Power conversion circuit, current sharing control method and electronic equipment

Abstract

The invention discloses a power conversion circuit, a current sharing control method and electronic equipment, and belongs to the technical field of power electronics, the power conversion circuit comprises a switch module, the switch module comprises a plurality of power switches connected in parallel and a plurality of driving units, and the driving units are connected with the power switches in a one-to-one correspondence manner; the driving unit comprises an impedance adjusting circuit, and the impedance adjusting circuit is configured to adjust the impedance of the driving unit correspondingly connected with each power switch based on the current of the plurality of power switches. According to the power conversion circuit provided by the embodiment of the invention, the current sharing problem after multiple tubes of the power switching device are connected in parallel can be improved, and the reliability of the circuit is improved.

Description

Technical Field

[0001] The embodiments of this application relate to the field of power electronics technology, and in particular to a power conversion circuit, a current sharing control method, and an electronic device. Background Technology

[0002] Power switching devices are now widely used in power electronics technology, including power factor correction, energy storage inverters, and photovoltaic inverters. In photovoltaic inverters, power switching devices play a core role in power conversion, and in high-power photovoltaic inverters, multiple power switching devices are often used in parallel. However, the current sharing problem of multiple power switching devices connected in parallel can easily affect the reliability of the equipment, thus requiring urgent solutions. Summary of the Invention

[0003] The purpose of the embodiments of this application is to provide a power conversion circuit, a current sharing control method, and an electronic device to improve the current sharing problem of multiple power switching devices connected in parallel and enhance the reliability of the device.

[0004] To address the aforementioned technical problems, embodiments of this application disclose the following technical solutions:

[0005] In a first aspect, a power conversion circuit is provided, comprising:

[0006] A switching module, comprising multiple power switches connected in parallel and multiple drive units, wherein each drive unit is connected to a power switch in a one-to-one correspondence.

[0007] The drive unit includes an impedance adjustment circuit configured to adjust the impedance of the drive unit to which each of the power switches is connected, based on the current of the plurality of power switches.

[0008] In conjunction with the first aspect, the impedance adjustment circuit includes a variable resistance circuit having an input terminal and an output terminal. The variable resistance circuit includes a first current limiting module and a second current limiting module, which are located between the input terminal and the output terminal.

[0009] In conjunction with the first aspect, the first current limiting module and the second current limiting module are connected in parallel, and the variable resistance circuit further includes a third current limiting module, which is connected in parallel with the first current limiting module.

[0010] In conjunction with the first aspect, the variable resistance circuit further includes a first control unit, which is connected in series with the third current limiting module, and the first control unit is configured to control the connection and disconnection of the third current limiting module.

[0011] In conjunction with the first aspect, the variable resistance circuit further includes a fourth current limiting module, which is connected in series with the first current limiting module.

[0012] In conjunction with the first aspect, the variable resistance circuit further includes a second control unit and a third control unit, the second control unit being connected in series with the fourth current limiting module, and the second control unit being configured to control the connection and disconnection of the fourth current limiting module;

[0013] The third control unit is connected in parallel with the second control unit and the fourth current limiting module, and the third control unit is configured to control the second control unit and the fourth current limiting module to short-circuit.

[0014] In conjunction with the first aspect, the variable resistance circuit further includes a first current-limiting module and a second current-limiting module. The first current-limiting module is connected to the third current-limiting module and is configured to limit the current flowing through the third current-limiting module at the output terminal. The second current-limiting module is connected to the second current-limiting module and is configured to limit the current flowing through the second current-limiting module at the output terminal.

[0015] In conjunction with the first aspect, the variable resistance circuit further includes a third current-limiting module and a fourth current-limiting module. The third current-limiting module is connected to the third current-limiting module and is configured to limit the current flowing through the input terminal. The fourth current-limiting module is connected to the second current-limiting module and is configured to limit the current flowing through the input terminal.

[0016] In conjunction with the first aspect, the variable resistance circuit further includes a first voltage regulator module, a second voltage regulator module, a third voltage regulator module, a fourth voltage regulator module, and a fifth voltage regulator module. The first voltage regulator module is connected in series with the third current limiting module, and the first voltage regulator module is configured to stabilize the current flowing through the third current limiting module.

[0017] The second voltage regulator module is connected to the first current limiting module, and the second voltage regulator module is configured to stabilize the current flowing through the first current limiting module;

[0018] The third voltage regulator module is connected to the second current limiting module, and the third voltage regulator module is configured to stabilize the current flowing through the second current limiting module;

[0019] The fourth voltage regulator module is connected to the fourth current limiting module, and the fourth voltage regulator module is configured to stabilize the current flowing through the fourth current limiting module;

[0020] The fifth voltage regulator module is connected to the third control unit, and the fifth voltage regulator module is configured to stabilize the current flowing through the third control unit.

[0021] In conjunction with the first aspect, the power conversion circuit further includes a processor unit connected to the first control unit, the second control unit, and the third control unit. The processor unit is configured to control the closing or opening of the first control unit, the second control unit, or the third control unit based on the maximum current value, the minimum current value, and the average current value flowing through the power switch.

[0022] In conjunction with the first aspect, the power conversion circuit further includes a data acquisition unit connected to the power switch, the data acquisition unit being configured to acquire the current flowing through the power switch.

[0023] In conjunction with the first aspect, the acquisition unit includes a current acquisition circuit, the current acquisition circuit includes an operational amplifier and peripheral circuitry, and the peripheral circuitry is connected to the operational amplifier.

[0024] The operational amplifier has a negative input terminal, which is configured to receive a reference voltage.

[0025] In conjunction with the first aspect, the power switch includes a transistor having an input terminal and a control terminal, the driving unit is connected to the control terminal, and the acquisition unit is connected to the input terminal.

[0026] In conjunction with the first aspect, the impedance adjustment circuit includes a variable resistor circuit, which includes a sliding rheostat.

[0027] The second aspect provides a current sharing control method for a power conversion circuit, applied to a power conversion circuit as described in any one of the first aspects; the method includes:

[0028] Acquire current signals from multiple power switches;

[0029] The first current value and the second current value are obtained based on the current signal;

[0030] The impedance of the corresponding drive unit is adjusted based on the first current value to reduce the current signal flowing through the power switch;

[0031] The impedance of the corresponding drive unit is adjusted based on the second current value to increase the current signal flowing through the power switch.

[0032] A third aspect provides an electronic device including a power conversion circuit as described in any one of the first aspects.

[0033] One of the above technical solutions has the following advantages or beneficial effects:

[0034] This application provides a power conversion circuit, including: a switching module comprising multiple power switches connected in parallel and multiple driving units, with each driving unit connected to a power switch in a one-to-one correspondence; each driving unit includes an impedance adjustment circuit configured to adjust the impedance of the driving unit connected to each power switch based on the current of the multiple power switches. The power conversion circuit provided by this application can improve the current sharing problem of multiple power switching devices connected in parallel, thereby improving the reliability of the circuit.

[0035] This application also provides a current sharing control method for a power conversion circuit, applicable to the power conversion circuit provided in any of the embodiments. The method includes: acquiring current signals from multiple power switches; acquiring a first current value and a second current value based on the current signals; adjusting the impedance of a corresponding driving unit based on the first current value to reduce the current signal flowing through the power switch; and adjusting the impedance of the corresponding driving unit based on the second current value to increase the current signal flowing through the power switch. The current sharing control method for the power conversion circuit provided in this application improves the current sharing problem after multiple power switches are connected in parallel by controlling the impedance of the corresponding driving unit through the current signals of the power switches, thereby improving the reliability of the circuit. Attached Figure Description

[0036] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0037] Figure 1 This is a schematic diagram of the connection structure of the power conversion circuit module provided in the embodiments of this application;

[0038] Figure 2 This is a schematic diagram of the circuit connection structure of the driving unit provided in Embodiment 1 of this application;

[0039] Figure 3 This is a schematic diagram of the circuit connection structure of the driving unit provided in Embodiment 2 of this application;

[0040] Figure 4 This is a schematic diagram of the circuit connection structure of the driving unit provided in Embodiment 3 of this application;

[0041] Figure 5 This is a schematic diagram of the connection structure of the power conversion circuit provided in the embodiments of this application;

[0042] Figure 6 This is a schematic diagram of the circuit connection structure of the acquisition unit provided in the embodiments of this application;

[0043] Figure 7 This is a schematic diagram of the connection structure of the variable resistor circuit provided in the embodiments of this application;

[0044] Figure 8This is a schematic diagram illustrating the steps of the current sharing control method for the power conversion circuit provided in an embodiment of this application. Detailed Implementation

[0045] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0046] Those skilled in the art have noted that IGBTs (Insulated Gate Bipolar Transistors) are widely used in power equipment such as power factor correction, energy storage inverters, and photovoltaic inverters; in photovoltaic inverter products, IGBTs are the core components for power conversion. In high-power photovoltaic inverters, multiple IGBTs are often used in parallel. Parallel connection of multiple transistors can increase the power rating of the inverter, and by replacing modules, equipment costs can be effectively reduced.

[0047] When using multiple IGBT transistors in parallel, the current sharing problem needs to be addressed, which includes static and dynamic aspects. Static current sharing is currently achieved by optimizing the saturation voltage drop V of the semiconductor devices. cesat With forward pressure drop U F In addition, manufacturing processes can reliably reduce the parameter differences of IGBTs; however, dynamic current sharing focuses on the turn-on and turn-off processes of IGBTs. During the turn-on and turn-off processes, it is very easy for one single tube in a parallel multi-tube configuration to have an excessively high current while another single tube has an excessively low current. If this state persists for a long time, the internal wafer junction temperature of the IGBT with excessive current will be too high, and the characteristics will gradually deteriorate, affecting the reliability of the IGBT.

[0048] The specific implementation methods of this application are illustrated below through examples:

[0049] like Figure 1As shown, this application provides a power conversion circuit, including: a switching module, which includes multiple power switches connected in parallel and multiple drive units, with each drive unit connected to a power switch in a one-to-one correspondence; each drive unit includes an impedance adjustment circuit, configured to adjust the impedance of the drive unit connected to each power switch based on the current of the multiple power switches. Specifically, the multiple power switches connected in parallel can be applied to a boost circuit or an inverter topology circuit. In the topology circuit, the number of power switches can be from 1 to N, where N is a positive integer. The current flowing through each power switch is collected, and the power switches with the largest and smallest currents are determined from the multiple currents. The impedance adjustment circuit can control the magnitude of the impedance according to the situation, so that if it is determined that the current of a certain power switch is too large, the current flowing through the power switch can be reduced by increasing the impedance corresponding to the impedance adjustment circuit; if it is determined that the current of a certain power switch is too small, the current flowing through the power switch can be increased by decreasing the impedance corresponding to the impedance adjustment circuit.

[0050] Understandably, adjusting the impedance of the circuit according to the current of the power switches enables current sharing among multiple power switches connected in parallel, thereby improving the reliability of the circuit.

[0051] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown in the embodiment of this application, the impedance adjustment circuit includes a variable resistor circuit, which has an input terminal and an output terminal. The variable resistor circuit includes a first current limiting module R. gon Second current limiting module R goff The first current limiting module R gon Second current limiting module R goff It is positioned between the input and output terminals. Specifically, the variable resistor circuit is connected to the power switch, and its input terminal receives the current flowing into the power switch, while its output terminal is connected to the power switch. First current limiting module R gon Second current limiting module R goff Used to limit the current flowing into the power switch, thereby controlling the magnitude of the current flowing through the power switch.

[0052] Understandably, by setting the first current limiting module R gon Second current limiting module R goff The current flowing into the power switch can be controlled, and current sharing is achieved when multiple power switches are connected in parallel, thereby improving the reliability of the circuit.

[0053] like Figure 2 , Figure 3 and Figure 4As shown in the embodiment of this application, the first current limiting module R gon Second current limiting module R goff The parallel, variable resistance circuit also includes a third current limiting module R. sw1 The third current limiting module R sw1 With the first current limiting module R gon Parallel connection. Specifically, according to Ohm's law, the total resistance decreases when multiple resistors are connected in parallel. Therefore, the third current-limiting module R... sw1 With the first current limiting module R gon Second current limiting module R goff By connecting them in parallel, the total impedance of the variable resistor circuit can be reduced, thereby increasing the current flowing through it. This is achieved by controlling the third current-limiting module R. sw1 The specific impedance value allows for precise control of the current magnitude. Therefore, if it is determined that the current of a certain power switch is too low, the third current limiting module R can be used to... sw1 With the first current limiting module R gon Second current limiting module R goff Parallel connection can increase the current flowing through the variable resistor circuit, thereby increasing the current flowing into the power switch and achieving current sharing after multiple power switches are connected in parallel.

[0054] Understandably, this can be achieved by setting a third current limiting module R. sw1 It can control the total impedance of a variable resistor circuit, and thus, if the total impedance of the variable resistor circuit is too high, a third current limiting module R is connected in parallel. sw1 This reduces the total impedance, thereby increasing the current flowing into the power switch.

[0055] like Figure 2 , Figure 3 and Figure 4 As shown in the embodiment of this application, the variable resistance circuit further includes a first control unit SW1, and the first control unit SW1 and the third current limiting module R sw1 In series, the first control unit SW1 is configured to control the third current limiting module R. sw1 The connection and disconnection are controlled by the first control unit SW1, which switches the variable resistor circuit between low and normal current conditions. When the first control unit SW1 is closed, the third current limiting module R... sw1 With the first current limiting module R gon Second current limiting module R goff Parallel connection; with the first control unit SW1 disconnected, the third current limiting module R sw1 With the first current limiting module R gon Second current limiting module R goff Disconnection occurs; at this time, the first current limiting module R... gon Second current limiting module Rgoff Maintain parallel connection.

[0056] It is understandable that the third current limiting module R is controlled by the first control unit SW1. sw1 With the first current limiting module R gon Second current limiting module R goff The connection relationship; when the current flowing through the power switch is too small, closing the first control unit SW1 can activate the third current limiting module R. sw1 With the first current limiting module R gon Second current limiting module R goff By connecting them in parallel, the impedance of the variable resistor circuit is reduced, thereby increasing the current flowing into the power switch.

[0057] like Figure 2 , Figure 3 and Figure 4 As shown in the embodiment of this application, the variable resistance circuit further includes a fourth current limiting module R. SW2 The fourth current limiting module R SW2 With the first current limiting module R gon Series connection. Specifically, according to Ohm's law, the total resistance increases when resistors are connected in series. Therefore, the fourth current-limiting module R... SW2 With the first current limiting module R gon After series connection, the total impedance of the variable resistor circuit can be increased, thereby reducing the current flowing through the variable resistor circuit. This is achieved by controlling the fourth current limiting module R. SW2 The specific impedance value allows for precise control of the current magnitude. Therefore, if it is determined that the current of a certain power switch is too high, the fourth current limiting module R can be used to control the current. SW2 With the first current limiting module R gon Series connection can reduce the current flowing through the variable resistor circuit, thereby reducing the current flowing into the power switch and achieving current sharing after multiple power switches are connected in parallel.

[0058] Understandably, this is achieved by setting the fourth current limiting module R. SW2 It can control the total impedance of a variable resistor circuit, so that when the total impedance of the variable resistor circuit is too low, the fourth current limiting module R is connected in series. SW2 This is done by increasing the total impedance to reduce the current flowing into the power switch.

[0059] like Figure 2 , Figure 3 and Figure 4 As shown in the embodiment of this application, the variable resistance circuit further includes a second control unit SW2 and a third control unit SW3. The second control unit SW2 and the fourth current limiting module R SW2 In series, the second control unit SW2 is configured to control the fourth current limiting module R. SW2Connection and disconnection; the third control unit SW3 connects with the second control unit SW2 and the fourth current limiting module R. SW2 In parallel, the third control unit SW3 is configured to control the second control unit SW2 and the fourth current limiting module R. SW2 Short circuit. Specifically, when the second control unit SW2 is closed, the fourth current limiting module R... SW2 With the first current limiting module R gon In series; when the second control unit SW2 is disconnected, the fourth current limiting module R SW2 With the first current limiting module R gon Disconnection occurs; at this time, the first current limiting module R... gon Second current limiting module R goff Maintaining a parallel connection; however, when the third control unit SW3 is closed, the fourth limit module is short-circuited, and current flows out of the first current limiting module R. gon Second current limiting module R goff The current flows through the third control unit SW3; while when the third control unit SW3 is disconnected, the current flows out of the first current limiting module R. gon Second current limiting module R goff The current flows through the fourth current limiting module R SW2 .

[0060] In this embodiment, it is worth noting that under normal control conditions, when the third control unit SW3 is closed, the second control unit SW2 is either open or closed, and at this time, the fourth current limiting module R... SW2 When short-circuited, current flows through the first current-limiting module R connected in parallel. gon Second current limiting module R goff The current then flows into the power switch; if the current flowing into the power switch is too large, the second control unit SW2 closes while the third control unit SW3 opens, at which point the fourth current limiting module R... SW2 With the first current limiting module R gon In series, the total impedance of the variable resistor circuit increases, and the current flowing into the open switch decreases.

[0061] It is understandable that by setting the second control unit SW2 and the third control unit SW3, the power switch can be controlled to switch between normal conditions and excessive current conditions, thereby achieving current sharing control of the power switch.

[0062] like Figure 2 and Figure 4 As shown in the embodiment of this application, the variable resistance circuit further includes a first current-limiting module and a second current-limiting module, the first current-limiting module and the third current-limiting module R sw1 The connection is such that the first current-limiting module is configured to limit the current flowing through the third current-limiting module R from the output terminal. sw1 The second current interception module and the second current limiting module Rgoff The connection is such that the second current-limiting module is configured to limit the current flowing through the second current-limiting module R at the output terminal. goff Specifically, the first current-limiting module includes a first diode D1, and the second current-limiting module includes a second diode D2. The anodes of both the first diode D1 and the second diode D2 are connected to the input terminal of the variable resistor circuit, and the cathode of the first diode D1 is connected to the third current-limiting module R. sw1 The cathode of the second diode D2 is connected to the second current limiting module R. goff Because diodes have unidirectional conduction characteristics, current can flow from the input terminal of the variable resistor circuit and through the second current limiting module R. goff and the third current limiting module R sw1 It then flows out from the output terminal, but cannot flow into the output terminal of the variable resistor circuit and then through the second current limiting module R. goff and the third current limiting module R sw1 .

[0063] In this embodiment, it is worth noting that when the power switch needs to be turned on, the control signal flows in from the input terminal of the variable resistor circuit and out from the output terminal. If the current flowing into the power switch is too small, the first control unit SW1 and the third control unit SW3 can be closed. The control signal is divided into three paths that flow through the first current-cutting module and the third current-limiting module R respectively. sw1 Second interception module and second current limiting module R goff and the first current limiting module R gon The current converges at the output terminal and flows out; if the current flowing into the power switch is too large, the second control unit SW2 is closed, and the control signal can be split into two paths that flow through the second current-cutting module and the second current-limiting module R respectively. goff and the first current limiting module R gon After the two currents merge, they flow into the fourth current limiting module R. SW2 The signal flows out from the output terminal; however, when the power switch needs to be turned off, the control signal flows from the output terminal of the variable resistor circuit to the input terminal. Affected by the current-limiting modules of the first and second current-limiting modules, and with the second control unit SW2 closed and the third control unit SW3 open, the control signal flows from the output terminal of the variable resistor circuit through the fourth current-limiting module R. SW2 and the first current limiting module R gon And flow out from the input terminal; when the third control unit SW3 is closed and the second control unit SW2 is open, the control signal flows from the output terminal of the variable resistor circuit through the first current limiting module R. gon And flow out from the input end.

[0064] It is understandable that by setting the first current-cutting module and the second current-cutting module to control the direction of the control signal of the power switch when it is turned on and off, the current magnitude of the power switch when it is turned on and off can be controlled, thereby achieving current sharing control of the power switch when it is turned on and off.

[0065] like Figure 3 As shown in the embodiments of this application, the variable resistance circuit further includes a third current-limiting module and a fourth current-limiting module, the third current-limiting module and the third current-limiting module R sw1 The connection is such that the third current limiting module is configured to limit the current flowing through the input terminal to the third current limiting module R. sw1 The fourth current-cutting module and the second current-limiting module R goff The fourth current-limiting module is configured to limit the current flowing through the second current-limiting module R from the input terminal. goff Specifically, the third current-limiting module includes a third diode D3, and the fourth current-limiting module includes a fourth diode D4. The cathodes of both the third diode D3 and the fourth diode D4 are connected to the input terminal of the variable resistor circuit, and the anode of the third diode D3 is connected to the third current-limiting module R. sw1 The anode of the fourth diode D4 is connected to the second current limiting module R. goff Because diodes have unidirectional conduction characteristics, current can flow from the output of the variable resistor circuit and through the second current-limiting module R. goff and the third current limiting module R sw1 It then flows out from the input terminal, but cannot flow in from the input terminal of the variable resistor circuit and then through the second current limiting module R. goff and the third current limiting module R sw1 .

[0066] In this embodiment, it is worth noting that when the power switch needs to be turned on, the control signal flows in from the input terminal of the variable resistor circuit and out from the output terminal. Affected by the current-limiting effects of the first and second current-limiting modules, the first current-limiting module R... gon and the fourth current limiting module R SW2 When the circuit is connected in series and the current flowing into the power switch is too small, the second control unit SW2 is disconnected and the third control unit SW3 is closed, and the control signal flows through the first current limiting module R. gon And flow out from the output terminal; in the first current limiting module R gon When the circuit is connected and the current flowing into the power switch is too large, the second control unit SW2 is closed and the third control unit SW3 is opened, and the control signal flows through the first current limiting module R. gon Second current limiting module R goffThe signal flows out from the output terminal; when the power switch needs to be turned off, the control signal flows from the output terminal of the variable resistor circuit to the input terminal. When the current of the control signal is too large, the first control unit SW1 and the third control unit SW3 are closed, the second control unit SW2 is opened, and the control signal from the output terminal of the variable resistor circuit is split into three paths, each flowing through the first current limiting module R. gon Second current limiting module R goff and the fourth current-cutting module and the third current-limiting module R sw1 The current flows out after converging with the third current-limiting module at the input terminal; when the current of the control signal is too small, the first control unit SW1 and the third control unit SW3 are disconnected, the second control unit SW2 is closed, and the control signal flows from the output terminal of the variable resistor circuit through the fourth current-limiting module R. SW2 It is then split into two streams, each flowing through the first current limiting module R. gon and the second current limiting module R goff And the third intercept module, and flows out from the input.

[0067] It is understandable that by setting the third and fourth current-cutting modules to control the direction of the control signal of the power switch when it is turned on and off, the current magnitude of the power switch when it is turned on and off can be controlled, thereby achieving current sharing control of the power switch when it is turned on and off.

[0068] like Figure 4 As shown in the embodiment of this application, the variable resistance circuit further includes a first voltage regulator module L1, a second voltage regulator module L2, a third voltage regulator module L3, a fourth voltage regulator module L4, and a fifth voltage regulator module L5. The first voltage regulator module L1 and the third current limiting module R sw1 In series, the first voltage regulator module L1 is configured to stably flow through the third current limiting module R. sw1 The current; the second voltage regulator module L2 and the first current limiting module R gon The connection is made so that the second voltage regulator module L2 is configured to stably flow through the first current limiting module R. gon The current; the third voltage regulator module L3 and the second current limiting module R goff The third voltage regulator module L3 is configured to stably flow through the second current limiting module R. goff The current; the fourth voltage regulator module L4 and the fourth current limiting module R SW2 The fourth voltage regulator module L4 is configured to provide a stable flow through the fourth current limiting module R. SW2The fifth voltage regulator module L5 is connected to the third control unit SW3 and is configured to stabilize the current flowing through the third control unit SW3. Specifically, the first voltage regulator module L1 includes a first inductor, the second voltage regulator module L2 includes a second inductor, the third voltage regulator module L3 includes a third inductor, the fourth voltage regulator module L4 includes a fourth inductor, and the fifth voltage regulator module L5 includes a fifth inductor. Inductors can convert electrical energy into magnetic energy for storage and release energy when the current changes, thereby maintaining current stability.

[0069] It is understandable that the inductor in the circuit can store electrical energy when the circuit is powered on and release electrical energy when the power switch needs to be turned on, thereby speeding up the turn-on speed of the power switch. At the same time, it can prevent sudden current changes when the power switch needs to be turned off, thus achieving current sharing control of the power switch when it is turned on and off.

[0070] like Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown in this embodiment, the power conversion circuit further includes a processor unit connected to a first control unit SW1, a second control unit SW2, and a third control unit SW3. The processor unit is configured to control the closing or opening of the first control unit SW1, the second control unit SW2, or the third control unit SW3 based on the maximum current value, the minimum current value, and the average current value flowing through the power switches. Specifically, the processor unit acquires the current value of each power switch and calculates the maximum current value, the minimum current value, and the average current value based on the obtained current value. It determines the deviation between the maximum and minimum current values ​​based on the average current value and can determine whether current control of the power switches is required based on the deviation value. If control is required, it locates the corresponding power switch based on the maximum and minimum current values. Furthermore, it controls the closing or opening of the first control unit SW1, the second control unit SW2, or the third control unit SW3 in the variable resistor circuit connected to the power switches, thereby reducing or increasing the current flowing through the power switches and achieving current sharing control of the power switches.

[0071] In this embodiment, the processor unit includes any one of a digital signal processor, a central processing unit, a switch driver chip, and an industrial controller. The processor unit can detect multiple current values ​​and output signals, enabling the closing and closing control of the first control unit SW1, the second control unit SW2, and the third control unit SW3.

[0072] It is understandable that the processor unit can identify the power switch with excessive or insufficient current among multiple power switches, and control the control unit of the variable resistor circuit to open or close based on the deviation between the current value and the average current value, thereby achieving current sharing control of the power switches.

[0073] like Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown in this embodiment, the power conversion circuit further includes a data acquisition unit connected to a power switch. The data acquisition unit is configured to acquire the current flowing through the power switch. Specifically, the data acquisition unit is connected to each power switch to acquire the current flowing into the power switch and sends the acquired current value to the processor unit. The data acquisition unit may include any one of a shunt, a Hall sensor, a Rogowski coil, a current transformer, and a fluxgate sensor.

[0074] like Figure 5 As shown in the embodiments of this application, the power switches include multiple groups, such as a first switch group (Q1_1, Q1_2-Q1_N), a second switch group (Q2_1, Q2_2-Q2_N), a third switch group (Q3_1, Q3_2-Q3_N), and a fourth switch group (Q4_1, Q4_2-Q4_N); each switch group includes N power switches, and the N power switches are connected in parallel. The following embodiment uses the first switch group as an example. The acquisition unit acquires the current of the N power switches and forms a current dataset, which is then transmitted to the processor unit; wherein, the samples of the current dataset can be represented as:

[0075] I = {I c1, I c2 ,…,I cN};

[0076] In the formula, I represents the current dataset obtained from the acquisition. c1 This is the collector current of power switch Q1_1, and so on, I c2 I is the collector current of power switch Q1_2. cN This is the collector current of the power switch Q1_N.

[0077] The processor unit processes the current dataset and selects the maximum current value I. max Minimum current value I min and average current value I avg The system precisely locates power switches that are experiencing excessive or insufficient current based on the current value. By controlling the first control unit SW1, the second control unit SW2, and the third control unit SW3 to turn on or off, the total impedance of the variable resistor circuit is changed. When the current flowing into the power switch is too low, the first control unit SW1 is closed, causing the third current limiting module R to... sw1 With the first current limiting module R goff Second current limiting module R gonWhen connected in parallel, the driving impedance of the power switch decreases, causing the current to turn on earlier and increasing the peak current during the turn-on process. At this point, the current of the power switch with excessive current will decrease. It is conceivable that the third current-limiting module R... sw1 The actual resistance value and the second current limiting module R gon Proportional relationship:

[0078] SR sw1 =k1*SR gon ;

[0079] In the formula, SR sw1 For the third current limiting module R sw1 The resistance value, k1 is the proportionality constant, and 0.9≤k1≤0.95, SR gon For the second current limiting module R gon The resistance value.

[0080] Similarly, during the shutdown process, for power switches with excessive current, the second control unit SW2 will be closed, the third control unit SW3 will be opened, and the fourth current limiting module R will be closed. sw2 Increasing the power switch drive turn-off impedance will reduce the current flowing into the power switch; it is conceivable that the fourth current limiting module R... sw2 The actual resistance value and the first current limiting module R goff Proportional relationship:

[0081] SR sw2 =k2*SR goff ;

[0082] In the formula, SR sw2 For the fourth current limiting module R sw2 The resistance value, k2 is the proportionality constant, and 0.5≤k2≤1, SR goff For the first current limiting module R goff The resistance value.

[0083] Understandably, the current flowing into each power switch is collected by the acquisition unit, and the obtained current value is sent to the processor unit. The processor unit controls the corresponding control unit according to the current value. By adjusting the closing and opening of the control unit, the total impedance of the variable resistance circuit is adjusted, thereby realizing the current sharing control of the power switches.

[0084] like Figure 5 and Figure 6As shown in this embodiment, the acquisition unit includes a current acquisition circuit, which includes an operational amplifier and peripheral circuitry connected to the operational amplifier. The operational amplifier has a negative input terminal configured to receive a reference voltage. Specifically, the peripheral circuitry includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first capacitor C1, and a second capacitor C2. The operational amplifier has a positive input terminal, a negative input terminal, and an amplification output terminal. The first resistor R1 and the second resistor R2 are respectively connected to the negative input terminal. The other end of the first resistor R1 is connected to the reference voltage. The fourth resistor R4 is connected to the positive input terminal. The third resistor R3 is connected between the second resistor R2 and the fourth resistor R4. The fifth resistor R5 is connected between the positive input terminal and the amplification output terminal. The first capacitor C1 is connected in parallel with the fifth resistor R5. The sixth resistor R6 is connected to the amplification output terminal. The second capacitor C2 is connected to the sixth resistor R6. It is worth noting that the first resistor R1 and the second resistor R2 form a voltage divider network. The first resistor R1 is connected to the reference voltage, which can ensure the stability of the reference point for current detection and avoid zero-point drift. The third resistor R3 is connected between the second resistor R2 and the fourth resistor R4 to form a common-mode rejection path, reducing the influence of environmental noise. The fourth resistor R4 is set at the positive input terminal of the operational amplifier and is compared with the reference voltage at the negative input terminal to realize current sampling. The fifth resistor R5 and the first capacitor C1 are connected in parallel to form a feedback network, which can realize the setting of the amplification factor. At the same time, the first capacitor C1 can also suppress high-frequency noise. The sixth resistor R6 and the second capacitor C2 are set at the output terminal, which can form a low-pass filter to filter out high-frequency interference and improve the output signal quality.

[0085] Understandably, by setting up a current acquisition circuit, after acquiring the current of the power switch, amplification and filtering can not only accurately obtain the current value of the power switch, but also improve the quality of the signal output.

[0086] like Figure 5As shown in this embodiment, the power switch includes a transistor with an input terminal and a control terminal. The driving unit is connected to the control terminal, and the acquisition unit is connected to the input terminal. Specifically, the transistor includes an IGBT (Insulated Gate Bipolar Transistor, a power semiconductor device). The transistor has an input terminal, a control terminal, and an output terminal. The input terminal of the transistor is the emitter of the IGBT, the output terminal is the collector of the IGBT, and the control terminal is the gate of the IGBT. The conduction and turn-off states of the IGBT are controlled by applying a voltage to the gate. When there is a sufficient positive voltage between the gate and the emitter, the IGBT is turned on; when the gate voltage is lower than a certain threshold, the IGBT is turned off. When multiple IGBTs are connected in parallel, the total impedance of the variable resistor circuit needs to be controlled to maintain the voltage of each input IGBT synchronously, thereby enabling multiple IGBTs to conduct simultaneously.

[0087] It is understandable that when multiple IGBTs are connected in parallel, the gate voltage of the IGBTs can be controlled within a suitable range by adjusting the total impedance of the variable resistor circuit, thereby enabling the multiple parallel IGBTs to be turned on and off simultaneously.

[0088] like Figure 7 As shown in the embodiment of this application, the impedance adjustment circuit includes a variable resistor circuit, and the variable resistor circuit includes a sliding rheostat R. sw Specifically, the sliding rheostat R sw A typical resistor consists of a resistive element (such as a carbon film or wire-wound resistor), a movable slider, and fixed terminals. The resistive element is usually wound on an insulating shaft, and the slider slides along the shaft. As the slider moves along the resistive element, it changes the effective length of contact with the element, thus adjusting the resistance value connected in the circuit. The longer the contact length, the greater the resistance; conversely, the shorter the contact length, the smaller the resistance. According to Ohm's law (V=IR), with a constant voltage, the current can be controlled by changing the resistance. Increasing the resistance decreases the current; decreasing the resistance increases the current.

[0089] It is worth noting that the variable resistor circuit also includes a digital potentiometer or an analog adjustable resistor. The processor unit can send a corresponding drive signal to the digital potentiometer or analog adjustable resistor according to the magnitude of the current flowing into the power switch. The digital potentiometer or analog adjustable resistor adjusts the corresponding resistance value according to the drive signal, thereby keeping the magnitude of the current flowing into the power switch consistent and realizing current sharing control of the power switch.

[0090] It is understandable that by adjusting the total impedance through a variable resistor circuit, the input current of the power switch can be controlled, thereby achieving current sharing control after multiple power switches are connected in parallel.

[0091] In summary, the power conversion circuit provided in this application embodiment, by setting a first current limiting module R gon Second current limiting module R goff This achieves control over the current flowing into the power switches, enabling current sharing when multiple power switches are connected in parallel; this is achieved by setting a third current-limiting module R. sw1 When the current flowing into the power switch is too small, a third current limiting module R is connected in parallel. sw1 The method of reducing the total impedance increases the current flowing into the power switch; by setting the first control unit SW1, when the current flowing into the power switch is too small, the third current limiting module R is activated by closing the first control unit SW1. sw1 With the first current limiting module R gon Second current limiting module R goff Parallel connection reduces the impedance of the variable resistor circuit and increases the current flowing into the power switch; by setting a fourth current limiting module R SW2 When the current flowing into the power switch is too large, the fourth current limiting module R is connected in series. SW2 The system employs several methods to control power switch performance. These include: increasing the total impedance to reduce the current flowing into the power switch; controlling the switching between normal and excessive current conditions by setting a second control unit SW2 and a third control unit SW3; controlling the direction of the control signal flow during power switch on / off by setting a first and second current-cutting modules, thereby controlling the current magnitude during power switch on / off; storing electrical energy upon power-up and releasing it when the power switch needs to be turned on, thus accelerating the power switch's on-time and preventing sudden current changes when the power switch needs to be turned off; and using a processor unit to identify the power switch with excessive or insufficient current among multiple power switch current values ​​and controlling the control unit of the variable resistor circuit to disconnect based on the deviation between the current value and the average current value. The system controls the opening and closing of the power switches. The current flowing into each power switch is acquired by the acquisition unit, and the acquired current value is sent to the processor unit. The processor unit controls the corresponding control unit based on the current value. By adjusting the opening and closing of the control unit, the total impedance of the variable resistor circuit is adjusted. By setting up a current acquisition circuit, after acquiring the current from the power switches, the current value is accurately obtained through amplification and filtering, improving the quality of the signal output. In the case of multiple IGBTs connected in parallel, the gate voltage of the IGBTs is controlled within a suitable range by adjusting the total impedance of the variable resistor circuit, allowing multiple parallel IGBTs to be turned on and off simultaneously. Adjusting the total impedance through the variable resistor circuit controls the input current of the power switches, thereby achieving current sharing control after multiple power switches are connected in parallel.

[0092] like Figure 8As shown, this application embodiment also provides a current sharing control method for a power conversion circuit, applied to the power conversion circuit provided in any of the above embodiments; the method includes:

[0093] S1: Acquire current signals from multiple power switches.

[0094] Specifically, the current flowing into each power switch is acquired through a data acquisition unit connected to each power switch. The data acquisition unit can be any one of a shunt, Hall effect sensor, Rogowski coil, current transformer, or fluxgate sensor.

[0095] S2: Obtain the first current value and the second current value based on the current signal.

[0096] Specifically, the first current value includes the maximum current value, and the second current value includes the minimum current value. The acquisition unit sends the acquired multiple current values ​​to the processor unit, which then identifies the maximum and minimum current values ​​from among the multiple current values ​​and determines the power switch corresponding to each value.

[0097] S3: Adjust the impedance of the corresponding drive unit based on the first current value to reduce the current signal flowing through the power switch.

[0098] Specifically, when it is determined that the current of the power switch is too high, the processor unit sends a signal to the drive unit connected to the power switch to increase the impedance. The impedance adjustment circuit increases the total impedance according to the signal, thereby reducing the current flowing into the power switch and realizing current sharing among multiple power switches connected in parallel.

[0099] S4: Adjust the impedance of the corresponding drive unit based on the second current value to increase the current signal flowing through the power switch.

[0100] Specifically, when it is determined that the current of the power switch is too low, the processor unit sends a signal to the drive unit connected to the power switch to reduce the impedance. The impedance adjustment circuit reduces the total impedance according to the signal, thereby increasing the current flowing into the power switch and realizing current sharing among multiple power switches connected in parallel.

[0101] According to the above execution steps, the current value of the power switch is periodically collected, and the first control unit SW1, the second control unit SW2 and the third control unit SW3 are turned on or off according to the maximum current value, the minimum current value and the average current value, thereby realizing current sharing control of multiple parallel power switches.

[0102] In summary, the current sharing control method for the power conversion circuit provided in this application collects the current of multiple power switches connected in parallel, determines the power switches corresponding to the maximum and minimum current values ​​based on the multiple currents, and increases or decreases the current flowing into the power switches by adjusting the total impedance of the circuit accordingly. This achieves current sharing control of multiple power switches connected in parallel, thereby improving the reliability of the circuit.

[0103] This application also provides an electronic device, including a power conversion circuit as provided in any of the above embodiments. The operation process and beneficial effects of this power conversion circuit have been described in detail in the above embodiments, and will not be repeated here.

[0104] The solutions provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions in the embodiments of this application.

Claims

1. A power conversion circuit, characterized in that, include: A switching module, comprising multiple power switches connected in parallel and multiple drive units, wherein each drive unit is connected to a power switch in a one-to-one correspondence. The drive unit includes an impedance adjustment circuit configured to adjust the impedance of the drive unit to which each of the power switches is connected, based on the current of the plurality of power switches.

2. The power conversion circuit as described in claim 1, characterized in that, The impedance adjustment circuit includes a variable resistance circuit, which has an input terminal and an output terminal. The variable resistance circuit includes a first current limiting module and a second current limiting module, which are located between the input terminal and the output terminal.

3. The power conversion circuit as described in claim 2, characterized in that, The first current limiting module and the second current limiting module are connected in parallel. The variable resistor circuit also includes a third current limiting module, which is connected in parallel with the first current limiting module.

4. The power conversion circuit as described in claim 3, characterized in that, The variable resistance circuit further includes a first control unit, which is connected in series with the third current limiting module. The first control unit is configured to control the connection and disconnection of the third current limiting module.

5. The power conversion circuit as described in claim 4, characterized in that, The variable resistance circuit further includes a fourth current limiting module, which is connected in series with the first current limiting module.

6. The power conversion circuit as described in claim 5, characterized in that, The variable resistance circuit further includes a second control unit and a third control unit. The second control unit is connected in series with the fourth current limiting module. The second control unit is configured to control the connection and disconnection of the fourth current limiting module. The third control unit is connected in parallel with the second control unit and the fourth current limiting module, and the third control unit is configured to control the second control unit and the fourth current limiting module to short-circuit.

7. The power conversion circuit as described in claim 6, characterized in that, The variable resistance circuit further includes a first current-limiting module and a second current-limiting module. The first current-limiting module is connected to the third current-limiting module and is configured to limit the current flowing through the third current-limiting module at the output terminal. The second current-limiting module is connected to the second current-limiting module and is configured to limit the current flowing through the second current-limiting module at the output terminal.

8. The power conversion circuit as described in claim 6, characterized in that, The variable resistance circuit further includes a third current-limiting module and a fourth current-limiting module. The third current-limiting module is connected to the third current-limiting module and is configured to limit the current flowing through the input terminal. The fourth current-limiting module is connected to the second current-limiting module and is configured to limit the current flowing through the input terminal.

9. The power conversion circuit as described in claim 7 or 8, characterized in that, The variable resistance circuit further includes a first voltage regulator module, a second voltage regulator module, a third voltage regulator module, a fourth voltage regulator module, and a fifth voltage regulator module. The first voltage regulator module is connected in series with the third current limiting module, and the first voltage regulator module is configured to stabilize the current flowing through the third current limiting module. The second voltage regulator module is connected to the first current limiting module, and the second voltage regulator module is configured to stabilize the current flowing through the first current limiting module; The third voltage regulator module is connected to the second current limiting module, and the third voltage regulator module is configured to stabilize the current flowing through the second current limiting module; The fourth voltage regulator module is connected to the fourth current limiting module, and the fourth voltage regulator module is configured to stabilize the current flowing through the fourth current limiting module; The fifth voltage regulator module is connected to the third control unit, and the fifth voltage regulator module is configured to stabilize the current flowing through the third control unit.

10. The power conversion circuit as described in claim 6, characterized in that, The power conversion circuit further includes a processor unit connected to the first control unit, the second control unit, and the third control unit. The processor unit is configured to control the closing or opening of the first control unit, the second control unit, or the third control unit based on the maximum current value, the minimum current value, and the average current value flowing through the power switch.

11. The power conversion circuit as described in claim 1, characterized in that, The power conversion circuit further includes a data acquisition unit connected to the power switch, and the data acquisition unit is configured to acquire the current flowing through the power switch.

12. The power conversion circuit as described in claim 11, characterized in that, The acquisition unit includes a current acquisition circuit, which includes an operational amplifier and peripheral circuitry, with the peripheral circuitry connected to the operational amplifier. The operational amplifier has a negative input terminal, which is configured to receive a reference voltage.

13. The power conversion circuit as described in claim 11, characterized in that, The power switch includes a transistor, which has an input terminal and a control terminal. The driving unit is connected to the control terminal, and the acquisition unit is connected to the input terminal.

14. The power conversion circuit as described in claim 1, characterized in that, The impedance adjustment circuit includes a variable resistor circuit, which in turn includes a sliding rheostat.

15. A current sharing control method for a power conversion circuit, characterized in that, Applied to the power conversion circuit as described in any one of claims 1-14; the method includes: Acquire current signals from multiple power switches; The first current value and the second current value are obtained based on the current signal; The impedance of the corresponding drive unit is adjusted based on the first current value to reduce the current signal flowing through the power switch; The impedance of the corresponding drive unit is adjusted based on the second current value to increase the current signal flowing through the power switch.

16. An electronic device, characterized in that, Includes the power conversion circuit as described in any one of claims 1-14.

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