106
Z. Lu and G. Zhu
Fig. 4.1 Demonstration project of 4 terminal VSC-HVDC from Zhangbei to Beijing
1. Prevent large-scale power shift and cascading failures that can propagate across
the AC-DC transmission systems as the result of a fault in the receiving-end of
DC power transmission system.
2. The problem of voltage instability triggered by the restart following commutation
failure in multi-feed DC receiving-end.
3. The issue of frequency fluctuation and instability due to reduced system inertia.
4. With an increasing number of power electronic devices such as for wind power
solutions connected to the grid, broadband oscillations (1-kHz) are produced by
the interactions among power electronics as well as between power electronics
and the AC grid.
The analysis, simulation and control of subsynchronous or high-frequency oscillations sparked by the integration and interfacing of power electronics to the grid
will become crucial matters. The above-mentioned problems have presented new
challenges to existing grid simulation and system analysis. In the future, with more
connection of sophisticated power electronic devices to the grid on a greater scale,
it will be even more difficult to manage the complexity of the grid. Therefore, more
work needs to be done in the research of grid characteristics, the development of
modelling and simulation technology and control measures to ensure the safe and
reliable operation of China’s AC/DC hybrid power system.
Z. Lu and G. Zhu
Fig. 4.1 Demonstration project of 4 terminal VSC-HVDC from Zhangbei to Beijing
1. Prevent large-scale power shift and cascading failures that can propagate across
the AC-DC transmission systems as the result of a fault in the receiving-end of
DC power transmission system.
2. The problem of voltage instability triggered by the restart following commutation
failure in multi-feed DC receiving-end.
3. The issue of frequency fluctuation and instability due to reduced system inertia.
4. With an increasing number of power electronic devices such as for wind power
solutions connected to the grid, broadband oscillations (1-kHz) are produced by
the interactions among power electronics as well as between power electronics
and the AC grid.
The analysis, simulation and control of subsynchronous or high-frequency oscillations sparked by the integration and interfacing of power electronics to the grid
will become crucial matters. The above-mentioned problems have presented new
challenges to existing grid simulation and system analysis. In the future, with more
connection of sophisticated power electronic devices to the grid on a greater scale,
it will be even more difficult to manage the complexity of the grid. Therefore, more
work needs to be done in the research of grid characteristics, the development of
modelling and simulation technology and control measures to ensure the safe and
reliable operation of China’s AC/DC hybrid power system.