CN201541131U - Intelligent reactive power compensation equipment for high-voltage lines - Google Patents

Abstract

The utility model provides an intelligent powerless compensation device of a high-voltage line, comprising a fuse, an arrester, a fling-cutting switch and a capacitor. The fuse and the arrester are electrically connected with the load side of the high-voltage line; the fling-cutting switch is connected with the fuse; and the capacitor is connected with the arrester and the fling-cutting switch. The intelligent powerless compensation device of a high-voltage line further comprises a three-phase multi-winding current voltage combined type mutual inductor, a current mutual inductor and a comprehensive monitoring protection controller. The three-phase multi-winding current voltage combined type mutual inductor is connected with the power side of the high-voltage line to collect three-phase current signals and three-phase voltage signals at the power side of the high-voltage line; the current mutual inductor is arranged between the fling-cutting switch and the fuse; and the comprehensive monitoring protection controller receives the three-phase current signals and the three-phase voltage signals and issues a first control instruction to the fling-cutting switch or receives output signals of the current mutual inductor and issues a second control instruction to the fling-cutting switch. The intelligent powerless compensation device of a high-voltage line has the double functions of high-voltage line powerless compensation and low-current grounded alarm.

Description

Intelligent reactive power compensation equipment for high-voltage lines

technical field

The utility model relates to a reactive power compensation device, in particular to a high-voltage line intelligent reactive power compensation device.

Background technique

When alternating current passes through pure resistance, the electric energy is converted into heat energy, but when passing through pure capacitive or pure inductive load, no work is done, that is to say, no electric energy is consumed, which is reactive power.

The role of the reactive power compensation device in the power supply system is to improve the power factor of the power grid, reduce the loss of power supply transformers and transmission lines, improve power supply efficiency, and improve the power supply environment. So the reactive power compensation device plays a very important role in the power supply system. The reactive power compensation controller controls the input and withdrawal of capacitors from the grid according to the size and nature of the reactive power in the grid, so that the power factor in the grid remains within the set value.

Compared with developed countries, urban and rural power grids in most parts of my country generally have long power supply radius, poor voltage quality, and low power factor. If the non-functional functions are effectively balanced, not only can the loss of the power grid be greatly reduced, but also it is of great significance to improve the voltage quality. However, at present, the power factor of most urban and rural power grids in my country is low, and the reactive power is very unbalanced. Therefore, improving the power factor of the power grid, balancing reactive power, improving voltage quality, and reducing line loss are important tasks for the power system. Connecting capacitors in parallel with network inductive loads is a traditional method of compensating reactive power, which has been widely used at home and abroad. The reactive power compensation of the 10kV line generally adopts the centralized compensation method of the substation. This compensation method only compensates the reactive power required by the main transformer in the station, but has no compensation effect on the reactive power of the 10kV line and a large number of distribution transformers on the line. For The reactive power loss of the line must be compensated locally in order to truly reduce the line loss. The rural power grid has long lines, uneven load distribution, and many compensation points to be installed. If the reactive power compensation mode of the substation is copied, it will inevitably result in large investment, ineffective compensation, and inconvenient installation and maintenance. If the compensation method of installing a fixed capacity at a fixed location is adopted, although the investment is small, without any protection, capacitor burnout accidents often occur in rural power grids with poor operating conditions, causing safety hazards to the power grid operation. Moreover, the controller in the current reactive power compensation device is not highly intelligent, requiring the user to input more parameters when using it, and if the parameters are not set properly, the compensation effect will be unsatisfactory, which will affect the further promotion of the product.

倍，为了防止故障进一步扩大成两点或多点接地短路，运行人员应及时采取措施予以消除。当配电网络发生小电流接地故障时，在事先无法测知并采取有效的防范措施，仅能在事后采用拉路法及人工巡线目测法确定接地点的准确位置，拉路法需要进行大量的倒闸操作，给生产带来很大的损失，尤其是对在连续作业的生产区域及一些关键设备；而在事故发生后采取人工巡线目测法寻找接地点，每次都要耗费大量的人力、物力和时间，而单独在线路上安装单相接地保护设备造价很高，非常不经济。In addition, the single-phase ground fault of my country's distribution network has always been a difficult problem for power supply companies. my country's distribution network is a non-directly grounded neutral point grid (also known as a small ground current system). When a single-phase ground occurs, the current at the fault point is very small, and the line voltage between the three phases remains symmetrical. There is no effect on the power supply, so under normal circumstances, it is allowed to continue to run for another 1-2 hours without immediate tripping. However, after a single phase is grounded, the voltage of the other two phases to ground increases

In order to prevent the fault from further expanding into a two-point or multi-point grounding short circuit, the operating personnel should take timely measures to eliminate it. When a small current grounding fault occurs in the power distribution network, it is impossible to detect and take effective preventive measures in advance, and the accurate location of the grounding point can only be determined by the method of pulling the road and the method of manual inspection and visual inspection afterwards. The switching operation caused great loss to the production, especially for the production area and some key equipment in the continuous operation; after the accident, it took a lot of time to find the grounding point by manual line inspection and visual inspection. Manpower, material resources and time, but the cost of installing single-phase grounding protection equipment on the line alone is very high, which is very uneconomical.

Utility model content

The purpose of the utility model is to provide a high-voltage line intelligent reactive power compensation device, which combines the dual functions of high-voltage line reactive power compensation and small current grounding alarm.

In order to achieve the above purpose, the utility model proposes a high-voltage line intelligent reactive power compensation equipment including a fuse, a lightning arrester, a switching switch and a capacitor. The fuse and the lightning arrester are electrically connected to the load side of the high-voltage line, and the switching switch is connected to the above-mentioned fuse. The capacitor is connected to the arrester and the above-mentioned switching switch. High-voltage line intelligent reactive power compensation equipment also includes three-phase multi-winding current-voltage combined transformer, current transformer and comprehensive monitoring and protection controller. The three-phase multi-winding current-voltage combined transformer is connected to the power supply side of the high-voltage line, and the three-phase current signal and three-phase voltage signal on the high-voltage line power supply side are collected; the current transformer is set between the switching switch and the fuse; comprehensive monitoring protection control The controller receives the above-mentioned three-phase current signal and three-phase voltage signal and sends a first control command to the switching switch, or the integrated monitoring and protection controller receives the output signal of the above-mentioned current transformer and sends a second control command to the switching switch.

In the utility model, the comprehensive monitoring and protection controller includes an acquisition unit, an input and output unit, a human-computer interaction unit, a communication unit, a power supply unit, a dual-port random access memory communication, a digital signal processor and a microprocessor, wherein the acquisition The unit and the input and output unit are electrically connected to the above-mentioned digital signal processor, the human-computer interaction unit and the communication unit are electrically connected to the microprocessor, and the power supply unit, the microprocessor and the digital signal processor are respectively electrically connected to the above-mentioned dual-port random access memory for communication .

In the utility model, the acquisition unit includes a transformer, a signal conditioning circuit and an analog-to-digital conversion chip, and the transformer receives the three-phase current signal and the three-phase voltage signal collected from the power supply side by the three-phase multi-winding current-voltage combined transformer, and The obtained low voltage signal and small current signal are input to the signal conditioning circuit, the output of the signal conditioning circuit is connected to an analog-to-digital (AD) conversion chip, and the output of the analog-to-digital conversion chip is connected to a digital signal processor.

In the utility model, the communication unit is a GSM short message sending module or a GPRS wireless transmission module, and the GSM short message sending module or the GPRS wireless transmission module receives the output of the above-mentioned microprocessor.

In the utility model, the human-computer interaction unit is a light emitting diode, a keyboard or a display screen.

In the utility model, the switching switch is a vacuum circuit breaker with a single-phase permanent magnet mechanism.

To sum up, the utility model not only has the function of intelligent reactive power compensation, but also has the function of single-phase small current grounding alarm. The overcurrent protection function of the integrated protection controller and the current transformer installed on the vacuum circuit breaker together constitute the overcurrent protection, which can also effectively prevent the surge current from harming the capacitor, and there is no need for on-duty personnel or maintenance personnel to go to the scene Perform meter reading.

Description of drawings

Fig. 1 is a functional block diagram of the utility model embodiment.

Figure 2 is a schematic diagram of the installation of the high-voltage line intelligent reactive power compensation equipment in Figure 1 when it is actually used.

Fig. 3 is a circuit diagram of a comprehensive monitoring and protection controller of the high-voltage line intelligent reactive power compensation equipment in Fig. 1 .

Detailed ways

In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments will be described in detail below together with the accompanying drawings.

Fig. 1 is a functional block diagram of an embodiment of the utility model, and Fig. 2 is a schematic diagram of the installation of the high-voltage line intelligent reactive power compensation device in Fig. 1 in actual use, please refer to Fig. 1 to Fig. 2 . The high-voltage line intelligent reactive power compensation equipment includes a fuse 11 , an arrester 12 , a switching switch 13 and a capacitor 14 . The fuse 11 and the arrester 12 are electrically connected to the load side of the high-voltage line, and the switching switch 13 is connected to the above-mentioned fuse 12 . The capacitor 14 is connected to the switching switch 13 and the arrester 12 . The high-voltage line intelligent reactive power compensation equipment also includes a three-phase multi-winding current-voltage combined transformer 16 , a current transformer 17 and a comprehensive monitoring and protection controller 18 . The three-phase multi-winding current-voltage combined transformer 16 is connected to the high-voltage line power supply side, and collects three-phase current signals and three-phase voltage signals on the high-voltage line power supply side. The current transformer 17 is arranged between the switching switch 13 and the fuse 12 . The comprehensive monitoring and protection controller 18 receives the above-mentioned three-phase current signal and three-phase voltage signal and sends the first control command to the switching switch 13, or the comprehensive monitoring and protection controller 18 receives the output signal of the above-mentioned current transformer and sends out the second control command To switch 13.

In this embodiment, the integrated monitoring and protection controller 18 includes an acquisition unit 181, an input and output unit 182, a human-computer interaction unit 184, a communication unit 185, a power supply unit 186, a dual-port random access memory communication 187, and a digital signal processor 188 and a microprocessor 189, wherein the acquisition unit 181 and the input and output unit 182 are electrically connected to the above-mentioned digital signal processor 188, the human-computer interaction unit 184 and the communication unit 185 are electrically connected to the microprocessor 189, and the microprocessor 189 and the digital signal Processor 188 communicates through dual-port random access memory (RAM) 187 . Among them, the digital signal processor is TMS320LF2407, and the microprocessor is M16C62P

The acquisition unit 181 includes a transformer 181a, a signal conditioning circuit 181b and an analog-to-digital conversion chip 181c. The transformer 181a receives the three-phase current signal and the three-phase voltage signal collected from the power supply side by the three-phase multi-winding current-voltage combined transformer 16, and inputs the obtained low voltage signal and small current signal to the signal conditioning circuit 181b, and the signal The conditioning circuit 181b conditions the input low voltage signal and small current signal to obtain a conditioning signal, and the analog-to-digital conversion chip 181c performs analog-to-digital conversion on the input conditioning signal. The specific principles of the transformer 181a, the signal conditioning circuit 181b and the analog-to-digital conversion chip 181c are common knowledge for those skilled in the art, and will not be described in detail here.

When performing reactive power compensation, the digital signal processor 188 calculates the received signal to obtain the active power, reactive power and power factor on the line, and compares it with the set value in the digital signal processor 188, and then judges whether Send the first control command to the switching device 13, and this setting value can be set by using the keyboard 184a or the display screen 184b. Here, we take reactive power as an example for illustration. When the detected reactive power is greater than the set reactive power value, an input signal is sent to the vacuum circuit breaker 13, and the capacitor 14 is used to compensate the required reactive power. Otherwise, a cutting signal is sent to the vacuum circuit breaker 13, so that the capacitor 14 is withdrawn from the grid. In this embodiment, the switching switch 13 is a vacuum circuit breaker with a single permanent magnet mechanism. In the past, no matter whether the reactive power compensation equipment on the column used a vacuum contactor or a circuit breaker, the three-phase capacitor was switched on or off at one time, but since the three phases were switched on or off at the same time, at most one phase zero-crossing switching was possible. , while the other two phases cannot put in or remove the capacitor at the zero-crossing position. Inrush current phenomenon will be generated when it is put into use, and there will be overvoltage when the capacitor is cut. The single-phase permanent magnet mechanism vacuum circuit breaker can realize zero-crossing switching, prevent the impact of inrush current and overvoltage, and prolong the service life of the capacitor.

In addition, the high-voltage line intelligent reactive power compensation equipment in this embodiment also has a low-current grounding alarm function when a single-phase grounding fault occurs. The specific working principle is as follows: the comprehensive monitoring and protection controller 18 obtains zero-sequence current and zero-sequence voltage according to the three-phase current signal and three-phase voltage signal on the power supply side collected by the three-phase multi-winding outdoor high-voltage combined transformer 16 . How the digital signal processor 188 calculates the zero-sequence current and zero-sequence voltage according to the three-phase current signals and three-phase voltage signals on the power supply side is common knowledge for those skilled in the art, and will not be described in detail here. When a single-phase ground fault occurs, the three-phase voltage and three-phase current on the power supply side will be unbalanced, and the zero-sequence voltage and zero-sequence current will also change. The digital signal processor 188 will actually obtain the zero-sequence voltage and zero-sequence The current is compared with the set values of zero sequence voltage and zero sequence current. If the field setting data is less than 10A and zero-sequence voltage is less than 30V, it means that the small current grounding fault does not occur, then the setting value of zero-sequence current can be 10A, and the setting value of zero-sequence voltage can be 30V. When the actually calculated zero-sequence voltage and zero-sequence current are greater than the set values of the zero-sequence voltage and zero-sequence current, the microprocessor 189 controls the human-computer interaction unit 184 to give an alarm. In this embodiment, the human-computer interaction unit 184 is Light emitting diode 184c, and the light emitting diode 184c indicates an alarm.

Further, in this embodiment, a current transformer 17 is also arranged between the fuse 11 and the switching switch 13, and the current transformer 17 collects the actual value of the three-phase current signal on the capacitor 14, and outputs it to the comprehensive monitoring protection control device 18, the integrated monitoring and protection controller 18 compares the actual value of the three-phase current signal on the input capacitor 14 with the set value of the three-phase current signal on the capacitor 14, and when the actual value is greater than the set value, the integrated monitoring and protection control The device 18 sends a cutting signal (second control command) to the switching switch 13 to make the capacitor 14 withdraw from the grid, otherwise the switching switch 13 remains in the input state. In this way, the capacitor 14 can be prevented from being burned out or even exploded. At present, the overcurrent protection of most products is protected by the fuse 11, and the protection is not too precise. Moreover, the damage to the capacitor 14 caused by the inrush current usually breaks down gradually. The protection of the fuse 11 cannot be too precise and in place. Here, the integrated monitoring and protection controller 18 is used as the main protection. The protection current can be set according to the actual situation on site to achieve precise protection. The fuse 11 is used as a backup protection to perfect the overcurrent protection.

The communication unit 185 in this embodiment may be a GSM short message sending module or a GPRS wireless transmission module. The GPRS wireless transmission module cooperates with the GPRS wireless receiving module 20 and the background software of the substation or the dispatching center to monitor various information on the line (whether the line has a single-phase ground short circuit alarm, switch switching status, three-phase voltage, three-phase current , Power factor, active power, reactive power, etc.) real-time monitoring. The GSM short message sending module sends all kinds of information on the line and the switching status of the switch to the on-duty personnel of the substation through regular sending. Of course, if there is a fault in the capacitor, a fault in the line, etc., which lead to switch protection action or small current grounding, etc., it will be sent to the duty personnel in time. The operating principle of the GSM short message sending module or the GPRS wireless transmission module belongs to common knowledge for those with common knowledge in the art, and will not be described in detail here.

It can be seen that the high-voltage line intelligent reactive power compensation device in this embodiment not only has the function of intelligent reactive power compensation, but also has the function of single-phase small current grounding alarm. The overcurrent protection function of the integrated protection controller and the current transformer installed on the switching switch can also effectively prevent the damage of the surge current to the capacitor, and there is no need for on-duty personnel or maintenance personnel to go to the scene Perform meter reading.

The specific implementation cases described in the utility model are only preferred implementation examples of the utility model, and are not used to limit the implementation scope of the utility model. That is, all equivalent changes and modifications made according to the content of the patent scope of the utility model should be regarded as the technical category of the utility model.

Claims (7)

1. A high-voltage line intelligent reactive power compensation device, including a fuse, a lightning arrester, a switching switch and a capacitor, the fuse and the lightning arrester are electrically connected to the load side of the high-voltage line, the switching switch is connected to the above-mentioned fuse, and the capacitor is connected to the above-mentioned switching switch And the above lightning arrester is characterized in that it also includes: Three-phase multi-winding current-voltage combined transformer, connected to the power supply side of the high-voltage line, and collecting three-phase current signals and three-phase voltage signals on the power supply side of the high-voltage line; The current transformer is arranged between the switching switch and the fuse; The comprehensive monitoring and protection controller receives the above-mentioned three-phase current signal and three-phase voltage signal and sends the first control command to the switching switch, or the comprehensive monitoring and protection controller receives the output signal of the above-mentioned current transformer and sends the second control command to the Toggle switch. 2. The high-voltage line intelligent reactive power compensation device according to claim 1, wherein the integrated monitoring and protection controller includes an acquisition unit, an input and output unit, a human-computer interaction unit, a communication unit, a power supply unit, a dual-port Random access memory communication, digital signal processor and microprocessor, wherein the acquisition unit and the input and output unit are electrically connected to the above-mentioned digital signal processor, the human-computer interaction unit and the communication unit are electrically connected to the microprocessor, the power supply unit, the microprocessor The device and the digital signal processor are respectively electrically connected to the above-mentioned dual-port random access memory for communication. 3. The high-voltage line intelligent reactive power compensation device according to claim 2, wherein the acquisition unit includes a transformer, a signal conditioning circuit and an analog-to-digital conversion chip, and the transformer receives a three-phase multi-winding current-voltage combined transformer Collect the three-phase current signal and three-phase voltage signal from the power supply side, and input the obtained low-voltage signal and small current signal to the signal conditioning circuit, the output of the signal conditioning circuit is connected to the analog-to-digital conversion chip, and the analog-to-digital conversion chip The output is connected to a digital signal processor. 4. The high-voltage line intelligent reactive power compensation device according to claim 2, wherein the communication unit is a GSM short message sending module or a GPRS wireless transmission module. 5. The high-voltage line intelligent reactive power compensation device according to claim 2, wherein the human-computer interaction unit is a light-emitting diode, a keyboard or a display screen. 6. The high-voltage line intelligent reactive power compensation device according to claim 2, wherein the digital signal processor is TMS320LF2407, and the microprocessor is M16C62P. 7. The high-voltage line intelligent reactive power compensation device according to any one of claims 1-6, wherein the switching switch is a vacuum circuit breaker with a single-phase permanent magnet mechanism.

Images