CN201508408U - Intelligent battery status wireless monitoring device for substation DC panel - Google Patents

Abstract

The utility model relates to a wireless monitoring device for the status of an intelligent storage battery for a substation DC screen. The device is composed of a data acquisition part and a wireless communication part, wherein the data acquisition part is composed of a data acquisition module, a current sensor, a signal acquisition circuit and a DSP digital signal processor. The wireless communication part is composed of RF radio frequency circuit and antenna; each battery is connected to a data acquisition module, and the batteries are connected in series to form a battery pack, and a current sensor is added to the data acquisition module of one of the batteries in each battery pack. The data acquisition module and the current sensor are respectively connected to the signal acquisition circuit, the signal acquisition circuit is connected to the DSP digital signal processor, the DSP digital signal processor is connected to the RF radio frequency circuit, and the RF radio frequency circuit sends the data to the main control station through the antenna. The utility model has the advantages of low maintenance cost, high flexibility and good expansibility.

Description

Intelligent battery status wireless monitoring device for substation DC panel

technical field

The utility model relates to a wireless monitoring device for the state of an intelligent accumulator used in a DC screen of a substation, which belongs to the technical field of accumulator detection.

Background technique

The DC system provides reliable DC power for control, signal, relay protection, automatic devices and emergency lighting in the substation. It also provides reliable operating power for the operation of circuit breakers, etc. Therefore, a reliable DC system is a safe and stable substation. necessary conditions for operation. The battery pack is in a hot standby state under normal operation, and is float-charged by the charger. In the event of an accident where the AC power is completely lost, the battery pack bears the load of the DC system. As a backup power supply, the battery pack plays a role that cannot be ignored. In addition to the conventional equalization or floating charge management, it is also necessary to inspect the daily working status of the battery pack. At present in China, most of the maintenance and performance evaluation of substation battery packs stay on the traditional detection method. The daily detection methods of substation batteries mainly include:

(1) Determine the capacity of the battery through checking discharge (once a year);

(2) The characteristics test of the large output current of the battery, that is, the discharge experiment is carried out by using the discharge module (once a year);

(3) Measure the terminal voltage of the battery pack (including a single battery);

The most direct detection method of the battery is to conduct a discharge test to measure the actual capacity of the battery. The existing discharge operation is usually carried out by variable resistors, carbon rods or in the water flow of the tank. The load resistance is adjusted by manual or relay switching, and the voltage of each battery is manually measured. The labor intensity is high, the safety is poor, and the steady flow characteristics are also poor. , The steady flow accuracy of step regulation is generally greater than 5%. This method will destroy the integrity of the backup energy source and cannot be used frequently, so a discharge test is generally carried out once a year. This detection method cannot monitor the state of the working battery, and cannot find faulty batteries in time. The battery conductivity tester that is widely used in China can accurately reflect the operating status of the battery, but this measurement is also carried out regularly, and it is also impossible to realize the online monitoring of the battery.

In view of the above reasons, substations often use wired online monitoring systems to monitor the operating status of battery packs in real time. The failure of the battery is mainly manifested in insufficient terminal voltage, battery open circuit or significant increase in internal resistance, insufficient capacity or instantaneous discharge current that does not meet the load requirements, etc. At present, the main online monitoring system in China has test equipment such as battery voltage inspector to test the battery terminal voltage, but this inspector only inspects the terminal voltage of the battery, and it is measured when the battery is in the floating charge state, so it cannot be correct. Response to battery operating status.

With people's in-depth research on battery monitoring equipment, a more advanced wired online monitoring system has come out, which can monitor the battery's terminal voltage, current, internal resistance, etc. online. The utility model changes the wired system into a wireless monitoring system on the basis of the original monitoring function of the wired monitoring system.

Contents of the invention

The purpose of this utility model is to provide a wireless monitoring device for the state of the intelligent storage battery used in the substation DC panel. Control station for data communication.

The technical scheme of the utility model is: a wireless monitoring device for the state of an intelligent storage battery for a substation DC screen, which is composed of a data acquisition part and a wireless communication part, wherein the data acquisition part is composed of a data acquisition module, a current sensor, a signal acquisition circuit, and a DSP digital signal processor Composition, characterized in that: the wireless communication part is composed of two parts: RF radio frequency circuit and antenna; the relationship between each part is: each battery is connected to a data acquisition module, and the batteries are connected in series to form a battery pack. A current sensor is added to the data acquisition module of a storage battery, and the data acquisition module and the current sensor are respectively connected to the signal acquisition circuit, the signal acquisition circuit is connected to the DSP digital signal processor, the DSP digital signal processor is connected to the RF radio frequency circuit, and the RF radio frequency circuit connects the Data is sent to the master control station.

The above-mentioned intelligent battery status wireless monitoring device for substation DC panels is characterized in that the data acquisition module integrates a voltage sensor, adopts a compact design, takes power from the battery itself, and is installed at the nearest monitoring point of each battery.

The above-mentioned wireless monitoring device for intelligent battery status for substation DC panels is characterized in that: the wireless communication part adopts a standard 10cm antenna, and the antenna is fixed on the RF radio frequency circuit. When the antenna height is 1.5m, the transmission distance can reach 600m, and can Provide 8 to 16 channels and various transmission rates.

The beneficial effects of the utility model are:

(1) Low maintenance cost

Wired systems have high wiring costs and high labor intensity, and the maintenance and upgrade costs of communication lines are relatively high. The lines are vulnerable to damage, mechanical wear, and line aging. Zero wiring costs are unmatched by wired systems.

(2) High flexibility

The layout of the traditional wired system is limited by the wiring pattern, which will bring unpredictable difficulties to the wiring and debugging projects; if the wireless system is used, the above problems can be avoided, and there is no need to be limited by space, and there is greater freedom within a certain range Especially when changing the location of the battery pack, it can better reflect its simple and convenient characteristics.

(3) Good scalability

The expansion of the wired system is weaker than that of the wireless system. If you want to add a new battery pack, you need to rewire, while the wireless system only needs to add wireless communication equipment to the battery pack.

(4) The communication module adopts micro-transmitting power, only 10mW, and has high receiving sensitivity, and the receiving sensitivity at 9600 baud rate reaches -115db;

Description of drawings

Fig. 1 is a structural diagram of the battery on-line monitoring system of the present invention.

Fig. 2 is a communication structure diagram of the battery on-line monitoring system of the present invention.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described.

In Figure 1, N individual batteries that need to be monitored are connected in series to form a battery group, and then merged into the battery working group. The data acquisition module of each battery needs to include a detection module that monitors the terminal voltage of the battery. Select a data acquisition module in each battery pack to join the detection module that monitors the series current of the battery pack, and then send the collected status signals to data processing. The device performs data processing, and then sends it to the radio frequency communication module including RF radio frequency circuit, antenna and other structures to communicate with the main control station.

Fig. 2 shows the communication structure diagram of the battery on-line monitoring system in the utility model. One storage battery is a communication node, and N storage batteries form N communication nodes, all of which are controlled by the master control station. The communication mechanism adopted by this master-multiple-slave communication system includes polling and reporting methods. Each communication node uploads the status information of the node to the master control station at regular intervals, and the master control station sends data upload commands to each sub-node according to the address sequence of each node. This command has a node address, only the node with this address returns its own state information, and other nodes keep the original state. Each node only opens the communication module when it enters the sending work, and usually closes the sending module, and does not receive or send any data. Such a communication mechanism can reduce or eliminate the collision problem of communication data, and the reliability of data communication is the basis for ensuring the normal collection of the system.

The data acquisition part is responsible for the acquisition and data processing of each state quantity of the battery, and then the communication part performs data communication with the main control station. The data acquisition part is composed of current sensor, voltage sensor, signal acquisition circuit, DSP digital processor and so on. The sensor and signal acquisition circuit are responsible for the acquisition of state quantities, and then send the collected signals to the DSP digital processor for data processing to obtain the data required by the master control station. The communication part is composed of RF radio frequency circuit, antenna and other parts. The monitoring data is transmitted through RF radio frequency, without data transmission lines, and the antenna is properly led out according to the usage environment of the module. The master control station is also installed wirelessly to receive and send communication instructions and data. This system can simultaneously monitor the status of the terminal voltage, current and internal resistance of all batteries in the substation online.

One battery uses one data acquisition module. All battery data modules have a 2-byte address, and the node address is used to identify the transmitted data, which is equivalent to numbering the battery and is easy for the master control station to identify. A total of 65,535 node addresses are allowed, that is, 65,535 batteries are allowed to be connected to the system, which fully meets the requirements of the substation for the number of batteries. In each battery pack connected in parallel to the system, each battery has a data acquisition module, which is responsible for collecting the terminal voltage of a single battery. In the battery pack, a current sensor is added to the data acquisition module of one of the battery packs to collect the series current of the battery pack. In order to facilitate the communication system to identify different state semaphores, an identifier is added to the data of each state signal.

The communication control mechanism between the storage battery and the main control station is described as follows:

(1) Polling mechanism. Each storage battery node samples the state signal every t seconds, but does not send the state signal to the master control station, but saves it in the memory. The master control station adopts the polling method, and sends data upload commands to the sub-nodes at regular intervals ΔT according to the address sequence of each sub-node, or the node sequence configured by the computer control system. The communication packet is sent with the address, only the node with the same address returns the status signal, and other nodes keep the original status. When the system has N sub-nodes for polling, the total status data update time is N×ΔT. The polling mechanism can effectively prevent communication data collision.

(2) Reporting mechanism. The battery communication node is powered on and is in the receiving state. When the master control station issues a start command, all sub-nodes enter the working state. After an appropriate delay, the status signal is sampled once and sent to the master control station, and the data is sampled and sent every N×ΔT seconds. The communication module is only turned on when entering the sending work, and the sending module is turned off at ordinary times, and no data is received or sent. The periodic data collection and transmission of the nodes, the intermediate delay adopts the modified P check algorithm related to the node address, which can ensure that when one node transmits data, other nodes do not transmit, avoiding the problem of data collision.

The utility model is a system with one master and multiple slaves, including a lower computer system composed of storage batteries and an upper computer system composed of a master control station. The wireless module adopts the RF frequency point of ISM (Industrial, Scientific and Medical) specified by ITU (International Telecommunication Union). The wireless transmission module used complies with European ETSI (EN300-220-1 and EN301-439-3) and FCC15.247/15.249 certification specifications, meets wireless regulatory requirements, and does not need to apply for a frequency use license. The module adopts a high-performance base frequency crystal oscillator, which meets the requirements of the industrial environment. The wireless communication part is based on the FSK/GFSK modulation mode, and the actual bit error rate is 10 ^-5 ~ 10 ^-6 .

A reasonable communication method can not only ensure the reliability, speed and efficiency of data communication, but also reduce the power consumption of nodes and prolong the use time of nodes under the premise of ensuring communication.

Claims (3)

1. The intelligent storage battery status wireless monitoring device for the substation DC screen is composed of a data acquisition part and a wireless communication part, wherein the data acquisition part is composed of a data acquisition module, a current sensor, a signal acquisition circuit, and a DSP digital signal processor. It is characterized in that: The wireless communication part is composed of two parts: RF radio frequency circuit and antenna; the relationship between each part is: each battery is connected to a data acquisition module, the batteries are connected in series to form a battery pack, and the data acquisition module of one of the batteries in each battery pack The current sensor is added in the middle, the data acquisition module and the current sensor are respectively connected with the signal acquisition circuit, the signal acquisition circuit is connected with the DSP digital signal processor, and the DSP digital signal processor is connected with the RF radio frequency circuit, and the RF radio frequency circuit sends the data to the main control station through the antenna . 2. The intelligent battery status wireless monitoring device for substation DC panels according to claim 1, characterized in that: the data acquisition module integrates a voltage sensor, adopts a compact design, and is installed at the nearest monitoring point of each battery. 3. The wireless monitoring device for intelligent storage battery status for substation DC panels as claimed in claim 1, characterized in that: the wireless communication part adopts a standard 10cm antenna, and the antenna is fixed on the RF radio frequency circuit.

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