of the present application is shown in the figure;

[0063] Figure 4 The turn-on stage current comparison graph after using the current sharing method provided by the embodiment of the present application is shown in the figure;

[0064] Figure 5 The turn-off stage current comparison graph before using the current sharing method provided by the embodiment of the present application is shown in the figure;

[0065] Figure 6 The turn-off stage current comparison graph after using the current sharing method provided by the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0066] In order to make the purposes, features and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings of the embodiments of the present application. Obviously, the following described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0067] The embodiment of the present application provides a kind of energy storage converter power device grid source feedback parallel current sharing circuit, the circuit uses the parallel circuit structure of power device based on source resistance feedback and active gate control circuit control, as shown in Figure 1 The gate-source feedback circuit of the parallel power device in the embodiment is composed of gate-source feedback circuit main circuit, gate drive loop of power switch tube, active gate control circuit;Gate-source feedback circuit main circuit is composed of the branch of DC voltage , freewheeling diode D and load inductance L in parallel, two power switch tubes are marked as To and In parallel, source inductance And And parasitic inductance And Composition, wherein power device Branch , , Is in turn in series, power device Branch , , It is also in turn in series;Gate-source feedback circuit main circuit connection mode is composed of the branch of DC voltage , freewheeling diode D and load inductance L in parallel, power device Branch and power switch tube Branch in parallel composition branch is in turn in series;Gate drive loop includes gate resistance And , source resistance , And drive voltage pulse ;The connection mode of gate drive loop is that the gate of each power device is connected to drive voltage source Through a gate resistance , source is connected to ground after being connected in series with a source resistance , drain is connected to the branch of freewheeling diode D and load inductance L in parallel.

[0068] The principle of active gate control circuit is as followsFigure 2 As shown, the active gate control circuit includes a bipolar junction transistor. and ,resistance and Diodes VD1 and VD2; the connection method of the active gate control circuit is as follows: Power devices with active gate control circuits gate Connect one end of diode VD1, and connect the other end of diode VD1 to a bipolar junction transistor. collector, bipolar junction transistor Base-connected power devices The source pole Bipolar junction transistor emitter connection , Connecting power devices The source electrode S2; Power devices with active gate control circuits gate One end of diode VD2 is connected, and diode VD1 is connected to a bipolar junction transistor. collector, bipolar junction transistor Base-connected power devices The source S1 is a bipolar junction transistor. emitter connection One end, The other end power device The source pole S2.

[0069] This invention also provides a method for parallel current sharing of gate-source feedback in power devices of an energy storage converter, the steps of which are as follows:

[0070] S1, the active gate control circuit monitors the voltage across the source inductor of the power device in real time, and obtains the voltage across the source inductor of the power device in real time. , The rate of change of current in both branches; the formula for calculating the rate of change of current obtained from the source inductor is expressed as:

[0071] (1)

[0072] in and They are respectively , The source inductor voltage, They are respectively , The rate of change of current in the two branches Source inductor;

[0073] S2, the , source inductance voltage of the branch and is compared with a reference voltage bipolar junction transistor in the active gate control circuit and the and is compared with when > , the rate of current change is large, when > , the rate of current change is large; two power devices , parallel control strategy, at the active gate control circuit of is equal to , at the active gate control circuit of is equal to ; in the control strategy of multiple power devices in parallel, the average control strategy is adopted, the average value of the source inductance of all parallel devices is calculated, and the average value calculation formula is represented as:

[0074] (2)

[0075] It is used as a reference signal, and the gate drive current is adjusted according to the comparison result of each device and , so that the current change rate of each device tends to the average value.

[0076] S3, active gate control circuit working control , the gate current of > At this time the rate of current change is greater than the reference value, and the gate current at needs to be reduced, the active gate control circuit generates a sink current to reduce the gate current at , > At this time the rate of current change is greater than the reference value, and the gate current at needs to be reduced, the active gate control circuit generates a sink current to reduce the gate current at Gate current at the location.

[0077] In a further embodiment, the active gate control circuit generates a sink current. and The calculation formula is expressed as follows:

[0078] (2)

[0079] in, and Indicates power devices and The voltage across the source inductor reflects the rate of change of the source current. It is the reference voltage across the source inductor of the power device, used to compare with the actual detected voltage across the source inductor to determine whether the current change is too fast; It is the base-emitter turn-on voltage of a bipolar junction transistor (BJT), which is the voltage drop between the base and emitter when the BJT is operating normally. This voltage value plays an important role in calculating the current absorption, because it, together with the voltage across the source inductor and the reference voltage, determines the degree of current absorption. and The resistor is used to determine the relationship between the magnitude of the absorption current and the voltage difference. The value of the resistor affects the effect of the absorption current on the adjustment of the gate drive current.

[0080] S4 adjusts the turn-on and turn-off speeds via source resistor feedback. and When a power device is operating, the source current... Current flows through the source resistor and This causes a pressure drop. and .

[0081] In a further embodiment, and The formula for calculating the pressure drop is expressed as:

[0082] (4)

[0083] and This voltage drop is introduced as a feedback signal into the gate drive circuit and interacts with the gate voltage; when Compare When conduction is fast, Source inductor voltage Greater than Source inductor voltage ,exist Current is generated between Current The direction is from the source pole The current flows from point S2 to the source point S2. Flowing This causes a pressure drop. and , It will make Gate-source voltage Reducing the conduction speed slows down. The calculation formula is expressed as:

[0084] (5)

[0085] For driving voltage, It will make Gate-source voltage Reduced conduction speed leads to faster conduction. The calculation formula is expressed as:

[0086] (6)

[0087] The conduction speed gradually slows down, while The conduction speed continuously increases, and after a series of dynamic changes, it eventually becomes... and The conduction speeds are almost uniform, causing the source current to adjust towards a balanced state.

[0088] In some other embodiments of the present invention, design methods for some important parameters are also provided, including:

[0089] Source resistance is calculated using the following formula:

[0090] (7)

[0091] in, The source resistor value is... This refers to the rated current of the power device. The threshold voltage of the power device. The current rise time To account for the allowable current imbalance, the power capacity of the source resistor is selected based on the operating current and voltage of the power device to ensure that it will not be damaged by overheating under normal operation and overload conditions.

[0092] Source Inductor For detecting the rate of change of current, the detection voltage must meet the minimum requirements for normal operation of the feedback circuit. The feedback circuit in the active gate control circuit is based on a bipolar junction transistor (BJT), and the source inductor detection voltage must meet certain requirements. The base-emitter turn-on voltage of the BJT is... The peak current of two parallel power switch tubes is and The average quiescent current is The current rise time is , The peak current mismatch rate is and The current rise rate is and The calculation formula is:

[0093] (8)

[0094] For the current absorption circuit, when Turn on faster than At this time > The necessary condition for normal operation is:

[0095] (9)

[0096] Substitute the current rise rate expression into the above formula to obtain the calculation formula of the minimum source inductance:

[0097] (10)

[0098] The bandwidth of the bipolar junction transistor is The calculation formula is:

[0099] (11)

[0100] Where is the current rise time.

[0101] When the source inductance difference , The current change rate of The calculation formula is:

[0102] (12)

[0103] The voltage difference caused by the source inductance is less than The formula is:

[0104] (13)

[0105] Where is the average quiescent current, is the current rise time, is the source inductance difference, is the base-emitter on voltage.

[0106] Resistance of active gate control circuit and The design needs to meet:

[0107] (14)

[0108] Wherein and represent the source inductance voltage of power devices and , is the base-emitter on voltage of bipolar junction transistor, is the maximum output current required by the active gate control circuit.

[0109] Figures 3-6 The application effect of the energy storage converter power device gate-source feedback parallel current sharing circuit and method in specific circuit is presented. These results are measured by an oscilloscope, which shows the branch current and on the turn-on stage and turn-off stage and without using the current sharing method, and also shows the branch current and on the turn-on stage and turn-off stage and after using the current sharing method. By comparing these waveform diagrams, it can be seen that the current imbalance degree on the turn-on stage and turn-off stage is significantly reduced after using the current sharing method, and the current imbalance degree The formula for

[0110] (15)

[0111] Wherein is the current imbalance degree, and are the branch currents on and , is the maximum value of and .

[0112] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A gate-source feedback parallel current sharing circuit for power devices in an energy storage converter, comprising a main circuit for the gate-source feedback circuit, a gate drive circuit for the power switch, and an active gate control circuit, characterized in that, The main circuit of the gate-source feedback circuit is powered by a DC voltage. A branch consisting of a freewheeling diode D and a load inductor L connected in parallel, power devices and power devices The parallel branch, and the source inductor in the parallel branch. and and parasitic inductance and Composition; including power devices Parasitic inductance in branch circuit Power devices Source inductor They are connected in series, power devices Parasitic inductance in branch circuit Power devices Source inductor They are also connected in series; the connection method of the gate-source feedback circuit is the DC voltage. A branch consisting of a freewheeling diode D and a load inductor L connected in parallel; power devices. Branch circuits and power switching transistors Branches connected in parallel are connected in series. The gate drive circuit includes a gate resistor. and Source resistance and Drive voltage pulse The connection method of the gate drive circuit is a power device. and power devices The gates are respectively connected through the gate resistor. and Connected to drive voltage pulse Power devices and power devices The source terminals are connected in series with source resistors. and Rear grounding, power devices and power devices The drains are respectively connected to the branch formed by the freewheeling diode D and the load inductor L in parallel; The active gate control circuit includes a bipolar junction transistor. and ,resistance and Diodes VD1 and VD2; the active gate control circuit is connected as a power device. gate Connect one end of diode VD1, and connect the other end of diode VD1 to a bipolar junction transistor. collector, bipolar junction transistor Base-connected power devices The source S1 is a bipolar junction transistor. emitter connection resistor One end, resistor The other end is connected to the power device Source S2; power device gate Connect one end of diode VD2, and connect the other end of diode VD2 to a bipolar junction transistor. collector, bipolar junction transistor Base-connected power devices The source S2 is a bipolar junction transistor. emitter connection resistor One end, resistor The other end is connected to the power device The source electrode S1; When power devices and power devices During operation, the source current and Current flows through the source resistor and This causes a pressure drop. and Pressure drop and It is introduced into the gate drive circuit as a feedback signal, interacts with the gate voltage, and thus adjusts the power device. and power devices The speed at which the source is turned on and off adjusts the source current toward a balanced state.

2. The gate-source feedback parallel current sharing circuit for the power device of the energy storage converter according to claim 1, characterized in that, The active gate control circuit is based on the feedback operation of the gate-source feedback circuit main circuit for the power device, including: When power devices Turn-on faster than power devices At that time, bipolar junction transistor Working, enabling power devices The gate current decreases, and the formula for decreasing the current is: ； in, Bipolar junction transistor The absorbed current, For power devices The source inductor voltage at that point, For power devices The source inductor voltage at that point, It is the base-emitter turn-on voltage of a bipolar junction transistor. For resistors The resistance value; When power devices Turn-on faster than power devices At this time, the bipolar junction transistor Q2 operates, enabling the power device... The gate current decreases, and the formula for decreasing the current is: ； in, Bipolar junction transistor The absorbed current, For power devices The source inductor voltage at that point, For power devices The source inductor voltage at that point, It is the base-emitter turn-on voltage of a bipolar junction transistor. For resistors The resistance value.

3. The gate-source feedback parallel current sharing circuit for power devices in an energy storage converter according to claim 1, characterized in that, The resistor of the active gate control circuit and The design satisfies the following formula: ； in, For power devices The source inductor voltage at that point, For power devices The source inductor voltage at that point, It is the base-emitter turn-on voltage of a bipolar junction transistor. This is the maximum output current required by the active gate control circuit.

4. A method for parallel current sharing via gate-source feedback of power devices in an energy storage converter, applied to the parallel current sharing circuit via gate-source feedback of power devices in an energy storage converter as described in any one of claims 1-3, characterized in that, Includes the following steps: S1: The active gate control circuit monitors the voltage across the source inductor of the power device in real time to obtain the power device's... Power devices The rate of change of current in the two branches; S2: Power devices Power devices Source inductor voltage of the branch and With reference voltage When comparing, > Power devices The rate of change of current is large, when > Power devices The rate of change of current is large; S3: The active gate control circuit operates, controlling the power devices. Power devices The gate current, when > The active gate control circuit generates a sink current. Reduce power devices Gate current at, when > The active gate control circuit generates a sink current. Reduce power devices Gate current at; S4: The turn-on and turn-off speeds are adjusted via feedback from the source resistor when the power device... and power devices During operation, the source current and Current flows through the source resistor and This causes a pressure drop. and Pressure drop and It is introduced into the gate drive circuit as a feedback signal, interacts with the gate voltage, and thus adjusts the power device. and power devices The speed at which the source is turned on and off adjusts the source current toward a balanced state.

5. The method for parallel current sharing of gate-source feedback in a power device of an energy storage converter according to claim 4, characterized in that, In S1, the formula for calculating the rate of change of current is as follows: ； in and Power devices and power devices The source inductor voltage, Power devices and power devices The rate of change of current in the two branches and Power devices and power devices The source inductance in the two branches.

6. The method for parallel current sharing of gate-source feedback in a power device of an energy storage converter according to claim 4, characterized in that, In S2, the formula for calculating the reference voltage is as follows: ； in The number of source inductors for all parallel devices. For the first The source inductor voltage.

7. The method for parallel current sharing of gate-source feedback in a power device of an energy storage converter according to claim 4, characterized in that, In S3, the active gate control circuit generates the absorption current. and The calculation formula is as follows: ； in, and Indicates power devices and power devices The voltage across the source inductor, It is the reference voltage across the source inductor of the power device; It is the base-emitter turn-on voltage of a bipolar junction transistor; and It is the resistor connected between the emitter of a bipolar junction transistor and the source of a power device.

8. The method for parallel current sharing of gate-source feedback in a power device of an energy storage converter according to claim 4, characterized in that, In S4, adjust the power device. and power devices The on and off speeds include: When power devices Power Specific Devices When the conduction speed is fast, power devices Source inductor voltage Greater power devices Source inductor voltage In power devices Source inductor in the branch Power devices Source inductor in the branch Source resistance and Current is generated between Current The direction is from the source pole Point flow to source Point, current Current flows through the source resistor This causes a pressure drop. and , and These two voltage drops are introduced into the gate drive circuit as feedback signals and interact with the gate voltage. and The formula for calculating the pressure drop is as follows: ； pressure drop This will make power devices Gate-source voltage Reducing the conduction speed slows down. The calculation formula is expressed as: ； For driving voltage, voltage drop This will make power devices Gate-source voltage The conduction speed increases with increasing elevation. The calculation formula is expressed as: ； Power devices The conduction speed gradually slows down, while the power device The conduction speed continuously increases, and after a series of dynamic changes, the power device ultimately achieves this. and power devices The conduction speeds are nearly identical.

9. The method for parallel current sharing of gate-source feedback in a power device of an energy storage converter according to claim 4, characterized in that, The value of the source resistor is selected based on the rated current of the power device, the switching speed, and the desired current balance accuracy. The source resistor is calculated according to the following formula: ； in, The source resistor value is... This refers to the rated current of the power device. This refers to the threshold voltage of the power device. The current rise time This refers to the permissible current imbalance.

10. The method for parallel current sharing of gate-source feedback in a power device of an energy storage converter according to claim 4, characterized in that, Source Inductor For detecting the rate of change of current, the detection voltage must meet the minimum requirements for normal operation of the feedback circuit. The feedback circuit in the active gate control circuit is based on a bipolar junction transistor (BJT), and the base-emitter turn-on voltage of the BJT is... The peak currents of the two parallel power switches are respectively and The average static current is The current rise time is , Peak current mismatch rate, and The rate of increase of current at a constant slope and The calculation formula is: ； For current absorption circuits, when power devices Turn-on faster than power devices ,at this time > The necessary conditions for normal operation are: ； Substituting the expression for the rate of rise of current into the above equation, we obtain the minimum source inductance. The calculation formula is as follows: ； Bandwidth of a bipolar junction transistor The calculation formula is: ； in This represents the current rise time.

11. The method for parallel current sharing of gate-source feedback in a power device of an energy storage converter according to claim 10, characterized in that, When there is a difference in source inductance At that time, power devices rate of change of current The calculation formula is: ； The voltage difference caused by the source inductance is less than The formula is: ； in The average quiescent current, The current rise time Due to the difference in source inductance, This is the base-emitter turn-on voltage.

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