Transient voltage control apparatus and method for inverter

Abstract

A transient voltage control apparatus for an inverter, relating to the technical field of circuits. The apparatus comprises: a sampling circuit (104), used for collecting the voltage at an output end of an inverter; and a DSP (103), used for acquiring the voltage at the output end of the inverter, determining a target voltage component on the basis of the voltage at the output end of the inverter, when the target voltage component is greater than a first threshold value, controlling, by means of a driving circuit (102), a bleeder circuit (101) to discharge the voltage at the output end of the inverter and generating overvoltage flag data for representing a trigger transient voltage of the inverter, and in response to the overvoltage flag data for representing the trigger transient voltage of the inverter, controlling the inverter to be in a non-operating state so as to control the transient voltage. The present application can rapidly adjust voltages at output ends of inverters to target states.

Description

Transient voltage control device and method for inverter

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 25, 2023, with application number 202311082667.6 and invention name “Transient voltage control device and method for inverter”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of circuit technology, and in particular to a transient voltage control device and method for an inverter. Background Art

[0003] An inverter is a power electronic device used to convert direct current (DC) into alternating current (AC). For example, the inverter in a solar photovoltaic system converts the DC power generated by solar panels into AC power to supply electricity to homes or industrial facilities. When the inverter's output port is properly connected to the grid and the inverter is operating normally, grid-connection regulations in some countries require that, if the mains power outage or the circuit breaker connected to the mains power suddenly disconnects, the inverter's output voltage must drop to zero within a specified timeframe to protect the load connected to the inverter's AC port. This drop time must meet regulatory requirements. To meet transient voltage requirements, a common approach is to sample and determine the mains voltage at the inverter's output port in software. When an abnormal mains voltage is detected, software control logic is used to shut down the inverter's power output, allowing the inverter's output voltage to drop rapidly. However, in practice, relying solely on software to shut down the inverter's power output often makes it difficult to achieve the transient voltage drop required for testing.

[0004] Summary of the Invention

[0005] The transient voltage control device and method for an inverter provided by the embodiments of the present invention can quickly adjust the transient voltage of the inverter at least by combining software and hardware.

[0006] According to one aspect of the present application, a transient voltage control device for an inverter is provided, comprising: a discharge circuit, a drive circuit, a sampling circuit, and a DSP processor; the discharge circuit is disposed at the output of the inverter; the DSP processor is electrically connected to the discharge circuit via the drive circuit; the DSP processor is electrically connected to the output of the inverter via the sampling circuit; the sampling circuit is configured to sample the voltage at the inverter output; the DSP processor is configured to obtain the voltage at the inverter output and determine a target voltage component based on the voltage at the inverter output. The DSP processor is further configured to, when the target voltage component is greater than a first threshold, control the discharge circuit via the drive circuit to discharge the voltage at the inverter output, generate overvoltage flag data for characterizing a transient voltage triggered by the inverter, and, in response to the overvoltage flag data for characterizing a transient voltage triggered by the inverter, control the inverter to be in a non-operating state to control the transient voltage.

[0007] The DSP processor is further configured to control the discharge circuit to stop discharging the voltage at the output end of the inverter through the drive circuit when the target voltage component is less than a second threshold value, and to generate overvoltage flag data for characterizing that the inverter has not triggered a transient voltage, and to control the inverter to be in an operating state in response to the overvoltage flag data for characterizing that the inverter has not triggered a transient voltage, so as to control the transient voltage; wherein the second threshold value is less than the first threshold value.

[0008] According to another aspect of the present application, a method for controlling transient voltage of an inverter is provided, which is applied to a DSP processor. The method includes: collecting the voltage at the output end of the inverter through a sampling circuit; determining a target voltage component based on the voltage at the output end of the inverter; when the target voltage component is greater than a first threshold, controlling the discharge circuit through a drive circuit to discharge the voltage at the output end of the inverter, generating overvoltage flag data for characterizing a transient voltage triggered by the inverter, and controlling the inverter to be in a non-operating state in response to the overvoltage flag data for characterizing the transient voltage triggered by the inverter; or, when the target voltage component is less than a second threshold, controlling the discharge circuit through the drive circuit to stop discharging the voltage at the output end of the inverter, generating overvoltage flag data for characterizing a transient voltage not triggered by the inverter, and controlling the inverter to be in an operating state in response to the overvoltage flag data for characterizing the transient voltage not triggered by the inverter; wherein the second threshold is less than the first threshold.

[0009] According to another aspect of the present application, an electronic device is provided, comprising: a processor; and a memory storing a program, wherein the program comprises instructions, which, when executed by the processor, enable the processor to perform the above method.

[0010] According to another aspect of the present application, a non-transitory computer-readable storage medium storing computer instructions is further provided, wherein the computer instructions are used to enable the computer to execute the steps of the above method.

[0011] Beneficial effects of the embodiments of the present invention:

[0012] An embodiment of the present invention includes a discharge circuit, a drive circuit, a sampling circuit, and a DSP processor; the discharge circuit is disposed at the output of an inverter; the DSP processor is electrically connected to the discharge circuit via the drive circuit; and the DSP processor is electrically connected to the output of the inverter via the sampling circuit. Therefore, based on the sampling circuit and the DSP processor, the embodiment of the present invention can acquire the voltage at the output of the inverter in real time, determine a target voltage component based on the voltage at the output of the inverter, generate a control signal and overvoltage flag data based on the target voltage component and a preset voltage threshold, and then, using the drive circuit, adjust the control signal to a target control signal, which is then sent to the discharge circuit. The discharge circuit controls the transient voltage from a hardware perspective according to the target control signal, and uses the DSP processor to control the operating state of the inverter according to the overvoltage flag data, thereby controlling the transient voltage from a software perspective. The embodiment of the present invention achieves transient voltage control based on a combination of software and hardware dimensions, thereby quickly adjusting the output voltage of the inverter to a target state within a certain time range.

[0013] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below so that other features, objects, and advantages of the invention are more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be derived from these drawings without inventive effort.

[0015] FIG1 is a structural block diagram of a transient voltage control device for an inverter according to an embodiment of the present invention;

[0016] FIG2 is a schematic structural diagram of a transient voltage control device for an inverter;

[0017] FIG3 is a schematic structural diagram of an electronic device according to this embodiment;

[0018] FIG4 is a schematic diagram of an implementation of a transient voltage control device for an inverter according to an embodiment of the present invention;

[0019] FIG5 is a circuit structure diagram of a transient voltage control device for an inverter according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The following describes embodiments of the present invention in more detail with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0021] To quickly adjust transient voltages to the ideal state, a hardware bleeder circuit is added to the inverter system. As shown in Figure 2, the DC / AC circuit represents the inverter. The bleeder circuit is placed at the inverter's output. When an abnormal transient mains voltage is detected, software controls the inverter output, shutting down the inverter. Simultaneously, the bleeder circuit bleeds off the voltage at the inverter output. When the hardware bleeder circuit is added, if it remains operational, it will cause power loss. Therefore, when addressing transient voltages, if the software and hardware solutions operate independently, it will be difficult to ensure that the transient voltage meets test requirements.

[0022] Therefore, an embodiment of the present invention provides a device and method for controlling transient voltage of an inverter. The device can control the transient voltage of the inverter by combining software and hardware based on a simple circuit structure.

[0023] In an embodiment of the present invention, a transient voltage control device for an inverter is provided. FIG1 is a structural block diagram of the transient voltage control device for an inverter according to the embodiment of the present application. FIG4 is an implementation schematic diagram of the transient voltage control device for an inverter according to the embodiment of the present application. The structures involved in FIG1 and FIG4 are described below.

[0024] The transient voltage control device includes a discharge circuit 101, a drive circuit 102, a sampling circuit 104, and a DSP processor 103. The discharge circuit is disposed at the output of the inverter; the DSP processor is electrically connected to the discharge circuit via the drive circuit; and the DSP (Digital Signal Processor) processor is electrically connected to the output of the inverter via the sampling circuit. The sampling circuit is used to collect the voltage at the inverter output. The DSP processor is used to obtain the voltage at the inverter output, determine a target voltage component based on the voltage at the inverter output, and then control the drive circuit based on the target voltage component and a preset voltage threshold to control the operating state of the discharge circuit via the drive circuit. Furthermore, overvoltage flag data is generated based on the target voltage component and the preset voltage threshold, and the operating state of the inverter is controlled based on the overvoltage flag data to control the transient voltage.

[0025] Specifically, in an embodiment of the present invention, the output of the inverter is connected to a power system or power grid, thereby providing AC power to the power system or power grid. When a voltage anomaly occurs in the power system or power grid, a transient voltage is triggered, resulting in a transient overvoltage. Transient voltage refers to short-term, non-periodic voltage fluctuations that occur in the power system. It is usually caused by sudden power failures, switching operations of electrical equipment, lightning strikes, etc. It should be noted that transient voltage can be divided into two types: positive transient voltage and negative transient voltage. Positive transient voltage refers to a moment when the voltage suddenly increases, while negative transient voltage refers to a moment when the voltage suddenly decreases. These transient voltages are typically short-lived, generally ranging from a few microseconds to a few milliseconds. Transient voltage may have some adverse effects on the power system and electrical equipment. For example, it may cause overvoltage damage to equipment, arc discharge, and malfunction of electrical equipment.

[0026] The discharge circuit is arranged at the output end of the inverter, and the DSP processor is electrically connected to the discharge circuit through the drive circuit, so that when a transient voltage is triggered, the discharge circuit can discharge the transient voltage according to the target control signal sent by the DSP processor through the drive circuit.

[0027] The DSP processor is electrically connected to the output of the inverter via the sampling circuit. The sampling circuit can collect the voltage at the inverter output in real time, so that the DSP processor can read the voltage at the inverter output via the sampling circuit. After obtaining the real-time collected voltage at the inverter output, the DSP processor processes the voltage at the inverter output and adjusts it to a value that is beneficial for subsequent calculation steps. For example, if the collected voltage at the inverter output is an AC signal, the AC signal is converted into a DC signal, and a target voltage component for calculation is obtained from the DC signal. In other words, the target voltage component is determined based on the voltage at the inverter output.

[0028] The preset voltage threshold can be set based on actual needs or experience, and more than one value can be set as the preset voltage threshold, which is not specifically limited in the embodiments of the present invention. By assigning different values ​​to the overvoltage flag data, it can be indicated whether the transient voltage of the inverter is in a triggered state. That is, the overvoltage flag data is used to indicate the transient voltage trigger state of the inverter.

[0029] It should be noted that overvoltage flag data can be implemented by setting a variable and assigning a value to the variable. By modifying the value of the variable, the overvoltage flag data can be modified. For example, setting the variable "OvpFlag" and assigning it a value of "1" or "0" will use "OvpFlag" to represent the overvoltage flag data.

[0030] When its value is "1", it indicates that the transient voltage trigger state of the inverter is triggered, that is, it indicates that the inverter is transient overvoltage, which means that the overvoltage flag data generated at this time is used to indicate the inverter trigger transient voltage.

[0031] When its value is "0," the inverter's transient voltage trigger state is not triggered, indicating that the inverter has not experienced a transient overvoltage. This indicates that the generated data is overvoltage flag data indicating that the inverter has not triggered a transient voltage. Furthermore, the initial value of the variable representing the overvoltage flag data can be set based on actual needs and is not specifically limited in this embodiment of the present invention. For example, the initial value can be null.

[0032] Based on the target voltage component, the preset voltage threshold, and the overvoltage flag data, the real-time transient voltage condition at the inverter's output can be understood, and based on the specific situation, a corresponding control signal can be generated and the overvoltage flag data adjusted. For example, if the presence of a transient voltage at the inverter's output is determined based on the target voltage component and the preset voltage threshold, a corresponding control signal can be generated to eliminate the transient voltage. Furthermore, if the overvoltage flag data does not match the current state, for example, the overvoltage flag data may indicate that the inverter's transient voltage is in an untriggered state or the overvoltage flag data is an initial value, the value of the variable representing the overvoltage flag data is modified, and the modified value is used to indicate that the inverter's transient voltage is in a triggered state. By modifying the value of the overvoltage flag data, the overvoltage flag data can indicate the latest state of the transient voltage in real time. Thereafter, the control signal is sent to the drive circuit.

[0033] It's important to note that a DSP processor is a microprocessor specifically designed for digital signal processing. It features efficient algorithm execution and a specialized instruction set, enabling rapid processing of digital signals such as audio, video, and images. DSP processors typically offer high-speed data transmission and processing capabilities, as well as multi-channel parallel processing, enabling real-time processing of large amounts of data. DSP processors are characterized by high performance, low power consumption, low latency, high precision, and programmability. They can be programmed through software to implement various digital signal processing algorithms, offering high flexibility and scalability.

[0034] Furthermore, the driving circuit is used to receive the control signal generated by the DSP processor, adjust the control signal to a target control signal, and send the target control signal to the discharge circuit. The discharge circuit is used to receive the target control signal and control the transient voltage according to the target control signal. The target control signal can be used to control the operating state of the discharge circuit. For example, the control signal generated by the DSP processor can be a 3V voltage signal. After processing by the driving circuit, the 3V voltage signal is adjusted to a 15V voltage signal, and the 15V voltage signal is used as the target control signal. After receiving the target control signal, the discharge circuit starts or stops the discharge based on the target control signal, thereby controlling the transient voltage from a hardware dimension.

[0035] Furthermore, the DSP processor is also used to control the working state of the inverter according to the overvoltage flag data to control the transient voltage. Specifically, the DSP processor can know the transient voltage triggering state of the inverter according to the overvoltage flag data, and the transient voltage triggering state of the inverter is transient voltage triggered or transient voltage not triggered. In the case of a transient voltage being triggered, the transient voltage is reduced by the discharge circuit. At the same time, the inverter can be controlled to stop working, thereby realizing the software dimension and the hardware dimension to jointly adjust the transient voltage and quickly adjust the transient voltage to an ideal state; in the case of no transient voltage being triggered or the transient voltage has dropped to an ideal state, the discharge circuit is stopped to avoid additional power loss, and the inverter is controlled to start working and resume normal operation.

[0036] It should be noted that, in the embodiment of the present invention, since the transient voltage may include a positive transient voltage and a negative transient voltage, controlling the transient voltage may include lowering or raising the value of the transient voltage, which may enable the DSP processor to perform control according to actual needs. The embodiment of the present invention does not specifically limit this.

[0037] An embodiment of the present invention includes: a discharge circuit, a drive circuit, a sampling circuit, and a DSP processor; the discharge circuit is disposed at the output end of the inverter; the DSP processor is electrically connected to the discharge circuit via the drive circuit; the DSP processor is electrically connected to the output end of the inverter via the sampling circuit; the sampling circuit is configured to collect a voltage at a voltage output end of the inverter; the DSP processor is configured to read the voltage at the inverter output end, determine a target voltage component based on the voltage at the inverter output end, generate a control signal and overvoltage flag data based on the target voltage component and a preset voltage threshold, and send the control signal to the drive circuit; wherein the overvoltage flag data is used to indicate a transient voltage triggering state of the inverter; the drive circuit is configured to receive the control signal, adjust the control signal to a target control signal, and send the target control signal to the discharge circuit; the discharge circuit is configured to receive the target control signal and control the transient voltage according to the target control signal; and the DSP processor is further configured to control the operating state of the inverter according to the overvoltage flag data to control the transient voltage. The embodiment of the present invention, based on a sampling circuit and a DSP processor, can collect the voltage at the output of the inverter in real time, determine a target voltage component based on the voltage at the output of the inverter, generate a control signal based on the target voltage component, a preset voltage threshold, and overvoltage flag data, and then use a drive circuit to adjust the control signal to a target control signal. The target control signal is then sent to the discharge circuit, so that the discharge circuit controls the transient voltage from a hardware dimension according to the target control signal. The DSP processor controls the operating state of the inverter according to the overvoltage flag data, thereby controlling the transient voltage from a software dimension. The embodiment of the present invention combines software and hardware dimensions to achieve transient voltage control, thereby quickly adjusting the output voltage of the inverter to a target state within a certain time range.

[0038] In one possible implementation, the DSP processor includes: a second-order generalized integrator, a calculation module, and a screening module; the second-order generalized integrator is used to generate a first voltage signal and a second voltage signal based on the voltage at the output end of the inverter; wherein the first voltage signal and the second voltage signal are orthogonal to each other; the calculation module is used to perform a Park transform on the first voltage signal and the second voltage signal to obtain a first voltage component and a second voltage component; and the screening module is used to select the larger value of the first voltage component and the second voltage component as the target voltage component.

[0039] In this possible implementation, a second-order generalized integrator (SOGI) can generate two mutually orthogonal signals based on the voltage at the inverter output: a first voltage signal and a second voltage signal. Specifically, the second-order generalized integrator is configured to generate the first voltage signal and the second voltage signal based on the voltage at the inverter output. The first voltage signal and the second voltage signal are mutually orthogonal. The first and second voltage signals are AC signals, and after Park transformation, first and second voltage components of DC signals can be obtained.

[0040] It should be noted that, considering that the AC signal may include positive and negative values, it may not be convenient for the subsequent software-dimensional data processing process. Therefore, the first voltage signal and the second voltage signal can be converted into a first voltage component and a second voltage component through Park transformation, thereby realizing the conversion from AC to DC, so that subsequent processing can be performed based on the obtained voltage components.

[0041] In one embodiment, a screening module can be used to select the larger value of the first voltage component and the second voltage component as the target voltage component, so that subsequent data processing is performed based on the target voltage component. It should be noted that the smaller value of the first voltage component and the second voltage component can also be used as the target voltage component or used to generate the target voltage component. The method for determining the target voltage component can be determined based on actual needs.

[0042] In a possible implementation, the preset voltage threshold includes: a first threshold and a second threshold. The control signal includes: a first control signal and a second control signal. The DSP processor includes: a control module and a sending module.

[0043] The control module is used to generate the first control signal when the target voltage component is greater than the first threshold, and to modify the value of the overvoltage flag data to the first data when the target voltage component is greater than the first threshold, that is, to generate overvoltage flag data for characterizing the transient voltage triggered by the inverter.

[0044] The control module is also used to generate the second control signal when the target voltage component is less than the second threshold, and to modify the first data to second data when the target voltage component is less than the second threshold, that is, to generate overvoltage flag data for characterizing that the inverter has not triggered a transient voltage.

[0045] The sending module is used to send the first control signal or the second control signal to the driving circuit.

[0046] In this possible implementation, the preset voltage threshold includes a first threshold and a second threshold, wherein the first threshold is greater than the second threshold. The control signal is used to control the discharge circuit to different operating states, and includes a first control signal and a second control signal, wherein the first control signal is used to control the discharge circuit to start, and the second control signal is used to control the discharge circuit to stop.

[0047] It can be understood that when the target voltage component is greater than the first threshold, the control module generates the first control signal and modifies the value of the overvoltage flag data to the first data. When the target voltage component is greater than the first threshold, it indicates that the inverter has triggered a transient overvoltage of the mains, so the first control signal is generated at this time. The first control signal can be a high-level control signal, which can control the discharge circuit to start working and discharge the output port voltage of the inverter, so that the output port voltage of the inverter can drop as quickly as possible. The DSP processor modifies the value of the parameter representing the overvoltage flag data to the first data. For example, the first data can be "1", thereby indicating that the current inverter has triggered a transient overvoltage of the mains.

[0048] Furthermore, when the target voltage component is less than the second threshold, the control module generates the second control signal and modifies the first data to the second data. When the target voltage component is less than the second threshold, it indicates that the inverter has not triggered a transient overvoltage or transient voltage of the mains at this time, so the second control signal is generated at this time. The second control signal can be a low-level control signal. The low-level control signal can control the discharge circuit to stop working, that is, stop discharging the output port voltage of the inverter, thereby reducing unnecessary power loss. At this time, the first data is modified to the second data. For example, the first data can be "1" and the second data can be "0". The "1" is adjusted to "0", thereby indicating that the inverter has not triggered a transient overvoltage or transient voltage of the mains at this time.

[0049] The control module can generate a first control signal or a second control signal after data processing, and the sending module can be used to send the first control signal or the second control signal to the drive circuit for further data processing by the drive circuit. Upon receiving the first control signal and before receiving the second control signal, the drive circuit controls the bleeder circuit to be in a bleeder state, thereby causing the voltage at the output port of the inverter to drop as quickly as possible until the target voltage component is less than a second threshold. Then, the control module generates a second control signal, and the drive circuit controls the bleeder circuit to stop operating according to the second control signal.

[0050] In one possible implementation, the DSP processor further includes an adjustment module configured to adjust the inverter to a non-operating state when the value of the overvoltage flag data is the first data, and to adjust the inverter to an operating state when the value of the overvoltage flag data is the second data.

[0051] In this possible implementation, the adjustment module is used to adjust the inverter to a non-operating state when the value of the overvoltage flag data is the first data. Specifically, when the value of the overvoltage flag data is the first data, it indicates that there is a transient voltage at the output end of the inverter. Therefore, the adjustment module is used to adjust the inverter to a non-operating state, thereby cooperating with the discharge circuit to adjust the transient voltage to an ideal state more quickly. It should be noted that if the output of the inverter is not turned off, then when there is an overvoltage, it is equivalent to the inverter maintaining discharge, while the discharge circuit is discharging the voltage. The two are operating in opposite directions at the same time, which is not conducive to quickly adjusting the transient voltage. Therefore, the discharge of the inverter is stopped, that is, the inverter is adjusted to a non-operating state, so that the voltage can be quickly discharged in cooperation with the discharge circuit.

[0052] In addition, the adjustment module is further configured to adjust the inverter to an operating state when the value of the overvoltage flag data is the second data. Specifically, when the value of the overvoltage flag data is the second data, it indicates that there is no transient voltage at the output end of the inverter. Therefore, the adjustment module is configured to adjust the inverter to an operating state and restore normal operation.

[0053] In one possible implementation, the drive circuit includes: a first filter module, an isolation chip, a second filter module, and a drive resistor module. A first end of the first filter module is electrically connected to the DSP processor, a second end of the first filter module is electrically connected to a first end of the isolation chip, a second end of the isolation chip is electrically connected to an auxiliary power supply via the second filter module, and a second end of the isolation chip is electrically connected to the bleeder circuit via the drive resistor module.

[0054] In this possible implementation, the first end of the first filter module is electrically connected to the DSP processor, and the second end of the first filter module is electrically connected to the first end of the isolation chip, so that the first filter module can filter the signal output by the DSP processor and send it to the isolation chip. The second end of the isolation chip is electrically connected to the auxiliary power supply through the second filter module, so as to receive the power supply signal filtered by the second filter module. The second end of the isolation chip is electrically connected to the discharge circuit through the drive resistor module, so as to send the control signal of the DSP processor to the discharge circuit. It should be noted that the isolation chip provides electrical isolation between circuits to prevent mutual interference and transmission of current, voltage or signals, thereby protecting the circuit and transmitting signals.

[0055] In one possible embodiment, the first filter module includes a first capacitor and a first resistor; wherein the first capacitor and the first resistor are arranged in parallel. The second filter module includes a second capacitor. The second end of the isolation chip includes a first interface, a second interface, and a third interface, and the isolation chip is electrically connected to the second capacitor through the first interface and the third interface. The driving resistance module includes a second resistor and a third resistor, and the discharge circuit includes a switch tube and a fourth resistor, and the switch tube is connected in series with the fourth resistor. wherein the first end of the second resistor is electrically connected to the second interface, the second end of the second resistor is electrically connected to the first end of the switch tube and the first end of the third resistor, and the second end of the third resistor is electrically connected to the third interface, the second end of the switch tube, and the first end of the fourth resistor. the discharge circuit is electrically connected to the output end of the inverter through the second end of the fourth resistor and the third end of the switch tube.

[0056] More specifically, referring to the circuit structure diagram of the transient voltage control device for an inverter according to an embodiment of the present invention shown in FIG5 , the first filtering module includes a first capacitor C1 and a first resistor R1; the first capacitor and the first resistor are arranged in parallel. The second filtering module includes a second capacitor C2. The second end of the isolation chip U1 includes a first interface VCC, a second interface VOUT, and a third interface VEE. The isolation chip is electrically connected to the second capacitor C2 via the first interface VCC and the third interface VEE. The driving resistor module includes a second resistor R2 and a third resistor R3. The bleeder circuit includes a switch Q1 and a fourth resistor R4. The first end of the second resistor R2 is electrically connected to the second interface VOUT, the second end of the second resistor R2 is electrically connected to the first end of the switch Q1 and the first end of the third resistor R3, and the second end of the third resistor is electrically connected to the third interface VEE, the second end of the switch Q1, and the first end of the fourth resistor R4. The bleeder circuit is electrically connected to the output of the inverter via the second end of the fourth resistor R4 and the third end of the switch Q1.

[0057] The DSP processor is used to control the switch tube Q1 to turn on through the drive circuit to discharge the voltage at the output end of the inverter when the target voltage component is greater than the first threshold, and to control the switch tube Q1 to turn off through the drive circuit to stop discharging the voltage at the output end of the inverter when the target voltage component is less than the first threshold.

[0058] In this possible implementation, the first end of isolation chip U1 includes three interfaces: ANODE (anode), NC (No Connection), and CATHODE (cathode). The second end includes three interfaces: VCC (positive power pin), VOUT (voltage output), and VEE (negative power pin). The drive circuit includes drive resistors R2 and R3. Drive resistors limit current, protect components, control component status, and provide matching circuits to ensure normal circuit operation and safe component operation.

[0059] Based on the circuit structure shown in FIG5 , the following describes the steps for implementing transient voltage control using the device using a specific embodiment:

[0060] Step S001: the inverter samples the mains voltage in each control cycle through a sampling circuit.

[0061] Step S002: The DSP processor reads the mains voltage sampling value and generates two mutually orthogonal signals U through the second-order generalized integrator SOGI. α and U β .

[0062] Step S003: In the current control cycle, the DSP processor changes the formula by Park The two voltage components U in the rotating dq coordinate system (a two-dimensional coordinate system) are calculated d and U q . Among them U d is the first voltage signal, U q is the first voltage signal.

[0063] Step S004: Set the maximum overvoltage value MAX_OVP according to different regulations. d Component judgment threshold U d-max .

[0064] Step S005: In the current control cycle, use the mains voltage component U d and U d-max For comparison, when U d Greater than the threshold U d-maxWhen the inverter triggers a transient overvoltage on the mains, a high-level control signal is required to the discharge circuit and the transient overvoltage flag, OvpFlag = 1, is set. It should be noted that after the software identifies the overvoltage, the DSP output pin is set to a high level. This high level is a 3V voltage signal, which is the DRIVE signal in Figure 5. After the 3V voltage signal passes through the isolation chip U1, the isolation chip outputs a 15V voltage signal. This 15V voltage signal turns on the switch Q1. Setting the flag can be achieved by assigning a variable in the code to "1". This variable is defined as OvpFlag. The specific assignment operation can be achieved using the following formula: OvpFlag = 1.

[0065] Step S006: After the high-level control signal passes through the driving circuit, the discharge circuit is controlled to start working, so that the output port voltage of the inverter can drop to 0 as quickly as possible.

[0066] Step S007: In the current control cycle, when the DSP processor detects that the transient voltage overvoltage flag is set, the DC / AC inverter drive signal is turned off.

[0067] Step S008: In the next control cycle, the DSP processor uses the mains voltage component U d and U d-min When the transient voltage overvoltage flag OvpFlag is 1 and U d Less than U d-min When the transient voltage is under control, the DSP processor sends a low-level control signal to the discharge circuit, which turns off the switch Q1 and clears the transient voltage overvoltage flag, setting OvpFlag to 0.

[0068] Step S009: In the next control cycle, the low-level control signal from the DSP controller passes through the driver circuit, causing the discharge circuit to stop operating. Simultaneously, the DC / AC inverter drive signal is turned on. It should be noted that the inverter drive signal is the drive signal for the switching transistors in the inverter circuit. The drive signal controls the operation of the inverter circuit. When the drive signal is present, the inverter circuit is operating, converting DC voltage into AC voltage.

[0069] When the above steps are implemented, the working process of the discharge circuit includes:

[0070] 1. After the photovoltaic panel PV is turned on, the DSP processor operates normally and one of the windings of the auxiliary power supply outputs 15V as the driving power supply. At this time, the switch tube Q1 is in the off state.

[0071] 2. After the inverter is connected to the grid, it enters normal working state and the switch tube Q1 is disconnected.

[0072] 3. When transient voltage occurs, the DSP processor detects that the voltage at the inverter output is greater than the software judgment value, and the DSP processor sends a drive signal to Q1 through the isolated drive signal. At this time, Q1 is closed and the transient voltage is discharged through resistor R4.

[0073] 4. When the DSP processor detects that the transient voltage is less than the judgment value, the switch tube Q1 is disconnected.

[0074] In the above steps, the auxiliary power supply is a flyback circuit. The flyback circuit input is the PV voltage (PV+ and PV-), the output is 15V, and 15V_GND is the output ground. The auxiliary power supply is mainly used to drive the switching transistor of the discharge circuit.

[0075] In the driver circuit described above, the DSP processor's GPIO port serves as the output port (DRIVE in the diagram). U1 is the isolation chip, while C1 and R1 form a filter circuit to filter the isolation chip's input. The isolation chip's ANODE is the signal input pin, CATHODE is the chip's ground connection, VCC is the 15V auxiliary power supply, and VOUT is the isolation chip's output. C2 provides power supply filtering for the isolation chip's input. R2 and R3 are the drive resistors for the isolation chip's output. C1, R1, U1, C2, R2, and R3 form the driver circuit, converting the 3V output of the DSP chip into a 15V signal.

[0076] In the above steps, the discharge circuit is composed of the switch Q1 and the fourth resistor R4, wherein Q1 is an IGBT or a MOS tube and includes parasitic parameters such as a capacitor and a diode.

[0077] In a possible implementation, the auxiliary power supply further includes a photovoltaic panel, and the photovoltaic panel is electrically connected to the second filter module via a flyback circuit.

[0078] A photovoltaic panel, also known as a solar panel, is a device that converts solar energy into electrical energy. It consists of multiple photovoltaic cells, each made of a semiconductor material, usually silicon. When sunlight shines on a photovoltaic panel, the photons excite the electrons in the photovoltaic cell, causing them to jump from a low energy level to a high energy level, thereby generating an electric current. This current can be used to supply power or stored for later use. Photovoltaic panels are widely used in solar power generation systems and can be used in homes, businesses, and industries. They can be installed on rooftops, on the ground, or in other suitable locations to maximize the absorption of solar energy. The power of photovoltaic panels is usually marked in watts (W), and panels of different power can be selected according to needs.

[0079] The photovoltaic panel is electrically connected to the second filter module via a flyback circuit. A flyback circuit is a switching power supply topology used to convert an input voltage into a desired output voltage. It primarily consists of a switching tube, a transformer, an output rectifier circuit, and a feedback control circuit. The flyback circuit has a relatively simple topology, requires fewer components, and is relatively low in cost. Furthermore, the flyback circuit has high energy conversion efficiency and can achieve a high power density. The output voltage can be adjusted by adjusting the on-time of the switching tube.

[0080] See Figure 4 for a schematic diagram of an implementation of a transient voltage control device for an inverter according to an embodiment of the present invention. In the figure, GRID represents the connection point between the inverter and the power grid. DC / AC represents the inverter. When using this device, a bleeder circuit is placed at the output of the inverter. A circuit is used to collect the voltage at the inverter output in real time from the power grid or electric power system. A DSP processor processes and calculates this voltage to generate a control signal, which is then transmitted to the bleeder circuit via a drive circuit. The bleeder circuit then controls transient voltage by switching its operation on and off.

[0081] The present invention provides a device and method for controlling transient voltage in an inverter. This device combines software and hardware to control the inverter's transient voltage. The software detects voltage components in real time and sends control signals to a bleeder circuit, which controls the transient voltage through hardware. The bleeder circuit's operating threshold can be set to different thresholds based on regulatory requirements, better meeting practical needs. Furthermore, the device's implementation method is flexible and simplifies the hardware circuit structure compared to existing solutions.

[0082] Based on the above-mentioned transient voltage control device for the inverter provided by an embodiment of the present invention, an embodiment of the present invention further provides a transient voltage control method for the inverter, which is applied to a DSP processor. The method includes: collecting the voltage at the output end of the inverter through a sampling circuit; determining a target voltage component based on the voltage at the output end of the inverter, and generating a control signal and the overvoltage flag data according to the target voltage component and a preset voltage threshold; wherein the overvoltage flag data is used to characterize the transient voltage triggering state of the inverter; sending the control signal to a drive circuit so that the drive circuit adjusts the control signal to a target control signal, sending the target control signal to a discharge circuit, and causing the discharge circuit to receive the target control signal and control the transient voltage according to the target control signal; and controlling the working state of the inverter according to the overvoltage flag data to control the transient voltage.

[0083] Embodiments of the present invention can acquire the voltage at the inverter output in real time, determine a target voltage component based on the voltage at the inverter output, generate a control signal based on the target voltage component, a preset voltage threshold, and overvoltage flag data, and then use a drive circuit to adjust the control signal to a target control signal. The target control signal is then sent to a discharge circuit, causing the discharge circuit to control the transient voltage from a hardware dimension according to the target control signal. A DSP processor is used to control the operating state of the inverter based on the overvoltage flag data, thereby controlling the transient voltage from a software dimension. Embodiments of the present invention achieve transient voltage control based on a combination of software and hardware dimensions, thereby quickly adjusting the inverter output voltage to a target state within a certain time range.

[0084] In one possible embodiment, determining a target voltage component based on the voltage at the inverter output end includes: generating a first voltage signal and a second voltage signal based on the voltage at the inverter output end; wherein the first voltage signal and the second voltage signal are orthogonal to each other; performing a Park transformation on the first voltage signal and the second voltage signal to obtain a first voltage component and a second voltage component; and taking the larger value of the first voltage component and the second voltage component as the target voltage component.

[0085] In one possible embodiment, the preset voltage threshold includes: a first threshold and a second threshold; the control signal includes: a first control signal and a second control signal; generating a control signal and the overvoltage flag data according to the target voltage component and the preset voltage threshold, and sending the control signal to the drive circuit, including: when the target voltage component is greater than the first threshold, generating the first control signal and modifying the value of the overvoltage flag data to the first data, and when the target voltage component is less than the second threshold, generating the second control signal and modifying the value of the overvoltage flag data to the second data; sending the first control signal or the second control signal to the drive circuit.

[0086] In one possible implementation, controlling the working state of the inverter according to the overvoltage flag data includes: when the value of the overvoltage flag data is the first data, adjusting the inverter to a non-working state, and when the value of the overvoltage flag data is the second data, adjusting the inverter to a working state.

[0087] In one possible implementation, the drive circuit includes: a first filter module, an isolation chip, a second filter module, and a drive resistor module; the first end of the first filter module is electrically connected to the DSP processor, the second end of the first filter module is electrically connected to the first end of the isolation chip, the second end of the isolation chip is electrically connected to the auxiliary power supply through the second filter module, and the second end of the isolation chip is electrically connected to the discharge circuit through the drive resistor module.

[0088] In one possible implementation, the discharge circuit includes a switch tube and a fourth resistor; the first filtering module includes a first capacitor and a first resistor; wherein the first capacitor and the first resistor are arranged in parallel; the second filtering module includes a second capacitor; the second end of the isolation chip includes a first interface, a second interface, and a third interface, and the isolation chip is electrically connected to the second capacitor through the first interface and the third interface; the driving resistance module includes a second resistor and a third resistor, the first end of the second resistor is electrically connected to the second interface, the second end of the second resistor is electrically connected to the first end of the switch tube and the first end of the third resistor, and the second end of the third resistor is electrically connected to the third interface, the second end of the switch tube, and the first end of the fourth resistor; the discharge circuit is electrically connected to the output end of the inverter through the second end of the fourth resistor and the third end of the switch tube.

[0089] In a possible implementation, the auxiliary power source is a photovoltaic panel, and the photovoltaic panel is electrically connected to the second filter module via a flyback circuit.

[0090] An embodiment of the present invention further provides an electronic device comprising: at least one processor; and a memory communicatively connected to the at least one processor. The memory stores a computer program executable by the at least one processor, wherein the computer program, when executed by the at least one processor, causes the electronic device to perform the method of the embodiment of the present invention.

[0091] An embodiment of the present invention further provides a non-transitory machine-readable medium storing a computer program, wherein the computer program, when executed by a processor of a computer, is used to cause the computer to perform the method of the embodiment of the present invention.

[0092] With reference to Figure 3, the structural block diagram of the electronic device that can be used as the server or client of an embodiment of the present invention will now be described, which is an example of a hardware device that can be applied to various aspects of the present invention. The electronic device is intended to represent various forms of digital electronic computer equipment, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0093] As shown in Figure 3, the electronic device includes a computing unit 301, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 302 or a computer program loaded from a storage unit 308 into a random access memory (RAM) 303. In RAM 303, various programs and data required for the operation of the electronic device can also be stored. The computing unit 301, ROM 302, and RAM 303 are connected to each other via a bus 304. An input / output (I / O) interface 305 is also connected to the bus 304.

[0094] Multiple components within the electronic device are connected to the I / O interface 305, including an input unit 306, an output unit 307, a storage unit 308, and a communication unit 309. The input unit 306 can be any type of device capable of inputting information into the electronic device. The input unit 306 can receive input numeric or character information and generate key signal inputs related to user settings and / or function control of the electronic device. The output unit 307 can be any type of device capable of presenting information and may include, but is not limited to, a display, a speaker, a video / audio output terminal, a vibrator, and / or a printer. The storage unit 308 may include, but is not limited to, a magnetic disk or an optical disk. The communication unit 309 allows the electronic device to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks and may include, but is not limited to, a modem, a network card, an infrared communication device, a wireless communication transceiver, and / or a chipset, such as a Bluetooth device, a WiFi device, a WiMax device, a cellular communication device, and / or the like.

[0095] The computing unit 301 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 301 include, but are not limited to, a CPU, a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units that run machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 301 performs the various methods and processes described above. For example, in some embodiments, the method embodiments of the present invention may be implemented as a computer program, which is tangibly contained in a machine-readable medium, such as a storage unit 308. In some embodiments, part or all of the computer program may be loaded and / or installed on an electronic device via ROM 302 and / or communication unit 309. In some embodiments, the computing unit 301 may be configured to perform the above-described method in any other appropriate manner (e.g., by means of firmware).

[0096] The computer programs for implementing the methods of the embodiments of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer programs are executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The computer programs may be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0097] In the context of an embodiment of the present invention, a machine-readable medium can be a tangible medium that can contain or store a program for use by an instruction execution system, device or equipment or used in combination with an instruction execution system, device or equipment. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable signal medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared or semiconductor system, device or equipment, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium can include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0098] It should be noted that the term "including" and its variations used in the embodiments of the present invention are open-ended, i.e., "including but not limited to." The term "based on" means "based at least in part on." The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; and the term "some embodiments" means "at least some embodiments." The modifications of "one" and "a plurality of" mentioned in the embodiments of the present invention are illustrative and non-restrictive. Those skilled in the art should understand that, unless the context clearly indicates otherwise, they should be understood as "one or more."

[0099] The user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in the embodiments of the present invention are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with the relevant laws, regulations and standards of relevant countries and regions, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0100] The various steps described in the method implementation scheme provided in the embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method implementation scheme may include additional steps and / or omit the steps shown. The scope of protection of the present invention is not limited in this respect.

[0101] The term "embodiment" in this specification refers to specific features, structures, or characteristics described in conjunction with the embodiment that can be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. The various embodiments in this specification are described in a related manner, and the same or similar parts between the various embodiments are referenced to each other. In particular, for the embodiments of the device, equipment, and system, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts are referred to the partial description of the method embodiment.

[0102] The above-described embodiments merely illustrate several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of the present invention. Therefore, the scope of the present invention shall be determined by the appended claims.

Claims

1. A transient voltage control device for an inverter, characterized in that: include: Discharge circuit, drive circuit, sampling circuit and DSP processor; The discharge circuit is arranged at the output end of the inverter; The DSP processor is electrically connected to the discharge circuit through the drive circuit; the DSP processor is electrically connected to the output end of the inverter through the sampling circuit; The sampling circuit is used to collect the voltage at the output end of the inverter; The DSP processor is used to obtain the voltage at the output end of the inverter and determine the target voltage component based on the voltage at the output end of the inverter; The DSP processor is also used to control the discharge circuit to discharge the voltage at the output end of the inverter through the drive circuit when the target voltage component is greater than a first threshold value, and to generate overvoltage flag data for characterizing the inverter triggering transient voltage, and in response to the overvoltage flag data for characterizing the inverter triggering transient voltage, control the inverter to be in a non-working state.

2. The device according to claim 1, characterized in that The DSP processor is also used to control the discharge circuit to stop discharging the voltage at the output end of the inverter through the drive circuit when the target voltage component is less than a second threshold value, and to generate overvoltage mark data for characterizing that the inverter does not trigger a transient voltage, and in response to the overvoltage mark data for characterizing that the inverter does not trigger a transient voltage, control the inverter to be in a working state; wherein the second threshold value is less than the first threshold value.

3. The device according to claim 1, characterized in that The DSP processor is used to generate a first voltage signal and a second voltage signal based on the voltage at the output end of the inverter; wherein the first voltage signal and the second voltage signal are orthogonal to each other; And, it is used to perform Park transformation on the first voltage signal and the second voltage signal to obtain a first voltage component and a second voltage component, and use the larger value of the first voltage component and the second voltage component as the target voltage component.

4. The device according to claim 3, characterized in that The DSP processor generates a first voltage signal and a second voltage signal through a second-order generalized integrator based on the voltage at the output terminal of the inverter.

5. The device according to claim 2, characterized in that The DSP processor is used for generating a first control signal and sending it to the driving circuit when the target voltage component is greater than the first threshold value, and modifying the value of the overvoltage flag data to the first data; When the target voltage component is less than the second threshold, a second control signal is generated and sent to the driving circuit, and the first data is modified into second data.

6. The device according to claim 5, characterized in that The DSP processor is further used for adjusting the inverter to a non-working state when the value of the overvoltage flag data is the first data, and for adjusting the inverter to a working state when the value of the overvoltage flag data is the second data.

7. The device according to claim 5, characterized in that The driving circuit is used to receive the first control signal or the second control signal, adjust the first control signal or the second control signal to a corresponding target control signal, and send the target control signal to the discharge circuit; the target control signal is used to control the working state of the discharge circuit.

8. The device according to claim 1, characterized in that The driving circuit includes: a first filtering module, an isolation chip, a second filtering module and a driving resistance module; the first end of the first filtering module is electrically connected to the DSP processor, the second end of the first filtering module is electrically connected to the first end of the isolation chip, the second end of the isolation chip is electrically connected to the auxiliary power supply through the second filtering module, and the second end of the isolation chip is electrically connected to the discharge circuit through the driving resistance module.

9. The device according to claim 8, characterized in that The discharge circuit includes a switch tube and a fourth resistor connected in series; the DSP processor is used to control the switch tube to be turned on through the drive circuit to discharge the voltage at the output end of the inverter when the target voltage component is greater than the first threshold, and to control the switch tube to be turned off through the drive circuit to stop discharging the voltage at the output end of the inverter when the target voltage component is less than the first threshold.

10. The device according to claim 9, characterized in that The first filtering module includes a first capacitor and a first resistor; wherein the first capacitor and the first resistor are arranged in parallel; The second filtering module includes a second capacitor; The second end of the isolation chip comprises a first interface, a second interface and a third interface, and the isolation chip is electrically connected to the second capacitor through the first interface and the third interface; The driving resistor module includes a second resistor and a third resistor, wherein a first end of the second resistor is electrically connected to the second interface, a second end of the second resistor is electrically connected to a first end of the switch tube and a first end of the third resistor respectively, and a second end of the third resistor is electrically connected to the third interface, a second end of the switch tube, and a first end of the fourth resistor respectively; The second end of the fourth resistor and the third end of the switch tube are electrically connected to the output end of the inverter.

11. The device according to claim 8, characterized in that The auxiliary power source is a photovoltaic panel, and the photovoltaic panel is electrically connected to the second filter module through a flyback circuit.

12. A method for controlling transient voltage of an inverter, characterized in that: Applied to a DSP processor, the method comprises: The voltage at the output end of the inverter is collected through a sampling circuit; determining a target voltage component based on a voltage at an output terminal of the inverter; When the target voltage component is greater than a first threshold, the discharge circuit is controlled by the driving circuit to discharge the voltage at the output end of the inverter, and overvoltage mark data for characterizing the inverter triggering transient voltage is generated, and in response to the overvoltage mark data for characterizing the inverter triggering transient voltage, the inverter is controlled to be in a non-working state; Alternatively, when the target voltage component is less than a second threshold value, the discharge circuit is controlled by the drive circuit to stop discharging the voltage at the output end of the inverter, and overvoltage mark data for characterizing that the inverter does not trigger a transient voltage is generated, and in response to the overvoltage mark data for characterizing that the inverter does not trigger a transient voltage, the inverter is controlled to be in a working state; wherein the second threshold value is less than the first threshold value.

13. An electronic device, characterized in that: include: A processor, and a memory storing a program, wherein the program includes instructions that, when executed by the processor, cause the processor to perform the method according to claim 12.

14. A non-transitory machine-readable medium storing computer instructions, characterized in that: The computer instructions are used to cause the computer to execute the method according to claim 12.

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