CN117411117A

CN117411117A - DC power supply module and system, operation and maintenance control method of system and intelligent control platform

Info

Publication number: CN117411117A
Application number: CN202311251866.5A
Authority: CN
Inventors: 杜旭浩; 李秉宇; 庞先海; 曾四鸣; 苗俊杰; 赵俊蕾; 蔡子文; 刘杰
Original assignee: State Grid Corp of China SGCC; Electric Power Research Institute of State Grid Hebei Electric Power Co Ltd
Current assignee: State Grid Corp of China SGCC; Electric Power Research Institute of State Grid Hebei Electric Power Co Ltd
Priority date: 2023-09-26
Filing date: 2023-09-26
Publication date: 2024-01-16

Abstract

The invention discloses a direct current power supply module, a system and an operation and maintenance control method of the system and an intelligent control platform, wherein each power supply module is a miniature direct current power supply and comprises a charging module, a 220V storage battery pack, management protection and the like, and N+1 charging and storing integrated power supply modules form a novel modularized direct current power supply system. The invention can effectively reduce the risk of direct current bus voltage loss caused by faults such as open circuit, failure and the like of the whole group of batteries separated from the bus or individual backward batteries in the conventional direct current power supply system, and improves the running reliability of the direct current power supply system.

Description

DC power supply module and system, operation and maintenance control method of system and intelligent control platform

Technical Field

The invention belongs to the technical field of direct current power supplies, and relates to a direct current power supply module, a direct current power supply system, a system operation and maintenance control method and an intelligent management and control platform.

Background

The station DC power supply mainly provides DC working power supply for important loads such as control, protection, switching on/off, UPS, DC/DC communication power supply and the like in the station. The current domestic transformer substation direct current power supply system mainly comprises a charger, a storage battery pack, a direct current feeder screen, a monitoring unit and the like, wherein the charger adopts a high-frequency switch power supply charging module N+1 (less than or equal to 6) or N+2 (more than or equal to 7) to be connected in parallel for redundancy, the storage battery pack adopts a valve-controlled sealed lead-acid (VRLA) storage battery to be connected in series for group use, the direct current feeder screen generally provides 20-60 (or more) direct current feeder branches, and each feeder circuit is directly configured with components such as a direct current breaker, a Hall leakage current transformer, a power supply indicator lamp, a wiring terminal and the like.

Because the storage batteries are connected in series in groups and then connected to the direct current bus through the fuse or the breaker, the whole group of batteries are separated from the bus or the individual backward batteries in the whole group of batteries are open-circuited and fail, and the whole direct current bus is directly out of voltage when alternating current is out of power or a charger fails, so that the operation safety of a power system is seriously threatened. In order to solve the problem, the following three technical schemes are mainly proposed at present:

1. The technical scheme of the open circuit bridging of the single battery is that diodes are reversely connected in parallel at two ends of the single battery, once the back pressure at the two ends of the open circuit of the battery exceeds the forward conducting voltage of the diodes, the diodes are immediately conducted in one direction to bypass the fault battery, and therefore the power supply continuity of a direct current bus is ensured. However, this solution has a major drawback in that the diode, once broken down, will directly short-circuit the battery, which is dangerous, and a complex protection circuit must be added to prevent the breakdown of the diode.

2. The DC bus voltage loss compensation technical scheme is characterized in that a series storage battery pack is divided into a plurality of small sections and is used as a plurality of DC/DC module inputs which are connected in parallel, all DC/DC module outputs are connected in parallel with the DC bus of the section, the output voltage of the DC/DC module is lower than the normal voltage of the DC bus, and the DC/DC module is in a hot standby state. If the section of alternating current power failure or the charging device fails, the battery pack is separated from a bus or a single battery is opened, and the like, the DC/DC module immediately provides a direct current power supply for the direct current bus, so that the voltage failure of the direct current bus can be avoided. However, the scheme has the advantages of complex structure, more equipment, higher cost, larger required space and certain limitation in practical application.

The parallel direct current power supply system of DC/DC boost type designs a single storage battery and a matched parallel power supply module into a group of parallel power supply components, and then the parallel power supply components are connected in parallel and output at the bus output end, the single battery is opened, the corresponding power supply components stop supplying power, and other parallel power supply components can continue supplying power to the direct current bus without being influenced, so that the power supply reliability of the direct current power supply is improved. However, the DC/DC boosting module in the power supply assembly has obvious current limiting characteristic, and when a short circuit fault occurs in a DC feeder line branch, the short circuit current is greatly reduced, so that the direct current breaker cannot cut off the fault in a transient mode, and the voltage of a direct current bus is greatly reduced, even a voltage loss accident is caused.

Based on the above scheme, the national network company has focused on the treatment of ac/dc hidden trouble and the improvement of reliability in recent years, but major accidents such as suburb stations in Shaanxi and Shanxi and Furui stations still occur, and the risk resisting capability and the fault diagnosis prevention and control level of the conventional dc power supply for the station need to be further improved. Meanwhile, along with the construction and popularization of a new generation of transformer substation of a national network company, development of novel direct current power supply equipment meeting the requirements of high safety and high reliability of the new generation of transformer substation is urgently needed, the risk that a direct current bus is out of voltage due to faults such as the fact that a whole group of batteries are separated from the bus or the batteries are opened and disabled after individual batteries fall in the conventional direct current power supply system is effectively reduced, and the running reliability of the direct current power supply system is improved.

Disclosure of Invention

In order to solve the defects in the prior art, the invention provides a DC power supply module, a DC power supply system, a system operation and maintenance control method and an intelligent control platform, which are used for researching the advantages and disadvantages of a conventional DC power supply and a parallel DC power supply, and based on a novel modularized DC power supply mode, the invention provides a charging and storage integrated power supply module, a novel modularized DC power supply system and an intelligent operation and maintenance control method, so that the congenital design defect of the conventional DC power supply system can be completely eradicated, the self-evaluation of the state of the DC power supply system, the autonomous diagnosis of the performance and the automatic isolation of faults can be truly realized, and the operation safety of the DC power supply system is obviously improved. The method can be popularized and applied to all newly-built substations of the power system, can upgrade and reform the original direct-current power supply system of the transformer substation, has very wide popularization and application prospects, can effectively reduce the risk of direct-current bus voltage loss caused by faults such as open circuit, failure and the like of the whole group of batteries in the conventional direct-current power supply system due to the fact that the batteries are separated from the buses or the batteries are respectively behind, and improves the running reliability of the direct-current power supply system.

The invention adopts the following technical scheme.

The utility model provides an operation and maintenance control method of DC power supply system, DC power supply system includes parallelly connected N+1 DC power supply module, the module includes charging module, storage battery branch road, BMS protection management module and electric operation switch, operation and maintenance control method is:

The BMS protection management module and the intelligent management and control platform of each module are used for monitoring and controlling the running states of the charging module, the storage battery pack and the electric operation switch of each module, so that the operation and maintenance control of the direct current power supply system is realized;

the operation and maintenance control comprises module fault handling, automatic isolation of an overheat power supply module, module battery charging, module hot standby, charging module carrying capacity testing and storage battery carrying capacity testing.

Preferably, the module fault handling, automatic isolation of the overheat power module, module battery charging, module hot standby, charging module carrying capacity test and execution priority ordering of the storage battery carrying capacity test are as follows:

the module fault handling is superior to the automatic isolation of the overheat power supply module, the automatic isolation of the overheat power supply module is superior to the charging of a module battery, the charging of the module battery is superior to the hot standby of the module, the priority of the hot standby of the module is the same as that of the charging module carrying capacity test and the storage battery carrying capacity test, and the hot standby of the module is not performed simultaneously with the charging module carrying capacity test and the storage battery carrying capacity test.

Preferably, the BMS protection management module of each module detects voltage, current and temperature data of the storage battery pack of the module, and the AC input and DC output voltage and current data of the charging module; the intelligent control platform collects the total output direct-current voltage and current data of the direct-current power supply system in real time, and the total input alternating-current voltage and current data of the direct-current power supply system; the BMS protection management module and the intelligent management and control platform of each module control the running states of the charging module, the storage battery and the electric operation switch of each module through data and instruction interaction, so that the operation and maintenance control of the direct-current power supply system is realized.

Preferably, the module failure handling comprises:

when the intelligent control platform analyzes and judges that alternating current is lost, the storage battery packs of the modules directly supply power for the direct current buses together; the method for judging the alternating current power failure is as follows:

when the alternating current input voltage and current of each module are 0, the total alternating current input voltage U of the power supply system _A 、U _B 、U _C And current I _A 、I _B 、I _C And 0, and judging that alternating current power failure occurs when the alternating current inlet switch of each power supply module and the total alternating current inlet switch J of the power supply system are in a normal closed state.

Preferably, the module failure handling comprises:

when the intelligent control platform analyzes and judges that the charging module fails, generating and sending a power generation operation switch disconnection instruction to a BMS protection management module of the failure module, and controlling the power generation operation switch of the failure module to be disconnected after the BMS protection management module receives the instruction so as to isolate the failure module; after the fault module is isolated, the intelligent control platform calculates the current load ratio F of the direct current power supply system:

1) If F is less than or equal to 0.9, other non-fault power supply modules operate in an original state;

2) If F is more than 0.9, the module in the hot standby state is restored to the normal operation state, F is calculated again, if F is less than or equal to 0.9, the operation is stopped, and if F is still more than 0.9, 3) is entered;

3) Restoring the module in the charging state to a normal running state, calculating F again, stopping operation if F is less than or equal to 0.9, and entering 4 if F is still more than 0.9);

4) Restoring the module in the overheat isolation state to a normal operation state, calculating F again, if F is less than or equal to 0.9, stopping operation, and if F is still more than 0.9, performing manual fault treatment on the tissue;

when the module in the step 2) or the step 3) does not exist, automatically skipping the corresponding step and executing the next step; when the module in the 4) does not exist, the organization manually carries out fault treatment;

the judging mode of the fault of the charging module is as follows:

when the alternating current inlet switch of each power supply module and the total alternating current inlet switch J of the power supply system are in a normal closed state, the total alternating current input voltage U of the power supply system _A 、U _B 、U _C And current I _A 、I _B 、I _C And when the state is normal, if the alternating current input voltage of the power supply module is normal and is not in the overheat state, the battery charging state, the hot standby state, the on-load test state of the charging device and the on-load test state of the storage battery, but the current output of the direct current side of the power supply module is 0, and the input and the output of other modules are normal, the fault of the charging module of the power supply module is judged.

Preferably, the module failure handling comprises:

when the intelligent control platform analyzes and judges that the output between the power supply modules is unbalanced, an output unbalance alarm between the power supply modules is sent out, the intelligent control platform communicates with a charging module of the power supply module with the largest direct current output, issues a command to the charging module, adjusts the direct current output voltage of the charging module downwards, calculates the current flow balancing unbalance degree between the direct current outputs of all the power supply modules in the normal running state in real time, stops adjusting the voltage until the current flow balancing unbalance degree is lower than +/-5%, and releases the alarm;

The output imbalance among the power supply modules is judged in the following ways:

when the current sharing unbalance degree among the direct current outputs of all the power supply modules in the normal running state is more than or equal to +/-5%, the output unbalance among the power supply modules is judged; the normal operation state refers to a state of no overheat isolation, battery charging, hot standby, charging module load test and storage battery load test tube control;

the calculation formula of the current sharing unbalance degree D is as follows:

wherein I is _i The current value is output by the power supply module i;

I _{total (S)} The current is output to the direct current power supply system in total real time;

I _N rated output current of the charging module for a single power supply module;

X _{failure of} The number of power supply modules which are stopped by faults;

X _superheating The number of power supply modules which are in overheat shutdown;

X _{charging method} The number of the power supply modules in a state of charging the storage battery pack;

X _{hot standby} The number of power modules in the hot standby state.

Preferably, the module failure handling comprises:

the intelligent control platform analyzes and judges that the abnormal fault of the switch state occurs, sends out an abnormal alarm of the switch state, and carries out manual maintenance treatment; the judgment mode of the abnormal fault of the switch state is as follows:

besides the manual disconnection of the fault maintenance, when the running states of the alternating current inlet switch, the total alternating current inlet switch J of the power supply system and the total direct current output switch of each module are in a disconnection state, the abnormal fault of the switch state is judged.

Preferably, the automatic isolation of the overheat power supply module is specifically:

BMS protects management module monitoring each battery positive negative pole post real-time temperature of this module, and when the maximum temperature of monitoring was higher than the fault alarm temperature who presets, send overheated isolation application to intelligent management and control platform, after the intelligent management and control platform received the application, calculate the overheated DC power supply system load ratio F after logging out of this module:

1) If F is less than or equal to 0.9, issuing an isolation-allowing instruction to a corresponding BMS protection management module, and after receiving the isolation-allowing instruction, issuing a brake-separating instruction by the BMS protection management module, controlling the electric operation switch to be opened, and enabling the module to exit from operation, wherein when the temperature of a pole of the storage battery of the module is restored to a preset normal working temperature range, the BMS protection management module issues a brake-closing instruction, and controlling the electric operation switch to be closed;

2) If F is more than 0.9, firstly, restoring the module in the hot standby state to the normal operation state, and calculating F again, if F is less than or equal to 0.9, performing the operation of 1), and if F is still more than 0.9, entering 3);

3) Restoring the module in the charging state to a normal running state, calculating F again, if F is less than or equal to 0.9, performing the operation of 1), and if F is still more than 0.9, entering 4);

4) Sending a temporary isolation instruction to the BMS protection management module, continuing running the corresponding module, and after the failure module is recovered to be normal, calculating F which is less than or equal to 0.9 in real time, and then performing the operation of 1);

when the module in the step 2) or the step 3) does not exist, automatically skipping the corresponding step and executing the next step; and 4) when the modules in the step 4) do not exist, the capacity of the direct current power supply system is expanded by considering the number of the increased modules.

Preferably, the module battery charging specifically includes:

when the BMS protection management module monitors that the voltage value of each power module storage battery pack reaches or is lower than a preset value, an application requesting charging is sent to the intelligent management and control platform, and after the intelligent management and control platform receives the application, the load ratio F of the direct current power supply system after the corresponding module charging exits is calculated:

1) If F is less than or equal to 0.9, sending a charge allowing instruction to the BMS protection management module, sending a brake opening instruction to the BMS protection management module after receiving the charge allowing instruction, controlling the electric operation switch to be opened, sending a closing instruction to the BMS protection management module, controlling the charging contactor M in the BMS protection management module to be closed, charging the storage battery pack, and after the voltage value of the storage battery pack reaches a set cut-off voltage, sending a breaking instruction to the BMS protection management module, controlling the charging contactor M to be opened, stopping charging the storage battery pack, sending a brake closing instruction to the BMS protection management module, controlling the electric operation switch to be closed, and recovering the module to be in a normal power supply state of a direct current load; when the cut-off voltage is not reached in the charging process of the storage battery, if an instruction for recovering to a normal running state of the intelligent control platform is received, the instruction of the intelligent control platform is preferentially executed, the charging is stopped, and the normal power supply state is recovered;

2) If F is more than 0.9, the module in the hot standby state is restored to the normal running state, F is calculated again, if F is less than or equal to 0.9, the operation of 1) is carried out, and if F is still more than 0.9, the operation of 3) is carried out;

3) Sending a charge suspending instruction to the BMS protection management module, continuing to operate the corresponding module, and after waiting for the failure module to recover to a normal operation state or the overheat isolation module to recover to the normal operation state, calculating F less than or equal to 0.9 in real time, and then performing the operation of 1);

automatically skipping 2) when the module in the 2) does not exist, and executing 3); and 3) when the modules in the step 3) do not exist, the capacity of the direct current power supply system is expanded by considering the number of the increased modules.

Preferably, the hot standby of the module is specifically:

executing a hot standby strategy for a module that satisfies the following conditions:

a: the maximum value of the temperatures of the positive and negative poles of each battery of the storage battery pack of the normal operation module is higher than the temperatures of the positive and negative poles of each battery of the storage battery pack of other normal operation modules, and the maximum value temperature is lower than the preset fault alarm temperature;

b: the load ratio F of the direct current power supply system after the module hot standby is withdrawn is less than or equal to 0.9;

the hot standby strategy is:

a heating standby instruction is given to a module charging module executing a hot standby strategy, the output voltage of the direct current side of the module charging module is controlled to be reduced, so that the output voltage is lower than the direct current output voltage of other normally operating power modules and higher than the voltage of a storage battery pack, and then the output of the module charging module is stopped to be converted into a hot standby state;

And when the module in the hot standby state no longer meets the condition A, ending the hot standby state of the module, converting into a normal running state, and converting other modules meeting the conditions A and B into the hot standby state.

Preferably, the load ratio F is calculated as:

wherein I is _{Total (S)} The current is output to the direct current power supply system in total real time;

X _{failure of} The number of power supply modules which are stopped by faults;

X _{hot standby} The number of power modules in the hot standby state.

Preferably, the charge module load capacity test is a load capacity test of each power module charge module which is developed regularly, each module is tested in turn, and the load test is not performed when the module is in a fault, overheat or charge state;

the load capacity test process of the charging module is as follows:

the intelligent control platform issues a load capacity test instruction to the module to be tested charging module, and controls the output voltage of the direct current side of the module to be tested charging module to be raised so that the output voltage is higher than the direct current output voltage of other power supply modules which normally operate, so that the output force of the module to be tested is ensured to be maximum preferentially; the BMS protection management module monitors the output current and voltage of the module to be tested and transmits the data to the intelligent control platform, and after the test duration is over, the intelligent control platform issues a test instruction for stopping carrying capacity to the module to be tested, and controls and reduces the output voltage of the direct current side of the module to be tested to be the same as the direct current output voltage of other normal operation power supply modules;

The intelligent control platform judges the carrying capacity of the module to be tested and charges the module, when the direct current output of the module to be tested reaches the total maximum load current of the system or the rated maximum current thereof in the test process, the carrying capacity is judged to be qualified, otherwise, the carrying capacity is disqualified, and the module to be tested is manually treated in time.

Preferably, the load capacity test of the storage battery pack is a load capacity test of the storage battery pack of each power supply module which is developed regularly, and all power supply modules in a normal state are tested at the same time, and when the modules are in a fault, overheat and charging state, the load test of the storage battery pack is not performed;

the load test process of the storage battery pack comprises the following steps:

the intelligent management and control platform issues instructions to the charging modules of the power supply modules to be tested, controls and reduces the output voltage of the charging modules of the power supply modules to be tested on the direct current side, so that the output voltage is lower than the voltage of the storage battery pack and is not lower than 90% of the rated direct current bus voltage, at the moment, the charging modules of the power supply modules to be tested stop outputting, the storage battery packs of the power supply modules carry direct current loads of the system, the BMS protection management modules monitor the output current and the voltage of the storage battery packs and transmit data to the intelligent management and control platform, and after the test duration is over, the intelligent management and control platform issues instructions to the charging modules of the power supply modules to be tested, controls and increases the output voltage of the charging modules of the power supply modules to be tested to a preset normal running state value, and the power supply of the power supply modules to be tested is recovered normally;

The intelligent control platform judges the carrying capacity of the storage battery pack of the module to be tested, if the direct current of the storage battery pack of the module to be tested is not output in the testing process, or the voltage reduction speed of the storage battery pack of the module to be tested exceeds a set value, the specified testing time is not completed, the corresponding storage battery pack carrying capacity is judged to be unqualified, and the storage battery pack is manually disposed.

The direct current power supply system comprises N+1 direct current power supply modules which are connected in parallel, wherein the N power supply modules are used for completely matching the maximum design capacity of a traditional direct current power supply system charger and a storage battery pack, and the remaining 1 power supply modules are used as redundancy.

The direct-current power supply module comprises a charging module, a storage battery branch, a BMS protection management module and an electric operation switch; the charging module comprises an alternating current side and a direct current side, wherein the alternating current side is connected with alternating current input through a wire inlet breaker, and the direct current side is connected with a storage battery branch in parallel and is connected into a direct current bus through an electric operation switch;

and the BMS protection management module is used for communicating with the intelligent management and control platform, and realizing the operation and maintenance control of the direct-current power supply system through data and instruction interaction.

Preferably, the charging module is an AC/DC rectifying module, the AC side of the charging module is connected with an AC input through a circuit breaker S, and the positive and negative poles of the DC side are connected in parallel with the positive and negative poles of the power storage branch and are connected to the positive and negative poles of the DC bus through an electric operation switch.

Preferably, the BMS protection management module includes a diode D, a charging contactor M, and a battery management system BMS;

the diode D is connected in series in a branch of the storage battery pack, the positive electrode of the diode D is connected with the positive electrode of the storage battery pack, and the negative electrode of the diode D is connected with the positive electrode of the direct current side of the AC/DC rectifying module; and in the normal running state, the diode is in a cut-off state;

the charging contactor M is a triode, the source electrode of the charging contactor M is connected with the positive electrode of the storage battery pack, the drain electrode of the charging contactor M is connected with the positive electrode of the direct current side of the AC/DC rectifying module, and the grid electrode of the charging contactor M is connected with the battery management system BMS;

the battery management system BMS is also connected with the electric operation switch and the storage battery pack, is communicated with the intelligent control platform and is used for controlling the opening and closing of the charging contactor M and the electric operation switch.

The intelligent control platform comprises a data acquisition unit, a state monitoring unit, a comprehensive processing unit, a fault alarm unit, an intelligent control unit and a data storage and transmission unit;

the data acquisition unit is used for communicating with the BMS protection management module of each power supply module, collecting voltage, current and temperature data of the storage battery pack of each power supply module, and outputting voltage and current data by alternating current input and direct current output of the charging module; simultaneously, the total output direct-current voltage and current of the direct-current power supply system are directly collected in real time, and the total input alternating-current voltage and current of the direct-current power supply system are directly collected;

The state monitoring unit is communicated with the BMS protection management module of each power supply module and is used for monitoring the opening and closing and conducting states of the alternating current inlet switch, the electric operation switch and the diode D and the charging contactor M in the BMS protection management module of each power supply module; meanwhile, the switching state of the total input switch and the total output switch of the alternating current power supply is directly monitored;

the comprehensive processing unit is used for performing fault analysis and judgment on the real-time data and the state information acquired by the data acquisition unit and the state monitoring unit;

the fault alarm unit is used for sending an alarm signal when the comprehensive processing unit judges that a fault exists, and uploading the alarm information to the substation side monitoring background and the remote monitoring platform through the data storage and transmission unit;

the intelligent control unit is used for communicating with the power supply module according to the research and judgment result of the comprehensive processing unit, issuing instructions, intelligently adjusting the output voltage of the power supply module and automatically switching on and switching off the electric operation switch of the power supply module;

and the data storage and transmission unit is used for recording fault messages and historical records and interfacing with a substation end monitoring background and a remote monitoring platform.

The invention has the beneficial effects that compared with the prior art:

1. The invention provides a charging and storing integrated power supply module, each power supply module is a miniature direct current power supply and comprises a charging module, a 220V storage battery pack, a management protection function module and the like, and further adopts an N+1 configuration scheme to form a novel modularized direct current power supply system by N+1 charging and storing integrated power supply modules. The system adopts an energy splitting mode, a traditional direct-current power supply single-group high-capacity battery pack and a single charging device are split into a plurality of sets of power supply modules of a small-capacity battery pack and a small-power rectifying unit, and the power supply modules are formed by bridging the power supply modules in parallel, so that the power supply modes of one charging and one accumulating of the traditional direct-current power supply and DC/DC boosting of the parallel direct-current power supply are completely broken, and the operation safety and reliability are remarkably improved.

The novel modularized direct-current power supply system is applied to 220V direct-current power supply systems for power plants and substations, and can be popularized to 110V direct-current power supply systems. Lithium batteries are recommended for battery packs, and lead-acid batteries or other types of battery packs may also be used. Under the normal operation condition, each charging and storing integrated power supply module rectifies alternating current into direct current and supplies power to a direct current load; when alternating current is in power failure, the storage battery inside each charging and storing integrated power module is used for carrying out backup power supply; each charging and storing integrated power module adopts an 'N+1' configuration, wherein 1 charging and storing integrated power module can be in a hot standby state.

2. The invention provides an intelligent management and control platform of a power supply module, which monitors the running state of each charging and storing integrated power supply module and realizes the on-line monitoring, intelligent management and control and alarm disposal of the power supply module. The intelligent operation and maintenance control system can be communicated with a transformer substation monitoring background, and can be used for realizing module fault handling, automatic isolation of an overheat power supply module, module battery charging, module hot standby, charging module carrying capacity testing and storage battery carrying capacity testing;

and the working power supply of the intelligent control platform is taken from a direct current bus, when an alternating current power failure occurs, the system takes electricity from the storage battery pack through the direct current bus, and the monitoring of the state of each power supply module in the screen and the receiving and storing functions of abnormal alarm information can not be lost.

3. The invention provides an intelligent operation and maintenance control method, which realizes intelligent automatic hot standby alternation of a single power supply module based on each unit of an intelligent management and control platform, realizes automatic isolation of an overheat power supply module, and realizes output capability verification of an AC/DC rectifying module and load capability test of a storage battery pack. If the alternating current input and output voltage, the output current, the battery temperature and other data of the power supply module are collected and monitored in real time, the alternating current input of the power supply module and the real-time load condition of the power supply module can be mastered in real time, faults can be found in time, and an alarm can be given out in time; through intelligent control of the power supply module, the fault power supply module can be rapidly identified and isolated, and further accidents are prevented; realize the quick isolation of overheated power module, effectively alleviate the overheated situation of group battery.

Drawings

FIG. 1 is a block diagram of a DC power module according to the present invention;

FIG. 2 is a block diagram of a novel DC power supply system of the present invention;

FIG. 3 is a functional block diagram of an intelligent control platform of the power module of the present invention;

fig. 4 is a schematic block diagram of an operation and maintenance control method of the dc power supply system according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. The embodiments described herein are merely some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art without making any inventive effort, are within the scope of the present invention.

As shown in fig. 1, embodiment 1 of the present invention provides a charging and storing integrated dc power module, and proposes a design scheme of a charging and storing integrated power module of "battery+bms+charging module": the AC/DC rectifying module and a group of 220V storage batteries are integrated in parallel, and the functions of management, protection, monitoring and the like are integrated into a power module, and each power module has the functions of charging and standby power and is equivalent to a miniature direct current power supply system.

In a preferred but non-limiting embodiment of the present invention, the dc power module includes a charging module, a battery branch, a BMS protection management module, and an electrically operated switch;

the charging module comprises an alternating current side and a direct current side, wherein the alternating current side is connected with alternating current input through a wire inlet breaker, and the direct current side is connected with a storage battery branch in parallel and is connected into a direct current bus through an electric operation switch;

and the BMS protection management module is used for controlling the charging module, the storage battery branch and the electric operation switch, so as to realize charging and storage integrated protection and management.

Further preferably, the charging module is an AC/DC rectifying module, the AC side of the charging module is connected with an AC input through a circuit breaker S, and the positive and negative poles of the DC side are connected in parallel with the positive and negative poles of the power storage branch and are connected to the positive and negative poles of the DC bus through an electric operation switch.

The BMS protection management module comprises a diode D, a charging contactor M and a battery management system BMS;

the diode D is connected in series in a branch of the storage battery pack, the positive electrode of the diode D is connected with the positive electrode of the storage battery pack, and the negative electrode of the diode D is connected with the positive electrode of the direct current side of the AC/DC rectifying module;

in a normal running state, the voltage of the storage battery pack of the 220V direct current power supply system is kept at 220V, and the output voltage of the charging module is generally 220V of high-voltage rated voltage, for example, 234V is set, and the diode is in a cut-off state;

In fig. 1, an AC input is connected to an external AC 380V power source, and the AC/DC rectification module is supplied with power through a circuit breaker S. Under the normal power supply condition, the electric operation switch is in a closed state, the alternating current input is rectified into direct current through the AC/DC rectification module, and the direct current bus is supplied with power through the electric operation switch. If the power supply module fails or overhauls, the power supply module can be withdrawn from operation by controlling the electric operation switch to be disconnected.

The 220V battery is connected in series with diode D and coupled to the charge output circuit. When the AC/DC rectifying module works normally, the output direct current is higher than the voltage of the storage battery, at the moment, the diode D is in a reverse cut-off state, the storage battery is not output, and the storage battery cannot be charged through the AC/DC rectifying module. When the alternating current input loses power, the direct current side voltage of the AC/DC rectifying module is not output, the diode D is conducted in the forward direction, and the storage battery pack continues to supply power for the direct current bus, so that the direct current bus is ensured not to lose power.

The battery pack is configured with a battery management system BMS in parallel, and can monitor the voltage and temperature conditions of the single battery and the whole battery of the battery pack. When the voltage of the storage battery pack is lower than a set threshold value, such as 198V, the battery management system BMS controls the charging contactor M to be closed, the diode D is short-circuited, and the AC/DC rectifying module charges the storage battery pack. After the charging reaches the set cut-off voltage of the battery pack, for example, 220V, the battery management system BMS controls the charging contactor M to be opened, and stops charging the battery pack.

The BMS protection management module can control the charging of the storage battery pack, and comprises the following steps: when the voltage value of the storage battery pack is monitored in real time by the BMS protection management module, the preset value of the 220V direct current power supply system can be set to 90% of rated direct current bus voltage (198V) when the voltage value is up to or lower than the preset value, the BMS protection management module sends an application requesting charging to the intelligent management and control platform, the intelligent management and control platform carries out the research and control on whether charging can be carried out, when the research and control result is that charging can be carried out, an allowable charging instruction is issued to the BMS protection management module, otherwise, a temporary charging instruction is issued, and the issuing of the chargeable instruction is delayed until the research and control result is that charging can be carried out. After the BMS protection management module receives the chargeable command, the BMS protection management module sends a brake opening command to control the electric operation switch to be opened, sends a closing command to control the charging contactor M to be closed, charges the storage battery, and when the voltage value of the storage battery reaches a set cut-off voltage, for example 220V, the BMS protection management module sends an opening command to control the charging contactor M to be opened, stops charging the storage battery, and sends a closing command to control the electric operation switch to be closed, so that the storage battery is restored to a normal power supply state of the direct-current load. In the process that the BMS protection management module controls the charging of the storage battery, when the cut-off voltage is not reached in the process of charging the storage battery, but a command of stopping charging and recovering normal power supply of the intelligent management and control platform is received, the command of the intelligent management and control platform is preferentially executed, and the charging is immediately stopped and the normal power supply state is recovered.

The BMS protection management module not only operates when the storage battery is charged, but also comprises: firstly, overheat protection is disconnected, a BMS protection management module monitors the temperature of a pole of a storage battery, when the temperature of a storage battery pack is higher than a set fault alarm temperature, such as 60 ℃, and the storage battery pack is researched and judged by an intelligent management and control platform, the storage battery pack can be taken out of operation, and when an instruction for allowing isolation is sent out, the BMS protection management module sends a brake-separating instruction to control an electric operation switch to be disconnected, and the storage battery pack is taken out of operation and is automatically isolated; when the temperature of the storage battery pole is monitored to restore to the normal working temperature, if the temperature is lower than 45 ℃, the BMS protection management module directly sends a closing instruction to control the electric operation switch to be closed, and the module restores to normal operation. Secondly, the fault is disconnected, when the BMS protection management module monitors the fault of the module, the BMS protection management module sends out a brake separating instruction to control the electric operation switch to be disconnected, and the module directly exits from running. After the fault is opened, the rear part can be closed after the fault is detected manually, and the automatic closing can not be realized.

In summary, when the BMS protection management module fails or overheats, the BMS protection management module can control the electric operation switch to be turned off, so that the dc power module is out of operation; wherein, the overheat treatment is allowed by an intelligent control platform, and the detailed description is shown in the following operation and maintenance control method; when the alternating current input is normal, the electric operation switch is controlled to be closed, the charging module is controlled to supply power to the direct current bus through the electric operation switch, and meanwhile, the storage battery pack is controlled to be free of output and is not charged by the charging module; when the alternating current input loses power, the electric operation switch is controlled to be closed, and the storage battery pack is controlled to supply power for the direct current bus through the electric operation switch, so that the direct current bus is ensured not to lose power; when the alternating current input is normal and the voltage of the storage battery is lower than a set threshold value, the electric control switch is controlled to be turned off, the charging module is controlled to charge the storage battery, and after the charging reaches the set cut-off voltage of the storage battery, the charging module is controlled to stop charging the storage battery. Wherein the charging is allowed by the intelligent control platform, and the detailed description is as follows.

As shown in fig. 2, embodiment 2 of the present invention provides a modular dc power system, which adopts an "energy splitting" manner to split a single set of high-capacity battery and a single set of charging device of a conventional dc power into multiple sets of low-capacity battery and power supply modules of a low-power rectifying unit, and to supply power to the multiple power supply modules in parallel, thereby forming a novel dc power system. As shown in fig. 2, the dc power supply system includes n+1 power supply modules as described in embodiment 1;

n+1 power supply modules are connected in parallel for supplying power, wherein the N power supply modules are used for completely matching the maximum design capacity of a charger and a storage battery pack of a traditional direct current power supply system, and the remaining 1 power supply module is used as redundancy; in the embodiment, at most one power module can be used as hot standby in the system at the same time;

the configuration scheme of the number of the power supply modules in the direct-current power supply system is an 'n+1' configuration scheme, namely N power supply modules are used for completely matching the maximum design capacity of a traditional charger and a storage battery pack, and 1 more power supply modules are used as capacity redundancy. The maximum design capacity of the traditional charger and the storage battery and the standard capacity of a single module jointly determine the configuration quantity of the power supply modules. The larger the maximum design capacity of the traditional charger and the storage battery pack is, the smaller the single capacity of a single power supply module is, the more modules are required to be configured for the direct current system, the more flexible the intelligent control operation and maintenance operation is, the higher the overall safety of the system is, and meanwhile, the more the manufacturing cost of the system is. And the operation and maintenance flexibility, the safety and the economy are comprehensively considered, and the capacity of a single module should be reasonably configured. It is recommended that the rated capacity of the storage battery of the single module is not lower than 50Ah, and the rated current of the charging module is not lower than 30A.

For example, a traditional direct current power supply system of a 110kV transformer substation is provided with 1 group of 300Ah storage battery packs and 1 set of charging device with rated current of 200A, the rated capacity of a storage battery of a single module is 50Ah, and the rated current of a charging module is 30A.

In specific implementation, the direct current power supply system can be applied to 220V direct current power supply systems for power plants and substations, and can also be popularized to 110V direct current power supply systems. Lithium batteries are recommended for battery packs, and lead-acid batteries or other types of battery packs may also be used. Under the normal operation condition, each power supply module rectifies alternating current into direct current and supplies power for a direct current load; when alternating current is in power failure, a storage battery pack in each power supply module is used for carrying out backup power supply; each power module is configured by 'N+1', wherein 1 power module can be in a hot standby state.

In specific operation, the operation states of the modules are controlled by the intelligent control platform provided in the following embodiment 3 and the operation and maintenance control method provided in the embodiment 4.

The embodiment 3 of the invention provides an intelligent control platform which is used for on-line monitoring, intelligent control and fault alarming of the operation of the power supply module of the direct current power supply system in the embodiment 2;

as shown in fig. 3, the intelligent control platform comprises a data acquisition unit, a state monitoring unit, a comprehensive processing unit, a fault alarm unit, an intelligent control unit and a data storage and transmission unit;

the data acquisition unit is mainly used for communicating with the BMS protection management module of each power supply module, collecting voltage, current and temperature data of the storage battery pack of each power supply module, and outputting voltage and current data by alternating current input and direct current output of the charging module; simultaneously, the total output direct-current voltage and current of the direct-current power supply system are directly collected in real time, and the total input alternating-current voltage and current of the direct-current power supply system are directly collected;

the state monitoring unit is communicated with the BMS protection management module of each power supply module and is used for monitoring the opening and closing and conducting states of the alternating current inlet switch, the electric operation switch and the diode D and the charging contactor M in the BMS protection management module of each power supply module; meanwhile, the switching state of the total input switch and the total output switch of the alternating current power supply is directly monitored; so as to grasp the alternating current input condition, the switching state of each power module and the charging state of the storage battery.

The comprehensive processing unit is mainly used for performing fault analysis and judgment on the real-time data and the state information acquired by the data acquisition unit and the state monitoring unit; on one hand, the intelligent control unit can send out power supply module output voltage adjustment and power supply module output electric operation switch switching instruction according to the research and judgment result, and on the other hand, the fault alarm unit can be controlled to send alarm signals and information according to the research and judgment result; the faults comprise AC power failure, charging module faults, unbalanced output among power supply modules, abnormal switch state and the like.

The fault alarm unit is mainly used for sending out an acousto-optic alarm signal when the comprehensive processing unit judges that the faults such as alternating current power failure, a charging module fault, unbalanced output among power supply modules, abnormal switch state and the like exist, and uploading alarm information to a substation station end monitoring background and a remote monitoring platform through the data storage and transmission unit;

the intelligent control unit is mainly used for communicating with the power supply module according to the research and judgment result of the comprehensive processing unit, intelligently adjusting the output voltage of the power supply module and automatically switching on and off the electric operation switch of the power supply module;

when the dc power supply system of embodiment 2 is subjected to operation and maintenance control, the integrated processing unit of the intelligent control platform mainly performs fault determination, the intelligent control unit performs fault handling, and the fault alarm unit performs fault alarm, which is specifically described in the operation and maintenance control method of embodiment 4.

The intelligent control unit is communicated with the BMS protection management module of each power supply module, issues a command of whether to allow charging and isolation, is communicated with the charging module of each power supply module, and adjusts the output state of each power supply module by controlling and changing the output direct-current voltage set value of each charging module, so that the module hot standby strategy control, the charging module load capacity test and the storage battery load capacity test are realized.

The data storage and transmission unit is mainly used for recording information such as fault messages, historical records and the like, is connected with a substation station monitoring background in a butt joint mode through a 485 communication interface, and is connected with a remote monitoring platform through an Ethernet communication interface by adopting a DL/T860 protocol.

Further preferably, the working power supply of the intelligent control platform is taken from a direct current bus, and when alternating current input power failure occurs, the direct current bus is used for taking power from the storage battery, so that the monitoring of the states of all power supply modules in the screen and the receiving and storing functions of abnormal alarm information are not lost.

The BMS protection management module and the intelligent management and control platform are related as follows: the BMS protection management module is equivalent to a monitoring system (sub-monitoring) of each direct-current power supply module, and the intelligent management and control platform is equivalent to a general monitoring system of the whole direct-current power supply system.

BMS protects management module and is responsible for monitoring the running state who corresponds single module body, includes: voltage current temperature data of the storage battery pack; AC input and DC output voltage and current data of the charging module; the switching state and the conduction state of the alternating current inlet switch, the electric operating switch, the diode and the charging contactor are respectively realized; when the module fails, overheats and the battery is charged, the electric operation switch is controlled to be disconnected, and the module is withdrawn from operation; the charging contactor can be controlled to be opened and closed to charge the storage battery pack, and the overheat isolation and the battery charging need to receive main monitoring permission instructions; the system can communicate with an intelligent management and control platform (a general monitoring system), upload all collected data and running states to the general monitoring, and receive control instructions issued by the general monitoring.

The intelligent control platform is used for total monitoring, receiving information of sub-monitoring of all modules, simultaneously monitoring total alternating current input and total direct current output voltage and current data of a direct current power supply system and on-off state of a switch, comprehensively judging the information, and making an instruction about whether to allow the modules requesting overheat isolation and battery charging according to total real-time on-load conditions of the direct current power supply system and output conditions and running states of all the modules, and performing module hot standby strategy control, charging module on-load capability test and storage battery on-load capability test. The hot standby and on-load test intelligent management and control platform is realized by communicating with each charging module and controlling the output direct-current voltage value.

Embodiment 3 of the present invention provides an operation and maintenance control method for a dc power supply system according to embodiment 2, which specifically includes the following steps:

the operation and maintenance control of the direct-current power supply system is realized by monitoring and controlling the running states of the charging module, the storage battery pack and the electric operation switch of each module through the BMS protection management module of each module and the intelligent management and control platform in the embodiment 3;

the operation and maintenance control covers module fault handling, automatic isolation of an overheat power supply module, module battery charging, module hot standby, charging module carrying capacity testing and storage battery carrying capacity testing.

Further preferably, in order to ensure that the safe and reliable continuous normal power supply of the direct-current power supply system is a priority target, the execution priority of the above functions is ordered as follows:

the module fault handling is superior to the automatic isolation of the overheat power supply module, the automatic isolation of the overheat power supply module is superior to the charging of the module battery, the charging of the module battery is superior to the hot standby of the module, the priority of the hot standby of the module is the same as that of the charging module carrying capacity test and the storage battery carrying capacity test, but the hot standby of the module cannot be performed simultaneously with the charging module carrying capacity test and the storage battery carrying capacity test. The operation and maintenance control method is shown in the execution flow chart 4, and is specifically described as follows:

(1) Normal operation

The direct current power supply system consists of N+1 power supply modules which are connected in parallel, and under normal conditions, the N+1 power supply modules supply power to the direct current system simultaneously, and the running states of the modules are monitored and controlled through the BMS protection management module and the intelligent management and control platform of the modules.

The intelligent management and control platform comprehensive processing unit processes the data of the data acquisition unit in real time and calculates the following data:

1) Calculating the system load ratio F in real time, namely the total real-time output current I of the direct-current power supply system _{Total (S)} And the ratio of the rated output current sum of the charging modules of the power supply module which normally operates. The system load ratio F is less than 1, and the actual load ratio is less than or equal to 0.9 in order to prevent overload locking protection of the charging module.

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Wherein I is _{Total (S)} For the total real-time output current of the direct-current power supply system, I _N Rated output current of charging module for single power supply module, X _{Failure of} The number of power supply modules for failure and shutdown is X _Superheating The number of power supply modules for overheat shutdown is X _{Charging method} X is the number of power modules in a state of charge for the battery pack _{Hot standby} The number of power modules in the hot standby state.

2) And calculating the current sharing unbalance degree D among the power supply modules in real time, namely, the ratio of the difference value of the current value of the module with the largest output direct current to the average output current value of the module in the normal running state. D should be less than.+ -. 5%. When the requirements are not met, the adjustment treatment is performed in real time, and the unbalanced fault treatment description is output among the power supply modules.

Wherein I is _i The current value is output by the power module i.

(2) Module fault handling

The comprehensive processing unit of the intelligent control platform carries out fault judgment, the intelligent control unit carries out fault treatment, and the fault alarm unit carries out fault alarm.

The faults comprise alternating current power failure, charging module faults, unbalanced output among power supply modules and abnormal switch state faults.

1) Ac power loss

When the alternating current input voltage and current of each power supply module are monitored to be 0, the total alternating current input voltage U of the power supply system _A 、U _B 、U _C And current I _A 、I _B 、I _C Also 0, at the same time, each power module exchanges the incoming line switch S ₁ …S _N+1 When the total alternating current inlet switch J is in a normal closed state, judging that an alternating current power failure occurs;

after the alternating current power failure is judged, the storage battery packs of the modules directly supply power for the direct current buses together, and the BMS protection management module and the intelligent management and control platform do not need to wait for instructions.

2) Failure of charging module

When each power supply module alternating current inlet wire switch S is monitored ₁ …S _N+1 When the total alternating current inlet wire switch J is in a normal closed state, the total alternating current input voltage U of the power supply system _A 、U _B 、U _C And current I _A 、I _B 、I _C The state is normal;

a power supply module such as T1 power supply module has normal AC input voltage and is not in the control state of overheat, battery charging, hot standby, charging device load test, storage battery load test, etc., but has no current output on the DC side, i.e. I ₁ If the power supply is 0 and the input and output of other modules are normal, judging that the charging module of the T1 power supply module fails;

after judging that the charging module fails, the intelligent control unit communicates with the BMS protection management module of the module, and the BMS protection management module controls the electric operation switch of the module to be disconnected to isolate the failure.

If the power supply module fails and exits, the intelligent management and control platform comprehensive processing unit calculates the system load ratio F at the moment:

2) If F is more than 0.9, the intelligent control unit firstly restores the module (if any) in the hot standby state to the normal running state, and calculates F again, if F is less than or equal to 0.9, the operation is stopped;

3) If F is still more than 0.9, the intelligent control unit restores the charged module (if any) to a normal running state, and calculates F again, if F is less than or equal to 0.9, the operation is stopped;

4) If F is still more than 0.9, the intelligent control unit restores the overheat isolated module (if any) to a normal running state, and calculates F again, if F is less than or equal to 0.9, the operation is stopped;

5) If F is still more than 0.9, the method is an extreme case, which indicates that the number of modules which are out of order is large, manual fault handling should be immediately organized, and the fault modules are restored to be normal as soon as possible.

When the module in the step 2) or the step 3) does not exist, automatically skipping the corresponding step and executing the next step; when the modules in the 4) are not existed, the artificial fault treatment is organized, according to the configuration scheme of 'N+1', N modules can be matched with the maximum load possibly occurring in the transformer substation, and when the 'N+1' modules are in the normal operation state, the load ratio F generally does not exceed 0.9. If F exceeds 0.9, the fault module exists with high probability, and after the fault module returns to normal, the F high probability is less than or equal to 0.9. If the 'n+1' modules are in normal operation state, F is still larger than 0.9, which indicates that the total capacity of the existing modules cannot well match the load demand of the transformer substation, the capacity of the direct current system is expanded by considering the increased modules.

3) Output imbalance between power supply modules

When the power supply module is not in the control states of overheat, battery charging, hot standby, charging module load test, storage battery load test and the like, and the current sharing unbalance degree among the direct current outputs of all the power supply modules in the normal operation state is more than +/-5%, the output unbalance among the power supply modules is judged, and the fault alarm unit sends out an output unbalance alarm among the power supply modules.

The intelligent management and control platform comprehensive processing unit is used for carrying out unbalance judgment, and the calculation mode of the current sharing unbalance degree is as follows:

Current value I output by single module _i And average value I of output currents of all running modules _{Average of} Maximum difference between (max|I _i -I _{Average of} I), the maximum difference value is compared with the module output average value I _{Average of} And dividing the mixture to obtain the product.

When the unbalanced output alarm occurs between the power supply modules, the intelligent control unit communicates with the charging module of the power supply module with the largest direct current output, and the direct current output voltage of the intelligent control unit is finely adjusted downwards, for example, the original output voltage is 234V, the direct current output current of the module can be reduced after the output voltage of the module charging module is reduced, the intelligent control platform comprehensive processing unit calculates the current unbalanced flow in real time, and when the balanced flow is lower than +/-5%, the fine adjustment of the voltage is stopped, and the alarm is released.

4) Abnormal fault of switch state

Real-time monitoring of alternating current incoming line switch S of each module ₁ …S _N+1 And when the switch is in an open state, an abnormal alarm is given out when the switch is monitored, except that the fault maintenance is manually disconnected when the operation states of the total alternating current inlet switch J and the total direct current output switch are in a normal closed state. Such as an ac line switch S ₁ When the T1 module is in a disconnection state, the T1 module has no alternating current input and cannot normally output, and the T1 module needs immediate manual overhaul treatment.

When the opening and closing states of the electric operation switches of the power supply modules are not consistent with the instruction states, an abnormal alarm of the electric operation switch states is sent out. For example, when the BMS controls the electric operation switch to be turned off according to a charging instruction, the electric operation switch cannot be turned off normally, and immediate manual maintenance is required.

(3) Automatic isolation of overheat power supply module

Setting the temperature fault alarm temperature T of storage battery inside power supply module _{Alarm device} The BMS protection management module monitors the real-time temperature of each battery positive and negative pole column of the storage battery of the power supply module, and feeds back the temperature value to the intelligent management and control platform, and when the maximum temperature is higher than the preset fault alarm temperature, namely T _{Real time} ≥T _{Alarm device} The BMS protection management module sends an overheat isolation application to the intelligent management and control platform;

the intelligent management and control platform comprehensive processing unit calculates the system load ratio F after the module overheat isolation exits:

1) If F is less than or equal to 0.9, the module can be withdrawn from operation, the intelligent control unit sends an instruction for allowing isolation to the BMS protection management module, and the BMS protection management module sends a brake-separating instruction to control the electric operation switch to be disconnected, so that the module is withdrawn from operation. When the temperature of the pole column of the storage battery of the module is monitored to be in a normal working temperature range, if the temperature is set to be lower than 45 ℃, the BMS protection management module sends a closing instruction to control the electric operation switch to be closed, and the intelligent control platform is not required to instruct the module to resume normal operation;

2) If F is more than 0.9, the intelligent control unit firstly restores the module (if any) in the hot standby state to the normal running state, and calculates F again, if F is less than or equal to 0.9, the intelligent control unit performs the operation of 1);

3) If F is still more than 0.9, the intelligent control unit restores the charged module (if any) to a normal running state, and calculates F again, if F is less than or equal to 0.9, the operation of 1) is carried out;

4) If F is still more than 0.9, the intelligent control unit sends out a suspending and isolating instruction to the BMS protection management module, the module continues to operate, and after the fault module (if any) is recovered to be normal, F is calculated in real time to be less than or equal to 0.9, and then the operation of 1) is carried out.

When the module in the step 2) or the step 3) does not exist, automatically skipping the corresponding step and executing the next step; and (3) when the modules in the step 4) are not present, the number of the added modules is considered to expand the capacity of the direct current power supply system.

(4) Module battery charging

The BMS protection management module monitors the voltage value of each power module storage battery in real time, when the voltage value reaches or is lower than a preset value, the preset value of the 220V direct current power system can be set to be 90% of rated direct current bus voltage, namely 198V, and the BMS protection management module sends an application for requesting charging to the intelligent management and control platform;

the intelligent management and control platform comprehensive processing unit calculates a system load ratio F after the module is charged and exits:

1) If F is less than or equal to 0.9, the intelligent control unit sends out an instruction for allowing charging to the BMS protection management module, and after the BMS protection management module receives the chargeable instruction, the BMS protection management module sends out a brake separating instruction, controls the electric operating switch to be opened, and sends out a closing instruction to control the charging contactor M to be closed, so that the storage battery pack is charged. When the voltage value of the storage battery reaches the set cut-off voltage, for example 220V, the BMS protection management module sends out an opening instruction to control the charging contactor M to be opened, the storage battery is stopped to be charged, and a closing instruction is sent out to control the electric operation switch to be closed, so that the storage battery is restored to a normal power supply state of the direct current load. When the cut-off voltage is not reached in the charging process of the storage battery, if an instruction of stopping charging and recovering normal power supply of the intelligent control platform is received, the instruction of the intelligent control platform is preferentially executed, and the charging is immediately stopped and the normal power supply state is recovered.

2) If F is more than 0.9, the intelligent control unit restores the module (if any) in the hot standby state to the normal running state, and calculates F again, if F is less than or equal to 0.9, the operation of 1) is carried out;

3) If F is still more than 0.9, the intelligent control unit sends out a charge suspending instruction to the BMS, the module continues to operate, and after the fault module (if any) is recovered to be normal and the overheat isolation module is recovered to be normal, F is less than or equal to 0.9 in real time, and then the operation of 1) is carried out.

Automatically skipping 2) when the module in the 2) does not exist, and executing 3); and 3) when the modules in the step 3) do not exist, the number of the added modules is considered to expand the capacity of the direct current power supply system. Namely, according to the configuration scheme of 'N+1', N modules can be matched with the maximum load possibly occurring in a transformer substation, when 'N+1' modules are in normal operation, the load ratio F is generally not more than 0.9, if F exceeds 0.9, a fault module or an overheat isolation module exists in a large probability, and after the fault module and the overheat module are recovered to be normal, the F large probability is less than or equal to 0.9. If the 'n+1' modules are in normal operation state, F is still larger than 0.9, which indicates that the total capacity of the existing modules cannot well match the load demand of the transformer substation, the capacity of the direct current system is expanded by considering the increased modules.

(5) Modular hot standby

When the novel direct current power supply system formed by connecting the 'N+1' power supply modules in parallel is adopted, the direct current output voltages of all the power supply modules are the same under normal conditions, and the direct current bus voltage is supported together to supply power for a direct current load. The invention can convert 1 power supply module meeting the condition into a hot standby state after intelligent judgment, and reduces the output voltage U of the AC/DC rectifying module DC side of the power supply module to be lower than the DC output voltage U of other power supply modules _{Bus bar} But higher than its battery voltage U _{Battery cell} U, i.e. U _{Battery cell} ＜U＜U _{Bus bar} The output is reduced and suspended, and the direct current load is borne by the rest N power supply modules. Specific:

the priority of the corresponding operation of the fault, overheat and charging module is higher than that of the hot standby operation, wherein the fault module is withdrawn and belongs to the forced uncontrollable operation, the overheat isolation, the charging withdrawal and the hot standby withdrawal are all in the non-forced controllable operation, the duty of the module is to meet the normal power supply of the direct current load, the reflected index is the load ratio F, and when F is less than or equal to 0.9, the module is proved to be capable of well fulfilling the normal power supply duty of the direct current load. The failure module is withdrawn and belongs to uncontrollable factors, when the failure module appears, the power supply capacity of the module is inevitably reduced, and the load ratio F value is increased, at the moment, the rest non-failure modules are controlled to preferentially ensure power supply, namely the requirement that F is less than or equal to 0.9 is met, and the failure modules are organized and repaired manually as soon as possible; if the system has no fault module or has a fault module but does not influence the load ratio F to be less than or equal to 0.9, the controllable operations such as overheat isolation (if needed), charging (if needed), hot standby and the like of the modules can be sequentially carried out according to the priority, and the load ratio F to be less than or equal to 0.9 when the controllable operations are ensured to be completed. When the controllable operations such as overheat isolation (if needed), charging (if needed), hot standby and the like of the modules are sequentially carried out according to the priority, once the load ratio F is more than 0.9, the controllable operations are immediately ended, and the normal power supply of the modules is preferentially ensured. The hot standby operation is last performed among all controllable operations. The hot standby strategy can be executed on the module meeting the following conditions on the premise that the normal power supply of the direct-current power supply system can still be met after the failure, overheat and the withdrawal of the charging module are ensured:

A: the maximum value of the temperatures of the positive and negative poles of each battery of the storage battery of one power supply module in normal operation is higher than the temperatures of the positive and negative poles of each battery of the storage battery of the other power supply modules in normal operation, and the maximum value temperature is lower than the preset fault alarm temperature; the comprehensive processing unit judges the data;

T _{other modules of normal operation} ＜T _{Hot standby module} ＜T _{Alarm device}

B: the intelligent management and control platform comprehensive processing unit calculates a system load ratio F after the module hot standby exits:

for example, the temperature of the positive electrode column of a certain battery in the No. 1 module battery pack is 50 ℃, and the positive electrode column is the highest value in all normal operation modules. And the load ratio F is less than or equal to 0.9 after the No. 1 module is withdrawn, so that the No. 1 module can be switched into a hot standby state.

If F is less than or equal to 0.9, the intelligent control unit heats the module to reserve under the charging moduleThe command controls and reduces the output voltage U of the AC/DC rectifying module of the power supply module to be lower than the DC output voltage of other power supply modules which normally operate but higher than the voltage U of the storage battery pack _{Battery cell} U, i.e. U _{Battery cell} ＜U＜U _Others Suspending the output and switching to a hot standby state;

if F is more than 0.9, suspending executing hot standby, and continuing normal operation of the module;

When the two conditions A, B cannot be met at the same time, the hot standby state cannot be switched to, the hot standby state should be stopped immediately and the normal operation state is restored, and other modules meeting the condition A, B are switched to the hot standby state, and the cycle is repeated.

During the hot standby, once the uncontrollable event of module failure occurs, or the controllable event of higher priority such as overheat isolation, charging and the like of the module is needed, the hot standby is immediately terminated when necessary in order to meet the requirement that F is less than or equal to 0.9.

(6) Charging module load capacity test

The load capacity test of each power supply module charging module (namely the AC/DC rectifying module) can be carried out regularly, and the recommended test period is 1 month and 1 time for each power supply module, and the test duration is 5 minutes for each time; testing the modules in turn;

the power supply module for carrying out the load capacity test of the charging module needs to be a power supply module in a normal state, and when the module is in a fault, overheat and charging state, the load test cannot be carried out;

the intelligent control unit issues a load capacity test instruction to the module to be tested charging module, and controls the output voltage U of the AC/DC rectifying module DC side of the power module to be raised so as to be higher than the output voltage U of other normal operation power modules _Others U > U _Others Preferentially ensuring the maximum output of the module; each BMS protection management module monitors the output current and voltage of the charging module and transmits data to the intelligent management and control platform;

if the rated direct current output current of the module charging module is larger than the total load current of the system, the module is fully loaded, and other modules cannot output force; if the rated direct current output current of the module charging module is smaller than the total load current of the system, the module charging module outputs the rated direct current to the rated direct current, and the residual load current is equally born by other modules;

after the test duration is over, the intelligent control unit issues a test instruction for stopping carrying capacity to the charging module of the test module, and controls and reduces the output voltage U of the AC/DC rectifying module of the power module, which is the same as the DC output voltage of other normal operation power modules;

the comprehensive processing unit judges the carrying capacity of the module charging module, when the direct current output of the module charging module reaches the maximum system total load current or the rated maximum current thereof, the carrying capacity is judged to be qualified, otherwise, the carrying capacity is disqualified, and manual treatment should be performed in time.

For example, when each module normally operates, the voltage of the direct current output side is 234V, the direct current output voltage of the module to be tested is adjusted to 240V, the rated direct current output current of the module to be tested is assumed to be 30A, the real-time total load current of the system is 25A, at this time, the module should output 25A, other modules do not exert force, if the output is less than 25A, the load capacity is not qualified; if the real-time total load current of the system is 65A, the module should output 30A, and the rest 35A load current should be equally divided by other normal operation modules, if the output is less than 30A, the load capacity is not qualified.

(7) Storage battery pack load capacity test

The load capacity test of the storage battery pack of each power supply module can be carried out regularly, and the recommended test period is 1 month and 1 time for each power supply module, and the test duration is 5 minutes for each time; all power supply modules in normal state are tested simultaneously;

the power supply module for carrying out the load capacity test of the storage battery pack needs to be a power supply module in a normal state, and when the module is in a fault, overheat and charging state, the load test of the storage battery pack cannot be carried out;

the intelligent control unit issues instructions to the charging modules of the modules to be tested, and controls and reduces the output voltage U of the AC/DC rectifying module direct current side of each power supply module to be lower than the voltage of the storage battery pack, butNot less than 90% of rated DC bus voltage, such as 220V DC system, 90% of rated DC bus voltage is 198V, i.e. 90% U _{Bus bar} ≤U＜U _{Battery cell} The method comprises the steps of carrying out a first treatment on the surface of the At the moment, the charging modules of the test modules stop outputting, the storage battery of each test module carries a system direct current load, and the BMS protection management modules monitor the output current and voltage of the storage battery and transmit the data to the intelligent management and control platform;

after the test duration is over, the intelligent control unit issues instructions to the charging modules of the test modules to control the output voltage U of the AC/DC rectifying module of each test power module to be increased to a normal running state value; each test module resumes normal power supply by the charging module;

The comprehensive processing unit judges the carrying capacity of the test module storage battery pack, and when the direct current of the test module storage battery pack is not output or the voltage of the test module storage battery pack is reduced too fast, the specified test time is not completed, the carrying capacity of the storage battery pack is judged to be unqualified, and the storage battery pack is manually disposed in time.

For example, a 220V direct current system, 5 modules simultaneously carry out the load capacity test of the storage battery, after the test is started, 4 groups of modules simultaneously output current, 1 group of modules do not have current output, the load capacity of the groups is disqualified, open-circuit faults possibly exist in the storage battery, and the storage battery should be manually disposed in time. For example, after the remaining 4 groups of batteries are tested for 50 seconds, the voltage of 1 group of storage battery groups is rapidly reduced to 198V, and the output is stopped, so that the load capacity of the group of storage battery groups is also disqualified, and the storage battery groups are also manually handled in time. The remaining 3 groups successfully complete the 5-minute load capacity test, so that the load capacity is qualified, and normal operation can be continued.

The invention has the beneficial effects that compared with the prior art:

2. The invention provides an intelligent management and control platform of a power supply module, which monitors the running state of each charging and storing integrated power supply module and realizes the on-line monitoring, intelligent management and control and alarm disposal of the power supply module. And the intelligent operation and maintenance control device can be communicated with a transformer substation monitoring background, intelligent automatic hot standby alternate replacement of a single power supply module is realized, automatic isolation of the overheat power supply module is realized, output capacity verification of an AC/DC rectifying module and load capacity test of a storage battery pack are realized. And the working power supply of the intelligent control platform is taken from a direct current bus, when an alternating current power failure occurs, the system takes electricity from the storage battery pack through the direct current bus, and the monitoring of the state of each power supply module in the screen and the receiving and storing functions of abnormal alarm information can not be lost.

The present disclosure may be a system, method, and/or computer program product. The computer program product may include a computer readable storage medium having computer readable program instructions embodied thereon for causing a processor to implement aspects of the present disclosure.

The computer readable storage medium may be a tangible device that can hold and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium would include the following: portable computer disks, hard disks, random Access Memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static Random Access Memory (SRAM), portable compact disk read-only memory (CD-ROM), digital Versatile Disks (DVD), memory sticks, floppy disks, mechanical coding devices, punch cards or in-groove structures such as punch cards or grooves having instructions stored thereon, and any suitable combination of the foregoing. Computer-readable storage media, as used herein, are not to be construed as transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., optical pulses through fiber optic cables), or electrical signals transmitted through wires.

The computer readable program instructions described herein may be downloaded from a computer readable storage medium to a respective computing/processing device or to an external computer or external storage device over a network, such as the internet, a local area network, a wide area network, and/or a wireless network. The network may include copper transmission cables, fiber optic transmissions, wireless transmissions, routers, firewalls, switches, gateway computers and/or edge servers. The network interface card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium in the respective computing/processing device.

Computer program instructions for performing the operations of the present disclosure can be assembly instructions, instruction Set Architecture (ISA) instructions, machine-related instructions, microcode, firmware instructions, state setting data, or source or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, c++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The computer readable program instructions may be executed entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computer (for example, through the Internet using an Internet service provider). In some embodiments, aspects of the present disclosure are implemented by personalizing electronic circuitry, such as programmable logic circuitry, field Programmable Gate Arrays (FPGAs), or Programmable Logic Arrays (PLAs), with state information of computer readable program instructions, which can execute the computer readable program instructions.

Finally, it should be noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that: modifications and equivalents may be made to the specific embodiments of the invention without departing from the spirit and scope of the invention, which is intended to be covered by the claims.

Claims

1. The utility model provides an operation and maintenance control method of DC power supply system, DC power supply system includes parallelly connected N+1 fills holds integration DC power supply module, the module includes charging module, storage battery branch road, BMS protection management module and electric operating switch, its characterized in that:

the operation and maintenance control method comprises the following steps:

2. The operation and maintenance control method of a dc power supply system according to claim 1, wherein:

the module fault handling, automatic isolation of the overheat power supply module, module battery charging, module hot standby, charging module carrying capacity test and storage battery carrying capacity test are performed in the following priority order:

3. The operation and maintenance control method of a dc power supply system according to claim 1, wherein:

the BMS protection management module of each module detects voltage, current and temperature data of the storage battery pack of the module, and the AC input and DC output voltage and current data of the charging module; the intelligent control platform collects the total output direct-current voltage and current data of the direct-current power supply system in real time, and the total input alternating-current voltage and current data of the direct-current power supply system; the BMS protection management module and the intelligent management and control platform of each module control the running states of the charging module, the storage battery and the electric operation switch of each module through data and instruction interaction, so that the operation and maintenance control of the direct-current power supply system is realized.

4. The operation and maintenance control method of a dc power supply system according to claim 1, wherein:

the module fault handling includes:

5. The operation and maintenance control method of a dc power supply system according to claim 1, wherein:

the module fault handling includes:

the judging mode of the fault of the charging module is as follows:

6. The operation and maintenance control method of a dc power supply system according to claim 1, wherein:

the module fault handling includes:

wherein I is _i The current value is output by the power supply module i;

X _{failure of} The number of power supply modules which are stopped by faults;

X _{hot standby} The number of power modules in the hot standby state.

7. The operation and maintenance control method of a dc power supply system according to claim 1, wherein:

the module fault handling includes:

8. The operation and maintenance control method of a dc power supply system according to claim 1, wherein:

the automatic isolation of the overheat power supply module is specifically as follows:

9. The operation and maintenance control method of a dc power supply system according to claim 1, wherein:

The module battery charging specifically comprises:

10. The operation and maintenance control method of a dc power supply system according to claim 1, wherein:

the hot standby of the module is specifically as follows:

The hot standby strategy is:

11. The operation and maintenance control method of a dc power supply system according to any one of claims 5, 8 to 10, characterized in that:

the calculation formula of the load ratio F is:

X _{failure of} The number of power supply modules which are stopped by faults;

X _{hot standby} The number of power modules in the hot standby state.

12. The operation and maintenance control method of a dc power supply system according to claim 1, wherein:

The charging module carrying capacity test is a carrying capacity test of each power module charging module which is developed regularly, each module is tested in turn, and the carrying test is not carried out when the module is in a fault, overheat and charging state;

the load capacity test process of the charging module is as follows:

13. The operation and maintenance control method of a dc power supply system according to claim 1, wherein:

the storage battery pack load capacity test is a regularly developed load capacity test of the storage battery pack of each power supply module, and all power supply modules in a normal state are tested at the same time, and when the modules are in a fault, overheat and charging state, the storage battery pack load capacity test is not performed;

14. A direct current power supply system utilizing the operation and maintenance control method according to any one of claims 1 to 13, characterized in that:

the direct current power supply system comprises N+1 direct current power supply modules which are connected in parallel, wherein the N power supply modules are used for completely matching the maximum design capacity of a charger and a storage battery of the traditional direct current power supply system, and the remaining 1 power supply modules are used as redundancy.

15. A dc power module for constructing the dc power system of claim 14, wherein:

16. The direct current power module of claim 15, wherein:

the charging module is an AC/DC rectifying module, the alternating current side of the charging module is connected with alternating current input through a breaker S, the positive electrode and the negative electrode of the direct current side are connected with the positive electrode and the negative electrode of the power storage branch in parallel, and the charging module is connected with the positive electrode and the negative electrode of the direct current bus through an electric operation switch.

17. The direct current power module of claim 15, wherein:

18. An intelligent management and control platform applied to the operation and maintenance control method in any one of claims 1 to 13, characterized in that: