CN112152245A - Charging and discharging control method and system for user side energy storage device - Google Patents

Abstract

The invention discloses a charging and discharging control method and system of a user-side energy storage device. The method includes: obtaining the total load power of the grid side; The optimal response load power is obtained; the working mode and operation parameters of the energy storage device are reset by using the difference between the total load power and the optimal response load power. The embodiment of the present invention makes the current working state of the energy storage device on the user side adapt to the actual operating state on the grid side, and can improve the auxiliary operation benefit of the energy storage device on the user side.

Description

A charging and discharging control method and system for a user-side energy storage device

technical field

The present invention relates to the field of electric power technology, and in particular, to a charging and discharging control method and system of a user-side energy storage device.

Background technique

With the deepening of power system reform and the maturity of power demand side management, the government has issued corresponding policies to encourage user-side energy storage devices to serve as demand response resources on the grid side, and promote user-side storage under the principle of combining scientificity and feasibility. The energy device participates in peak shaving and valley filling on the grid side to improve the economy of the power system and meet the user-side experience requirements. However, in view of its auxiliary operation benefit, whether the current operating state of the energy storage device on the user side can be balanced with the actual operating state on the grid side is a problem to be solved by the present invention.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies of the prior art. The present invention provides a charging and discharging control method and system for a user-side energy storage device, so that the current working state of the user-side energy storage device and the actual operating state of the grid side are balanced. It can improve the auxiliary operation benefit of the user-side energy storage device.

In order to solve the above problems, the present invention proposes a charging and discharging control method for a user-side energy storage device, the method comprising:

Obtain the total load power on the grid side;

Obtain the optimal response load power corresponding to the demand side in the current period based on the electricity price standard comparison table formulated by the grid side;

Using the difference between the total load power and the optimal response load power, the working mode and operating parameters of the energy storage device are reset.

Optionally, after obtaining the total load power on the grid side, the method further includes:

Obtain the maximum allowable capacity of the transformer on the grid side, and determine whether the total load power is greater than the maximum allowable capacity of the transformer;

After judging that the total load power is greater than the maximum allowable capacity of the transformer, controlling the energy storage device to be in a disconnected state from the grid side;

After judging that the total load power is less than or equal to the maximum allowable capacity of the transformer, the optimal response load power corresponding to the demand side in the current period is obtained based on the electricity price standard comparison table formulated by the grid side.

Optionally, the resetting of the working mode and operating parameters of the energy storage device includes:

obtaining the rated charging power and rated discharging power of the energy storage device;

Determine whether the difference is less than 0;

After judging that the difference is less than 0, the working mode of the energy storage device is set as the charging mode, and the allowable charging time corresponding to the difference is obtained based on the rated charging power.

Optionally, after judging whether the difference is less than 0, the method further includes:

After judging that the difference value is greater than or equal to 0, the working mode of the energy storage device is set as the discharge mode, and the allowable discharge duration corresponding to the difference value is obtained based on the rated discharge power.

In addition, an embodiment of the present invention also provides a charging and discharging management and control system for a user-side energy storage device, the system comprising:

The acquisition module is used to acquire the total load power on the grid side;

The response module is used to obtain the optimal response load power corresponding to the demand side in the current period based on the electricity price standard comparison table formulated by the grid side;

The setting module is configured to use the difference between the total load power and the optimal response load power to reset the working mode and operating parameters of the energy storage device.

Optionally, the system further includes:

The judgment module is used to obtain the maximum allowable capacity of the transformer on the grid side, and judge whether the total load power is greater than the maximum allowable capacity of the transformer; after judging that the total load power is greater than the maximum allowable capacity of the transformer, control the energy storage device It is disconnected from the grid side; after judging that the total load power is less than or equal to the maximum allowable capacity of the transformer, jump to the response module for execution.

Optionally, the setting module is configured to obtain the rated charging power and rated discharging power of the energy storage device; and determine whether the difference is less than 0; after judging that the difference is less than 0, set the The working mode of the energy storage device is the charging mode, and the allowable charging duration corresponding to the difference is obtained based on the rated charging power.

Optionally, the setting module is further configured to, after judging that the difference value is greater than or equal to 0, set the working mode of the energy storage device to the discharge mode, and obtain the difference value based on the rated discharge power. The corresponding allowable discharge time.

In the embodiment of the present invention, the electricity price standard comparison table is used as the adjustment benchmark of the energy storage device on the user side, and the optimal response load power of a specific area in the corresponding time period can be flexibly called, according to the total load power of the current grid side. The working mode of the user-side energy storage device is adaptively adjusted to maintain the effective coordinated control between the grid side and the user-side energy storage device, which can improve the auxiliary operation benefit of the user-side energy storage device.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a schematic structural diagram of a user-side energy storage device disclosed in an embodiment of the present invention;

2 is a schematic flowchart of a charging and discharging control method for a user-side energy storage device disclosed in an embodiment of the present invention;

3 is a schematic structural composition diagram of a charge and discharge management and control system of a user-side energy storage device disclosed in an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

FIG. 1 shows a schematic structural composition diagram of a user-side energy storage device in an embodiment of the present invention, the energy storage device includes a power distribution control module, an energy storage control module, and a control management module; wherein, the power distribution control module The module is connected to the 10kV grid-connected voltage side, the power distribution control module is connected to the 380V low voltage side, the energy storage control module is connected to the 380V low voltage side, and the power distribution control module is connected to the control The management module is connected, and the energy storage control module is connected with the control management module.

Further, the power distribution control module includes a high-voltage switchgear and a transformer, the low-voltage side of the transformer is connected to the 380V low-voltage side, and the high-voltage side of the transformer is connected to the 10kV grid through the high-voltage switchgear. The voltage side is connected, and the high-voltage switchgear is connected with the control management module. The high-voltage switchgear can cut off the electrical connection between the energy storage device and the 10kV grid-connected voltage side, and the transformer can realize the step-down function when the energy storage device performs charging work, or can The boost function is realized when the energy storage device performs discharge work.

Further, the energy storage control module includes an inverter unit, an energy storage unit and a battery management unit; the inverter unit is connected to the 380V low voltage side, and the inverter unit is connected to the energy storage unit , the energy storage unit is connected with the battery management unit, the battery management unit is connected with the control management module, and the inverter unit is connected with the control management module. Wherein, the inverter unit includes a bidirectional energy storage inverter with a model of BNSX-10KTL, which adopts a three-phase four-bridge arm structure to realize bidirectional conversion of AC voltage and DC voltage; the energy storage unit includes a capacitor C and a battery The battery assembly is connected with the inverter unit, the capacitor C is connected in parallel with both ends of the battery assembly, and the battery assembly is used to store the DC voltage output by the inverter unit or send it to the inverter unit. The inverter unit provides available DC power, and the capacitor C can filter the DC voltage delivered to the battery assembly.

Specifically, the battery management unit includes a voltage detection circuit, a Hall current sensor and a temperature sensor, and the input end of the voltage detection circuit, the input end of the Hall current sensor and the input end of the temperature sensor are respectively connected with the The battery assembly is connected, and the output end of the voltage detection circuit, the output end of the Hall current sensor and the output end of the temperature sensor are respectively connected with the control management module. The voltage value of the battery assembly can be monitored and reported in real time through the voltage detection circuit, and the charging current or discharge current of the battery assembly can be monitored and reported in real time through the Hall current sensor. The sensor can monitor and report the temperature information of the battery assembly in real time.

Further, the control and management module includes a DSP processor with a model of TMS320F2812, its operating frequency reaches 150M, and has efficient computing capabilities for each real-time information, and the DSP processor can communicate with the monitoring host through the built-in communication interface. In addition, the control and management module also includes an A/D sampling circuit connected to the input end of the DSP processor, which can monitor the voltage signal output by the voltage detection circuit, The current signal output by the Hall current sensor and the temperature signal output by the temperature sensor are sampled, and it is ensured that the three signals mentioned above have a corresponding relationship at the same time. In the implementation process, the DSP processor can use the comparison result of the current signal at the same time and the preset current threshold to determine whether the energy storage control module has faults such as overcurrent, short circuit, etc., or through the monitoring The fault removal command issued by the host, at this time, based on the connection relationship between the power distribution control module and the control management module, the on-off of the high-voltage switchgear can be remotely controlled to protect the power supply on the 10kV grid-connected voltage side. At the same time, the DSP processor can obtain the voltage signal range corresponding to the temperature signal at the same time by looking up the table, and judges that the voltage signal at the same time does not fall within the voltage signal range. , according to the power buffer command issued by the monitoring host, provide corresponding SPWM waveform and switch signal to control the inverter unit to realize the output adjustment of DC power, which is beneficial to prolong the service life of the battery assembly. In addition, the DSP processor can control the inverter unit to complete the reverse acquisition of AC power by using the battery assembly as the power supply terminal according to the power supply instruction issued by the monitoring host, which is conducive to efficient implementation Demand for peak shaving and valley filling on the grid side.

Based on the schematic structural composition of the user-side energy storage device provided in FIG. 1 , FIG. 2 shows a schematic flowchart of a charging and discharging control method for a user-side energy storage device in an embodiment of the present invention, and the method includes the following steps:

S101. Obtain the total load power on the grid side;

In the embodiment of the present invention, the load collector designated by the power company performs the collection of the total load power on the grid side, and uploads the relevant power data to the monitoring host, which is convenient for subsequent direct calls.

S102. Obtain the maximum allowable capacity of the transformer on the grid side, and determine whether the total load power is greater than the maximum allowable capacity of the transformer;

In the embodiment of the present invention, the maximum allowable capacity of the transformer can be obtained by directly reading the material information of the transformer used. The technician designs the transformer according to the normal aging temperature. If the limit temperature is exceeded, it will affect the The aging life of the transformer increases sharply, and at the same time affects the on-site use of the transformer, so it is necessary to set the maximum allowable capacity corresponding to the extreme temperature to protect the normal performance of the transformer. In the implementation process, the monitoring host will limit whether the energy storage device is safely incorporated into the grid side according to the maximum allowable capacity of the transformer, that is, by judging whether the total load power is greater than the maximum allowable capacity of the transformer, the The judgment result includes: when the total load power is greater than the maximum allowable capacity of the transformer, indicating that the energy storage device may have a safety problem during grid connection, then step S103 is performed; when the total load power is less than or equal to the When the maximum allowable capacity of the transformer is reached, it means that the energy storage device has safety conditions during the grid connection process, and then step S104 is continued.

S103, controlling the energy storage device to be in a disconnected state from the grid side;

In the embodiment of the present invention, based on the fact that the energy storage device is connected to the grid side through a high-voltage switchgear, when the monitoring host detects a safety problem, a fault removal instruction will be generated accordingly and sent to the control management module, At this time, the control and management module will control the high-voltage switchgear to disconnect according to the fault removal instruction, that is, the energy storage device does not support the grid connection function temporarily.

S104, obtaining the optimal response load power corresponding to the demand side in the current period based on the electricity price standard comparison table formulated by the grid side;

In the embodiment of the present invention, electric power personnel perform integrated benefit analysis and power consumption planning according to the daily electricity consumption and monthly electricity bills paid by the user side in the past two years. The adjusted electricity price is used to formulate the response electricity consumption in different time periods for the user side, so as to form the electricity price standard comparison table, which can be used by relevant staff to call the electricity consumption side in a certain area corresponding to the current time period. The optimal response load power, that is, the optimal load power allowed to be used by the user side in the current time period, is used as a comparison standard for setting the working mode and operating parameters of the energy storage device.

S105 , using the difference between the total load power and the optimal response load power to reset the working mode and operating parameters of the energy storage device.

In the embodiment of the present invention, the rated charging power and rated discharging power of the energy storage device are obtained by querying various system parameters of the used battery components preferentially. Generally speaking, due to the thermal safety of the battery components during the discharge phase The risk is small, so the rated charging power will be lower than the rated discharging power; secondly, the difference between the total load power minus the optimal response load power is obtained, and it is judged whether the difference is less than 0, and the judgment result includes :

(1) When the difference is less than 0, it means that the current grid side is in the power consumption relaxation period, the monitoring host will set the working mode of the energy storage device to the charging mode, and generate a power buffer based on the difference The instruction is sent to the control management module, and at the same time, the control management module will obtain the current remaining capacity value of the energy storage device by dividing the rated charging power and the currently collected voltage signal; At this time, the control and management module will parse out the difference according to the received power buffer command and convert it into the corresponding charging amount, and then extract the difference from the current remaining capacity value and the charging amount. Obtain the minimum value, and finally obtain the allowable charging duration of the energy storage device by dividing the minimum value with the current signal currently collected;

(2) When the difference value is greater than or equal to 0, it means that the current grid side is in a period of power shortage, and the monitoring host will set the working mode of the energy storage device to the discharge mode, and generate electricity based on the difference value The supply instruction is issued to the control management module, and at the same time the control management module obtains the current remaining capacity value of the energy storage device based on the calculation method mentioned in (1); at this time, the control management module will The received power supply command parses the difference and converts it into the corresponding discharge amount, and then obtains the minimum value from the current remaining capacity value and the discharge amount, and finally passes the The allowable discharge duration of the energy storage device is obtained by dividing the minimum value with the currently collected current signal.

FIG. 3 shows a schematic structural composition diagram of a charging and discharging management and control system of a user-side energy storage device in an embodiment of the present invention, where the system includes:

an obtaining module 201, configured to obtain the total load power on the grid side;

The judgment module 202 is used to obtain the maximum allowable capacity of the transformer on the grid side, and judge whether the total load power is greater than the maximum allowable capacity of the transformer; after judging that the total load power is greater than the maximum allowable capacity of the transformer, control the energy storage The device is in a disconnected state from the grid side; after judging that the total load power is less than or equal to the maximum allowable capacity of the transformer, jump to the response module 203 for execution.

The response module 203 is configured to obtain the optimal response load power corresponding to the demand side in the current period based on the electricity price standard comparison table formulated by the grid side;

The setting module 204 is configured to use the difference between the total load power and the optimal response load power to reset the operation mode and operation parameters of the energy storage device.

Specifically, the setting module 204 is configured to obtain the rated charging power and rated discharging power of the energy storage device; and determine whether the difference is less than 0; after judging that the difference is less than 0, set the The working mode of the energy storage device is the charging mode, and the allowable charging duration corresponding to the difference is obtained based on the rated charging power. In addition, the setting module 204 is further configured to set the working mode of the energy storage device to the discharge mode after judging that the difference is greater than or equal to 0, and obtain the corresponding value of the difference based on the rated discharge power allowable discharge time.

Wherein, the system is configured to execute the above-mentioned charging and discharging control method of the user-side energy storage device. For the specific implementation of each module in the system, please refer to the above-mentioned embodiments, which will not be repeated here.

In the embodiment of the present invention, the electricity price standard comparison table is used as the adjustment benchmark of the energy storage device on the user side, and the optimal response load power of a specific area in the corresponding time period can be flexibly called, according to the total load power of the current grid side. The working mode of the user-side energy storage device is adaptively adjusted to maintain the effective coordinated control between the grid side and the user-side energy storage device, which can improve the auxiliary operation benefit of the user-side energy storage device.

Those of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium, and the storage medium can include: Read Only Memory (ROM, Read Only Memory), Random Access Memory (RAM, Random Access Memory), magnetic disk or optical disk, etc.

The charging and discharging control method and system for a user-side energy storage device provided by the embodiments of the present invention have been described above in detail. The principles and implementations of the present invention are described with specific examples in this paper. The description of the above embodiments It is only used to help understand the method of the present invention and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific embodiments and application scope. In summary, The contents of this specification should not be construed as limiting the present invention.

Claims (8)

1. A charging and discharging control method for a user-side energy storage device, wherein the method comprises: Obtain the total load power on the grid side; Obtain the optimal response load power corresponding to the demand side in the current period based on the electricity price standard comparison table formulated by the grid side; Using the difference between the total load power and the optimal response load power, the working mode and operating parameters of the energy storage device are reset. 2 . The charging and discharging control method of a user-side energy storage device according to claim 1 , wherein after acquiring the total load power on the grid side, the method further comprises: 3 . Obtain the maximum allowable capacity of the transformer on the grid side, and determine whether the total load power is greater than the maximum allowable capacity of the transformer; After judging that the total load power is greater than the maximum allowable capacity of the transformer, controlling the energy storage device to be in a disconnected state from the grid side; After judging that the total load power is less than or equal to the maximum allowable capacity of the transformer, the optimal response load power corresponding to the demand side in the current period is obtained based on the electricity price standard comparison table formulated by the grid side. 3 . The charging and discharging control method of a user-side energy storage device according to claim 1 , wherein the resetting of the working mode and operation parameters of the energy storage device comprises: 3 . obtaining the rated charging power and rated discharging power of the energy storage device; Determine whether the difference is less than 0; After judging that the difference is less than 0, the working mode of the energy storage device is set as the charging mode, and the allowable charging time corresponding to the difference is obtained based on the rated charging power. 4 . The charging and discharging control method of the user-side energy storage device according to claim 3 , wherein after judging whether the difference is less than 0, the method further comprises: 5 . After judging that the difference value is greater than or equal to 0, the working mode of the energy storage device is set as the discharge mode, and the allowable discharge duration corresponding to the difference value is obtained based on the rated discharge power. 5. A charging and discharging management and control system for a user-side energy storage device, wherein the system comprises: The acquisition module is used to acquire the total load power on the grid side; The response module is used to obtain the optimal response load power corresponding to the demand side in the current period based on the electricity price standard comparison table formulated by the grid side; The setting module is configured to use the difference between the total load power and the optimal response load power to reset the working mode and operating parameters of the energy storage device. 6 . The charging and discharging management and control system of the user-side energy storage device according to claim 5 , wherein the system further comprises: The judgment module is used to obtain the maximum allowable capacity of the transformer on the grid side, and judge whether the total load power is greater than the maximum allowable capacity of the transformer; after judging that the total load power is greater than the maximum allowable capacity of the transformer, control the energy storage device It is disconnected from the grid side; after judging that the total load power is less than or equal to the maximum allowable capacity of the transformer, jump to the response module for execution. 7 . The charging and discharging control system of a user-side energy storage device according to claim 5 , wherein the setting module is used to obtain the rated charging power and rated discharging power of the energy storage device; Whether the difference is less than 0; after judging that the difference is less than 0, set the working mode of the energy storage device to the charging mode, and obtain the allowable charging duration corresponding to the difference based on the rated charging power. 8 . The charging and discharging control system of the user-side energy storage device according to claim 7 , wherein the setting module is further configured to set the energy storage device after judging that the difference value is greater than or equal to 0. 9 . The working mode of the device is the discharge mode, and the allowable discharge duration corresponding to the difference is obtained based on the rated discharge power.

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