Dry-type air-core reactor for HVDC power transmission project has large size and capacity and the harmonic power supply for the noise test is very difficult to find.For finding feasible equivalent test method

in this paper

the equivalent current method and constant proportional current drop method in the test method of dry-type air-core reactor specified in the related standards are verified experimentally.The equivalent current is to decompose the electromagnetic force inside the air-core reactor by applying currents with multiple different frequencies simultaneously so decompose the electromagnetic force component of any frequency

which can be equivalent to the electromagnetic force under action of corresponding single frequency current.During the test

each equivalent single frequency current mentioned above is applied individually to measure the average sound pressure level of one group of reactor

which is then subject to energy superposition and

finally

the average sound level of the reactor after superposition is obtained.It is found through test and comparison that the average sound level of the reactor under the action of applying multiple harmonic combination current simultaneously is approximately equal to the sum of average sound level superposition under respective action of each equivalent single frequency current of the combination current and the deviation is less than 1 d B（A）.The constant proportional current test method is to perform the test through constant porportionally decrease the amplitude of multiple harmonic combination current

then the sound power is calculated of the reactor under original combination current with the constant proportion ssound level calculation formula.The test method can reduce the requirement to the programmable multiple harmonic power capacity and have perfect equivalence with the decrease proportion is above 70%.