Inverter power module based on active voltage sag treatment device

Abstract

The utility model aims to provide the inverter power module based on the active voltage sag treatment device, which not only can meet the requirement of voltage sag compensation time, but also can cancel a laminated busbar and a thin-film capacitor on a direct current bus capacitor side, saves system cost, can plug and unplug the whole inverter power module, facilitates parallel operation of the modules, and improves the working efficiency of the inverter power module. The maintenance is convenient. The device comprises an alternating current side conductive clamp, an alternating current fuse, an IGBT module, an IGBT absorption capacitor, a bus side electrolytic capacitor, a direct current main contactor and a direct current side conductive clamp, the alternating current side conductive clamp comprises a first conductive clamp, a second conductive clamp and a third conductive clamp, and the alternating current fuse comprises a first fuse, a second fuse and a third fuse. The IGBT module comprises a first IGBT tube, a second IGBT tube and a third IGBT tube, the IGBT absorption capacitor comprises a first capacitor, a second capacitor and a third capacitor, and the direct current side conductive clamp comprises a fourth conductive clamp and a fifth conductive clamp. The device is applied to the technical field of low-voltage sag treatment.

Description

Technical Field

[0001] This utility model relates to the technical field of voltage sag, and in particular to an inverter power module based on an active voltage sag mitigation device. Background Technology

[0002] The most common power quality problems in power grids are voltage dips, voltage swells, overvoltages, undervoltages, and voltage imbalances. These power quality events can lead to load tripping and equipment failures, causing economic losses ranging from hundreds of thousands to tens of millions of dollars due to product quality incidents, to major safety accidents, resulting in huge economic losses and severe social impacts for businesses and society. Many factors can cause voltage dips, including short-circuit faults, lightning strikes, and the starting of large motors in the transmission and distribution system. Voltage dips are generally unavoidable.

[0003] Therefore, research on the propagation mechanism and key technologies for voltage sag mitigation is crucial for providing users with reliable and high-quality power. To address voltage sag issues, an active voltage sag mitigation device based on fast switching has emerged. The device operates as follows: Under normal grid conditions, the grid supplies power to sensitive loads via a fast switch, while the inverter power module and energy storage unit in the device are in grid-connected standby mode. When a voltage sag occurs, the fast switch quickly disconnects the grid, and simultaneously, the inverter power module and energy storage unit rapidly output a voltage with the same phase and amplitude as the grid to supply power to the sensitive load, ensuring uninterrupted power supply. When the grid returns to normal, the fast switch closes, and the inverter power module reconnects to the grid with a voltage of the same phase and amplitude, gradually reducing its output to avoid impacting the grid and load during the rapid disconnection process. The load is then supplied by the grid again. Therefore, the inverter power module plays a critical role in the entire active voltage sag mitigation device, and in-depth research on it has significant social and economic value.

[0004] For example, Chinese patent CN212677060U discloses a voltage sag power module. This patent provides a voltage sag power module that is small in size and easy to install and maintain through modular design of sheet metal components, copper busbar components, insulation components and functional components, which solves the problem of complex structure of existing voltage sag power modules.

[0005] For example, Chinese patent CN205092782U discloses an inverter module layout structure. By adopting a reasonable inverter module layout structure, this patent solves the system heat dissipation problem, reduces the current ripple on the thin film capacitor, improves the capacitor utilization rate, improves the working reliability of the inverter module, and reduces the overall size and system cost.

[0006] For example, Chinese patent CN211296197U discloses a power module hot-swappable connection structure, which has the following advantages: when the maintenance module is plugged in or unplugged, it will not cause communication interruption of the downstream power module. During maintenance, the redundant module can still perform grid voltage compensation in real time. It can realize the true power module hot-swappable function, which is convenient for maintenance. It does not require the use of dedicated maintenance buttons and switches. The structure is simple, the number of hot-swappable terminals is small, and the reliability is high.

[0007] In view of the current research status of the aforementioned patents, it is necessary to provide an inverter power module based on an active voltage sag mitigation device. This module can not only meet the requirements of voltage sag compensation time, but also eliminate the stacked busbar and thin film capacitor on the DC bus capacitor side, saving system costs. Furthermore, the entire inverter power module can be plugged in and out, facilitating module parallel operation and maintenance. Utility Model Content

[0008] The technical solution adopted by this utility model is as follows: This utility model includes an AC side conductive clamp, an AC fuse, an IGBT module, an IGBT absorption capacitor, a bus-side electrolytic capacitor, a DC main contactor, and a DC side conductive clamp. The AC side conductive clamp includes a first conductive clamp, a second conductive clamp, and a third conductive clamp. The AC fuse includes a first fuse, a second fuse, and a third fuse. The IGBT module includes a first IGBT tube, a second IGBT tube, and a third IGBT tube. The IGBT absorption capacitor includes a first capacitor, a second capacitor, and a third capacitor. The DC side conductive clamp includes a fourth conductive clamp and a fifth conductive clamp.

[0009] The input terminal of the AC-side conductive clamp is connected to the AC input voltage. The input terminal of the AC fuse is connected to the output terminal of the AC-side conductive clamp. The AC input terminal of the IGBT module is connected to the output terminal of the AC fuse. The DC output terminal of the IGBT module is connected in parallel with the bus-side electrolytic capacitor. The IGBT absorption capacitor is connected in parallel with the bus voltage of the IGBT module. The fourth conductive clamp is connected to the output terminal of the DC main contactor. The fifth conductive clamp is connected to the negative terminal of the DC bus voltage.

[0010] As can be seen from the above, in the active voltage sag mitigation device, considering the operating time requirements, this application welds the bus-side electrolytic capacitor onto the designed circuit board, using the bus-side electrolytic capacitor to replace the laminated busbar and film capacitor. After testing, it was verified that the circuit board can operate at full load of 500A for 1 minute, meeting the on-site power replenishment needs. This method not only reduces the size of the inverter power module and lowers the module cost, but also uses pluggable conductive clips for the AC and DC input terminals of the module, which facilitates module parallel operation and maintenance.

[0011] In a preferred embodiment, the inverter power module based on the active voltage sag mitigation device further includes a DC discharge circuit, which includes a discharge contactor and a discharge resistor. The discharge contactor is connected in series with the discharge resistor, and the DC discharge circuit is connected in parallel with the DC bus voltage.

[0012] In a preferred embodiment, the inverter power module based on the active voltage sag mitigation device further includes a DC soft start circuit. The DC soft start circuit includes a soft start contactor and a soft start resistor. The input terminal of the soft start contactor is connected to the positive terminal of the DC bus voltage, the output terminal of the soft start contactor is connected to the input terminal of the soft start resistor, the output terminal of the soft start resistor is connected to the output terminal of the DC main contactor, and the input terminal of the DC main contactor is connected to the positive terminal of the DC bus voltage and is connected in parallel with the input terminal of the soft start contactor.

[0013] In a preferred embodiment, the inverter power module based on the active voltage sag mitigation device further includes an IGBT driver board, which is connected to the IGBT module and provides an appropriate gate voltage to the IGBT module.

[0014] In a preferred embodiment, the inverter power module based on the active voltage sag mitigation device further includes a heat sink, and the IGBT module is mounted on the heat sink.

[0015] In a preferred embodiment, the inverter power module based on the active voltage sag mitigation device further includes a chassis, the chassis including a housing base, the housing base being uniformly coated with thermal grease, and the heat sink being disposed inside the chassis. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the principle of this utility model.

[0017] Figure 2 This is an internal structural diagram of the IGBT installation of this utility model.

[0018] Figure 3 This is an internal structural diagram of the electrolytic capacitor installation on the bus side.

[0019] Figure label:

[0020] 1. DC main contactor KM4; 2. Heat sink; 3. IGBT module; 4. IGBT driver board; 5. DC side conductive clamp; 6. AC side conductive clamp; 7. AC fuse; 8. IGBT absorption capacitor; 9. Busbar side electrolytic capacitor. Detailed Implementation

[0021] like Figures 1 to 3As shown, in this embodiment, the present invention includes an AC side conductive clamp, an AC fuse, an IGBT module, an IGBT absorption capacitor, a bus-side electrolytic capacitor C41, a DC main contactor KM4, and a DC side conductive clamp. The AC side conductive clamp includes a first conductive clamp T1, a second conductive clamp T2, and a third conductive clamp T3. The AC fuse includes a first fuse FU1, a second fuse FU2, and a third fuse FU3. The IGBT module includes a first IGBT tube VT1, a second IGBT tube VT2, and a third IGBT tube VT3. The IGBT absorption capacitor includes a first capacitor C51, a second capacitor C52, and a third capacitor C53. The DC side conductive clamp includes a fourth conductive clamp T4 and a fifth conductive clamp T5.

[0022] The input terminal of the AC side conductive clamp is connected to the AC input voltage. The input terminal of the AC fuse is connected to the output terminal of the AC side conductive clamp. The AC input terminal of the IGBT module is connected to the output terminal of the AC fuse. The DC output terminal of the IGBT module is connected in parallel with the bus-side electrolytic capacitor C41. The IGBT absorption capacitor is connected in parallel with the bus voltage of the IGBT module. The fourth conductive clamp T4 is connected to the output terminal of the DC main contactor KM4. The fifth conductive clamp T5 is connected to the negative terminal of the DC bus voltage UDC.

[0023] The main function of the AC fuse is to provide short-circuit protection and severe overload protection. The fuse cuts off the circuit by melting the fuse wire, preventing equipment damage or fire caused by excessive current.

[0024] The AC-side conductive clamp and the DC-side conductive clamp are of the same model, both being multi-point contact primary plugs. Developed using internationally advanced electrical contact conduction theory, these products are used for primary current transmission in the drawers of withdrawable low-voltage switchgear. They offer reliable contact, long lifespan, and low insertion / removal force. When transmitting the same current, the operating temperature of this plug is significantly lower than that of ordinary plugs. These conductive clamps are used on the AC and DC input / output terminals of inverter power modules, facilitating insertion and removal and enabling parallel operation of multiple modules.

[0025] The IGBT absorption capacitor, with its low equivalent series inductance and small equivalent series resistance (ESR), plays a role in absorbing voltage spikes and suppressing overcurrents in the circuit, protecting the IGBT module from damage caused by high pulse voltages.

[0026] The bus-side electrolytic capacitor C41 mainly plays the following roles in the system:

[0027] (1) Smoothing voltage: The electrolytic capacitor connected to the bus can smooth the voltage, reduce voltage fluctuations in the circuit, and improve system stability;

[0028] (2) Reducing electromagnetic interference: Electromagnetic interference is generated between various electronic components in a circuit, affecting the normal operation of the circuit. Electrolytic capacitors on the busbar can absorb high-frequency noise in the circuit, reduce electromagnetic interference, and improve the anti-interference capability of the system;

[0029] (3) Improve system stability: Electrolytic capacitors can reduce voltage fluctuations in the circuit, reduce system noise and jitter, thereby improving the reliability and stability of the system;

[0030] (4) Equipment protection: Electrolytic capacitors can also protect the inverter power module from instantaneous peak impacts of the power grid, ensuring the normal operation of the equipment.

[0031] The DC main contactor KM4 plays a crucial role in the inverter power module, enabling the charging and discharging control of the battery and thus achieving bidirectional energy flow. When an abnormality occurs during battery discharge, it can quickly disconnect the circuit, ensuring the safe operation of the equipment and system.

[0032] like Figure 1 As shown, in this embodiment, the inverter power module based on the active voltage sag control device further includes a DC discharge circuit. The DC discharge circuit includes a discharge contactor 1KA and a discharge resistor R5. The discharge contactor 1KA and the discharge resistor R5 are connected in series, and the DC discharge circuit is connected in parallel with the DC bus voltage UDC.

[0033] When the inverter power module is turned off, the DC discharge circuit discharges the capacitor voltage on the DC bus side to ensure that the voltage inside the inverter module drops to zero before maintenance and repair can be performed.

[0034] like Figure 1 As shown, in this embodiment, the inverter power module based on the active voltage sag control device further includes a DC soft start circuit. The DC soft start circuit includes a soft start contactor KM6 and a soft start resistor R6. The input terminal of the soft start contactor KM6 is connected to the positive terminal of the DC bus voltage UDC. The output terminal of the soft start contactor KM6 is connected to the input terminal of the soft start resistor R6. The output terminal of the soft start resistor R6 is connected to the output terminal of the DC main contactor KM4. The input terminal of the DC main contactor KM4 is connected to the positive terminal of the DC bus voltage UDC and is connected in parallel with the input terminal of the soft start contactor KM6.

[0035] The DC soft-start circuit refers to a method of gradually increasing the output voltage during startup, bringing it closer to normal operating conditions. This method helps reduce energy surges, lowers the probability of inverter power module failure, and extends the lifespan of the inverter module.

[0036] like Figures 2 to 3 As shown, in this embodiment, the inverter power module based on the active voltage sag control device further includes an IGBT driver board, which is connected to the IGBT module and provides an appropriate gate voltage to the IGBT module.

[0037] The primary purpose of the IGBT driver board is to control the switching action of the IGBTs, ensuring their normal operation. It receives commands from the control system and provides appropriate gate voltages to the IGBT module, thereby controlling the IGBT module's turn-on and turn-off. The IGBT driver board is fixedly mounted on the IGBT module with screws, and its control is crucial for ensuring the stability and reliability of the entire inverter power module.

[0038] like Figures 2 to 3 As shown, in this embodiment, the inverter power module based on the active voltage sag mitigation device further includes a heat sink, and the IGBT module is mounted on the heat sink.

[0039] like Figures 2 to 3 As shown, in this embodiment, the inverter power module based on the active voltage sag mitigation device further includes a chassis, the chassis including a housing base, the housing base being uniformly coated with thermal grease, and the heat sink being disposed inside the chassis.

[0040] The IGBT module uses a three-phase bridge inverter circuit composed of three IGBT transistors. The heat generated by the internal losses of the IGBT transistor chip is transferred to the housing base through the chip, and then a small amount of heat is directly transferred to the environment by the housing. Most of the heat is dissipated by uniformly coating the base with thermal grease to reduce surface contact thermal resistance, then mounting it on the heat sink for heat dissipation, and finally the heat sink transfers the heat to the air.

[0041] In this embodiment, this application is widely used in the fields of low-voltage power sloshing control, such as the semiconductor industry, steel industry, and petrochemical industry, to provide backup short-term energy storage solutions.

[0042] Although the embodiments of this utility model are described with reference to actual solutions, they do not constitute a limitation on the meaning of this utility model. For those skilled in the art, modifications to the implementation schemes and combinations with other schemes based on this specification are obvious.

Claims

1. An inverter power module based on an active voltage sag mitigation device, characterized in that: It includes an AC side conductive clamp, an AC fuse, an IGBT module, an IGBT absorption capacitor, a bus-side electrolytic capacitor (C41), a DC main contactor (KM4), and a DC side conductive clamp. The AC side conductive clamp includes a first conductive clamp (T1), a second conductive clamp (T2), and a third conductive clamp (T3). The AC fuse includes a first fuse (FU1), a second fuse (FU2), and a third fuse (FU3). The IGBT module includes a first IGBT tube (VT1), a second IGBT tube (VT2), and a third IGBT tube (VT3). The IGBT absorption capacitor includes a first capacitor (C51), a second capacitor (C52), and a third capacitor (C53). The DC side conductive clamp includes a fourth conductive clamp (T4) and a fifth conductive clamp (T5). The input terminal of the AC side conductive clamp is connected to the AC input voltage. The input terminal of the AC fuse is connected to the output terminal of the AC side conductive clamp. The AC input terminal of the IGBT module is connected to the output terminal of the AC fuse. The DC output terminal of the IGBT module is connected in parallel with the bus-side electrolytic capacitor (C41). The IGBT absorption capacitor is connected in parallel with the bus voltage of the IGBT module. The fourth conductive clamp (T4) is connected to the output terminal of the DC main contactor (KM4). The fifth conductive clamp (T5) is connected to the negative terminal of the DC bus voltage (UDC).

2. The inverter power module based on an active voltage sag control device according to claim 1, characterized in that: The inverter power module based on the active voltage sag control device also includes a DC discharge circuit, which includes a discharge contactor (1KA) and a discharge resistor (R5). The discharge contactor (1KA) and the discharge resistor (R5) are connected in series, and the DC discharge circuit is connected in parallel with the DC bus voltage (UDC).

3. The inverter power module based on an active voltage sag mitigation device according to claim 1, characterized in that: The inverter power module based on the active voltage sag control device also includes a DC soft start circuit, which includes a soft start contactor (KM6) and a soft start resistor (R6). The input terminal of the soft start contactor (KM6) is connected to the positive terminal of the DC bus voltage (UDC), the output terminal of the soft start contactor (KM6) is connected to the input terminal of the soft start resistor (R6), the output terminal of the soft start resistor (R6) is connected to the output terminal of the DC main contactor (KM4), and the input terminal of the DC main contactor (KM4) is connected to the positive terminal of the DC bus voltage (UDC) and is connected in parallel with the input terminal of the soft start contactor (KM6).

4. An inverter power module based on an active voltage sag mitigation device according to claim 1, characterized in that: The inverter power module based on the active voltage sag control device also includes an IGBT driver board, which is connected to the IGBT module and provides an appropriate gate voltage to the IGBT module.

5. An inverter power module based on an active voltage sag mitigation device according to claim 1, characterized in that: The inverter power module based on the active voltage sag mitigation device also includes a heat sink, and the IGBT module is mounted on the heat sink.

6. An inverter power module based on an active voltage sag mitigation device according to claim 5, characterized in that: The inverter power module based on the active voltage sag mitigation device also includes a chassis, which includes a base shell uniformly coated with thermal grease, and a heat sink disposed inside the chassis.

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