Chain type power unit auxiliary power circuit and power device
By using a chain-type auxiliary power circuit for power units, each pair of power units can share a single auxiliary power supply circuit, thus solving the need for isolation transformers when integrating multi-level power units and achieving a high-density and low-cost power module design.
Patent Information
- Application Number
- CN202520147339.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-22
- Publication Date
- 2026-02-03
- Estimated Expiration
- 2035-01-22
AI Technical Summary
In existing technologies, when integrating multi-level power units into a single package, an isolation transformer of the same number must be integrated, which affects the power density and cost of the power module.
A chain-type auxiliary power circuit is adopted, so that every two groups of power units share one auxiliary power supply circuit. Power is drawn from the AC side and converted before being supplied to the corresponding power units in the same group, reducing the need for isolation transformers.
This increases the power density of the power module, reduces costs and space requirements, and decreases the need for maintenance in case of isolation transformer failure.
Smart Images
Figure CN223872215U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of power electronics technology, and in particular to an auxiliary power circuit and power device for a chain-type power unit. Background Technology
[0002] Chain topology, especially cascaded topology, is widely used in high-voltage, high-capacity power electronic equipment, such as high-voltage direct-connected SVG (Static Var Generator). It also has broad application prospects in high-voltage cascaded energy storage, high-voltage frequency converters, wind power converters, and other high-voltage, high-power applications.
[0003] Under cost pressure, products are trending towards miniaturization and high integration density. As the main component of the chain structure, the cascade unit allows two or more cascade units to be integrated into a power module, thereby saving space and improving the power density of the product.
[0004] For the power supply of the control board of the power unit, since the control boards of each power unit are independent of each other, if multiple power units are integrated and packaged into a power module, the power module needs to integrate the same number of isolation transformers as the power units, which affects the power density and cost of the power module. Utility Model Content
[0005] The technical problem to be solved by this utility model is to provide a chain-type power unit auxiliary power circuit and power device to reduce the power module's need for isolation transformers, increase the power density of the power module, and reduce costs.
[0006] In a first aspect, this utility model provides a chain-type auxiliary power circuit for power units, which is applied to a power module. The power module includes several chain-connected power units, and the chain-type auxiliary power circuit includes multiple auxiliary power supply circuits. The power units are grouped in pairs, and each auxiliary power supply circuit corresponds to and is connected to each group of power units so as to draw power from the AC side of the two power units in the corresponding group, and after conversion and processing, supply auxiliary power to the two power units in the corresponding group.
[0007] Secondly, this utility model provides a power device, including a three-phase cascaded power module. Each phase cascaded power module includes several chain-connected power units and multiple chain-connected auxiliary power circuits. The AC sides of adjacent power units in each phase cascaded power module are connected in series, and the chain-connected auxiliary power circuits are connected to the corresponding power units.
[0008] The beneficial technical effects of this utility model are as follows: The auxiliary power circuit of the chain-type power unit of this utility model sets up an auxiliary power supply circuit corresponding to and connected to the power units in a chain connection between two groups of power modules. It draws power from the AC side of the two corresponding power units in the same group, and after conversion and processing, outputs two power supplies to provide auxiliary power to the two corresponding power units in the same group. This allows two cascaded power units to share a single auxiliary power supply circuit, eliminating the need for isolation transformers in each power unit, reducing the demand for isolation transformers, lowering costs and space requirements, increasing the power density of the power modules, and reducing the need for maintenance in case of isolation transformer failure, thus lowering the failure rate. The power device of this utility model also has the above-mentioned functions. Attached Figure Description
[0009] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0010] Figure 1 A schematic diagram of the auxiliary power circuit of the chain power unit provided by this utility model applied to a power module;
[0011] Figure 2 A schematic diagram showing the connection between the auxiliary power supply circuit and the power unit of the chain-type power unit auxiliary power circuit provided by this utility model.
[0012] Figure 3 A schematic diagram showing the specific connection between the auxiliary power supply circuit and the power unit in the chain-type power unit auxiliary power circuit provided by this utility model. Detailed Implementation
[0013] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.
[0014] Please see Figure 1 , Figure 1This is a schematic diagram of the chain-type power unit auxiliary power circuit 10 applied to a power module according to an embodiment of the present invention. The chain-type power unit auxiliary power circuit 10 is applied to the power module, which includes a plurality of chain-connected power units 21. The chain-type power unit auxiliary power circuit 10 includes a plurality of auxiliary power supply circuits 11. The power units 21 are grouped in pairs. Each auxiliary power supply circuit 11 corresponds to and is connected to each group of power units 21, so as to draw power from the AC side of the two power units 21 in the corresponding group, and after conversion processing, supply auxiliary power to the two power units 21 in the corresponding group.
[0015] The chain-type power unit auxiliary power circuit 10 is configured with an auxiliary power supply circuit 11 corresponding to and connected to the power units 21 of the two power modules in a chain connection. It draws power from the AC side of the two power units 21 in the same group, and then outputs two power supplies after conversion to provide auxiliary power to the two power units 21 in the same group. This allows the two cascaded power units 21 to share a single auxiliary power supply circuit 11, eliminating the need for isolation transformers for each power unit 21. This reduces the demand for isolation transformers, lowers costs and space requirements, increases the power density of the power modules, and reduces the need for maintenance in case of isolation transformer failure, thus reducing the failure rate.
[0016] Combination Figure 2 Specifically, the power unit 21 includes a control board, and the two power units 21 in the same group are a first power unit 21a and a second power unit 21b. The AC output terminal of the first power unit 21a is connected to the AC input terminal of the second power unit 21b. The AC input terminal of the first power unit 21a and the AC output terminal of the second power unit 21b are connected to the input terminal of the auxiliary power supply circuit 11, so that the auxiliary power supply circuit 11 draws power from the AC side of the corresponding chain-connected first power unit 21a and second power unit 21b. The output terminal of the auxiliary power supply circuit 11 is connected to the control board of the first power unit 21a and the control board of the second power unit 21b, respectively, to provide auxiliary power to the control boards of the first power unit 21a and the second power unit 21b, thereby realizing the auxiliary power supply to the control boards of the corresponding chain-connected first power unit 21a and second power unit 21b.
[0017] Specifically, the auxiliary power supply circuit 11 includes a rectifier unit, a capacitor bank, and an auxiliary power supply transformer T1. The input terminal of the rectifier unit serves as the input terminal of the auxiliary power supply circuit 11. The AC input terminal of the first power unit 21a and the AC output terminal of the second power unit 21b are connected to the input terminal of the rectifier unit. The output terminal of the rectifier unit is connected to the capacitor bank, which includes a first capacitor C1, a second capacitor C2, and a third capacitor C3 connected in series. The two ends of the primary winding of the auxiliary power supply transformer T1 are connected to the two ends of the second capacitor C2. Therefore, the voltage across the second capacitor C2 acts as... The auxiliary power supply transformer T1 is used as the input. The auxiliary power supply transformer T1 includes a first secondary winding and a second secondary winding. The first secondary winding and the second secondary winding are electrically isolated from each other. The first secondary winding of the auxiliary power supply transformer T1 is connected to the control board of the first power unit 21a so that the auxiliary power supply transformer T1 supplies auxiliary power to the control board of the first power unit 21a through the first secondary winding. The second secondary winding of the auxiliary power supply transformer T1 is connected to the control board of the second power unit 21b so that the auxiliary power supply transformer T1 supplies auxiliary power to the control board of the second power unit 21b through the second secondary winding.
[0018] Specifically, the rectifier unit is a rectifier bridge, which includes four diodes. The first AC input terminal of the rectifier bridge is connected to the AC input terminal of the first power unit 21a, the second AC input terminal of the rectifier bridge is connected to the AC output terminal of the second power unit 21b, the positive DC output terminal of the rectifier bridge is connected to the first terminal of the first capacitor C1, the negative DC output terminal of the rectifier bridge is connected to the second terminal of the third capacitor C3, and the two ends of the second capacitor C2 are respectively connected to the second terminal of the first capacitor C1 and the first terminal of the third capacitor C3.
[0019] Specifically, resistors are connected in parallel across the terminals of the first capacitor C1, the second capacitor C2, and the third capacitor C3. The resistor connected in parallel with the first capacitor C1 is denoted as R1, the resistor connected in parallel with the second capacitor C2 is denoted as R2, and the resistor connected in parallel with the third capacitor C3 is denoted as R3. Preferably, the resistance value of the resistor R3 connected in parallel with the third capacitor C3 is equal to the resistance value of the resistor R1 connected in parallel with the first capacitor C1, and the resistance value of the resistor R2 connected in parallel with the second capacitor C2 is less than the resistance value of the resistor R1 connected in parallel with the first capacitor C1.
[0020] Specifically, the capacitance values of the first capacitor C1, the second capacitor C2, and the third capacitor C3 are equal.
[0021] Preferably, one end of the primary winding of the auxiliary power supply transformer T1 can be connected to one end of the second capacitor C2 through a switching transistor. The switching transistor can be a transistor, with its collector connected to one end of the primary winding of the auxiliary power supply transformer T1 and its emitter connected to one end of the second capacitor C2.
[0022] Combination Figure 3 Specifically, the power unit 21 is an H-bridge power unit, which includes four IGBT transistors.
[0023] Specifically, the power device of this utility model includes a three-phase cascaded power module. Each phase cascaded power module includes several chain-connected power units and multiple chain-connected auxiliary power circuits. The AC sides of adjacent power units in each phase cascaded power module are connected in series. The chain-connected auxiliary power circuit is connected to the corresponding power unit so as to draw power from the AC side of the two power units in the same group, and then output two power supplies after conversion to provide auxiliary power to the two power units in the same group, so that the two cascaded power units can share a single auxiliary power supply circuit.
[0024] In summary, the auxiliary power circuit of this utility model, through setting up an auxiliary power supply circuit corresponding to and connected to the power units in a chain connection between two groups of power modules, draws power from the AC side of the two corresponding power units in the same group, and then outputs two power supplies after conversion to provide auxiliary power to the two corresponding power units in the same group. This allows two cascaded power units to share a single auxiliary power supply circuit, eliminating the need for isolation transformers for each power unit, reducing the demand for isolation transformers, lowering costs and space requirements, increasing the power density of the power modules, and reducing the need for maintenance in case of isolation transformer failure, thus lowering the failure rate. The power device of this utility model also has the above-mentioned functions.
[0025] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.
Claims
1. A chain-type power unit auxiliary power circuit, characterized in that, The power module is applied to a power module, which includes several chain-connected power units. The auxiliary power circuit of the chain-connected power unit includes multiple auxiliary power supply circuits. The power units are grouped in pairs. Each auxiliary power supply circuit corresponds to and is connected to each group of power units so as to draw power from the AC side of the two power units in the corresponding group, and after conversion and processing, supply auxiliary power to the two power units in the corresponding group.
2. The auxiliary power circuit of the chain-type power unit according to claim 1, characterized in that, The power unit includes a control board. The two power units in the same group are a first power unit and a second power unit. The AC output terminal of the first power unit is connected to the AC input terminal of the second power unit. The AC input terminal of the first power unit and the AC output terminal of the second power unit are connected to the input terminal of the auxiliary power supply circuit. The output terminal of the auxiliary power supply circuit is connected to the control board of the first power unit and the control board of the second power unit, respectively, to provide auxiliary power to the control board of the first power unit and the control board of the second power unit.
3. The auxiliary power circuit of the chain-type power unit according to claim 2, characterized in that, The auxiliary power supply circuit includes a rectifier unit, a capacitor bank, and an auxiliary power supply transformer. The input terminal of the rectifier unit serves as the input terminal of the auxiliary power supply circuit. The AC input terminal of the first power unit and the AC output terminal of the second power unit are connected to the input terminal of the rectifier unit. The output terminal of the rectifier unit is connected to the capacitor bank. The capacitor bank includes a first capacitor, a second capacitor, and a third capacitor connected in series. The two ends of the primary winding of the auxiliary power supply transformer are connected to the two ends of the second capacitor. The auxiliary power supply transformer includes a first secondary winding and a second secondary winding. The first secondary winding of the auxiliary power supply transformer is connected to the control board of the first power unit, and the second secondary winding of the auxiliary power supply transformer is connected to the control board of the second power unit.
4. The auxiliary power circuit of the chain-type power unit according to claim 3, characterized in that, The rectifier unit is a rectifier bridge. The first AC input terminal of the rectifier bridge is connected to the AC input terminal of the first power unit. The second AC input terminal of the rectifier bridge is connected to the AC output terminal of the second power unit. The positive DC output terminal of the rectifier bridge is connected to the first terminal of the first capacitor. The negative DC output terminal of the rectifier bridge is connected to the second terminal of the third capacitor. The two ends of the second capacitor are respectively connected to the second terminal of the first capacitor and the first terminal of the third capacitor.
5. The auxiliary power circuit of the chain-type power unit according to claim 3, characterized in that, A resistor is connected in parallel across the two ends of the first capacitor, the second capacitor, and the third capacitor.
6. The auxiliary power circuit of the chain-type power unit according to claim 5, characterized in that, The resistance value of the resistor connected in parallel with the two ends of the third capacitor is equal to the resistance value of the resistor connected in parallel with the two ends of the first capacitor, and the resistance value of the resistor connected in parallel with the two ends of the second capacitor is less than the resistance value of the resistor connected in parallel with the two ends of the first capacitor.
7. The auxiliary power circuit of the chain-type power unit according to claim 3, characterized in that, The capacitance values of the first capacitor, the second capacitor, and the third capacitor are equal.
8. The auxiliary power circuit of the chain-type power unit according to claim 3, characterized in that, One end of the primary winding of the auxiliary power supply transformer is connected to one end of the second capacitor via a switching transistor.
9. The auxiliary power circuit of the chain-type power unit according to claim 1, characterized in that, The power unit is an H-bridge power unit.
10. A power device, characterized in that, The system includes a three-phase cascaded power module, each phase cascaded power module including several chain-connected power units and multiple chain-connected auxiliary power circuits as described in any one of claims 1 to 9, the AC sides of adjacent power units in each phase cascaded power module are connected in series, and the chain-connected auxiliary power circuits are connected to the corresponding power units.