1. Overview of Music Fountain
The music fountain combines the spirituality of water, the beauty of music and the color of light perfectly, giving people a pleasant feeling. Music fountain system has become an important part of urban landscape construction because of the unique effect of sound, light, water and color. With its reliable quality, excellent technical performance and high performance-price ratio, HEDY frequency inverter has not only been applied in domestic music fountains, but also been abroad, bringing more gorgeous colors to many foreign cities
HEDY Inverter used in Iranian Music Fountain
Iranian music fountain
2. Principle of music fountain
The music fountain system is composed of audio control system, fountain control system and light control system. According to the height of the water column, the music can express the joy, anger and sadness of the music, and achieve the effect of synchronizing with the music. The speed of the pump is proportional to the frequency. There are many sources of frequency inverter frequency signal, one of which is the sound source output from the sound system. The signal is amplified, filtered, limited and detected by a conversion circuit, and the envelope detection signal number proportional to the logarithm of the music amplitude is sent to the acquisition card. The signal is generally 4 ≤ 20 Ma. According to the analysis and statistics of a large number of music audio signals, The signal changes in real time, so that the water column and the water column can be realized. Change with the melody of music.
The previous change in the water column of the music fountain is controlled by the valve, and the height of the water column can be changed by controlling the opening of the valve. The water of water produced in this way is relatively hard. At the same time, the running speed of the water pump is constant, and the power consumption is fixed, so that a large energy loss can be generated, and a great use cost is brought to the landscape engineering. The control of the water-in-water type can be avoided by the control of the frequency inverter, and is introduced into the fountain system for controlling the water pump. It is found that the frequency control based on the frequency inverter can be used for stepless speed regulation, so that the water column can be changed according to the rhythm of the music, so that the water is more spiritual and the fountain is more beautiful.
HEDY HD700 series
The frequency inverter has an analog input interface, and the frequency of the frequency inverter can be set by inputting different analog quantities. The input port of the analog quantity is indirectly controlled by the music signal, so that the frequency of the frequency inverter is controlled to be output, and the height of the water column is further controlled. The other method is a digital method, the seven-step frequency inverter supports the Modbus RTU communication, and the upper computer is used for calculating the frequency of each frequency inverter at a certain time according to the music piece and directly transmitting the frequency command to the frequency inverter according to the music piece, and the frequency inverter is output according to the instruction. The frequency inverter controls the topological side type of the water pump, can control one water pump by one frequency inverter, and can also control multiple water pumps at the same time by one frequency inverter The water pump, or a frequency inverter, can control multiple pumps in time, depending on the actual situation, the control mode is very flexible. A large music fountain is often composed of hundreds of water pumps (we use 300 sets of left and right in a fountain project in a certain city in Iran) to form a running spring, and through the control of the frequency inverter, a long and low-wave long-dragon is formed, and a variable-frequency moment array can also be formed. And the water column with different heights is used to form a colorful three-dimensional model. During the control process, the water is required to follow the curve, the follow-up speed of the frequency inverter is high, and the acceleration/ deceleration time requirement is small. In the Iranian music fountain project, the seven-mode frequency inverter HD700 is selected Series, with deceleration time of 0.1 s, fully meet the customer's use requirements.
Application requirements of frequency inverter
（1） fast response, can match the rhythm of music in real time
（2）online switching motor does not trip
（3） fast acceleration and deceleration time, 0.3 s to complete 0~45Hz variable speed
3. Application of HD700 Inverter in Music Fountain
4. Application characteristics of HD700 Inverter
A. Double CPU design, more accurate control, faster response
B. Good acceleration and deceleration performance, can implement the rhythm of music, ensure the perfect fountain effect
C.IGBT design margin is large, overload capacity is strong
D.A variety of protection functions, Better protection of motor and frequency converter itself
E. Support analog input and bus communication.
