Power internet of things wireless communication time synchronization method, control side and terminal side

Abstract

The present disclosure belongs to the technical field of nuclear power and specifically relates to a power Internet of Things wireless communication time synchronization method, a control side and a terminal side. In the present disclosure, if the control side determines that the current time enters a time synchronization period, and if the current alternating voltage phase angle is a preset phase angle, the working frequency point is switched to a time synchronization frequency point, and a time synchronization broadcast is sent at the time synchronization frequency point, so that the terminal side of the Internet of Things synchronizes time with the control side. The voltage phase angle obtained by sampling the alternating power supply voltage or the power Internet of Things device is introduced as a technical means of a time synchronization parameter, so that the Internet of Things system device has stable and reliable information transmission time. The present disclosure overcomes the difficulty of current power Internet of Things wireless communication time synchronization, solves the problem that the traditional Internet of Things device can only rely on the internal clock synchronization of the device, and effectively avoids the disadvantage of large Internet time offset.

Description

Technical Field

[0001] This invention belongs to the field of IoT TDMA communication technology, specifically relating to a time synchronization method for wireless communication in the power IoT, the control side, and the terminal side. Background Technology

[0002] Current wireless communication technologies can employ multiple access methods such as FDMA, TDMA, CSMA, and CDMA. Among them:

[0003] FDMA (Frequency Division Multiple Access): This method divides the total frequency band into different smaller channels and allocates them to different users, with each user having their own allocated smaller frequency band. The advantages of this multiple access method are its relative simplicity, ease of implementation, and mature technology; however, its disadvantages are also obvious: low frequency utilization and small capacity. It was used in early 1G wireless communication but is now rarely used.

[0004] TDMA (Time Division Multiple Access): This multiple access method, based on Frequency Division Multiple Access, divides time periods within each small frequency band into smaller time slots and allocates them to different users. This multiple access method has many advantages, including large communication capacity and high frequency utilization; however, TDMA has disadvantages such as complex technical implementation and strict synchronization requirements. This method was used in traditional 2G communication (GSM).

[0005] CSMA (Carrier Sense Multiple Access): In CSMA, the system listens for communication signals on the specified frequency before transmitting wirelessly. If a signal is present, the system waits for the wireless communication to end and the channel to become idle before immediately transmitting the message. This method avoids most collisions, but it cannot resolve collisions caused by two or more nodes transmitting data simultaneously. Because wireless communication devices require state switching between transmission and reception, the node itself cannot detect collisions when they occur.

[0006] CDMA (Code Division Multiple Access): This technology uses spread spectrum code division multiple access. All users obtain service channels on the same frequency band at the same time, based on different codes. Its advantages are maximum capacity, high frequency utilization, and good communication quality. CDMA has been widely used in wireless communication networks above 3G, but in IoT applications, this multiple access method started too late and has a small user base.

[0007] In the power Internet of Things (IoT), from traditional 433MHz small wireless to the current LoRa low-power wireless communication method, TDMA is widely used. Because TDMA has very high time synchronization requirements, time synchronization deviations can lead to message collisions and communication failures. However, the various terminals, gateways, servers, and other devices in wireless communication lack effective time synchronization methods. Especially for IoT terminal devices, to conserve power, they cannot send / receive synchronization messages at high frequencies, leading to rapid and significant time discrepancies within multiple devices. Often, the only solution is to add sufficient margin during time slot allocation to prevent collisions, which greatly reduces wireless communication speed and response time. Therefore, it is urgent to solve the time synchronization problem of various terminal devices in the power IoT. Summary of the Invention

[0008] To overcome the problems existing in related technologies, a method for wireless communication time synchronization in the power Internet of Things, as well as a control side and a terminal side, are provided.

[0009] According to one aspect of the present disclosure, an Internet of Things (IoT) wireless communication time synchronization method is provided, the method being applied to the control side of the IoT, the method comprising:

[0010] Step 10: When the control side determines that the current time has entered the time synchronization period, if it detects that the current AC voltage phase angle is a preset phase angle, it switches from the working frequency point to the time synchronization frequency point and sends a time synchronization broadcast at the time synchronization frequency point. The time synchronization broadcast is used to synchronize the time between the IoT terminal side and the control side. The IoT terminal side and the control side are located in the same AC power supply area.

[0011] Step 11: After the time synchronization broadcast is completed, the control side switches from the time synchronization frequency to the working frequency.

[0012] In one possible implementation, when there is no phase angle difference between the control side and the power supply, the control side includes a first phase angle detection module and a first communication module, and step 10 includes:

[0013] Step 100: When entering the time synchronization period at the current moment, the first phase angle detection module determines the input AC voltage phase angle;

[0014] Step 101: If the first phase angle detection module determines that the phase angle of the input AC voltage is a preset phase angle, it sends a first trigger signal to the first communication module.

[0015] Step 102: Upon receiving the first trigger signal, the first communication module switches from the operating frequency to the time synchronization frequency and sends a time synchronization broadcast at the time synchronization frequency.

[0016] In one possible implementation, when there is a phase angle difference between the control side and the power supply, the control side includes a first phase angle detection module, a first timer, and a first communication module, and step 10 further includes:

[0017] Step 103: When entering the time synchronization period at the current moment, the first phase angle detection module determines the phase angle of the input AC voltage;

[0018] Step 104: When the first phase angle detection module determines that the phase angle of the input AC voltage is a preset phase angle, it sends a first trigger signal to the first timer.

[0019] Step 105: When the first timer receives the first trigger signal, it causes a hardware interrupt on the control side until the time delay corresponding to the phase angle difference is reached, and then sends the second trigger signal to the first communication module.

[0020] Step 106: Upon receiving the second trigger signal, the first communication module switches from the operating frequency to the time synchronization frequency and sends a time synchronization broadcast at the time synchronization frequency.

[0021] In one possible implementation, the first phase angle detection module is a Fourier transform module, used to perform Fourier transform processing on the input AC voltage to determine the voltage phase angle of the input AC voltage; or

[0022] The preset phase angle is the zero-crossing phase angle, and the first phase angle detection module is a zero-point detection module used to detect the zero-crossing phase angle of the input AC voltage.

[0023] According to another aspect of the present disclosure, a time synchronization method for wireless communication in a power Internet of Things (IoT) is provided, the method being applied to an IoT terminal side, the method comprising:

[0024] Step 20: When the terminal enters the time synchronization period at the current moment, if it detects that the terminal has lost time synchronization with the control side, or that the time synchronization duration exceeds the preset duration, the time synchronization mode is activated.

[0025] Step 21: In time synchronization mode, if the terminal detects that the AC voltage phase angle is the preset phase angle, the timer is started and the operating frequency is switched to the time synchronization frequency. The time synchronization frequency is used to listen for time synchronization broadcasts.

[0026] Step 22: Upon receiving the time synchronization broadcast, the terminal obtains the timer's duration.

[0027] Step 23: The terminal side calibrates its time based on the time and timing duration obtained from the time broadcast parsing.

[0028] Step 24: After the time calibration on the terminal side is completed, switch from the time synchronization frequency point to the working frequency point.

[0029] In one possible implementation, when there is no phase angle difference between the terminal side and the power supply, the terminal side includes a second phase angle detection module and a second communication module, and step 21 includes:

[0030] Step 210: In time synchronization mode, the second phase angle detection module determines the phase angle of the input AC voltage;

[0031] Step 211: If the second phase angle detection module determines that the phase angle of the input AC voltage is the preset phase angle, it sends a first trigger signal to the second communication module.

[0032] Step 212: Upon receiving the first trigger signal, the second communication module switches from the operating frequency to the time synchronization frequency and listens for time synchronization broadcasts on the time synchronization frequency.

[0033] In one possible implementation, when there is a phase angle difference between the control side and the power supply, the control side includes a second phase angle detection module, a second timer, and a second communication module. Step 21 further includes:

[0034] Step 213: In time synchronization mode, the second phase angle detection module determines the phase angle of the input AC voltage;

[0035] Step 214: When the detection module determines that the phase angle of the input AC voltage is a preset phase angle, it sends a first trigger signal to the second timer.

[0036] Step 215: When the second timer receives the first trigger signal, it causes a hardware interrupt on the terminal side until the time delay corresponding to the phase angle difference is reached, and then sends the second trigger signal to the second communication module.

[0037] Step 216: Upon receiving the second trigger signal, the second communication module switches from the operating frequency to the time synchronization frequency and listens for time synchronization broadcasts on the time synchronization frequency.

[0038] In one possible implementation, the second phase angle detection module is a Fourier transform module, used to perform Fourier transform processing on the input AC voltage to determine the voltage phase angle of the input AC voltage; or

[0039] The preset phase angle is the zero-crossing phase angle, and the second phase angle detection module is a zero-point detection module used to detect the zero-crossing phase angle of the input AC voltage.

[0040] According to another aspect of the present disclosure, an Internet of Things (IoT) control side is provided, the control side including a first phase angle detection module, a first timer and a first communication module, the control side being configured to execute the above-described method applied to the IoT control side.

[0041] According to another aspect of the present disclosure, an Internet of Things (IoT) terminal side is provided, the terminal side including a second phase angle detection module, a second timer, and a second communication module, the terminal side being configured to execute the above-described method applied to the IoT terminal side.

[0042] The beneficial effects of this disclosure are as follows: In the IoT wireless communication time synchronization method disclosed herein, when the control side determines that the current time has entered a time synchronization period, if it detects that the current AC voltage phase angle is a preset phase angle, it switches from the operating frequency to the time synchronization frequency and sends a time synchronization broadcast at the time synchronization frequency, so that the IoT terminal side and the control side are synchronized in time. This disclosure introduces the AC power supply voltage or the voltage phase angle sampled and obtained by the power IoT device as a technical means of time synchronization, so that the IoT system devices have a stable and reliable information transmission and reception time. It overcomes the difficulties of current power IoT wireless communication time synchronization, solves the problem that traditional IoT devices can only rely on internal clock synchronization of the device and auxiliary network time synchronization, and effectively avoids the drawback of large time offset of the Internet. Attached Figure Description

[0043] Figure 1 This is a flowchart illustrating an IoT wireless communication time synchronization method applied to the IoT control side according to an exemplary embodiment.

[0044] Figure 2 This is a flowchart illustrating an IoT wireless communication time synchronization method applied to an IoT terminal side according to an exemplary embodiment. Detailed Implementation

[0045] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] In view of the aforementioned technical issues, the applicant has discovered in engineering practice that in the power Internet of Things (IoT), almost all IoT devices are powered by AC power (even if some IoT devices use DC power, their DC power is converted from AC power). Even devices that do not use mains power or measure electrical signals (such as electrical contact temperature measuring devices) may come into contact with low-voltage, medium-voltage, or even high-voltage live conductors, and can obtain voltage (electric field) data of high-voltage electrical equipment, thereby obtaining voltage phase angle (or zero-crossing point) signals.

[0047] Furthermore, wireless communication devices in the power Internet of Things (IoT) are generally distributed within a range of several hundred meters, with a maximum distance not exceeding several kilometers. In the power grid, the electric field (voltage) transmission speed reaches the speed of light. For the same AC power source, within a 10-kilometer range, the time deviation caused by phase angle error is typically around 0.033 milliseconds. This time error is almost negligible for wireless communication, and under steady-state conditions, the time deviation is determined only by distance and is not affected by other electrical loads. For different phases of the same AC power source, with a fixed phase difference of 120 degrees, the corresponding time difference is fixed once the phase is determined. For power sources of different voltage levels, which pass through transformers and other electrical devices, the phase may vary slightly due to the transformer's wiring method. For example, in a star-delta 11 connection, the same phases on the high and low voltage sides have a phase angle difference of 30 degrees, which is also fixed and does not change due to other factors.

[0048] In summary, for multiple IoT communication devices within the same AC power supply area, the voltage phase angle difference measured at any point in time is constant. Based on this, the IoT wireless communication time synchronization method disclosed herein introduces the AC power supply voltage or the voltage phase angle sampled by the power IoT device as the time synchronization parameter, so that each wireless IoT device (control side or terminal side) uses a fixed voltage phase angle time point as the wireless transmission and reception start time, thereby achieving high-precision time synchronization.

[0049] Figure 1 This is a flowchart illustrating an IoT wireless communication time synchronization method applied to an IoT control side according to an exemplary embodiment. The IoT control side can be, for example, a gateway, host computer, or communication system server in the IoT. This disclosure does not limit the type of IoT control side. Figure 1 As shown, the method may include:

[0050] Step 10: When the control side determines that the current time has entered the time synchronization period, if it detects that the current AC voltage phase angle is a preset phase angle, it switches from the working frequency point to the time synchronization frequency point and sends a time synchronization broadcast at the time synchronization frequency point. The time synchronization broadcast is used to synchronize the time between the IoT terminal side and the control side.

[0051] Step 11: After the time synchronization broadcast is completed, the control side switches from the time synchronization frequency to the working frequency.

[0052] This disclosure applies to power IoT devices that use a TDMA wireless communication system. The TDMA wireless communication system can be, for example, a 433MHz wireless communication device or a LoRa communication device. IoT devices (including the control side and the terminal side) usually have relatively complete wireless communication modules. Therefore, this disclosure does not require adding new wireless communication hardware. It is only necessary to allocate a frequency band as a time synchronization frequency point in the existing communication device. Normal business communication cannot be configured to this time synchronization frequency point.

[0053] In this disclosure, the control side can be equipped with high-precision time synchronization devices (such as GPS, Beidou or Internet time synchronization). In some independent systems, the control side may not need precise time synchronization, but only need each IoT terminal to keep time synchronized with the control side host.

[0054] For example, in step 10, the control side can preset multiple different time synchronization periods and continuously detect whether the current time has entered a time synchronization period. When the control side detects that the current time has entered a time synchronization period, it starts to collect the phase angle of the current input AC voltage at a preset frequency and determines whether the collected AC voltage phase angle is the preset phase angle. If the control side determines that the collected AC voltage phase angle is the preset phase angle, the control side can switch from the operating frequency to the time synchronization frequency and send a time synchronization broadcast at the time synchronization frequency.

[0055] In step 11, after the time synchronization broadcast ends, the control side can switch back from the time synchronization frequency to the operating frequency. The time synchronization broadcast is used to synchronize the time between the IoT terminal and the control side; it is sent periodically and does not accept responses from the terminal.

[0056] In the IoT wireless communication time synchronization method disclosed herein, when the control side determines that the current time has entered a time synchronization period, if it detects that the current AC voltage phase angle is a preset phase angle, it switches from the operating frequency to the time synchronization frequency and sends a time synchronization broadcast at the time synchronization frequency to synchronize the time between the IoT terminal and the control side. This disclosure introduces the AC power supply voltage or the voltage phase angle sampled and obtained by the power IoT device as a technical means of time synchronization, enabling IoT system devices to have stable and reliable information transmission and reception time. It overcomes the current difficulties in time synchronization of power IoT wireless communication and solves the problem that traditional IoT devices can only rely on internal clock synchronization and network time synchronization, effectively avoiding the drawback of large time offset in the Internet.

[0057] In one possible implementation, when there is no phase angle difference between the control side and the power supply, the control side may include a first phase angle detection module and a first communication module, and step 10 may include:

[0058] Step 100: When entering the time synchronization period at the current moment, the first phase angle detection module determines the input AC voltage phase angle;

[0059] Step 101: If the first phase angle detection module determines that the phase angle of the input AC voltage is a preset phase angle, it sends a first trigger signal to the first communication module.

[0060] Step 102: Upon receiving the first trigger signal, the first communication module switches from the operating frequency to the time synchronization frequency and sends a time synchronization broadcast at the time synchronization frequency.

[0061] Thus, this disclosure can achieve the acquisition of AC voltage phase angle and the triggering of time synchronization action through a simple structure using a first phase angle detection module and a first communication module, even when there is no phase angle difference between the control side and the power supply.

[0062] In one possible implementation, when there is a phase angle difference between the control side and the power supply, the control side includes a first phase angle detection module, a first timer, and a first communication module, and step 10 further includes:

[0063] Step 103: When entering the time synchronization period at the current moment, the first phase angle detection module determines the phase angle of the input AC voltage;

[0064] Step 104: When the first phase angle detection module determines that the phase angle of the input AC voltage is a preset phase angle, it sends a first trigger signal to the first timer.

[0065] In step 104, IoT communication terminals typically use microcontrollers as their processing core. Most microcontrollers have built-in high-precision, low-power timers that can be used directly. If the timer is insufficient, an external high-precision, low-power timer can be added.

[0066] Step 105: When the first timer receives the first trigger signal, it causes a hardware interrupt on the control side until the time delay corresponding to the phase angle difference is reached, and then sends the second trigger signal to the first communication module.

[0067] Step 106: Upon receiving the second trigger signal, the first communication module switches from the operating frequency to the time synchronization frequency and sends a time synchronization broadcast at the time synchronization frequency.

[0068] Thus, this disclosure can achieve AC voltage phase angle acquisition and timing action triggering through a simple structure using a first phase angle detection module, a first timer, and a first communication module, even when there is a phase angle difference between the control side and the power supply.

[0069] Figure 2 This is a flowchart illustrating an IoT wireless communication time synchronization method applied to an IoT terminal side according to an exemplary embodiment. The terminal side can be, for example, a mobile communication terminal or an electrical contact temperature measuring device, etc. This disclosure does not limit the type of the terminal side, such as... Figure 2 As shown, the method may include:

[0070] Step 20: When the terminal enters the time synchronization period at the current moment, if it detects that the terminal has lost time synchronization with the control side, or that the time synchronization duration exceeds the preset duration, the time synchronization mode is activated.

[0071] For example, in step 20, the time synchronization mode can be represented as the mode in which the terminal performs time synchronization operation. The terminal can perform periodic time synchronization, that is, when the current time enters the time synchronization period, the time synchronization mode is started; the terminal can also perform fault time synchronization, that is, when a time synchronization failure is detected, or when the time synchronization duration exceeds the preset duration, the time synchronization mode is started.

[0072] Step 21: In time synchronization mode, the terminal side can preset the frequency to collect the AC phase angle of the input. If the terminal side detects that the AC voltage phase angle is the preset phase angle, it starts the timer to start timing and switches from the working frequency point to the time synchronization frequency point to listen for time synchronization broadcasts.

[0073] Step 22: When the terminal receives the time synchronization broadcast, it can obtain the duration of the timer and parse the time synchronization broadcast to obtain the time synchronization time.

[0074] Step 23: The terminal can use the difference between the synchronized time and the timing duration as the calibration time and adjust the time on the terminal to the calibration time; or, if the timing duration is too short (e.g., the timing duration is less than the preset duration threshold), the synchronized time can be used directly as the calibration time.

[0075] Step 24: After time calibration is completed, the terminal can switch from the time synchronization frequency to the working frequency.

[0076] In the IoT wireless communication time synchronization method disclosed herein, the terminal side can enter the time synchronization mode through timed time synchronization or fault time synchronization trigger conditions, which can flexibly meet the different time synchronization needs of the terminal side. When the input AC voltage phase angle is detected to be a preset phase angle, the terminal switches from the operating frequency to the time synchronization frequency, receives the time synchronization broadcast, and realizes time calibration with the control side. This disclosure introduces the AC power supply voltage or the voltage phase angle sampled by the power IoT device as a technical means of time synchronization, so that the IoT system devices have stable and reliable information transmission and reception time. It overcomes the current difficulties in time synchronization of power IoT wireless communication and solves the problem that traditional IoT devices can only rely on internal clock synchronization and auxiliary network time synchronization, effectively avoiding the drawback of large time offset of the Internet.

[0077] In one possible implementation, when there is no phase angle difference between the terminal side and the power supply, the terminal side includes a second phase angle detection module and a second communication module, and step 21 includes:

[0078] Step 210: In time synchronization mode, the second phase angle detection module determines the phase angle of the input AC voltage;

[0079] Step 211: If the second phase angle detection module determines that the phase angle of the input AC voltage is the preset phase angle, it sends a first trigger signal to the second communication module.

[0080] Step 212: Upon receiving the first trigger signal, the second communication module switches from the operating frequency to the time synchronization frequency and listens for time synchronization broadcasts on the time synchronization frequency.

[0081] In one possible implementation, when there is a phase angle difference between the control side and the power supply, the control side includes a second phase angle detection module, a second timer, and a second communication module. Step 21 further includes:

[0082] Step 213: In time synchronization mode, the second phase angle detection module determines the phase angle of the input AC voltage;

[0083] Step 214: When the detection module determines that the phase angle of the input AC voltage is a preset phase angle, it sends a first trigger signal to the second timer.

[0084] Step 215: When the second timer receives the first trigger signal, it causes a hardware interrupt on the terminal side until the time delay corresponding to the phase angle difference is reached, and then sends the second trigger signal to the second communication module.

[0085] Step 216: Upon receiving the second trigger signal, the second communication module switches from the operating frequency to the time synchronization frequency and listens for time synchronization broadcasts on the time synchronization frequency.

[0086] For detailed explanations of steps 210 to 216, please refer to the descriptions of steps 100 to 106, which will not be repeated here.

[0087] In one possible implementation, the detection of the preset phase angle on the control side and the terminal side can be achieved, for example, by setting a Fourier transform module (software module) on the control side or the terminal side. The Fourier transform module performs Fourier transform processing on the input AC voltage signal to determine the voltage phase angle of the input AC voltage. Thus, the AC voltage phase angle is acquired through software.

[0088] In another possible implementation, the detection of preset phase angles on the control side and terminal side can be simplified to a zero-crossing point (points with phase angles of 0, 180, and 360 degrees) detection method. For power IoT devices (control side or terminal side) requiring wireless communication, a zero-crossing point detection module is configured to detect voltage phase angles of 0, 180, and 360 degrees. After detecting a zero-crossing point, a pulse signal is sent to trigger a hardware interrupt in the IoT device. By using simple methods such as zero-crossing point counting and on-chip timers, the start point of the time slot belonging to the power IoT device can be obtained, achieving precise time synchronization. Both zero-crossing point detection and phase detection can enable the time synchronization system to obtain simultaneous events.

[0089] In one application example, taking a domestic 50Hz industrial frequency AC power supply as an example, the following explanation is provided:

[0090] A 50Hz AC power supply generates a periodic sinusoidal signal with a phase angle ranging from 0 to 360 degrees, repeating every 20ms. At a phase angle of 0 or 180 degrees, the voltage is zero, electrically termed a zero-crossing point. To simplify system implementation, a zero-crossing detection module can be configured for each IoT device (including control and terminal sides). Each IoT device's module only detects the voltage zero-crossing point measured by that device. The zero-crossing point of one device in the communication system is used as the starting point of the time slot (typically the gateway device's zero-crossing point). The time difference between the zero-crossing points of other devices and this device's zero-crossing point is fixed, and time synchronization is achieved through internal timers within the devices. Therefore, time can be divided into time slots of 10ms or multiples of 10ms for wireless communication time synchronization of power IoT devices.

[0091] The zero-crossing detection module receives an AC voltage signal and detects zero crossings using a comparator. When a zero crossing occurs, the output signal changes, generating a square wave signal with a period of 20ms. This signal is input to a power IoT device. If there is no phase difference between the communication device and the system, the wireless communication module is directly activated by the rising or falling edge of the square wave. If there is a phase difference, a timer is activated by the rising or falling edge of the square wave, generating a hardware interrupt. After a fixed delay, the wireless communication module is activated.

[0092] After power-on on the control side, based on the AC phase angle or zero-crossing signal, a time synchronization broadcast containing the current time is sent to all terminals at a fixed phase angle time. The broadcast is sent periodically and terminal responses are not accepted. The phase angle broadcast can be sent at the same time interval, and the time interval can be adjusted according to the system's time synchronization accuracy requirements.

[0093] After power-on, the terminal begins zero-crossing detection. Upon reaching the agreed phase angle, a timer starts counting. Simultaneously, it immediately switches to the synchronization frequency to receive the synchronization broadcast. Upon receiving the synchronization signal, it compares it with the timer time, calculates the time deviation, updates the time, and then switches back to the operating frequency after the time update.

[0094] Thus, this disclosure, within a short range, uses a fixed voltage phase angle time point as the wireless transmission and reception start time for each wireless IoT terminal, achieving a time slot allocation error of less than 100µs for all devices in the entire communication system within a 50Hz AC environment. This allows for precise time synchronization in 10ms units via voltage phase angle (zero-crossing) events.

[0095] According to another aspect of the present disclosure, an Internet of Things (IoT) control side is provided, which may include a first phase angle detection module, a first timer, and a first communication module, and the control side is configured to execute the above-described method applied to the IoT control side.

[0096] According to another aspect of the present disclosure, an Internet of Things (IoT) terminal side is provided, which may include a second phase angle detection module, a second timer, and a second communication module. The terminal side is configured to execute the above-described method applied to the IoT terminal side.

[0097] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for wireless communication time synchronization in the power Internet of Things, characterized in that, The method is applied to the control side of an Internet of Things (IoT) and includes: Step 10: When the control side determines that the current time has entered the time synchronization period, if it detects that the current AC voltage phase angle is a preset phase angle, it switches from the working frequency point to the time synchronization frequency point and sends a time synchronization broadcast at the time synchronization frequency point. The time synchronization broadcast is used to synchronize the time between the IoT terminal side and the control side. The IoT terminal side and the control side are located in the same AC power supply area. Step 11: After the time synchronization broadcast is completed, the control side switches from the time synchronization frequency to the working frequency. When there is a phase angle difference between the control side and the power supply, the control side includes a first phase angle detection module, a first timer, and a first communication module. Step 10 further includes: Step 103: When entering the time synchronization period at the current moment, the first phase angle detection module determines the phase angle of the input AC voltage; Step 104: When the first phase angle detection module determines that the phase angle of the input AC voltage is a preset phase angle, it sends a first trigger signal to the first timer. Step 105: When the first timer receives the first trigger signal, it causes a hardware interrupt on the control side until the time delay corresponding to the phase angle difference is reached, and then sends the second trigger signal to the first communication module. Step 106: Upon receiving the second trigger signal, the first communication module switches from the operating frequency to the time synchronization frequency and sends a time synchronization broadcast at the time synchronization frequency.

2. The method according to claim 1, characterized in that, When there is no phase angle difference between the control side and the power supply, the control side includes a first phase angle detection module and a first communication module, and step 10 includes: Step 100: When entering the time synchronization period at the current moment, the first phase angle detection module determines the input AC voltage phase angle; Step 101: If the first phase angle detection module determines that the phase angle of the input AC voltage is a preset phase angle, it sends a first trigger signal to the first communication module. Step 102: Upon receiving the first trigger signal, the first communication module switches from the operating frequency to the time synchronization frequency and sends a time synchronization broadcast at the time synchronization frequency.

3. The method according to claim 1 or 2, characterized in that, The first phase angle detection module is a Fourier transform module, used to perform Fourier transform processing on the input AC voltage to determine the voltage phase angle of the input AC voltage; or The preset phase angle is the zero-crossing phase angle, and the first phase angle detection module is a zero-point detection module used to detect the zero-crossing phase angle of the input AC voltage.

4. A method for wireless communication time synchronization in the power Internet of Things, characterized in that, The method is applied to the IoT terminal side, and the method includes: Step 20: When the terminal enters the time synchronization period at the current moment, if it detects that the terminal has lost time synchronization with the control side, or that the time synchronization duration exceeds the preset duration, the time synchronization mode is activated. Step 21: In time synchronization mode, if the terminal detects that the AC voltage phase angle is the preset phase angle, the timer is started and the operating frequency is switched to the time synchronization frequency. The time synchronization frequency is used to listen for time synchronization broadcasts. Step 22: Upon receiving the time synchronization broadcast, the terminal obtains the timer's duration. Step 23: The terminal side calibrates its time based on the time and timing duration obtained from the time broadcast parsing. Step 24: After the time calibration on the terminal side is completed, switch from the time synchronization frequency point to the working frequency point; When there is a phase angle difference between the terminal side and the power supply, the terminal side includes a second phase angle detection module, a second timer, and a second communication module. Step 21 further includes: Step 213: In time synchronization mode, the second phase angle detection module determines the phase angle of the input AC voltage; Step 214: When the detection module determines that the phase angle of the input AC voltage is a preset phase angle, it sends a first trigger signal to the second timer. Step 215: When the second timer receives the first trigger signal, it causes a hardware interrupt on the terminal side until the time delay corresponding to the phase angle difference is reached, and then sends the second trigger signal to the second communication module. Step 216: Upon receiving the second trigger signal, the second communication module switches from the operating frequency to the time synchronization frequency and listens for time synchronization broadcasts on the time synchronization frequency.

5. The method according to claim 4, characterized in that, When there is no phase angle difference between the terminal side and the power supply, the terminal side includes a second phase angle detection module and a second communication module. Step 21 includes: Step 210: In time synchronization mode, the second phase angle detection module determines the phase angle of the input AC voltage; Step 211: If the second phase angle detection module determines that the phase angle of the input AC voltage is the preset phase angle, it sends a first trigger signal to the second communication module. Step 212: Upon receiving the first trigger signal, the second communication module switches from the operating frequency to the time synchronization frequency and listens for time synchronization broadcasts on the time synchronization frequency.

6. The method according to claim 4 or 5, characterized in that, The second phase angle detection module is a Fourier transform module, used to perform Fourier transform processing on the input AC voltage to determine the voltage phase angle of the input AC voltage; or The preset phase angle is the zero-crossing phase angle, and the second phase angle detection module is a zero-point detection module used to detect the zero-crossing phase angle of the input AC voltage.

7. An Internet of Things (IoT) control-side device, characterized in that, The control-side device includes a first phase angle detection module, a first timer, and a first communication module, and the control-side device is configured to perform the method described in any one of claims 1 to 3.

8. An Internet of Things (IoT) terminal-side device, characterized in that, The terminal-side device includes a second phase angle detection module, a second timer, and a second communication module, and the terminal-side device is configured to perform the method described in any one of claims 4 to 6.

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