Thermal power generating unit energy storage auxiliary frequency modulation system

Abstract

The utility model provides an energy storage auxiliary frequency modulation system of a thermal power generating unit, which comprises at least one main transformer used for connecting auxiliary power and a power grid side; the at least two high-voltage station transformers are used for providing power for normal operation of the unit; the at least two sets of energy storage devices are connected with the high-voltage station transformer and are used for assisting the unit to participate in primary frequency modulation and secondary frequency modulation; the system mainly comprises an energy storage control system matched with an energy storage device, the energy storage control system comprises a signal distribution module, a signal analysis module, an energy storage control module, an energy storage state monitoring module and an event recording module, and the effects of balancing battery energy storage capacity attenuation and power system frequency stability are achieved; power plant segmented buses are included; a plurality of circuit breakers; and a plurality of DC / AC inverters. The utility model has the advantages that the standby capacity of the frequency modulation system can be increased, and the service life of the battery energy storage system is prolonged while the frequency deviation of the power system is quickly recovered to a rated value.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage and frequency modulation of thermal power generation units, in particular to an energy storage auxiliary frequency modulation system of a thermal power generation unit. Background Art

[0002] Frequency is an important parameter used to describe the power quality of power systems. Frequency adjustment is a key link in achieving stable operation of power systems. It mainly adjusts the active power generated by generators to maintain the stability of the power system frequency. When the system frequency fluctuates, daily production and life will be seriously affected. Modern power systems usually use an automatic generation control (AGC) system for frequency regulation. The system can monitor frequency changes in real time and automatically adjust the output power of the generator to maintain frequency stability. In addition, with the widespread application of renewable energy, the difficulty of power system frequency regulation is gradually increasing, so more advanced frequency regulation resources and strategies are needed to meet the challenges.

[0003] With the large-scale access of renewable energy, the stability of the power system has become increasingly prominent. Energy storage technology, with its fast response and high regulation accuracy, provides a new solution for auxiliary frequency regulation of the power system. By properly configuring energy storage devices, power fluctuations can be effectively smoothed and the stability of the power system can be improved. The participation of energy storage technology in auxiliary frequency regulation of the power system is of great significance for ensuring the stable operation of the power system and promoting the development of renewable energy.

[0004] At present, there is a certain practical foundation for the domestic thermal power unit energy storage combined frequency regulation project. There are existing energy storage assisted frequency regulation pilot bases such as Zhuhai and Shanxi, and the overall operation effect is good, but the system solution still has room for optimization. At present, domestic energy storage participation in frequency regulation is mostly based on the stability of power system frequency. The capacity attenuation of the battery energy storage system is ignored, and the relationship between battery life and power system frequency cannot be well balanced. Utility Model Content

[0005] In view of this, the purpose of the utility model is to provide a thermal power unit energy storage auxiliary frequency regulation system, provide a system model in which energy storage participates in auxiliary frequency regulation, and increase the frequency stability of the system; provide an energy storage control module, which effectively reduces the capacity attenuation of the battery energy storage unit and improves the economic benefits of the power system operation.

[0006] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a thermal power unit energy storage auxiliary frequency modulation system, including a 220KV bus, a main transformer, a generator, a first high-voltage transformer, a second high-voltage transformer, n first energy storage box transformers, n second energy storage box transformers, a first battery energy storage system, a second battery energy storage system, a first bus section A, a first bus section B, a second bus, a third bus section A, a third bus section B, a fourth bus, a plurality of bus tie circuit breakers, and a plurality of energy storage switches;

[0007] The first battery energy storage system is connected to the second plant high-voltage busbar via an energy storage box transformer and an energy storage switch;

[0008] The second battery energy storage system is connected to the fourth plant high-voltage busbar via an energy storage box transformer and an energy storage switch;

[0009] The second high-voltage busbar for auxiliary use is connected to section A of the first busbar through the fifth bus tie circuit breaker and the first incoming line circuit breaker;

[0010] The second auxiliary high-voltage busbar is connected to section A of the third busbar via the fourth busbar tie breaker and the second busbar tie breaker;

[0011] The fourth high-voltage busbar for auxiliary use is connected to the first busbar section B through the first busbar tie breaker and the third busbar tie breaker;

[0012] The fourth high-voltage busbar for auxiliary use is connected to the third busbar section B through the sixth bus tie circuit breaker and the second incoming line circuit breaker;

[0013] The first high-voltage transformer is connected to the first busbar section A through the first plant circuit breaker;

[0014] The first high-voltage transformer is connected to the first busbar section B through the second transformer circuit breaker;

[0015] The second high-voltage transformer is connected to the third busbar section A through the third plant circuit breaker;

[0016] The second high-voltage transformer is connected to the third busbar section B through the fourth plant circuit breaker;

[0017] The main transformer is connected to the 220KV busbar through a first grid-connected switch and a second grid-connected switch.

[0018] In a preferred embodiment:

[0019] The first busbar section A, the first busbar section B, the second busbar, the third busbar section A, the third busbar section B, and the fourth busbar are all 6.6KV busbars.

[0020] In a preferred embodiment:

[0021] A plurality of battery energy storage units constitute a battery energy storage system, and each of the battery energy storage units is provided with a battery energy storage box transformer;

[0022] The battery energy storage system is connected to the plant high-voltage bus through the energy storage box transformer.

[0023] In a preferred embodiment:

[0024] The first battery energy storage system and the second battery energy storage system both include: an energy storage system converter cabinet, a DC / AC converter, an energy storage control system, and a battery energy storage unit; wherein:

[0025] The energy storage system converter cabinet is used for voltage conversion of battery energy storage output energy into the grid;

[0026] The DC / AC converter is used for converting the DC output of the battery energy storage into AC;

[0027] The energy storage control system is used to control the output of the energy storage unit;

[0028] The battery energy storage unit is used to provide fast and stable energy output.

[0029] In a preferred embodiment, the energy storage control system comprises: a signal distribution module, a signal analysis module, an energy storage control module, a battery energy storage unit, an energy storage status monitoring module, an event recording module, and a DCS system;

[0030] The signal distribution module distributes the issued power generation indicators to the thermal power units and the battery energy storage system in the form of signals, so as to adjust the power generation behaviors of different energy supply units;

[0031] The signal analysis module is used to analyze the power generation indicators allocated to the battery energy storage system, including the power system frequency indicators;

[0032] The energy storage control module is used to receive the state information of the battery energy storage transmitted by the energy storage state monitoring module, and is used to receive the power generation signal information allocated to the battery energy storage, and controls the charge and discharge behavior of the battery energy storage unit in combination with the capacity decay characteristics of the battery energy storage and the above-mentioned battery energy storage state and characteristics, including controlling the current and voltage of the battery energy storage unit during charge and discharge;

[0033] The battery energy storage unit provides active support for the frequency stability of the power system;

[0034] The energy storage status monitoring module is used to monitor the operating status of the battery energy storage system, specifically including the operating current and voltage of the battery energy storage system during operation, the operating temperature of the battery energy storage system, the depth of battery energy storage charge and discharge, and the charge status of the battery energy storage system. The charge status information of the monitored battery energy storage unit is transmitted to the energy storage control module, which is an important indicator for subsequent judgment of whether the battery energy storage is in operation;

[0035] The event recording module is used to receive and save the charging and discharging behaviors of the battery energy storage unit, record the charging and discharging current and voltage of each battery energy storage unit, and record the fault conditions of the battery energy storage unit for reference during subsequent maintenance;

[0036] The DCS system is used to control and check the operating status of the battery energy storage system and receive alarm information of the battery energy storage for display, and control of the battery energy storage unit is achieved through the system.

[0037] Compared with the prior art, the utility model has the following beneficial effects:

[0038] (1) The utility model provides a thermal power unit energy storage assisted frequency regulation system, which provides a specific system for the power system to participate in the frequency regulation of energy storage assistance, and can effectively give play to the characteristics of rapid discharge of the energy storage system, so that the frequency of the system that exceeds the limit can be quickly restored to the set value;

[0039] (2) The utility model provides a thermal power unit energy storage auxiliary frequency regulation system, which fully considers the capacity decay characteristics of the battery energy storage system and involves an energy storage control module, which can effectively reduce the capacity decay of the battery energy storage system and maintain the balance between the frequency stability of the power system and the capacity decay of the battery energy storage system;

[0040] (3) The utility model provides a thermal power unit energy storage auxiliary frequency regulation system, which effectively maintains the system frequency stability through the rapid response of the energy storage system, reduces the operating cost of the entire system, and enhances the economic benefits of the system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic diagram of the structure of a frequency modulation system based on energy storage according to a preferred embodiment of the utility model;

[0042] Figure 2 This is a structural block diagram of the energy storage control module of the preferred embodiment of the utility model. DETAILED DESCRIPTION

[0043] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0044] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0045] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application; as used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations.

[0046] A thermal power unit energy storage auxiliary frequency regulation system, reference Figure 1-2 , including 220KV bus, main transformer, generator, 1# high-voltage transformer, 2# high-voltage transformer, 11# energy storage box transformer...1n# energy storage box transformer, 21# energy storage box transformer...2n# energy storage box transformer, 1# battery energy storage system, 2# battery energy storage system, 1# bus section A, 1# bus section B, 2# bus, 3# bus section A, 3# bus section B, 4# bus, multiple bus tie circuit breakers, and multiple energy storage switches;

[0047] The 1# battery energy storage system is connected to the 2# plant high-voltage busbar via an energy storage box transformer and an energy storage switch;

[0048] The 2# battery energy storage system is connected to the 4# plant high-voltage busbar via an energy storage box transformer and an energy storage switch;

[0049] The 2# plant high-voltage busbar is connected to the 1# busbar section A through the 5# bus tie circuit breaker and the 1# incoming line circuit breaker;

[0050] The 2# plant high-voltage busbar is connected to the 3# busbar section A through the 4# busbar tie breaker and the 2# busbar tie breaker;

[0051] The 4# plant high-voltage busbar is connected to the 1# busbar section B through the 1# busbar tie breaker and the 3# busbar tie breaker;

[0052] The 4# plant high-voltage busbar is connected to the 3# busbar section B through the 6# bus tie circuit breaker and the 2# incoming line circuit breaker;

[0053] The 1# high-voltage transformer is connected to the 1# busbar section A through the 1# plant circuit breaker;

[0054] The 1# high-voltage transformer is connected to the 1# busbar section B through the 2# plant circuit breaker;

[0055] The 2# high-voltage transformer is connected to the 3# busbar section A through the 3# plant circuit breaker;

[0056] The 2# high-voltage transformer is connected to the 3# busbar section B through the 4# plant circuit breaker;

[0057] The main transformer is connected to the 220KV busbar through 1# and 2# grid-connected switches.

[0058] After completing the construction of the above system, the battery energy storage system is described below:

[0059] The battery energy storage system comprises: an energy storage system converter cabinet, a DC / AC converter, an energy storage control system, and a battery energy storage unit; wherein:

[0060] The energy storage system converter cabinet is used for voltage conversion of battery energy storage output energy into the grid;

[0061] The DC / AC converter realizes the conversion between direct current and alternating current output by the battery energy storage;

[0062] The energy storage control system is used to control the output of the energy storage unit and achieve a balance between the frequency stability of the power system and the service life of the battery energy storage unit;

[0063] The battery energy storage unit is used to provide fast and stable energy output.

[0064] After completing the construction of the above battery energy storage system, the following Figure 2 Describe the energy storage control system, which includes: a signal distribution module, a signal analysis module, an energy storage control module, a battery energy storage unit, an energy storage status monitoring module, an event recording module, and a DCS system;

[0065] The signal distribution module distributes the issued power generation indicators to the thermal power units and the battery energy storage system in the form of signals, so as to adjust the power generation behaviors of different energy supply units and maintain the frequency stability of the power system;

[0066] The signal analysis module is used to analyze the power generation indicators allocated to the battery energy storage system, mainly including indicators such as the power system frequency;

[0067] The energy storage control module is used to receive the battery energy storage state information transmitted by the energy storage state monitoring module, and is used to receive the power generation signal information allocated to the battery energy storage, and in combination with the capacity decay characteristics of the battery energy storage, in combination with the above-mentioned battery energy storage state and characteristics, controls the charge and discharge behavior of the battery energy storage unit, including controlling the current and voltage of the battery energy storage unit during charge and discharge;

[0068] The battery energy storage unit provides active support for the frequency stability of the power system;

[0069] The energy storage status monitoring module is used to monitor the operating status of the battery energy storage system, specifically including the operating current and voltage of the battery energy storage system during operation, the operating temperature of the battery energy storage system, the depth of battery energy storage charge and discharge, and the charge status of the battery energy storage system. The charge status information of the monitored battery energy storage unit is transmitted to the energy storage control module, which is used as an important indicator for subsequent judgment of whether the battery energy storage is in operation;

[0070] The event recording module is used to receive and save the charging and discharging behaviors of the battery energy storage unit, record the charging and discharging current and voltage of each battery energy storage unit, and record the fault conditions of the battery energy storage unit for reference during subsequent maintenance;

[0071] The DCS system is used to control and check the operating status of the battery energy storage system and receive alarm information of the battery energy storage for display, and control of the battery energy storage unit is achieved through the system.

[0072] The specific implementation methods between the modules are as follows:

[0073] The received power generation control signal is distributed to the thermal power unit and the battery energy storage system through the signal distribution module to provide an output power reference for the power generation equipment; the output power reference signal distributed to the battery energy storage system is analyzed by the signal analysis module to obtain signals including but not limited to the output power index and the power system frequency deviation signal, and the above two signals are input into the energy storage control module to control the action of the battery energy storage unit; the energy storage status monitoring module is used to monitor the operating status of the battery energy storage unit in real time, including but not limited to the charging and discharging current and voltage of the battery energy storage unit, the internal temperature of the battery energy storage unit, and the real-time charge status of the battery energy storage, and the above status information is transmitted to the energy storage control module; the energy storage control module determines the action of the battery energy storage unit by analyzing the information transmitted by the signal analysis module and the energy storage status monitoring module, specifically:

[0074] In order to reduce the capacity attenuation of the battery energy storage unit and improve the economic benefits of the battery energy storage unit, the frequency action value related to the action is set for the battery energy storage unit, so that the battery energy storage unit can only output active power when the frequency exceeds the limit and the battery energy storage unit meets the action value;

[0075] According to the operation of the battery energy storage unit, the energy storage status is updated in real time, the accuracy of information transmission between the battery energy storage control module and the energy storage status monitoring module is improved, and the monitored energy storage status information is transmitted to the DCS system in real time through wired communication to achieve human intervention in the operation of the energy storage unit; finally, the operation of the battery energy storage unit is recorded through the event recording module, and the corresponding log is generated to provide information for subsequent reference.

[0076] It should be emphasized that the execution program involved in the present utility model is an existing or known program. It should be understood that the present application is a combination innovation and is not limited to known devices, units, module hardware structures, and existing known programs inside. That is, existing hardware devices with corresponding execution functions are used in the present utility model.

Claims

1. A thermal power unit energy storage auxiliary frequency modulation system, characterized in that: Including 220KV bus, main transformer, generator, first high-voltage transformer, second high-voltage transformer, n first energy storage box transformers, n second energy storage box transformers, first battery energy storage system, second battery energy storage system, first bus section A, first bus section B, second bus, third bus section A, third bus section B, fourth bus, multiple bus tie circuit breakers, multiple energy storage switches; The first battery energy storage system is connected to the second plant high-voltage busbar via an energy storage box transformer and an energy storage switch; The second battery energy storage system is connected to the fourth plant high-voltage busbar via an energy storage box transformer and an energy storage switch; The second high-voltage busbar for auxiliary use is connected to section A of the first busbar through the fifth bus tie circuit breaker and the first incoming line circuit breaker; The second auxiliary high-voltage busbar is connected to section A of the third busbar via the fourth busbar tie breaker and the second busbar tie breaker; The fourth high-voltage busbar for auxiliary use is connected to the first busbar section B through the first busbar tie breaker and the third busbar tie breaker; The fourth high-voltage busbar for auxiliary use is connected to the third busbar section B through the sixth bus tie circuit breaker and the second incoming line circuit breaker; The first high-voltage transformer is connected to the first busbar section A through the first plant circuit breaker; The first high-voltage transformer is connected to the first busbar section B through the second transformer circuit breaker; The second high-voltage transformer is connected to the third busbar section A through the third plant circuit breaker; The second high-voltage transformer is connected to the third busbar section B through the fourth plant circuit breaker; The main transformer is connected to the 220KV busbar through a first grid-connected switch and a second grid-connected switch.

2. The energy storage auxiliary frequency modulation system of a thermal power unit according to claim 1, characterized in that: The first busbar section A, the first busbar section B, the second busbar, the third busbar section A, the third busbar section B, and the fourth busbar are all 6.6KV busbars.

3. The energy storage auxiliary frequency modulation system of a thermal power unit according to claim 1, characterized in that: A plurality of battery energy storage units constitute a battery energy storage system, and each of the battery energy storage units is provided with a battery energy storage box transformer; The battery energy storage system is connected to the plant high-voltage bus through the energy storage box transformer.

4. The energy storage auxiliary frequency modulation system of a thermal power unit according to claim 1, characterized in that: The first battery energy storage system and the second battery energy storage system both include: an energy storage system converter cabinet, a DC / AC converter, an energy storage control system, and a battery energy storage unit; wherein: The energy storage system converter cabinet is used for voltage conversion of battery energy storage output energy into the grid; The DC / AC converter is used for converting the DC output of the battery energy storage into AC; The energy storage control system is used to control the output of the energy storage unit; The battery energy storage unit is used to provide fast and stable energy output.

5. The energy storage auxiliary frequency modulation system of a thermal power unit according to claim 4, characterized in that: The energy storage control system comprises: a signal distribution module, a signal analysis module, an energy storage control module, a battery energy storage unit, an energy storage status monitoring module, an event recording module, and a DCS system; The signal distribution module distributes the issued power generation indicators to the thermal power units and the battery energy storage system in the form of signals, so as to adjust the power generation behaviors of different energy supply units; The signal analysis module is used to analyze the power generation indicators allocated to the battery energy storage system, including the power system frequency indicators; The energy storage control module is used to receive the battery energy storage state information transmitted by the energy storage state monitoring module, and is used to receive the power generation signal information allocated to the battery energy storage, and in combination with the capacity decay characteristics of the battery energy storage, in combination with the above-mentioned battery energy storage state and characteristics, controls the charge and discharge behavior of the battery energy storage unit, including controlling the current and voltage of the battery energy storage unit during charge and discharge; The battery energy storage unit provides active support for the frequency stability of the power system; The energy storage status monitoring module is used to monitor the operating status of the battery energy storage system, specifically including the operating current and voltage of the battery energy storage system during operation, the operating temperature of the battery energy storage system, the depth of battery energy storage charge and discharge, and the charge status of the battery energy storage system. The charge status information of the monitored battery energy storage unit is transmitted to the energy storage control module, which is an important indicator for subsequent judgment of whether the battery energy storage is in operation; The event recording module is used to receive and save the charging and discharging behaviors of the battery energy storage unit, record the charging and discharging current and voltage of each battery energy storage unit, and record the fault conditions of the battery energy storage unit for reference during subsequent maintenance; The DCS system is used to control and check the operating status of the battery energy storage system and receive alarm information of the battery energy storage for display, and control of the battery energy storage unit is achieved through the system.

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