Analysis Method of Low Voltage Fault Factors in Distribution Network

Abstract

The present invention provides a method for analyzing factors of low voltage faults in a distribution network, comprising the following steps: S1. determining high voltage, medium voltage and low voltage nodes in the distribution network, and setting a detection unit at the node position to detect the voltage and current of each node; S2. judging whether the voltage of each node is currently lower than a set threshold value, if so, there is low voltage; S3. calculating the active power and reactive power of the node based on the voltage and current of each node, and calculating the power factor, judging whether the power factor is lower than the set threshold value, if so, generating early warning information that the power factor is too low and causes low voltage in the distribution network, if not, entering step S4; S4. using the detection unit to detect the three-phase current and three-phase voltage of the distribution transformer of each node, and calculating the three-phase load of the distribution transformer based on the three-phase current and the three-phase voltage, and judging whether the three-phase load is balanced, if not, generating early warning information that the low voltage is caused by the unbalanced load of the distribution transformer at the current node, if so, generating early warning information of other factors.

Description

Technical Field

[0001] The invention relates to a power fault analysis method, and in particular to a distribution network low voltage fault factor analysis method. Background Art

[0002] The distribution network is a key link in the power system that directly connects with users and provides power to users. When the distribution network is in operation, low voltage problems are often prone to occur. Low voltage problems will cause users' electrical equipment to fail to operate normally, affecting life and production efficiency. In addition, low voltage will lead to increased transmission losses in the distribution network, reducing the economy of power distribution, and reducing the frequency of power supply, affecting the operation of power plants.

[0003] In the prior art, accurate warning cannot be given when a low voltage fault occurs in the distribution network. Manual analysis and troubleshooting are often performed by experienced staff. This method is inefficient and, more importantly, is affected by the staff's supervisory factors, thereby affecting the accuracy of the final warning result.

[0004] Therefore, in order to solve the above technical problems, it is urgent to propose a new technical means. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a method for analyzing low-voltage fault factors in a distribution network. By setting corresponding detection points at high, medium and low voltage nodes in the distribution network, low-voltage fault warnings can be performed in real time and accurately based on the voltage and current information of the detection points, thereby effectively ensuring the accuracy of the warning and facilitating subsequent operation and maintenance processing.

[0006] The present invention provides a method for analyzing low voltage fault factors in a distribution network, comprising the following steps:

[0007] S1. Determine the high voltage, medium voltage and low voltage nodes in the distribution network, and set up detection units at the node locations to detect the voltage and current of each node;

[0008] S2. Determine whether the current voltage of each node is lower than the set threshold. If so, there is low voltage;

[0009] S3. Calculate the active power and reactive power of the node based on the voltage and current of each node, and calculate the power factor to determine whether the power factor is lower than the set threshold. If so, generate a warning message that the power factor is too low to cause low voltage in the distribution network. If not, proceed to step S4;

[0010] S4. Use the detection unit to detect the three-phase current and three-phase voltage of the distribution transformer at each node, and calculate the three-phase load of the distribution transformer based on the three-phase current and three-phase voltage, and determine whether the three-phase load is balanced. If not, generate an early warning message that the low voltage is caused by the unbalanced load of the distribution transformer at the current node. If so, generate early warning information of other factors.

[0011] Further, in step S1 and step S4, the detection unit includes a voltage sensor, a current sensor, a sampling module, a processing module and a wireless transmission module;

[0012] The output ends of the voltage sensor and the current sensor are connected to the input end of the sampling module, and the output end of the sampling module is connected to the processing module. The processing module determines whether a low voltage fault occurs and the fault factor based on the received current and voltage signals, and generates corresponding warning information. The processing module is connected to the remote server through the wireless communication module.

[0013] Furthermore, the processing module includes a processor, a coding circuit and a memory;

[0014] The processor is connected to the encoding circuit, the processor is connected to the output end of the sampling module, the processor is connected to the remote server through the wireless communication module, the processor determines whether a low voltage fault occurs and the fault factor based on the received current and voltage signals, and generates corresponding warning information, and the processor is connected to the memory.

[0015] Furthermore, other factors in step S4 include unreasonable distribution transformer joints, too large a power supply radius of the distribution transformer, and too small a wire diameter of the distribution network conductor.

[0016] Furthermore, the wireless communication module is a 2.4G power wireless private network module or a 5G module.

[0017] Beneficial effects of the present invention: Through the present invention, by setting corresponding detection points at each high, medium and low voltage node of the distribution network, low voltage fault warning is carried out in real time and accurately according to the voltage and current information of the detection points, thereby effectively ensuring the warning accuracy and facilitating subsequent operation and maintenance processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0019] Figure 1 It is a flow chart of the present invention.

[0020] Figure 2 It is a schematic diagram of the structure of the detection unit of the present invention. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below:

[0022] The present invention provides a method for analyzing low voltage fault factors in a distribution network, comprising the following steps:

[0023] S1. Determine the high voltage, medium voltage and low voltage nodes in the distribution network, and set up detection units at the node locations to detect the voltage and current of each node;

[0024] S2. Determine whether the current voltage of each node is lower than the set threshold. If so, there is low voltage;

[0025] S3. Based on the voltage and current of each node, the active power and reactive power of the node are calculated, and the power factor is calculated to determine whether the power factor is lower than the set threshold. If so, an early warning message indicating that the power factor is too low and the distribution network has low voltage is generated. If not, the process proceeds to step S4; wherein the calculation of active power and reactive power are respectively:

[0026] P = UIcosθ, Q = UIsinθ; where P represents active power, Q represents reactive power, U represents voltage, I represents current, θ represents the phase angle of voltage, and power factor is the ratio of active power to reactive power;

[0027] When the distribution network is under voltage due to too low power factor, the compensation value of the active power and / or reactive power of the distribution network is adjusted to overcome the low voltage fault;

[0028] S4. Use the detection unit to detect the three-phase current and three-phase voltage of the distribution transformer at each node, and calculate the three-phase load of the distribution transformer based on the three-phase current and three-phase voltage, and judge whether the three-phase load is balanced. If not, generate early warning information of low voltage caused by unbalanced load of the distribution transformer at the current node. If so, generate early warning information of other factors. When the three-phase load is unbalanced, on the one hand, it indicates that the distribution transformer (referred to as distribution transformer) is unreasonable, and on the other hand, the load is unreasonable, so operation and maintenance are performed. Other factors include unreasonable distribution transformer joints, too large power supply radius of distribution transformer, too small wire diameter of distribution network conductor; of course, it also includes factors such as line aging. Through the above method, by setting corresponding detection points at high, medium and low voltage nodes of the distribution network, low voltage fault early warning is performed in real time and accurately according to the voltage and current information of the detection points, so as to effectively ensure the accuracy of early warning and facilitate subsequent operation and maintenance.

[0029] In this embodiment, in step S1 and step S4, the detection unit includes a voltage sensor, a current sensor, a sampling module, a processing module and a wireless transmission module;

[0030] The output ends of the voltage sensor and the current sensor are connected to the input end of the sampling module, and the output end of the sampling module is connected to the processing module. The processing module determines whether a low voltage fault occurs and the fault factor based on the received current and voltage signals, and generates corresponding warning information. The processing module is connected to the remote server through the wireless communication module.

[0031] Specifically, the processing module includes a processor, a coding circuit and a memory;

[0032] The processor is connected to the encoding circuit, the processor is connected to the output end of the sampling module, the processor is connected to the remote server through the wireless communication module, the processor determines whether a low voltage fault occurs and the fault factor according to the received current and voltage signals, and generates corresponding early warning information, the processor is connected to the memory, wherein the encoding circuit adopts the existing dip switch, the switch provides a coding information to the processor, and the coding information represents the position of the current detection unit in the distribution network, the processor adopts the existing chip, such as AT89C2051 chip, STM32 chip, the memory adopts the existing memory chip and its peripheral circuit, such as 24LC128 chip, the wireless transmission module adopts the existing 2.4G power wireless private network module or 4G module, 5G module, etc.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for analyzing low voltage fault factors in a distribution network, characterized by: The following steps are involved: S1. Determine the high voltage, medium voltage and low voltage nodes in the distribution network, and set up detection units at the node locations to detect the voltage and current of each node; S2. Determine whether the current voltage of each node is lower than the set threshold. If so, there is low voltage; S3. Calculate the active power and reactive power of the node based on the voltage and current of each node, and calculate the power factor to determine whether the power factor is lower than the set threshold. If so, generate a warning message that the power factor is too low to cause low voltage in the distribution network. If not, proceed to step S4; S4. Use the detection unit to detect the three-phase current and three-phase voltage of the distribution transformer at each node, and calculate the three-phase load of the distribution transformer based on the three-phase current and three-phase voltage, and determine whether the three-phase load is balanced. If not, generate an early warning message that the low voltage is caused by the unbalanced load of the distribution transformer at the current node. If so, generate early warning information of other factors.

2. The method for analyzing low voltage fault factors in a distribution network according to claim 1, characterized in that: In step S1 and step S4, the detection unit includes a voltage sensor, a current sensor, a sampling module, a processing module and a wireless transmission module; The output ends of the voltage sensor and the current sensor are connected to the input end of the sampling module, and the output end of the sampling module is connected to the processing module. The processing module determines whether a low voltage fault occurs and the fault factor based on the received current and voltage signals, and generates corresponding warning information. The processing module is connected to the remote server through the wireless communication module.

3. The method for analyzing low voltage fault factors in a distribution network according to claim 2, characterized in that: The processing module includes a processor, a coding circuit and a memory; The processor is connected to the encoding circuit, the processor is connected to the output end of the sampling module, the processor is connected to the remote server through the wireless communication module, the processor determines whether a low voltage fault occurs and the fault factor based on the received current and voltage signals, and generates corresponding warning information, and the processor is connected to the memory.

4. The method for analyzing low voltage fault factors in a distribution network according to claim 1, characterized in that: Other factors in step S4 include unreasonable distribution transformer joints, too large a power supply radius of the distribution transformer, and too small a wire diameter of the distribution network conductor.

5. The method for analyzing low voltage fault factors in a distribution network according to claim 3 is characterized in that: The wireless communication module is a 2.4G power wireless private network module or a 5G module.

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