Isolation power coupling module for highway domain photovoltaic grid-connected power generation device

Abstract

The application discloses a high-speed road area photovoltaic grid-connected power generation device isolation power coupling module, which comprises a photovoltaic side bridge arm, a first switch tube and a second switch tube; a second power switch node is arranged between the first switch tube and the second switch tube, the drain electrode of the first switch tube is connected to a photovoltaic side power supply, and the source electrode of the second switch tube is grounded; a grid-connected side bridge arm for connecting a grid-connected side power supply, a third switch tube and a fourth switch tube; a first power switch node is arranged between the source electrode of the third switch tube and the drain electrode of the fourth switch tube; the drain electrode of the third switch tube is connected to the photovoltaic side power supply, and the source electrode of the fourth switch tube is grounded; and a coupling inductor, two ends of the coupling inductor are respectively connected to the first power switch node and the second power switch node. The application is suitable for the case that one end of a high-speed road is a photovoltaic array and the other end is a station direct-current bus / energy storage through the arrangement of symmetrical photovoltaic side bridge arms and grid-connected side bridge arms and the connection of a single coupling inductor.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic power generation, and more specifically to an isolated power coupling module for a grid-connected photovoltaic power generation device in high-speed road areas. Background Technology

[0002] As an important component of distributed energy utilization, highway photovoltaic (PV) power generation systems have been widely applied in highway construction both domestically and internationally in recent years. These systems typically include PV arrays distributed along the highway, nearby grid-connected devices, and optional energy storage equipment, aiming to fully utilize underutilized land resources on both sides of the highway and achieve on-site production and consumption of green energy. In PV grid-connected systems, the power coupling module serves as the interface between the PV side and the grid / energy storage side; its performance directly determines the efficiency, reliability, and security of the entire system.

[0003] Currently, the power coupling in photovoltaic grid-connected power generation systems along highways mainly involves the following technical solutions: The first type is the unidirectional boost converter power coupling scheme. This scheme uses a simple boost converter structure to boost the low-voltage DC from the photovoltaic side and then transmit it to the grid-connected inverter. Its characteristics include a simple structure, containing only one inductor, one switching transistor, and one rectifier diode. However, this scheme can only transfer energy in one direction, from the photovoltaic side to the grid-connected side, and cannot provide pre-charging or sustaining voltage for the photovoltaic system when sunlight is insufficient. Furthermore, due to the lack of a symmetrical structural design, its switching waveform is not balanced, making it prone to significant electromagnetic interference, especially in complex electromagnetic environments such as highways.

[0004] The second type is the bidirectional DC-DC converter solution with an isolation transformer. This type of solution achieves electrical isolation between the photovoltaic side and the grid-connected side through a high-frequency transformer, which can effectively solve safety issues, especially in high-voltage grid-connected systems. However, the isolation transformer increases size, weight, and cost, and reduces power density. At the same time, the parasitic oscillation problem caused by the transformer's leakage inductance and distributed capacitance is more pronounced in outdoor environments such as highways, and is easily affected by environmental factors such as temperature and humidity, reducing system reliability.

[0005] The third type is the non-isolated bidirectional Buck-Boost converter solution. This solution has a relatively simple structure, requires no isolation transformer, and can achieve bidirectional energy transfer. However, traditional non-isolated bidirectional Buck-Boost converters typically employ an asymmetrical design, with one side being an active switch and the other a synchronous rectifier. This asymmetrical structure is inefficient in scenarios like highways where frequent bidirectional energy flow is required, especially when lighting conditions change frequently, resulting in slow system response and difficulty in effectively achieving maximum power point tracking (MPPT).

[0006] The above solutions generally suffer from the following technical problems in practical applications of photovoltaic grid connection along highways: Poor electromagnetic compatibility: Highway environments contain numerous interference sources, such as vehicle electronic equipment and communication systems. Traditional power coupling modules lack effective EMI suppression measures and are easily affected or generate interference in long cables and harsh electromagnetic environments, impacting system stability and reliability.

[0007] Low current detection accuracy: Existing solutions typically only set up current detection on one side, which cannot simultaneously and accurately monitor the power status of the photovoltaic side and the grid-connected side, making it difficult to achieve accurate power balance control and fault detection.

[0008] Low energy efficiency: Unidirectional energy transfer schemes cannot fully utilize the energy on the grid-connected side and the energy storage side to maintain the stable operation of the photovoltaic system under low illumination conditions; while asymmetrical bidirectional structures suffer greater efficiency loss in scenarios with frequent bidirectional energy flow.

[0009] Insufficient security: The lack of effective bidirectional current control and monitoring means that it is difficult to achieve fast and safe anti-islanding protection when the grid-connected system experiences grid faults or power outages, posing a safety hazard.

[0010] Poor drive reliability: The unreasonable layout of the high-side drive circuit can easily lead to drive instability in environments with long cables on highways and high electromagnetic interference, affecting system reliability.

[0011] Therefore, there is an urgent need for an isolated power coupling module specifically designed for grid-connected photovoltaic power generation along highways, which can simultaneously achieve high efficiency, high reliability, low EMI interference, and safety protection, and meet the requirements of the special application environment of highways. Summary of the Invention

[0012] This invention discloses an isolated power coupling module for a high-speed road photovoltaic grid-connected power generation device, installed between the photovoltaic-side power source (VIN) and the grid-connected power source (VBUS), comprising: A photovoltaic-side bridge arm for connecting a photovoltaic power source (VIN) includes a first switch (U4) and a second switch (U6); a second power switch node (LX2) is provided between the drain of the first switch (U4) and the source of the second switch (U6); the source of the first switch (U4) is connected to the photovoltaic power source (VIN), and the drain of the second switch (U6) is grounded. The grid-connected bridge arm for connecting the grid-connected power supply (VBUS) includes a third switch (U5) and a fourth switch (U7), forming a half-bridge symmetrical to the photovoltaic bridge arm; a first power switching node (LX1) is provided between the drain of the third switch (U5) and the source of the fourth switch (U7); the source of the third switch (U5) is connected to the grid-connected power supply (VBUS), and the drain of the fourth switch (U7) is grounded; A coupling inductor (L1) is used to realize bidirectional energy transfer between the photovoltaic side and the grid-connected side. The two ends of the coupling inductor (L1) are connected to the first power switching node (LX1) and the second power switching node (LX2), respectively.

[0013] A further improvement of the present invention is that the power coupling module further includes: A photovoltaic-side current detection circuit includes a first shunt resistor (R1), a photovoltaic-side high-frequency bypass capacitor (C5), and a photovoltaic-side current limiting resistor (R4). The first shunt resistor (R1) is connected in series between the photovoltaic-side power supply (VIN) and the first switching transistor (U4). The photovoltaic-side high-frequency bypass capacitor (C5) and the photovoltaic-side current limiting resistor (R4) are connected in series and in parallel with the first shunt resistor (R1). A photovoltaic-side current sampling pin (CSN2) for detecting the photovoltaic-side current is provided between the photovoltaic-side high-frequency bypass capacitor (C5) and the photovoltaic-side current limiting resistor (R4). The grid-connected current detection circuit includes a second shunt resistor (R2), a grid-connected high-frequency bypass capacitor (C6), and a grid-connected current limiting resistor (R5). The second shunt resistor (R2) is connected in series between the grid-connected power supply (VBUS) and the third switching transistor (U5). The grid-connected high-frequency bypass capacitor (C6) and the grid-connected current limiting resistor (R5) are connected in series and in parallel with the second shunt resistor (R2). A grid-connected current sampling pin (CSP1) for detecting the grid-connected current is provided between the grid-connected high-frequency bypass capacitor (C6) and the grid-connected current limiting resistor (R5).

[0014] A further improvement of the present invention is that the resistance values ​​of the first shunt resistor (R1) and the second shunt resistor (R2) are the same.

[0015] A further improvement of the present invention is that it further includes a first bootstrap pin (BST1) and a second bootstrap pin (BST2), wherein the second bootstrap pin (BST2) is disposed between the second power switch node (LX2) and the coupled inductor (L1), and the first bootstrap pin (BST1) is disposed between the first power switch node (LX1) and the coupled inductor (L1). It also includes a photovoltaic-side bootstrap circuit, which includes a first switching transistor (U4) as a bootstrap diode and a photovoltaic-side bootstrap capacitor (C7), which is connected across the second bootstrap pin (BST2) and the photovoltaic-side power switching node (LX2). It also includes a grid-connected bootstrap circuit, which includes the third switch (U5) as a bootstrap diode and a grid-connected bootstrap capacitor (C8), which is connected across the second bootstrap pin (BST2) and the grid-connected power switch node (LX1).

[0016] A further improvement of the present invention is that it further includes: A photovoltaic-side RC absorption network is connected between the end of the coupled inductor (L1) closest to the photovoltaic-side bridge arm and ground; The grid-connected RC absorption network is connected between the end of the coupled inductor (L1) near the grid-connected bridge arm and ground.

[0017] A further improvement of the present invention is that the photovoltaic-side RC absorption network and the grid-connected side RC absorption network have the same resistance and capacitance values, forming a symmetrical structure.

[0018] This invention discloses an isolated power coupling module for a high-speed roadside photovoltaic grid-connected power generation device. By setting up symmetrical photovoltaic side bridge arms and grid-connected side bridge arms, and connecting the two symmetrical bridge arms through a single coupling inductor (L1), this symmetrical structure allows a single power board to handle both photovoltaic side operating point tracking (MPPT) and grid-connected side bus stability / energy storage management. It is suitable for situations where one end of the highway is a photovoltaic array and the other end is an in-station DC bus / energy storage. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the circuit structure of the present invention; Detailed Implementation

[0020] This invention discloses an isolated power coupling module for a high-speed road photovoltaic grid-connected power generation device, installed between the photovoltaic-side power supply VIN and the grid-connected power supply VBUS, comprising: A photovoltaic-side bridge arm for connecting to the photovoltaic-side power supply VIN includes a first switch U4 and a second switch U6; a second power switch node LX2 is provided between the source of the first switch U4 and the drain of the second switch U6, the drain of the first switch U4 is connected to the photovoltaic-side power supply VIN, and the source of the second switch U6 is grounded. The grid-connected bridge arm for connecting the grid-connected power supply VBUS includes a third switch U5 and a fourth switch U7, forming a half-bridge symmetrical to the photovoltaic bridge arm; a first power switch node LX1 is provided between the source of the third switch U5 and the drain of the fourth switch U7; the drain of the third switch U5 is connected to the photovoltaic power supply VIN, and the source of the fourth switch U7 is grounded; The coupling inductor L1 is used to realize bidirectional energy transfer between the photovoltaic side and the grid-connected side. The two ends of the coupling inductor L1 are connected to the first power switch node LX1 and the second power switch node LX2, respectively.

[0021] This invention employs a symmetrical dual-bridge + single-inductor structure: symmetrically designed photovoltaic-side bridge arms and grid-connected-side bridge arms, with bidirectional energy transfer achieved through a central coupling inductor L1. This symmetrical structure allows a single power board to handle both photovoltaic-side MPPT (MPT) tracking and grid-connected-side bus stability / energy storage management, making it suitable for situations where one end of a highway is a photovoltaic array and the other end is an in-station DC bus / energy storage system.

[0022] like Figure 1 As shown, the gate of the first switching transistor U4 is connected to pin HG1, the gate of the second switching transistor U6 is connected to pin LG2, the gate of the third switching transistor U5 is connected to pin HG2, and the gate of the fourth switching transistor U7 is connected to pin LG1. Pins HG1, LG2, HG2, and LG1 are all connected to PWM to control the opening and closing of the above switching transistors, thereby controlling the entire half-bridge.

[0023] like Figure 1 As shown, it also includes: A photovoltaic-side current detection circuit includes a first shunt resistor R1, a photovoltaic-side high-frequency bypass capacitor C5, and a photovoltaic-side current limiting resistor R4. The first shunt resistor R1 is connected in series between the photovoltaic-side power supply VIN and the first switching transistor U4. The photovoltaic-side high-frequency bypass capacitor C5 and the photovoltaic-side current limiting resistor R4 are connected in series and in parallel with the first shunt resistor R1. A photovoltaic-side current sampling pin CSN2 for detecting the photovoltaic-side current is provided between the photovoltaic-side high-frequency bypass capacitor C5 and the photovoltaic-side current limiting resistor R4. The grid-connected current detection circuit includes a second shunt resistor R2, a grid-connected high-frequency bypass capacitor C6, and a grid-connected current limiting resistor R5. The second shunt resistor R2 is connected in series between the grid-connected power supply VBUS and the third switching transistor U5. The grid-connected high-frequency bypass capacitor C6 and the grid-connected current limiting resistor R5 are connected in series and in parallel with the second shunt resistor R2. A grid-connected current sampling pin CSP1 for detecting the grid-connected current is provided between the grid-connected high-frequency bypass capacitor C6 and the grid-connected current limiting resistor R5.

[0024] This invention features a dual-end precision current sensing architecture. Precise first shunt resistors R1 and second shunt resistors R2 are respectively installed on the photovoltaic (PV) side and the grid-connected side. These, along with the PV-side high-frequency bypass capacitor C5 and the grid-connected side high-frequency bypass capacitor C6, as well as the PV-side current limiting resistor R4 and the grid-connected side current limiting resistor R5, form a complete sampling link. This dual-end sensing structure allows the controller to simultaneously monitor how much power is drawn from the PV side and how much is transmitted from the grid side, achieving precise power balance control.

[0025] This invention achieves a highly efficient safety protection strategy through bidirectional current detection and enable signal sharing. When an abnormal voltage is detected on the grid-connected side, the controller can immediately shut down both bridge arms, rapidly reducing the inductor current to a safe value. Simultaneously, the dual-authorization structure with shared enable signals ensures coordinated operation of both bridge arms, avoiding shoot-through risks caused by asynchronous control and further enhancing system safety.

[0026] Preferably, the first shunt resistor R1 and the second shunt resistor R2 have the same resistance value. In this embodiment, both the first shunt resistor R1 and the second shunt resistor R2 are 5MΩ, so that the circuits on both sides are completely symmetrical.

[0027] Better, such as Figure 1 As shown, in this embodiment, it also includes: A photovoltaic-side RC absorption network is connected between the end of the coupling inductor L1 closest to the photovoltaic-side bridge arm and ground. The grid-connected RC absorption network is connected between the end of the coupled inductor L1 near the grid-connected bridge arm and ground. Better, such as Figure 1 As shown, the photovoltaic-side RC absorption network includes a resistor R6 and a capacitor C15, and the grid-connected RC absorption network includes a resistor R7 and a capacitor C16. R6 and R7 have the same resistance value, and C15 and C16 have the same capacitance value, forming a symmetrical structure. In this embodiment, the resistance values ​​of R6 and R7 are both 2Ω, and the capacitance values ​​of C15 and C16 are both 3.3nF. By forming a symmetrical structure, switching overshoot and ringing can be suppressed, and EMI interference can be reduced.

[0028] This invention sets up RC absorption networks R6, C15, R7, and C16 with completely symmetrical structures at both ends of the coupled inductor L1. This design effectively absorbs switching overshoot and ringing caused by inductor leakage inductance and distributed capacitance. For practical applications involving cables tens of meters long along highways, this not only reduces external EMI radiation and protects surrounding equipment, but also protects the MOSFETs inside the module from overvoltage damage, thus improving the overall system lifespan.

[0029] Better, such as Figure 1 As shown, it also includes The first bootstrap pin BST1 and the second bootstrap pin BST2 are located between the second power switch node LX2 and the coupling inductor L1, and the first bootstrap pin BST1 is located between the first power switch node LX1 and the coupling inductor L1. It also includes a photovoltaic-side bootstrap circuit, which includes a first switching transistor U4 as a bootstrap diode and a photovoltaic-side bootstrap capacitor C7, wherein the bootstrap capacitor C7 is connected across the second bootstrap pin BST2 and the photovoltaic-side power switching node LX2. It also includes a grid-connected bootstrap circuit, which includes the third switch U5 as a bootstrap diode and a grid-connected bootstrap capacitor C8. The grid-connected bootstrap capacitor C8 is directly connected between the second bootstrap pin BST2 and the grid-connected power switch node LX1.

[0030] This invention achieves a high-speed bootstrap drive layout design through photovoltaic-side bootstrap circuit and grid-connected-side bootstrap circuit: The photovoltaic-side bootstrap capacitor C7 and the grid-connected-side bootstrap capacitor C8 are directly connected between the second / first bootstrap pin BST2 / BST1 and the second / first power switch node LX2 / LX1, with extremely short traces, which significantly reduces the parasitic inductance of the high-side drive.

[0031] The working process of this invention is as follows: When the photovoltaic (PV) power supply VIN has sufficient energy to be transferred to the grid-connected power supply VBUS, the PV-side bridge arm operates in boost / push mode, and the PV-side power switching node LX2 generates a PWM square wave. The coupling inductor L1 obtains chopping energy and sends current to the grid-connected side. The grid-connected bridge arm operates in synchronous rectification mode, and the third switch HG1 and the fourth switch LG1 operate in a timing sequence that is complementary to or phase-shifted with the PV side, smoothly connecting the inductor current to the grid-connected power supply VBUS. The current of the first shunt resistor R1 is fed back to the controller for MPPT tracking; the current of the second shunt resistor R2 is fed back to the controller for grid-connected side current limiting / bus overcurrent protection.

[0032] When energy needs to be transferred from the grid-connected side to the photovoltaic side, such as in the morning or under the shade to precharge photovoltaic panels, the controller only needs to set the grid-connected side bridge arm as the "chopper end" and the photovoltaic side bridge arm as the "rectifier end". The current in the coupling inductor L1 can then flow in reverse, realizing reverse energy transfer. Since there are precision shunt resistors at both ends, the reverse power can also be accurately measured, which is convenient for energy statistics and preventing false reverse transmission.

[0033] Throughout the operation, the photovoltaic-side RC absorption network and the grid-connected side RC absorption network operate continuously, absorbing spikes and ringing generated during bridge arm switching, suppressing EMI interference, and protecting the MOSFETs from overvoltage damage. The photovoltaic-side bootstrap capacitor C7 and the grid-side bootstrap capacitor C8 are positioned close to the power switching node to ensure the reliability of the high-side drive. The photovoltaic-side high-frequency bypass capacitor C5 and the grid-side high-frequency bypass capacitor C6 filter the current sensing signal, providing a clean sampling signal to the controller.

[0034] When an anomaly is detected on the grid-connected side, such as a power outage, the controller can immediately shut down both ends of the bridge arm through a shared enable signal, rapidly attenuating the current of the coupled inductor L1 to a safe value, thereby achieving anti-islanding protection and ensuring system safety.

[0035] In summary, this invention achieves efficient bidirectional energy transfer through a symmetrical dual-bridge, single-inductor structural design; realizes power balance and fault location through precise dual-end current detection; improves drive reliability through a high-speed bootstrap drive layout; effectively suppresses EMI interference through a symmetrical RC absorption network; and achieves reliable anti-islanding protection through a dual-authorization security chain sharing the enable signal. It is suitable for long-cable, complex electromagnetic environments such as high-speed road photovoltaic grid-connected power generation, significantly improving system efficiency, stability, and security.

[0036] This application verifies the technical effectiveness of the isolated power coupling module for photovoltaic grid-connected power generation devices in high-speed road areas through the following experiments.

[0037] Through comparative testing, the prototype of this invention was directly compared with a traditional asymmetric bidirectional Buck-Boost converter, and measurements were performed using a laboratory power analyzer, oscilloscope, EMI testing equipment, and environmental simulation device.

[0038] Technical Effect Comparison Table Energy conversion efficiency in bidirectional flow scenarios 82% 90% Increase by 8% The symmetrical dual-bridge structure reduces conduction losses, especially improving efficiency by more than 15% under low duty cycle conditions. Power control accuracy ±5% ±1% Increase by 80% Dual-end precise current detection significantly improves the accuracy of power balance control, adapting to power grid fluctuation scenarios. MOSFET turn-on time 85ns 51ns shorten by 40% The compact layout of the bootstrap capacitor reduces parasitic inductance and reduces turn-on losses by approximately 35%. Switch node ringing amplitude 100% 30% Reduced by 70% The symmetrical RC absorption network effectively suppresses ringing, reduces overshoot voltage by about 50%, and reduces radiated EMI by about 15dB. Anti-islanding response time 120ms 42ms shorten by 65% The bidirectional current detection and enable signal sharing design makes the anti-islanding response time far superior to the national standard requirements. Energy efficiency verification: Set the photovoltaic side input voltage to three levels: 36V, 48V, and 60V; measure the forward and reverse energy transfer efficiency at 25%, 50%, 75%, and 100% of the rated power; use a Yokogawa WT5000 power analyzer to monitor the input / output power simultaneously; EMI suppression verification: A 50-meter cable was used to simulate a real-world highway application scenario; waveforms at LX1 / LX2 nodes were recorded with and without RC absorption networks; radiation in the 10kHz-30MHz frequency band was measured in a radiated EMI anechoic chamber.

[0039] Drive performance verification: The rise of the bootstrap capacitor drive waveform was measured using a high-precision oscilloscope; the turn-on delay time of the high-side MOSFETs on the photovoltaic side and the grid-connected side was compared; and the switching losses were recorded at frequencies of 100kHz / 200kHz / 300kHz.

[0040] Anti-islanding response test: Simulate a power outage scenario and observe the islanding detection time; measure the time required from detecting an anomaly to safe shutdown; compare the response speed of the present invention with that of traditional solutions under different load conditions.

[0041] Verification conclusion: This invention is significantly superior to existing technologies. Specifically, it improves energy conversion efficiency by 8%, power control accuracy by 80%, turn-on time by 40%, ringing amplitude by 70%, and anti-islanding response time by 65%, demonstrating broad application prospects.

[0042] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A power coupling module for a high-speed road photovoltaic grid-connected power generation device, installed between the photovoltaic-side power supply (VIN) and the grid-connected power supply (VBUS), characterized in that, include: A photovoltaic-side bridge arm for connecting a photovoltaic power source (VIN) includes a first switch (U4) and a second switch (U6); a second power switch node (LX2) is provided between the drain of the first switch (U4) and the source of the second switch (U6); the source of the first switch (U4) is connected to the photovoltaic power source (VIN), and the drain of the second switch (U6) is grounded. The grid-connected bridge arm for connecting to the grid-connected power supply (VBUS) includes a third switch (U5) and a fourth switch (U7), forming a half-bridge symmetrical to the photovoltaic bridge arm; a first power switching node (LX1) is provided between the drain of the third switch (U5) and the source of the fourth switch (U7); the source of the third switch (U5) is connected to the grid-connected power supply (VBUS), and the drain of the fourth switch (U7) is grounded; A coupling inductor (L1) is used to realize bidirectional energy transfer between the photovoltaic side and the grid-connected side. The two ends of the coupling inductor (L1) are connected to the first power switching node (LX1) and the second power switching node (LX2), respectively.

2. The isolated power coupling module for a high-speed road photovoltaic grid-connected power generation device as described in claim 1, characterized in that, The power coupling module further includes: A photovoltaic-side current detection circuit includes a first shunt resistor (R1), a photovoltaic-side high-frequency bypass capacitor (C5), and a photovoltaic-side current limiting resistor (R4). The first shunt resistor (R1) is connected in series between the photovoltaic-side power supply (VIN) and the first switching transistor (U4). The photovoltaic-side high-frequency bypass capacitor (C5) and the photovoltaic-side current limiting resistor (R4) are connected in series and in parallel with the first shunt resistor (R1). A photovoltaic-side current sampling pin (CSN2) for detecting the photovoltaic-side current is provided between the photovoltaic-side high-frequency bypass capacitor (C5) and the photovoltaic-side current limiting resistor (R4). The grid-connected current detection circuit includes a second shunt resistor (R2), a grid-connected high-frequency bypass capacitor (C6), and a grid-connected current limiting resistor (R5). The second shunt resistor (R2) is connected in series between the grid-connected power supply (VBUS) and the third switching transistor (U5). The grid-connected high-frequency bypass capacitor (C6) and the grid-connected current limiting resistor (R5) are connected in series and in parallel with the second shunt resistor (R2). A grid-connected current sampling pin (CSP1) for detecting the grid-connected current is provided between the grid-connected high-frequency bypass capacitor (C6) and the grid-connected current limiting resistor (R5).

3. The isolated power coupling module for a high-speed road photovoltaic grid-connected power generation device as described in claim 2, characterized in that, The first shunt resistor (R1) and the second shunt resistor (R2) have the same resistance value.

4. The isolated power coupling module for a high-speed road photovoltaic grid-connected power generation device as described in claim 2, characterized in that, It also includes a first bootstrap pin (BST1) and a second bootstrap pin (BST2), the second bootstrap pin (BST2) being located between the second power switch node (LX2) and the coupled inductor (L1), and the first bootstrap pin (BST1) being located between the first power switch node (LX1) and the coupled inductor (L1). It also includes a photovoltaic-side bootstrap circuit, which includes a first switching transistor (U4) as a bootstrap diode and a photovoltaic-side bootstrap capacitor (C7), which is connected across the second bootstrap pin (BST2) and the photovoltaic-side power switching node (LX2). It also includes a grid-connected bootstrap circuit, which includes the third switch (U5) as a bootstrap diode and a grid-connected bootstrap capacitor (C8), which is connected across the second bootstrap pin (BST2) and the grid-connected power switch node (LX1).

5. The isolated power coupling module for a high-speed road photovoltaic grid-connected power generation device as described in claim 1, characterized in that, Also includes: A photovoltaic-side RC absorption network is connected between the end of the coupled inductor (L1) closest to the photovoltaic-side bridge arm and ground; The grid-connected RC absorption network is connected between the end of the coupled inductor (L1) near the grid-connected bridge arm and ground.

6. The isolated power coupling module for a high-speed road photovoltaic grid-connected power generation device as described in claim 5, characterized in that, The photovoltaic-side RC absorption network and the grid-connected-side RC absorption network have the same resistance and capacitance values, forming a symmetrical structure.

Images