A novel methodology for effective short-circuit calculation in offshore wind power plants considering converter limitations

A New Short-Circuit Current Calculation and Fault Analysis Method Suitable for Doubly Fed Wind Farm Groups

“…Assuming that the stator voltage u s0 before the fault is rated, the active and reactive power depend on the setting of the working conditions before the network failure. The rotor flux ψ r is obtained from Equation (15) and the rotor flux ψ r is brought into Equation (12) to obtain the short circuit current i ' so at the initial moment of grid voltage drop.…”

“…In this case, the output short-circuit current of the DFIG is affected by the converter control characteristics [14]. Therefore, it is necessary to consider the low-voltage crossing control strategy and the control characteristics of the converter when calculating the short-circuit current [15].…”

Grid Equivalent Representation of Power Systems With Penetration of Power Electronics

“…Then, a set of systems of equations, SE, considering the inserted z out , is defined and solved. Potential existence of multiple equilibrium points is ignored in this paper and the solution function, which is defined in [32] for single-phase expression, returns the identified equilibrium points as a vector (u outx , u outy , i outx , i outy ). Each obtained solution is saved into the U-I characteristic array C eq .…”

“…In particular, the equivalent model of power converters, which involves a specific control mode and various potential current-saturation states, is included in the system formulation. Then, the system equilibrium point that satisfies all converters' operation limits can be identified by either going through all possible combinations of converters' current-saturation states [30], [31] or testing only selected combinations iteratively for a more efficient calculation [32], [33]. The previous studies are based on the formulation of the complete studied system.…”