Alternating current and direct current hybrid dynamic voltage restorer, control method, device and medium
By employing a back-to-back NPC three-level circuit and an inductor-capacitor filter circuit in the DVR, combined with a carrier inversion stacking strategy, the problem of DVRs requiring two types of PCS is solved, enabling flexible switching and cost reduction of the AC/DC hybrid dynamic voltage restorer.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-16
- Publication Date
- 2026-04-14
AI Technical Summary
Existing DVRs require two different PCS to meet AC and DC power supply needs, resulting in inflexible application and adjustment, and high costs.
A back-to-back NPC three-level circuit combined with an inductor-capacitor filter circuit is adopted. A PWM signal is generated to control the IGBT device through a carrier inversion stacking strategy, so as to realize the flexible switching of the AC/DC hybrid dynamic voltage restorer.
It enables adaptation to both DC and AC input modes under the same circuit structure, reducing costs, decreasing equipment size, and improving flexibility and reliability.
Smart Images
Figure CN121863818A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of power supply technology, and in particular to an AC / DC hybrid dynamic voltage restorer, and its control method, device, and medium. Background Technology
[0002] In commercial space launch sites, it is crucial to protect equipment at core launch pads from power grid dips / ups / downs to prevent equipment shutdowns and launch aborts. Therefore, a Dynamic Voltage Restorer (DVR) is needed in the power supply system. This DVR can utilize supercapacitors as energy storage devices to power the load when powered by a single power source, and a backup AC power source when powered by multiple power sources. Thus, the DVR has both AC and DC input application scenarios.
[0003] Currently, DVRs utilize two types of power conversion systems (PCS): AC-to-DC and DC-to-DC, to achieve the aforementioned two application scenarios. However, because they employ two completely different PCS units, they cannot be flexibly applied and adjusted according to system changes, resulting in rigid field use and high costs.
[0004] Therefore, those skilled in the art urgently need a control method for an AC / DC hybrid dynamic voltage restorer to solve the problem caused by the current DVR requiring two different PCS to meet both AC and DC power supply requirements. Summary of the Invention
[0005] The purpose of this application is to provide an AC / DC hybrid dynamic voltage restorer, as well as a control method, device, and medium, to solve the problem caused by the current DVR requiring two different PCS to meet both AC and DC power supply needs.
[0006] To solve the above technical problems, this application provides a control method for an AC / DC hybrid dynamic voltage restorer, applied to a back-to-back NPC three-level circuit; wherein, the AC side of the back-to-back NPC three-level circuit is connected to an inductor-capacitor filter circuit;
[0007] The methods include:
[0008] Determine the system input mode; wherein, the system input mode includes: DC input mode and AC input mode;
[0009] If the system input mode is the DC input mode, then the following actions are executed: control the first and second switches of phase A to turn on, and the third and fourth switches to turn off; control the third switch of phase A to turn on, and the first, second, and fourth switches to turn off; control the first and second switches of phase C to turn off, and the third and fourth switches to turn on; control the first, third, and fourth switches of phase C to turn off, and the second switch to turn on; control the first and second switches of phase C to turn off, and the third and fourth switches to turn on; wherein, the first switch, the second switch, the third switch, and the fourth switch are four IGBT devices arranged in order from the positive to the negative terminal of the DC bus in each phase of the back-to-back NPC three-level circuit;
[0010] If the system input mode is the AC input mode, then the modulated wave is compared with the positive load wave to generate a PWM signal through a carrier inversion stacking strategy, and the PWM signal is used to control each IGBT device in the back-to-back NPC three-level circuit.
[0011] In an alternative embodiment, after determining the system input mode, the method further includes:
[0012] If the system input mode is the DC input mode, then switch the wiring on the other side of the connection between the inductor-capacitor filter circuit and the back-to-back NPC three-level circuit to the DC input wiring.
[0013] If the system input mode is the AC input mode, then the wiring on the other side of the connection between the inductor-capacitor filter circuit and the back-to-back NPC three-level circuit is switched to the AC input wiring.
[0014] In one optional embodiment, the step of generating a PWM signal by comparing the modulated wave with the positive load wave using a carrier inversion stacking strategy, and controlling each IGBT device in the back-to-back NPC three-level circuit using the PWM signal, includes:
[0015] During the positive half-cycle, the switching states of each IGBT device are controlled sequentially as follows: C state - 6 state - 3 state - 6 state - C state;
[0016] During the negative half-cycle, the switching states of each IGBT device are controlled sequentially as follows: 3-state - 6-state - C-state - 6-state - 3-state.
[0017] In an optional embodiment, the determination of the system input mode includes:
[0018] Detect the switching state of the jumper switch; wherein the switching state includes: a first state and a second state;
[0019] If the switch state of the jumper switch is the first state, then the system input mode is determined to be DC input mode;
[0020] If the jumper switch is in the second state, then the system input mode is determined to be AC input mode.
[0021] To address the aforementioned technical problems, this application also provides an AC / DC hybrid dynamic voltage restorer, comprising: a back-to-back NPC three-level circuit, an inductor-capacitor filter circuit, and a control module;
[0022] The AC side of the back-to-back NPC three-level circuit is connected to the first side of the inductor-capacitor filter circuit; the DC side of the back-to-back NPC three-level circuit serves as the output terminal of the AC / DC hybrid dynamic voltage restorer, which is used to connect to the load; the second side of the inductor-capacitor filter circuit serves as the input terminal of the AC / DC hybrid dynamic voltage restorer, which is used to connect to the supercapacitor or backup AC power supply.
[0023] The control module stores DC control strategy and AC control strategy. The control module is connected to the back-to-back NPC three-level circuit and is used to: execute the DC control strategy when the system input mode is DC input mode and execute the AC control strategy when the system input mode is AC input mode.
[0024] The DC control strategy includes: controlling the first and second switches of phase A to turn on, and the third and fourth switches to turn off; controlling the third switch of phase A to turn on, and the first, second, and fourth switches to turn off; controlling the first and second switches of phase C to turn off, and the third and fourth switches to turn on; controlling the first, third, and fourth switches of phase C to turn off, and the second switch to turn on; controlling the first and second switches of phase C to turn off, and the third and fourth switches to turn on; wherein the first, second, third, and fourth switches are four IGBT devices arranged in order from the positive to the negative terminal of the DC bus in each phase of the back-to-back NPC three-level circuit.
[0025] The AC control strategy includes: generating a PWM signal by comparing the modulated wave with the positive load wave through a carrier inversion stacking strategy, and controlling each IGBT device in the back-to-back NPC three-level circuit through the PWM signal.
[0026] In an optional embodiment, it further includes: a jumper switch connected to the control module;
[0027] The control module is further configured to: detect the switching state of the jumper switch; wherein the switching state includes: a first state and a second state; if the switching state of the jumper switch is the first state, then the system input mode is determined to be a DC input mode; if the switching state of the jumper switch is the second state, then the system input mode is determined to be an AC input mode.
[0028] In one optional embodiment, it further includes: a switching module;
[0029] The controlled terminal of the switching module is connected to the control module, the output terminal of the switching module is connected to the second side of the inductor-capacitor filter circuit, the first input terminal of the switching module is connected to the supercapacitor via a DC connection, and the second input terminal of the switching module is connected to the backup AC power supply via an AC connection.
[0030] The control module is also used to: control the switching module to select the first input terminal when the system input mode is DC input mode, and control the switching module to select the second input terminal when the system input mode is AC input mode.
[0031] To solve the above-mentioned technical problems, this application also provides a control device for an AC / DC hybrid dynamic voltage restorer, applied to a back-to-back NPC three-level circuit; wherein, the AC side of the back-to-back NPC three-level circuit is connected to an inductor-capacitor filter circuit;
[0032] The device includes:
[0033] A mode determination module is used to determine the system input mode; wherein, the system input mode includes: DC input mode and AC input mode;
[0034] A DC control module is configured to, if the system input mode is the DC input mode, execute the following actions: control the first and second switches of phase A to turn on, and the third and fourth switches to turn off; control the third switch of phase A to turn on, and the first, second, and fourth switches to turn off; control the first and second switches of phase C to turn off, and the third and fourth switches to turn on; control the first, third, and fourth switches of phase C to turn off, and the second switch to turn on; control the first and second switches of phase C to turn off, and the third and fourth switches to turn on; wherein the first, second, third, and fourth switches are four IGBT devices arranged in order from the positive to the negative terminal of the DC bus for each phase of the back-to-back NPC three-level circuit.
[0035] An AC control module is used to generate a PWM signal by comparing the modulated wave with the positive load wave through a carrier inversion stacking strategy if the system input mode is the AC input mode, and to control each IGBT device in the back-to-back NPC three-level circuit through the PWM signal.
[0036] To address the aforementioned technical problems, this application also provides a control device for an AC / DC hybrid dynamic voltage restorer, comprising:
[0037] Memory, used to store computer programs;
[0038] A processor is configured to execute the computer program to implement the control method for the AC / DC hybrid dynamic voltage restorer as described above.
[0039] To address the aforementioned technical problems, this application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the control method for the AC / DC hybrid dynamic voltage restorer as described above.
[0040] This application provides a control method for a hybrid AC / DC dynamic voltage restorer, which improves a back-to-back point-clamped (NPC) three-level circuit by adding an inductor-capacitor (LC) filter circuit to its AC side. This allows the circuit structure to operate in both AC-to-DC (AC-DC) and DC-to-DC (DC-DC) modes. The back-to-back NPC three-level circuit is a converter structure that supports AC-DC rectification mode output. A PWM signal is generated by comparing the modulated wave with the positive load wave using a carrier inversion stacking strategy. This PWM signal is then used to control the switching states of each IGBT device in the back-to-back NPC three-level circuit as required by the AC-DC rectification mode. For DC input mode, this method provides a specific control scheme comprising five steps, corresponding sequentially: a back-to-back NPC three-level circuit charges the positive energy storage capacitor in the LC filter circuit; the positive energy storage capacitor in the LC filter circuit charges the inductor; the back-to-back NPC three-level circuit charges the negative energy storage capacitor in the LC filter circuit; the negative energy storage capacitor charges the inductor; the negative energy storage capacitor and inductor charge the negative capacitor on the DC side; thus, DC input is achieved. Therefore, this scheme provides a circuit structure suitable for both DC and AC input applications. The appropriate control mode can be flexibly switched based on input requirements to meet the current power supply needs of DVRs. Furthermore, it eliminates the need for multiple different PCS units, resulting in lower costs.
[0041] The AC / DC hybrid dynamic voltage restorer and its control device, as well as the computer-readable storage medium provided in this application, correspond to the above-described method and have the same effect. Attached Figure Description
[0042] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0043] Figure 1 A circuit diagram of an AC / DC hybrid dynamic voltage restorer provided in an embodiment of the present invention;
[0044] Figure 2 A flowchart illustrating a control method for an AC / DC hybrid dynamic voltage restorer provided in an embodiment of the present invention;
[0045] Figure 3(a) is a schematic diagram of the first stage of DC input control provided in an embodiment of the present invention;
[0046] Figure 3(b) is a schematic diagram of the second stage of DC input control provided in an embodiment of the present invention;
[0047] Figure 3(c) is a schematic diagram of the third stage of DC input control provided in an embodiment of the present invention;
[0048] Figure 3(d) is a schematic diagram of the fourth stage of DC input control provided in an embodiment of the present invention;
[0049] Figure 3(e) is a schematic diagram of the fifth stage of DC input control provided in an embodiment of the present invention;
[0050] Figure 4 A control timing diagram for an AC input mode control method provided in an embodiment of the present invention;
[0051] Figure 5(a) is a schematic diagram of the first stage of the positive half-cycle of AC input control provided in an embodiment of the present invention;
[0052] Figure 5(b) is a schematic diagram of the second stage of the positive half-cycle of AC input control provided in an embodiment of the present invention;
[0053] Figure 5(c) is a schematic diagram of the third stage of the positive half-cycle of AC input control provided in an embodiment of the present invention;
[0054] Figure 5(d) is a schematic diagram of the fourth stage of the positive half-cycle of AC input control provided in an embodiment of the present invention. Detailed Implementation
[0055] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this application.
[0056] The core of this application is to provide an AC / DC hybrid dynamic voltage restorer, as well as a control method, device, and medium.
[0057] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0058] In commercial space launch sites, it is necessary to protect equipment in the core launch pad from power grid dips / ups / outages to prevent equipment shutdowns and launch cancellations caused by these issues. This problem is generally solved using a Dynamic Voltage Restorer (DVR).
[0059] There are typically three application scenarios in power supply systems: First, single-power supply, using supercapacitors for voltage sag protection; second, dual-power supply, using supercapacitors for voltage sag protection and switching between primary and backup power supplies; and third, dual-power supply, where the DVR uses the AC side of the backup power supply as its energy source to achieve voltage sag protection and switching between primary and backup power supplies. In other words, current requirements for DVRs include: the ability to use supercapacitors (DC input) as energy storage devices to power the load when powered by a single power source; and the ability to use a backup AC power source (AC input) as an energy source to power the load when powered by multiple power sources.
[0060] To address this, relevant technologies utilize two types of power conversion systems (PCS): AC-to-DC and DC-to-DC. However, these solutions are inflexible in adapting to system changes, resulting in rigid application in the field. Furthermore, using two different inverters incurs additional costs and increases the size of the DVR, hindering practical implementation.
[0061] To address the aforementioned problems, this application provides a control method for an AC / DC hybrid dynamic voltage restorer, applied to a back-to-back NPC three-level circuit. For example... Figure 1 As shown, the AC side of the back-to-back NPC three-level circuit is connected to an inductor-capacitor (LC) filter circuit. Figure 2 As shown, this method includes:
[0062] S1: Determine the system input mode; where the system input mode includes: DC input mode and AC input mode.
[0063] S2: If the system input mode is DC input mode, then execute the following: control the first and second switches of phase A to turn on, and the third and fourth switches to turn off; control the third switch of phase A to turn on, and the first, second, and fourth switches to turn off; control the first and second switches of phase C to turn off, and the third and fourth switches to turn on; control the first, third, and fourth switches of phase C to turn off, and the second switch to turn on; wherein, the first, second, third, and fourth switches are four insulated-gate bipolar transistor (IGBT) devices arranged in order from the positive to the negative terminal of the DC bus in each phase of a back-to-back NPC three-level circuit. Figure 1 The three phases A, B, and C each have four corresponding IGBT devices T1~T4.
[0064] S3: If the system input mode is AC input mode, the modulated wave is compared with the positive load wave to generate a PWM signal through the carrier inversion stacking strategy, and the PWM signal is used to control each IGBT device in the back-to-back NPC three-level circuit.
[0065] It should be noted that the back-to-back NPC three-level circuit is a circuit that supports AC / DC mode. This application adds an LC filter circuit to the AC side of the back-to-back NPC three-level circuit, enabling it to also support DC / DC mode operation. The specific control scheme, namely step S2, includes the following five stages:
[0066] 1. Charge the positive energy storage capacitor (C1):
[0067] At this time, the current flow is as shown in Figure 3(a). At this time, the first switch T1-A and the second switch T2-A of phase A are turned on, and the third switch T3-A and the fourth switch T4-A are turned off.
[0068] 2. The positive energy storage capacitor (C1) charges the inductor (L1):
[0069] At this time, the current flow is as shown in Figure 3(b). At this time, the first switch T1-A, the second switch T2-A, and the fourth switch T4-A of phase A are turned off, the third switch T3-A is turned on, and the current also flows through diode D2. Figure 1 Diodes D1 to D6 are clamping diodes for the positive and negative terminals of the three-phase DC bus, respectively.
[0070] 3. Charge the negative terminal energy storage capacitor (C2):
[0071] At this time, the current flow is as shown in Figure 3(c). At this time, the first switch T1-C and the second switch T2-C of phase C are turned off, and the third switch T3-C and the fourth switch T4-C are turned on.
[0072] 4. The negative energy storage capacitor (C2) charges the inductor (L3):
[0073] At this time, the current flow is as shown in Figure 3(d). At this time, the first switch T1-C, the third switch T3-C, and the fourth switch T4-C of phase C are turned off, the second switch T2-C is turned on, and the current also flows through diode D5.
[0074] 5. The negative energy storage capacitor (C2) + inductor (L3) charges the DC side negative capacitor (C4):
[0075] At this time, the current flow is as shown in Figure 3(e). At this time, the first switch T1-C and the second switch T2-C of phase C are turned off, and the third switch T3-C and the fourth switch T4-C are turned on.
[0076] Based on stages 1 to 5 above, a DC power supply input for one control cycle is completed.
[0077] Step S3 refers to the AC control strategy when the input is determined to be AC. Using a carrier inversion stacking strategy, the modulated wave is compared with the positive load wave to generate a PWM signal to control the IGBT operation. The switching state timing of the IGBT device is as follows: Figure 4 As shown.
[0078] Furthermore, in AC control, a complete control cycle can be divided into a positive half-cycle and a negative half-cycle. This embodiment provides a further AC control scheme: in the positive half-cycle, the switching states of each IGBT device are controlled sequentially as follows: C state - 6 state - 3 state - 6 state - C state; in the negative half-cycle, the switching states of each IGBT device are controlled sequentially as follows: 3 state - 6 state - C state - 6 state - 3 state.
[0079] Specifically, taking the positive half-cycle as an example, it includes the following four stages:
[0080] 1. C-state to 6-state: As shown in Figure 5(a), the current flows in the direction of the red directed line segment in Figure 5(a), which is: P-0.
[0081] 2. 6-state to 3-state: As shown in Figure 5(b), the current flows in the direction of the red directed line segment in Figure 5(b), which is: 0-N.
[0082] 3. 3-6 states: As shown in Figure 5(c), the current flows in the direction shown by the red directed line segment in Figure 5(c), which is N-0.
[0083] 4. 6-C state: As shown in Figure 5(d), the current flows in the direction of the red directed line segment in Figure 5(d), which is: 0-P.
[0084] For the negative half-cycle, the control sequence of its switching states is: state 3-state 6-state C-state 6-state 3. It is easy to see that the switching states involved in the negative half-cycle and the positive half-cycle are the same, the only difference being the order. Therefore, the specific control of the negative half-cycle can be found in the above explanation of the positive half-cycle, as well as Figures 5(a) to 5(d), which will not be repeated here.
[0085] As described above, this application provides a solution that enables a hybrid AC / DC dynamic voltage restorer to adapt to both DC and AC input application scenarios through a single circuit structure. By connecting an LC filter circuit to the AC side of a back-to-back NPC three-level circuit, it can support both AC / DC and DC / DC modes. After determining the corresponding system input mode, the input requirements can be met by switching the appropriate control method. This protects downstream load devices from the effects of grid dips / boosts / interruptions, avoiding serious losses. This solution requires only one circuit structure to meet both input modes, offering flexible and reliable implementation, lower cost, and smaller circuit area, better meeting the needs of practical application scenarios.
[0086] on the other hand, Figure 1 Ports 1-3 are for connecting to supercapacitors or backup AC power supplies, and there are two wiring schemes: AC wiring (ABC) and DC wiring (P0N). Figure 1 Ports 4 to 6 are connected to the load to provide DC power, corresponding to a DC connection (PON) scheme. Based on this, this embodiment also provides another optional embodiment, in which the method, after step S1, further includes:
[0087] S41: If the system input mode is DC input mode, switch the wiring on the other side of the connection between the inductor-capacitor filter circuit and the back-to-back NPC three-level circuit to DC input wiring. That is... Figure 1 Wiring scheme for switching ports 1-3 to P0N.
[0088] S42: If the system input mode is AC input mode, switch the wiring on the other side of the connection between the inductor-capacitor filter circuit and the back-to-back NPC three-level circuit to AC input wiring. That is... Figure 1 Switch the wiring scheme of ports 1-3 to ABC.
[0089] Therefore, this embodiment only requires changing the wiring scheme on one side when switching the input mode of the DVR device, without changing the circuit structure or adding new control logic, making this solution easier to implement.
[0090] Furthermore, regarding how to determine the system input mode in step S1 above, it can be determined through external command input or obtained through communication with the host computer. This embodiment also provides another optional implementation scheme, where step S1 specifically involves:
[0091] S11: Detect the switching status of the jumper switch.
[0092] The switch states include a first state and a second state. The first state and the second state correspond to the open state (1) and the closed state (0) of the jumper switch, but the specific correspondence is not limited in this embodiment.
[0093] S12: If the jumper switch is in the first state, then the system input mode is determined to be DC input mode.
[0094] S13: If the switch state of the jumper switch is the second state, then the system input mode is determined to be AC input mode.
[0095] This embodiment determines the system input mode by the switching state of the jumper switch, without the need to introduce complex hardware structures or communication lines, making it simple, convenient, and easy to implement in practical engineering.
[0096] In the above embodiments, a control method for an AC / DC hybrid dynamic voltage restorer has been described in detail. This method is based on an improved circuit structure provided in this application, specifically, an inductor-capacitor filter circuit is connected to the AC side of a back-to-back NPC three-level circuit. In this regard, this application also provides an embodiment of an AC / DC hybrid dynamic voltage restorer. For example... Figure 1 As shown, an AC / DC hybrid dynamic voltage restorer includes: a back-to-back NPC three-level circuit, an inductor-capacitor filter circuit, and a control module.
[0097] The AC side of the back-to-back NPC three-level circuit is connected to the first side of the inductor-capacitor filter circuit; the DC side of the back-to-back NPC three-level circuit serves as the output terminal of the AC / DC hybrid dynamic voltage restorer, which is used to connect to the load; the second side of the inductor-capacitor filter circuit serves as the input terminal of the AC / DC hybrid dynamic voltage restorer, which is used to connect to the supercapacitor or backup AC power supply.
[0098] The control module stores DC control strategies and AC control strategies. The control module is connected to a back-to-back NPC three-level circuit and is used to execute the DC control strategy when the system input mode is DC input mode and execute the AC control strategy when the system input mode is AC input mode.
[0099] The DC control strategy includes: controlling the first and second switches of phase A to turn on, and the third and fourth switches to turn off; controlling the third switch of phase A to turn on, and the first, second, and fourth switches to turn off; controlling the first and second switches of phase C to turn off, and the third and fourth switches to turn on; controlling the first, third, and fourth switches of phase C to turn off, and the second switch to turn on; controlling the first and second switches of phase C to turn off, and the third and fourth switches to turn on; wherein the first, second, third, and fourth switches are four IGBT devices arranged in a back-to-back NPC three-level circuit according to the order from the positive to the negative terminal of the DC bus.
[0100] The AC control strategy includes: using a carrier inversion stacking strategy to compare the modulated wave with the positive load wave to generate a PWM signal, and using the PWM signal to control each IGBT device in the back-to-back NPC three-level circuit.
[0101] The implementation of DC / DC and AC / DC functions by the hybrid dynamic voltage restorer provided in this embodiment, and the control of the switching states of the corresponding IGBT devices, have been explained in detail in the embodiments of the method section above. Therefore, this embodiment will not repeat the details here; for specific implementation schemes, please refer to the embodiments of the method section above.
[0102] The control module mentioned above can be implemented using any device with logic processing capabilities in the AC / DC hybrid dynamic voltage restorer, such as a field-programmable gate array (FPGA), a programmable logic array (PLA), or a microcontroller unit (MCU).
[0103] On the other hand, one optional embodiment of the above method is to determine the system input mode through a jumper switch. Based on this, this embodiment provides an embodiment corresponding to an AC / DC hybrid dynamic voltage restorer. The AC / DC hybrid dynamic voltage restorer further includes a jumper switch connected to a control module. The control module is further configured to: detect the switching state of the jumper switch; wherein the switching state includes a first state and a second state; if the switching state of the jumper switch is the first state, then the system input mode is determined to be a DC input mode; if the switching state of the jumper switch is the second state, then the system input mode is determined to be an AC input mode.
[0104] Specifically, when the control module described above is implemented using an FPGA, the jumper switch can be located on the same motherboard as the FPGA. The FPGA is directly connected to the jumper switch to detect its on / off state, thereby determining the current system input mode. Based on this embodiment, the system input mode can be switched by changing the on / off state of the jumper switch; the solution is simple and easy to implement.
[0105] On the other hand, this embodiment also provides another optional solution. The above-mentioned AC / DC hybrid dynamic voltage restorer further includes: a switching module; the controlled terminal of the switching module is connected to the control module, the output terminal of the switching module is connected to the second side of the inductor-capacitor filter circuit, the first input terminal of the switching module is connected to the supercapacitor via a DC connection, and the second input terminal of the switching module is connected to the backup AC power supply via an AC connection; the control module is also used to: control the switching module to select the first input terminal when the system input mode is DC input mode, and control the switching module to select the second input terminal when the system input mode is AC input mode. The switching module can be implemented using a multiplexer or other selection device; this embodiment does not limit the specific type of switching module.
[0106] This embodiment, based on the switching module configuration, provides two access paths for the second side of the LC filter circuit, i.e., the side connected to the power supply (the other side relative to the load). The first input terminal of the switching module is connected to the supercapacitor using a DC connection scheme (PON). The second input terminal of the switching module is connected to the AC backup power supply using an AC / DC connection scheme (ABC). The control module can then control which input terminal the switching module selects, enabling the switching of the DVR's internal power supply between the supercapacitor and the AC backup power supply, as well as the switching of the wiring scheme between a straight-line connection scheme and an AC connection scheme. This switching does not require manual intervention, further improving switching efficiency, ensuring power switching reliability, and reducing implementation difficulty.
[0107] In the above embodiments, a control method for an AC / DC hybrid dynamic voltage restorer has been described in detail. This application also provides an embodiment corresponding to a control device for an AC / DC hybrid dynamic voltage restorer. It should be noted that this application describes the device portion of the embodiment from two perspectives: one based on functional modules and the other based on hardware.
[0108] From the perspective of functional modules, this embodiment provides a control device for an AC / DC hybrid dynamic voltage restorer, applied to a back-to-back NPC three-level circuit; wherein, the AC side of the back-to-back NPC three-level circuit is connected to an inductor-capacitor filter circuit. The device includes:
[0109] The mode determination module is used to determine the system input mode; the system input modes include: DC input mode and AC input mode.
[0110] The DC control module, if the system input mode is DC input mode, performs the following actions: controlling the first and second switches of phase A to turn on, and the third and fourth switches to turn off; controlling the third switch of phase A to turn on, and the first, second, and fourth switches to turn off; controlling the first and second switches of phase C to turn off, and the third and fourth switches to turn on; controlling the first, third, and fourth switches of phase C to turn off, and the second switch to turn on; controlling the first and second switches of phase C to turn off, and the third and fourth switches to turn on; wherein the first, second, third, and fourth switches are four IGBT devices arranged in a back-to-back NPC three-level circuit according to the order from the positive to the negative terminal of the DC bus.
[0111] The AC control module is used to generate a PWM signal by comparing the modulated wave with the positive load wave through a carrier inversion stacking strategy if the system input mode is AC input mode, and then control each IGBT device in the back-to-back NPC three-level circuit through the PWM signal.
[0112] Since the embodiments of the apparatus and the embodiments of the method correspond to each other, please refer to the description of the embodiments of the method for the embodiments of the apparatus, which will not be repeated here.
[0113] Another embodiment of this application provides a control device for an AC / DC hybrid dynamic voltage restorer, comprising: a memory for storing a computer program; and a processor for executing the computer program to implement the steps of the control method for an AC / DC hybrid dynamic voltage restorer as described in the above embodiment.
[0114] The control device for an AC / DC hybrid dynamic voltage restorer provided in this embodiment can include, but is not limited to, mobile terminals, personal computers, workstations, etc. The processor can include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor can be implemented using at least one hardware form selected from Digital Signal Processor (DSP), Field-Programmable Gate Array (FPGA), and Programmable Logic Array (PLA). The processor can also include a main processor and a coprocessor. The main processor, also known as the Central Processing Unit (CPU), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor can integrate a Graphics Processing Unit (GPU), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, the processor can also include an Artificial Intelligence (AI) processor, which is used to handle computational operations related to machine learning.
[0115] The memory may include one or more computer-readable storage media, which may be non-transitory. The memory may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In this embodiment, the memory is used to store at least the following computer program, which, after being loaded and executed by a processor, is capable of implementing the relevant steps of the control method for an AC / DC hybrid dynamic voltage restorer disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory may also include an operating system and data, and the storage method may be temporary or permanent storage. The operating system may include Windows, Unix, Linux, etc. The data may include, but is not limited to, a control method for an AC / DC hybrid dynamic voltage restorer.
[0116] In some embodiments, the control device of an AC / DC hybrid dynamic voltage restorer may further include a display screen, an input / output interface, a communication interface, a power supply, and a communication bus.
[0117] This application provides a control device for an AC / DC hybrid dynamic voltage restorer, which includes a memory and a processor. When the processor executes a program stored in the memory, it can implement the following method: a control method for an AC / DC hybrid dynamic voltage restorer.
[0118] Finally, this application also provides an embodiment corresponding to a computer-readable storage medium. The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps described in the above method embodiments.
[0119] It is understood that if the methods in the above embodiments are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and executes all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0120] The above provides a detailed description of an AC / DC hybrid dynamic voltage restorer, control method, apparatus, and medium provided in this application. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of this application.
[0121] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
Claims
1. A control method for an AC / DC hybrid dynamic voltage restorer, characterized in that, It is applied to a back-to-back NPC three-level circuit; wherein, the AC side of the back-to-back NPC three-level circuit is connected to an inductor-capacitor filter circuit; The methods include: Determine the system input mode; wherein, the system input mode includes: DC input mode and AC input mode; If the system input mode is the DC input mode, then the following actions are executed: control the first and second switches of phase A to turn on, and the third and fourth switches to turn off; control the third switch of phase A to turn on, and the first, second, and fourth switches to turn off; control the first and second switches of phase C to turn off, and the third and fourth switches to turn on; control the first, third, and fourth switches of phase C to turn off, and the second switch to turn on; control the first and second switches of phase C to turn off, and the third and fourth switches to turn on; wherein, the first switch, the second switch, the third switch, and the fourth switch are four IGBT devices arranged in order from the positive to the negative terminal of the DC bus in each phase of the back-to-back NPC three-level circuit; If the system input mode is the AC input mode, then the modulated wave is compared with the positive load wave to generate a PWM signal through a carrier inversion stacking strategy, and the PWM signal is used to control each IGBT device in the back-to-back NPC three-level circuit.
2. The control method for the AC / DC hybrid dynamic voltage restorer according to claim 1, characterized in that, After determining the system input mode, the following is also included: If the system input mode is the DC input mode, then switch the wiring on the other side of the connection between the inductor-capacitor filter circuit and the back-to-back NPC three-level circuit to the DC input wiring. If the system input mode is the AC input mode, then the wiring on the other side of the connection between the inductor-capacitor filter circuit and the back-to-back NPC three-level circuit is switched to the AC input wiring.
3. The control method for the AC / DC hybrid dynamic voltage restorer according to claim 1, characterized in that, The step of generating a PWM signal by comparing the modulated wave with the positive load wave through a carrier inversion stacking strategy, and controlling each IGBT device in the back-to-back NPC three-level circuit through the PWM signal includes: During the positive half-cycle, the switching states of each IGBT device are controlled sequentially as follows: C state - 6 state - 3 state - 6 state - C state; During the negative half-cycle, the switching states of each IGBT device are controlled sequentially as follows: 3-state - 6-state - C-state - 6-state - 3-state.
4. The control method for the AC / DC hybrid dynamic voltage restorer according to any one of claims 1 to 3, characterized in that, The determination of the system input mode includes: Detect the switching state of the jumper switch; wherein the switching state includes: a first state and a second state; If the switch state of the jumper switch is the first state, then the system input mode is determined to be DC input mode; If the jumper switch is in the second state, then the system input mode is determined to be AC input mode.
5. A hybrid AC / DC dynamic voltage restorer, characterized in that, include: Back-to-back NPC three-level circuit, inductor-capacitor filter circuit and control module; The AC side of the back-to-back NPC three-level circuit is connected to the first side of the inductor-capacitor filter circuit; the DC side of the back-to-back NPC three-level circuit serves as the output terminal of the AC / DC hybrid dynamic voltage restorer, which is used to connect to the load; the second side of the inductor-capacitor filter circuit serves as the input terminal of the AC / DC hybrid dynamic voltage restorer, which is used to connect to the supercapacitor or backup AC power supply. The control module stores DC control strategy and AC control strategy. The control module is connected to the back-to-back NPC three-level circuit and is used to: execute the DC control strategy when the system input mode is DC input mode and execute the AC control strategy when the system input mode is AC input mode. The DC control strategy includes: controlling the first and second switches of phase A to turn on, and the third and fourth switches to turn off; controlling the third switch of phase A to turn on, and the first, second, and fourth switches to turn off; controlling the first and second switches of phase C to turn off, and the third and fourth switches to turn on; controlling the first, third, and fourth switches of phase C to turn off, and the second switch to turn on; controlling the first and second switches of phase C to turn off, and the third and fourth switches to turn on; wherein the first, second, third, and fourth switches are four IGBT devices arranged in order from the positive to the negative terminal of the DC bus in each phase of the back-to-back NPC three-level circuit. The AC control strategy includes: generating a PWM signal by comparing the modulated wave with the positive load wave through a carrier inversion stacking strategy, and controlling each IGBT device in the back-to-back NPC three-level circuit through the PWM signal.
6. The AC / DC hybrid dynamic voltage restorer according to claim 5, characterized in that, Also includes: The jumper switch connected to the control module; The control module is further configured to: detect the switching state of the jumper switch; wherein the switching state includes: a first state and a second state; if the switching state of the jumper switch is the first state, then the system input mode is determined to be a DC input mode; if the switching state of the jumper switch is the second state, then the system input mode is determined to be an AC input mode.
7. The AC / DC hybrid dynamic voltage restorer according to claim 5 or 6, characterized in that, Also includes: Switch modules; The controlled terminal of the switching module is connected to the control module, the output terminal of the switching module is connected to the second side of the inductor-capacitor filter circuit, the first input terminal of the switching module is connected to the supercapacitor via a DC connection, and the second input terminal of the switching module is connected to the backup AC power supply via an AC connection. The control module is also used to: control the switching module to select the first input terminal when the system input mode is DC input mode, and control the switching module to select the second input terminal when the system input mode is AC input mode.
8. A control device for an AC / DC hybrid dynamic voltage restorer, characterized in that, It is applied to a back-to-back NPC three-level circuit; wherein, the AC side of the back-to-back NPC three-level circuit is connected to an inductor-capacitor filter circuit; The device includes: A mode determination module is used to determine the system input mode; wherein, the system input mode includes: DC input mode and AC input mode; A DC control module is configured to, if the system input mode is the DC input mode, execute the following actions: control the first and second switches of phase A to turn on, and the third and fourth switches to turn off; control the third switch of phase A to turn on, and the first, second, and fourth switches to turn off; control the first and second switches of phase C to turn off, and the third and fourth switches to turn on; control the first, third, and fourth switches of phase C to turn off, and the second switch to turn on; control the first and second switches of phase C to turn off, and the third and fourth switches to turn on; wherein the first, second, third, and fourth switches are four IGBT devices arranged in order from the positive to the negative terminal of the DC bus for each phase of the back-to-back NPC three-level circuit. An AC control module is used to generate a PWM signal by comparing the modulated wave with the positive load wave through a carrier inversion stacking strategy if the system input mode is the AC input mode, and to control each IGBT device in the back-to-back NPC three-level circuit through the PWM signal.
9. A control device for an AC / DC hybrid dynamic voltage restorer, characterized in that, include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the steps of the control method for the AC / DC hybrid dynamic voltage restorer as described in any one of claims 1 to 4.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the control method for the AC / DC hybrid dynamic voltage restorer as described in any one of claims 1 to 4.