Case study on the integration of a non-utility induction generator to the Hydro-Quebec distribution network

Abstract

This paper investigates the influence of different factors (such as load and capacitive compensation levels, load and turbine dynamic behaviors, machine parameters) on induction generator self-excitation phenomena and related overvoltages, resulting from a fault andor an unwanted network disconnection. Simulations are performed on a 25 kV distribution network related to an actual project of integration of a nonutility induction generator to the Hydro-Que%ec system. The paper presents the analysis of the results, as well as the derived guidelines for the determination of new relay settings and integration criteria for the Hydro-Qu6bec distribution network.Kevwords. -Induction generator, self-excitation, system disconnection, dynamic simulation, distribution network, relay settings. APPENDIXThe induction generator parameters are as follows : R1 = 0.0134 P.U. R2 = 0.0082 P.U. Xi = 0.1278 P.U. X, = 0.1236 P.u. Vbase = 4 kV X, = 3.904 P.U. for g = -0.0088 R2 = 0.0302 P.U. X, = 0.0613 p.u. for g = -1.0 The resistances and reactances are expressed in per unit on the machine voltage and MVA ratings. Sbase = 3.219 MVA H = 0.372 S.

Performance of the OVP/UVP and OFP/UFP Method With Voltage and Frequency Dependent Loads

“…It was concluded that the choice of the DG interface control has an effect on the NDZ and on the choice of the suitable islanding detection method. In [8], the effect of voltage-dependent loads on the operation of an induction generator during an islanding condition was examined. The voltage and frequency deviation were found to be dependent on the load model [8].…”

“…In [8], the effect of voltage-dependent loads on the operation of an induction generator during an islanding condition was examined. The voltage and frequency deviation were found to be dependent on the load model [8].…”

“…Since the DG is designed to supply zero reactive power, the reactive power mismatch equation could be written as (6) where represents the operating frequency in radians per second. Substituting (4) and (5) in (6) and simplifying 7A mismatch in reactive power will result in a frequency deviation and (7) could be written in terms of (Hz) as follows: (8) where and represent the change in frequency from nominal frequency in hertz. The relation between the reactive power mismatch and frequency deviation is expressed in (9) (9) Equation (9) highlights the fact that the load's voltage and frequency dependence has no effect on the amount of frequency deviation.…”

Comparative Analysis Between Synchronous and Induction Machines for Distributed Generation Applications

“…Although most induction generators in operation are employed in wind power plants [3], [6], such machines have also been used in medium-size hydro and thermal plants [3], [7]- [9]. Therefore, in order to keep the results as generic as possible, the mechanical torque was considered constant, i.e., the regulator and prime mover dynamics were neglected.…”

Investigation of the islanding detection of induction generators

“…In this context, squirrel-cage rotor induction generators have received augmented attention due to some advantages over synchronous generators such as lower unit cost, smaller size, less maintenance requirement. Although most induction generators in operation are employed in wind power plants [1], [3], these machines have also been used in medium size hydro and thermal plants [1], [4]- [6]. Consequently, it is fundamental to analyze the impacts of the induction generator installation on the distribution network operation as well as to understand the performance of these generators under normal and disturbed operation conditions.…”