And stable operation of direct-current bus voltage is ensured

Abstract

The invention provides a control method for ensuring stable operation of direct-current bus voltage. The method comprises the following steps: S1, determining a voltage deviation value of a direct-current bus in a direct-current distribution network; S 2, determining a voltage reference value of a voltage source converter in the DC distribution network; S 3, determining a PWM driving signal for controlling the converter to work; and inputting the actual measurement value of the direct-current side voltage of the voltage source converter and the direct-current side reference voltage of the voltage source converter into a double-loop control system to obtain a PWM driving signal. According to the control method for ensuring the stable operation of the direct-current bus voltage, the proportionality coefficient of the direct-current side outlet current of each converter in the system operation process can be effectively optimized, the stable operation of the direct-current bus voltage isensured, and the control accuracy is improved.

Description

technical field [0001] The invention relates to the technical field of operation control of a direct current distribution network, in particular to a control method for ensuring stable operation of a direct current bus voltage. Background technique [0002] Due to the continuous depletion of primary fossil energy and increasing environmental concerns worldwide, the power and energy industry is moving towards renewable clean energy, energy storage units and modern load integration by building within the traditional AC grid infrastructure Flexible and efficient multi-terminal DC distribution network. Among them, the DC bus voltage is an important factor to measure the stability of the DC distribution network and the rational distribution of power, and the research on its control method has practical and academic significance. The most widely used method to control the stable operation of the DC bus voltage is the DC droop control, which is proposed on the basis of the droop c...

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Problems solved by technology

But its shortcomings are also very obvious. Firstly, in order to adapt to the operating conditions of different capacity converter stations and different load levels, an accurate droop ratio plays a very important role in the stable operation of the system. If the selection is inaccurate, it will Seriously affect the stability control of the bus voltage; secondly, under the traditional droop control mode, because the droop control is more sensitive to the line impedance than the master-slave control mode, when the transmission line impedance is taken into account, the bus voltage in the DC power distribution system and The smaller the deviation value of the set value, the smaller the droop coefficient, and the smaller the droop coefficient will affect the system response speed and power distribution accuracy to a certain extent; in addition, there will be steady-state errors in the droop control operation results

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