2094-BC01-M01-M Analyze the energy storage system in normal mode

For this mode, it is a common working mode, at this time the remaining capacity of the battery and the supercapacitor are maintained in a normal state, but because the solar and wind power generation modes used in the new energy power generation system are intermittent, the actual operation is prone to sudden local load reduction or increase. When this happens, it will inevitably lead to high-frequency fluctuations in the output power of the power generation system. At the same time, because the battery device needs a long time to complete the charging or discharge process, it is difficult to effectively control such high-frequency fluctuations in a timely manner. Therefore, it is necessary to make full use of supercapacitors to control this part of the fluctuating power. In addition, when the distributed new energy generation and energy storage system is operating under isolated island conditions or grid-connected state, the power in the energy storage system can also be rationally configured by the above energy management strategy, and the actual power required can be generated according to the actual operation situation. At the same time, the power output of two energy storage devices, the supercapacitor and the battery, can be effectively distributed by reasonably adjusting the gain K. For example, when the supercapacitor has a large remaining capacity, the gain K can be increased accordingly, so that the supercapacitor can bear more power output.

4.2 Analyzing battery abnormal Modes

The situation in the abnormal mode of the battery is mainly manifested as that the remaining capacity of the battery energy storage device is in a relatively low or relatively high state, while the remaining capacity of the super capacitor device is always in a normal state. In this case, the safety and stability of the overall power grid system will be greatly re2094-BC01-M01-M duced. Therefore, in order to ensure the normal operation of the system, the system is restored to the normal working mode in a very short time. At the same time, when the energy storage system in distributed power generation is in the grid-connected state, its actual operating state will be close to the abnormal mode of battery capacitance, at this time, in order to restore the remaining capacity of the battery device itself as soon as possible, the internal and external power grid energy exchange method is used to truly ensure the normal operation of the system. During this process, there may be a certain power shock, but the actual impact on the system is not obvious. In addition, during the actual operation of the energy storage system in the isolated island state, due to certain limitations in the energy storage state of the supercapacitor device itself, it is difficult to promote the battery device to return to the normal working state in a short time by means of energy transfer. In this case, you can only use the super capacitor to ensure the effective transfer of energy, until the grid connection is successful, you can then charge the battery device, so as to ensure that it can return to the normal operating state.

4.3 Analyzing the ultracapacitor Exception Mode

For the ultracapacitor abnormal mode, the abnormal situation shown is mainly that the remaining capacity of the2094-BC01-M01-M battery energy storage device is in normal condition, while the remaining capacity of the ultracapacitor energy storage device will be high or relatively low abnormal. In this case, the performance of the distributed generation energy storage system itself will be reduced, such as its absorption and release of high-frequency power performance, and in serious cases, it will bring serious negative effects on the corresponding functions of the overall system. Restore the system to the normal working mode in time. At the same time, when the energy storage system in the distributed new energy generation is in the grid-connected state, the external power grid can be regarded as an unlimited power grid connection, in this case, the supercapacitor can use the way of energy transmission to transfer the energy beyond its own to the external power grid, so as to promote itself to return to the normal operating state in a short time. In addition, in the isolated island state, during the operation of the energy storage system, due to the lack of corresponding auxiliary support provided by the external power grid, it should be fully ensured that the energy storage system has been maintained in power balance

Stable state, through the super capacitor to effectively enhance the system’s own reaction force. At the same time, in order to ensure the effective improvement of the stability of the output power of distributed new energy generation, the energy transfer between the supercapacitor and the battery is also strengthened, so as to effectively achieve the purpose of effective energy management.

4.4 Analyzing All Exception Modes

For the energy storage management strategy under all abnormal mode states, it is necessary to integrate the above several abnormal conditions, through the mutual balance between DC bus bars, so that the abnormal mode can be reasonably transformed into one of the above modes, and then adopt the corresponding management strategy for control. For the energy management strategy in abnormal mode, it can be divided into the following two cases: First, the remaining capacity of the battery and the supercapacitor are too high, at this time, it is necessary to control its own output power during the operation of the island; Second, for both the remaining capacity of the battery and the super capacitor are in a too low state, in order to effectively maintain the sensitive load is always in a normal state, some unnecessary loads are eliminated, so as to fully ensure that the distributed new energy power generation system is in a stable state.