CN203434743U - Alternating current power supply into direct current power supply and direct current power supply ripple detection apparatus used for transformer substation - Google Patents

Abstract

The utility model discloses a detection device for a substation using an alternating current power supply to enter a direct current power supply and a ripple of the direct current power supply. , a DC voltage sampling circuit (8), a filter circuit (9), a ripple voltage sampling circuit (12), etc., and the CPU module (6) is respectively connected to a voltage analog-to-digital conversion circuit (5) and a DC voltage analog-to-digital conversion circuit (10) , ripple voltage analog-to-digital conversion module (13), alarm upload communication interface (16), display screen (7), man-machine dialogue keyboard (11), alarm output circuit (14), the utility model quickly detects whether there is an AC power supply The device that enters the DC power supply can alarm in time when abnormality is detected; at the same time, it can monitor the ripple of the DC system charging device online, which can greatly improve the reliability of the DC power supply and the safe operation of the power grid.

Description

Detection device for AC power in substation into DC power and DC power ripple

Technical field:

The utility model relates to a DC power supply and a DC power ripple detection device for a transformer substation, and belongs to the technical field of power system substation maintenance.

Background technique:

1. The DC system used in the substation is an indirect grounding system. When the DC power supply is mixed with the AC power supply, it will cause the DC system to be grounded, which may cause the protection to refuse to operate or malfunction, thereby inducing serious accidents. State Grid Corporation of China's "Eighteen Major Power Grid Anti-Accident Measures of State Grid Corporation" (revised version) "5.1.1.18.3 clearly stipulates: Newly built or renovated substations, DC system insulation monitoring devices should have AC channeling DC faults Measuring and alarming functions. The current DC insulation monitoring devices do not have the measuring and alarming functions of AC channeling and DC faults. If a device with this function is to be replaced, a power outage is required, which seriously affects the reliability of power supply and affects society and society. The normal living order of the residents; if it is combined with the replacement of the DC system or the transformation of the whole station, it will be a very long-term work. Therefore, it is necessary to develop an independent detection device with the function of detecting that the AC power is mixed into the DC system. When the AC power is mixed in, the device will alarm, and can upload to the monitoring unit through the communication node, and notify the maintenance personnel to deal with it in time.

2. State Grid Corporation's "Eighteen Major Power Grid Anti-Accident Measures of State Grid Corporation" (revised version) "5.1.1.13 requires new or renovated substations to use charging and floating charging devices, and the accuracy of voltage stabilization should be better than 0.5%, stable The current accuracy is better than 1%, and the output voltage ripple coefficient is not more than 0.5%. The existing charging and floating charging devices do not meet the above requirements, and the detection of the ripple coefficient of the DC power charging device needs to be carried out with electricity. , high risk, and tedious work. Therefore, it is necessary to conduct online detection of the ripple coefficient of the DC power charging device, and a device that can alarm and upload if it exceeds the requirements of the regulations. 

Utility model content:

The purpose of the utility model is to overcome the deficiencies of the prior art and provide a device for quickly detecting whether there is an AC power supply entering the DC power supply, and alarming in time if an abnormality is detected; at the same time, it can monitor the ripple condition of the DC system charging device on-line, which can be greatly improved. To improve the reliability of the DC power supply and the safe operation of the power grid, the substation uses an AC power supply to enter the DC power supply and a DC power supply ripple detection device.

The purpose of this utility model can be achieved through the following measures: the substation uses an AC power supply to escape into the DC power supply and the DC power supply ripple detection device, which includes the positive busbar of the substation DC power supply, the negative busbar of the substation DC power supply, and the working power supply module. The positive bus bar of the DC power supply is connected to the negative bus bar of the DC power supply of the substation. The sampling circuit is respectively connected to the band-pass filter circuit and the DC voltage sampling circuit, the DC voltage sampling circuit is respectively connected to the filter circuit and the ripple voltage sampling circuit, the band-pass filter circuit is connected to the voltage analog-to-digital conversion circuit, and the filter circuit is connected to the DC voltage analog-to-digital conversion circuit, The ripple voltage sampling circuit is connected to the ripple voltage analog-to-digital conversion module, the power module is connected to the alarm upload communication interface, and the CPU module is respectively connected to the voltage analog-to-digital conversion circuit, the DC voltage analog-to-digital conversion circuit, the ripple voltage analog-to-digital conversion module, and the alarm upload communication interface. Interface, display screen, man-machine dialogue keyboard, alarm output circuit. the

Compared with the prior art, the utility model can produce the following positive effects: the utility model does not change the function of the original DC system insulation monitoring device and the wiring of the DC system, and does not affect the safe operation of the DC system of the substation. Multiple functions in one: one is the monitoring and alarming of the AC power intrusion into the DC power supply, and the other is the monitoring and alarming of the ripple of the charging device of the DC system. the

1. AC power channeling DC power monitoring and alarm:

When the AC power is mixed into the DC, the DC is isolated through the capacitor, the differential op amp, and the fast rectification

Streaming, filtering, high-speed AD, real-time detection of AC signals on the bus, and feedback to the main chip, if the AC voltage detected by the external intrusion into the DC power supply is greater than the set signal protection threshold, an alarm will be activated, through sound and light alarm and dry contacts to output alarm-related information, and can record and save this alarm-related information.

2. Ripple monitoring and alarm of DC system charging device:

Using special circuit processing such as circuit coupling, AC and DC decomposition, and pulse signal separation, the AC signal and DC signal are isolated, high-speed sampling, and comprehensive capture of AC ripple signals. The high-performance, full-range measurement method is used to effectively and accurately detect the ripple content of the DC power supply, that is, the ripple voltage value in real time, calculate the ripple coefficient in the DC, and start an alarm if it exceeds 0.5%, through sound and light alarm and intervention The contact outputs alarm-related information, and can record and save this alarm-related information.

Description of drawings:

Fig. 1 is a structural block diagram of the utility model.

The specific embodiment: the best embodiment of the present utility model is described in detail below in conjunction with accompanying drawing:

Embodiment: the detecting device (see Fig. 1) that the alternating current power supply of the substation enters into the direct current power supply and the ripple of the direct current power supply (see Fig. 1), it includes the positive busbar 1 of the direct current power supply of the substation, the negative busbar 2 of the direct current power supply of the substation, and the working power module 15 is respectively connected with the substation The positive busbar 1 of the DC power supply and the negative busbar 2 of the substation DC power supply are connected. The AC voltage sampling circuit 3, the DC voltage sampling circuit 8, and the ripple voltage sampling circuit 12 are respectively connected to the positive bus bar 1 of the DC power supply and the negative bus bar 2 of the substation DC power supply, and the AC voltage sampling circuit 3 is respectively connected to a band-pass filter with a frequency of 50HZ Circuit 4, DC voltage sampling circuit 8, DC voltage sampling circuit 8 is respectively connected to filter circuit 9, ripple voltage sampling circuit 12, band-pass filter circuit 4 is connected to 50HZ voltage analog-to-digital conversion circuit 5, filter circuit 9 is connected to DC voltage modulus The conversion circuit 10, the ripple voltage sampling circuit 12 is connected to the analog-to-digital conversion module 13, the power supply module 15 is connected to the alarm upload communication interface 16, and the CPU module 6 is respectively connected to the voltage analog-to-digital conversion circuit 5, the DC voltage analog-to-digital conversion circuit 10, and the ripple voltage An analog-to-digital conversion module 13 , an alarm upload communication interface 16 , a display screen 7 , a man-machine dialogue keyboard 11 , and an alarm output circuit 14 .

The working power supply of the utility model is taken from the DC bus bar of the substation through the power module 15, and the AC voltage sampling circuit 3, the DC voltage sampling circuit 8, and the ripple voltage sampling circuit 12 are respectively connected to the positive bus bar 1 of the DC power supply and the negative bus bar of the DC power supply of the substation. 2. When the DC bus works normally, the AC sampling circuit 3 detects the AC component of the online monitoring DC bus. The detected AC component is filtered by the 50HZ band-pass filter circuit 4 to filter out the AC component greater than 50HZ. The digital conversion circuit 5 performs analog-to-digital conversion, and then displays the value of the AC component on the display screen 7 after being processed by the CPU module 6 of the device; AC component) to obtain a more stable direct current, the analog-to-digital conversion is performed by the DC voltage analog-to-digital conversion circuit 10, and the DC bus voltage is displayed on the display screen 7 after being processed by the device CPU module 6; the ripple (50HZ-20MHZ) voltage sampling circuit 12 Detect whether there is a ripple voltage with a frequency greater than 50 Hz in the DC bus, and display the detected ripple voltage on the display screen 7 after being processed by the ripple voltage analog-to-digital conversion module 13 . If the detected AC component or ripple component exceeds the preset value, the device will give an alarm. The alarm signal can be uploaded through the alarm upload communication interface 16 or RS485 communication, so as to notify the maintenance personnel to deal with it in time and ensure the safe operation of the DC system. The detection device can set or modify relevant parameters through the man-machine dialogue keyboard 11 according to requirements. the

Claims (1)

1. transformer station scurries into the checkout gear of DC power supply and DC power supply ripple by AC power, it comprises the positive bus-bar (1) of transforming plant DC power supply, the negative busbar of transforming plant DC power supply (2), working power module (15) respectively with the positive bus-bar (1) of transforming plant DC power supply, the negative busbar of transforming plant DC power supply (2) is connected, it is characterized in that alternating current voltage sampling circuit (3), direct voltage sample circuit (8), ripple voltage sample circuit (12) accesses respectively the negative busbar (2) of positive bus-bar (1) and the transforming plant DC power supply of DC power supply, alternating current voltage sampling circuit (3) connects respectively bandwidth-limited circuit (4), direct voltage sample circuit (8), direct voltage sample circuit (8) connects respectively filter circuit (9), ripple voltage sample circuit (12), bandwidth-limited circuit (4) connects voltage analog to digital conversion circuit (5), filter circuit (9) connects direct voltage analog to digital conversion circuit (10), ripple voltage sample circuit (12) spread groove wave voltage analog-to-digital conversion module (13), power module (15) connects alarm and uploads communication interface (16), CPU module (6) connects respectively voltage analog to digital conversion circuit (5), direct voltage analog to digital conversion circuit (10), ripple voltage analog-to-digital conversion module (13), communication interface (16) is uploaded in alarm, display screen (7), interactive keyboard (11), alarm output circuit (14).

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