A modulated voltage signal timing transmission system and method

Abstract

This invention relates to a system and method for timing the transmission of modulated voltage signals, belonging to the field of flexible DC and flexible low-frequency power transmission technology. The system for timing the transmission of modulated voltage signals of this invention involves an electrical quantity acquisition module acquiring the electrical quantity signals required by the control algorithm, and then actively sending them to the control algorithm module. Simultaneously, interrupt and start signals are sent to the control algorithm module and the modulation signal transmission module, respectively. Finally, the modulation signal transmission module periodically sends the modulated voltage signal calculated by the control algorithm module to the valve control device. By optimizing the data transmission algorithm, the system ensures the synchronization of different types of electrical quantity signal transmission, improves data transmission efficiency, reduces data transmission link delay, effectively reduces the link delay of the converter control system, suppresses AC harmonic oscillation problems, and ensures the normal and stable operation of the AC power grid system and the transmission system, thereby improving the stability and reliability of the transmission system.

Description

Technical Field

[0001] This invention relates to a system and method for timing the transmission of modulated voltage signals, belonging to the field of flexible DC and flexible low-frequency power transmission technology. Background Technology

[0002] With the increasing sophistication of manufacturing processes for fully controlled power electronic devices such as IGBTs, flexible DC transmission and flexible low-frequency transmission technologies have moved from theory to engineering applications. In particular, the development of flexible DC transmission technology has been particularly prominent. With the rapid development of offshore wind power in deep and remote waters, flexible low-frequency transmission technology will also usher in new development opportunities.

[0003] Whether it's flexible DC transmission technology or flexible low-frequency transmission technology, the core equipment is control and protection equipment, and the requirements for link delay in converter control systems are becoming increasingly stringent. In traditional converter control systems, analog and digital electrical signals are acquired by different acquisition modules or plug-ins, and the two types of signals cannot be synchronized when sent to the control algorithm module. Furthermore, the digital electrical signals are sent to the digital electrical signal acquisition module or plug-in via the current transformer photoelectric conversion module and optical merging unit, which not only increases the link delay of the converter control system but also increases the risk of failure.

[0004] Traditional analog and digital electrical signal acquisition modules store data. When the control algorithm module's processor receives an interrupt and starts, it retrieves the data from the acquisition module, stores it in memory, and then processes it to calculate the modulated voltage signal, which is then sent to the valve controller via the modulation signal transmission module. Therefore, this traditional data transmission mechanism also increases the link delay in the converter control system. Furthermore, due to the fluctuating nature of the control algorithm module's processor calculations, the modulated voltage signal sent to the valve controller exhibits significant fluctuations, making it impossible for the valve controller to achieve tracking synchronization.

[0005] In summary, the current methods of acquiring electrical quantities, transmitting data, and transmitting modulated voltage signals in converter control systems all cause link delays in the converter control system, affecting the stability and reliability of the power transmission system. Therefore, there is an urgent need to develop a modulated voltage signal timing transmission system that can effectively reduce the link delay of the converter control system and ensure the stability and reliability of the power transmission system. Summary of the Invention

[0006] The purpose of this invention is to provide a modulated voltage signal timing transmission system that can effectively reduce the link delay of the converter control system and ensure the stability and reliability of the power transmission system.

[0007] Another object of the present invention is to provide a method for timing transmission of modulated voltage signals.

[0008] To achieve the above objectives, the technical solution adopted by the modulation voltage signal timing transmission system of the present invention is as follows:

[0009] A system for timing the transmission of modulated voltage signals includes an electrical quantity acquisition module, a control algorithm module, and a modulated signal transmission module; the control algorithm module includes a processing unit and a storage unit.

[0010] The electrical quantity acquisition module is used to acquire the electrical quantity signals required by the control algorithm in each control cycle, and then actively transmit the electrical quantity signals to the storage unit of the control algorithm module, while transmitting the start signal to the modulation signal transmission module; the electrical quantity signals include MSI interrupt signals;

[0011] The processing unit is used to extract the electrical quantity signal from the storage unit when the control algorithm module receives the MSI interrupt signal in each control cycle, and then calculate and generate the modulation voltage signal required by the converter and store it in the storage unit.

[0012] The modulation signal transmitting module extracts the modulation voltage signal from the storage unit and transmits it to the valve control device when a predetermined time is reached after receiving the start signal in each control cycle.

[0013] The predetermined time is equal to the sum of the maximum value of the transmission and storage time in all control cycles and the reserved time. The transmission and storage time is the time from when the electrical quantity acquisition module starts sending electrical quantity signals to the control algorithm module to when the modulated voltage signal is stored in the storage unit.

[0014] The modulation voltage signal timing transmission system of the present invention comprises an electrical quantity acquisition module, a control algorithm module, and a modulation signal transmission module. The electrical quantity acquisition module acquires the electrical quantity signals required by the control algorithm and actively transmits them to the control algorithm module. Simultaneously, it sends interrupt and start signals to the control algorithm module and the modulation signal transmission module, respectively. Finally, the modulation signal transmission module periodically transmits the modulation voltage signal calculated by the control algorithm module to the valve control device. By optimizing the data transmission algorithm, the system ensures the synchronization of different types of electrical quantity signal transmission, improves data transmission efficiency, reduces data transmission link delay, effectively reduces the link delay of the converter control system, suppresses AC harmonic oscillation problems, and ensures the normal and stable operation of the AC power grid system and transmission system, thereby improving the stability and reliability of the transmission system.

[0015] Preferably, the electrical quantity acquisition module includes a digital electrical quantity signal acquisition unit, an analog electrical quantity signal acquisition unit, and an electrical quantity signal processing unit. The digital electrical quantity signal acquisition unit is used to acquire digital electrical quantity signals, the analog electrical quantity signal acquisition unit is used to acquire analog electrical quantity signals, and the electrical quantity signal processing unit is used to perform A / D conversion on the analog electrical quantity signals and reassemble the converted digital signals and the acquired digital electrical quantity signals into electrical quantity signals required by the control algorithm according to a fixed arrangement order.

[0016] Preferably, the electrical quantity acquisition module sends the electrical quantity signals required by the control algorithm to the control algorithm module via the PCIe bus.

[0017] Preferably, the electrical quantity acquisition module transmits the start signal to the modulation signal transmission module via a hardware interrupt line.

[0018] The technical solution adopted in the modulation voltage signal timing transmission method of the present invention is as follows:

[0019] A method for timing the transmission of a modulated voltage signal, employing the modulated voltage signal timing transmission system described above, includes the following steps:

[0020] (1) The electrical quantity acquisition module acquires the electrical quantity signals required by the control algorithm in each control cycle, and then actively transmits the electrical quantity signals to the storage unit of the control algorithm module, while transmitting the start signal to the modulation signal transmission module; the electrical quantity signals include the MSI interrupt signal;

[0021] (2) When the control algorithm module receives the MSI interrupt signal in each control cycle, the processing unit extracts the electrical quantity signal from the storage unit, then calculates and generates the modulation voltage signal required by the converter and stores it in the storage unit.

[0022] (3) When the modulation signal transmission module receives the start signal in each control cycle and reaches a predetermined time, it extracts the modulation voltage signal from the storage unit and transmits it to the valve control device; the predetermined time is equal to the sum of the maximum value of the transmission storage time in all control cycles and the reserved time, and the transmission storage time is the time from when the electrical quantity acquisition module starts to send the electrical quantity signal to the control algorithm module to when the modulation voltage signal is stored in the storage unit.

[0023] The modulation voltage signal timing transmission method of the present invention adopts the modulation voltage signal timing transmission system described above. By optimizing the data transmission algorithm, it ensures the synchronization of transmission of different types of electrical quantity signals, improves data transmission efficiency, reduces data transmission link delay, effectively reduces the link delay of the converter control system, suppresses AC harmonic oscillation problems, and ensures the normal and stable operation of AC power grid system and power transmission system, thereby improving the stability and reliability of power transmission system.

[0024] Preferably, the electrical quantity signal required by the control algorithm is obtained by a method including the following steps: first, acquiring digital electrical quantity signals and analog electrical quantity signals; then, performing A / D conversion on the analog electrical quantity signals; and finally, recombining the converted digital signals with the acquired digital electrical quantity signals in a fixed arrangement order to form the electrical quantity signal required by the control algorithm.

[0025] Preferably, in the method for timing the transmission of modulated voltage signals, the electrical quantity acquisition module sends the electrical quantity signals required by the control algorithm to the control algorithm module via the PCIe bus.

[0026] Preferably, in the method for timing the transmission of the modulated voltage signal, the electrical quantity acquisition module transmits the start signal to the modulation signal transmission module through a hardware interrupt line. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the working process of the modulation voltage signal timing transmission system in Example 1;

[0028] Figure 2 This is a schematic diagram illustrating the calculation of the timing for transmitting the modulation signal in Example 1. Detailed Implementation

[0029] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0030] I. Specific embodiments of the modulation voltage signal timing transmission system of the present invention are as follows:

[0031] Example 1

[0032] The modulation voltage signal timing transmission system of this embodiment includes an electrical quantity acquisition module, a control algorithm module, and a modulation signal transmission module; the control algorithm module includes a processing unit and a storage unit.

[0033] The electrical quantity acquisition module is used to acquire the electrical quantity signals required by the control algorithm in each control cycle, and then actively transmit the electrical quantity signals to the storage unit of the control algorithm module, while simultaneously transmitting the start signal to the modulation signal transmission module; the electrical quantity signals include MSI interrupt signals; the electrical quantity acquisition module includes a digital electrical quantity signal acquisition unit, an analog electrical quantity signal acquisition unit, and an electrical quantity signal processing unit. The digital electrical quantity signal acquisition unit is used to acquire digital electrical quantity signals, the analog electrical quantity signal acquisition unit is used to acquire analog electrical quantity signals, and the electrical quantity signal processing unit is used to perform A / D conversion on the analog electrical quantity signals, and then reassemble the converted digital signals and the acquired digital electrical quantity signals into the electrical quantity signals required by the control algorithm according to a fixed arrangement order;

[0034] The processing unit is used to extract electrical quantity signals from the storage unit when the control algorithm module receives an MSI interrupt signal in each control cycle, then calculate and generate the modulation voltage signal required by the converter and store it in the storage unit;

[0035] In each control cycle, when the start signal is received and a predetermined time is reached, the modulation signal transmission module extracts the modulation voltage signal from the storage unit and transmits it to the valve control device.

[0036] The predetermined time is equal to the sum of the maximum value of the transmission and storage time in all control cycles and the reserved time. The transmission and storage time is the time from when the electrical quantity acquisition module starts sending electrical quantity signals to the control algorithm module to when the modulated voltage signal is stored in the storage unit.

[0037] The electrical quantity acquisition module consists of a standalone plug-in, but can also be integrated with the control algorithm module. Digital electrical quantity signals are directly connected to the digital electrical quantity signal acquisition unit via polarization-maintaining fiber from the modulator of the all-optical transformer, and are received by the FPGA of the electrical quantity acquisition module. Analog electrical quantity signals are acquired and then converted to digital signals by the FPGA of the electrical quantity acquisition module, reconstructing them with the acquired digital electrical quantity signals to form a new digital signal, which is the electrical quantity signal required by the control algorithm. The FPGA of the electrical quantity acquisition module sends the reconstructed digital signal to the control algorithm module via the PCIe bus. The FPGA of the electrical quantity acquisition module also transmits a start signal to the modulation signal transmission module via a hardware interrupt line.

[0038] The modulation signal transmission module is implemented by FPGA and integrated with the control algorithm module on a single plug-in. The modulation signal transmission module retrieves the modulation voltage signal required by the converter from the storage unit via the PCIe bus and sends it to the valve control device at regular intervals.

[0039] The working principle and process of the modulation voltage signal timing transmission system in this embodiment will be described in detail below. Taking one control cycle as an example, the working process is as follows: Figure 1As shown, it includes the following steps:

[0040] (1) The electrical quantity acquisition module starts at time T0 to acquire digital electrical quantity signals and analog electrical quantity signals at a sampling rate of 100kHz. The acquired analog electrical quantity signals are converted by A / D through the FPGA in the electrical quantity acquisition module. Then the FPGA reassembles the converted digital signal and the acquired digital electrical quantity signals into a new digital signal in a fixed arrangement order.

[0041] (2) The electrical quantity acquisition module transmits the start signal of the new digital quantity signal obtained from the first acquisition, conversion and reconstruction to the modulation signal transmission module through the hardware interrupt line at time T1. The modulation signal transmission module receives the start signal at time T2, triggers the interrupt, and starts timing.

[0042] (3) At time T1, the FPGA in the electrical quantity acquisition module actively sends the reconstructed new digital signal to the memory in the control algorithm module through the 2.5Gbps PCIe bus. The signal transmitted by the PCIe bus includes the MSI interrupt signal. The control algorithm module receives the MSI interrupt signal at time T2. The PCIe transmission time from T1 to T2 is relatively stable and is directly related to the number of digital signals transmitted by the electrical quantity acquisition module. It is often less than 3μs. Since the same signal is sent to the modulation signal transmission module and the control algorithm module at time T1, the circuit settings can ensure that the modulation signal transmission module and the control algorithm module receive the signal at the same time (time T2).

[0043] (4) After receiving the MSI interrupt signal at time T2, the CPU in the control algorithm module retrieves the electrical quantity signals required by the control algorithm from memory, completes the control operation of the inner and outer loop controllers, calculates and generates the modulation voltage signal required by the converter, and stores the modulation voltage signal in memory. The time for the modulation voltage signal to be stored in memory is time T3. Due to the certain task fluctuation of the control operation, the time for the modulation voltage signal to be stored in memory fluctuates, but the fluctuation range (from T2 to T3) is within 10μs.

[0044] (5) At time T4, the modulation signal transmission module retrieves the converter modulation voltage signal from the memory via the 2.5Gbps PCIe bus and transmits it to the valve control device via Gigabit Ethernet.

[0045] The duration from T2 to T4 is the time for the modulation signal to be transmitted at regular intervals, such as... Figure 2As shown, it equals the maximum duration from T2 to T3 plus the reserved time; the maximum duration from T2 to T3 is determined through testing and statistical analysis of the converter station control system; based on the statistical analysis results, the maximum duration from T2 to T3 can be determined, and the control operation time included in this maximum duration is the maximum duration required for control operation;

[0046] Because the control operation has a certain degree of task fluctuation, in order to ensure that the control operation has been completed when the modulation signal transmission module retrieves the converter modulation voltage signal from memory at time T4, a certain amount of time needs to be reserved, which is the duration from T3 to T4.

[0047] The time interval from T2 to T4 is the link delay of the converter station control system.

[0048] II. Specific embodiments of the modulation voltage signal timing transmission method of the present invention are as follows:

[0049] Example 2

[0050] The modulation voltage signal timing transmission method of this embodiment adopts the modulation voltage signal timing transmission system of Embodiment 1, and includes the following steps:

[0051] (1) The electrical quantity acquisition module acquires digital electrical quantity signals and analog electrical quantity signals in each control cycle. The FPGA in the electrical quantity acquisition module performs A / D conversion on the acquired analog electrical quantity signals. Then, the FPGA reassembles the converted digital signal and the acquired digital electrical quantity signals into electrical quantity signals required by the control algorithm in a fixed arrangement order. The electrical quantity acquisition module actively transmits the electrical quantity signals required by the control algorithm to the storage unit of the control algorithm module through the hardware interrupt line, and at the same time transmits the start signal to the modulation signal transmission module. The electrical quantity signals include the MSI interrupt signal.

[0052] (2) When the control algorithm module receives the MSI interrupt signal in each control cycle, the processing unit extracts the electrical quantity signal from the storage unit, then calculates and generates the modulation voltage signal required by the converter and stores it in the storage unit.

[0053] (3) When the modulation signal transmission module receives the start signal in each control cycle and reaches the predetermined time, it extracts the modulation voltage signal from the storage unit and transmits it to the valve control device. The predetermined time is equal to the sum of the maximum value of the transmission storage time in all control cycles and the reserved time. The transmission storage time is the time from when the electrical quantity acquisition module starts to send the electrical quantity signal to the control algorithm module to when the modulation voltage signal is stored in the storage unit.

[0054] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of this application can be implemented in various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0055] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0056] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0057] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0058] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0059] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A system for timing the transmission of modulated voltage signals, characterized in that, It includes an electrical quantity acquisition module, a control algorithm module, and a modulation signal transmission module; the control algorithm module includes a processing unit and a storage unit; The electrical quantity acquisition module is used to acquire the electrical quantity signals required by the control algorithm in each control cycle, and then actively transmit the electrical quantity signals to the storage unit of the control algorithm module, while transmitting the start signal to the modulation signal transmission module. The process of acquiring electrical quantity signals by the electrical quantity acquisition module includes: the digital electrical quantity signal acquisition unit of the electrical quantity acquisition module is used to acquire digital electrical quantity signals; the analog electrical quantity signal acquisition unit of the electrical quantity acquisition module is used to acquire analog electrical quantity signals; the electrical quantity signal processing unit of the electrical quantity acquisition module is used to perform A / D conversion on the analog electrical quantity signals; and the converted digital signal and the acquired digital electrical quantity signals are reassembled into the electrical quantity signals according to a fixed arrangement order; the electrical quantity signals also include MSI interrupt signals; The processing unit is used to extract the electrical quantity signal from the storage unit when the control algorithm module receives the MSI interrupt signal in each control cycle, and then calculate and generate the modulation voltage signal required by the converter and store it in the storage unit. The modulation signal transmitting module extracts the modulation voltage signal from the storage unit and transmits it to the valve control device when a predetermined time is reached after receiving the start signal in each control cycle. The predetermined time is equal to the sum of the maximum value of the transmission and storage time in all control cycles and the reserved time. The maximum value of the transmission and storage time is the maximum time from when the control algorithm module receives the MSI interrupt signal to when the modulation voltage signal completes storage in the storage unit.

2. The modulation voltage signal timing transmission system as described in claim 1, characterized in that, The electrical quantity acquisition module sends the electrical quantity signals required by the control algorithm to the control algorithm module via the PCIe bus.

3. The modulation voltage signal timing transmission system as described in claim 1, characterized in that, The electrical quantity acquisition module transmits the start signal to the modulation signal transmission module via a hardware interrupt line.

4. A method for timing the transmission of a modulated voltage signal, employing the modulated voltage signal timing transmission system as described in any one of claims 1-3, comprising the following steps: (1) The electrical quantity acquisition module acquires the electrical quantity signals required by the control algorithm in each control cycle, and then actively transmits the electrical quantity signals to the storage unit of the control algorithm module, while transmitting the start signal to the modulation signal transmission module; the acquisition process of the electrical quantity signals includes: first acquiring digital electrical quantity signals and analog electrical quantity signals, then performing A / D conversion on the analog electrical quantity signals, and recombining the converted digital signals with the acquired digital electrical quantity signals in a fixed arrangement order to form the electrical quantity signals; the electrical quantity signals also include MSI interrupt signals; (2) When the control algorithm module receives the MSI interrupt signal in each control cycle, the processing unit extracts the electrical quantity signal from the storage unit, then calculates and generates the modulation voltage signal required by the converter and stores it in the storage unit. (3) When the modulation signal transmission module receives the start signal in each control cycle and reaches a predetermined time, it extracts the modulation voltage signal from the storage unit and transmits it to the valve control device; the predetermined time is equal to the sum of the maximum value of the transmission storage time in all control cycles and the reserved time, and the maximum value of the transmission storage time is the maximum time from when the control algorithm module receives the MSI interrupt signal to when the modulation voltage signal is stored in the storage unit.

5. In the method for timing the transmission of modulated voltage signals as described in claim 4, the electrical quantity acquisition module sends the electrical quantity signals required by the control algorithm to the control algorithm module via the PCIe bus.

6. In the method for timing the transmission of modulated voltage signals as described in claim 4, the electrical quantity acquisition module transmits the start signal to the modulation signal transmission module via a hardware interrupt line.

Images