CN203119559U - Distributed direct-current power source monitoring device - Google Patents

Abstract

A distributed direct-current power monitoring device comprises a main controller, a liquid crystal display, a time synchronizing module, a power source management module, background monitoring equipment, a background monitoring communication interface, a main controller communication interface, a liquid crystal display interface, a time synchronizing interface, a system state collecting module, a direct-current insulation detection module, a storage battery detection module and a bus. The time synchronizing module, the direct-current insulation detection module and the storage battery detection module are selective, and the main controller, the power source management module, the system state collection module, the direct-current insulation detection module and the storage battery detection module are respectively connected with the bus. The distributed direct-current power monitoring device can be used for various application places, and modularized design is adopted, so that the device is powerful in function, high in instantaneity and convenient to manage; and an expert system is embedded, battery operating conditions are detected through data collected in a long time, health conditions and performance assessment of a storage battery are provided, and a maintenance suggestion scheme is provided.

Description

Distributed DC power monitoring device

technical field

The utility model specifically relates to a distributed DC power monitoring device.

Background technique

With the continuous development of the society, the power consumption is getting higher and higher, and the requirements for the power system are getting higher and higher. The reliability, stability, scalability and strictness of the battery charge and discharge management of the system are gradually becoming The most concerned issue of the power system. Power supply and distribution departments such as power plants and substations (stations) usually use battery DC power supplies as uninterruptible power supplies for devices such as control, signal, protection, emergency lighting, DC oil pumps, and opening and closing. The reliability of the DC power supply directly affects the power supply. The safe operation of the power distribution system, and the strength of the function will affect the healthy operation of the system and the service life of the battery. At present, the domestic power operation DC power supply monitoring system mainly adopts the centralized monitoring method of the DC power supply system placed in the main control room. With the development of intelligent substation construction, the hierarchical distributed architecture will become the mainstream. In the future, the overall design of the intelligent station system will mainly be Optimize the use of area and install the equipment on site. Therefore, when the main transformer side protection measurement and control, low voltage side protection measurement and control, intelligent terminal, merging unit and GIS equipment are far away from the main control room, the DC power supply needs to add a power distribution screen and use a large number of cables Supply power to the equipment, which will increase the difficulty of cable wiring and poor economy. At the same time, if the distance is too long, the sampling accuracy of signal attenuation will be inaccurate, resulting in misoperation of equipment switches. The existing DC unit monitoring devices are generally only suitable for lead-acid For batteries, the charging strategy is a simple constant current and constant voltage method, which is not suitable for charging management of lithium batteries, etc. The maintenance work of the battery is relatively simple, and the regular charging method cannot provide maintenance suggestions. Once the battery has a problem, it is easy to cause DC power The system is paralyzed, and there is no battery balance control, which has a great impact on battery life. The time synchronization method of the existing device is single, and the application occasions are limited. The insulation detection module mostly uses the injection signal method, which is likely to cause problems such as protection malfunction. Most of the original monitoring devices use fieldbus to provide up-to-date protocols, which cannot meet the needs of smart substation construction. The power input mode of the charging module is single, and there are no multiple power input interfaces such as solar energy and wind energy. The original DC power monitoring device no longer satisfies the development of applications.

Utility model content

In order to solve the deficiencies of the prior art, the utility model specifically discloses a distributed DC power monitoring device.

Concrete scheme of the present utility model is as follows:

A distributed DC power monitoring device, including a main controller, a liquid crystal display, a time synchronization module, a power management module, a background monitoring device, a background monitoring communication interface, a main controller communication interface, a liquid crystal display interface, a time synchronization interface, A system state acquisition module, a DC insulation detection module, a battery detection module, and a bus; the main controller, a power management module, a system state acquisition module, a DC insulation detection module, and a battery detection module are respectively connected to the bus; the time synchronization module is connected to the bus The timing interface is connected, and the communication mode supported by the timing interface is RS485 or ETH; the liquid crystal display is connected with the LCD interface, and the communication mode supported by the LCD interface is RS485 or parallel interface; the main control The communication interface of the device is connected to the bus, and the communication mode supported by the communication interface of the main controller is RS485, CAN, ETH or power line carrier; the background monitoring communication interface is connected with the main controller, and the communication interface supported by the background monitoring communication The communication mode is RS485, CAN, ETH or power line carrier.

The power management module includes a power switching control module, a charging process control module, and a battery balance control module.

The system state acquisition module includes an analog quantity acquisition module, a switch quantity acquisition module, and a fault detection module.

The DC insulation detection module includes a bus insulation monitoring module, a branch insulation monitoring module, and an AC mixing monitoring module.

The battery detection module includes a battery voltage detection module, a battery pack temperature detection module, and a battery pack internal resistance detection module.

The power management module of the distributed DC power monitoring device can select passive balancing and active balancing according to the degree of battery imbalance. The status acquisition module of the distributed DC power supply monitoring device can collect AC input, DC output, battery status, and switching values. The main controller can judge the working status of the system in time and make control according to the collected information.

The insulation monitoring module of the distributed DC power supply monitoring device can perform AC mixed detection on the DC bus and feeder. The device can detect the direct short circuit between the AC and the DC bus, the AC mixed into the DC bus through capacitive coupling, and the AC mixed into the DC bus through the resistance. The mixed-in line number can be selected. For the ungrounded system of the power frequency power supply, a capacitor can be connected between the neutral line and the ground when necessary, and the function of detecting the power frequency mixed into the DC bus can also be realized. During normal operation, the device can check the relative value of the DC bus power frequency AC voltage and the AC current of the 16 lines with the largest AC current. The insulation monitoring module of the distributed DC power supply monitoring device adopts a detection method combining a balanced bridge and an unbalanced bridge to detect the bus voltage, unipolar-to-ground voltage, and bus-to-ground insulation resistance.

The beneficial effects of the utility model are:

(1) The distributed DC power supply monitor supports multiple communication methods such as ETH, CAN, and 485, and is suitable for various occasions. It supports the 61850 protocol and can be directly connected to smart substations. It has 1588 time synchronization and B code pairs. Various time synchronization methods such as time synchronization and NTP network time synchronization have a wide range of applications.

(2) It has constant current constant voltage, multi-stage constant current, constant power and other charging methods to choose from, and is suitable for various batteries such as lead-acid batteries and lithium iron phosphate batteries. It has a battery expert system, which applies some management knowledge of expert engineers to battery monitoring and management, provides battery health status, performance evaluation, and maintenance and maintenance suggestions based on long-term operation monitoring results. It has the function of battery balance control to prevent the occurrence of overvoltage and undervoltage of the single battery, and perform balance control to effectively increase the service life of the battery. Real-time monitoring of battery temperature, SOC and other information to prevent over-temperature, over-charge, over-discharge and other phenomena.

(3) The insulation detection module adopts the leakage current detection method without injecting signals into the system, which improves the stability of the system operation. It adopts the combination of balanced bridge and unbalanced bridge to detect the insulation status of the busbar and the AC mixed status. By cooperating with the leakage current sensor, the functions of grounding line selection and AC mixed line selection can be realized.

(4) Multi-power access, using solar energy, wind energy and other power sources to give full play to the advantages of different types of power sources, improve the level of comprehensive utilization of various energy sources, and obtain the peak and valley operating status of the power grid through communication with the background. electricity to achieve energy saving and consumption reduction. Modular design is adopted, and the functions are relatively independent, which is convenient for fault finding and module replacement.

(5) Distributed DC power supply monitoring device is used, which saves a lot of cables, and the wiring is simple. Even if there is a single-point grounding, it is not easy to cause protection malfunction. The system runs stably. Designed with a high degree of protection for outdoor applications.

Description of drawings

Figure 1 The overall structure of the distributed DC power monitoring device;

Fig. 2 Work flow diagram of the status acquisition module of the distributed DC power monitoring device;

Fig. 3 The circuit diagram of the AC mixing detection circuit of the insulation monitoring module of the distributed DC power monitoring device;

Fig. 4 The insulation detection circuit diagram of the busbar and branch circuit of the insulation monitoring module of the distributed DC power supply monitoring device;

In Figure 1, 1 main controller, 2 LCD display, 3 time synchronization module, 4 system state acquisition module, 5 DC insulation detection module, 6 battery detection module, 7 LCD display interface, 8 power management module, 9 time synchronization interface , 10 main controller communication interface, 11 background monitoring equipment, 12 background monitoring equipment communication interface, 13 bus, 81 power switch control module, 82 charging process control module, 83 battery balance control module, 41 analog quantity acquisition module, 42 switching value Acquisition module, 43 fault detection module, 51 bus insulation monitoring module, 52 branch circuit insulation monitoring module, 53 AC mixing monitoring module, 61 battery voltage detection module, 62 battery pack temperature detection module, 63 battery pack internal resistance detection module.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in detail:

As shown in Figure 1, a distributed DC power supply monitoring device includes a main controller 1, a liquid crystal display 2, a time synchronization module 3, a power management module 8, a background monitoring device 11, a background monitoring device communication interface 12, a main control Device communication interface 10, liquid crystal display interface 7, time synchronization interface 9, system status acquisition module 4, DC insulation detection module 5, battery detection module 6, bus 13;

The time synchronization module 3 is connected with the time synchronization interface 9, and the communication mode supported by the time synchronization interface 9 is RS485 or ETH; the liquid crystal display 2 is connected with the liquid crystal display interface 7, and the communication mode supported by the liquid crystal display interface 7 is RS485 or parallel interface; The communication interface 10 of the controller is connected with the background monitoring equipment 11, and the communication mode supported by the communication interface 10 of the main controller and the communication interface 12 of the background monitoring equipment is RS485, CAN, ETH or power line carrier. The power management module 8 includes a power switching control module 81, a charging process control module 82, and a battery balance control module 83; the system state acquisition module 4 includes an analog quantity acquisition module 41, a switch quantity acquisition module 42, and a fault detection module 43; a DC insulation detection module 5 includes a bus insulation monitoring module 51, a branch insulation monitoring module 52, and an AC mixing monitoring module 53; the battery detection module 6 includes a battery voltage detection module 61, a battery pack temperature detection module 62, and a battery pack internal resistance detection module 63; the main controller 1. The power management module 8, the system state acquisition module 4, the DC insulation detection module 5, and the storage battery detection module 6 are respectively connected to the bus 13 for data communication. The main controller 1 receives and processes data through the main controller communication interface 10 .

The main monitoring pair of the distributed DC power supply monitoring device supports the IEC61850 protocol, and also supports multiple optional carrier modes such as CAN, Ethernet, and power line carrier. The main monitor of the distributed DC power supply monitoring device supports multiple time synchronization methods such as 1588 time synchronization, B code time synchronization, and NTP network time synchronization, and is used in various applications.

The distributed DC power supply monitoring device is embedded with an expert system, which provides relevant information such as battery parameters through the human-computer interaction interface, detects battery operation conditions through long-term collected data, provides battery health status, performance evaluation, and provides maintenance and maintenance suggestions .

The distributed DC power supply monitoring device is interfaced with the power system to obtain the peak and valley operation information of the power grid, and realize reasonable adjustment of the charging period while ensuring the stable operation of the DC system. The power management module of the distributed DC current monitoring device can use different charging methods according to different characteristics of lead-acid batteries, lithium batteries, etc., so that the monitoring device can be applied to various battery power supply occasions. The power management module of the distributed DC power supply monitoring device uses clean energy as much as possible while ensuring the stability of the power supply system, and uses the maximum power judgment method to determine which power supply to use as the current power supply. During the working process, 1 master and 1 backup work mode is adopted to ensure the reliability of the input power supply to the greatest possible extent. The power management module of the distributed DC power monitoring device can select passive balancing and active balancing according to the degree of battery imbalance.

The working process of the status acquisition module of the distributed DC power supply monitoring device is shown in Figure 2. It can collect AC input, DC output, battery status, and switching values. The collected data is sent after signal conditioning, AD conversion, and optocoupler isolation processing. To the CPU, the main controller judges the working status of the system in time according to the collected information and makes control.

The AC mixed-in detection circuit diagram of the insulation monitoring module of the distributed DC power supply monitoring device is shown in Figure 3. It can perform AC mixed-in detection on the DC bus and feeder. The device can detect the direct short circuit between the AC and the DC bus. In the case of various fault conditions such as resistance mixed into the DC bus, the mixed line number can be selected. For the ungrounded system of the power frequency power supply, a capacitor can be connected between the neutral line and the ground when necessary, and the function of detecting the power frequency mixed into the DC bus can also be realized. During normal operation, the device can check the DC bus power frequency AC voltage and AC current The relative value of the AC current of the maximum 16 lines.

The distributed DC power supply monitoring device insulation monitoring module bus and branch insulation detection circuit diagram is shown in Figure 4. The detection method combined with the balanced bridge and the unbalanced bridge is used to control the bus voltage, unipolar-to-ground voltage, and bus-to-ground insulation resistance. to test. Branch insulation resistance detection adopts the DC leakage current detection method, which does not need to inject signals into the system and improves the stability of the system operation.

Claims (5)

1. distributed DC apparatus for monitoring power supply, it is characterized in that, comprise master controller, LCDs, to the time module, power management module, background monitoring equipment, background monitoring communication interface, master controller communication interface, LCDs interface, to the time interface, system mode acquisition module, D.C. isolation detection module, storage battery detection module, bus; Described master controller, power management module, system mode acquisition module, D.C. isolation detection module, storage battery detection module link to each other with bus respectively; Described to the time module with to the time interface link to each other, described to the time interface support communication modes be RS485 or ETH; Described liquid crystal display links to each other with the LCDs interface, and the communication modes of described LCDs interface support is RS485 or parallel interface; The communication interface of described master controller links to each other with bus, and the communication modes of the communication interface support of described master controller is RS485, CAN, ETH or power line carrier; Described background monitoring communication interface links to each other with master controller, and the communication modes of described background monitoring communication interface support is RS485, CAN, ETH or power line carrier.

2. a kind of distributed DC apparatus for monitoring power supply as claimed in claim 1 is characterized in that, described power management module comprises power supply switching controls module, charging flow control module, battery balanced control module.

3. a kind of distributed DC apparatus for monitoring power supply as claimed in claim 1 is characterized in that, described system mode acquisition module comprises analogue collection module, switch acquisition module, fault detection module.

4. a kind of distributed DC apparatus for monitoring power supply as claimed in claim 1 is characterized in that, described D.C. isolation detection module comprises bus insulation monitoring modular, branch road insulating monitoring module, exchanges and sneak into monitoring modular.

5. a kind of distributed DC apparatus for monitoring power supply as claimed in claim 1 is characterized in that, described storage battery detection module comprises battery tension detection module, batteries temperature detecting module, batteries internal resistance detection module.

Images