1. Field of the Invention
The present invention relates to inverter control technology, and more particularly to an inverter control module that is capable of suppressing harmonics.
2. Description of the Related Art
An inverter generally comprises a control unit, a power module, and a wave filter, as shown in
The control of a conventional inverter, as shown in
Pulse width modulation technology for application to an inverter includes hysteresis comparator current control method, triangle wave current control method, horizontal phase wave carrier pulse width modulation method, predictive current control method, space vector modulation method, etc. Every one of the aforesaid various methods has its advantages and disadvantages. For example, the hardware circuit of the hysteresis comparator current control method is quite simple, however its switching frequency is not constant and difficult to control. Further, it contains a high percentage of harmonic components. The triangle wave current control method has the advantage of ease of frequency control, however, this method has a low response speed and can cause phase shift problems. The predictive current control method has the advantages of constant switching frequency and rapid response speed, however, this method requires precision circuit parameters and complicated computing process. Further, this method is a first-order approximation differential. In general, the aforesaid various pulse-width modulation techniques have their advantages and disadvantages, however, the major common drawbacks of the aforesaid various pulse-width modulation techniques is the current signal contains a big amount of harmonic components, as shown in
Subsequent prior art techniques adapted to overcome the aforesaid problems commonly use a RLC (resistor, inductor and capacitor) combination circuit consisting of multiple passive components to constitute a filter, such as band-pass filter or low-pass filter. However, these techniques still cannot effectively improve harmonic wave problems. In actual application, these techniques can lead to occurrence of series and parallel resonance problems.
The present invention has been accomplished under the circumstances in view. It is main object of the present invention to provide an inverter control module with harmonic suppression capability, which uses an error signal generated by an electronic circuit or process flow of an error detection unit to increase the switching frequency of a power module of an inverter module, thereby effectively suppressing any harmonic signal generated by the inverter module.
To achieve this and other objects of the present invention, an inverter control module of the invention is electrically connected to an inverter module. The inverter control module comprises an error detection unit adapted to receive and process a control signal and a feedback signal from an external source and then to output a corresponding error signal, a signal amplifier module electrically connected to the error detection unit and adapted to receive the error signal from the error detection unit and to amplify the error signal at a predetermined amplification ratio or to raise the frequency of the error signal for output, and a driver module electrically connected to the signal amplifier module and adapted to receive the amplified or frequency-raised error signal from the signal amplifier module and to generate a corresponding driving signal and then to output the driving signal to the power module of the connected inverter module for driving the power module to work.
Other advantages and features of the present invention will be fully understood by reference to the following specification in conjunction with the accompanying drawings, in which like reference signs denote like components of structure.
Referring to
Referring to
Further, except the hardware and software designs with signal amplification capability, the signal amplifier module 12 can also be designed to raise the frequency of the error signal to a predetermined level and to amplify the signal at a predetermined amplification ratio. Therefore,
Therefore, any electronic design such as frequency multiplier or up-converter circuit with frequency-raising function, or any device equipped with a mathematical model, program, process flow and other forms of software components capable of raising the frequency shall be included in the design criteria of the signal amplifier module 12.
Referring to
Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.
Number | Date | Country | Kind |
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102104740 A | Feb 2013 | TW | national |
Number | Name | Date | Kind |
---|---|---|---|
4030015 | Herko et al. | Jun 1977 | A |
4322787 | Kraus | Mar 1982 | A |
4667283 | Seki et al. | May 1987 | A |
4719558 | Hanada | Jan 1988 | A |
5355025 | Moran et al. | Oct 1994 | A |
20070096680 | Schroeder et al. | May 2007 | A1 |
Entry |
---|
Johnston, R.H.; Boothroyd, A.R., “High-frequency transistor frequency multipliers and power amplifiers,” Solid-State Circuits, IEEE Journal of , vol. 7, No. 1, pp. 81,89, Feb. 1972. |
Number | Date | Country | |
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20140218984 A1 | Aug 2014 | US |