Balanced control method and strategy for chain type energy storage system

Abstract

The invention discloses an equalization control method and strategy for a chain type energy storage system, and the method comprises the following steps: calculating a difference value between a charge state average value of a three-phase current conversion chain and a charge state average value of each phase current conversion chain, and obtaining a charge state difference value of each phase current conversion chain; calculating the product of the charge state difference value of each phase of the current conversion chain, the charge state balance coefficient between the current conversion chains and the absolute value of the active power reference value of the corresponding current conversion chain to obtain a superposed active power reference value of each phase of the current conversion chain; superposing the superposed active power reference value to a corresponding current conversion chain active power reference value to obtain an active power final reference value of each phase of current conversion chain; calculating an active current reference value of each phase of current conversion chain according to the active power final reference value of each phase of current conversion chain; and adjusting the instantaneous current of each phase of current conversion chain according to the active current reference value of each phase of current conversion chain. According to the invention, state-of-charge balance control in the chain type energy storage system can be realized, and overmodulation is avoided at the same time.

Description

technical field [0001] The invention belongs to the field of energy storage and reactive power compensation system control, and particularly relates to a balance control method and strategy of a chain energy storage system. Background technique [0002] After large-scale new energy is connected to the AC power grid, due to the randomness and volatility of wind energy and solar energy, as well as the characteristics of no inertia and weak damping of wind power and photovoltaic units, it will cause large power and frequency disturbances to the power grid; The interaction between the generator and the power grid will lead to emerging stability problems such as broadband oscillation, resulting in unit tripping and even equipment damage, endangering the safe and stable operation of the power grid. In order to solve the above problems, the configuration of reactive power compensation devices and large-scale energy storage devices in large-scale new energy stations has become the n...

AI Technical Summary

Problems solved by technology

[0002] After large-scale new energy is connected to the AC grid, due to the randomness and volatility of wind energy and solar energy, as well as the characteristics of no inertia and weak damping of wind power and photovoltaic units, it will cause large power and frequency disturbances to the grid; The interaction between the inverter and the power grid will lead to emerging stability problems such as broadband oscillation, causing unit trips and even equipment damage, endangering the safe and stable operation of the power grid

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