CN115864653A - On-line nuclear capacity system and method for remote inverter feed-in battery pack - Google Patents

Abstract

The invention relates to an on-line capacity checking system and method for a remote inverter feed-in battery pack. The system includes: an online monitoring unit, which is used to monitor and upload the operating parameters of the battery pack; an inverter unit, which is used to invert DC power into AC power and feed it back to the grid under the control of the inverter control signal; a remote discharge control unit , used to control and feed back the connection status between the battery pack, the charging bus, and the inverter unit based on the remote control signal; the display and control unit, used to set the discharge core capacity parameters, obtain and display the battery pack uploaded by the online monitoring unit Operating parameters, sending a remote control signal to the remote discharge control unit, obtaining the connection status fed back by the remote discharge control unit, and sending an inverter control signal to the inverter unit. Method Using the above-mentioned remote inverter feed-in battery pack online capacity check system to implement the present invention can conveniently and quickly conduct check capacity tests on the battery pack, reduce manpower and material costs, and do not waste electric energy.

Description

On-line nuclear capacity system and method for remote inverter feed-in battery pack

technical field

The invention relates to an on-line capacity checking system and method for a remote inverter feed-in battery pack.

Background technique

As an important power source for DC power systems in power plants, substations and converter stations, battery packs provide uninterrupted power for relay protection, communication control, accident lighting, etc., and their power supply capacity is the final guarantee for the stable operation of plant equipment. Nuclear capacity discharge is so far recognized as the most effective means to measure the power supply capacity of batteries.

The traditional on-site nuclear capacity discharge uses manual work, which is cumbersome and consumes a lot of manpower and material resources. The current configuration of operation and maintenance personnel cannot meet the operation and maintenance requirements stipulated in the regulations. At the same time, the traditional discharge technology puts the battery pack in an offline state, which cannot protect the substation power loss of a single pack of batteries; and the traditional discharge of the battery pack is carried out in the form of heat consumption, resulting in high ambient temperature and load resistance heating. In the case of red, the grid power is wasted.

Contents of the invention

The purpose of the present invention is to provide an on-line capacity verification system and method for remote inverter-fed battery packs that can replace manual work, realize remote inverter discharge nuclear capacity operation, is convenient and quick, and avoids waste of electric energy.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A remote reversible feed-in battery pack online capacity checking system is used for online capacity checking of the battery pack, which includes:

an online monitoring unit, the online monitoring unit is used to monitor and upload the operating parameters of the battery pack;

An inverter unit, the inverter unit is used to invert the direct current into alternating current under the control of the inverter control signal and feed it back to the power grid;

A remote discharge control unit, the remote discharge control unit is used to control the connection state between the battery pack, the charging bus and the inverter unit based on the remote control signal and feed back the connection state;

A display and control unit, the display and control unit is used to set discharge core capacity parameters, obtain and display the operating parameters of the battery pack uploaded by the online monitoring unit, send the remote control signal to the remote discharge control unit, obtain The remote discharge control unit feeds back the connection status, and sends the inverter control signal to the inverter unit.

The display control unit is respectively connected to the online monitoring unit and the inverter unit through a communication bus, and the display control unit is connected to the remote discharge control unit through a signal line.

The communication bus is RS485 bus.

The remote discharge control unit includes a main control switch and a contactor controlled by the remote control signal, the main control switch is connected between the switching power supply and the coil of the contactor, and the normally closed contact of the contactor is connected Between the charging bus and the battery pack, the normally open contact of the contactor is connected between the battery pack and the inverter unit.

The remote discharge control unit further includes a protection diode connected in parallel across the normally closed contact of the contactor.

An on-line capacity checking method for a remote reversible grid-feed battery pack is implemented by using the aforementioned online capacity check system for a remote invertible grid-feed battery pack, which includes the following steps:

Step 1: when it is necessary to perform checking discharge on the battery pack, use the display and control unit to set the discharge core capacity parameters;

Step 2: The display and control unit sends the remote control signal for starting discharge to the remote discharge control unit, and the remote control unit controls the battery pack to disconnect from the charging bus and controls the battery The group establishes a connection with the inverter unit, and feeds back the connection status to the display and control unit; the display and control unit sends the inverter control signal for starting the inverter to the inverter unit , the inverter unit inverts the direct current into alternating current and feeds it back to the power grid; the online monitoring unit monitors the operating parameters of the battery pack and uploads them to the display and control unit;

Step 3: When the discharge end condition is met, the display and control unit sends the inverter control signal for stopping the inverter to the inverter unit, and the inverter unit stops converting the direct current into alternating current and Feedback to the grid;

Step 4: The display and control unit sends the remote control signal for stopping the discharge to the remote discharge control unit, and the remote discharge control unit controls the battery pack to disconnect from the inverter unit and controls The battery pack is connected to the charging bus, and the connection status is fed back to the display and control unit.

In the step 1, the discharge core capacity parameters include the lower limit of the group terminal voltage of the battery pack, the lower limit of the cell voltage of the battery pack, the discharge duration threshold, and the discharge current value.

In the step 2, the online monitoring unit monitors the real-time group terminal voltage value of the battery pack, the real-time cell voltage value of the battery pack, and the discharge current of the battery pack in real time.

In the step 3, the discharge end condition includes: the real-time pack terminal voltage value of the battery pack drops to the lower limit of the pack terminal voltage of the battery pack, and the real-time cell voltage value of the battery pack drops to the lower limit of the battery pack terminal voltage. The lower limit of the monomer voltage and the discharge duration of the group reach the discharge duration threshold; when any one of the discharge point end conditions is satisfied, the display and control unit sends the inverter control signal for stopping the inverter to the inverter unit.

In the step 4, after the connection between the battery pack and the charging bus is established, the battery pack is charged until it enters a floating charging state, and the charging and discharging of the battery pack is completed.

Due to the application of the above-mentioned technical solutions, the present invention has the following advantages compared with the prior art: the present invention can conveniently and quickly perform nuclear capacity testing on the battery pack, reduce manpower and material costs, and do not waste electric energy.

Description of drawings

Accompanying drawing 1 is the schematic diagram of the on-line nuclear capacity system of the remote inverter feed-in battery pack of the present invention.

Detailed ways

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

Embodiment 1: As shown in Fig. 1 , an on-line nuclear capacity system for a reversible grid-feed battery pack includes an on-line monitoring unit, an inverter unit, a remote discharge control unit, and a display and control unit.

The online monitoring unit is connected with the battery pack, and is used for monitoring and uploading the operating parameters of the battery pack. The inverter unit is used to invert the direct current into alternating current under the control of the inverter control signal and feed it back to the grid. The remote discharge control unit is arranged between the battery pack, the inverter unit, and the charging bus, and is used to control the connection state between the battery pack, the charging bus, and the inverter unit based on the remote control signal and to feed back the connection state. The display and control unit is respectively connected with the online monitoring unit, the inverter unit, and the remote discharge control unit, and is used to set the discharge core capacity parameters, obtain and display the operating parameters of the battery pack uploaded by the online monitoring unit, and send remote control signals to the remote discharge control unit. The control unit obtains the connection status fed back by the remote discharge control unit, and sends an inverter control signal to the inverter unit. The display and control unit can communicate with the online monitoring unit and the inverter unit through a communication bus (such as RS485 bus), and the display and control unit is connected with the remote discharge control unit through a signal line.

The remote discharge control unit includes a main control switch K and a contactor controlled by a remote control signal. The main control switch K is connected between the switching power supply (DC 110/220V input) and the coil of the contactor, and the normally closed contact of the contactor is connected to Between the positive pole HM+ of the charging bus and the positive pole of the battery pack, the normally open contact of the contactor is connected between the battery pack and the inverter unit to form a discharge switch, and between the negative pole of the battery pack and the negative pole HM- of the charging bus. Both the positive pole HM+ and the negative pole HM- of the charging bus are equipped with a fuse FUSE. The remote discharge control unit also includes a protection diode connected in antiparallel across the normally closed contact of the contactor.

The above-mentioned online capacity checking system for the remote inverter feed-in battery pack is used for online capacity check of the battery pack, and the online capacity check method for the remote inverter feed-in battery pack implemented by it includes the following steps:

Step 1: When it is necessary to carry out checking discharge on the battery pack, use the display and control unit to set the discharge core capacity parameters.

In this step, the discharge core capacity parameters include the lower limit of the terminal voltage of the battery pack, the lower limit of the individual voltage of the battery pack, the discharge time threshold (generally 10 hours), the discharge current value (generally 0.1C ₁₀ check discharge, test battery actual capacity of the group).

Step 2: The display and control unit sends a remote control signal for starting discharge to the remote discharge control unit. The remote control unit controls the battery pack to disconnect from the charging bus, controls the battery pack to establish a connection with the inverter unit, and feeds back the connection status to the display and control unit; the display and control unit sends an inverter control signal for starting the inverter to the inverter unit, and the inverter unit inverts the direct current into alternating current and feeds it back to the grid; the online monitoring unit monitors the operating parameters of the battery pack Monitor and upload to the display and control unit.

In this step, the discharge command is started. After starting, the display and control unit judges the state of the battery pack, and the display and control unit sends a remote control signal for starting discharge to the remote discharge control unit. After receiving the signal, the normally closed switch inside the remote discharge control unit The contactor is disconnected, and the battery pack is withdrawn from the bus charging circuit (at the same time, the one-way conductivity of the protection diode is used to realize the protection of AC power loss, and the real-time online function of the battery pack is realized). After the normally closed contactor is disconnected, the state will be fed back to the display and control unit, and the display and control unit will send the discharge current and the inverter control signal to start the inverter to the inverter unit. The inverter unit uses DC constant current input and three-phase AC feed back into the grid. The online monitoring unit monitors the real-time group terminal voltage value of the storage battery group, the real-time monomer voltage value of the storage battery group, the discharge current of the storage battery group in real time, and can also monitor the temperature. These operating parameters uploaded to the display and control unit are recorded by the display and control unit, and support record viewing and data export.

Step 3: When the discharge end condition is satisfied, the display and control unit sends an inverter control signal for stopping the inverter to the inverter unit, and the inverter unit stops converting the direct current into alternating current and feeds it back to the grid.

In this step, the discharge end conditions include: the real-time group terminal voltage value of the battery pack drops to the lower limit of the battery pack terminal voltage, the real-time cell voltage value of the battery pack drops to the lower limit of the cell voltage of the battery pack, and the discharge duration reaches the discharge duration Threshold; when any one of the discharge end conditions is met, the display control unit sends an inverter control signal for stopping the inverter to the inverter unit.

Step 4: The display and control unit sends a remote control signal for stopping the discharge to the remote discharge control unit. The remote discharge control unit controls the battery pack to disconnect from the inverter unit, controls the battery pack to establish a connection with the charging bus, and displays the connection status Feedback to the display and control unit.

In this step, the display control unit sends a remote control signal for stopping the discharge to the remote discharge control unit, closes the contactor, and feeds back the state of the contactor to the display control unit after closing. After the battery pack is connected to the charging bus, the battery pack is put into the charging circuit again, and the battery pack is charged until it enters the floating charging state, and the charging and discharging of the battery pack is completed.

Under the premise of ensuring the safety of the DC system, the above scheme remotely starts to discharge the battery pack online, detects the actual capacity and state of the battery pack, monitors the voltage status of the battery pack in real time, and periodically activates the battery pack. The AC voltage that meets the requirements is output through the DC/AC inverter, fed back to the grid, and consumed by the actual load in the grid. After the system is started, the traditional manual work is replaced by remote charging and discharging technology, and the remote inverter discharge nuclear capacity operation reduces the cost of manpower and material resources. For the normal power supply of the DC system, during the discharge process, if the voltage of the charger suddenly drops, the system stops discharging instantly and without time difference and switches to the battery pack to supply the DC system load normally. Practical application shows that this technology greatly reduces the workload of DC system detection and maintenance, improves the service life of batteries, reduces production and maintenance costs, and the way of inverter discharge feed-in grid does not generate any heat. The calculation of nuclear capacity is accurate and simple, and the power feedback Electricity, no waste of grid electricity, in line with national energy conservation and emission reduction requirements.

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and not to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims (10)

1. An online capacity checking system for a remote inverter feed-in battery pack, which is used for online capacity checking of a battery pack, characterized in that it includes: an online monitoring unit, the online monitoring unit is used to monitor and upload the operating parameters of the battery pack; An inverter unit, the inverter unit is used to invert the direct current into alternating current under the control of the inverter control signal and feed it back to the power grid; A remote discharge control unit, the remote discharge control unit is used to control the connection state between the battery pack, the charging bus and the inverter unit based on the remote control signal and feed back the connection state; A display and control unit, the display and control unit is used to set discharge core capacity parameters, obtain and display the operating parameters of the battery pack uploaded by the online monitoring unit, send the remote control signal to the remote discharge control unit, obtain The remote discharge control unit feeds back the connection status, and sends the inverter control signal to the inverter unit. 2. The online nuclear capacity system of remote inverter feed-grid battery pack according to claim 1, characterized in that: the display and control unit communicates with the online monitoring unit and the inverter unit respectively through a communication bus connected, the display control unit is connected with the remote discharge control unit through a signal line. 3. The on-line nuclear capacity system for remote invertible feed-in battery packs according to claim 2, characterized in that: the communication bus is an RS485 bus. 4. The remote reversible grid-feed battery pack online nuclear capacity system according to claim 1, characterized in that: the remote discharge control unit includes a main control switch and a contactor controlled by the remote control signal, so The main control switch is connected between the switching power supply and the coil of the contactor, the normally closed contact of the contactor is connected between the charging bus and the battery pack, and the normally open contact of the contactor is connected to Between the battery pack and the inverter unit. 5 . The remote reversible on-line nuclear capacity system for feed-in battery packs according to claim 4 , wherein the remote discharge control unit further includes protection diodes connected in parallel at both ends of the normally closed contact of the contactor. 5 . 6. An online capacity checking method for a remote reversible grid-fed battery pack, which is implemented by using the online capacity check system for a remotely reversible grid-fed battery pack as claimed in any one of claims 1 to 5, characterized in that : It includes the following steps: Step 1: when it is necessary to perform checking discharge on the battery pack, use the display and control unit to set the discharge core capacity parameters; Step 2: The display and control unit sends the remote control signal for starting discharge to the remote discharge control unit, and the remote control unit controls the battery pack to disconnect from the charging bus and controls the battery The group establishes a connection with the inverter unit, and feeds back the connection status to the display and control unit; the display and control unit sends the inverter control signal for starting the inverter to the inverter unit , the inverter unit inverts the direct current into alternating current and feeds it back to the power grid; the online monitoring unit monitors the operating parameters of the battery pack and uploads them to the display and control unit; Step 3: When the discharge end condition is met, the display and control unit sends the inverter control signal for stopping the inverter to the inverter unit, and the inverter unit stops converting the direct current into alternating current and Feedback to the grid; Step 4: The display and control unit sends the remote control signal for stopping the discharge to the remote discharge control unit, and the remote discharge control unit controls the battery pack to disconnect from the inverter unit and controls The battery pack is connected to the charging bus, and the connection status is fed back to the display and control unit. 7. The method for online capacity checking of remote inverter-fed grid-type battery packs according to claim 6, characterized in that: in the step 1, the discharge nuclear capacity parameters include the lower limit of the terminal voltage of the battery pack, The lower limit of the cell voltage, the discharge duration threshold, and the discharge current value of the battery pack. 8. The method for online capacity verification of a remote inverter feed-in battery pack according to claim 7, characterized in that: in the step 2, the online monitoring unit monitors the real-time group terminal voltage value of the battery pack in real time , the real-time monomer voltage value of the battery pack, and the discharge current of the battery pack are monitored. 9. The online capacity verification method for a remote inverter-fed grid battery pack according to claim 8, characterized in that in step 3, the discharge end condition includes: the real-time pack terminal voltage value of the battery pack drop to the lower limit of the group terminal voltage of the battery pack, the real-time cell voltage value of the battery pack drops to the lower limit of the cell voltage of the battery pack, and the discharge duration reaches the discharge duration threshold; when any one of the When the end condition is set, the display and control unit sends the inverter control signal for stopping the inverter to the inverter unit. 10. The method for on-line capacity verification of a remote inverter feed-in battery pack according to claim 5, characterized in that: in step 4, after the battery pack is connected to the charging bus, the battery pack Charging until it enters the floating charging state, and the charging and discharging of the battery pack is completed.

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