High-voltage pulse type signal acquisition unit

Abstract

The utility model relates to the technical field of signal acquisition units, and discloses a high-voltage pulse type signal acquisition unit, which comprises a pulse selection unit, a current acquisition circuit and a central processing unit, the program process comprises the steps of device power-on, parameter initialization, task allocation, zero sequence circuit task, communication and others, and data transmission. When the device collects a direct current power supply of about 24V, the device is powered on and initialized to start, in the first step, a current signal is reduced through a current transformer, and then rectification and voltage stabilization are carried out through a diode; the triode amplifies the signal; the resistor carries out voltage division and current division; the capacitor performs filtering coupling; and then the signal is transmitted to a single chip microcomputer on the pulse selection unit, and then the data is transmitted to a host through CAN communication by a current algorithm program burnt in an MCU.

Description

Technical Field

[0001] The utility model relates to the technical field of signal acquisition units, in particular to a high-voltage pulse signal acquisition unit. Background Art

[0002] my country's distribution networks mostly utilize 3-35 kV neutral-point non-effectively grounded systems. According to incomplete statistics, single-phase ground faults and related faults account for over 80% of distribution network operational failures. In recent years, with the rapid development of urbanization, the proportion of cable lines has also gradually increased, and the capacitive current at the fault site has become increasingly large. Therefore, arc suppression coils are added to form a resonant grounding system (NES) to compensate for and limit the capacitive current entering the ground. Resonant grounding systems (NES) are increasingly being used in urban distribution network construction. However, due to the compensation effect of arc suppression coils, when a permanent single-phase ground fault occurs in the resonant grounding system, the signal characteristics of the faulty line and the non-faulty line are unclear, making it difficult to accurately identify the faulty line in a timely manner, leading to the escalation of the incident. Therefore, to ensure the stable and safe operation of the distribution network, research on line selection methods for resonant grounding systems is necessary. Improving the accuracy of line selection is essential for ensuring stable and safe distribution network operation.

[0003] The solution currently proposed on the market for this situation is a small current grounding line selection device. However, the current small current grounding line selection device directly collects continuous current to determine whether there is a ground fault in the circuit. The directly collected current signal is extremely susceptible to interference, resulting in low measurement accuracy.

[0004] How to improve the measurement accuracy of line selection is the key to solving this problem. Through numerous materials and technical exchanges on ground faults, we found that pulse units can greatly improve the accuracy of line selection. Utility Model Content

[0005] In order to solve the technical problem that the existing small current grounding line selection device directly collects continuous current to determine whether a ground fault occurs in the circuit, and the directly collected current signal is easily interfered with, resulting in low measurement accuracy, the utility model provides a high-voltage pulse signal acquisition unit.

[0006] The utility model adopts the following technical solutions to realize: a high-voltage pulse signal acquisition unit, comprising: a pulse selection unit, a current acquisition circuit and a central processing unit;

[0007] Wherein, the pulse selection unit is electrically connected to the current sampling circuit, the current sampling circuit is electrically connected to the current analysis circuit, and the current analysis circuit is electrically connected to the central processing unit;

[0008] The current acquisition circuit is electrically connected to the MCU main circuit, and the MCU main circuit is electrically connected to the communication circuit;

[0009] Secondly, the current acquisition circuit includes a current sampling loop and a current analysis loop, which are mainly used to measure and monitor the current size in the circuit and analyze the current size.

[0010] Preferably, the MCU main circuit is electrically connected to a power conversion, and the MCU main circuit includes a program flow.

[0011] Preferably, the program flow includes the following steps:

[0012] S1. Power on the device;

[0013] S2, parameter initialization;

[0014] S3, task allocation;

[0015] S4, zero sequence circuit tasks, communications and others;

[0016] S5. Data transmission.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] When the utility model is in use, an independent chip is provided inside each KC200-10 pulse selection unit, so that the operation rate is greatly improved, and the pulse line selection method is adopted to improve the reliability of the monitoring system operation and diagnosis.

[0019] When in use, the utility model adopts an intelligent grounding signal extraction device to fully ensure the accuracy and linearity of monitoring, adopts an industrial-grade microcontroller to quickly determine the cause and location of the fault in terms of processing speed, and improves the speed of handling accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the overall structure of the product of the utility model;

[0021] Figure 2 This is a product program flow chart of the utility model;

[0022] Figure 3 This is the product hardware structure diagram of this utility model. DETAILED DESCRIPTION

[0023] Current line selection equipment is generally divided into two major parts: hardware and software. The hardware circuit includes an intelligent grounding signal extraction part, a pre-processing circuit part, a digital waveform acquisition device, and an on-site communication control circuit. It can realize multiple functions such as signal conversion, amplification, filtering, triggering, and sampling, and mainly completes functions such as data signal acquisition, program-controlled amplification, and filtering. The software part uses analytical methods such as FFT based on the established mathematical model to calculate physical quantities such as dielectric loss, partial discharge, frequency, capacitance, and leakage current, and stores them in a database as a criterion for analyzing the possibility of faults. The online monitoring system generally consists of an intelligent grounding signal extraction system, a signal acquisition system, and an analysis and diagnosis system.

[0024] Signal acquisition system: mainly used for signal sampling and transmission, composed of various sensors and signal transmission cables. The sensors are mainly used to realize the acquisition of pulse signals and isolation from primary operating equipment, and the required transmission signals are transmitted to the signal processing part;

[0025] Intelligent ground signal extraction system: It mainly performs the first step of analysis and processing on the sampling signal and transmits it to the microprocessor, enhances the transient pulse signal obtained by the sensor and transmits it to the host, which then performs a second analysis on the signal, thereby enhancing the anti-interference ability and improving the measurement accuracy.

[0026] Below, the present invention is further described in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0027] Example 1: Please refer to Figure 1 - Figure 3 , a high-voltage pulse signal acquisition unit of this embodiment includes: a pulse selection unit, a current acquisition circuit and a central processing unit;

[0028] The current acquisition circuit includes a current sampling circuit and a current analysis circuit, which are mainly used to measure and monitor the current in the circuit and analyze the current;

[0029] The pulse selection unit is electrically connected to the current sampling circuit, the current sampling circuit is electrically connected to the current analysis circuit, the current analysis circuit is electrically connected to the central processing unit, the current acquisition circuit is electrically connected to the MCU main circuit, and the MCU main circuit is electrically connected to the communication circuit;

[0030] The host part includes a central processing unit, a three-phase voltage acquisition circuit, a data display device, a key control circuit and an alarm control circuit;

[0031] Thus, the MCU of the pulse selection unit device sends the current signal collected by the current sampling circuit to the host through the CAN communication circuit;

[0032] The current acquisition circuit reduces the current signal through a current transformer, and then passes it through: a. diodes for rectification and voltage stabilization; b. transistors for signal amplification; c. resistors for voltage division and current shunting; d. capacitors for filtering and coupling; and finally transmits the signal to the MCU on the pulse selection unit.

[0033] The communication circuit sends data to the host through the TJA1050 chip according to the format of the CAN communication protocol written in the MCU;

[0034] Furthermore, the MCU main circuit is electrically connected to a power conversion, and the MCU main circuit includes a program flow;

[0035] The power conversion process reduces the 24V DC voltage to 5V by passing it through a linear regulator (LDO). The power isolation module then isolates the power supply and provides the startup voltage to the MCU.

[0036] Secondly, the MCU main circuit analyzes the collected current signal through program flow writing and sends the analyzed current signal to the host through the CAN communication circuit;

[0037] Further, the program flow includes the following steps:

[0038] S1. Power on the device;

[0039] S2, parameter initialization;

[0040] S3, task allocation;

[0041] S4, zero sequence circuit tasks, communications and others;

[0042] S5, data transmission;

[0043] When the device receives a DC power supply of approximately 24V, it is powered on and initialized. The first step is to reduce the current signal through a current transformer. The current signal is then amplified through: 1. diodes for rectification and voltage stabilization; 2. transistors for signal amplification; 3. resistors for voltage and current division; and 4. capacitors for filtering and coupling. The signal is then transmitted to the microcontroller on the pulse selection unit. After the current algorithm program is burned into the MCU, the data is transmitted to the host computer via CAN communication.

[0044] The software of this product is written in C language and adopts multi-tasking architecture with good real-time performance.

[0045] Working principle: When the device collects a DC power supply of about 24V, the device is powered on and initialized. The first step is to reduce the current signal through the current transformer, and then rectify and stabilize it through the diode; the transistor amplifies the signal; the resistor divides the voltage and shunts the current; the capacitor performs filtering and coupling; the signal is then transmitted to the microcontroller on the pulse selection unit, and then the current algorithm program is burned into the MCU, and the data is transmitted to the host through CAN communication.

[0046] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. A high-voltage pulse signal acquisition unit, characterized in that: include: Pulse selection unit, current acquisition circuit and central processing unit; Wherein, the pulse selection unit is electrically connected to the current sampling circuit, the current sampling circuit is electrically connected to the current analysis circuit, and the current analysis circuit is electrically connected to the central processing unit; The current acquisition circuit is electrically connected to the MCU main circuit, and the MCU main circuit is electrically connected to the communication circuit; Secondly, the current acquisition circuit includes a current sampling loop and a current analysis loop, which are mainly used to measure and monitor the current size in the circuit and analyze the current size.

2. A high-voltage pulse signal acquisition unit according to claim 1, characterized in that: The MCU main circuit is electrically connected to a power conversion.

Images