PCS parallel operation clock synchronization method, storage medium and PCS parallel operation system

Abstract

The invention discloses a PCS parallel operation clock synchronization method, a storage medium and a PCS parallel operation system.The PCS parallel operation clock synchronization method comprises the steps that carrier signals are extracted from a power line, and beacon frames in the carrier signals are extracted; and updating the local time according to the timestamp information of the beacon frame so as to realize clock synchronization. According to the method, the problems of poor expansibility and relatively high delay in the prior art are solved through a broadband power line carrier technology, and a high-precision beacon timestamp is provided; the energy storage converters in the parallel operation state can update the local time of the energy storage converters through the timestamp information so as to realize high-precision clock synchronization.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage converters, and in particular to a PCS parallel clock synchronization method, a storage medium and a PCS parallel system. Background Art

[0002] The current PCS multi-machine control solutions include master-slave control, droop control, and distributed control. Droop control has problems such as slow response, over-compensation, under-compensation, and easy circulation because the multiple machines cannot communicate with each other. Both master-slave control and distributed control require communication links.

[0003] Common multi-machine communication solutions include: wired and wireless. However, the existing wired communication method requires rewiring to add new PCS units, which has poor scalability. Wireless communication has high communication delay, is easily physically isolated, and requires the addition of special network equipment. At present, the high communication delay and ultra-high precision clock synchronization problems during PCS parallel operation need to be solved urgently. Summary of the invention

[0004] The main purpose of the present invention is to provide a PCS parallel clock synchronization method, aiming to solve the problems of high communication delay and ultra-high precision clock synchronization during PCS parallel operation.

[0005] To achieve the above object, the present invention proposes a PCS parallel clock synchronization method, which includes: Extracting a carrier signal from the power line and extracting a beacon frame from the carrier signal; According to the timestamp information of the beacon frame, the local time is updated to achieve clock synchronization.

[0006] Preferably, updating the local time according to the timestamp information of the beacon frame to achieve clock synchronization includes: Get the sender count value in the timestamp information; Latch the local count value and obtain the difference between the sender count value and the local count value; The local count value is adjusted according to the difference so that the local count value is equal to the sending end count value.

[0007] Preferably, the extracting of the carrier signal from the power line then comprises: Extract the data signal with the same area code as the local station in the carrier signal; comparing a local MAC address with the MAC address group in the data signal; If there is a MAC address in the MAC address group that is smaller than the local MAC address, update the local time according to the timestamp information in the beacon frame corresponding to the MAC address; A beacon frame including the local time is sent to the power line.

[0008] Preferably, the comparing the local MAC address with the MAC address group in the data signal then comprises: If the local MAC address is smaller than any value in the MAC address group, a step of sending a beacon frame including the local time to the power line is performed.

[0009] Preferably, the beacon frame further includes PWM parameters; Extract the beacon frame from the carrier signal, followed by: According to the PWM parameters in the beacon frame of the same area number as the local machine, the PWM parameters of the local machine are synchronized to suppress the high-frequency circulation between the PCSs of the same area number.

[0010] Preferably, the beacon frame further includes: three-phase voltage zero-crossing time and grid frequency information; Extract the beacon frame from the carrier signal, followed by: According to the three-phase voltage zero-crossing time and grid frequency information in the beacon frame, the three-phase voltage zero-crossing time and grid frequency information of the local machine are synchronized to solve the low-frequency circulating current caused by the phase difference of each PCS.

[0011] Preferably, the beacon frame also includes: power parameters and load rate Extracting the carrier signal from the power line, followed by: Extract all beacon frames with local area code from the carrier signal; Calculating an average load rate of the load rates in the beacon frames; According to the average load rate, the load rate of the local machine is synchronized to achieve a nearly consistent load rate for the PCSs in the same area code.

[0012] The present invention further provides a storage medium, on which a PCS parallel clock synchronization program is stored. When the PCS parallel clock synchronization program is executed by a processor, the steps of the PCS parallel clock synchronization method are implemented.

[0013] The present invention also provides a PCS parallel system, the PCS parallel system comprising: a plurality of energy storage converters connected via power lines; The energy storage converter receives the carrier signal output by other energy storage converters through the power line, and extracts the beacon frame with the same station area code as the energy storage converter from the carrier signal; When the MAC address of the energy storage converter is greater than the MAC address corresponding to any one of the beacon frames, the energy storage converter updates the local time using the timestamp information included in the beacon frame corresponding to the minimum MAC address.

[0014] Preferably, the energy storage converter comprises: a battery pack, a three-phase inverter rectifier bridge, a three-phase LCL filter circuit, a coupling module and a control module; The input end of the three-phase inverter rectifier bridge is connected to the battery pack, and the output end is connected to the input end of the three-phase LCL filter circuit; the output end of the three-phase LCL filter circuit is connected to the first input end of the coupling module; the output end of the coupling module is connected to the power grid; The battery pack is used to provide a DC voltage; the control module is connected to the three-phase inverter rectifier bridge and the second input end of the coupling module respectively; the control module is used to control the on / off of the power switch in the three-phase inverter rectifier bridge and output a data signal to the coupling module; the coupling module modulates the data signal to generate a broadband carrier signal, and couples the broadband carrier signal to output it to the power grid.

[0015] The present invention provides a PCS parallel clock synchronization method, a storage medium and a PCS parallel system, wherein the PCS parallel clock synchronization method comprises: extracting a carrier signal from a power line and extracting a beacon frame in the carrier signal; updating the local time according to the timestamp information of the beacon frame to achieve clock synchronization. The present invention solves the problems of poor scalability and high delay in the prior art through broadband power line carrier technology, and provides a high-precision beacon timestamp; the energy storage converter in the parallel state can update its local time through the timestamp information to achieve high-precision clock synchronization. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0017] Figure 1 A schematic diagram of the steps of an embodiment of a PCS parallel clock synchronization method of the present invention; Figure 2 A schematic diagram of the steps of another embodiment of the PCS parallel clock synchronization method of the present invention; Figure 3 A schematic diagram of the steps of another embodiment of the PCS parallel clock synchronization method of the present invention; Figure 4 A schematic diagram of the structure of another embodiment of the PCS parallel clock synchronization method of the present invention; Figure 5 It is a structural schematic diagram of an embodiment of a PCS parallel system of the present invention.

[0018] Description of Figure Numbers:

[0019] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0022] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0024] The power conversion system (PCS) is a crucial device in the energy storage system. It is mainly responsible for realizing the AC / DC bidirectional conversion of electric energy to control the charging and discharging process of the energy storage battery pack.

[0025] The current PCS multi-machine control solutions include master-slave control, droop control, and distributed control. Droop control has problems such as slow response, over-compensation and under-compensation, and easy circulation because the multiple machines cannot communicate with each other. Both master-slave control and distributed control require communication links.

[0026] When multiple machines are connected in parallel and use the VF control strategy, a parallel line is required. Common multi-machine communication solutions are: (1) Wired communication method: Wiring is performed between multiple PCSs for communication, such as RS-485 and CAN bus. However, it is easy to understand that the method of wiring between PCSs has the disadvantage of poor scalability. Adding or reducing PCSs between a PCS group requires rewiring.

[0027] (2) Wireless communication: Multiple PCSs communicate with each other using wireless networks, such as Ethernet, modem, or devicenet. However, this communication method requires the installation of special network equipment; and wireless methods (wifi, zigbee, bluetooth) have high communication delays and are easily physically isolated. For example, the signal in the basement is poor.

[0028] In parallel operation, PCS needs to maintain a high degree of synchronization and coordination. This helps ensure that the output current and voltage between each device can be consistent, thereby avoiding problems such as circulating current and resonance. PWM is the abbreviation of pulse width modulation, which is a technology widely used in the field of power electronics. It controls the waveform and size of the output voltage or current by adjusting the duty cycle of the switch tube (that is, the ratio of the square wave high level time to the period). In PCS, PWM technology is used to control inverters and DC converters to achieve high-precision power conversion. The accuracy of clock synchronization in the above communication method is lower than the millisecond level. Even if (PWM) carrier synchronization technology is used, phase differences may occur due to various factors (such as delay, jitter, etc.).

[0029] Higher communication delay and lower precision clock synchronization will lead to poor synchronization of PCS parallel operation and low overall system performance and stability.

[0030] The present invention provides a PCS parallel clock synchronization method, which uses broadband power line carrier technology to directly couple communication signal outputs on the power line; compared with wired communication, directly coupling communication signals on the power line can avoid adding or reducing changes in PCS device wiring; compared with wireless communication, the energy path and the signal path are the same, and there is a signal wherever there is electricity. In addition, the accuracy of the broadband carrier beacon timestamp reaches the sub-microsecond or even nanosecond level, which is much higher than the PWM signal period of PCS, and clock synchronization can be completed. Compared with PWM carrier synchronization, high-speed ADC and complex algorithms are not required. Based on multi-machine communication, unified scheduling can be performed, which can solve the problems of high and low frequency circulation. In addition, this solution adopts a decentralized structure, and the online and offline of PCS equipment has little impact on the entire network.

[0031] High-precision clock synchronization is of great significance to PCS parallel clock synchronization, mainly in the following aspects: 1. Ensure data consistency and accuracy. In a PCS system, each component may generate data with timestamps. High-precision clock synchronization can ensure the accuracy of these timestamps, so that the data recorded by different components are consistent in the time dimension, which facilitates subsequent data analysis and processing.

[0032] 2. Improve system stability and security. Since clock synchronization ensures the uniformity and accuracy of time, it can reduce false alarms caused by time differences. This helps reduce the false alarm rate of the system and improve the overall stability of the system. In scenarios such as concurrent control, the order of time is crucial for decision-making. High-precision clock synchronization can avoid operational errors or system failures caused by time conflicts, thereby improving the security and reliability of the system.

[0033] Reference Figure 1 The present invention discloses a PCS parallel clock synchronization method, the PCS parallel clock synchronization method comprising: Step S10, extracting a carrier signal from the power line, and extracting a beacon frame from the carrier signal; Step S20: Update the local time according to the timestamp information of the beacon frame to achieve clock synchronization.

[0034] It should be noted that the executor of this method is the energy storage inverter (PCS, Power Conversion System). In this scheme, the energy storage inverters running in parallel communicate through power lines. The energy storage inverter couples the data signal into the carrier signal and outputs it to other energy storage inverters through the power line. For the process of extracting the carrier signal, the energy storage inverter that outputs the data signal can be called a sending energy storage inverter, and the energy storage inverter that receives the data signal can be called a receiving energy storage inverter. It is easy to obtain that there can be multiple receiving energy storage inverters receiving the data signal of the same output energy storage inverter. In addition, it should be noted that the receiving energy storage inverter and the sending energy storage inverter are not fixed, but are specifically determined according to the transmission parties and direction of the data signal.

[0035] Since the accuracy of broadband carrier beacon timestamps reaches the sub-microsecond or even nanosecond level, which is much higher than the PWM signal period of PCS, the use of broadband power carrier to transmit clock information can avoid phase differences in the output waveforms of PCSs running in parallel. The data information may include beacon frames, data frames, confirmation frames, and / or command frames. In addition, the communication cost of broadband power carrier modules is low, which can reduce the cost of PCS parallel operation.

[0036] Beacon frames are often used to synchronize devices in a network. In wireless networks or communication systems that require precise time control, beacon frames can be used as a time reference to help devices calibrate their internal clocks and ensure that all devices operate within the same time frame. After receiving the beacon frame, the node will join the network as specified by the coordinator and send and receive data at specified time intervals. This mechanism helps reduce conflicts and improve data transmission efficiency. Beacon frames can also carry configuration information, status updates, or other management instructions about the network. By sending beacon frames regularly, network devices can exchange information with each other to maintain the stability and performance of the network.

[0037] The beacon frame includes timestamp information; in order to achieve high-precision clock synchronization, after extracting the beacon frame from the carrier signal, the receiving energy storage inverter can update the local time according to the timestamp information of the beacon frame to achieve clock synchronization. Specifically, the timestamp information includes the time message when the sending energy storage inverter sends the carrier signal. The receiving energy storage inverter synchronizes its local time according to the time message to complete clock synchronization.

[0038] Reference Figure 2 In one embodiment, updating the local time according to the timestamp information of the beacon frame to achieve clock synchronization includes: Step S210, obtaining the sending end count value in the timestamp information; Step S220, latching the local count value, and obtaining the difference between the sender count value and the local count value; Step S230: Adjust the local count value according to the difference so that the local count value is equal to the sending end count value.

[0039] It is easy to see that in this embodiment, the energy storage converter uses the count value for clock synchronization. This method achieves the synchronization of the clocks of both parties by comparing and adjusting the count values ​​of the sending end and the receiving end. Specifically, the sending energy storage converter and the receiving energy storage converter each maintain a counter (or clock counter). This counter increments at a certain frequency, and each increment represents the passage of a time unit (such as milliseconds, microseconds, etc.).

[0040] The transmitting energy storage converter sends the current count value as a synchronization signal to the receiving end. This synchronization signal can be included in a specific data frame, such as a beacon frame. After receiving the synchronization signal, the receiving energy storage converter compares the count value in it with its own count value. By calculating the difference between the two, the clock deviation between the transmitting end and the receiving end can be determined. Based on the comparison results, the receiving energy storage converter adjusts its own clock to reduce or eliminate the deviation from the clock signal. This adjustment can be immediate or smooth to avoid sudden clock changes affecting data transmission.

[0041] The present invention provides a PCS parallel clock synchronization method, which includes: extracting a carrier signal from a power line and extracting a beacon frame in the carrier signal; updating the local time according to the timestamp information of the beacon frame to achieve clock synchronization. The present invention solves the problems of poor scalability and high delay in the prior art through broadband power line carrier technology, and provides a high-precision beacon timestamp; the energy storage converter in the parallel state can update its local time through the timestamp information to achieve high-precision clock synchronization.

[0042] It is easy to find that due to the use of power lines to transmit data information, there are multiple energy storage converters connected to the same power grid, belonging to different groups. The energy storage converters in the same group work closely together. If the energy storage converters in the group are adjusted according to the data information sent by the energy storage converters outside the group transmitted by the power lines, it may cause confusion and overall performance degradation. In order to overcome this problem, this solution uses the station area code for identification.

[0043] Reference Figure 3 In one embodiment, the extracting of the carrier signal from the power line then comprises: Step S110, extracting the data signal with the same area code as the local station from the carrier signal; Step S120, comparing the local MAC address with the MAC address group in the data signal; Step S130: If there is a MAC address smaller than the local MAC address in the MAC address group, update the local time according to the timestamp information in the beacon frame corresponding to the MAC address; Step S140: Send a beacon frame including the local time to the power line.

[0044] It should be noted that in order to prevent PCSs in different areas from being missynchronized, each PCS is pre-set with its own area number (SNID) and independent MAC under the area number after installation. Before synchronization, the PCS first listens to all MAC addresses in the data signal under the same SNID. If there is a node with a smaller MAC address than its own, it calibrates the clock according to the timestamp information in the beacon frame corresponding to the node with the smallest MAC address, keeps synchronization with it, and then sends its own beacon frame to the power line. This ensures the clock synchronization of the entire network.

[0045] In addition, in this embodiment, if the PCS under the same area value is offline, it is only necessary to re-compare the device MAC addresses under the area value to obtain the PCS with the smallest MAC address, and use the clock of the PCS to complete the clock synchronization of the PCS belonging to the same area value.

[0046] If at a certain moment, a PCS is added to the PSC group to which the area value belongs, it is only necessary to re-compare the device MAC addresses under the area value to obtain the PCS with the smallest MAC address, and use the clock of the PCS to complete the clock synchronization of the PCSs belonging to the same area value.

[0047] That is, no matter whether the PCS device is offline or online, it is only necessary to re-determine the PCS with the smallest MAC address and use the clock of the PCS to complete the clock synchronization of the PCSs belonging to the same station area value; decentralization is achieved.

[0048] Reference Figure 4 At time t1 in the figure, PCS1 is offline. Then PCS2 is no longer calibrated, and PCS2 becomes the alignment target of PCSs in the same area code. Decentralization is achieved.

[0049] The comparing of the local MAC address and the MAC address group in the data signal then comprises: If the local MAC address is smaller than any value in the MAC address group, a step of sending a beacon frame including the local time to the power line is performed.

[0050] It is easy to understand that if the local MAC address is the smallest MAC address under the area code, other PCS under the same area code need to synchronize their clocks according to the local clock; that is, a beacon frame including the local time is sent to the power line so that other PCS under the same area code can synchronize their clocks according to the local time.

[0051] In addition, the beacon frame may carry other information in addition to the clock information.

[0052] In one embodiment, the beacon frame further includes PWM parameters; Extract the beacon frame from the carrier signal, followed by: According to the PWM parameters in the beacon frame of the same area number as the local machine, the PWM parameters of the local machine are synchronized to suppress the high-frequency circulation between the PCSs of the same area number.

[0053] It should be noted that in the energy storage converter in parallel operation, the transmitted PWM (pulse width modulation) parameters play a vital role. These parameters are mainly used to accurately control the working state of the converter to achieve high efficiency and stability in the storage, conversion and release of electric energy. In the parallel operation state, multiple energy storage converters need to work together to maintain the balance of the power system. By transmitting key information such as PWM parameters, intelligent scheduling and coordinated control between converters can be achieved to ensure the stable operation of the entire system.

[0054] High-frequency circulating current is usually caused by uneven current distribution or improper control strategy between parallel converters, which may lead to reduced system efficiency, overheating and even damage to equipment. Ensure that all parallel energy storage converters receive and synchronize the same PWM signal. This helps reduce high-frequency circulating current caused by asynchronous signals. Accurate coordination between converters can be achieved through precise clock synchronization and signal distribution mechanisms.

[0055] The beacon frame also includes: three-phase voltage zero-crossing time and power grid frequency information; Extract the beacon frame from the carrier signal, followed by: According to the three-phase voltage zero-crossing time and grid frequency information in the beacon frame, the three-phase voltage zero-crossing time and grid frequency information of the local machine are synchronized to solve the low-frequency circulating current caused by the phase difference of each PCS.

[0056] It should be noted that by sharing the information of the three-phase voltage zero-crossing moment, each energy storage converter can obtain the accurate phase of the grid in real time. This helps them adjust their own output phase to ensure strict synchronization with the grid. When the outputs of all converters are synchronized with the grid, the phase difference between them will be greatly reduced or even eliminated, thus avoiding the low-frequency circulating current caused by phase asynchrony; grid frequency information is another important synchronization reference. By sharing this information, each energy storage converter can ensure that they are all operating at the same frequency. This not only helps to reduce phase errors, but also improves the overall stability and reliability of the system.

[0057] In addition, after knowing the phase and frequency of the power grid, the energy storage converter can use more precise modulation strategies (such as space vector pulse width modulation SVPWM) to generate the output voltage waveform. These strategies can more accurately control the output voltage phase and amplitude of the inverter, thereby reducing the harmonic content and phase deviation, and thus reducing the generation of low-frequency circulating current.

[0058] The beacon frame also includes: power parameters and load rate Extracting the carrier signal from the power line, followed by: Extract all beacon frames with local area code from the carrier signal; Calculating an average load rate of the load rates in the beacon frames; According to the average load rate, the load rate of the local machine is synchronized to achieve a nearly consistent load rate for the PCSs in the same area code.

[0059] It is easy to understand that the beacon frame also includes power parameters and load rates, which is helpful for understanding the average load rate of each energy storage inverter; calculating the average load rate of the load rate in the beacon frame, and synchronizing the load rate of the local machine according to the average load rate, can achieve PCS load balancing in parallel operation and prevent individual nodes from being overloaded. By adjusting the load of each energy storage inverter to the average load rate, it can be ensured that each device operates in a relatively balanced working state. This helps to avoid the situation where some devices are overloaded while other devices are idle, thereby improving the stability and reliability of the entire system.

[0060] The present invention further provides a storage medium, on which a PCS parallel clock synchronization program is stored. When the PCS parallel clock synchronization program is executed by a processor, the steps of the PCS parallel clock synchronization method are implemented.

[0061] The present invention also provides a PCS parallel system, the PCS parallel system comprising: a plurality of energy storage converters connected via power lines; The energy storage converter receives the carrier signal output by other energy storage converters through the power line, and extracts the beacon frame with the same station area code as the energy storage converter from the carrier signal; When the MAC address of the energy storage converter is greater than the MAC address corresponding to any one of the beacon frames, the energy storage converter updates the local time using the timestamp information included in the beacon frame corresponding to the minimum MAC address.

[0062] Optional, see Figure 5 , the energy storage converter comprises: a battery pack 10, a three-phase inverter rectifier bridge 20, a three-phase LCL filter circuit 30, a coupling module 40 and a control module 50; The input end of the three-phase inverter rectifier bridge 20 is connected to the battery pack 10, and the output end is connected to the input end of the three-phase LCL filter circuit 30; the output end of the three-phase LCL filter circuit 30 is connected to the first input end of the coupling module 40; the output end of the coupling module 40 is connected to the power grid; The battery pack 10 is used to provide a DC voltage; the control module 50 is respectively connected to the second input end of the three-phase inverter rectifier bridge 20 and the coupling module 40; the control module 50 is used to control the on / off of the power switch in the three-phase inverter rectifier bridge 20 and output a data signal to the coupling module 40; the coupling module 40 modulates the data signal to generate a broadband carrier signal, and couples the broadband carrier signal to the power grid.

[0063] It should be noted that the main function of the three-phase LCL filter circuit 30 is to filter out high-frequency harmonics and noise in the power system. When the alternating current output by the energy storage converter passes through the three-phase LCL filter circuit 30, the high-frequency harmonic components are effectively suppressed, thereby improving the quality of the output electric energy. This helps to reduce harmonic pollution in the power grid, protect power equipment from damage, and improve the stability and reliability of the entire power system. In addition, through the processing of the three-phase LCL filter circuit 30, the current or voltage waveform output by the energy storage converter is smoother and more stable, reducing fluctuations and distortion. This is of great significance for improving the power supply quality of the power grid and meeting users' demand for high-quality electric energy.

[0064] The three-phase LCL filter circuit 30 can not only effectively filter out high-frequency harmonics and noise, but also isolate the influence of external electromagnetic interference on the output signal of the energy storage converter to a certain extent. This helps to improve the anti-interference ability and stability of the system; by coupling the broadband carrier signal with the output signal of the energy storage converter and then outputting it to the power grid, it can avoid direct impact or damage to the power grid.

[0065] The control module 50 may include a controller such as an MCU, an FPGA or a SOC.

[0066] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A PCS parallel clock synchronization method, characterized in that: The PCS parallel clock synchronization method comprises: Extracting a carrier signal from the power line and extracting a beacon frame from the carrier signal; According to the timestamp information of the beacon frame, the local time is updated to achieve clock synchronization.

2. The PCS parallel clock synchronization method according to claim 1, characterized in that: The updating of the local time according to the timestamp information of the beacon frame to achieve clock synchronization includes: Get the sender count value in the timestamp information; Latch the local count value and obtain the difference between the sender count value and the local count value; The local count value is adjusted according to the difference so that the local count value is equal to the sending end count value.

3. The PCS parallel clock synchronization method according to claim 2, characterized in that: The method further comprises extracting a carrier signal from the power line, and then comprising: Extract the data signal with the same area code as the local station in the carrier signal; comparing a local MAC address with the MAC address group in the data signal; If there is a MAC address in the MAC address group that is smaller than the local MAC address, update the local time according to the timestamp information in the beacon frame corresponding to the MAC address; A beacon frame including the local time is sent to the power line.

4. The PCS parallel clock synchronization method according to claim 3, characterized in that: The comparing of the local MAC address and the MAC address group in the data signal then comprises: If the local MAC address is smaller than any value in the MAC address group, a step of sending a beacon frame including the local time to the power line is performed.

5. The PCS parallel clock synchronization method according to any one of claims 1 to 4, characterized in that: The beacon frame also includes PWM parameters; Extract the beacon frame from the carrier signal, followed by: According to the PWM parameters in the beacon frame of the same area number as the local machine, the PWM parameters of the local machine are synchronized to suppress the high-frequency circulation between the PCSs of the same area number.

6. The PCS parallel clock synchronization method according to any one of claims 1 to 4, characterized in that: The beacon frame also includes: three-phase voltage zero-crossing time and power grid frequency information; Extract the beacon frame from the carrier signal, followed by: According to the three-phase voltage zero-crossing time and grid frequency information in the beacon frame, the three-phase voltage zero-crossing time and grid frequency information of the local machine are synchronized to solve the low-frequency circulating current caused by the phase difference of each PCS.

7. The PCS parallel clock synchronization method according to any one of claims 1 to 4, characterized in that: The beacon frame also includes: power parameters and load rate Extracting the carrier signal from the power line, followed by: Extract all beacon frames with local area code from the carrier signal; Calculating an average load rate of the load rates in the beacon frames; According to the average load rate, the load rate of the local machine is synchronized to achieve a nearly consistent load rate for the PCSs in the same area code.

8. A storage medium, characterized in that: The storage medium stores a PCS parallel clock synchronization program, and when the PCS parallel clock synchronization program is executed by the processor, the steps of the PCS parallel clock synchronization method according to any one of claims 1 to 7 are implemented.

9. A PCS parallel system, characterized in that: The PCS parallel system comprises: a plurality of energy storage converters connected via power lines; The energy storage converter receives the carrier signal output by other energy storage converters through the power line, and extracts the beacon frame with the same station area code as the energy storage converter from the carrier signal; When the MAC address of the energy storage converter is greater than the MAC address corresponding to any one of the beacon frames, the energy storage converter updates the local time using the timestamp information included in the beacon frame corresponding to the minimum MAC address.

10. The PCS parallel system according to claim 9, characterized in that: The energy storage converter comprises: a battery pack, a three-phase inverter rectifier bridge, a three-phase LCL filter circuit, a coupling module and a control module; The input end of the three-phase inverter rectifier bridge is connected to the battery pack, and the output end is connected to the input end of the three-phase LCL filter circuit; the output end of the three-phase LCL filter circuit is connected to the first input end of the coupling module; the output end of the coupling module is connected to the power grid; The battery pack is used to provide a DC voltage; the control module is connected to the three-phase inverter rectifier bridge and the second input end of the coupling module respectively; the control module is used to control the on / off of the power switch in the three-phase inverter rectifier bridge and output a data signal to the coupling module; the coupling module modulates the data signal to generate a broadband carrier signal, and couples the broadband carrier signal to output it to the power grid.

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