The invention relates to a coastal wave energy power generating
system with parametric
resonance. The
system comprises that: a wide and large water port is arranged
underwater at the coast of the lowest
water level; the water port is connected with the bottom part of a fairing which is provided with a
water turbine rotor through an outer
water channel; the upper part of the fairing is connected with the bottom part of a water tank of which the section is rectangular through an inner
water channel; the upper part of the water tank is provided with a compression
air chamber, and the compression
air chamber and the section of the water tank are rectangular; an air valve is arranged between the compression
air chamber and the water tank; the water tank is provided with a
water level sensor internally; the
water level sensor is electrically connected with an air valve controller; and the air valve controller is electrically connected with the air valve. According to the invention, the
resonance amplitude of a parametric
resonance system provided by the invention is doubled of that of the common resonance, and wave energy can be effectively collected; the design of the whole
wave power generating device is easy to master, and is especially suitable for the
natural energy such as
waves of which the frequency and
resonance amplitude change constantly; and under the condition that the outer excitation
resonance amplitude increases by a large margin, the
resonance amplitude of the water level for the water tank only increases with
small amplitude, and the system has the capability of resisting the outer large
waves.