A power unit for a large-capacity asvg of a 600v voltage class

Abstract

The utility model discloses a kind of power units for 600V voltage grade large capacity ASVG, belong to grid reactive power compensation field, including the cabinet formed by power unit bottom plate, top cover plate, front panel and rear panel, radiator, IGBT module, RC absorption plate, capacitor plate, laminated busbar, main control board, sampling protection plate, power board and output current hall mutual inductor are equipped in cabinet.IGBT module's upper half bridge and lower half bridge closely adhere to constitute complete bridge arm, bridge arm is fixed to radiator and parallel RC absorption plate;Multiple capacitor plates are connected by laminated busbar in parallel, simultaneously connect IGBT module direct current input end;Main control board combines sampling protection plate and output current hall mutual inductor acquisition signal, control IGBT module output.This unit adapts 600V grid, can reduce stray inductance and capacitor heat, realize reactive accurate compensation, improve ASVG operating stability and efficiency.

Description

Technical Field

[0001] This utility model relates to the field of reactive power compensation technology for power grids, and in particular to a power unit for a large-capacity ASVG with a voltage level of 600V. Background Technology

[0002] In the field of reactive power compensation for 600V power grids, traditional reactive power compensation equipment mainly consists of thyristor switched filters (TFC). TFC is composed of thyristors and filter branches. It forms a low-impedance path at specific harmonic frequencies (such as the 5th and 7th harmonics) through LC series resonance, thereby achieving fixed-order harmonic filtering. It has the advantages of low cost and low heat generation, but it has significant drawbacks: it can only compensate capacitive reactive power, has a slow response speed (20-40ms), and the compensation method is stepped, which cannot achieve continuous and smooth compensation.

[0003] Static var generators (ASVG, also known as enhanced static var generators) are a new generation of reactive power compensation devices characterized by high real-time performance and low harmonic content. By adjusting the amplitude and phase of the inverter output voltage, they can quickly compensate for both capacitive and inductive reactive power in the power grid bidirectionally, while effectively suppressing low-order harmonic currents. Compared to two-level ASVGs, three-level ASVGs have smaller output voltage fluctuations and lower harmonic content, allowing for smaller filter sizes; furthermore, their switching devices have lower withstand voltages and lower switching losses, making them more suitable for high-voltage, high-power applications, leading to their increasingly widespread use.

[0004] However, existing high-capacity ASVG still has the following problems in power unit design and application: 1. The challenge of balancing the number of modules and capacity: Large-capacity ASVG needs to be achieved through parallel connection of power units, but too many modules will increase control complexity and easily cause oscillations between modules; if the capacity of a single module is too large, it will lead to increased weight and difficulty in heat dissipation, which is not conducive to installation and maintenance, making it difficult to achieve a balance between the two.

[0005] 2. Stray Inductance and Heat Dissipation Issues in Three-Level Bridge Arms: In three-level I-type topology IGBT modules, the upper and lower half-bridges are usually packaged separately and need to be connected in series to form a complete bridge arm. Each phase contains four IGBT modules (two upper half-bridges and two lower half-bridges). Their arrangement directly affects stray inductance and heat dissipation: If the modules are arranged dispersed to achieve uniform heat dissipation, the connection distance between modules will increase, leading to higher stray inductance. This can cause excessively high voltage when the IGBT is turned off, making it prone to breakdown under high current conditions, resulting in bridge arm damage. Conversely, simply shortening the module spacing may lead to poor local heat dissipation, causing thermal runaway.

[0006] 3. IGBT internal transistor turn-off voltage spike problem: Even with optimized module arrangement, stray inductance cannot be completely eliminated. The stray inductance will generate voltage spikes when the IGBT internal transistor is turned off. If the voltage spike exceeds the device's withstand voltage, it will cause damage to the internal transistor.

[0007] 4. DC side capacitor heating problem: Traditional large-capacity ASVG uses single large-capacity electrolytic capacitors (27) connected in parallel. These capacitors have a large parasitic resistance (ESR), which causes serious heat generation during operation, affecting capacitor life and system stability. Utility Model Content

[0008] The purpose of this invention is to provide a high-capacity ASVG power unit with a voltage level of 600V, which has low output harmonic content, low switching loss, and uniform heat dissipation, and is suitable for efficient reactive power compensation in 600V voltage level power grids.

[0009] To achieve the above objectives, this utility model provides a high-capacity ASVG power unit with a voltage level of 600V, including a chassis, a main control board (001), a sampling protection board (030), a power supply board (017), a heat sink (014), a capacitor board (020), an IGBT module (012), an RC absorption board (011), a laminated busbar (015), and an output current Hall transformer (004). The chassis is made of aluminum-zinc coated material and is enclosed by a power unit base plate (023), a top cover plate (002), a front panel (024) and a rear panel (009) to form a closed installation space; The heat sink (014) is fixed on the power unit base plate (023) inside the chassis; the IGBT module (012) includes an upper half-bridge module and a lower half-bridge module, which are closely fitted together to form a complete bridge arm. Each complete bridge arm is fixed above the heat sink (014), and each phase includes two complete bridge arms. The RC absorption plate (011) is connected in parallel to both ends of the inner tube of each IGBT module (012) and is fixed to the IGBT module (012) by fasteners; The capacitor board (020) consists of 6 discrete plates. Each capacitor board (020) is connected in parallel through the stacked busbar (015). The stacked busbar (015) is also fixed to the DC input terminal of the IGBT module (012). The main control board (001), sampling protection board (030), and power supply board (017) are all fixed inside the chassis; the main control board (001) is connected to the IGBT module (012) via a ribbon cable through the drive distribution board (016); the sampling protection board (030) is connected to the temperature detection component and the output current Hall transformer (004) of the IGBT module (012); the power supply board (017) is connected to the main control board (001) and the sampling protection board (030). The output current Hall transformer (4) is fixed on the output current Hall transformer fixing bracket (008).

[0010] Preferably, the mating surfaces of the upper half-bridge module and the lower half-bridge module of the IGBT module (012) are fastened with screws, and the length of the connecting copper busbar between the upper half-bridge module and the lower half-bridge module does not exceed 5cm.

[0011] Preferably, the stacked busbar (015) has three conductive layers, namely BUS+ layer, BUS- layer and N layer, and an insulating layer is provided between adjacent conductive layers and they are tightly stacked; the connection end of the stacked busbar (015) to the capacitor board (020) is fixed by screws, and the connection end to the DC input end of the IGBT module (012) is superimposed with an absorption capacitor (013) and then fixed by screws.

[0012] Preferably, the capacitor board (020) is a PCB board, and an electrolytic capacitor (027) is soldered on the PCB board. The chassis is also provided with a capacitor module support frame (022) and a capacitor module tray (021). The capacitor module support frame (022) is vertically fixed on the power unit base plate (023), and the capacitor module tray (021) is fixed above the capacitor module support frame (022) and parallel to the power unit base plate (023). The capacitor board (020) is fixed on the capacitor module tray (021) by capacitor board fixing support studs (026), and an insulating plate (025) is provided between the capacitor board (020) and the capacitor module tray (021).

[0013] Preferably, there are 3 heat sinks (014), and the complete bridge arms of the 3 heat sinks (014) are evenly distributed along the length of the heat sink (014); thermally conductive silicone grease is applied between the bottom metal heat dissipation surface of the IGBT module (012) and the contact surface of the heat sink (014).

[0014] Preferably, the main control board (001) integrates a DSP chip and an FPGA. The FPGA is also connected to an AD sampling chip. The sampling terminals of the AD sampling chip are respectively connected to the three-phase system voltage sampling terminal, the DC side voltage sampling terminal, and the three-phase Hall output current sampling terminal. The main control board (001) is connected to the drive distribution board (016) through a 2×10 ribbon cable. The drive distribution board (016) is connected to the IGBT module (012) through a 2×10 ribbon cable.

[0015] Preferably, the chassis is also provided with an output current Hall transformer fixing bracket (008), the output current Hall transformer fixing bracket (008) is fixed to the fixing bracket (031) by screws, the fixing bracket (031) is fixed to the inside of the rear panel (009) by screws, the output current Hall transformer (004) is fixed to the output current Hall transformer fixing bracket (008) by screws; the output wire of the output current Hall transformer (004) is laid along the output current Hall transformer fixing bracket (008) and fixed by cable ties.

[0016] Preferably, a heat dissipation gap is reserved between the capacitor module support frame (0022) and the power unit base plate (023), and the chassis forms a heat dissipation channel with front air and rear air. Cold air enters from the gap in the front panel (024), flows through the heat dissipation gap through the heat sink (014), and is discharged from the gap in the rear panel (009).

[0017] Preferably, a first navigation plug (028) and a second navigation plug (018) are also fixed on the front panel (024); one end of the first navigation plug (028) is connected to the voltage input terminal of the sampling protection board (030) via a cable, and the other end is used to connect to the three-phase system voltage; one end of the second navigation plug (018) is connected to the communication interface of the main control board (001) via a cable, and the other end is used to connect to the external communication line.

[0018] Preferably, a light board (029) is also fixed on the front panel (024). The light board (029) is equipped with a five-position 8421 code DIP switch and two red LED indicator lights. The light board (029) is connected to the main control board (001) through a 2×5 ribbon cable.

[0019] Therefore, the high-capacity ASVG power unit with a voltage level of 600V that adopts the above structure has the following technical effects: 1. By closely fitting the upper and lower half-bridges of the IGBT to shorten the connection distance and using a three-layer stacked busbar, the stray inductance of the three-level bridge arm is significantly reduced. Furthermore, the RC snubber plate connected in parallel with the IGBT inner tube can effectively absorb the voltage spikes when the inner tube is turned off, preventing the IGBT from breaking down due to excessive voltage and improving the reliability of the device.

[0020] 2. The design of multiple discrete PCB capacitor boards connected in parallel through stacked busbars significantly reduces the equivalent parasitic resistance on the DC side, thereby reducing the heat generated during capacitor operation, preventing capacitor degradation due to overheating, extending capacitor life, and improving DC side voltage stability.

[0021] 3. By using independent heat sinks that are evenly distributed, with reserved heat dissipation gaps and a heat dissipation channel designed for front and rear airflow, combined with the thermal conductivity treatment between the IGBT and the heat sink, the heat generated during device operation can be efficiently dissipated, preventing thermal runaway caused by local overheating of core components such as the IGBT, and ensuring long-term stable operation of the unit.

[0022] 4. Based on the control architecture of DSP and FPGA working together, combined with three-level topology and SPWM modulation, it can not only quickly respond to the reactive power demand of the power grid and realize continuous adjustment of capacitive and inductive reactive power, but also reduce the harmonic content of output current, reduce harmonic pollution to the power grid, and adapt to the dynamic reactive power compensation needs of the power grid.

[0023] 5. The design of status indicators and address identification on the lamp board, along with the modular assembly of discrete components, facilitates troubleshooting and component replacement. At the same time, the core component parameters are optimized for the 600V voltage level, which can be directly applied to industrial power grids of this voltage level, effectively improving the power factor of the grid and meeting the requirements for grid stability and energy saving.

[0024] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the internal structure of a power unit for a large-capacity ASVG with a voltage level of 600V according to this utility model. Figure 2 This is a front view of the power unit structure according to an embodiment of the present invention; Figure 3 This is a top view of the power unit structure of this utility model; Figure 4 This is a side view of the power unit structure of this utility model; Figure 5 This is a longitudinal cross-sectional view of the power unit structure of this utility model; Figure 6 This is a schematic diagram of the output current Hall transformer and its connection structure of the present invention; Figure 7 This is a schematic diagram of the connection structure between the IGBT module and the heat sink of this utility model.

[0026] Figure Labels 001. Main control board; 002. Top cover plate; 003. Output busbar; 004. Output current Hall transformer; 005. Output connection bar; 006. Output connector; 007. Bridge arm output bar; 008. Output current Hall transformer mounting bracket; 009. Rear panel; 010. Rear panel mounting plate; 011. RC absorption plate; 012. IGBT module; 013. Absorption capacitor; 014. Heat sink; 015. Laminated busbar; 016. Drive sub-module Components: 017, Power board; 018, Second-line connector; 019, Circuit board tray; 020, Capacitor board; 021, Capacitor module tray; 022, Capacitor module support frame; 023, Power unit base plate; 024, Front panel; 025, Insulating board; 026, Capacitor board fixing support studs; 027, Electrolytic capacitor; 028, First-line connector; 029, Lamp board; 030, Sampling protection board; 031, Fixing bracket; 032, Output connector fixing piece. Detailed Implementation

[0027] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.

[0028] Example like Figure 1 As shown, a high-capacity ASVG power unit with a voltage level of 600V includes a chassis, a main control board (001), a sampling protection board (030), a power supply board (017), a heat sink (014), a capacitor board (020), an IGBT module (012), an RC absorption board (011), a laminated busbar (015), and an output current Hall transformer (004).

[0029] The chassis is made of aluminum-zinc coated material and consists of a power unit base plate (023), a top cover plate (002), a front panel (024), and a rear panel (009) forming a closed installation space. The aluminum-zinc coated material ensures the overall structural strength to stably support the components and also provides some rust resistance, extending the unit's service life. The top cover plate (002) uses a snap-on design for quick disassembly and assembly for subsequent maintenance. Figure 2 , Figure 3 , Figure 4 The front view, top view, and side view of the power unit are shown respectively.

[0030] Figure 5 The longitudinal cross-sectional structure of the power module is shown. The IGBT module (012) comprises six Infineon three-level upper half-bridge modules (model F3L300R12ME4_B22) and six Infineon three-level lower half-bridge modules (model F3L300R12ME4_B23). The upper and lower half-bridge modules are tightly fitted together and connected via bridge arm output bars (007) to form a complete bridge arm. The length of the bridge arm output bars (007) between the upper and lower half-bridge modules does not exceed 5cm, which significantly reduces stray inductance and minimizes the risk of voltage spikes when the IGBT module (012) is turned off.

[0031] Each heat sink (014) has a complete bridge arm evenly distributed along its length. Thermal grease is applied between the bottom metal heat dissipation surface and the contact surface of the heat sink (014) to enhance heat conduction efficiency. Each phase consists of two complete bridge arms connected in parallel and fixed above the heat sink (014). The three heat sinks (014) are fixed on the power unit base plate (023) inside the chassis and are evenly arranged along the length of the power unit base plate (023). The spacing between adjacent heat sinks (014) is adapted to the heat dissipation requirements of the IGBT module (012) to avoid heat concentration.

[0032] like Figure 7 As shown, an RC absorption plate (011) is connected in parallel to both ends of the inner tube of each IGBT module (012). The RC absorption plate (011) is fixed to the IGBT module (012) by screws, which can directly and quickly absorb the voltage spike generated when the inner tube of the IGBT module (012) is turned off, and further protect the IGBT module (012) from overvoltage damage.

[0033] The stacked busbar (015) has three conductive layers: BUS+, BUS-, and N. An insulating layer is provided between adjacent conductive layers, and they are tightly stacked. The connection between the stacked busbar (015) and the capacitor board (020) is fixed with screws. The connection between the stacked busbar (015) and the DC input terminal of the IGBT module (012) is secured with screws after being superimposed with a 10μF / 1600V absorption capacitor (013).

[0034] The chassis also includes a capacitor module support frame (022) and a capacitor module tray (021). The capacitor module support frame (022) is vertically fixed on the power unit base plate (023), and the capacitor module tray (021) is fixed above the capacitor module support frame (022) and parallel to the power unit base plate (023). Six separate PCB capacitor boards (020) are mounted on the capacitor module tray (021) via capacitor board fixing support studs (026). An insulating plate (025) is placed between the capacitor board (020) and the capacitor module tray (021) to achieve electrical isolation and avoid the risk of leakage.

[0035] The capacitor board (020) is a PCB board, and electrolytic capacitors (027) are soldered onto the PCB board. The capacitor boards (020) are connected in parallel via a stacked busbar (015). This design of multiple capacitor boards (020) connected in parallel with the stacked busbar (015) significantly reduces the equivalent parasitic resistance on the DC side, reduces the heat generated during capacitor operation, and extends the service life of the capacitors. At the same time, the structure of the stacked busbar (015) can further reduce the stray inductance of the circuit and improve the uniformity of current distribution.

[0036] The chassis also houses a circuit board tray (019), on which the main control board (001), sampling protection board (030), drive distribution board (016), and power supply board (017) are all fixed. The main control board (001) is connected to the drive distribution board (016) via a 2×10 ribbon cable, and the drive distribution board (016) is connected to the IGBT module (012) via a 2×10 ribbon cable. This hierarchical connection method ensures stable transmission of the PWM control signal and reduces signal interference.

[0037] The main control board (001) integrates a DSP chip (model TMS320F28335) and an FPGA (model XC3S400). The FPGA is also connected to an AD sampling chip. The DSP chip is responsible for logic control, digital input / output, and instruction calculation, while the FPGA is responsible for PWM wave generation, NTC protection, DC voltage hardware protection, Hall current overcurrent protection, and AD sampling control.

[0038] The sampling terminals of the AD sampling chip (model AD7606) are connected to the three-phase system voltage sampling terminals (Usa, Usb, Usc), the three-phase Hall output current sampling terminals (Ioa, Iob, Ioc), and the DC voltage sampling terminals (Udc_Up, Udc_Down), respectively. It can simultaneously acquire multiple analog signals, quickly obtain power grid and unit operating status data, and improve control response speed.

[0039] The sampling protection board (030) is equipped with voltage input terminal P11, current input terminals (P2, P4, P6) and NTC input terminals (P1, P3, P5). Voltage input terminal P11 is connected to the 100V three-phase system voltage through the first connector (028), and a series voltage transformer (model TV1013) steps down the 100V line voltage to a low voltage signal, which is then input to the sampling chip AD7606 after passing through the operational amplifier conditioning circuit. The current input terminals (P2, P4, P6) are connected to three output current Hall transformers (004) through cables.

[0040] The output connector (006) is inserted from the outside of the rear panel (009), locked in place by the output connector retaining piece (032), and secured to the rear panel (009) with screws. One end of the bridge arm output bus (007) is connected to the AC output terminal of the IGBT module (012), and the other end is connected to the output bus (003). Figure 6 As shown, one end of the output connector (005) is fixed to the output connector (006) with screws, passes through the output current Hall transformer (004), and the other end is connected to the output busbar (003). The output current Hall transformer (004) is fixed on the output current Hall transformer bracket (008).

[0041] The rear panel mounting plate (010) is fixed to the rear panel (009) with screws on one side and to the radiator (014) with screws on the other side. The rear panel mounting plate (010) serves to stabilize the rear panel and the radiator.

[0042] The fixed bracket (031) is fixed on the rear panel (009), and the output current Hall transformer fixed bracket (008) is fixed on the fixed bracket (031).

[0043] The output current Hall transformer (004), model SCK3-400A, has a transformation ratio of ±400A / ±4V. It is fixed to the output current Hall transformer mounting bracket (008) on the inside of the rear panel (009) with screws. Its output wire is laid along the bracket and fixed with cable ties. The output current Hall transformer (004) converts the 300A high current into a low voltage signal, which is then conditioned by an operational amplifier and input to the sampling chip AD7606. The NTC input terminals (P1, P3, P5) are connected to the NTC resistor (10kΩ at 25℃) of the IGBT module (012) through cables. Together with the fixed resistor on the board, they form a voltage divider circuit. The voltage divider signal is input to a comparator and compared with the temperature protection threshold (3.3V at 85℃) to generate an NTC protection signal.

[0044] By connecting the temperature detection component (NTC resistor) and the output current Hall transformer (004) of the IGBT module (012) respectively with cables, the temperature and output current of the IGBT module (012) can be monitored in real time. Once over-temperature or over-current occurs, it can be promptly fed back to the main control board (001) to trigger the protection action and avoid damage to the components.

[0045] The power board (017) uses a switching power supply module (model URA2412LD, VRB2415LD, VRB2405YMD). The input terminals are connected to an external 24V switching power supply via cables, and the output terminals provide +5V and +15V voltages to the main control board (001) and ±12V voltages to the sampling protection board (030) via wires, ensuring stable power supply for the control and sampling links.

[0046] The front panel (024) is also equipped with a first connector (028) and a second connector (018). One end of the first connector (028) is connected to the voltage input terminal of the sampling protection board (030) via a cable, and the other end is used to connect to the three-phase system voltage. One end of the second connector (018) is connected to the communication interface of the main control board (001) via a cable, and the other end is used to connect to the external communication line. The two connectors realize the grid voltage access and external communication respectively, ensuring stable signal transmission.

[0047] The current control process is as follows: First, the 100V three-phase system voltage is stepped down by the TV1013 transformer of the first connector (028) and sampling protection board (030), and then sampled by the sampling chip AD7606. The DSP chip reads the sampled data and calculates the grid synchronization phase θ through the phase-locked loop (PLL). The output current is sampled by the Hall transformer (004) and conditioned by the sampling protection board (030), and then sampled by the AD7606. The DSP chip reads the current data and performs dq transformation in combination with the phase θ to obtain the actual reactive current value. The DSP chip receives the reactive current command iq_ref from the external ASVG master control system every 20ms through the CAN bus of the second connector (018), performs PI adjustment on iq_ref and the actual reactive current value, and generates the base voltage reference command Uref_. At the same time, the AD7606 samples the DC side voltage Udc, and the DSP chip performs PI regulation on Udc and the DC voltage reference value to generate an active power compensation voltage ΔU, which is superimposed on Uref_base to obtain the final voltage reference command Uref; the DSP chip transmits Uref to the FPGA, the FPGA generates a 6.4kHz triangular carrier and performs SPWM modulation with Uref to generate 6 PWM drive signals; the main control board (001) transmits the PWM signal to 3 drive distribution boards (016) through 02×10 ribbon cables, one for each corresponding to one. After the drive distribution board (016) isolates and amplifies the signal, it transmits it to the terminal of the IGBT module (012) through 2×10 ribbon cables to control the IGBT to turn on and off, adjust the amplitude and phase of the unit output current, and realize precise control of reactive current. If the sampling protection board (030) detects faults such as over-temperature or over-current (corresponding to the 3.3V threshold of 600A), it will transmit the fault signal to the FPGA, and the FPGA will immediately block the PWM pulse to protect the device.

[0048] A light board (029) is also fixed on the front panel (024). The light board (029) is connected to the main control board (001) via a 2×5 ribbon cable. The light board (029) is equipped with a five-position 8421 code DIP switch and two red LED indicator lights. The five-position 8421 code DIP switch can set the unit address. The two red LED indicator lights indicate the running and fault status respectively. The running light is off when the unit is stopped and flashes at a frequency of 1Hz when the unit is running. The fault light is always off when there is no fault and always on when there is a fault, which makes it convenient for staff to quickly identify the unit status and troubleshoot problems.

[0049] In addition, a heat dissipation gap is reserved between the capacitor module support frame (022) and the power unit base plate (023), a ventilation gap is provided on the front panel (024), and a ventilation hole is opened on the rear panel (009). Cool air enters from the gap in the front panel (024), flows through the heat dissipation gap and through the heat sink (014), and is discharged from the gap in the rear panel (009), effectively removing the heat generated by the IGBT module (012) and the capacitor, and preventing the components from being affected by overheating or damaged.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solution of this utility model, and these modifications or equivalent substitutions cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of this utility model.

Claims

1. A high-capacity ASVG power unit with a voltage rating of 600V, characterized in that: It includes a chassis, main control board (001), sampling protection board (030), power supply board (017), heat sink (014), capacitor board (020), IGBT module (012), RC absorption board (011), laminated busbar (015) and output current Hall transformer (004). The chassis is made of aluminum-zinc coated material and is enclosed by a power unit base plate (023), a top cover plate (002), a front panel (024) and a rear panel (009) to form a closed installation space; The heat sink (014) is fixed on the power unit base plate (023) inside the chassis; the IGBT module (012) includes an upper half-bridge module and a lower half-bridge module, which are closely fitted together to form a complete bridge arm. Each complete bridge arm is fixed above the heat sink (014), and each phase includes two complete bridge arms. The RC absorption plate (011) is connected in parallel to both ends of the inner tube of each IGBT module (012) and is fixed to the IGBT module (012) by fasteners; The capacitor board (020) consists of 6 discrete plates. Each capacitor board (020) is connected in parallel through the stacked busbar (015). The stacked busbar (015) is also fixed to the DC input terminal of the IGBT module (012). The main control board (001), sampling protection board (030), and power supply board (017) are all fixed inside the chassis; the main control board (001) is connected to the IGBT module (012) via a ribbon cable through the drive distribution board (016); the sampling protection board (030) is connected to the temperature detection component and the output current Hall transformer (004) of the IGBT module (012); the power supply board (017) is connected to the main control board (001) and the sampling protection board (030). The output current Hall transformer (004) is fixed on the output current Hall transformer mounting bracket (008).

2. The power unit for a high-capacity ASVG with a voltage rating of 600V according to claim 1, characterized in that: The mating surfaces of the upper and lower half-bridge modules of the IGBT module (012) are fastened with screws, and the length of the connecting copper busbar between the upper and lower half-bridge modules does not exceed 5cm.

3. The power unit for a high-capacity ASVG with a voltage rating of 600V according to claim 2, characterized in that: The stacked busbar (015) has three conductive layers, namely BUS+ layer, BUS- layer and N layer. An insulating layer is provided between adjacent conductive layers and they are tightly stacked. The connection end of the stacked busbar (015) to the capacitor board (020) is fixed by screws. The connection end of the stacked busbar (015) to the DC input end of the IGBT module (012) is superimposed with an absorption capacitor (013) and then fixed by screws.

4. The power unit for a high-capacity ASVG with a voltage rating of 600V according to claim 3, characterized in that: The capacitor board (020) is a PCB board, and electrolytic capacitors (027) are soldered on the PCB board. The chassis is also equipped with a capacitor module support frame (022) and a capacitor module tray (021). The capacitor module support frame (022) is vertically fixed on the power unit base plate (023), and the capacitor module tray (021) is fixed above the capacitor module support frame (022) and parallel to the power unit base plate (023). The capacitor board (020) is fixed on the capacitor module tray (021) by capacitor board fixing support studs (026), and an insulating plate (025) is provided between the capacitor board (020) and the capacitor module tray (021).

5. A high-capacity ASVG power unit with a voltage rating of 600V according to claim 4, characterized in that: There are 3 heat sinks (014), and the complete bridge arms of the 3 heat sinks (014) are evenly distributed along the length of the heat sink (014); thermal grease is applied between the bottom metal heat dissipation surface of the IGBT module (012) and the contact surface of the heat sink (014).

6. The power unit for a high-capacity ASVG with a voltage rating of 600V according to claim 5, characterized in that: The main control board (001) integrates a DSP chip and an FPGA. The FPGA is also connected to an AD sampling chip. The sampling terminals of the AD sampling chip are respectively connected to the three-phase system voltage sampling terminal, the DC side voltage sampling terminal, and the three-phase Hall output current sampling terminal. The main control board (001) is connected to the drive distribution board (016) through a 2×10 ribbon cable. The drive distribution board (016) is connected to the IGBT module (012) through a 2×10 ribbon cable.

7. A high-capacity ASVG power unit with a voltage rating of 600V according to claim 6, characterized in that: The chassis is also equipped with an output current Hall transformer mounting bracket (008). The output current Hall transformer mounting bracket (008) is fixed to the mounting bracket (031) by screws. The mounting bracket (031) is fixed to the inside of the rear panel (009) by screws. The output current Hall transformer (004) is fixed to the output current Hall transformer mounting bracket (008) by screws. The output wire of the output current Hall transformer (004) is laid along the output current Hall transformer mounting bracket (008) and fixed by cable ties.

8. A high-capacity ASVG power unit with a voltage rating of 600V according to claim 7, characterized in that: A heat dissipation gap is reserved between the capacitor module support frame (022) and the power unit base plate (023). The chassis forms a heat dissipation channel with front air and rear air. Cold air enters from the gap in the front panel (024), flows through the heat dissipation gap and through the heat sink (014), and is discharged from the gap in the rear panel (009).

9. A high-capacity ASVG power unit with a voltage rating of 600V according to claim 8, characterized in that: The front panel (024) is also fixed with a first navigation plug (028) and a second navigation plug (018); one end of the first navigation plug (028) is connected to the voltage input terminal of the sampling protection board (030) via a cable, and the other end is used to connect to the three-phase system voltage; one end of the second navigation plug (018) is connected to the communication interface of the main control board (001) via a cable, and the other end is used to connect to the external communication line.

10. A high-capacity ASVG power unit with a voltage rating of 600V according to claim 9, characterized in that: The front panel (024) is also fixed with a light board (029), which has a five-position 8421 code DIP switch and two red LED indicator lights. The light board (029) is connected to the main control board (001) via a 2×5 ribbon cable.

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