TW200916994A - Droop control device and method capable of predicting the current-sharing degree - Google Patents

Abstract

This invention relates to a droop control device and method capable of predicting the current-sharing degree, applied in redundant or distributed power supply systems and capable of achieving a better sharing effect of load current. The device includes a trans-conductance amplifier, a slope adjustment circuit, a voltage incrementing circuit. In this invention, a trans-conductance parameter is used to improve the slope of output voltage with respect to the output current, and the trans-conductance parameter is used to enable each of the power supply module of distributed power supply systems to have a better and similarslope. The invention dynamically raises the output voltage so as to increase the output current in stepped manner until reaching the range that the system can sustain.

Description

200916994 IX. Description of the Invention: [Technical Field] The invention relates to a slope control device and a method thereof, and relates to a device and a method thereof for predicting the degree of homogenization applied to a distributed power supply system. [Prior Art], the communication system or the computer server is increasingly using distributed power systems (Distributed p〇wer Systems). The decentralized power system is connected with multiple sets of smaller power modules to provide ff and port load terminals. * $ 'Because it has the following advantages compared with the general central power system: Power supply design: When using the central power supply system, '/, when the power specifications required by the customer are changed, it takes time to redesign the power system. In contrast, because of the modular design, the number of power modules connected in parallel can be determined according to the power. In addition, when a parallel module is short-circuited or faulty, the user can also repair the faulty module instead of turning off the power supply system. 2. It can reduce the current stress of power components in a single module: another advantage of the knife-mounted power system is that it can evenly distribute the negative required output current to each parallel module, so a single module can be used with lower ratings. The components are implemented to improve the overall efficiency and volume of the system. 3. Effective thermal management can be achieved: in general, the surface of the electronic component rises. At C, its service life is reduced by approximately one by one. Effective thermal management avoids problems such as premature failure of electronic components or reduced life due to excessive local temperature or when the temperature distribution is too different. Decentralized power systems have a more even distribution of heat sources because they distribute the current of the module evenly. In addition, users can use a larger area of PCB board to dissipate heat. 4. Easy to implement redundant architecture circuit design: Decentralized power system It is easy to achieve N+1 level redundant architecture design. The N+1-level redundant architecture uses N+1 groups of power modules in parallel. In normal operating conditions, the system is powered by N modules. When one of the modules fails, the module will The power is removed and the system maintains the power of the N modules. Therefore, the benefit of redundant architecture is that it can improve the stability of the system. So far, distributed power systems have two methods for distributing load currents, namely, the Droop Methods and the Active Current-Sharing Method. The biggest difference between the active current sharing method and the slope control method is that the parallel module of the active current sharing method requires additional pins (pinouts) for the current sharing control circuit of the parallel module (Current Sharing Control). , CS control) share the information of the output current between each other, and then adjust its own signal, so that the load current can be evenly distributed to each group of parallel power modules. These interconnected pins are commonly referred to as Current-Sharing buses (CS_Bus). The current sharing busbar provides a common reference level for the parallel power supply module, so that the module can be adjusted according to the difference between its output current and the reference level. The slope control law does not use the above-mentioned current sharing bus, but uses a reference voltage as the basis for adjusting the output power. Therefore, the slope control method is superior to the active current sharing method. For example, the circuit design is simple and easy to expand. 2. There is no need for additional connections between modules. The ability to be strong and reliable is as follows: 2. Better current sharing capability. Among the power modules of the law, the seller sells the belt: the decline of the slope control 1 is widely used. It is called the principle ^ regulation t彳 each voltage will follow the effect of the average distribution of the load current, if, change the output impedance of 15, the amount of arrival, is the total demand required by the green ^ mu j load current, please refer to Figure 1. , its power is thousands of power?, the current wave two intentions = the output voltage of the first source module to the output power two 疋 ' and each input _ initial job set value _ is = r corresponding value to the output current of the load „ Output power: It can be observed from Fig. 1 'When the error of the initial voltage value of the individual module is small, the effect of current distribution is better. On the other hand, when the initial error value is fixed, if the output voltage is fixed, The slope of the output current also helps to reduce the difference in output current of individual modules. However, the traditional slope control method, the slope of which is limited by the allowable operating voltage range of the system, cannot be improved. In order to be able to solve the problems of 200916994 = [The inventor based on years of research and development and many practical experience, proposed a slope control method for predicting the degree of current sharing, in order to verify the above-mentioned lack of shape #财式Wei and its Ming content] ^ Bell here, the purpose of the present invention is to provide a 2 & degree of slope control and its method, the use of the slope control method of the power system's current sharing capacity is not good. ', 钭 rate = =明的的' proposes a predictable level of current sharing; the slope control device comprises a transconductance amplifying circuit u, a path and a voltage increasing circuit, wherein the second of the power module generates a detection through a sampling resistor Voltage, transconductance amplification, two voltages are converted into a detection current, and the power of the detection current is output. The mussel, the slope adjustment circuit is further based on the detection current, the slope of the output voltage, the voltage increment circuit, The current information and the modified slope, the gradual increase of the drop in the output is still maintained in the system acceptable change 3 power generation 4 増 production, in addition, the present invention further proposes a square r can be used to reduce multiple power modes The group is supplied; the value of the machine is different. First, the method of the present invention first extracts the rm voltage and an output current from the ^, and calculates - the original ί ^ then 'reuses the sampling resistor from the output current Take = Next, use the - return and detect the electric current rate. Finally, 'step up the output according to the modified slope' 200916994 The output voltage remains within the acceptable variation of the system. The slope control device and method thereof for predicting the degree of current sharing according to the present invention can maintain the output voltage within the system tolerable range and increase the slope of the output voltage to the output current, thereby reducing the output current between the plurality of power modules. The value of the difference, which in turn increases the current sharing capability of the power system. In order to give the reviewer a better understanding and understanding of the technical features and the efficacies of the present invention, the preferred embodiment and the detailed description are provided. [Embodiment] Hereinafter, a slope control method and a device for predicting the degree of current sharing according to a preferred embodiment of the present invention will be described with reference to the related drawings. For ease of understanding, the same components in the following embodiments are used. The same symbol is used to indicate. Please refer to FIG. 2, which is a block diagram showing an embodiment of a slope control device for predictable average process of the present invention. The power module 100 includes a power supply circuit 110 and a feedback control circuit 120. Each set of power modules 100 is connected to the load 300 through an output resistor Rs. The detection module 200 includes a transduction amplifying circuit 210, a slope adjusting circuit 220 and a voltage increasing circuit 230. The power supply module 110 provides an output voltage and an output current to the load 300 according to the signal of the feedback control circuit 120. The transduction amplifier circuit 210 of the detection module 200 also detects the output current. The transconductance amplification circuit 210 samples the output current and feeds it into the slope adjustment circuit 220 and the voltage increment circuit 230, respectively. The function of the slope adjustment circuit 220 is to amplify the slope of the output voltage of the power module 100 to the output current 9 200916994 to produce a modified slope. The voltage-increasing circuit 23〇 step-pulled the output voltage' to cause the output voltage to decrease with the input current to be maintained within the acceptable variation of the system. Please refer to FIG. 3, which is a block diagram showing another embodiment of the slope control device for predictable average flow of the present invention. As described above, the transduction amplifying circuit 210 includes a sample and hold circuit 24, such as a current mirror or an inductor current average generating means. The sample-and-hold circuit 240 copies the detected currents outputted by the transduction amplifying circuit 21A into two groups, and feeds them into the slope adjusting circuit 22 and the voltage increasing circuit 230, respectively. The slope adjusting circuit 22 can use the voltage feedback adjustment circuit 221 (4) to measure the current to be fed into the feedback control circuit 12A at various magnifications, or adjust the feedback resistor 12 of the feedback control circuit 120 to improve the power module. The slope of the output voltage for the output current. As the slope increases, the maximum variation of the turn-off voltage of the power module 100 as the output current increases will increase, causing the output voltage to exceed the system's electrical specification limits. Therefore, the step boost circuit is triggered to increase the output when the output voltage reaches the minimum operating voltage, and the falling amount of the slope control strip voltage of the present invention increases with the input current is still acceptable in the system. Within the change value. Next, please refer to Fig. 4, which is a diagram showing an embodiment of a slope control device for predicting the degree of current sharing of the present invention. Its power supply circuit 11 and feedback control circuit = are known to those of ordinary skill in the art and are described herein. In this embodiment, the power supply circuit 110 is a set of DC 200916994 to DC voltage mode switching converter. When applied to a distributed power supply system, the output of each group of power modules is increased. The last power transistor is used to prevent the failure of individual power modules from malfunction or short circuit. As shown in Fig. 4, the individual power modules 1 加上 plus a power transistor, the equivalent resistance Rs of which can be used as the output resistance RS. The power module 1 is connected to the common output terminal Vg via an output resistor ^ to provide a current demand at the load terminal. In the present embodiment, the transduction amplifying circuit 21A includes a transconductance detector 212 and a current mirror element 211. The transconductance amplifier 212' is used to detect that the output current 1〇 flows through the output resistor RS, and the measurement voltage Vc' is reduced (four) times and then converted into detection, and then transmitted to the current mirror 21丨. The resistor 21 is fed back to form a voltage difference ΔΥίΙ. As mentioned above, when the power module 1〇〇 enters steady state operation, the circuit 120 will let the input voltage of the negative terminal of the error amplifier input the reference voltage value (assuming amplification ^ ideal amplification =). When the current Ιο is equal to 〇Α (ie, no load), the common output voltage V will be equal to the maximum value of the unloaded output voltage of the individual module, assuming that the unloaded output voltage v〇1 of the power module 100 is the maximum value. 'The output voltage V 〇 = V 〇 i. When the output current 1 〇 gradually increases, the detection voltage Ve generated by the flow over the sampling resistor Rs will gradually increase, so the detection current output by the transconductance amplifier Ις It will also gradually increase. Because of the high gain phenomenon of the error amplifier in the feedback control circuit 120, the negative input value is still the reference power of the new terminal, so the price measurement current Ic# outputted by the transconductance amplification ϋ 212 flows to R1 200916994 to generate a voltage difference Δν (1. According to the equivalent circuit model, we can calculate the output voltage

The relationship between Vo and output current 1〇 is as follows:

Vo+Io · Rs · (1+ gm · Rl)=Vref ...... (1) Let an amplification parameter Ka=Rs(l+ gm· Rl)=Rs(l+Ca), then equation (1) Can be simplified to the following formula (2):

Vo=Vref-IoKa=Vref-IoRs(l+gm · R1) (2) In contrast to the conventional slope control method, the output voltage Vo and the output current Ιο relationship are:

Vo+Io · Rs=Vref ...... (3) The derivation of the above formula only needs to remove the detection module 200 of the embodiment from the fifth figure, and can be easily deduced by the equivalent circuit model. This will not be repeated. Comparing equations (2) and (3), we can easily know that the module using the improved slope control method of the present invention can increase the output voltage Vo for the improved slope of the output current 1 Mo Mo' (Ι+Ca). Therefore, the maximum output current difference between the power module 100 can be improved by (1+Ca) times, and the derivation is briefly described as follows: In the conventional slope control method, the difference value of the output current of the two power modules 100 is calculated as follows: :

Vol=Vref-Iol · Rs -Vo2=Vref-Io2 · Rs Δ Vo= Δ Ιο · Rs The difference value of the output current 1〇 of the two power supply modules 100 using the improved slope control method of the present invention is calculated as follows:

Vol=Vref-Iol · Rs(l+gm · Rl) —Vo2=Vref-Io2 · RsH+gm » Rl) 12 200916994 △ ν〇=ΔΙο · Rs · (l+gm · Rl) Therefore, the above formula can be sorted out As shown in the following formula (4): △ Io(max)= △ Vo(max)/Ka (4) where Δ Vo(max) is the output of the individual power module 100 when it is unloaded to loaded The maximum variation of the voltage. Please refer to FIG. 5, which is a schematic diagram showing the waveforms of the output voltage Vo and the output current 1〇 in the embodiment shown in FIG. 5. The above operation principle can be confirmed by the first interval (Region 1) in FIG. 5. At this time, the maximum variation value Δ Vo(drp) of the output voltage Vo of the power module 100 of the present embodiment in the rated current varies with the slope. Increase and increase (Ι+Ca) times. That is, when the output current 1〇 is 1/(1+Ca) times the rated current Io(rate) of the load 300, the output voltage Vo reaches the minimum acceptable value of the system voltage Vo(min), and this The output current 1〇 is much lower than the rated current Io(rate), so it is not sufficient for the supply load 300 to be used. Therefore, as shown in FIG. 4, the voltage increasing circuit 230 of the present embodiment includes a step boosting circuit 231 and a determining circuit 232. The step boost circuit 231 can be constructed by a set of programmable current mirror array circuits. The output current of the current mirror array circuit is obtained after the judgment circuit 232 is triggered, and the switch of the turn-on array circuit is obtained by summing the current. When the output voltage Vo reaches the output voltage minimum value Vo(min), the on current of the current mirror array circuit increases, thereby increasing the output voltage Vo. Therefore, the waveforms of the output voltage Vo and the output current Ιο of the present embodiment enter the second interval (Region 2), the third interval (Regine 3), etc. as shown in FIG. 5 to ensure the present. The output voltage of the embodiment still falls within the electrical specifications that the power module 100 can withstand. 13 200916994 From another point of view, the output voltage Vo of the power module 100 of the present embodiment increases the output current by 1〇 with the improved slope Mo′, and thus the waveform transition shown in FIG. 5, that is, Io(rate When 1/Ka, 2/Ka, ..., (Ka-1)/Ka is multiplied, the step boost circuit 231 is adjusted upward. According to the above theory, we can rewrite equation (2) into equation (5) as follows:

N

Vo=Vref+ Σ Δ Vo(drp)-Io · Ka where Ca=N ... (5)

Ca = l Therefore, Figure 5 has a total of (1 + Ca) intervals. Among them, Vo(nom) in Fig. 5 is the output voltage value when the power module 100 is in operation, and Vo(max) and Vo(min) in Fig. 5 are the maximum and minimum operating voltage values in the electrical specification, and the fifth The Io(rate) of the figure is the full load current (or rated current) of the power module 100, and Δ Vo(drp) is the change of the output voltage Vo when the output current is 1 无 from no load to full load. In summary, the slope control device for predicting the degree of current sharing of the present invention can effectively solve the problem of poor current sharing capability of the power supply system in the prior art. Please refer to FIG. 6 , which is a flow chart showing the steps of the slope control method for predictable average process of the present invention. The steps are as follows: As shown in step S10, an output voltage Vo and an output current 1 取得 are obtained, and the original slope Mo = Δ Vo / Δ 1 计算 is calculated by using the maximum tolerance value of the output voltage Vo and the output current 1 〇. As shown in step S20, an output resistor Rs is provided, and a detection voltage Vc is generated according to the output current 1〇 and the output resistor Rs. As shown in step S30, a transduction parameter Gm is provided, and a detection current Ic=Vc · Gm is generated by the detection voltage Vc and the transduction parameter Gm. As shown in step S40, a feedback resistor R1 is provided, and the voltage drop amount is increased by using the feedback resistor R1 and the detection current Ic, thereby generating an improved slope Mo'=Rs(l+Rl·Gm) greater than the original slope Mo. Mo. As shown in step S50, an output voltage minimum value Vo(min) is provided as a basis for judging whether the output voltage Vo is too low. As shown in step S60: when the output voltage Vo is lower than the output voltage minimum value Vo(min), the output voltage Vo is stepped up so that the output voltage can be maintained within an acceptable electrical specification of the system. In addition, in order to make the plurality of parallel power supply modules have the same slope, if the sampling resistance Rs of the individual power supply modules is different, the slope control method of the predictable current sharing degree of the present invention can be used in one embodiment. The parameter and the feedback resistor compensate for the improved slope Mo' described above. Furthermore, the slope control method of the predictable current sharing degree of the present invention can provide an improved slope greater than the original slope by a factor of Ka, thereby reducing the difference between the output currents supplied by different power modules. Ka times. Therefore, with the power supply system of the predictive current equalization degree slope control method of the present invention, the waveforms of the output voltage and the output current will produce Ka distribution intervals. Please refer to FIG. 7, which is a schematic diagram showing waveforms of output voltage and output current according to an embodiment of the present invention. It can be seen from FIG. 7 that using the power module of the embodiment, since the slope of the output voltage and current of the power module is modified to be steep, the output voltage II and the output voltage of the two power modules are The difference between the value of the 200916994 and the output voltage II and the output voltage 12 of the conventional power supply module shown in Fig. 1 will be significantly reduced. It can be seen that the slope control device and the method thereof for predicting the degree of current sharing can effectively improve the current sharing capability of the power system. The above is intended to be illustrative only and not limiting. Any equivalent modifications or alterations to the spirit and scope of the invention are intended to be included in the scope of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing waveforms of output voltage and output current of a conventional technique; FIG. 2 is a block diagram of an embodiment of a slope control apparatus for predictable current sharing degree of the present invention; A block diagram of another embodiment of a slope control device for predictable current sharing degree of the present invention; FIG. 4 is a circuit configuration diagram of an embodiment of a slope control device for predictable current sharing degree of the present invention; The figure is a schematic diagram of the output voltage versus the output current waveform of an embodiment of the slope control device for predicting the degree of current sharing of the present invention; FIG. 6 is a flow chart of the slope control method for predicting the degree of current sharing according to an embodiment of the present invention. FIG. 7 and FIG. 7 are schematic diagrams showing waveforms of output voltage and output current according to an embodiment of the present invention. 16 200916994 [Description of main component symbols] 100: power supply module; 110: power supply circuit; 120: feedback control circuit; 121: feedback resistor; 200: detection module; 210: transduction amplifier circuit; Mirror element, 212: transconductance amplifier; 220: slope adjustment circuit; 221: voltage feedback adjustment circuit; 230: voltage increment circuit; 231: step boost circuit; 232: judgment circuit; 240: sample and hold circuit; Load; and S10~S60: steps. 17

Claims (1)

200916994 X. Patent application scope: 1. A slope control device capable of predicting the degree of current sharing, applicable to a power module using a slope control method, the power module having an output voltage corresponding to the original output current of one of the power modules a slope, wherein the power module includes a sampling resistor, the detection module includes: a transduction amplifier circuit, which generates a detection voltage generated by the output current of the power module through the sampling resistor Detecting current and outputting information of the detected current; a slope adjusting circuit for modifying the original slope according to the information of the detected current; and a voltage increasing circuit, when the output voltage is according to the modified slope, As the output current increases and decreases to a value lower than an output voltage, and the output current is lower than a current preset value, the voltage increasing circuit pulls the output voltage according to the information to continuously increase the output current. To approach the current preset value. 2. The slope control device of claim 1, wherein the transduction amplifier circuit comprises a transconductance amplifier. 3. The slope control device of claim 1, wherein the transduction amplifying circuit further comprises a sample and hold circuit for sampling the detected current to generate the poor signal. 4. The slope control device of claim 3, wherein the sample and hold circuit is a current mirror. 5. The slope control device of claim 1, wherein the slope adjustment circuit comprises a feedback resistor. 6. The slope control device of claim 1, wherein the voltage increasing circuit is a step boost circuit. 7. For example, the slope control device of claim 1 of the patent scope, wherein the modified oblique 18 200916994 value 'and the modified slope symbol 8; ϊ:= ΐ ΐ slope control method can reduce the complex number using the oblique thinking I method The output value of the gates of the plurality of round currents output by the electric/original mode rainbow, the slope control method comprises: the difference between each of the power modules is obtained by an output voltage and an input, and the following: The dielectric output voltage and the output current are obtained - the original slope::, the supply-sampling resistor' and the output current is passed through the generated voltage as a detection voltage; 7 taste parameters, and the voltage and the derivative parameters are generated a detecting current; and f two-seat low/supply resistance 't using the feedback resistor and the detecting current to reduce the output current, and modifying the original slope; and when the power is applied to the voltage t According to ^ has modified the slope 'following the output current two low value' and the round current is lower than the preset power hunger value, the output voltage is stepped up and increased to approach the preset current value. "Output power catching continues 9. If the slope control method of the patent application scope item 8 is applied, the transmission parameters and the power supply module of the Laisaki Electric Co., Ltd. have the same modified slope. Τ_便讥 such as the slope control method of the eighth application of the patent scope, the second derivative parameter is such that the modified slope is greater than one of the original slopes' . ......11. As in the slope control method of claim 8, the waveform of the voltage in the basin and the waveform of the output current have a plurality of intervals, and the number of intervals is proportional to the multiple. δΛ complex number 200916994 12. The slope control method according to claim 8, wherein the power supply modules are applied to a redundant or decentralized power supply system, and the power supply system provides a preset load current to the The load, the preset current value is the average current value of the preset load current divided by the number of the power modules. 13. The slope control method of claim 8, wherein the modified slope value is greater than the original slope value, and the modified slope sign is the same as the original slope. 20