A control method and system for primary frequency regulation of power grid based on battery energy storage power supply

Abstract

The invention discloses a power grid primary frequency modulation control method based on battery energy-storage power source and a system thereof. A grid frequency is monitored in real time; a grid frequency deviation absolute value is calculated in real time based on a rated value of the grid frequency; if the grid frequency deviation absolute value is greater than or equal to a preset grid frequency stability threshold, an output model of an energy-storage power source is determined based on a grid frequency deviation change rate; and when the grid frequency deviation absolute value is stabilized to be a steady-state frequency deviation value, frequency modulation end is completed. According to the invention, the corresponding output model of the energy-storage power source is designedbased on a disturbance type design; and the effect of the primary frequency modulation is improved, the capacity configuration of the energy-storage power source is reduced, and the service life of the energy-storage power source is prolonged.

Description

technical field [0001] The invention belongs to the field of power grid control, and in particular relates to a primary frequency modulation control method and system for a power grid based on a battery energy storage power supply. Background technique [0002] In the primary frequency regulation of the power grid, each unit changes its output according to its own frequency static characteristics to realize frequency difference regulation, which is generally used to adjust the load fluctuation of the second level. When the frequency of the power grid changes, the rotational energy stored in the system load will change to prevent the change of the system frequency. In addition, the speed of all the generator sets in the system will also change, and the governor of the generator set will act to adjust the prime mover power, in order to improve the imbalance between prime mover power and load power. However, the generator has the ability to participate in primary frequency reg...

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Problems solved by technology

However, the energy storage power supply participates in frequency modulation, and the control strategy is a difficult point

When the energy storage power supply participates in the primary frequency regulation of the power grid, the existing control modes include virtual inertia and virtual droop. The existing control strategy in the process of primary frequency regulation is generally a single frequency regulation mode, and the characteristics of these two frequency regulation models and their use in The advantages of different frequency modulation stages are different, so a single frequency modulation mode is difficult to meet the actual needs, and the frequency modulation effect needs to be further improved; CN201711074813.5 discloses "a control method for battery energy storage power supply participating in the primary frequency modulation of the power grid", a method of synthesizing the frequency at the same time There are two methods of frequency modulation mode, but there are two main problems in this method. Since the frequency deviation in the inertial response phase is continuously increasing, it is essentially impossible to accurately obtain the maximum frequency deviation value in the inertial response phase. The design in this scheme The empirical value of the maximum frequency deviation that the power grid can withstand, but there is an error between it and the actual maximum frequency deviation, and this error will lead to the inability to achieve the best frequency modulation effect; the second is caused by the different types of disturbances in the power grid The characteristics of the frequency deviation are also different. For example, if the disturbance is a continuous disturbance with little fluctuation, the duration of the inertial response phase and the drooping response phase in the frequency modulation process of this disturbance is very short, and the two phases are not too obvious The limit or the two stages change very quickly, it is actually difficult to accurately control the frequency modulation method of this method, and it does not take into account the service life of the energy storage power supply

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