Control Strategy for Improving the Voltage Regulation Ability of Low-Carbon Energy Systems with High Proportion of Renewable Energy Integration

Abstract

In low-carbon energy systems, due to the high proportion of renewable energy access, the voltage regulation capacity of the system will decrease. Therefore, in the event of voltage violation, it is easy to cause large-scale renewable energy off-grid and power outages. In order to improve the voltage regulation ability of low-carbon energy system, this paper proposes a two-stage overvoltage suppression strategy for sending-end power grid. Firstly, the principle of overvoltage phenomenon in the sending end power grid of low-carbon energy system with high proportion of renewable energy access is studied, and an overvoltage control strategy composed of two stages of centralized control of rectifier station and flexible resource control of distributed power grid is proposed. Then, the PSO algorithm and consensus algorithm are used to solve the established control model. Finally, a simulation system is established based on actual operating power grid data to verify the proposed control strategy through simulation. The results indicate that the control strategy proposed in this paper can effectively suppress transient overvoltage of AC buses and improve the operational stability of the high proportion of renewable energy sending-end power grid under various operating conditions. In addition, during the daytime overvoltage regulation process, the potential of flexible regulation equipment can be fully utilized. Shortening the duration of voltage exceeding the limit and reducing the peak voltage exceeding the limit can help reduce the renewable energy waste rate of the power grid.

Investigation of the Feasibility of the Dynamic Equivalent Model of Large Photovoltaic Power Plants in a Harmonic Resonance Study

“…Then, the harmonic response of the control loop, the DC capacitor, and the filter are derived, which leads to the harmonic current at the PCC. The relationship between the harmonic voltage and the harmonic current of a grid-connected PV inverter can be then determined as a 2 × 2 harmonic coupling matrix, as shown in Equation (1). Please refer to [28] for detailed steps.…”

“…With the increasing prominence of environmental issues, the development of renewable energy power plants, such as solar power plants, has rapidly progressed; moreover, renewable energy power plants have become an important supporting power source for power systems around the world [1,2]. However, in the grid integration practice of largescale renewable energy power plants, several harmonic resonance accidents have occurred, as shown in Table 1.…”

Variable Reactance Criteria to Mitigate Voltage Deviations in Power Transformers in Light- and Over-Load Conditions

“…Currently, there are also renewable energy generators that impact the grid voltage levels, especially if not properly controlled [7]. Last but not least, the over-voltage level may be due to inadequate grid planning or even voltage regulation and control issues [8,9], as the traditional load voltage regulating transformers are still used [10]. Therefore, there is still room for improvement in this area, and the present paper encompasses this general topic.…”