CN104852381B - Portable shelter monitoring system and battery energy storage system charge/discharge control method - Google Patents

Abstract

The invention discloses a mobile shelter monitoring system and a charging and discharging control method for a battery energy storage system. The system controls the on-load tap-changer of the line voltage regulator by monitoring the bus voltage on the output side, thereby changing the transformation ratio of the autotransformer to realize the line on-load automatic voltage regulation and increase the terminal voltage of the distribution network. At the same time, the system monitors the state of battery energy storage, controls the battery energy storage system to discharge at peak loads and charge at low loads, and coordinates the energy consumption of the energy storage bidirectional converter and the battery energy storage system. On the one hand, it ensures the battery energy storage system The safe, stable and reliable operation of the system improves the efficiency of the battery energy storage system on the other hand. The monitoring system realizes the joint control of the line voltage regulator and the battery energy storage system, fully utilizes the advantages of the battery energy storage system, expands the working range of the line voltage regulator, and effectively solves the problem of low voltage at the end of the distribution network. The problem.

Description

Mobile shelter monitoring system and battery energy storage system charging and discharging control method

technical field

The present invention relates to the technical field of a voltage control device or method, in particular to a mobile shelter monitoring system and a charging and discharging control method for a battery energy storage system.

Background technique

In recent years, with the rapid development of my country's economy, higher and higher requirements have been put forward for the power supply capacity and power supply quality of the distribution network. However, due to the long power supply radius of some distribution network lines, under heavy load conditions, the line voltage is too low, which makes it difficult to meet the requirements of power supply quality.

Traditional distribution network transformation measures mainly include upgrading or building new substation transformers, transmission and distribution lines, etc. However, the cost of distribution network transformation is relatively high. In the case of large load peak-valley differences, it is easy to cause low utilization of power resources and low grid investment. low efficiency issues.

To solve the problem of unqualified line voltage, the patent document of Chinese Patent No. 201420134372.9 discloses an automatic voltage regulator for distribution lines, but the voltage regulation range of this voltage regulator is limited, and the maximum voltage regulation range is 30% Un. In the case of severe low voltage, the effect of voltage boost is limited. The patent document of Chinese Patent No. 201410562452.9 discloses a mobile battery energy storage system of lithium iron phosphate battery and its control method, but its essence is only a battery energy storage system, which cannot fundamentally solve the problem of low voltage at the end of the distribution network. question.

Contents of the invention

The technical problem to be solved by the present invention is to provide a mobile shelter monitoring system and a battery energy storage system charging and discharging control method. Voltage regulator and battery energy storage system, thereby expanding the working range of the line voltage regulator, effectively solving the problem of low voltage at the end of the distribution network.

In order to solve the above technical problems, the technical solution adopted by the present invention is: a mobile shelter monitoring system, characterized in that: the monitoring system includes a central processing unit, a human-computer interaction module, an analog acquisition board, and a GPRS communication module , power supply module, voltage acquisition module and current acquisition module, the central processing unit conducts two-way communication with the human-computer interaction module, analog quantity acquisition board, frequency converter, GPRS communication module, voltage regulator controller through the serial communication interface, and through the Ethernet The network interface communicates with the PCS (Power Conversion System), and the central processing unit collects the three-phase voltage and three-phase current of the bus on the power supply side and the output side through the voltage acquisition module and the current acquisition module, and compares them with the reference voltage. Control the on-load tap changer of the line voltage regulator to realize on-load automatic voltage regulation and control the battery energy storage system to perform charging and discharging operations.

The further technical solution is: the analog acquisition board and the positive and negative inverters of the battery energy storage system communicate with the central processing unit through the serial port, and the analog acquisition board is used to collect the flow, pressure, temperature and potential information of the battery energy storage system , and control the start, stop and frequency conversion operation of the electrolyte circulating pump through the frequency converter.

A further technical solution is: the PCS communicates with the central processing unit through Ethernet, controls the charging and discharging operation of the PCS according to the charging and discharging control strategy of the battery energy storage system, and coordinates the operation energy consumption of the PCS and the battery energy storage system.

A further technical solution is: the human-computer interaction module communicates with the central processing unit through the serial port, and the human-computer interaction module is used to provide a friendly human-computer interaction interface for the monitoring system.

The further technical solution is: the GPRS communication module communicates with the central processing unit through the serial port, and the GPRS communication module communicates with the remote background through the wireless network, which is used to send the operating status of the line voltage regulator and the battery energy storage system and run information.

A further technical solution is: the input terminal voltage of the power module is AC or DC 220V, and the output voltage is +5V, +12V, -12V and/or +24V.

A further technical solution is: the monitoring system also includes a debugging port for two-way data communication with the central processing unit through an Ethernet interface.

A further technical solution is: the human-computer interaction module is a touch screen.

The present invention also discloses a charging and discharging control method for a battery energy storage system, which is characterized in that the method includes the following steps:

1) The monitoring system monitors the three-phase voltage U of the busbar on the output side through the voltage acquisition module. When the three-phase voltage U<Umin (Minimum Voltage, Minimum Voltage), the battery energy storage system discharges and runs. In the energy storage SOC (state of charge, When the State of Charge) is low, limit its discharge power until the battery energy storage system SOC<SOCmin (Minimum State of Charge, Minimum State of Charge) and stop discharging; when the three-phase voltage U>Umin, the battery energy storage system is charging and running, Limit the charging power of the battery energy storage system when the SOC is high, and stop charging until the battery energy storage system SOC>SOCmax (Maximum State of Charge);

2) When the battery energy storage system is charging and running, the charging power command value is increased step by step. When the charging power limit is reached, the battery energy storage system is charged according to the maximum charging power to ensure that the SOC of the battery energy storage system is running at a high level;

3) When the battery energy storage system is in discharge operation, the discharge power command value shall be increased step by step to meet the power demand of the load as much as possible. When the discharge power limit is reached, the power demand of the load is still not met. Discharge according to the maximum discharge power.

The beneficial effect of adopting the above technical solution is that the monitoring system realizes the combined control of the line voltage regulator and the battery energy storage system, fully utilizes the advantages of the battery energy storage system, and expands the working range of the line voltage regulator. Effectively solve the problem of low voltage at the end of the distribution network. The method can control the discharge of the battery energy storage system at peak loads and charge at low loads, and coordinate the energy consumption of the energy storage bidirectional converter and the battery energy storage system. On the one hand, it ensures the safety, stability and efficiency of the battery energy storage system. Reliable operation, on the other hand, improves the efficiency of the battery energy storage system.

Description of drawings

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is the functional block diagram of monitoring system of the present invention;

Figure 2 is a schematic diagram of the installation positions of PT (voltage transformer, Voltage transformer) and CT (current transformer, Current transformer) on the line voltage regulator;

Fig. 3 is a flow chart of the charging and discharging control method of the battery energy storage system in the present invention;

Among them: 1-power supply side, 2-output side, 3-line voltage regulator, 4-battery energy storage system, 5-load.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the following description, a lot of specific details are set forth in order to fully understand the present invention, but the present invention can also be implemented in other ways different from those described here, and those skilled in the art can do it without departing from the meaning of the present invention. By analogy, the present invention is therefore not limited to the specific examples disclosed below.

As shown in Figure 1, the present invention discloses a mobile shelter monitoring system, the monitoring system includes a central processing unit, a human-computer interaction module, an analog acquisition board, a GPRS communication module, a power supply module, a voltage acquisition module and a current Acquisition module, the central processor conducts two-way communication with the human-computer interaction module, analog acquisition board, frequency converter, GPRS communication module, and voltage regulator controller through the serial communication interface, and communicates with the PCS through the Ethernet interface. The three-phase voltage and three-phase current of the bus on the power supply side and the output side are respectively collected by the voltage acquisition module and the current acquisition module, compared with the reference voltage, and the on-load tap-changer of the line voltage regulator is controlled to realize on-load automatic voltage regulation and control The battery energy storage system performs charging and discharging operations.

The voltage conversion module converts 100V or 57.73V output from the secondary side of the PT into a 5V voltage signal; the current conversion module converts 5A or 1A output from the secondary side of the CT into a 5V voltage signal.

The central processor communicates with the touch screen through the serial communication interface COM0, and the touch screen displays the three-phase voltage, three-phase current, battery voltage, battery current, operating parameters of the battery energy storage system, system alarm information and event records on the power supply side and output side bus At the same time, it can start, stop and frequency conversion the electrolyte circulation pump of the battery energy storage system.

The central processing unit communicates with the analog acquisition board through the serial communication interface COM1, and the analog acquisition board collects various non-electrical parameters such as flow, pressure, temperature, and potential of the battery energy storage system.

The central processing unit communicates with the battery energy storage positive and negative inverters through the serial communication interfaces COM2 and COM3 to control the start, stop and frequency conversion of the electrolyte circulation pump of the battery energy storage system.

The central processor communicates with the remote background through the serial communication interface COM4 and the GPRS module, and provides operation and maintenance personnel with the operating status and operating information of the line voltage regulator and battery energy storage system in the mobile shelter.

The central processing unit communicates with the line voltage regulator controller through the serial communication interface COM5, and compares it with the reference voltage by collecting the three-phase voltage of the bus on the output side. When the voltage on the output side is greater than (or less than) the reference value and exceeds the allowable range , control the on-load tap changer to issue a downshift (or upshift) command, thereby changing the transformation ratio of the autotransformer to realize automatic voltage regulation on load.

The central processing unit communicates with the PCS through the Ethernet NET0, and controls the charging and discharging operation of the PCS according to the three-phase voltage of the bus on the output side, and the Ethernet NET1 is the debugging interface of the monitoring device.

The central processor provides two control outputs to start or stop the heating and cooling system to ensure that the battery energy storage system operates under the best environmental conditions.

The power supply module adopts standard AC or DC 220V input to provide +5V, +12V, -12V, +24V power supply voltage for the monitoring system.

As shown in Figure 2, the line voltage regulator 3 monitored by the monitoring system in the present invention is connected in series between the power supply side 1 and the output side 2 bus bars, the battery energy storage system 4 is connected in parallel on the load side, and the battery energy storage system 4 power And the system capacity is determined according to the capacity of the connected load. The PT collects the three-phase voltage of the power supply side 1 and the output side 2 bus, and the CT collects the three-phase current before the access point of the battery energy storage system 4 and behind the output side 2 bus.

As shown in Figure 3, the present invention also discloses a charging and discharging control method for a battery energy storage system, which is characterized in that the method includes the following steps:

1) The monitoring system monitors the three-phase voltage U of the bus on the output side through the voltage acquisition module. When the three-phase voltage U<Umin, the battery energy storage system discharges and operates, and when the energy storage SOC is low, its discharge power is limited until the battery energy storage Stop discharging when the system SOC<SOCmin; when the three-phase voltage U>Umin, the battery energy storage system charges and runs, and limits its charging power when the battery energy storage system SOC is high, and stops charging until the battery energy storage system SOC>SOCmax;

2) When the battery energy storage system is charging and running, the charging power command value is increased step by step. When the charging power limit is reached, the battery energy storage system is charged according to the maximum charging power to ensure that the SOC of the battery energy storage system is running at a high level;

3) When the battery energy storage system is in discharge operation, the discharge power command value shall be increased step by step to meet the power demand of the load as much as possible. When the discharge power limit is reached, the power demand of the load is still not met. Discharge according to the maximum discharge power.

Claims (9)

1. a kind of portable shelter monitoring system, it is characterised in that：The monitoring system includes central processing unit, man-machine interaction mould Block, analog acquisition plate, GPRS communication modules, power module, voltage acquisition module and current acquisition module, central processing unit lead to Serial communication interface is crossed with human-computer interaction module, analog acquisition plate, frequency converter, GPRS communication modules, regulator controller to enter Row two-way communication, and communicated by Ethernet interface with PCS, central processing unit passes through voltage acquisition module and current acquisition module The three-phase voltage and three-phase current of collection mains side and output side bus, are compared with reference voltage respectively, and control circuit is adjusted The load ratio bridging switch of depressor realizes loaded automatic voltage-regulating and controls battery energy storage system progress charge and discharge electrically operated.

2. portable shelter monitoring system according to claim 1, it is characterised in that：Analog acquisition plate and battery storage The positive and negative electrode frequency converter of energy system is communicated with central processing unit by serial ports, and analog acquisition plate is used to gather battery storage Flow, pressure, temperature, the electrical potential information of energy system, and pass through the startup of Frequency Converter Control electrolyte circulating pump, stop and become Frequency is operated.

3. portable shelter monitoring system according to claim 1, it is characterised in that：PCS passes through Ethernet and centre Device communication is managed, is run according to the charge and discharge control policy control PCS of battery energy storage system discharge and recharge, coordinates PCS and battery storage The operation energy consumption of energy system.

4. portable shelter monitoring system according to claim 1, it is characterised in that：Human-computer interaction module by serial ports with Central processing unit is communicated, and human-computer interaction module is used for the human-computer interaction interface that close friend is provided for monitoring system.

5. portable shelter monitoring system according to claim 1, it is characterised in that：GPRS communication modules are handled with center Device is communicated by serial ports, and GPRS communication modules are communicated with distant place backstage by wireless network, for for operation maintenance personnel The running status and operation information of transmitting line pressure regulator and battery energy storage system.

6. portable shelter monitoring system according to claim 1, it is characterised in that：The input electricity of the power module Press for exchange or direct current 220V, be output as+5V ,+12V, -12V and/or+24V.

7. portable shelter monitoring system according to claim 1, it is characterised in that：The monitoring system also includes passing through The debugging mouth of Ethernet interface and central processing unit bidirectional data communication.

8. portable shelter monitoring system according to claim 1, it is characterised in that：The human-computer interaction module is touch Screen.

9. a kind of battery energy storage system charge/discharge control method, it is characterised in that methods described comprises the following steps：

1）Monitoring system monitors the three-phase voltage U of the output side bus of power distribution network by voltage acquisition module, as three-phase voltage U< During Umin, battery energy storage system electric discharge operation limits its discharge power when energy storage SOC is relatively low, until battery energy storage system SOC <Stop electric discharge during SOCmin；As three-phase voltage U>During Umin, battery energy storage system charge operation, battery energy storage system SOC compared with Its charge power is limited when high, until battery energy storage system SOC>Stop charging during SOCmax；

2）During battery energy storage system charge operation, increase charge power command value, when reaching charge power limit value, battery step by step Energy-storage system is charged according to maximum charge power, it is ensured that battery energy storage system SOC is in run at high level；

3）During battery energy storage system electric discharge operation, increase discharge power command value step by step, the power need of load should be met as far as possible Ask, when reaching discharge power limit value, still can not meet the power demand of load, now battery energy storage system is put according to maximum Electrical power is discharged.