The present invention relates to a method for controlling power supply and particularly to a power supply control method that controls an inverter through a cycle control signal of varying modulation modes to provide power supply control in a high reliability and a wide dynamic range.
The conventional control method for power supply or energy regulation, such as dimming control, generally adopts time cycle with an ON-OFF interval to regulate ON-OFF cycle (T1, T2) ratio to get different output energy (referring to
The conventional EDR is
Based on equation-1, the conventional EDR is infinite. (Its meaning is similar to bending a steel wire to 90 degrees and straightening again. If the process is repeated many times, the steel wire will be ruptured. If the steel wire is bent only 10 degrees, it can be bent many more times than by bending 90 degrees before ruptured). The conventional energy control method set forth above has a great impact to the life span of the load. When the EDR is excessively large, the load has to function in two extreme conditions, and aging of the load is accelerated.
Another conventional method to control power supply (referring to
(Referring to
Total energy
(Maximum energy output)
EDR
(Half energy output), (Referring to
EDR:
(Referring to
The method depicted above also has problems. When total regulation energy changes, the maximum wave amplitude of excitation energy also decreases. It could happen that the load cannot be actuated to function at one half of the amplitude energy (½EA) (such as the lamp cannot be ignited because of the voltage is too low, or some electromechanical elements cannot be activated because of the peak actuation energy is not adequate).
The primary object of the present invention is to solve the aforesaid disadvantages. The invention provides a standby mode function during OFF-Time to improve the modulation range of the original system and maintain the entire operation of an inverter so that the load may be actuated effectively, thereby to control the inverter and the load effectively to achieve a higher reliability and efficiency for the product, and also prevent the product from aging too quickly.
To achieve the foregoing object, the method for controlling power supply through multiple modulation modes according to the invention provides a cycle control signal of varying modulation modes to control an inverter of selected characteristics and keep the inverter and a load on the rear end to operate within a reliable characteristic range, and prevent the load from aging too quickly. The method of the invention inputs a total energy control regulation signal to an input end of an energy/time ratio synthesizing control unit to get a cycle control signal on an output end thereof that contains an ON-Time and an OFF-Time, and adds a regulation energy of varying amplitudes or frequencies in the OFF-Time during the burst period of two ON-OFF cycles. By regulating the duty cycle, or through frequency modulation and amplitude modulation, the power supply may be controlled with a higher reliability and in a wider dynamic range.
The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
Please refer to
To implement the method of the invention, the apparatus being used include: an ON-Time energy (EA) regulation unit 1, an OFF-Time energy (EB) regulation unit 2, an energy/time ratio sequence control unit 3, and an energy/time ratio synthesizing control unit 4.
The ON-Time energy (EA) regulation unit 1 has two input ends 11 and 12. The input end 11 receives a reference signal of a set duty frequency point. Another input end 12 receives a feedback error signal to adjust the duty width. The ON-Time energy (EA) regulation unit 1 has an output end 13 to output an energy regulation signal of the ON-Time to determine the energy intensity (EA) of the ON-Time and send to the energy/time ratio sequence control unit 3.
The OFF-Time energy (EB) regulation unit 2 also has two input ends 21 and 22. The input end 21 receives the same reference signal of the ON-Time energy (EA) regulation unit 1. Another input end 22 receives an error signal potential to change the time relationship of reference sequence signals. It has an output end 23 to generate another energy regulation signal of the OFF-Time and output to the energy/time ratio sequence control unit 3 to determine the energy intensity (EB) of the OFF-Time. The energy intensity (EB) is smaller than the energy intensity (EA) of the ON-Time.
The energy/time ratio synthesizing control unit 4 has an input end 41 to receive a total energy control signal which includes an energy regulation ratio of a selected range such as alter from 10% to 100%. It has output ends 42 and 43 to get an ON-Time and OFF-Time cycle control signal (TA/TB) that is distributed respectively to the ON-Time energy (EA) regulation unit 1 and the OFF-Time energy (EB) regulation unit 2, and output to the energy/time ratio sequence control unit 3. Finally an output end 31 of the energy/time ratio sequence control unit 3 outputs a basic phase control signal (different energy total or control signals generated according to the modulation method of the invention), and another output end 32 outputs a complementary phase control signal which complements the basic phase control signal, thereby to control an external soft resonant component 6 to perform desired energy waveform transformation. Then send the energy waveform (proximate to a sinusoid wave) to a power transfer element 5. The transformed signal (voltage boosting or lowering signal) is sent to a load 7 (such as lamp, rectification circuit, or the like). Please refer to
To change the output energy amplitude, the duty width is changed without changing the frequency. As the frequency remains the same, the power transfer element 5 that equips with bandpass characteristics can operate on the maximum efficiency point. Since the width is changed, after having output through the soft switching component 6, a voltage wave of smaller amplitude may be obtained. Hence the voltage on the load 7 is changed and a regulation controlling function is accomplished.
Moreover, during regulating the energy intensity, the ON-Time energy intensity (EA) still maintains the maximum energy amplitude and is controlled by the ON-Time energy regulation unit 1. But the OFF-Time energy amplitude (EB) is controlled by the OFF-Time energy regulation unit 2 to add an average energy of the ON-Time (TA) and the OFF-Time (TB) to the regulation input end to regulate the width of another cycle in the OFF-Time (TB). The basic energy amplitude of this width is much smaller than that in the ON-Time (TA). However, on average, an intensity control effect still can be achieved without any intermittent interruption.
On of the embodiments is to adopt constant frequency and regulating duty width, namely altering the duty width (i.e. the length of ON-Time (TA) and the OFF-Time (TB)) without changing the frequency (referring to
Refer to
In yet another embodiment, a stop time (TC) of energy intensity 0 (EC=0) is added to the OFF-Time (TB). Then a controllable cycle composition of multiple modulation modes may be realized. And the same result can be achieved (referring to
Refer to
Refer to
By means of the method previously discussed, after adding a modulation energy EB of varying amplitudes in the stop time (TC), a new EDR may be obtained as follow:
(where TTOTAL is the burst period).
As the energy sent to the load end is the same, power supply regulation control may be achieved. The EDR is much smaller than the original infinite. Hence the problem of rapid load aging is improved.
In addition, the invention can maintain the original peak dynamic energy and regulate total energy at the same time. Thus the energy regulation dynamic range may be expanded without damaging the life span of the load (whereas, the control signal in TA/TB may be constant frequency, width modulation or frequency modulation, constant width, or modulation of both).
Refer to
(where TA/TB is the time ratio for energy rationing).
While the preferred embodiments of the invention have been set forth for the purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.