A power semiconductor device driving system based on laser transmission

Abstract

This invention relates to a power semiconductor device driving system based on laser transmission. A main control unit outputs power supply and control signals for the power semiconductor device, which are transmitted over long distances via an energy laser beam and a signal laser beam with the same direction and repetition frequency. The laser energy receiving unit then converts the signals through photoelectric conversion and transmits them to the drive power supply unit for driving. Simultaneously, the laser signal receiving unit recovers the control signals through photoelectric conversion and outputs them to the power semiconductor device via the control drive unit for control. This design enables long-distance signal and energy transmission, possesses strong electromagnetic noise suppression capabilities, and achieves electrical isolation between the system's power and signal generation ends. This reduces common-mode noise transmitted from the local device to the remote end to zero, effectively improving the system's operational safety. It can be effectively applied in scenarios such as mining, oil exploration, and high-voltage power grid operations.

Description

Technical Field

[0001] This invention relates to a power semiconductor device driving system based on laser transmission, belonging to the field of electronic drive system technology. Background Technology

[0002] Gate drivers are crucial peripheral circuits for power semiconductor devices, providing basic drive energy and offering signal isolation and protection functions. They play a vital role in the safe and reliable operation of power semiconductor devices. Gate drivers consist of two potential terminals: an analog side and a digital side. Commonly used gate drivers for half-bridge modules include... Figure 1 As shown, the half-bridge driver consists of two parts: the upper transistor and the lower transistor. The main functional modules include a drive signal isolation chip and an isolation power supply module.

[0003] Signal isolation primarily employs four methods: capacitive isolation, magnetic coupling isolation, optical coupling isolation, and fiber optic isolation. Capacitive, magnetic, and optical coupling isolation all rely on signal isolation chips. Capacitive isolation achieves electrical isolation by generating semiconductor capacitors within the chip; magnetic coupling transmits signals through a coupling coil built into the chip; and optical coupling isolation mainly uses LEDs and optical receivers for isolation. These solutions are relatively small in size, which is beneficial for improving system integration. However, their isolation voltage and common-mode noise suppression capabilities are limited. When applied in high-voltage, high-dv / dt scenarios such as high-power microwave repetition rate transmitters, they suffer from significant noise interference and limited voltage withstand capability. Fiber optic isolation achieves complete electrical isolation, and the distance between the transmitter and receiver is relatively large, resulting in strong voltage and noise isolation capabilities. However, fiber optic communication also relies on the fiber itself, thus preventing true wireless signal transmission. The longer the isolation distance, the longer the fiber optic communication line is required, leading to increased system costs.

[0004] In addition to signal isolation, gate driving requires an isolated power supply to power the drive and simultaneously change its potential. Depending on the input voltage, there are various forms of isolated power supplies. AC-powered isolated power supplies are typically used in rectifiers or inverter clocks. They can use an uncontrolled rectifier circuit to draw power from the AC terminal and convert it to DC, then use a step-down isolated DC / DC circuit to convert the high-voltage DC to the required low-voltage DC such as 24V, 12V, or 5V. Other solutions directly use isolated DC / DC circuits, whose basic circuit structures include flyback circuits, push-pull circuits, forward circuits, LLC resonant circuits, and others. Some research proposals also suggest using wireless power transfer coils for electrically isolated power transmission.

[0005] The above-mentioned solution, employing an isolated DC / DC converter in practical applications, relies solely on a transformer for long-distance power transmission. However, the coupling between the primary and secondary windings of the transformer generates parasitic capacitance, which in turn causes common-mode current (dv / dt) to flow from the analog side to the noise-sensitive digital side, threatening the system's safe operation. Furthermore, the isolation voltage of the isolated DC / DC converter depends on the transformer's insulation design; a higher isolation voltage requires a thicker transformer isolation layer, increasing both the transformer's design complexity and the system's size.

[0006] Existing technologies using wireless power transfer coils can achieve good voltage isolation. However, the transmitting and receiving coils cannot be too far apart; longer transmission distances lead to an exponential decrease in transmitted power. Therefore, the two coils typically need to be kept in a relatively close spatial arrangement. Furthermore, when the coil area is large and the distance is short, the high dv / dt voltage between the transmitting and receiving ends can generate common-mode current, affecting the safe operation of the system. Some research has proposed power transmission via optical fiber. This method can achieve complete electrical isolation and has strong common-mode rejection capability; however, it still relies on the optical fiber carrier, and the transmission efficiency is typically below 50%, decreasing exponentially with increasing fiber length, thus failing to achieve true wireless power transfer.

[0007] Because the parasitic inductance of the gate drive circuit has a significant impact on the gate voltage, a high inductance can lead to abnormal gate voltage, potentially causing the IGBT or MOSFET to turn on incorrectly during turn-off due to crosstalk or oscillation. Therefore, to reduce the parasitic inductance of the drive circuit, the output of the gate drive should be placed close to the device. This can be achieved by using an isolated chip and isolated DC / DC circuit for the gate drive, and a DSP, FPGA, or other control unit for the PWM signal generation. Simultaneously, the drive power supply must also be placed near the converter unit to avoid electromagnetic noise interference introduced over long distances.

[0008] Placing the power side (analog) and control side (digital) of the converter close together offers the advantage of faster transmission. However, this poses certain safety risks in some applications. These risks include: the analog side has higher voltage and greater noise; when the two sides are close, the noise can easily propagate to the digital side via wireless noise, causing crosstalk, false start-ups, and other problems, ultimately threatening system safety. In practical applications, remote gate signal control is preferred in certain scenarios, such as high-temperature, high-radiation, and low-temperature environments. In these cases, it is desirable to place the signal processing unit remotely and control the local converter system via wireless transmission.

[0009] To address these needs, the industry has proposed various methods in recent years, such as incorporating wireless power transfer to achieve electrical isolation. However, wireless power transfer also requires coupling coils for electromagnetic field exchange, but this method cannot achieve ultra-long-distance power transfer. Signal transmission can utilize wireless communication protocols such as NFC and Bluetooth, but wireless communication involves encoding and decoding, introducing significant latency. Furthermore, wireless communication is highly susceptible to external electromagnetic interference, and distortion of critical information can cause system malfunctions. Summary of the Invention

[0010] The technical problem to be solved by the present invention is to provide a power semiconductor device driving system based on laser transmission, which can realize long-distance transmission of signals and energy, has extremely strong electromagnetic noise suppression capability, and can be effectively applied to mining, oil exploration, high-voltage power grid operations and other scenarios. It realizes remote transmission of control signals and completely isolates the control side and the converter side, greatly increasing operational safety.

[0011] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The present invention designs a power semiconductor device driving system based on laser transmission, including a main control unit, a laser energy receiving unit, a driving power supply unit, a laser signal receiving unit, and a control driving unit. The main control unit receives the detection current and detection voltage from the power semiconductor device, calculates and outputs the power supply signal and control signal for the power semiconductor device, and then sends them to the laser energy receiving unit and the driving power supply unit through the energy laser beam and the signal laser beam with the same direction and repetition frequency, respectively.

[0012] The laser energy receiving unit, based on the received laser beam, outputs corresponding electrical energy to the drive power supply unit via photoelectric conversion. The drive power supply unit, based on the received electrical energy, provides a reference voltage to the power semiconductor device and a power supply voltage to the control drive unit.

[0013] The laser signal receiving unit obtains the control electrical signal for the power semiconductor device through photoelectric conversion based on the received laser signal beam, and outputs it to the control drive unit. The control drive unit generates a drive control electrical signal corresponding to the received control electrical signal based on the received power supply voltage, and outputs it to the power semiconductor device to realize control.

[0014] As a preferred embodiment of the present invention, it further includes a first laser emitting end and a laser beam splitter. The main control unit receives the detection current and detection voltage from the power semiconductor device, and calculates and generates an electrical signal, which is output to the first laser emitting end. The electrical signal includes a power supply signal and a control signal for the power semiconductor device. The first laser emitting end generates a laser signal with the same direction and repetition frequency based on the received electrical signal, and outputs it to the laser beam splitter. The laser beam splitter splits the received laser signal into two beams to obtain an energy laser beam and a signal laser beam for the power semiconductor device.

[0015] As a preferred embodiment of the present invention, it further includes a second laser emitting end and a third laser emitting end. The main control unit calculates and obtains the power supply signal and control signal for the power semiconductor device, and outputs them to the second laser emitting end and the third laser emitting end, respectively. The second laser emitting end generates an energy laser beam with the same direction and repetition frequency according to the received power supply signal, and outputs it to the laser energy receiving unit. The third laser emitting end generates a signal laser beam with the same direction and repetition frequency according to the received control signal, and outputs it to the laser signal receiving unit.

[0016] As a preferred embodiment of the present invention: the drive power supply unit includes a DC voltage regulator circuit, which includes a boost circuit, a low dropout linear regulator (LDO), and a resistor R. D Zener diode Z D The system includes two capacitors. The input terminal of the boost converter circuit forms the input terminal of the DC voltage regulator circuit, which is also the input terminal of the drive power supply unit. The output terminal of the boost converter circuit is connected to the input terminal of the low dropout linear regulator (LDO), and the positive output terminal of the LDO is connected to resistor R. D One end of one of the capacitors and one end of another are connected together, and the connection point forms the positive output terminal of the DC voltage regulator circuit, which is also the positive output terminal of the drive power supply unit, used to output the positive drive voltage V. dr_on To the control drive unit; the negative output terminal of the low dropout linear regulator (LDO); and the Zener diode Z. D The anode of one capacitor, one end of another capacitor, and the other two capacitors are connected together, and the connection point forms the negative output terminal of the DC voltage regulator circuit, which is also the negative output terminal of the drive power supply unit, used to output the negative drive voltage V. dr_off To the control drive unit; resistor R D The other end, Zener diode Z D The cathode, the other end of one capacitor, and the other end of another capacitor are connected together, and the connection point constitutes the reference voltage output terminal of the DC voltage regulator circuit, that is, the reference voltage output terminal of the drive power supply unit, which is used to output the reference voltage to the power semiconductor device.

[0017] As a preferred embodiment of the present invention: the drive power supply unit further includes a battery, the positive terminal of which is connected to the positive terminal of the DC voltage regulator circuit input, and the negative terminal of which is connected to the positive terminal of the DC voltage regulator circuit input.

[0018] As a preferred embodiment of the present invention: the laser signal receiving unit includes a photodiode D PIN ,inductance ,capacitance Operational amplifier OP1, comparator CMP, and photodiode D PIN The photosensitive end forms the input end of the laser signal receiving unit, used to receive the signal laser beam; photodiode D PIN negative electrode, capacitor One end of the inductor One end of the capacitor, the inverting input of operational amplifier OP1, and the capacitor are connected together. The other end, inductor The other end, the output of operational amplifier OP1, and the positive input of comparator CMP are connected together. The output of comparator CMP constitutes the output of the laser signal receiving unit, used to output control electrical signals for power semiconductor devices. The positive power supply terminals of operational amplifier OP1 and comparator CMP are respectively connected to external voltages. Photodiode D PIN The positive terminal of the DC-DC converter, the positive input terminal of operational amplifier OP1, the negative power supply terminal of operational amplifier OP1, and the negative power supply terminal of comparator CMP are all connected to the negative drive voltage output by the DC-DC regulator circuit. The inverting input terminal of comparator CMP is connected to a preset reference voltage. .

[0019] As a preferred embodiment of the present invention: the control drive unit includes a PMOS transistor, an NMOS transistor, and an inverter, wherein the input terminal of the inverter constitutes the input terminal of the control drive unit for receiving the control electrical signal output by the laser signal receiving unit; the gate of the PMOS transistor, the gate of the NMOS transistor, and the output terminal of the inverter are connected together, the source of the PMOS transistor is connected to the positive drive voltage in the power supply voltage output by the drive power supply unit; the drain of the PMOS transistor is connected to the drain of the NMOS transistor, and the connection position constitutes the output terminal of the control drive unit for outputting the drive control electrical signal to the power semiconductor device, and the source of the NMOS transistor is connected to the negative drive voltage in the power supply voltage output by the drive power supply unit.

[0020] As a preferred embodiment of the present invention: the output terminal of the control drive unit is connected in series with a drive resistor. Then, docking with power semiconductor devices.

[0021] The power semiconductor device driving system based on laser transmission described in this invention has the following technical advantages compared with the prior art:

[0022] This invention presents a power semiconductor device driving system based on laser transmission. A main control unit outputs power supply and control signals for the power semiconductor device, which are transmitted over long distances via an energy laser beam and a signal laser beam with the same direction and repetition frequency. The laser energy receiving unit then converts the signals through photoelectric conversion and sends them to the drive power supply unit for driving. Simultaneously, the laser signal receiving unit recovers the control signals through photoelectric conversion and outputs them to the power semiconductor device via the control drive unit for control. This design enables long-distance signal and energy transmission, possesses strong electromagnetic noise suppression capabilities, and achieves electrical isolation between the converter's power end and signal generation end, reducing common-mode noise transmitted from the local device to the remote end to zero. This effectively improves the system's operational safety and can be effectively applied in scenarios such as mining, oil exploration, and high-voltage power grid operations. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the gate drive structure for a half-bridge module in the prior art;

[0024] Figure 2 This is a schematic diagram of the structure of an embodiment of the system designed in this invention;

[0025] Figure 3 This is a schematic diagram of the structure of Embodiment 2 of the system designed in this invention;

[0026] Figure 4 This is a schematic diagram of a motor-driven system.

[0027] Figure 5 This is a schematic diagram of a typical laser beam splitter.

[0028] Figure 6 This is a schematic diagram of a typical transmission waveform;

[0029] Figure 7 This is a schematic diagram of the DC voltage regulator circuit in the design of this invention;

[0030] Figure 8 This is a schematic diagram of the laser signal receiving unit in the design of this invention;

[0031] Figure 9 This is a schematic diagram of the structure of Embodiment 3 of the system designed in this invention;

[0032] Figure 10 This is an internal waveform diagram of the third embodiment of the design system of the present invention. Detailed Implementation

[0033] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0034] The present invention designs a power semiconductor device driving system based on laser transmission. In practical applications, it is used to drive and control power semiconductor devices such as MOSFETs, IGBTs, and GTOs. The specific system design includes a main control unit, a laser energy receiving unit, a drive power supply unit, a laser signal receiving unit, and a control drive unit. In specific implementation, the main control unit is designed to use ARM chips, DSP chips, FPGA chips, and PLC chips.

[0035] In applications, such as Figure 2 and Figure 3 As shown, the main control unit receives the detection current and detection voltage from the power semiconductor device, calculates and outputs the power supply signal and PWM control signal for the power semiconductor device, and then transmits them over a long distance to the laser energy receiving unit and the drive power supply unit via the energy laser beam and signal laser beam with the same direction and repetition frequency, respectively. The distance of the long-distance transmission depends on the laser signal power, as well as the transmission power and wavelength of the signal generator.

[0036] like Figure 2 and Figure 3 As shown, the laser energy receiving unit, based on the received laser beam, outputs corresponding electrical energy to the drive power supply unit via photoelectric conversion. The drive power supply unit then provides a reference voltage of 0V to the power semiconductor device and a supply voltage to the control drive unit based on the received electrical energy. The basic working principle is the photoelectric effect: when photons from the laser beam irradiate the surface of the semiconductor / metal material of the laser energy receiving unit, the energy is absorbed by electrons in the material, causing electrons to transition and generate free electrons. Typical laser energy receiving units include photovoltaic cells and high-power PIN photodiodes. Photovoltaic cells are specifically based on materials such as gallium arsenide and monocrystalline silicon. Photovoltaic cells can achieve an energy conversion efficiency of 30%-50% in the laser band and can use GaAs or silicon-based photovoltaic panels. PIN diodes have relatively lower conversion efficiency and are mainly used for optical / electrical signal conversion. In practical applications, the requirements for laser energy receiving units are high power and high conversion efficiency, while the requirements for their dynamic response speed are relatively lower.

[0037] like Figure 2 and Figure 3 As shown, the laser signal receiving unit obtains the PWM control signal for the power semiconductor device through photoelectric conversion based on the received laser beam, and outputs it to the control drive unit. The control drive unit amplifies the received PWM control signal based on the received power supply voltage, generates the corresponding drive control signal, and outputs it to the power semiconductor device to realize control.

[0038] According to the above design, laser signals are used as the medium for energy and signal transmission, thereby achieving complete electrical isolation between the primary and secondary sides and long-distance transmission.

[0039] Regarding the process of the main control unit outputting power supply signals and PWM control signals for power semiconductor devices to generate corresponding energy laser beams and signal laser beams, two specific implementation methods are designed in practical applications, such as... Figure 2 As shown, one embodiment employs a first laser emitter and a laser beam splitter. The main control unit receives the detection current and detection voltage from the power semiconductor device and calculates and generates an electrical signal, which is output to the first laser emitter. The electrical signal includes a power supply signal for the power semiconductor device and a PWM control signal. The first laser emitter generates a laser signal with the same direction and repetition frequency based on the received electrical signal and outputs it to the laser beam splitter. The laser beam splitter splits the received laser signal into two beams with different powers. The beam with higher power is the energy laser beam, and the beam with lower power is the signal laser beam, thus obtaining the energy laser beam and the signal laser beam for the power semiconductor device.

[0040] The core principle of laser beam splitters is to achieve energy splitting while maintaining laser coherence through amplitude division, wavefront division, or polarization selection. Different types of beam splitters correspond to different physical mechanisms and application scenarios. Common beam splitter types include dielectric mirrors, cubic beam splitters, and fiber beam splitters. Figure 5 As shown, taking a dielectric film reflector as an example, when a laser signal passes through the dielectric film, the interference effect between the multiple dielectric films can effectively control the reflection / transmission ratio, achieving low absorption loss and constant beam splitting ratio control, suitable for high-power laser transmission scenarios. The selection of the beam splitter first needs to consider isolating stray light from the signal beam. Since PWM electrical signals are sensitive to noise, the signal beam needs wavelength and polarization selection, and the propagation path needs to be shielded before the signal beam reaches the laser signal receiving unit. Secondly, the beam splitting ratio needs to be considered. The beam splitting ratio depends on the selected laser energy receiving unit and laser signal receiving unit. It is necessary to ensure that the laser signal receiving unit receives sufficient illumination for normal operation. In actual operation, at least a two-fold margin needs to be considered, leaving the remaining energy for the laser energy receiving unit.

[0041] In Example 1, signal and power transmission are achieved through a single laser signal, and power and signal are decomposed through a laser beam splitter, ultimately improving system integration and reducing costs.

[0042] like Figure 3As shown, in the two embodiments, a second laser emitter and a third laser emitter are used. The main control unit calculates and obtains the power supply signal and PWM control signal for the power semiconductor device, and outputs them to the second laser emitter and the third laser emitter, respectively. The second laser emitter generates an energy laser beam with the same direction and repetition frequency according to the received power supply signal and outputs it to the laser energy receiving unit. The third laser emitter generates a signal laser beam with the same direction and repetition frequency according to the received PWM control signal and outputs it to the laser signal receiving unit.

[0043] The selection of energy laser beams and signal laser beams—that is, specific lasers—requires comprehensive consideration of the application scenario. Common laser energy transmission wavelengths include 808nm, 1064nm, and 1550nm. The wavelength determines the absorption / scattering efficiency of the medium for the laser. For example, 1550nm infrared lasers attenuate less in the atmosphere than visible light, making them suitable for long-distance energy transmission; ultraviolet lasers are easily absorbed by atmospheric ozone, limiting their propagation distance. Furthermore, the selection of the laser also requires consideration of the selection of optical components. For instance, the wavelengths of the laser beam splitter, laser energy receiving unit, and laser signal receiving unit at the receiving end must be matched. The laser energy P... L and light intensity I L A comprehensive consideration is also necessary, primarily because laser energy transmission involves certain losses. Firstly, laser propagation in the medium suffers from scattering and other losses. Secondly, the optical-to-electrical conversion at the receiver also incurs losses. Defining the overall conversion efficiency as η, to ensure the receiver receives sufficient energy to drive the controlled device, the power or intensity of the laser generated at the transmitter needs to be designed to be higher. This ensures that after transmission and conversion losses, the gate drive still has enough power to drive the device. Furthermore, transmission delay needs to be considered. The process of converting the PWM electrical signal into laser light with the same repetition frequency at the laser transmitter introduces a certain delay, such as… Figure 6 T shown d1 There is a certain delay in the transmission of laser light from the transmitter to the receiver through a medium such as air. For example, it takes approximately 333 nanoseconds to transmit 100 meters in air or a vacuum. Simultaneously, there is also a delay in the optical-to-electrical signal conversion at the receiver. The sum of these two delays is as follows: Figure 6 T shown d2 As shown.

[0044] The above-mentioned design system is applied in practice, and specific designs are carried out for each important unit in the system. Among them, the design of the drive power supply unit includes a DC voltage regulator circuit, such as... Figure 7 As shown, the DC voltage regulator circuit includes a boost converter, a low dropout linear regulator (LDO), and a resistor R. D Zener diode Z DThe system includes two capacitors. The input terminal of the boost converter circuit forms the input terminal of the DC voltage regulator circuit, which is also the input terminal of the drive power supply unit. The output terminal of the boost converter circuit is connected to the input terminal of the low dropout linear regulator (LDO), and the positive output terminal of the LDO is connected to resistor R. D One end of one of the capacitors and one end of another are connected together, and the connection point forms the positive output terminal of the DC voltage regulator circuit, which is also the positive output terminal of the drive power supply unit, used to output the positive drive voltage V. dr_on To the control drive unit; the negative output terminal of the low dropout linear regulator (LDO); and the Zener diode Z. D The anode of one capacitor, one end of another capacitor, and the other two capacitors are connected together, and the connection point forms the negative output terminal of the DC voltage regulator circuit, which is also the negative output terminal of the drive power supply unit, used to output the negative drive voltage V. dr_off To the control drive unit; resistor R D The other end, Zener diode Z D The cathode, the other end of one capacitor, and the other end of another capacitor are connected together, and the connection point constitutes the reference voltage output terminal of the DC voltage regulator circuit, that is, the reference voltage output terminal of the drive power supply unit, which is used to output the reference voltage to the power semiconductor device.

[0045] Figure 7 In the application of the circuit structure shown, the laser energy receiving unit is directly connected to the battery for float charging, and the output voltage V is stabilized. dc1 V dc1 After simple amplification by the boost circuit, it is increased to V. dc2 V dc2 The voltage is stepped down to V by a low-dropout linear regulator (LDO). dc3 V dc3 Zener diode Z is connected to the output terminal. D and resistance R D Among them, the positive output of the low dropout linear regulator (LDO) is the positive drive voltage V. dr_on The output negative terminal is the negative drive voltage V. dr_off V dr_off The magnitude of the voltage is Z. D Zener voltage, R D and Z D The midpoint is connected to the reference potential and then to the source of the controlled device.

[0046] For different power semiconductor devices, V dr_on With V dr_off The values ​​are different; for example, commonly used 1.2kV power semiconductor devices such as MOSFETs and IGBTs have different values ​​(V). dr_on The value ranges from 15 to 20V. dr_offThe value ranges from 0 to -15V. The reference voltage of 0V is connected to the source terminal (S pole) of the power semiconductor device. For devices such as the Kelvin terminal (K pole), the reference voltage of 0V is connected to the Kelvin terminal.

[0047] Regarding the drive power supply unit, since the intensity of the laser signal varies with the PWM signal, and the PWM signal is generated by the main control unit, the transmission power during the process may be unstable. To prevent the PWM signal from being at a low level for a long time, i.e., the power required by the drive power supply unit is insufficient, a battery is further designed and introduced. The positive terminal of the battery is connected to the positive terminal of the DC voltage regulator circuit input, and the negative terminal of the battery is connected to the positive terminal of the DC voltage regulator circuit input.

[0048] In practical application according to the above design scheme, the laser energy receiving unit converts the received laser beam into DC voltage, which is then input into a three-terminal DC voltage regulator circuit. The DC voltage regulator circuit can convert the voltage into the voltage required for driving, and can take various forms, such as a low dropout linear regulator (LDO), a closed-loop switching power supply such as a buck chopper circuit or a boost chopper circuit. One end of the three-terminal DC voltage regulator circuit is connected to a battery. When the energy of the laser beam is insufficient, the battery can continuously supply power to the grid drive. Therefore, there are four power flow modes in this three-terminal DC voltage regulator circuit: (1) only the laser energy receiving unit supplies power to the drive unit, and the battery does not charge or discharge; (2) both the laser energy receiving unit and the battery supply power to the drive unit at the same time, and the battery is in a discharging state; (3) the laser energy receiving unit does not supply power, and only the battery supplies power to the drive unit; (4) the drive unit consumes no energy, the laser energy receiving unit supplies power to the battery, and the battery is charged.

[0049] Regarding the laser signal receiving unit, the system designed in this invention has low requirements for the energy conversion efficiency and power of the laser signal receiving unit, but high requirements for the dynamic response speed of the laser signal receiving unit, requiring the achievement of relatively higher output voltage rise / fall edges. Therefore, in practical applications, such as Figure 8 As shown, the specific design includes photodiode D. PIN ,inductance ,capacitance Operational amplifier OP1, comparator CMP, and photodiode D PIN The photosensitive end constitutes the input end of the laser signal receiving unit, used to receive the signal laser beam. In practical applications, to prevent interference from stray light, it is necessary to shield the laser signal receiving unit from stray light. An ambient light shielding layer can be used between the laser beam splitter and the laser signal receiving unit, meaning the signal laser beam passes through the ambient light shielding layer before being directed to the input end of the laser signal receiving unit; photodiode D PIN negative electrode, capacitor One end of the inductor One end of the capacitor, the inverting input of operational amplifier OP1, and the capacitor are connected together. The other end, inductor The other end, the output of operational amplifier OP1, and the positive input of comparator CMP are connected together. The output of comparator CMP constitutes the output of the laser signal receiving unit, used to output the PWM control signal for power semiconductor devices. The positive power supply terminals of operational amplifier OP1 and comparator CMP are respectively connected to external voltages. Photodiode D PIN The positive terminal of the DC-DC converter, the positive input terminal of operational amplifier OP1, the negative power supply terminal of operational amplifier OP1, and the negative power supply terminal of comparator CMP are all connected to the negative drive voltage output by the DC-DC regulator circuit. The inverting input terminal of comparator CMP is connected to a preset reference voltage. .

[0050] The control drive unit is specifically designed with a PMOS transistor, an NMOS transistor, and an inverter. The input of the inverter forms the input of the control drive unit, receiving the PWM control signal output from the laser signal receiving unit. The gates of the PMOS and NMOS transistors, and the output of the inverter are connected together. The source of the PMOS transistor is connected to the positive drive voltage from the power supply voltage output by the drive power supply unit. The drains of the PMOS and NMOS transistors are connected, and this connection point forms the output of the control drive unit. A drive resistor is connected in series with the output of the control drive unit. Then, it connects to the power semiconductor device to output drive control electrical signals to the power semiconductor device. The source of the NMOS transistor is connected to the negative drive voltage in the power supply voltage output by the drive power supply unit.

[0051] The above Figure 8 The designed laser signal receiving unit, combined with the specifically designed control and drive unit, in practical applications, when the photodiode D... PIN After receiving the signal laser beam, a photocurrent I is induced. D The operational amplifier OP1 has a high input impedance, therefore the photocurrent I... D Current flowing through the inductor And generate a voltage, at which point the operational amplifier OP1 outputs a voltage V. D for

[0052] ;

[0053] Voltage V D Continue connecting to the positive input terminal of comparator CMP, and connect the preset reference voltage to the inverting input terminal of comparator CMP. When V D Greater than V ref At that time, the comparator CMP outputs VCMP A high level indicates a high level, otherwise the output is V. CMP The level is low. V CMP The signal is then transmitted to the control drive unit, whose main function is to amplify the signal. This amplification can be achieved using CMOS circuits or CBJT circuits, and its output voltage V... dr Obtain as follows;

[0054] ;

[0055] Control drive unit output voltage V dr After the driving resistor It is connected to the gate of a power semiconductor device to control the switching on and off of the power semiconductor device.

[0056] The battery design here ensures that the drive power supply unit can still be powered when the PWM signal is low or the LL signal is briefly blocked, effectively guaranteeing the reliability of power transmission.

[0057] In practical applications, with Figure 4 Taking the motor drive shown as an example, the main control unit in the transmitter is the system's local control unit, typically an ARM, DSP, FPGA, or PLC. Its main function is to receive feedback information from the converter, such as output voltage and current, calculate the control algorithm, and output PWM signals to the gates of each device to control their on / off states, thereby adjusting the motor drive output. For this application, such as... Figure 2 As shown, the design scheme of this invention transmits the PWM electrical signal to the first laser transmitter, where it is converted into a laser signal with the same direction and repetition frequency. It should be noted that there is a certain transmission delay in the electro-optical conversion process.

[0058] This invention describes the process of generating corresponding energy laser beams and signal laser beams by outputting power supply signals and PWM control signals from the main control unit. Two embodiments are provided: Embodiment 1 and Embodiment 2. Compared to Embodiment 1, Embodiment 2 requires two laser beams. Its advantage lies in the fact that the energy laser beam is continuously high-level, providing continuous energy to the drive power supply unit. This reduces the battery capacity, and in cases where stable transmission of the energy laser beam can be guaranteed, the battery can be eliminated. Furthermore, no laser beam splitter is required. Therefore, Embodiment 2 has a cost advantage over Embodiment 1.

[0059] like Figure 2 As shown, the theoretical effect ultimately achieved by the system designed in this invention is as follows: Figure 6 The waveform shown illustrates that the PWM signal at the transmitting end is generated by the main control unit, converted into a laser signal by the laser transmitter, and then restored to a PWM electrical signal by the receiving end after receiving the laser signal. Simultaneously, the control and drive unit amplifies this signal into a drive output voltage V. dr Vdr After the driving resistor When the gate of a power semiconductor device is connected, the gate-source voltage V of the power semiconductor device is... gs Waveform as Figure 6 The diagram shows the transient processes of activation and deactivation. During activation, V... gs Rise to V dr,on Drain-source voltage V of power semiconductor device ds When the voltage drops to the on-state, the drain-source current I ds As the current rises to the load current level, the power semiconductor device eventually turns on fully. Conversely, when it turns off, V... gs Descending to V dr,off Drain-source voltage V ds Rising to DC bus voltage, drain-source current I ds As the voltage drops to near zero, the power semiconductor device eventually shuts off.

[0060] Applying the system designed in this invention to, for example Figure 9 In the third embodiment shown, photodiode D PIN When illuminated by a signal laser beam, the photodiode D is in a conducting state and in a cut-off state when the illumination disappears. PIN Consider it as an output current at 0A and a photocurrent I D A rapidly changing pulsed current source I1. Photogenerated current I. D The current is relatively small, therefore the pulse current source I1 is set to switch between 0A and 20μA, with a switching frequency of 10kHz and a duty cycle of 0.5, as shown in the waveform. Figure 10 As shown in Figure I(l1), the operational amplifier OP1, comparator CMP, and drive power supply are powered by two linear regulators, LT3015 and LT3045, respectively. When the pulse current source I1 jumps to 20uA, the operational amplifier OP1 outputs a high level, and the level is equal to... When the pulse current source I1 jumps to 0A, the operational amplifier OP1 outputs a high level, and the output waveform of OP1 is as follows. Figure 10 As shown in V(op1). The output of OP1 is connected to comparator CMP, which compares the output level of OP1 with V. ref Comparison, when the output level of OP1 is higher than V ref The comparator CMP outputs a high level V. cmp Conversely, V cmp When the output is low, the CMP output waveform is as follows: Figure 10The value of V(cmp) is shown in the diagram. The selected comparator model is LT1794. It is important to note that the input signal to the comparator CMP must be within its supply voltage range. The output signal of the comparator CMP enters the drive unit composed of a CMOS push-pull circuit, where the drive signal is amplified and then passes through the drive resistor R4 to reach the gate of the power device, achieving the function of turning the device on and off. The gate voltage, drain current, and drain-source voltage of the power device are shown in the diagram. Figure 10 The values ​​V(vgs), Ix(U4:D), and V(vd) are shown in the figure.

[0061] This invention presents a power semiconductor device driving system based on laser transmission. It uses laser signals as the transmission medium to achieve long-distance transmission of signals and energy, and has extremely strong electromagnetic noise suppression capabilities. Compared with traditional drives, the laser signal transmission process is no longer affected by environmental electromagnetic noise interference, making it applicable to complex electromagnetic noise environments. It can also achieve a high isolation voltage level, making it effective for high-voltage applications. Furthermore, it achieves electrical isolation between the power end and the signal generation end of the converter, reducing the common-mode noise transmitted from the local end of the device to the remote end to zero, effectively improving the operational safety of the system. It can be effectively applied to scenarios such as mining, oil exploration, and high-voltage power grid operations.

[0062] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A power semiconductor device driving system based on laser transmission, characterized in that: It includes a main control unit, a laser energy receiving unit, a drive power supply unit, a laser signal receiving unit, and a control drive unit. The main control unit receives the detection current and detection voltage from the power semiconductor device, calculates and outputs the power supply signal and control signal for the power semiconductor device, and then sends them to the laser energy receiving unit and the drive power supply unit through the energy laser beam and the signal laser beam with the same direction and repetition frequency, respectively. The laser energy receiving unit, based on the received laser beam, outputs corresponding electrical energy to the drive power supply unit via photoelectric conversion. The drive power supply unit, based on the received electrical energy, provides a reference voltage to the power semiconductor device and a power supply voltage to the control drive unit. The laser signal receiving unit obtains the control electrical signal for the power semiconductor device through photoelectric conversion based on the received laser signal beam, and outputs it to the control drive unit. The control drive unit generates a drive control electrical signal corresponding to the received control electrical signal based on the received power supply voltage, and outputs it to the power semiconductor device to realize control.

2. The power semiconductor device driving system based on laser transmission according to claim 1, characterized in that: It also includes a first laser emitter and a laser beam splitter. The main control unit receives the detection current and detection voltage from the power semiconductor device and calculates and generates an electrical signal, which is output to the first laser emitter. The electrical signal includes a power supply signal and a control signal for the power semiconductor device. The first laser emitter generates a laser signal with the same direction and repetition frequency based on the received electrical signal and outputs it to the laser beam splitter. The laser beam splitter splits the received laser signal into two beams to obtain an energy laser beam and a signal laser beam for the power semiconductor device.

3. The power semiconductor device driving system based on laser transmission according to claim 1, characterized in that: It also includes a second laser emitter and a third laser emitter. The main control unit calculates and obtains the power supply signal and control signal for the power semiconductor device, and outputs them to the second laser emitter and the third laser emitter respectively. The second laser emitter generates an energy laser beam with the same direction and repetition frequency according to the received power supply signal and outputs it to the laser energy receiving unit. The third laser emitter generates a signal laser beam with the same direction and repetition frequency according to the received control signal and outputs it to the laser signal receiving unit.

4. A power semiconductor device driving system based on laser transmission according to any one of claims 1 to 3, characterized in that: The drive power supply unit includes a DC voltage regulator circuit, which includes a boost circuit, a low dropout linear regulator (LDO), and a resistor R. D Zener diode Z D The system includes two capacitors. The input terminal of the boost converter circuit forms the input terminal of the DC voltage regulator circuit, which is also the input terminal of the drive power supply unit. The output terminal of the boost converter circuit is connected to the input terminal of the low dropout linear regulator (LDO), and the positive output terminal of the LDO is connected to resistor R. D One end of one of the capacitors and one end of another are connected together, and the connection point forms the positive output terminal of the DC voltage regulator circuit, which is also the positive output terminal of the drive power supply unit, used to output the positive drive voltage V. dr_on To the control drive unit; the negative output terminal of the low dropout linear regulator (LDO); and the Zener diode Z. D The anode of one capacitor, one end of another capacitor, and the other two capacitors are connected together, and the connection point forms the negative output terminal of the DC voltage regulator circuit, which is also the negative output terminal of the drive power supply unit, used to output the negative drive voltage V. dr_off To the control drive unit; resistor R D The other end, Zener diode Z D The cathode, the other end of one capacitor, and the other end of another capacitor are connected together, and the connection point constitutes the reference voltage output terminal of the DC voltage regulator circuit, that is, the reference voltage output terminal of the drive power supply unit, which is used to output the reference voltage to the power semiconductor device.

5. The power semiconductor device driving system based on laser transmission according to claim 4, characterized in that: The drive power supply unit also includes a battery, with the positive terminal of the battery connected to the positive terminal of the DC voltage regulator circuit input and the negative terminal of the battery connected to the positive terminal of the DC voltage regulator circuit input.

6. The power semiconductor device driving system based on laser transmission according to claim 4, characterized in that: The laser signal receiving unit includes a photodiode D. PIN ,inductance ,capacitance Operational amplifier OP1, comparator CMP, and photodiode D PIN The photosensitive end forms the input end of the laser signal receiving unit, used to receive the signal laser beam; photodiode D PIN negative electrode, capacitor One end of the inductor One end of the capacitor, the inverting input of operational amplifier OP1, and the capacitor are connected together. The other end, inductor The other end, the output of operational amplifier OP1, and the positive input of comparator CMP are connected together. The output of comparator CMP constitutes the output of the laser signal receiving unit, used to output control electrical signals for power semiconductor devices. The positive power supply terminals of operational amplifier OP1 and comparator CMP are respectively connected to external voltages. Photodiode D PIN The positive terminal of the DC-DC converter, the positive input terminal of operational amplifier OP1, the negative power supply terminal of operational amplifier OP1, and the negative power supply terminal of comparator CMP are all connected to the negative drive voltage output by the DC-DC regulator circuit. The inverting input terminal of comparator CMP is connected to a preset reference voltage. .

7. The power semiconductor device driving system based on laser transmission according to claim 4, characterized in that: The control drive unit includes a PMOS transistor, an NMOS transistor, and an inverter. The input terminal of the inverter forms the input terminal of the control drive unit, used to receive the control electrical signal output by the laser signal receiving unit. The gates of the PMOS transistor, the NMOS transistor, and the output terminal of the inverter are connected together. The source of the PMOS transistor is connected to the positive drive voltage in the power supply voltage output by the drive power supply unit. The drains of the PMOS transistor and the drains of the NMOS transistor are connected, and the connection position forms the output terminal of the control drive unit, used to output the drive control electrical signal to the power semiconductor device. The source of the NMOS transistor is connected to the negative drive voltage in the power supply voltage output by the drive power supply unit.

8. The power semiconductor device driving system based on laser transmission according to claim 7, characterized in that: The output terminal of the control drive unit is connected in series with a drive resistor. Then, docking with power semiconductor devices.

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