Q. WANG ET AL.

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Figure 6. Comparison of voltage curves of Nanjiang 110 kV

bus for different load models.

Nanjiang bus #2 voltage curves simulated by both ex-

isting load model, SLM, and measured voltage curve are

shown in Figure 6.

From Figure 6, in existing model simulation results,

the bus voltage recover very fast to original level with even

no delay, while the measured voltage recovers slower.

SLM simulation results are close to measured ones with

small variance. Thus it is clear that SLM model has

higher accuracy in voltage simulation.

6. Conclusions

Detailed procedures for the modeling of synthesis load of

actual power network have been proposed in this paper,

then the classification indices based on 1oad characteris-

tics and the principle of load classification have been

expounded. The load characteristics of 2199 220 kV and

330kV substations in Chinese five regional power grids

have been surveyed. Based on the results of general in-

vestigation, the load characteristics have been classified

according to the proposed principle, then based on the

detailed investigation and statistics of load composition

at 220 kV and 330 kV substations, the distribution of

different types of load in domestic power grids has been

analyzed and 120 typical substations have been selected.

Detailed load characteristic investigation of these se-

lected different kinds of typical substations has been car-

ried out. The statistical synthesis method has been used

to model typical substations with SLM model parameters.

The SLM model parameters of same load types in dif-

ferent regional power grids have been synthesized, and

the dynamic model, static model and distribution power

network equivalent reactance have been compared and

combined, then unified SLM model parameters in whole

power grid have been introduced. Finally, the load model

arameters have been evaluated and verified via post-

disturbance simulation method. The effectiveness of

SLM has been validated by the fitting of some distur-

bance incidents.

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