AC power transmission direction detection system and method

Abstract

The invention discloses an alternating current power transmission direction detection system and method. The alternating current power transmission direction detection system comprises a voltage phase detection circuit, a current phase detection circuit and a phase comparison output circuit, the input end of the voltage phase detection circuit is electrically connected with the output end of an alternating current power supply, and the output end of the voltage phase detection circuit is electrically connected with the first input end of the phase comparison output circuit; the input end of the current phase detection circuit is electrically connected with the output end of the alternating current power supply, and the output end of the current phase detection circuit is electrically connected with the second input end of the phase comparison output circuit; and the phase comparison output circuit is used for receiving the voltage phase signal detected by the voltage phase detection circuit and the current phase signal detected by the current phase detection circuit, and determining and outputting a power transmission direction signal based on the voltage phase signal and the current phase signal.

Description

Technical Field

[0001] The present application relates to the technical field of power grid monitoring, and in particular to an AC power transmission direction detection system and method. Background Art

[0002] With the rapid development of smart grids and distributed energy systems, the bidirectional flow of electricity has become one of the important directions in power system research. Especially in the application scenario where a self-generated system is connected to the grid, how to effectively monitor and control the transmission direction of electric energy has become a key issue to ensure the stability and safe operation of the grid. Specifically, when a self-generated system is connected to the grid, in order to avoid unnecessary fluctuations or impacts of self-generated electricity on the grid, it becomes crucial to detect and control the power transmission direction in real time.

[0003] In the prior art, many high-performance energy meters have the function of detecting the power transmission direction. These energy meters can output the parameters of the power transmission direction to help users understand the direction of the power flow. However, these energy meters usually have the following problems: First, the price is relatively high, which is not conducive to popularization in the low-end and mid-end markets; second, the power direction signal is only for viewing, lacks output function, cannot be linked with power converters and other equipment, and cannot achieve real-time control of the power transmission direction; third, some energy meters have a slow response speed, which makes it difficult to meet the needs of fast and precise control.

[0004] Therefore, there is an urgent need for an AC power transmission direction detection system and method to solve the problems of inaccurate power direction detection, insufficient signal output and excessively high cost in the prior art. Summary of the invention

[0005] The present application provides an AC power transmission direction detection system and method, aiming to solve the problems of inaccurate power direction detection, insufficient signal output and excessively high cost in the prior art.

[0006] In a first aspect, an AC power transmission direction detection system includes a voltage phase detection circuit and a current phase detection circuit, and a phase comparison output circuit;

[0007] The input end of the voltage phase detection circuit is electrically connected to the output end of the AC power supply, and the output end of the voltage phase detection circuit is electrically connected to the first input end of the phase comparison output circuit; the voltage phase detection circuit is used to detect the voltage phase signal of the AC power supply, and output the detected voltage phase signal to the phase comparison output circuit;

[0008] The input end of the current phase detection circuit is electrically connected to the output end of the AC power supply, and the output end of the current phase detection circuit is electrically connected to the second input end of the phase comparison output circuit; the current phase detection circuit is used to detect the current phase signal of the AC power supply, and output the detected current phase signal to the phase comparison output circuit;

[0009] The phase comparison output circuit is used to receive the voltage phase signal and the current phase signal, and determine and output a power transmission direction signal based on the voltage phase signal and the current phase signal.

[0010] In the above solution, optionally, the voltage phase detection circuit includes a voltage divider circuit, a power supply circuit and a first comparator;

[0011] The input end of the voltage divider circuit is electrically connected to the output end of the AC power supply, the output end of the voltage divider circuit is electrically connected to the non-phase input end of the first comparator, the output end of the power supply circuit is electrically connected to the inverting input end of the first comparator, and the output end of the first comparator is electrically connected to the first input end of the phase comparison output circuit.

[0012] In the above solution, further optionally, the voltage divider circuit includes a first resistor R1 and a second resistor R2;

[0013] One end of the first resistor R1 is electrically connected to the live line output end of the AC power supply, one end of the second resistor R2 is electrically connected to the neutral line output end of the AC power supply, and the other end of the first resistor R1 is electrically connected to the other end of the second resistor R2;

[0014] A connection terminal of the first resistor R1 and the second resistor R2 is electrically connected to a non-inverting input terminal of the first comparator.

[0015] In the above solution, further optionally, the power supply circuit includes a fourth resistor R4 and a fifth resistor R5;

[0016] One end of the fourth resistor R4 is used to connect to the power supply voltage VCC, the other end of the fourth resistor R4 is connected to one end of the fifth resistor R5, and the other end of the fifth resistor R5 is grounded;

[0017] A connection terminal of the fourth resistor R4 and the fifth resistor R5 is electrically connected to an inverting input terminal of the first comparator.

[0018] In the above solution, further optionally, the current phase detection circuit includes a current transformer L1 and a second comparator;

[0019] The input end of the current transformer L1 is electrically connected to the output end of the AC power supply, the output end of the current transformer L1 is electrically connected to the non-phase input end of the second comparator, the inverting input end of the second comparator is grounded, and the output end of the second comparator is electrically connected to the second input end of the phase comparison output circuit.

[0020] In the above scheme, further optionally, the input end of the current transformer L1 is electrically connected to the live wire output end of the AC power supply, the first output end of the current transformer L1 is grounded, and the second output end of the current transformer L1 is respectively connected to one end of the third resistor R3 and the non-phase input end of the second comparator;

[0021] The other end of the third resistor R3 is grounded.

[0022] In the above scheme, further optionally, the phase comparison output circuit includes an XOR gate circuit;

[0023] The first input end of the XOR gate circuit is electrically connected to the output end of the first comparator, the second input end of the XOR gate circuit is electrically connected to the output end of the second comparator, and the output end of the XOR gate circuit is used to output a power transmission direction signal.

[0024] In the above solution, further optionally, when the voltage phase signal and the current phase signal are in phase, the power transmission direction is forward;

[0025] When the voltage phase signal and the current phase signal are in anti-phase, the power transmission direction is reverse.

[0026] In a second aspect, a method for detecting an AC power transmission direction is provided, the method comprising:

[0027] Detecting a voltage phase signal of an AC power supply by a voltage phase detection circuit, and outputting the voltage phase signal to a phase comparison output circuit;

[0028] Detecting a current phase signal of the AC power supply by a current phase detection circuit, and outputting the current phase signal to the phase comparison output circuit;

[0029] The voltage phase signal and the current phase signal are received by the phase comparison output circuit, and a power transmission direction signal is determined and output based on the voltage phase signal and the current phase signal.

[0030] In the above solution, optionally, when the voltage phase signal and the current phase signal are in phase, the power transmission direction is forward;

[0031] When the voltage phase signal and the current phase signal are in anti-phase, the power transmission direction is reverse.

[0032] Compared with the prior art, this application has at least the following beneficial effects:

[0033] Based on further analysis and research of the existing technical problems, this application recognizes that there are problems in the existing technology such as inaccurate power direction detection, insufficient signal output and excessive cost. Through the combination of voltage phase detection circuit, current phase detection circuit and phase comparison output circuit, accurate detection and real-time control of the power transmission direction of AC power supply are realized. Compared with the expensive and slow-responding electric energy meter in the prior art, this system adopts a simple and low-cost circuit design, which can quickly and accurately determine the power transmission direction by detecting the phase difference between voltage and current, and output the corresponding power direction signal. This signal can be linked with other devices such as power converters to support the control of power transmission direction, overcoming the limitation that traditional systems can only view power direction parameters but cannot achieve control. Through this system, the insufficiency of power direction control when the self-generating system is connected to the power grid can be effectively avoided, ensuring that electric energy will not be transmitted to the power grid in reverse, thereby avoiding the occurrence of power grid fluctuations and instability. Because the circuit used by the system is simple and has a fast response speed, it can provide real-time and accurate power transmission direction judgment, meeting the stability and control requirements of the power grid. In general, the present invention significantly reduces costs, improves detection accuracy and response speed, and can solve the problems of high cost, low response and insufficient control in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A circuit principle block diagram of an AC power transmission direction detection system provided in an embodiment of the present application;

[0035] Figure 2 A circuit schematic diagram of an AC power transmission direction detection system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0037] In the description of this application: unless otherwise specified, the meaning of "plurality" is two or more. The terms "first", "second", "third", etc. in this application are intended to distinguish the objects referred to, and do not have special meanings in terms of technical connotations (for example, they should not be understood as emphasizing the importance or order, etc.). Expressions such as "including", "comprising", "having", etc. also mean "not limited to" (certain units, components, materials, steps, etc.).

[0038] like Figure 1 As shown, an embodiment of the present application provides an AC power transmission direction detection system, including a voltage phase detection circuit, a current phase detection circuit, and a phase comparison output circuit.

[0039] The input end of the voltage phase detection circuit is electrically connected to the output end of the AC power supply, and the output end of the voltage phase detection circuit is electrically connected to the first input end of the phase comparison output circuit; the voltage phase detection circuit is used to detect the voltage phase signal of the AC power supply and output the detected voltage phase signal to the phase comparison output circuit.

[0040] The input end of the current phase detection circuit is electrically connected to the output end of the AC power supply, and the output end of the current phase detection circuit is electrically connected to the second input end of the phase comparison output circuit; the current phase detection circuit is used to detect the current phase signal of the AC power supply and output the detected current phase signal to the phase comparison output circuit.

[0041] The phase comparison output circuit is used to receive the voltage phase signal and the current phase signal, and determine and output a power transmission direction signal based on the voltage phase signal and the current phase signal.

[0042] It should be noted that when the voltage phase of the AC power supply and the current phase of the AC power supply are the same, the power transmission direction is forward; when the voltage phase of the AC power supply and the current phase of the AC power supply are opposite, the power transmission direction is reverse.

[0043] The implementation method of the AC power transmission direction detection system proposed in the present invention mainly includes a voltage phase detection circuit, a current phase detection circuit and a phase comparison output circuit. The working principle of the system is based on the detection and comparison of the voltage and current phase signals of the AC power supply, so as to accurately determine the power transmission direction.

[0044] The voltage phase detection circuit processes the voltage signal of the AC power supply through a voltage divider circuit. Specifically, the voltage phase detection circuit includes a voltage divider circuit composed of two groups of resistors (such as a first resistor R1 and a second resistor R2). The voltage divider circuit divides the voltage signal of the AC power supply to an appropriate range (such as 5V), and then compares it with a reference voltage through a comparator (such as a first comparator) to output a voltage phase signal.

[0045] When the voltage signal is positive, the output of the comparator is high level; when the voltage signal is negative, the output of the comparator is low level. The voltage phase signal is transmitted to the first input terminal of the phase comparison output circuit through the circuit for subsequent phase comparison.

[0046] The current phase detection circuit is mainly composed of a current transformer L1 and a second comparator. The current transformer L1 is used to detect the current signal flowing through the AC power supply. The direction and magnitude of the current signal will affect the direction of power transmission. The output signal of the current transformer is processed by a limiting circuit (such as the third resistor R3) and then input to the second comparator.

[0047] The working principle of the second comparator is similar to that of the first comparator in the voltage phase detection circuit. The comparator determines the direction of the current signal. If the current signal is positive, the comparator outputs a high level; if the current signal is reverse, it outputs a low level. The current phase signal is output to the second input terminal of the phase comparison output circuit, which is further used to determine the power transmission direction.

[0048] The core of the phase comparison output circuit is the XOR gate circuit. The XOR gate makes a logical judgment based on the relative relationship between the voltage phase signal and the current phase signal, and finally outputs a power transmission direction signal. Specifically, if the voltage phase signal is consistent with the current phase signal (that is, both are high or low), the power transmission direction is forward and the output is low; if the voltage phase signal and the current phase signal are opposite (that is, one is high and the other is low), the power transmission direction is reverse and the output is high.

[0049] In this way, the phase comparison output circuit can determine the direction of power transmission in real time and output the corresponding power direction signal. This signal can be further linked with power converters and other devices to optimize the power flow, thereby achieving precise power transmission direction control.

[0050] In this embodiment, the traditional electric energy meter has the function of detecting the power transmission direction, but it is often expensive. The system proposed by the present invention adopts common and low-cost electronic components such as voltage divider circuit, comparator and XOR gate circuit through simple circuit design, avoiding the complex functional modules and high cost in high-performance electric energy meters. The system can not only realize the power transmission direction detection function, but also has the advantages of low cost and simple implementation, and is suitable for wide application in the mid- and low-end markets.

[0051] In addition, the detection signal of the power transmission direction in the existing electric energy meter is usually only used for viewing, and the response speed is slow, which cannot meet the needs of real-time control. The system of the present invention adopts a cycle-by-cycle judgment method, detects the phase signals of voltage and current in real time, and uses a logic circuit for real-time output. This makes the detection of the power transmission direction more accurate and can timely feedback the changes in power transmission, thereby meeting the requirements of fast response. The phase comparison output circuit ensures the system's rapid response capability when the power grid fluctuates or the power transmission is reversed by comparing the voltage and current phase signals in real time.

[0052] The system of the present invention has a low failure rate and high stability through a simple and reliable circuit design. The components such as the voltage divider circuit, comparator and XOR gate circuit in the circuit have clear working principles and stable performance, which can effectively reduce the risk of circuit failure. In addition, the system adopts a cycle-by-cycle judgment method, which can continuously monitor the power transmission direction and is not easily affected by external noise and interference, thereby ensuring the long-term stable operation of the system.

[0053] In the embodiment of the present application, accurate detection and real-time control of the power transmission direction of the AC power supply are achieved by combining the voltage phase detection circuit, the current phase detection circuit and the phase comparison output circuit. Compared with the expensive and slow-responding electric energy meter in the prior art, the system adopts a simple and low-cost circuit design, which can quickly and accurately determine the power transmission direction by detecting the phase difference between voltage and current, and output the corresponding power direction signal. The signal can be linked with other devices such as power converters to support the control of the power transmission direction, overcoming the limitation that the traditional system can only view the power direction parameters but cannot achieve control. Through this system, the insufficiency of power direction control when the self-generating system is connected to the power grid can be effectively avoided, ensuring that the electric energy will not be transmitted to the power grid in reverse, thereby avoiding the occurrence of power grid fluctuations and instability. Since the circuit adopted by the system is simple and the response speed is fast, it can provide real-time and accurate power transmission direction judgment, meeting the stability and control requirements of the power grid. Overall, the present invention significantly reduces the cost, improves the detection accuracy and response speed, and can solve the problems of high cost, low response and insufficient control in the prior art.

[0054] like Figure 2 As shown, in a possible implementation, the voltage phase detection circuit includes a voltage divider circuit, a power supply circuit and a first comparator; the input end of the voltage divider circuit is electrically connected to the output end of the AC power supply, the output end of the voltage divider circuit is electrically connected to the non-phase input end of the first comparator, the output end of the power supply circuit is electrically connected to the inverting input end of the first comparator, and the output end of the first comparator is electrically connected to the first input end of the phase comparison output circuit.

[0055] It should be noted that the voltage signal of the AC power supply comes from the live wire (AC220V-L) and the neutral wire (AC220V-N) of the AC power supply.

[0056] In this embodiment, the voltage phase signal can be accurately collected and processed through the voltage divider circuit, the power supply circuit and the first comparator in the voltage phase detection circuit. The voltage divider circuit reduces the AC voltage signal to a voltage range suitable for processing, ensuring that the first comparator can correctly compare the voltage signal with the reference voltage, thereby improving the measurement accuracy of the system. The design of the power supply circuit can ensure the stable operation of the first comparator and ensure that the output signal is accurate. Through this design, the voltage phase detection circuit can achieve efficient voltage signal processing in a low-cost, low-power manner, improve the system response speed and reliability, and solve the application limitations caused by the high cost and low response speed of the electric energy meter in the background technology.

[0057] like Figure 2 As shown, in a possible implementation, the voltage divider circuit includes a first resistor R1 and a second resistor R2; one end of the first resistor R1 is electrically connected to the live wire output end of the AC power supply, one end of the second resistor R2 is electrically connected to the neutral wire output end of the AC power supply, and the other end of the first resistor R1 is electrically connected to the other end of the second resistor R2; the connection end of the first resistor R1 and the second resistor R2 is electrically connected to the non-inverting input end of the first comparator.

[0058] The voltage divider circuit is composed of a first resistor R1 and a second resistor R2, which divides the AC220V voltage of the AC power supply into a suitable range, usually plus or minus 5V, which is convenient for subsequent processing.

[0059] The first resistor R1 is connected to the live wire end, the second resistor R2 is connected to the neutral wire end, and their connection point is connected to the positive input end of the first comparator U2B (pin 5 of the first comparator U2B). That is, the voltage signal is input to the positive input end of the first comparator U2B.

[0060] The first comparator U2B determines the level state of its output terminal according to the positive and negative changes of the voltage signal. When the first comparator U2B outputs a high level, it indicates that the voltage signal is positive and the phase is positive; when the first comparator U2B outputs a low level, it indicates that the voltage signal is reverse and the phase is negative.

[0061] In this embodiment, by adopting the voltage divider circuit design of the first resistor R1 and the second resistor R2, the system can achieve appropriate voltage division of the voltage signal in a simple and low-cost manner, ensuring that the voltage signal input to the comparator is within a suitable voltage range. This design optimizes the processing process of the voltage signal and improves the accuracy and stability of the system. At the same time, the voltage divider circuit has a simple structure and low cost, which can effectively reduce the manufacturing cost of the entire system, so that it can be widely used in the mid- and low-end markets, solving the problem of the high price of existing electric energy meters.

[0062] like Figure 2As shown, in a possible implementation, the power supply circuit includes a fourth resistor R4 and a fifth resistor R5; one end of the fourth resistor R4 is used to access the power supply voltage VCC, the other end of the fourth resistor R4 is connected to one end of the fifth resistor R5, and the other end of the fifth resistor R5 is grounded; the connection end of the fourth resistor R4 and the fifth resistor R5 is electrically connected to the inverting input end of the first comparator.

[0063] It should be noted that the power supply circuit provides the necessary operating voltage for the circuit. The power supply circuit is connected to the inverting input terminal of the first comparator U2B through the fourth resistor R4 and the fifth resistor R5.

[0064] In addition, the power supply circuit also includes a GND connection to complete the ground loop.

[0065] In this embodiment, the normal operation of the first comparator is ensured by designing a power supply circuit, including a fourth resistor R4 and a fifth resistor R5. The power supply circuit has high stability and can provide a stable reference voltage for the comparator, thereby ensuring that the comparison process of the voltage signal is not affected by external fluctuations. This design makes the output of the voltage phase detection circuit more reliable, thereby improving the accuracy and response speed of the power transmission direction detection system, and effectively avoiding the problem of slow response of the electric energy meter in the background technology.

[0066] like Figure 2 As shown, in a possible implementation, the current phase detection circuit includes a current transformer L1 and a second comparator; the input end of the current transformer L1 is electrically connected to the output end of the AC power supply, the output end of the current transformer L1 is electrically connected to the non-phase input end of the second comparator, the inverting input end of the second comparator is grounded, and the output end of the second comparator is electrically connected to the second input end of the phase comparison output circuit.

[0067] In this embodiment, the current phase detection circuit uses a combination of a current transformer L1 and a second comparator, which can accurately detect the current phase signal of the AC power supply. The current transformer L1 has excellent performance in a low voltage and high current environment and can provide a stable current signal output. The second comparator compares and processes the current signal to ensure that the current phase signal can accurately reflect the change in current, thereby providing high-precision data for determining the direction of power transmission. This design improves the accuracy of current phase detection and ensures that the system can achieve efficient and accurate detection at a lower cost.

[0068] like Figure 2As shown, in a possible implementation, the input end of the current transformer L1 is electrically connected to the live wire output end of the AC power supply, the first output end of the current transformer L1 is grounded, and the second output end of the current transformer L1 is respectively connected to one end of the third resistor R3 and the non-phase input end of the second comparator; the other end of the third resistor R3 is grounded.

[0069] It should be noted that the current signal is sensed by the current transformer L1, and the input end of the current transformer is connected to the AC current signal. The current is limited by the third resistor R3 to ensure that the amplitude of the current signal is suitable for input to the comparator for processing.

[0070] The limited current signal is input to the non-inverting input terminal (pin 2) of the second comparator U2A and compared with the inverting input terminal (pin 3) of the second comparator U2A.

[0071] The output of the second comparator U2A determines the direction of the current signal; when the current flows in the forward direction, the second comparator U2A outputs a high level; when the current flows in the reverse direction, the second comparator U2A outputs a low level.

[0072] In this embodiment, the input end of the current transformer L1 is connected to the live wire output end of the AC power supply, and the output signal is limited by the third resistor R3 to ensure that the current signal is input to the second comparator within an appropriate range. This design not only optimizes the processing flow of the current signal, but also further improves the accuracy and reliability of the system. After the current signal is accurately limited, it can more effectively prevent misjudgment caused by excessively strong or weak signals, ensuring that the judgment of the power transmission direction is more accurate, thereby solving the problem of improper current signal processing in the background technology.

[0073] like Figure 2 As shown, in a possible implementation, the phase comparison output circuit includes an XOR gate circuit; a first input terminal of the XOR gate circuit is electrically connected to the output terminal of the first comparator, a second input terminal of the XOR gate circuit is electrically connected to the output terminal of the second comparator, and an output terminal of the XOR gate circuit is used to output a power transmission direction signal.

[0074] It should be noted that the outputs of the second comparator U2A and the first comparator U2B are the phase information of the current signal and the phase information of the voltage signal, respectively. The phase information of the current signal and the phase information of the voltage signal are input to the two input terminals of the XOR gate U1A.

[0075] When the phases of the voltage signal and the current signal are consistent (i.e., both are forward or both are reverse), the XOR gate outputs a low level, indicating that the power transfer is forward.

[0076] When the phases of the voltage and current signals are inconsistent (i.e., the voltage signal is positive and the current signal is negative, or the voltage signal is negative and the current signal is positive), the XOR gate outputs a high level, indicating that the power transmission is reverse.

[0077] In this embodiment, in the phase comparison output circuit, an XOR gate circuit is used to compare the voltage phase and current phase signals. This design can quickly and effectively determine the power transmission direction, and convert the phase difference between the voltage and current into a power transmission direction signal through the XOR gate circuit. Compared with the traditional method, the XOR gate circuit has a simple structure and a fast response speed, which can ensure that the system outputs the power transmission direction signal in real time when the voltage and current signals change, thereby overcoming the problems of insufficient detection accuracy and response delay of the existing electric energy meter.

[0078] like Figure 2 As shown, in a possible implementation manner, when the voltage phase signal and the current phase signal are in phase, the power transmission direction is forward; when the voltage phase signal and the current phase signal are in anti-phase, the power transmission direction is reverse.

[0079] In this embodiment, by setting the voltage phase signal and the current phase signal to the same state, the system can determine that the power transmission direction is forward. This design enables the system to intuitively determine and output the state of forward power transmission, simplifying the power direction control process. In practical applications, it can help users easily determine the direction of electric energy flow, ensure stable and reliable power transmission between the power grid and the self-generation system, avoid unnecessary reverse power transmission, and thus protect the safety of power grid equipment and systems.

[0080] The present application also provides a method for detecting an AC power transmission direction, the method comprising the following steps:

[0081] Detecting a voltage phase signal of an AC power supply by a voltage phase detection circuit, and outputting the voltage phase signal to a phase comparison output circuit;

[0082] Detecting a current phase signal of the AC power supply by a current phase detection circuit, and outputting the current phase signal to the phase comparison output circuit;

[0083] The voltage phase signal and the current phase signal are received by the phase comparison output circuit, and a power transmission direction signal is determined and output based on the voltage phase signal and the current phase signal.

[0084] In this embodiment, when the states of the voltage phase signal and the current phase signal are opposite, the system determines that the power transmission direction is reverse. This judgment mechanism can monitor the changes in the power transmission direction in real time, ensuring that when the electric energy is transmitted in the reverse direction, the system can respond in time and take corresponding control measures to prevent the electric energy from flowing back to the power grid, thereby avoiding fluctuations or damage to the power grid. This design effectively enhances the safety and stability of the power system and meets the demand for precise control of the power transmission direction in the background technology.

[0085] In a possible implementation manner, when the voltage phase signal and the current phase signal are in phase, the power transmission direction is forward; and when the voltage phase signal and the current phase signal are in anti-phase, the power transmission direction is reverse.

[0086] In this embodiment, the present invention can realize accurate adjustment and real-time control of the power transmission direction by linking the output power transmission direction signal with the power converter. This design enables the power converter to automatically adjust the power conversion mode according to the detected power transmission direction signal, thereby optimizing the transmission and use of electric energy and avoiding grid load fluctuations and instability. This linkage control mechanism improves the automation and intelligence level of the entire power system, and provides effective support for the stable operation of smart grids and self-generation systems.

[0087] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. An AC power transmission direction detection system, characterized in that: The system includes a voltage phase detection circuit and a current phase detection circuit, and a phase comparison output circuit; The input end of the voltage phase detection circuit is electrically connected to the output end of the AC power supply, and the output end of the voltage phase detection circuit is electrically connected to the first input end of the phase comparison output circuit; the voltage phase detection circuit is used to detect the voltage phase signal of the AC power supply, and output the detected voltage phase signal to the phase comparison output circuit; The input end of the current phase detection circuit is electrically connected to the output end of the AC power supply, and the output end of the current phase detection circuit is electrically connected to the second input end of the phase comparison output circuit; the current phase detection circuit is used to detect the current phase signal of the AC power supply, and output the detected current phase signal to the phase comparison output circuit; The phase comparison output circuit is used to receive the voltage phase signal and the current phase signal, and determine and output a power transmission direction signal based on the voltage phase signal and the current phase signal.

2. The system according to claim 1, characterized in that The voltage phase detection circuit includes a voltage dividing circuit, a power supply circuit and a first comparator; The input end of the voltage divider circuit is electrically connected to the output end of the AC power supply, the output end of the voltage divider circuit is electrically connected to the non-phase input end of the first comparator, the output end of the power supply circuit is electrically connected to the inverting input end of the first comparator, and the output end of the first comparator is electrically connected to the first input end of the phase comparison output circuit.

3. The system according to claim 2, characterized in that The voltage divider circuit includes a first resistor R1 and a second resistor R2; One end of the first resistor R1 is electrically connected to the live line output end of the AC power supply, one end of the second resistor R2 is electrically connected to the neutral line output end of the AC power supply, and the other end of the first resistor R1 is electrically connected to the other end of the second resistor R2; A connection terminal of the first resistor R1 and the second resistor R2 is electrically connected to a non-inverting input terminal of the first comparator.

4. The system according to claim 2, characterized in that The power supply circuit includes a fourth resistor R4 and a fifth resistor R5; One end of the fourth resistor R4 is used to connect to the power supply voltage VCC, the other end of the fourth resistor R4 is connected to one end of the fifth resistor R5, and the other end of the fifth resistor R5 is grounded; A connection terminal of the fourth resistor R4 and the fifth resistor R5 is electrically connected to an inverting input terminal of the first comparator.

5. The system according to claim 2, characterized in that The current phase detection circuit includes a current transformer L1 and a second comparator; The input end of the current transformer L1 is electrically connected to the output end of the AC power supply, the output end of the current transformer L1 is electrically connected to the non-phase input end of the second comparator, the inverting input end of the second comparator is grounded, and the output end of the second comparator is electrically connected to the second input end of the phase comparison output circuit.

6. The system according to claim 5, characterized in that The input end of the current transformer L1 is electrically connected to the live wire output end of the AC power supply, the first output end of the current transformer L1 is grounded, and the second output end of the current transformer L1 is respectively connected to one end of the third resistor R3 and the non-phase input end of the second comparator; The other end of the third resistor R3 is grounded.

7. The system according to claim 5, characterized in that The phase comparison output circuit includes an XOR gate circuit; The first input end of the XOR gate circuit is electrically connected to the output end of the first comparator, the second input end of the XOR gate circuit is electrically connected to the output end of the second comparator, and the output end of the XOR gate circuit is used to output a power transmission direction signal.

8. The system according to claim 1, characterized in that When the voltage phase signal and the current phase signal are in phase, the power transmission direction is forward; When the voltage phase signal and the current phase signal are in anti-phase, the power transmission direction is reverse.

9. A method for detecting AC power transmission direction, using the AC power transmission direction detection system according to any one of claims 1 to 8, characterized in that: The method comprises: Detecting a voltage phase signal of an AC power supply by a voltage phase detection circuit, and outputting the voltage phase signal to a phase comparison output circuit; Detecting a current phase signal of the AC power supply by a current phase detection circuit, and outputting the current phase signal to the phase comparison output circuit; The voltage phase signal and the current phase signal are received by the phase comparison output circuit, and a power transmission direction signal is determined and output based on the voltage phase signal and the current phase signal.

10. The system according to claim 7, characterized in that When the voltage phase signal and the current phase signal are in phase, the power transmission direction is forward; When the voltage phase signal and the current phase signal are in anti-phase, the power transmission direction is reverse.

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