Control of PMSG-Based Wind Turbines for System Inertial Response and Power Oscillation Damping

Abstract

This paper investigates an improved active power control method for variable speed wind turbines to enhance the inertial response and damping capability during transient events. The optimized power point tracking controller which shifts the turbine operating point from the maximum power point tracking curve to the virtual inertia control curves according to the frequency deviation is proposed to release the "hidden" kinetic energy and provide dynamic frequency support to the grid. The effects of the virtual inertia control on power oscillation damping capability are theoretically evaluated. Compared to the conventional derivative regulator based inertia control, the proposed control scheme can not only provide fast inertial response, but also increase the system damping capability during transient events. Thus, inertial response and power oscillation damping function can be obtained in a single controller by the proposed optimized power point tracking control. A prototype three-machine system containing two synchronous generators and a PMSG based wind turbine with 31 percent of wind penetration is tested to validate the proposed control strategy on providing rapid inertial response and enhanced system damping.

State-of-the-art review on frequency response of wind power plants in power systems

“…One method is to adjust the active power output based on the system frequency deviation. This type of regulation is implemented by means of shifting the operating point upward from the MPPT curve toward the VIC power tracking curve to compensate for power imbalance, and then the rotor speed is controlled to smoothly return to the initial MPP according to (8) [57]. The upper and lower limits of the VIC power curve are defined by applying K VIC_max and K VIC_min respectively to ensure that the VSWT can operate in a steady state under various wind speed conditions.…”

Coordinated Control Schemes of Super-Capacitor and Kinetic Energy of DFIG for System Frequency Support

“…One is the derivative (D) controller, which is proportional to the differential of the system frequency deviation, and the other is the proportional (P) controller, which is proportional to the deviation of the system frequency. In this paper, P controller is used as an inertia response controller for DFIG-based WT since the instability may be caused by D controller because of the noises produced in the frequency measurement [19].…”

“…The second widely used solution is the rotational kinetic energy (KE) of WT rotor mass, which can well stabilize the grid frequency through the proper control design of the so-called emulated inertia control [14][15][16][17][18][19][20][21][22]. In general, when detecting the grid frequency excursion, the set-point of WT generation reference will be accordingly changed.…”

“…Sequentially, partially rotational energy of the WT rotor will be released via rotor speed deceleration when there is a generation shortage of the system or more wind energy will be temporarily stored in WT rotor via rotor speed acceleration when there is a load scarcity of the system. Broadly, the so-called emulated inertia control has three main methodologies including droop control which is based on the system frequency deviation [14][15][16][17], derivation control [18][19][20] which is activated when detecting the change of the system frequency derivation and deloading control [21,22] by defined frequency power curve by shifting the WT operation status from MPPT. The main advantage of the derivation control is that it can emulate the inertia response of traditional SG very well, but it will easily lead to the grid instability with the noise in the grid frequency measurement.…”

Optimum Pole Arc Offset in Permanent Magnet Synchronous Generators for Obtaining Least Voltage Harmonics

“…Among the renewable energy sources, wind energy takes a vital role in decreasing foreign dependence on energy, improving energy reliability, and solving some of the environmental problems. As such, the use of this component of renewable energy is rapidly increasing as the years pass by [4][5][6][7][8][9]. Di erent types of electrical generators used with wind turbines have some advantages and disadvantages over one another.…”