Power device, power conversion apparatus, and control method for power conversion apparatus

Abstract

The application provides a power device, a power conversion device and a control method of the power conversion device, and relates to the technical field of power electronics. The power device comprises a gate and a first light driving electrode. The gate is used for turning on the power device. In the process of turning on the power device, the first light driving electrode is used for receiving a first light signal to increase the current flowing through the power device when the power device is turned on. By using the application, the current flowing through the power device can be increased, and the performance of the power device is improved.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a power device, a power conversion device, and a control method for the power conversion device. Background Technology

[0002] Power devices are electronic components used to control and convert high-power electrical energy. Their main function is to switch, amplify, and regulate power. Because power devices can withstand higher voltages, currents, and power, they are key components in power electronic systems and are widely used in power supplies, motor drives, lighting, and industrial automation. Therefore, how to improve the performance of power devices and reduce chip losses is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0003] This application provides a power device, a power conversion device, and a control method for the power conversion device, which can control the power device to turn on and off through optical signals and improve the current carrying capacity of the power device.

[0004] In a first aspect, this application provides a power device, which may include a gate and a first optical driving electrode. The gate can be used to turn on the power device, and during the turn-on process of the power device, the first optical driving electrode can be used to receive a first optical signal to increase the current flowing through the power device when it is turned on. The power device may be an Insulated Gate Bipolar Transistor (IGBT), which, according to its channel type, can be divided into N-channel IGBTs (N-IGBTs) and P-channel IGBTs (P-IGBTs).

[0005] It should be understood that during the IGBT's conduction process, a current flows through the power device. At this time, the first optical drive electrode of the IGBT receives the first optical signal, which can increase the carrier concentration in the drift region within the IGBT. According to the conductivity modulation effect, the increased carrier concentration in the drift region will increase the conductivity and decrease the resistivity of the drift region, thereby increasing the current flowing through the power device when it is turned on, improving the IGBT's current-carrying capacity, and enhancing the performance of the power device.

[0006] In one feasible implementation, the power device may further include an emitter. A gate may be used to receive a turn-on voltage to increase the voltage between the gate and emitter, thereby turning on the power device; or, to decrease the voltage between the gate and emitter, thereby turning on the power device.

[0007] It should be understood that for N-IGBTs, the turn-on voltage received by the gate can increase the voltage between the gate and emitter. The N-IGBT starts conducting when this voltage is greater than or equal to its threshold voltage (Vg(th)). For P-IGBTs, the turn-on voltage received by the gate can decrease the voltage between the gate and emitter. The P-IGBT starts conducting when this voltage is less than or equal to its Vg(th).

[0008] In one feasible implementation, the power device may further include a collector, and when the voltage between the gate and the emitter is greater than or equal to a first target voltage, the first optical drive electrode may be used to receive a first optical signal to increase the current flowing from the collector to the emitter when the power device is turned on.

[0009] It should be understood that for an N-IGBT, the first target voltage can be Vg(th) of the N-IGBT. In other words, the first optical drive electrode can receive the first optical signal when the N-IGBT starts to conduct, which can increase the concentration of free carriers in the N-type drift region within the N-IGBT, thereby increasing the conductivity of the N-type drift region, reducing the resistance of the N-type drift region, and thus increasing the current flowing from the collector to the emitter when the power device is turned on, improving the performance of the power device. Optionally, the first target voltage can be the Miller plateau voltage of the N-IGBT (which can be denoted as Vgs_miller). In other words, the first optical drive electrode can receive the first optical signal when the voltage between the gate and emitter of the N-IGBT is greater than or equal to Vgs_miller, which can increase the concentration of free carriers in the N-type drift region within the N-IGBT, increasing the current flowing from the collector to the emitter when the power device is turned on. Furthermore, compared to receiving the first optical signal when the N-IGBT starts to conduct, this avoids wasting the first optical signal.

[0010] In one feasible implementation, the power device may further include a collector, and when the voltage between the gate and the emitter is less than or equal to a first target voltage, the first optical drive electrode may be used to receive a first optical signal to increase the current flowing from the emitter to the collector when the power device is turned on.

[0011] It should be understood that for a P-IGBT, the first target voltage can be Vg(th) of the P-IGBT. In other words, the first optical drive electrode can receive the first optical signal when the P-IGBT starts to conduct, which can increase the concentration of free carriers in the P-type drift region of the P-IGBT, thereby increasing the conductivity of the P-type drift region, reducing the resistance of the P-type drift region, and thus increasing the current flowing from the emitter to the collector when the power device is turned on, improving the performance of the power device. Optionally, the first target voltage can be Vgs_miller of the P-IGBT. In other words, the first optical drive electrode can receive the first optical signal when the voltage between the gate and emitter of the P-IGBT is less than or equal to Vgs_miller, which can increase the concentration of free carriers in the P-type drift region of the P-IGBT, increasing the current flowing from the emitter to the collector when the power device is turned on. Furthermore, compared with receiving the first optical signal when the P-IGBT starts to conduct, the waste of the first optical signal can be avoided.

[0012] In one feasible implementation, when the first optical drive electrode stops receiving the first optical signal, the gate can also be used to receive a turn-off voltage to turn off the power device.

[0013] It should be understood that receiving the first optical signal at the first optical drive electrode can increase the concentration of charge carriers in the drift region of the IGBT, thereby increasing the conductivity of the drift region and reducing its resistance. Therefore, when turning off the IGBT, the reception of the first optical signal can be stopped first, and then the IGBT can be turned off. This can prevent the first optical signal from hindering the IGBT's turn-off, and can also avoid signal confusion, data errors, or abnormal equipment conditions.

[0014] In one feasible implementation, the power device may further include a diode, which includes an anode, a cathode, and a second optical drive. When the gate receives a turn-off voltage and the diode current flows from the anode to the cathode, the second optical drive can be used to receive a second optical signal to improve the diode's current-carrying capacity. Here, the diode can be connected in anti-parallel with the IGBT, so that the current flowing through the IGBT is transferred to the anti-parallel diode to maintain continuous current flow and prevent reverse voltage damage to the IGBT. Specifically, the emitter of the N-IGBT can be connected to the anode of the diode, and the collector of the N-IGBT can be connected to the cathode of the diode; the emitter of the P-IGBT can be connected to the cathode of the diode, and the collector of the P-IGBT can be connected to the anode of the diode.

[0015] It should be understood that when the gate receives the turn-off voltage, the IGBT begins to turn off. At this time, the current flowing through the IGBT will be discharged through the diode. At this time, the second optical drive electrode of the diode can receive the second optical signal, which increases the number of electron-hole pairs in the P+ region and N-type drift region inside the diode, increases the carrier concentration in the P+ region and N-type drift region, thereby increasing the conductivity and decreasing the resistivity of the diode, and improving the current carrying capacity of the diode.

[0016] Secondly, this application provides a power conversion device, which may include a controller, a power device, and an optical signal generating device. The optical signal generating device can be used to generate a first optical signal and transmit the first optical signal to the power device. The power device includes a gate and a first optical driving electrode. The controller can be used to control the gate to turn on the power device. Then, during the power device's turn-on process, the controller can be used to control the optical signal generating device to transmit the first optical signal to the optical driving electrode to increase the current flowing through the power device when it is turned on.

[0017] It should be understood that during the IGBT's conduction process, a current flows through the IGBT. At this time, the controller controls the optical signal generation device to transmit the first optical signal to the first optical driving electrode of the IGBT, which can increase the carrier concentration in the drift region of the IGBT, thereby increasing the conductivity and decreasing the resistivity of the drift region, thus improving the IGBT's current-carrying capacity and increasing the current flowing through the IGBT.

[0018] In one feasible implementation, the power device may further include an emitter. The controller can be used to apply a turn-on voltage to the gate to increase the voltage between the gate and emitter, thereby turning on the power device; or, to decrease the voltage between the gate and emitter, thereby turning on the power device. It should be understood that by applying a turn-on voltage to the gate, the opening of the internal conduction channel of the IGBT can be controlled, thereby controlling the IGBT's conduction state and enabling current flow between the collector and emitter of the IGBT.

[0019] In one feasible implementation, the power device may further include a collector. When the voltage between the gate and emitter is greater than or equal to a first target voltage, the controller can be used to control the optical signal generating device to transmit a first optical signal to the first optical driving electrode, thereby increasing the current flowing from the collector to the emitter when the power device is turned on. It should be understood that for an N-IGBT, when the Vge of the N-IGBT is greater than or equal to the first target voltage, controlling the optical signal generating device to transmit the first optical signal to the first optical driving electrode can increase the concentration of free carriers in the N-type drift region within the N-IGBT, thereby increasing the conductivity of the N-type drift region, reducing the resistance of the N-type drift region, further increasing the current flowing from the collector to the emitter, and improving the performance of the power device.

[0020] In one feasible implementation, the power device may further include a collector. When the voltage between the gate and emitter is less than or equal to a first target voltage, the controller can be used to control the optical signal generating device to transmit a first optical signal to the first optical driving electrode, thereby increasing the current flowing from the emitter to the collector when the power device is turned on. It should be understood that for a P-IGBT, when the Vge of the P-IGBT is less than or equal to the first target voltage, controlling the optical signal generating device to transmit the first optical signal to the first optical driving electrode can increase the concentration of free carriers in the P-type drift region of the P-IGBT, thereby increasing the conductivity of the P-type drift region, reducing the resistance of the P-type drift region, further increasing the current flowing from the collector to the emitter, and improving the performance of the power device.

[0021] In one feasible implementation, the controller can also be used to control the optical signal generating device to stop transmitting the first optical signal to the first optical driving electrode. Furthermore, when the optical signal generating device stops transmitting the first optical signal to the first optical driving electrode, the controller can also be used to control the gate to receive a turn-off voltage to turn off the power device.

[0022] It should be understood that when turning off the IGBT, the optical signal generating device can be controlled to stop transmitting the first optical signal to the first optical drive electrode first, and then the gate can be controlled to turn off the IGBT. This can avoid the first optical signal from hindering the IGBT's turn-off, and can also avoid signal confusion, data errors or abnormal equipment status.

[0023] In one feasible implementation, the power device may further include a diode, which may include an anode, a cathode, and a second optical drive electrode. When the gate receives a turn-off voltage and the diode current flows from the anode to the cathode, the controller can be used to control the optical signal generating device to transmit a second optical signal to the second optical drive electrode to improve the diode's current carrying capacity.

[0024] It should be understood that when the gate receives the turn-off voltage, the IGBT begins to turn off. At this time, the current flowing through the IGBT will be discharged through the diode. At this time, the controller can control the optical signal generating device to transmit the second optical signal to the second optical driving electrode, which can increase the number of electron-hole pairs in the P+ region and N-type drift region inside the diode, increase the carrier concentration in the P+ region and N-type drift region inside the diode, thereby increasing the conductivity and decreasing the resistivity of the diode, and improving the current carrying capacity of the diode.

[0025] Thirdly, this application provides a control method for a power conversion device. The power conversion device may include a controller, a power device, and an optical signal generating device. The optical signal generating device can be used to generate a first optical signal and transmit the first optical signal to the power device. The power device may include a gate and a first optical driving electrode. The method includes: controlling the gate to turn on the power device; during the process of the power device being turned on, controlling the optical signal generating device to transmit the first optical signal to the first optical driving electrode to increase the current flowing through the power device when the power device is turned on.

[0026] It should be understood that during the IGBT conduction process, transmitting the first optical signal to the first optical driving electrode of the IGBT by controlling the optical signal generation device can increase the carrier concentration in the drift region of the IGBT, thereby increasing the current flowing through the power device and thus improving the performance of the power device.

[0027] In one feasible implementation, the power device further includes an emitter. The control gate to turn on the power device includes: controlling the gate to receive a conduction voltage to increase the voltage between the gate and the emitter, thereby turning on the power device; or, decreasing the voltage between the gate and the emitter, thereby turning on the power device. IGBTs can be classified into N-IGBTs and P-IGBTs according to their channel type. The working principles and structures of N-IGBTs and P-IGBTs can be found above and will not be elaborated further here. It should be understood that by applying a conduction voltage to the gate, the opening of the internal conduction channel of the IGBT can be controlled, thereby controlling the conduction state of the IGBT and enabling current flow between the collector and emitter of the IGBT.

[0028] In one feasible implementation, the power device further includes a collector. The method of controlling the optical signal generating device to transmit a first optical signal to the first optical driving electrode during the power device conduction process to increase the current flowing through the power device when the power device is turned on includes: when the voltage between the gate and the emitter is detected to be greater than or equal to a first target voltage, controlling the optical signal generating device to transmit a first optical signal to the first optical driving electrode to increase the current flowing from the collector to the emitter when the power device is turned on.

[0029] It should be understood that for N-IGBTs, when the voltage between the gate and emitter of the N-IGBT is greater than or equal to the first target voltage, transmitting the first optical signal to the first optical drive electrode by controlling the optical signal generation device can increase the carrier concentration in the N-type drift region, thereby increasing the conductivity and decreasing the resistivity of the N-type drift region, thus increasing the current flowing from the collector to the emitter and improving the performance of the power device.

[0030] In one feasible implementation, the power device further includes a collector. The method of controlling the optical signal generating device to transmit a first optical signal to the first optical driving electrode during the power device conduction process to increase the current flowing through the power device when the power device is turned on includes: when the voltage between the gate and the emitter is detected to be less than or equal to a first target voltage, controlling the optical signal generating device to transmit a first optical signal to the first optical driving electrode to increase the current flowing from the emitter to the collector when the power device is turned on.

[0031] It should be understood that for P-IGBTs, when the voltage between the gate and emitter of the P-IGBT is less than or equal to the first target voltage, the optical signal generating device can be controlled to transmit the first optical signal to the first optical driving electrode, which can increase the concentration of free carriers in the P-type drift region, thereby increasing the current flowing through the collector when the power device is turned on and improving the performance of the power device.

[0032] In one feasible implementation, the method further includes: controlling the optical signal generating device to stop transmitting the first optical signal to the first optical driving electrode; and controlling the gate to turn off the power device when the first optical driving electrode stops receiving the first optical signal.

[0033] It should be understood that when turning off the IGBT, the optical signal generating device can be controlled to stop transmitting the first optical signal to the first optical drive electrode before turning off the IGBT. This can prevent the first optical signal from hindering the IGBT's turn-off, and can also avoid signal confusion, data errors or abnormal equipment status.

[0034] In one feasible implementation, the power device further includes a diode, which includes an anode, a cathode, and a second optical driving electrode. The method further includes: when the gate receives a turn-off voltage and the current of the diode is detected flowing from the anode to the cathode, controlling the optical signal generating device to transmit a second optical signal to the second optical driving electrode to improve the current carrying capacity of the diode.

[0035] It should be understood that the diode can achieve freewheeling when the IGBT is turned off. At this time, the optical signal generating device can be controlled to transmit the second optical signal to the second optical driving electrode, which can increase the carrier concentration in the P+ region and N-type drift region of the diode, thereby improving the current carrying capacity of the diode and accelerating the discharge speed. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the architecture of a photovoltaic power generation system provided in an embodiment of this application; Figure 2a This is a circuit diagram of a power device provided in an embodiment of this application; Figure 2b This is a cross-section of the power device provided in the embodiments of this application; Figure 3This is a timing diagram illustrating the conduction of a power device provided in an embodiment of this application; Figure 4 This is a schematic diagram showing the relationship between voltage and current of a power device provided in an embodiment of this application; Figure 5a This is another circuit diagram of the power device provided in the embodiments of this application; Figure 5b This is another cross-section of the power device provided in the embodiments of this application; Figure 6 This is another timing diagram showing the power device 100 being turned on according to an embodiment of this application; Figure 7 This is another schematic diagram showing the relationship between voltage and current of the power device provided in the embodiments of this application; Figure 8a This is another circuit diagram of the diode provided in the embodiments of this application; Figure 8b This is another cross-section of the diode provided in the embodiments of this application; Figure 9 This is another timing diagram illustrating the conduction of the power device provided in the embodiments of this application; Figure 10 This is another timing diagram illustrating the conduction of the power device provided in the embodiments of this application; Figure 11 This is a schematic diagram of the power conversion device provided in an embodiment of this application; Figure 12 This is another structural schematic diagram of the power conversion device provided in the embodiments of this application; Figure 13 This is a flowchart illustrating the control method for a power conversion device provided in an embodiment of this application.

[0037] Explanation of reference numerals in the attached figures: 1. Photovoltaic string; 2. Power conversion equipment; 3. Prefabricated substation; 4. Step-up substation; 5. Power grid; 6. Energy storage battery; Power device 100; controller 200; optical signal generating device 300; First optical driving electrode 110; gate electrode 111; collector electrode 112; emitter electrode 113; Anode 210; Cathode 211; Second light-driving electrode 212. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the application. It is understood that the terminology used in this specification is for the purpose of describing specific embodiments only and is not intended to limit the application. It is understood that the terms "first," "second," etc., used in this application can be used herein to describe various information or data, but these elements are not limited by these terms. These terms are only used to distinguish the first piece of information from another piece of information.

[0039] Power devices are commonly used as switches or rectifiers in power electronics applications. Common power devices include IGBTs, bipolar junction transistors (BJTs), and metal-oxide-semiconductor field-effect transistors (MOSFETs). When used as switches, power devices can form or break circuits. Current flows through a power device when it is turned on, and it blocks current flow when it is turned off. IGBTs, being composite fully controlled voltage-driven power semiconductor devices composed of BJTs and MOSFETs, combine the advantages of high input impedance of MOSFETs and low on-state voltage drop of BJTs, and are therefore widely used in power electronics, such as in photovoltaic power generation and electric vehicles. The above are merely examples of application scenarios for the power conversion equipment provided in this application, and are not exhaustive. This application does not limit the application scenarios. The following section will focus on the photovoltaic power generation field.

[0040] See Figure 1 , Figure 1 This is a schematic diagram of the architecture of a photovoltaic power generation system provided in an embodiment of this application. (Refer to...) Figure 1 In a photovoltaic (PV) power generation system, PV string 1 directly converts solar energy into electrical energy using the photovoltaic effect. PV string 1 is typically a string group, and may include multiple PV modules connected in series. Each PV module may include multiple solar cells connected in series or parallel. Power conversion equipment 2 converts the direct current (DC) from PV string 1 into alternating current (AC), and sends the AC to a corresponding prefabricated substation 3 for voltage transformation. The prefabricated substation 3 can convert the low-voltage AC output from power conversion equipment 2 into medium-voltage AC, and then transmit the AC to a step-up substation 4 and to the power grid 5 or other loads. Optionally, the PV power generation system may also include an energy storage battery 6, and the power conversion equipment 2 can convert the DC stored in the energy storage battery 6 into AC. It should be understood that... Figure 1The schematic diagram of the photovoltaic power generation system shown is only one of many possibilities, and this application does not impose any limitations on it. Power devices are widely used in the power conversion equipment 2 to convert direct current to alternating current. However, in high-frequency switching applications, IGBTs may experience high losses due to frequent on / off cycles.

[0041] Based on this, this application provides a power conversion device that can improve the current carrying capacity of power devices and reduce the losses of power devices.

[0042] The following description, in conjunction with the accompanying drawings, introduces the specific implementation principle of the power device provided in the embodiments of this application.

[0043] In one feasible implementation, the power device may include a gate and a first optical driving electrode. The gate can be used to turn on the power device, and during the turn-on process, the first optical driving electrode can be used to receive a first optical signal to increase the current flowing through the power device when it is turned on. Where the power device includes a gate, the power device can be an IGBT, which can be classified into N-IGBT and P-IGBT according to its channel type. When an N-IGBT is turned on, the current flows from the collector to the emitter; when a P-IGBT is turned on, the current flows from the emitter to the collector. The implementation principles of N-IGBT and P-IGBT will be described below.

[0044] Example 1: See Figure 2a , Figure 2a This is a circuit diagram of a power device provided in an embodiment of this application. Figure 2a This can be a circuit diagram of an N-IGBT, which may include a gate g, a collector c, an emitter e, and a first optical drive terminal n. It should be noted that g(n) can represent both the gate g and the first optical drive terminal n. The first optical drive terminal n can receive a first optical signal. Please refer to [further details omitted]. Figure 2b , Figure 2b This is a cross-section of the power device provided in the embodiments of this application. Figure 2bThis paper introduces a planar gate N-IGBT. The N-type drift region can be a lightly doped N-type semiconductor region formed on the top surface of a P+ type substrate. The N-type drift region can be an epitaxial layer. A P-type well region can be located within the N-type drift region and contact its top surface. A heavily doped P-type region (P+ region) can be located within the P-type well region and contact its top surface. A heavily doped N-type region (N+ region) is formed within the P-type well region, contacting its corresponding heavily doped P-type region and its top surface. The carrier concentration in the heavily doped N-type region is generally higher than that in the N-type drift region, and the carrier concentration in the heavily doped P-type region is generally higher than that in the P-type well region. The N-type heavily doped region can be led out through a metal layer to produce the emitter 113, and the P+ type substrate can be led out through a metal layer to produce the collector 112. The gate 111 can be located on the N-type drift region and isolated from the emitter 113 and the internal conductive channels of the power device by an insulating layer 114. This ensures that the gate 111 can control the distribution of charge carriers in the power device, thereby achieving precise control over the power device's turn-on and turn-off. It is worth mentioning that the insulating layer 114 can be made of silicon dioxide (SiO2), which can effectively reduce the input and output capacitance of the power device and also block leakage current in the main channel, thereby improving its switching speed and operating efficiency. It should be understood that, as... Figure 2b The structure of the N-IGBT shown is only one of many feasible implementations, and the embodiments of this application do not limit the structure of the N-IGBT.

[0045] In one feasible implementation, an N-buffer zone may also be included between the N-type drift region and the P+ type substrate. The carrier concentration of the N-buffer zone is generally higher than that of the N-type drift region. It can be used to compress the electric field, alleviate the electric field concentration phenomenon, reduce the turn-off tail current, and reduce the thickness of the N-type drift region to reduce the saturation voltage drop and shorten the switching time.

[0046] It should be explicitly stated that in layers and regions prefixed with N or P, electrons or holes are the majority carriers, respectively. Furthermore, a "+" sign with N or P indicates a higher doping concentration than the unlabeled layer or region; for example, P+ can represent a heavily P-type doped region, and N+ can represent a heavily N-type doped region. A "-" sign with N or P indicates a lower doping concentration than the unlabeled layer or region.

[0047] In one feasible implementation, the gate 111 can be a split gate, such as... Figure 2bThe diagram shows split gates 111a and 111b. In other words, the gate 111 can form a dual-gate system through physical separation. The split gate has advantages such as improved channel conduction efficiency and reduced gate leakage current. It should be understood that the insulating layer 114 can be located on the top surface of the N-type drift region and wrap around the split gate. An insulating layer also exists in the region between the two split gates, that is, the region between the two split gates can be the first optical drive electrode 110, which can receive the first optical signal. It should be understood that because SiO2 has a specific refractive index, the first optical signal can pass through the insulating layer 114 and irradiate the N-type drift region, increasing the number of electron-hole pairs in the N-type drift region. As the intensity of the first optical signal increases, the concentration of free carriers in the N-type drift region increases. According to the conductivity modulation effect, the increase in the concentration of charge carriers in the N-type drift region will increase the conductivity and decrease the resistivity of the N-type drift region, thereby increasing the current carrying capacity of the N-IGBT and thus increasing the current flowing through the N-IGBT.

[0048] In one feasible implementation, the power device may further include an emitter. A gate may be used to receive a turn-on voltage to increase the voltage between the gate and emitter, thereby turning on the power device.

[0049] In specific implementations, for N-IGBTs, the N-IGBT begins to conduct when the voltage (Vge) between the gate 111 and the emitter 113 is greater than or equal to the threshold voltage (denoted as Vg(th), e.g., 0.7V) of the N-IGBT. It should be noted that those skilled in the art should understand that the voltage (Vce) between the collector and emitter of the N-IGBT being greater than or equal to the turn-on voltage of the N-IGBT is a necessary condition for the N-IGBT to conduct. In other words, the conduction of the N-IGBT mentioned in the embodiments of this application is achieved under the premise that the Vce of the N-IGBT is greater than or equal to the turn-on voltage of the N-IGBT.

[0050] See Figure 3 , Figure 3 This is a timing diagram illustrating the conduction of a power device provided in an embodiment of this application. For example... Figure 3As shown, before time t1, Vge is at a low level (e.g., -10V). At time t1, Vge of the N-IGBT gradually increases. When Vce is greater than or equal to the turn-on voltage of the N-IGBT, and Vge is greater than or equal to the Vg(th) of the N-IGBT, as at time t2, an N-type inversion layer begins to form on the surface of the P-type well region, a channel begins to appear, and a conduction path begins to form between the collector 112 and the emitter 113. Electrons from the heavily doped N-type region begin to enter the N-type drift region through the channel. As Vge increases, more electrons enter the N-type drift region from the heavily doped N-type region through the channel, causing a change in the carrier concentration within the N-type drift region. This reduces the resistance and lowers the potential within the N-type drift region. At this point, the heavily doped P-type region injects holes into the N-type drift region. These injected holes recombine with electrons, forming a current path from the collector 112 through the N-type drift region, the P-type well region, and the conductive channel to the emitter 113. This current path is the collector current, denoted as Ic. For example, at time t3, Ic begins to increase. At time t4, Vge increases to a high level (e.g., 15V), and the N-IFBT is fully turned on.

[0051] Furthermore, such as Figure 2b As shown, the power device may also include a collector 112. When the voltage between the gate 111 and the emitter 113 is greater than or equal to the first target voltage, the first optical drive electrode 110 can be used to receive the first optical signal to increase the current flowing from the collector 112 to the emitter 113 when the power device is turned on.

[0052] In a specific implementation, the first target voltage can be the threshold voltage of the N-IGBT, i.e., Vg(th). When Vge ≥ Vg(th), the first optical drive electrode 110 can receive the first optical signal. In other words, in the case of... Figure 3 At any time from t2 to t5, the first optical driving electrode 110 can receive the first optical signal. When the first optical signal illuminates the N-type drift region, the carrier concentration in the N-type drift region increases, causing the conductivity of the N-type drift region to increase and the resistivity to decrease, thereby increasing the current flowing from the collector 112 to the emitter 113 when the N-IGBT is turned on, i.e., the collector current (Ic).

[0053] See Figure 4 , Figure 4 This is a schematic diagram illustrating the relationship between voltage and current of a power device provided in an embodiment of this application. For example... Figure 4As shown, the vertical axis represents Ic, and the horizontal axis represents Vce. The solid line represents the change in Ic of the N-IGBT with the first optical drive electrode 110 (i.e., IGBT-light) when receiving the first optical signal, while the dashed line represents the change in Ic of the N-IGBT without the first optical drive electrode 110 when it is turned on. It can be seen that when Vce = V0, the Ic value of IGBT-light is greater than the Ic value of IGBT. In other words, receiving the first optical signal through the first optical drive electrode 110 can increase the current flowing through the collector of the N-IGBT when it is turned on.

[0054] It should be understood that when Vge ≥ Vg(th), that is, the first optical drive electrode 110 can be applied after Vge ≥ Vg(th) and before the gate 111 receives the turn-off voltage (e.g. Figure 3 Receiving the first optical signal at any time (from t2 to t5) can increase the concentration of charge carriers in the N-type drift region, thereby increasing the conductivity and decreasing the resistivity of the N-type drift region, and thus effectively increasing the current flowing through the N-IGBT (such as Ic).

[0055] It is worth mentioning that when Vge just begins to be greater than or equal to Vg(th) (e.g., from time t2 to t3), the current flowing through collector 112 increases from zero, and Vce is positive. Here, when the N-IGBT is connected to the DC bus, Vce can maintain the bus voltage, preventing the N-IGBT from exhibiting a fully conducting phenomenon. Furthermore, during the turn-on or turn-off process of power semiconductor devices such as IGBTs, the presence of parasitic capacitances within the power device (such as the parasitic capacitance between the gate 111 and collector 112 of the IGBT) causes Vge to remain relatively stable for a certain period. This voltage plateau is called the "Miller plateau voltage," denoted as Vgs_miller. Specifically, during the IGBT's turn-on or turn-off process, when Vce changes, the voltage of the parasitic capacitance between the gate 111 and collector 112 also changes accordingly, generating a current opposite to the current in the gate 111. This slows down the rise or fall rate of the gate 111 voltage, or even keeps it constant for a period of time, forming a waveform similar to a "plateau," such as... Figure 3The time t3 is shown. It can be seen that during the stage of Vgs_miller > Vge ≥ Vg(th), the current flowing through collector 112 begins to increase, preventing the IGBT from fully conducting. When Vge ≥ Vgs_miller, the conductive channel is fully open, Ic begins to increase, and the IGBT begins to conduct fully. In summary, during the stage of Vgs_miller > Vge ≥ Vg(th), because Ic is very small, even if receiving the first optical signal increases the carrier concentration in the N-type drift region, the effect on increasing Ic is very weak. Based on this, the first optical signal can be received after Ic begins to increase, i.e., when Vge ≥ Vgs_miller. At this time, the first target voltage can be Vgs_miller. In this way, the first optical drive electrode 110 can receive the first optical signal when the current value of Ic begins to increase, thereby improving the growth rate and magnitude of Ic, avoiding the waste of the first optical signal compared to having the first target voltage as Vg(th).

[0056] It is understandable that when the Vge of the N-IGBT is greater than or equal to the first target voltage, receiving the first optical signal through the first optical driving electrode 110 can increase the concentration of free carriers in the N-type drift region. According to the conductivity modulation effect, as the concentration of carriers increases, the conductivity of the N-type drift region can be increased, the resistance of the N-type drift region can be reduced, and the on-state voltage drop of the N-IGBT can be reduced to a certain extent, thereby increasing Ic and reducing the power loss of the N-IGBT, and improving the performance of the power device.

[0057] Example 2: See Figure 5a , Figure 5a This is another circuit diagram of the power device provided in the embodiments of this application. Figure 5a This can be a circuit diagram of a P-IGBT, which may include a gate g, a collector c, an emitter e, and a first optical drive terminal n. It should be noted that g(n) can represent the gate g and the first optical drive terminal n. The first optical drive terminal n can receive a first optical signal. See also... Figure 5b , Figure 5b This is another cross-section of the power device provided in the embodiments of this application. Figure 5bThis paper introduces a planar gate P-IGBT. The P-type drift region can be a lightly doped P-type semiconductor region formed on the top surface of an N+ type substrate. The P-type drift region can be an epitaxial layer. An N-type well region can be located within the P-type drift region and contact its top surface. A heavily doped P-type region (P+ region) can be located within the N-type well region and contact its top surface. A heavily doped N-type region (N+ region) is formed within the N-type well region, contacting the corresponding heavily doped P-type region and also contacting the top surface of the P-type drift region. The carrier concentration in the heavily doped P-type region is generally higher than that in the P-type drift region, and the carrier concentration in the heavily doped N-type region is generally higher than that in the N-type well region. The P-type heavily doped region can be led out through a metal layer to produce the emitter 113, and the N+ type substrate can be led out through a metal layer to produce the collector 112. The gate 111 can be located on the P-type drift region and is isolated from the emitter 113 and the internal conductive channels of the power device by an insulating layer 114, ensuring that the gate 111 can control the distribution of charge carriers in the power device, thereby achieving precise control over the turn-on and turn-off of the power device. It should be understood that, as Figure 5b The structure of the P-IGBT shown is only one of many feasible implementations, and the embodiments of this application do not limit the structure of the P-IGBT.

[0058] It should be explicitly stated that in layers and regions prefixed with N or P, electrons or holes are the majority carriers, respectively. Furthermore, a "+" sign with N or P indicates a higher doping concentration than the unlabeled layer or region; for example, P+ can represent a heavily P-type doped region, and N+ can represent a heavily N-type doped region. A "-" sign with N or P indicates a lower doping concentration than the unlabeled layer or region.

[0059] In one feasible implementation, a P-buffer zone may also be included between the P-type drift region and the N+ type substrate. The carrier concentration of the P-buffer zone is generally higher than that of the P-type drift region. It can be used to compress the electric field, alleviate the electric field concentration phenomenon, reduce the turn-off tail current, and reduce the thickness of the P-type drift region to reduce the saturation voltage drop and shorten the switching time.

[0060] Please see again. Figure 5bThe gate 111 may include a split gate 111a and a split gate 111b. In other words, the gate 111 can be a dual-gate system formed by physical separation. The split gate has advantages such as improved channel conduction efficiency and reduced gate leakage current. It should be understood that the insulating layer may be located on the top surface of the P-type drift region and wrap around the split gate. An insulating layer also exists in the region between the two split gates. That is, the region between the two split gates may be the first optical drive electrode 110, which can receive the first optical signal. It should be understood that the first optical signal can pass through the insulating layer 114 to irradiate the P-type drift region, increasing the concentration of free carriers in the P-type drift region, thereby increasing the conductivity and decreasing the resistivity of the P-type drift region, and thus increasing the current carrying capacity of the P-IGBT, thereby increasing the current flowing through the P-IGBT.

[0061] In one feasible implementation, the power device may further include an emitter. A gate may be used to receive a turn-on voltage to reduce the voltage between the gate and the emitter, thereby turning on the power device.

[0062] In specific implementations, for a P-IGBT, the P-IGBT begins to conduct when the voltage between the gate 111 and the emitter 113 is less than or equal to the P-IGBT's threshold voltage (e.g., -0.7V). It should be noted that those skilled in the art should understand that a voltage between the collector 112 and the emitter 113 of the P-IGBT being less than or equal to the turn-on voltage (i.e., the P-IGBT's turn-on voltage, which is negative) is a necessary condition for the P-IGBT to conduct. In other words, the conduction of the P-IGBT mentioned in the embodiments of this application is achieved under the premise that the P-IGBT's Vce is less than or equal to the P-IGBT's turn-on voltage.

[0063] See Figure 6 , Figure 6 This is another timing diagram illustrating the conduction of the power device provided in an embodiment of this application. For example... Figure 6 As shown, before time t1, Vge is at a high level (e.g., +10V). At time t1, Vge of the P-IGBT gradually decreases. When Vce is less than or equal to the turn-on voltage of the P-IGBT, and Vge is less than or equal to the threshold voltage of the P-IGBT (e.g., ...), ... Figure 6 When Vg(th) is shown, such as at time t2, a P-type inversion layer begins to form on the surface of the N-type well region, and a channel begins to appear, forming a conductive path between the collector 112 and the emitter 113. As Vge decreases, a current path is formed from the emitter 113 to the collector 112, which is the collector current, denoted as Ic. At time t3, Ic begins to increase, and at time t4, Vge decreases to a low level (e.g., -15V), and the P-IFBT is fully turned on.

[0064] Furthermore, such as Figure 5bAs shown, the power device also includes a collector 112. When the voltage between the gate 111 and the emitter 113 is less than or equal to the second target voltage, the first optical drive electrode 110 can be used to receive the first optical signal to increase the current flowing from the emitter 113 to the collector 112 when the power device is turned on.

[0065] In a specific implementation, the second target voltage can be the threshold voltage of the P-IGBT, i.e., Vg(th). When Vge ≤ Vg(th), the first optical drive electrode 110 can receive the first optical signal. In other words, in the case of... Figure 6 At any time from t2 to t5, when the first optical signal irradiates the P-type drift region, the carrier concentration in the P-type drift region increases, which increases the conductivity and decreases the resistivity of the P-type drift region, thereby increasing the current (such as Ic) flowing through the collector 112 when the P-IGBT is turned on.

[0066] See Figure 7 , Figure 7 This is another schematic diagram showing the relationship between voltage and current of the power device provided in the embodiments of this application. For example... Figure 7 As shown, the vertical axis represents Ic, and the horizontal axis represents Vce. The solid line represents the change in Ic of the N-IGBT (i.e., IGBT-light) with the first optical drive electrode 110 when receiving the first optical signal, and the dashed line represents the change in Ic of the N-IGBT (i.e., IGBT) without the first optical drive electrode 110 when it is turned on. It can be seen that when Vce = V0', the Ic value of IGBT-light is greater than the Ic value of IGBT. In other words, receiving the first optical signal through the first optical drive electrode 110 can increase Ic.

[0067] It should be understood that, when Vge ≤ Vg(th), the first optical drive electrode 110 can be installed after Vge ≤ Vg(th) and before the gate 111 receives the turn-off voltage (e.g., Figure 6 Receiving the first optical signal at any time (from t2 to t5) can increase the concentration of charge carriers in the N-type drift region, thereby increasing the conductivity and decreasing the resistivity of the P-type drift region, and thus effectively increasing the current (i.e., Ic) flowing through the P-IGBT.

[0068] It is worth mentioning that when Vge is initially less than or equal to Vg(th) (e.g., from time t2 to t3), the current flowing through collector 112 increases from zero, and Vce is positive. Here, when the P-IGBT is connected to the DC bus, Vce can maintain the bus voltage, preventing the P-IGBT from exhibiting full conduction. Furthermore, because the P-IGBT also experiences a "Miller plateau voltage" phenomenon during turn-on or turn-off, the first optical drive electrode 110 can receive the first optical signal after Ic begins to increase; in other words, the second target voltage can be Vgs_miller. When Vge ≤ Vgs_miller, the current value of Ic begins to increase, and the IGBT begins to conduct fully. At this time, the first optical signal can increase the growth rate and magnitude of Ic, and compared to receiving the first optical signal when Vge ≤ Vg(th), it can also reduce the waste of the first optical signal.

[0069] Understandably, when the Vge of the P-IGBT is less than or equal to the second target voltage, the first optical drive electrode 110 can receive the first optical signal, increase the concentration of free carriers in the P-type drift region, thereby increasing the conductivity of the P-type drift region, reducing the resistance of the P-type drift region, and thus increasing Ic, reducing the power loss of the P-IGBT, and improving the performance of the power device.

[0070] In one feasible implementation, when the first optical drive electrode 110 stops receiving the first optical signal, the gate 111 can also be used to receive a turn-off voltage to turn off the power device.

[0071] In practical implementation, taking N-IGBT as an example, the input of the first optical signal needs to be stopped before the IGBT gate receives the turn-off voltage. For example... Figure 4 As shown, at time t5, when the first optical signal stops transmitting, the first optical drive electrode 110 stops receiving the first optical signal. Then, at time t6, when the gate 111 of the N-IGBT receives the turn-off voltage, that is, when the turn-off voltage is applied to the gate 111 of the N-IGBT, Vge begins to decrease, and the N-IGBT begins to turn off. At time t7, Vge becomes low (e.g., -10V), and the N-IGBT is completely turned off.

[0072] Similarly, taking P-IGBT as an example, the input of the first optical signal needs to be stopped before the IGBT gate receives the turn-off voltage. Figure 6 As shown, at time t5, when the first optical signal stops transmitting, the first optical drive electrode 110 stops receiving the first optical signal. Then, when the gate 111 of the P-IGBT receives the turn-off voltage, that is, when the turn-off voltage is applied to the gate 111 of the P-IGBT, Vge begins to rise, and the P-IGBT begins to turn off. When Vge becomes high (e.g., 10V), the P-IGBT is completely turned off.

[0073] It is understandable that receiving the first optical signal at the first optical drive electrode 110 can increase the concentration of charge carriers in the drift region of the IGBT, thereby increasing the conductivity of the drift region and reducing the resistance of the drift region. Therefore, when turning off the IGBT, the reception of the first optical signal can be stopped first, and then the IGBT can be turned off. This can avoid the first optical signal from hindering the IGBT from turning off, and can also avoid signal confusion, data errors or abnormal equipment status.

[0074] Because diodes allow current to continue flowing even when power is cut off, current changes are smoother, reducing electromagnetic interference caused by sudden current changes. This improves circuit stability and reliability, making diodes widely used in power supplies, motor control, frequency converters, and switching circuits to protect inductive loads. Here, the diode acts as a freewheeling diode (FWD). In power conversion equipment, due to the presence of inductive loads, the current flowing through them cannot change abruptly. To maintain the current in the inductive load, the IGBT and the freewheeling diode can be connected in reverse parallel. The current flowing through the IGBT is then transferred to the anti-parallel FWD, maintaining continuous current flow and preventing reverse voltage damage to the IGBT. Specifically, the emitter of the N-IGBT is connected to the anode of the FWD, and the collector of the N-IGBT is connected to the cathode of the FWD; the emitter of the P-IGBT is connected to the cathode of the FWD, and the collector of the P-IGBT is connected to the anode of the FWD. When freewheeling current is connected in reverse parallel with the IGBT via a FWD, a faster current discharge rate results in a shorter reverse recovery time for the FWD, allowing the IGBT to enter the blocking state more quickly after being turned off, thus reducing energy loss during the reverse recovery process. Conversely, a slow current discharge rate leads to a longer reverse recovery current duration, resulting in additional power loss between the IGBT and the FWD. Therefore, the discharge rate can be accelerated by receiving a second optical signal at the second optical drive electrode of the FWD, as illustrated in the following embodiment.

[0075] Example 3: In one feasible implementation, the power device may further include a diode, which includes an anode, a cathode, and a second optical drive electrode. Here, the diode may be a positive-intrinsic-negative diode (PIN), a Schottky barrier diode (SBD), a hybrid PIN Schottky diode (Merged PIN Schottky, MPS), etc., and is not limited thereto.

[0076] See Figure 8a , Figure 8a This is another circuit diagram of the diode provided in an embodiment of this application. For example... Figure 8a As shown, the FWD may include an anode a, a cathode k, and a second optical driving electrode m, the second optical driving electrode m being capable of receiving a second optical signal. See also Figure 8b , Figure 8b This is another cross-section of the diode provided in this embodiment. The N-type drift region can be formed on an N+ type substrate. The N-type drift region can be a low-doped N-type semiconductor region, the thickness of which and the doping concentration are important parameters affecting FWD performance. The N-type drift region can be an epitaxial layer, and the P+ region can be located within the N-type drift region and in contact with the top surface of the N-type drift region. The P+ region can be a high-doped P-type semiconductor region. The cathode 211 can be led out from the N+ type substrate through a metal layer, and the anode 210 can be led out from the P+ region through a metal layer. In one feasible implementation, the anode 210 may include a split anode 210a and a split anode 210b, and the second light-driving electrode 212 may be located between the split anodes 210a and 210b (as shown by the area defined by the dashed lines). Thus, when the current of the FWD flows from the anode 210 to the cathode 211, the second optical signal received by the second light-driving electrode 212 can directly irradiate the P+ and N-type drift regions, increasing the number of electron-hole pairs in the P+ and N-type drift regions, i.e., increasing the carrier concentration in the P+ and N-type drift regions. According to the conductivity modulation effect, the increased carrier concentration in the P+ and N-type drift regions will increase the conductivity and decrease the resistivity of the FWD, thereby improving its current-carrying capacity.

[0077] In one feasible implementation, an N-buffer zone may be included between the N-type drift region and the N+ type substrate. The carrier concentration in the N-buffer zone is generally higher than that in the N-type drift region. This buffer zone can be used to compress the electric field, alleviate electric field concentration, reduce turn-off tail current, and also reduce the thickness of the N-type drift region to reduce saturation voltage drop and shorten switching time. It should be understood that, as Figure 8b The structure of the FWD shown is only one of many feasible implementations, and the embodiments of this application do not limit the structure of the FWD.

[0078] It is worth mentioning that, since the FWD needs to withstand different reverse voltages, the size of the P+ region may affect the FWD's withstand voltage capability. A larger P+ region can increase the uniformity of the electric field distribution and improve the device's surge reliability. Furthermore, a larger P+ region can accommodate more charge carriers, thereby improving the device's conduction capability under high current. Based on this, the size of the P+ region that the second optical signal can illuminate can be larger than the sizes of other P+ regions. This allows the P+ region directly illuminated by the second optical signal to accommodate more charge carriers and accelerates electron discharge within the P+ region upon receiving the second optical signal, further improving the current-carrying capacity. It should be understood that the sizes of the multiple P+ regions within the N-type drift region can be the same or different, or some of the multiple P+ regions may have the same size, while the sizes of the remaining P+ regions may differ. This application does not impose such limitations.

[0079] In a specific implementation, when the gate receives the turn-off voltage and the diode current flows from the anode to the cathode, the second optical drive electrode can be used to receive the second optical signal to increase the carrier concentration in the P+ and N-type drift regions, thereby increasing the conductivity and decreasing the resistivity in the P+ and N-type drift regions, and thus improving the current-carrying capacity of the FWD.

[0080] For an N-IGBT, the anode 210 of the FWD is connected to the emitter 113 of the N-IGBT, and the cathode 211 of the FWD is connected to the collector 112 of the N-IGBT. When the N-IGBT is turned on, the current can flow from the collector 112 to the emitter 113. When the gate 111 of the N-IGBT receives the turn-off voltage, the current flows from the anode 210 to the cathode 211 of the FWD, achieving a current-draining effect. When the gate 111 receives the turn-off voltage and the current of the power device flows from the anode 210 to the cathode 211, the second optical drive electrode 212 can be used to receive a second optical signal to improve the current-carrying capacity of the power device.

[0081] See Figure 9 , Figure 9This is another timing diagram illustrating the conduction of the power device provided in this application embodiment. For the specific implementation of N-IGBT conduction from time t1 to t5, please refer to Embodiment 1, which will not be elaborated upon here. At time t5, the first optical drive electrode 110 stops receiving the first optical signal. At time t6, the gate 111 of the N-IGBT receives the turn-off voltage, the N-IGBT begins to turn off, and the current of the N-IGBT begins to flow through the FWD. At any time between the start of N-IGBT turn-off and the next start of N-IGBT conduction (e.g., from time t6 to t8), such as at time t6, the second optical drive electrode 212 can receive the second optical signal, increasing the number of electron-hole pairs in the P+ region and the N drift region, increasing the carrier concentration in the P-base region and the N drift region, thereby increasing the conductivity and decreasing the resistivity of the FWD, and thus improving the current-carrying capacity of the FWD. It should be understood that this application embodiment does not limit the duration for which the second optical drive electrode 212 receives the second optical signal.

[0082] It should be understood that during the IGBT turn-on phase, receiving the first optical signal through the first optical drive electrode 110 can increase the concentration of free carriers in the N-type drift region, thereby increasing the conductivity and decreasing the resistivity of the N-type drift region. This improves the IGBT's current-carrying capacity, increases Ic, and enhances the performance of the power device. During freewheeling via the FWD, receiving the second optical signal through the second optical drive electrode 212 can increase the number of electron-hole pairs in the P+ and N-type drift regions, increasing the carrier concentration in the P-base and N-type drift regions. This also increases the FWD's conductivity and decreases its resistivity, further improving the FWD's current-carrying capacity. Therefore, the first optical signal received through the first optical drive electrode 110 and the second optical signal received through the second optical drive electrode 212 can increase the collector current and accelerate the discharge speed, thus improving the IGBT's performance to some extent.

[0083] For a P-IGBT, the anode 210 of the FWD is connected to the collector 112 of the P-IGBT, and the cathode 211 of the FWD is connected to the emitter 113 of the P-IGBT. When the P-IGBT is turned on, current flows from the emitter 113 to the collector 112. When the P-IGBT receives a turn-off voltage, the current flows from the anode 210 to the cathode 211 of the FWD, thus achieving a current discharge effect. When the gate 111 receives a turn-off voltage and the current of the power device flows from the anode 210 to the cathode 211, the second optical drive electrode 212 can be used to receive a second optical signal to improve the current carrying capacity of the power device.

[0084] See Figure 10 , Figure 10 This is another timing diagram illustrating the conduction of the power device provided in an embodiment of this application. For example... Figure 10As shown, the specific implementation of P-IGBT conduction from time t1 to t5 can be found in Embodiment 1, and will not be elaborated further here. At time t5, the first optical drive electrode 110 stops receiving the first optical signal. At time t6, the gate 111 of the P-IGBT receives the turn-off voltage, the P-IGBT begins to turn off, and the current of the P-IGBT begins to flow through the FWD. At any time from the start of P-IGBT turn-off to the next start of P-IGBT conduction (e.g., from time t6 to t8), such as at time t6, the second optical drive electrode 212 receives the second optical signal, increasing the number of electron-hole pairs in the P+ region and N drift region, increasing the carrier concentration in the P-base region and N drift region, causing the FWD conductivity to increase and the resistivity to decrease, thereby improving the FWD's current carrying capacity. It should be understood that the embodiments of this application do not limit the duration for which the second optical drive electrode 212 receives the second optical signal.

[0085] It should be noted that the FWD with the second optical drive electrode can work as a power device alone, or the IGBT with the first optical drive electrode 110 can work as a power device alone, or the IGBT with the first optical drive electrode 110 and the FWD with the second optical drive electrode 212 can work as a whole as a power device, or the IGBT with the first optical drive electrode 110 and the FWD without the second optical drive electrode 212 can work as a whole as a power device. The embodiments of this application are not limited here.

[0086] It should be understood that during the IGBT turn-on phase, the first optical drive electrode 110 receiving the first optical signal can increase the concentration of free carriers in the N-type or P-type drift region, thereby increasing the conductivity and decreasing the resistivity of the N-type or P-type drift region. This improves the IGBT's current-carrying capacity, increases Ic, and enhances the performance of the power device. During freewheeling via the FWD, the second optical drive electrode 212 receiving the second optical signal can increase the carrier concentration in the P+ and N-type drift regions of the diode, further improving the FWD's current-carrying capacity. Therefore, the first optical signal received by the first optical drive electrode 110 and the second optical signal received by the second optical drive electrode 212 can increase the collector current and accelerate the discharge speed, thus improving the IGBT's performance to some extent.

[0087] See Figure 11 , Figure 11This is a schematic diagram of a power conversion device provided in an embodiment of this application. The power conversion device 2 may include a power device 100, a controller 200, and an optical signal generating device 300. The optical signal generating device 300 can be used to generate a first optical signal and transmit the first optical signal to the power device. The power device 100 may include a gate and a first optical driving electrode. Embodiments corresponding to the power device 100 can be found above and will not be elaborated further here. The controller 200 can be used to control the gate 111 to turn on the power device 100. Further, during the turn-on process of the power device 100, the controller 200 can control the optical signal generating device 300 to transmit the first optical signal to the first optical driving electrode to increase the current flowing through the power device 100 when it is turned on. It should be understood that the optical signal generating device 300 may be integrated into the power conversion device 2 or disposed outside the power conversion device 2. When the optical signal generating device 300 is located outside the power conversion device 2, the controller 200 interacts with the optical signal generating device 300 to control the optical signal generating device 300 to generate a first optical signal. The controller 200 can also control the optical signal generating device 300 to turn on and off, thereby controlling the transmission and cessation of the first optical signal output. The optical signal generating device 300 can be an optical module, a laser chip, or a supercontinuum light source; this embodiment does not limit the type of optical signal generating device 300. Optionally, the optical signal generating device 300 can also be integrated into the power device. Furthermore, the optical signal generating device 300 and the power device 100 can be connected via optical fiber to transmit the first optical signal to the power device 100.

[0088] See Figure 12 , Figure 12 This is another structural schematic diagram of the power conversion device provided in this application embodiment. The power device 100 can be electrically connected to the substrate 120 and wrapped with an insulating material 130. An optical fiber 140 for transmitting a first optical signal can be disposed inside the substrate 120. One end of the optical fiber 140 can be connected to the substrate 120, and the other end can also be connected to the optical signal generating device 300. The first optical signal can be transmitted through the substrate 120. Optionally, the first optical signal can also be transmitted through an optical waveguide.

[0089] In one feasible implementation, the power device 100 may further include an emitter 113. The controller 200 may be used to apply a turn-on voltage to the gate to increase the voltage between the gate and the emitter, thereby turning on the power device, or to decrease the voltage between the gate and the emitter, thereby turning on the power device. The structures of N-IGBTs and P-IGBTs are described above and will not be repeated here.

[0090] See Figure 2bThe N-IGBT starts conducting when the voltage (Vce) between the collector 112 and emitter 113 is greater than or equal to the N-IGBT's turn-on voltage, and the voltage (Vge) between the gate 111 and emitter 113 is greater than or equal to the N-IGBT's threshold voltage (denoted as Vg(th), such as 0.7V). See also... Figure 3 Before time t1, Vge < Vg(th), and the N-IGBT is not turned on. At time t1, Vge begins to rise. When Vce is greater than or equal to the turn-on voltage of the N-IGBT, and Vge is greater than or equal to the Vg(th) of the N-IGBT, as at time t2, a channel begins to appear, and a conducting path is formed between the collector 112 and the emitter 113. As Vge increases, a current path is formed from the collector 112 through the N-type drift region, the P-type well region, and the conductive channel to the emitter 113, which is the collector current, denoted as Ic. At time t3, the N-IGBT begins to fully conduct, and Ic begins to increase. At time t4, Vge increases to a high level (e.g., 15V), and the N-IGBT is fully turned on.

[0091] Furthermore, the power device 100 may also include a collector 112. When the voltage between the gate 111 and the emitter 113 is greater than or equal to the first target voltage, the controller 200 can be used to control the optical signal generating device 300 to transmit a first optical signal to the first optical driving electrode 110, thereby increasing the current flowing from the collector 112 to the emitter 113 when the power device 100 is turned on. The current flowing from the collector 112 to the emitter 113 may be the collector current.

[0092] In specific implementations, the first target voltage can be the threshold voltage of the N-IGBT, i.e., Vg(th). When Vge ≥ Vg(th), as... Figure 3 At any time from t2 to t5, the controller 200 can control the optical signal generating device 300 to transmit a first optical signal to the first optical driving electrode 110. When the first optical signal irradiates the N-type drift region, the carrier concentration in the N-type drift region increases, causing the conductivity of the N-type drift region to increase and the resistivity to decrease, thereby increasing the current flowing from the collector 112 to the emitter 113 when the N-IGBT is turned on, i.e., the collector current (Ic). Figure 4 As shown, when Vce = V0, the current value of Ic of IGBT-light is greater than the current value of Ic of IGBT. In other words, receiving the first optical signal at the first optical drive electrode 110 can increase the current flowing through the collector when the N-IGBT is turned on. It should be understood that when Vge ≥ Vg(th), receiving the first optical signal can increase the concentration of charge carriers in the N-type drift region, thereby effectively increasing the current flowing through the N-IGBT (such as Ic).

[0093] It is worth noting that when Vge just begins to be greater than or equal to Vg(th) (e.g., from time t2 to t3), the current flowing through the collector 112 increases from zero, and the N-IGBT cannot exhibit a fully conducting phenomenon. At this time, even if the controller 200 controls the optical signal generating device 300 to transmit the first optical signal to the first optical driving electrode 110 to increase the concentration of charge carriers in the N-type drift region, the effect on improving Ic is very weak. Based on this, the first optical signal can be received when the N-IGBT begins to fully conduct. In other words, the first target voltage can be Vgs_miller. In this way, the first optical driving electrode 110 can receive the first optical signal when the current value of Ic begins to increase, thereby improving the growth rate and magnitude of Ic, and avoiding the waste of the first optical signal compared to the first target voltage being Vg(th).

[0094] Understandably, when the Vge of the N-IGBT is greater than or equal to the first target voltage, the controller 200 controls the optical signal generating device 300 to transmit the first optical signal to the first optical driving electrode 110, which can increase the concentration of free carriers in the N-type drift region. According to the conductivity modulation effect, as the concentration of carriers increases, the conductivity of the N-type drift region can be increased, the resistance of the N-type drift region can be reduced, and the on-state voltage drop of the N-IGBT can be reduced to a certain extent, thereby increasing Ic and reducing the power loss of the N-IGBT, and improving the performance of the power device 100.

[0095] See Figure 5b When the voltage between the collector 112 and emitter 113 of the P-IGBT is less than or equal to the turn-on voltage (i.e., the turn-on voltage of the P-IGBT, which is negative), and the voltage between the gate 111 and emitter 113 is less than or equal to the threshold voltage of the P-IGBT (e.g., -0.7V), the P-IGBT starts to conduct.

[0096] See Figure 6 Before time t1, Vge > Vg(th), and the P-IGBT is not turned on. At time t1, Vge of the P-IGBT gradually decreases. When Vce is less than or equal to the turn-on voltage of the P-IGBT, and Vge ≤ Vg(th), as at time t2, a channel begins to appear, and a conduction path is formed between the collector 112 and the emitter 113. As Vge decreases, a current path is formed from the emitter 113 to the collector 112, which is the collector current, denoted as Ic. At time t3, the P-IGBT begins to fully conduct, and Ic begins to increase. At time t4, Vge decreases to a low level (e.g., -15V), and the P-IGBT is fully turned on.

[0097] Furthermore, the power device 100 may also include a collector 112. When the voltage between the gate 111 and the emitter 113 is less than or equal to the first target voltage, the controller 200 can be used to control the optical signal generating device 300 to transmit a first optical signal to the first optical driving electrode 110, thereby increasing the current flowing from the emitter 113 to the collector 112 when the power device 100 is turned on. The current flowing from the emitter 113 to the collector 112 may be the collector current.

[0098] In specific implementations, the second target voltage can be the threshold voltage of the P-IGBT, i.e., Vg(th). When Vge ≤ Vg(th), as... Figure 6 At any time from t2 to t5, the controller 200 can control the optical signal generating device 300 to transmit a first optical signal to the first optical driving electrode 110. When the first optical signal irradiates the P-type drift region, the carrier concentration in the P-type drift region increases, causing the conductivity of the P-type drift region to increase and the resistivity to decrease, thereby increasing the current flowing from the emitter 113 to the collector 112 when the P-IGBT is turned on, i.e., the collector current (Ic). Figure 7 As shown, when Vce = V0', the current value of Ic of IGBT-light is greater than the current value of Ic of IGBT. In other words, receiving the first optical signal during the P-IGBT conduction process can increase the current flowing through the collector when the P-IGBT is turned on. It should be understood that when Vge ≤ Vg(th), receiving the first optical signal can increase the carrier concentration in the P-type drift region, thereby effectively increasing the current flowing through the P-IGBT (such as Ic).

[0099] It should be understood that when Vge is initially less than or equal to Vg(th) (e.g., from time t2 to t3), the current flowing through collector 112 increases from zero, preventing the P-IGBT from fully conducting. At this time, even if the controller 200 controls the optical signal generating device 300 to transmit a first optical signal to the first optical driving electrode 110 to increase the carrier concentration in the N-type drift region, the effect on Ic improvement is very weak. Therefore, the first optical signal can be received when the P-IGBT begins to fully conduct. In other words, the first target voltage can be Vgs_miller. This allows the first optical driving electrode 110 to receive the first optical signal when the current value of Ic begins to increase, thereby increasing the growth rate and magnitude of Ic, avoiding waste of the first optical signal compared to using a first target voltage of Vg(th).

[0100] Understandably, when the Vge of the P-IGBT is less than or equal to the second target voltage, the controller 200 can control the optical signal generating device 300 to transmit to the first optical driving electrode 110, which can increase the concentration of free carriers in the P-type drift region. According to the conductivity modulation effect, as the concentration of carriers increases, the conductivity of the P-type drift region can be increased or the resistance of the P-type drift region can be reduced, further reducing the on-state voltage drop of the P-IGBT to a certain extent, thereby increasing Ic and reducing the power loss of the P-IGBT, and improving the performance of the power device 100.

[0101] In one feasible implementation, the controller 200 can also be used to control the optical signal generating device 300 to stop transmitting the first optical signal to the first optical driving electrode 110. Further, when the optical signal generating device 300 is transmitting the first optical signal to the first optical driving electrode 110, the controller 200 can control the gate 111 to receive a turn-off voltage to turn off the power device 100.

[0102] In a specific implementation, taking N-IGBT as an example, the controller 200 needs to first control the optical signal generating device 300 to stop the input of the first optical signal, and then apply a turn-off voltage to the gate of the IGBT. For example... Figure 4 As shown, at time t5, when the optical signal generating device 300 stops transmitting the first optical signal to the first optical driving electrode 110, the first optical driving electrode 110 no longer receives the first optical signal. Then, at time t6, the controller 200 can apply a turn-off voltage to the gate 111 of the N-IGBT, controlling Vge to decrease, and the N-IGBT begins to turn off. At time t7, Vge becomes low (e.g., -10V), and the N-IGBT is completely turned off.

[0103] Similarly, taking P-IGBT as an example, controller 200 needs to first control optical signal generation device 300 to stop the input of the first optical signal before applying a turn-off voltage to the gate of the IGBT. Figure 6 As shown, at time t5, when the optical signal generating device 300 stops transmitting the first optical signal to the first optical driving electrode 110, the first optical driving electrode 110 no longer receives the first optical signal. Then, the controller 200 can apply a turn-off voltage to the gate 111 of the N-IGBT, controlling Vge to rise, and the P-IGBT begins to turn off. When Vge becomes high (e.g., 10V), the P-IGBT is completely turned off.

[0104] It is understandable that the controller 200 controls the optical signal generating device 300 to transmit the first optical signal to the first optical driving electrode 110, which can increase the concentration of charge carriers in the drift region of the IGBT, thereby increasing the conductivity of the drift region and reducing the resistance of the drift region. Therefore, when turning off the IGBT, the reception of the first optical signal can be stopped first, and then the IGBT can be turned off. This can avoid the first optical signal from hindering the IGBT from turning off, and can also avoid signal confusion, data errors or abnormal equipment status.

[0105] When the power device includes a field-controlled diode (FWD), the IGBT and FWD are connected in reverse parallel. The FWD maintains a continuous current flow, preventing reverse voltage damage to the IGBT. Specifically, the emitter of the N-IGBT is connected to the anode of the FWD, and the collector of the N-IGBT is connected to the cathode of the FWD. Similarly, the emitter of the P-IGBT is connected to the cathode of the FWD, and the collector of the P-IGBT is connected to the anode of the FWD. Receiving a second optical signal through the second optical drive electrode of the FWD can accelerate the current discharge speed, as detailed in the following embodiment.

[0106] In one feasible implementation, the power device 100 may include a light-driven diode (FWD), which may include an anode, a cathode, and a second light-driving electrode. When the gate 111 receives a turn-off voltage and the current in the FWD flows from the anode to the cathode, the controller 200 can control the optical signal generating device 300 to transmit a second optical signal to the second light-driving electrode to improve the current-carrying capacity of the FWD. A circuit diagram and cross-section of the FWD can be found in [reference needed]. Figure 8a and Figure 8b The corresponding embodiments will not be described in detail here. When the power device 100 includes IGBT and FWD, the optical path propagation direction of the first optical signal and the second optical signal in the substrate 120 can be changed by means of grating, coupler, time-reflecting mirror, optical fiber bending, etc., so as to achieve the effect of transmitting the first optical signal and the second optical signal. In this case, the solid line can represent the propagation path of the first optical signal and the dashed line can represent the propagation path of the second optical signal.

[0107] In specific implementations, for N-IGBTs such as Figure 9As shown, the specific implementation of the N-IGBT conduction from time t1 to t5 can be found in the previous text and will not be repeated here. At time t5, the controller 200 can be used to control the optical signal generating device 300 to stop transmitting the first optical signal to the first optical driving electrode 110. At time t6, the controller 200 can apply a turn-off voltage to the gate 111 of the N-IGBT, and the N-IGBT begins to turn off, and the current of the N-IGBT begins to flow through the FWD. At any time from the start of the N-IGBT turning off to the next start of the N-IGBT conducting (such as from time t6 to t8), such as at time t6, the controller 200 can be used to control the optical signal generating device 300 to transmit the second optical signal to the second optical driving electrode 212, increasing the number of electron-hole pairs in the P+ region and the N drift region, increasing the carrier concentration in the P base region and the N drift region, increasing the conductivity of the FWD and decreasing the resistivity, thereby improving the current carrying capacity of the FWD. It should be understood that the embodiments of this application do not limit the duration for which the second optical drive electrode 212 receives the second optical signal. It should be understood that when the FWD is in operation, the controller 200 controls the optical signal generating device 300 to transmit the second optical signal to the second optical drive electrode 212, which can increase the number of electron-hole pairs in the P+ region and the N drift region, thereby improving the current carrying capacity of the FWD.

[0108] For P-IGBT, such as Figure 10 As shown, the specific implementation of P-IGBT conduction from time t1 to t5 can be found in the previous text and will not be repeated here. At time t5, the controller 200 can be used to control the optical signal generating device 300 to stop transmitting the first optical signal to the first optical driving electrode 110. At time t6, the controller 200 can apply a turn-off voltage to the gate 111 of the P-IGBT, and the P-IGBT begins to turn off, and the current of the P-IGBT begins to flow through the FWD. At any time from the start of P-IGBT turn-off to the next start of P-IGBT conduction (such as from time t6 to t8), such as at time t6, the controller 200 can be used to control the optical signal generating device 300 to transmit the second optical signal to the second optical driving electrode 212, increasing the number of electron-hole pairs in the P+ region and N drift region, increasing the carrier concentration in the P base region and N drift region, increasing the conductivity of the FWD and decreasing the resistivity, thereby improving the current carrying capacity of the FWD. It should be understood that the embodiments of this application do not limit the duration for which the second optical drive electrode 212 receives the second optical signal.

[0109] It should be noted that the FWD with the second optical driving electrode can work alone as a power device 100, or the IGBT with the first optical driving electrode 110 can work alone as a power device 100, or the IGBT with the first optical driving electrode 110 and the FWD with the second optical driving electrode 212 can work as a whole as a power device 100, or the IGBT with the first optical driving electrode 110 and the FWD without the second optical driving electrode 212 can work as a whole as a power device 100. The embodiments of this application are not limited here.

[0110] It should be understood that during the IGBT conduction phase, the controller 200 controls the optical signal generating device 300 to transmit the first optical signal to the first optical driving electrode 110, which can increase the concentration of free carriers in the N-type drift region or P-type drift region, thereby increasing the conductivity and decreasing the resistivity of the N-type drift region or P-type drift region. This improves the current-carrying capacity of the IGBT, increases Ic, and enhances the performance of the power device. During freewheeling via FWD, the controller 200 can control the optical signal generating device 300 to transmit the second optical signal to the second optical driving electrode 212, which can increase the carrier concentration in the P+ and N-type drift regions of the diode, thereby improving the diode's current-carrying capacity.

[0111] Please see Figure 13 , Figure 13 This is a flowchart illustrating a control method for a power conversion device provided in an embodiment of this application. The power conversion device may include a controller, a power device, and an optical signal generation device. The optical signal generation device can generate a first optical signal and transmit the first optical signal to the power device. The power device may include a gate and a first optical driving electrode. The control method for the power device provided in this embodiment is applicable to… Figure 11 The controller in the corresponding specific implementation. Specifically, the control method for the power conversion device may include the following steps.

[0112] Step S101: Control the gate to turn on the power device.

[0113] Step S102: During the power device conduction process, the optical signal generating device is controlled to transmit the first optical signal to the first optical driving electrode to increase the current flowing through the power device when the power device is conducted.

[0114] In one feasible implementation, the power device further includes an emitter. The control gate to turn on the power device includes: controlling the gate to receive a turn-on voltage to increase the voltage between the gate and the emitter, thereby turning on the power device; or, decreasing the voltage between the gate and the emitter, thereby turning on the power device. IGBTs can be classified into N-IGBTs and P-IGBTs according to their channel type. The working principles and structures of N-IGBTs and P-IGBTs can be found above and will not be elaborated upon here.

[0115] In specific implementations, for N-IGBTs, the condition for N-IGBT turn-on is that the voltage between the gate and emitter (Vge) of the N-IGBT must be greater than or equal to the threshold voltage (Vg(th)) of the N-IGBT. It should be noted that those skilled in the art should understand that the voltage between the collector and emitter (Vce) of the N-IGBT being greater than or equal to the turn-on voltage of the N-IGBT is a necessary condition for N-IGBT turn-on. In other words, the N-IGBT turn-on mentioned in the embodiments of this application is achieved under the premise that the Vce of the N-IGBT is greater than or equal to the turn-on voltage of the N-IGBT. Based on this, when the Vce of the N-IGBT is greater than or equal to the turn-on voltage of the N-IGBT, a turn-on voltage can be applied to the gate of the N-IGBT to increase Vge. When Vge ≥ Vg(th), the conductive channel inside the N-IGBT begins to form, and the N-IGBT begins to conduct. Then, when Vge ≥ Vgs_miller, the N-IGBT is fully turned on.

[0116] For P-IGBTs, the condition for P-IGBT turn-on is that the voltage between the gate and emitter (Vge) must be less than or equal to the threshold voltage (Vg(th)). It should be noted that those skilled in the art should understand that the voltage between the collector and emitter (Vce) must be less than or equal to the turn-on voltage for P-IGBT turn-on. In other words, the P-IGBT turn-on mentioned in this application embodiment is achieved under the premise that Vce is less than or equal to the turn-on voltage. Based on this, when Vce is less than or equal to the turn-on voltage, a turn-on voltage can be applied to the gate to reduce Vge. When Vge ≤ Vg(th), the conductive channel inside the P-IGBT begins to form, and the P-IGBT begins to conduct. Then, when Vge ≤ Vgs_miller, the P-IGBT is fully turned on.

[0117] It should be understood that by applying a conduction voltage to the gate, the opening of the internal conduction channel of the IGBT can be controlled, thereby controlling the conduction state of the IGBT and realizing the current flow between the collector and emitter of the IGBT.

[0118] In one feasible implementation, the power device further includes a collector. The method of controlling the optical signal generating device to transmit a first optical signal to the first optical driving electrode during the power device conduction process to increase the current flowing through the power device when the power device is turned on includes: when the voltage between the gate and the emitter is detected to be greater than or equal to a first target voltage, controlling the optical signal generating device to transmit a first optical signal to the first optical driving electrode to increase the current flowing from the collector to the emitter when the power device is turned on.

[0119] In practical implementation, for N-IGBTs, the first target voltage can be the threshold voltage of the N-IGBT, i.e., Vg(th). When Vge ≥ Vg(th), the N-IGBT starts to conduct. At this time, controlling the optical signal generation device to transmit the first optical signal to the first optical driving electrode can increase the carrier concentration in the N-type drift region, thereby increasing the conductivity and decreasing the resistivity of the N-type drift region, thus increasing the current flowing from the collector to the emitter and improving the performance of the power device.

[0120] Optionally, the first target voltage can be Vgs_miller of the N-IGBT. When Vge ≥ Vgs_miller of the N-IGBT, the N-IGBT is fully turned on. At this time, controlling the optical signal generating device to transmit the first optical signal to the first optical driving electrode can increase the carrier concentration in the N-type drift region, thereby increasing the conductivity and decreasing the resistivity of the N-type drift region, thus increasing the current flowing from the collector to the emitter and improving the performance of the power device. In addition, compared with the first target voltage being Vg(th), the power consumption of the optical signal generating device can be reduced, avoiding the waste of the first optical signal.

[0121] In one feasible implementation, the power device further includes a collector. The method of controlling the optical signal generating device to transmit a first optical signal to the first optical driving electrode during the power device conduction process to increase the current flowing through the power device when the power device is turned on includes: when the voltage between the gate and the emitter is detected to be less than or equal to a first target voltage, controlling the optical signal generating device to transmit a first optical signal to the first optical driving electrode to increase the current flowing from the emitter to the collector when the power device is turned on.

[0122] In practical implementation, for P-IGBTs, the first target voltage can be the threshold voltage of the P-IGBT, i.e., Vg(th). When Vge ≤ Vg(th), the P-IGBT starts to conduct. At this time, controlling the optical signal generation device to transmit the first optical signal to the first optical driving electrode can increase the carrier concentration in the P-type drift region, thereby increasing the conductivity and decreasing the resistivity of the P-type drift region, thus increasing the current flowing from the emitter to the collector and improving the performance of the power device.

[0123] Optionally, the first target voltage can be Vgs_miller of the P-IGBT. When Vge ≤ Vgs_miller, the P-IGBT is fully turned on. At this time, controlling the optical signal generating device to transmit the first optical signal to the first optical driving electrode can increase the carrier concentration in the P-type drift region, thereby increasing the conductivity and decreasing the resistivity of the P-type drift region, thus increasing the current flowing from the emitter to the collector and improving the performance of the power device. In addition, compared with the first target voltage being Vg(th), the power consumption of the optical signal generating device can be reduced, avoiding the waste of the first optical signal.

[0124] In one feasible implementation, the method further includes: controlling the optical signal generating device to stop transmitting the first optical signal to the first optical driving electrode; and controlling the gate to turn off the power device when the first optical driving electrode stops receiving the first optical signal.

[0125] It should be understood that the controllable optical signal generating device can transmit the first optical signal to the first optical driving electrode, thereby increasing the concentration of charge carriers in the drift region of the IGBT, thereby increasing the conductivity of the drift region and reducing the resistance of the drift region. Therefore, when turning off the IGBT, the optical signal generating device can be controlled to stop transmitting the first optical signal to the first optical driving electrode before turning off the IGBT. This can prevent the first optical signal from hindering the turn-off of the IGBT, and can also avoid signal confusion, data errors or abnormal equipment status.

[0126] In one feasible implementation, the power device further includes a diode, which includes an anode, a cathode, and a second optical driving electrode. The method further includes: when the gate receives a turn-off voltage and the current of the diode is detected flowing from the anode to the cathode, controlling the optical signal generating device to transmit a second optical signal to the second optical driving electrode to improve the current carrying capacity of the diode.

[0127] It should be understood that during the IGBT's turn-on phase, transmitting a first optical signal to the first optical drive electrode via an optical signal generation device can increase the current flowing through the collector when the IGBT is turned on. When the IGBT is turned off, freewheeling can be achieved through the diode. At this time, the optical signal generation device can be controlled to transmit a second optical signal to the second optical drive electrode, which can increase the carrier concentration in the P+ and N-type drift regions within the diode, thereby improving the current-carrying capacity and accelerating the discharge speed. This can improve the IGBT's performance to some extent.

Claims

1. A power device, characterized in that, The power device includes a gate and a first optical driving electrode; The gate is used to turn on the power device; During the conduction of the power device, the first optical driving electrode is used to receive the first optical signal to increase the current flowing through the power device when the power device is turned on.

2. The power device according to claim 1, characterized in that, The power device also includes an emitter; The gate is used to receive the turn-on voltage to increase the voltage between the gate and the emitter, thereby turning on the power device, or to decrease the voltage between the gate and the emitter, thereby turning on the power device.

3. The power device according to claim 2, characterized in that, The power device further includes a collector; When the voltage between the gate and the emitter is greater than or equal to the first target voltage, the first optical driving electrode is used to receive the first optical signal to increase the current flowing from the collector to the emitter when the power device is turned on.

4. The power device according to claim 2, characterized in that, The power device further includes a collector; When the voltage between the gate and the emitter is less than or equal to the second target voltage, the first optical driving electrode is used to receive the first optical signal to increase the current flowing from the emitter to the collector when the power device is turned on.

5. The power device according to claim 1, characterized in that, When the first optical driving electrode stops receiving the first optical signal, the gate is also used to receive a turn-off voltage to turn off the power device.

6. The power device according to claim 5, characterized in that, The power device includes a diode, and the diode includes an anode, a cathode, and a second optical driving electrode; When the gate receives a turn-off voltage and the current of the diode flows from the anode to the cathode, the second light-driving electrode is used to receive a second optical signal to improve the current-carrying capacity of the diode.

7. A power conversion device, characterized in that, The power conversion device includes a controller, a power device, and an optical signal generation device. The optical signal generation device is used to generate a first optical signal and transmit the first optical signal to the power device. The power device includes a gate and a first optical driving electrode. The controller is used to control the gate to turn on the power device; During the conduction of the power device, the controller is used to control the optical signal generating device to transmit the first optical signal to the first optical driving electrode, so as to increase the current flowing through the power device when the power device is turned on.

8. The power device according to claim 7, characterized in that, The power device also includes an emitter; The controller is configured to apply a conduction voltage to the gate to increase the voltage between the gate and the emitter, thereby turning on the power device; or, to decrease the voltage between the gate and the emitter, thereby turning on the power device.

9. The power device according to claim 8, characterized in that, The power device further includes a collector; When the voltage between the gate and the emitter is greater than or equal to the first target voltage, the controller is used to control the optical signal generating device to transmit the first optical signal to the first optical driving electrode, so as to increase the current flowing from the collector to the emitter when the power device is turned on.

10. The power device according to claim 8, characterized in that, The power device further includes a collector; When the voltage between the gate and the emitter is less than or equal to the second target voltage, the controller is used to control the optical signal generating device to transmit the first optical signal to the first optical driving electrode, so as to increase the current flowing from the emitter to the collector when the power device is turned on.

11. The power device according to claim 7, characterized in that, The controller is also used to control the optical signal generating device to stop transmitting the first optical signal to the first optical driving electrode; When the optical signal generating device stops transmitting the first optical signal to the first optical driving electrode, the controller is further configured to control the gate to receive a turn-off voltage to turn off the power device.

12. The power device according to claim 11, characterized in that, The power device further includes a diode, which includes an anode, a cathode, and a second optical driving electrode. When the gate receives a turn-off voltage and the current of the diode flows from the anode to the cathode, the controller controls the optical signal generating device to transmit a second optical signal to the second optical driving electrode to improve the current carrying capacity of the diode.

13. A control method for a power conversion device, characterized in that, The power conversion device includes a controller, a power device, and an optical signal generation device. The optical signal generation device is used to generate a first optical signal and transmit the first optical signal to the power device. The power device includes a gate and a first optical driving electrode. The method includes: Control the gate to turn on the power device; During the conduction of the power device, the optical signal generating device is controlled to transmit a first optical signal to the first optical driving electrode to increase the current flowing through the power device when the power device is turned on.

14. The method according to claim 13, characterized in that, The power device further includes an emitter, and controlling the gate to turn on the power device includes: The gate receives a turn-on voltage to increase the voltage between the gate and the emitter, thereby turning on the power device; or, the voltage between the gate and the emitter is decreased, thereby turning on the power device.

15. The method according to claim 14, characterized in that, The power device further includes a collector, and during the conduction of the power device, controlling the optical signal generating device to transmit a first optical signal to the first optical driving electrode to increase the current flowing through the power device when it is turned on includes: When the voltage between the gate and the emitter is detected to be greater than or equal to the first target voltage, the optical signal generating device is controlled to transmit the first optical signal to the first optical driving electrode to increase the current flowing from the collector to the emitter in the power device.

16. The method according to claim 14, characterized in that, The power device further includes a collector. During the conduction process of the power device, controlling the optical signal generating device to transmit a first optical signal to the first optical driving electrode to increase the current flowing through the power device when it is turned on includes: When the voltage between the gate and the emitter is detected to be less than or equal to the second target voltage, the optical signal generating device is controlled to transmit the first optical signal to the first optical driving electrode to increase the current flowing from the emitter to the collector when the power device is turned on.

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