Voltage collapse bifurcation of a power system transient stability model

Thesis/Dissertation · Mon Jan 01 04:00:00 EST 1990

OSTI ID:6148091

Hu, Ipung

A complete power system model, which is composed of an algebraic load flow model and dynamic generator/exciter model, is developed. This complete power system model is formulated to point out the similarities and differences between the load flow models and the complete power system model that includes electrical generator/exciter and generator mechanical dynamics. Comparison of the load flow and the complete power system model simulation results indicate a converged load flow simulation may not imply voltage stability and will not accurately assess the proximity to voltage instability in the complete power system model. A modified load flow model and simulation method is proposed that includes the effects of line drop compensation, excitation system control, machine saturation, and field current limits. Voltage instabilities are classified into two categories. Load flow voltage instability is caused by supply and demand problem. Dynamic voltage instability is caused by the instability of the flux decay and exciter dynamics. Four voltage bifurcation tests, algebraic, algebraic/dynamic, dynamic/algebraic, and flux decay bifurcation tests are developed in this thesis. The algebraic bifurcation test can identify the supply and demand problem in the distribution system. Algebraic/dynamic and dynamic/algebraic bifurcation tests can detect the instability of the generator dynamics. These tests are applied to analyze a two bus system and a twelve bus system. The results indicate the dynamic generator/exciter portion of the complete model becomes voltage unstable before the algebraic load flow portion of the complete model violates the widely used load flow based tests for voltage instability. Thus, new limits for stable operation must be established based on the instability of the dynamic portion of the complete power system model.

• Research Organization: Michigan State Univ., East Lansing, MI (United States)
• OSTI ID: 6148091
• Country of Publication: United States
• Language: English

Related Subjects

24 POWER TRANSMISSION AND DISTRIBUTION
240100* -- Power Systems-- (1990-)
CURRENT LIMITERS
CURRENTS
ELECTRIC CURRENTS
ELECTRIC GENERATORS
ELECTRIC POTENTIAL
ELECTRIC POWER
ELECTRICAL EQUIPMENT
ELECTRICAL TRANSIENTS
EQUIPMENT
EXCITATION SYSTEMS
LOAD ANALYSIS
MATHEMATICAL MODELS
POWER
POWER DISTRIBUTION SYSTEMS
POWER SYSTEMS
STABILITY
SUPPLY AND DEMAND
TRANSIENTS
VOLTAGE DROP