TWI234698B - Output voltage balance control device for three-phase half-bridge type power factor correction - Google Patents

Abstract

An output voltage balance control device for three-phase half-bridge type power factor correction is disclosed, wherein three inductors are connected to the input ends of the three-phase power respectively, and four diodes are connected in series respectively after the inductors of the two phases, so as to form the two power output ends of three-phase, half-bridge type. Also, the four diodes are connected to four switches respectively, and the loads of the two output ends of power are connected to two output capacitors respectively. A current hysteresis control circuit is employed to control the switching operation of the four switches, so as to achieve the purpose of generating the maximum power factor and minimum input current harmonics of the two output balanced stable voltage at the two output ends of power.

Description

1234698 V. Description of the invention α) [Technical field to which the invention belongs] The present invention relates to a three-phase half-bridge power factor corrector output voltage balancing device, in particular to a three-phase half-bridge power factor corrector with double output capacitor balance ， Using the working principle of high-frequency switching to reduce low-frequency harmonics. : Previous technology] According to the widespread use of various power converters, the problem of power supply harmonics has attracted attention. At present, no matter in China or advanced countries such as Europe, the power factor and harmonic pollution of electrical equipment have requirements and restrictions. Therefore, how to improve the current waveform and the power factor of the converter input has become the industry's Top priority. Traditional three-phase AC / DC converters are bridge-type three-phase rectifiers based on passive element diodes. As shown in the first figure, the advantages of such bridge-type three-phase rectifiers are simple circuits, low cost, and robustness. However, because the working principle of the circuit is an uncontrolled natural commutation method, the input current of the power supply will be a non-linear distortion waveform containing low-frequency harmonics. As shown in the second figure, this non-linear distortion current waveform will As a result of reducing the power factor of the circuit (between about 0.4 to 0.6), the harmonic components contained in it will also generate electromagnetic interference, affecting other communication systems and precision electronic equipment, and even when this distorted waveform is fed back into the power supply The system will cause imbalance of virtual power and affect the power supply quality of the entire power system.

In this circuit, the input voltage v is the input current d, and its power factor PF is the average power P (average power) versus the apparent power S

Page 5 1234698 V. Description of the invention (2)

P ~ S # 1

PF cos apparent power), ^, where the average power P = Vs * i si * eos is, the apparent power s = vs * i s. In the above formula, i 5 is the fundamental frequency component of i 妁, and is defined as the phase shift of i s relative to v 妁. Therefore, according to the formula of the power factor, there are two factors that cause the power factor to decrease. One is that the input current is contains harmonic components, so that the ratio of i sl to i is less than 1, and the other is that the input current i is different from the input voltage v. Phase, resulting in a value less than 1. Therefore, if you want to improve the power factor, you must try to make the input voltage v and the input current i-phase, and the input current i has a sine wave waveform. For this reason, a power factor correction (PFC) is used in the industry to keep the input current in a sinusoidal waveform and in phase with the power supply voltage. The simple power factor corrector is to add passive components such as inductors and capacitors with low-frequency harmonics generated by the energy efficiency suppression circuit at the input end. Although this can improve the power factor, it does increase the volume and weight of the converter, causing users Inconvenient. The traditional three-phase power factor corrector, as shown in the third figure, uses six transfer switches S1 and S6 in parallel to six bridge rectifier diodes D1 and D6, respectively. Each phase current ia, ib, i is to control the input current by turning on and off of two switching switches and the diode, so that it has a sinusoidal waveform with the same phase as the input power voltage to achieve the correction of power factor, but because of the conventional correction The device uses a large number of switching switches and fast diodes, which complicates its control circuit and increases the switching loss of the switch.

Page 6 1234698, Invention Description (3). The post's inventor is to solve the above existing three-phase power factor repair device = with inconvenience and deficiency, is a research and development of a three-phase half-bridge power factor repair center with dual output capacitors 1 '. It mainly uses the working principle of high-frequency switching, which can solve the problem of low-frequency wave k ^ and use fewer circuit components to reduce the volume of the circuit. The double-balanced voltage from iff * can supply one positive, one negative, and two. The design of the DC power supply is a reasonable design and effective invention. [In the invention, the three-phase current rate factor correction terminal of the present invention is connected in series with four negative circuits of the four two output terminals to generate power at the output. The power factor control circuit of the two is compatible.] Ming Department The main positive output that provides half-bridge power is connected to three electric diodes, and the four double-output flat-effecters are controlled separately on the pole body. The next-time corrector input includes the technical factor corrector with two inputs below. The technical characteristics are voltage balance sensors, and it is the best way to form a three-phase, three-phase, four-parallel, and two-input switch. The solution lies in the two-bridge switching of the device, the switching of the capacitor, the switching of high power, and the use of low-frequency harmonic power supply. It is based on the three-phase electric two-power output, and then borrows one to achieve the factor and The problem of the least circuit element wave: Phase half-bridge power phase power input sensors are respectively output, and the two power supply hysteresis control The two power supply low input current technology is characterized by providing the above three-phase A half-bridge output voltage balance control device, wherein the current hysteresis current sensor is connected in series with the three-phase power input terminal, and the two-phase input current is replaced with a voltage signal.

Page 7 1234698 The number corrector circuit further includes a symmetrical element, the balance control number, and the level of the main stream. Another number corrector circuit of the invention further includes a shape and follows the input power voltage; The current hysteresis circuit then commands the current to switch through a hysteresis time to achieve the number control and the lowest input current harmonics. The three-phase half-bridge device is provided. The current hysteresis circuit is used to provide a feedback. Complement the command current value to reduce the output or increase the output voltage to control the output voltage. The three-phase half-bridge device is provided. The current hysteresis is used to resolve the DC offset voltage into two output voltage imbalanced output voltages. The difference is first multiplied by an addition to increase or decrease the power to achieve the dual output electrical balance to provide the above three-phase half-bridge device. The current hysteresis is based on the technical proportional voltage product of the current hysteresis circuit. The output power and the voltage will also follow the work technology, and the voltage balance control will be followed by the circuit, which will make the second and fifth, invention description (4); two step-down transformer phase The command current is used to compare the two-phase input comparators and then control the functions of the two power output terminals. The other power factor corrector output control circuit of the present invention further includes a compensator. The load feedback voltage can respond to the input load and then command the current at that time to achieve a stable power input. Use phenomenon, the proportion often turns into electrical efficiency. This power generates two sine waves due to the control power. Let the input current chase the current and the four switches should be controlled to produce the most two power. The reason is that the balance is controlled by the control power to control the increase. . The problem lies in the balance control control circuit. The error caused by the two inputs is the command current output voltage. The technical feature is the voltage balance control output drive circuit.

1234698

In the control signal, the control terminal of the on-time period and the control signal of the main switch are overlapped when the switch is inserted into the blank, which results in the ground terminal number of the circuit and has the same effect. In order to ensure that the circuit is short-circuited and isolated, in order to prevent the control from amplifying the four switches, the control can stop the input power signal, so that the switch will not switch due to the ground interference of the signal. It is sufficient to trigger. Your reviewers can further understand the technology, means and effects adopted by the present invention to achieve the intended purpose. Please refer to the following detailed description and drawings of the present invention. I believe that the purpose, features and characteristics of the present invention can be obtained from this. Get a deep and specific understanding, but the attached test: Explicit use: It is not intended to limit the present invention. . Please refer to the fourth figure, which is the circuit diagram of the three-phase half-bridge power factor modification of the present invention. In order to reduce the switch of the conventional power factor corrector, the present invention uses four switching switches as the semi-same circuit architecture of the power factor corrector to save circuit cost and improve overall efficiency. In addition, ^ ^ Ming, in order to obtain high voltage or dual output power, the use of half-bridge circuit input voltage balance control 'solves the problem of input current distortion due to voltage imbalance on the two output capacitors, affecting system performance. The three-phase half-bridge power factor corrector main circuit 1 of the present invention includes: Three-phase power input terminals Va, vb, and Vc are connected to three inductors La, Lb, and Lc, respectively, and two-phase inductors La After Lb and Lb, four fast diodes D1 and D4 are connected in series, and four switching switches S4 and S4 are connected in parallel to the four diodes. The switching switch can use a high power field effect transistor.

1234698 5. Description of the invention (6) (MOSFET), and the capacitors C1 and C2 will be released in the second round. In the main circuit of the corrector, the RL1A and RL2 are connected in parallel with the RL1A and RL2. In the architecture, the switch is boosted by the switch S2 and the diode D1. C1 and pole body 2 constitute a switching boost circuit of the negative half cycle of the group. Yes; JS bu-: power supply, and its switch s [diode D3 with η valley C2 'constitutes another set of positive half-cycle switching boost circuit == 2 off S3, diode D4 is constituted Another set of negative half-cycle switching is based on the above-mentioned switching booster circuit, Va phase and, the purpose: = lightning current can be controlled to have the same phase with the power input voltage of the wheel input sinusoidal input power factor correction iE, While the non-switching booster circuit can control the I-shaped two-phase V c phase input power supply, a three-phase balanced two-phase current waveform can be used to control the current waveform. The principle of dry balance is to analyze the circuit operation principle of the present invention first, assuming that the two are balanced and both are E, and then use the Va phase and Vb phase input electrical properties to distinguish one cycle of the input power supply as (I ) ν > 〇, η <; / (ιι v; > 0, Vb > 0, (melon) va < 0, Vl > 〇, and (Ιγ) 〇, v four working intervals for analysis, as shown in the fifth figure B. Interval I: v 0, v b < 〇

When 0 and vb < 0, the circuit is composed of a group of positive switching switching circuits S2 and D1, and a group of negative switching switching circuits S3 and D4. By switching ON of the switches S2 and S3 / OFF and the principle of three-phase balance of input voltage to find each inductor voltage ', then borrow the inductor voltage and inductor current (here is J

1234698 V. Description of the invention (7) The relationship of the input current) can be used to obtain the slope change of each input current. As shown in Table 1, it is the change of each inductor voltage and the slope of each inductor current of the four kinds of S2 / S3 switching. . Table 1 :

Case switch VVV Hla mb mc 1 S2 OFF S3 OFF E 0-+ | mc | < max {| ma | ， | mt |) 2 S2 OFF S3 ON E / 3 Ξ / 3 -2E / 3--+ 3 S2 ON S3 OFF -E / 3 -E / 3 2Ξ / 3 + +-4 S2 ON S3 ON -EE 0 +-| | mc | < max {| ma |, | mb |} ❹ Note: ma, mb, m is the slope of the phase inductor currents of V a, V b, and V c. It can be seen from Table 1. In the case of Case 1,2 S2 OFF and Case 3, 4 S2 ON, by adjusting the time of S3 0N / 0FF, Control the amount of increase or decrease of the Vb phase input current so that it follows a sinusoidal command current waveform to achieve the purpose of correcting the power factor. Similarly, in the case of Case 1, 3 S3 OFF and Case 2, 4 S3 〇N, borrow By adjusting the time of §2 0N / 0FF, you can control the amount of increase or decrease of the Va phase input current, so that it follows a sinusoidal command current waveform to achieve the purpose of correcting the power factor. As for the Vc phase input current, it is boosted by no switching The circuit can be controlled, so the principle of three-phase balance must be used to indirectly control the current waveform. Interval II: V > 0, V 〇 Similarly, when v > 0 and v b > 〇, the operating circuit of the three-phase half-bridge four-switch power factor corrector is switched by a set of S2 and D1 in the forward direction. Boost circuit,

1234698 Invention description (8) and S4, D3 are another set of forward switching boost circuits. Based on the principles of ON / OFF of the switch S2 and S4 and the three-phase balance of the input voltage ^, the slope of each input current is obtained. The change, as shown in Table 2, is the change of the inductor voltage and the slope of each inductor current of the four kinds of S2 / S4 ^. ' Table 2:

Similarly, when Va < 0 and vb > 〇, the operating circuit of its three-phase half-bridge corrector is S1, D2—the negative direction of the group, and 1 window power factor, and S4, D3—the positive direction of the group. The circuit is composed of #circuit, the principle of ON / OFF of S1 and S4 and the three-phase balance of the input voltage. The slope of the input current is changed by the switch. As shown in the table, it is S1, / S4, and 1 ^.

The slope of the inductor voltage and each inductor current. Each of the 119 switches Table 3:

Page 12 1234698 V. Description of the invention (9)

Case switch VVV mb mc 1 SI OFF S4 OFF -5 E 0 +-| mc | < max (| ma |, | mt |) 2 SI OFF S4 ON -m ^ E / S 2E / 3 + +-3 SI ON S4 OFF Ξ / 3 Ξ / 3 -25/3--+ 4 SI ON S4 ON E -E 0-+ | mt |} Note: ma, mb, and m are respectively the phase inductor currents of Va, Vb, and Vc. Slope interval IV: v a < 〇, v b < 〇 When v a < 0 and v b < 0, the operating circuit of the three-phase half-bridge four-switch power factor corrector is switched from Sb D2—group negative direction Step-up circuit, and S3, D 4— group of negative-direction switching step-up circuit. Based on the principle of ON / OFF of switch s 丨 and 83 and three-phase balance of input voltage, the slope of each input current can be obtained. The change 'is shown in Table 4, which is the change in the slope of each inductor voltage and each inductor current of the four S1 / S3 switches. Table 4:

Case switch VVV ma mb mc 1 SI OFF S3 OFF -E / 3 25/3 + +-2 SI OFF S3 ON -EE 0 +-| πι0 | &lt; ιη &amp; χ {| πι4 |? | Mb |} 3 SI ON S3 OFF B -E 0-+ | mc | <max (| ma |, 4 SI ON S3 ON E / 3 Ξ / 3 -2E / 3--+ Note · ma, mb, and m are V a , V b, V c slope of inductor current

Page 13 1234698 V. Description of the invention (ίο) Comprehensive analysis of the above analysis shows. By switching the four switching switches S1 and S4, the input current waveforms of the V a phase and the V b phase can be controlled to achieve the purpose of power factor correction. Without the Vc phase input power source that can be controlled by the switching booster circuit, Use the principle of three-phase balance to indirectly control its current waveform. In each switching state, when the fast diode is ON, the connected switch can be turned ON or OFF (that is, don't care). Using this relationship, the sixteen switching states (such as Tables 1 to 4) generated between each switch (SI S2, S3, and S4) can be simplified into four switching states in one cycle (not between zones), as shown in Table 5. Shown is the changeover switch (SI S2 S3 S4) 切换 switching state in a cycle, so the complexity of the control circuit can be reduced. Table 5: mamb voltage range + + +-+-I (va &gt; 0, vb &lt; 0) (0 1 0 x) ¢ 0 1 1 0) (x 0 0 x) (x 0 1 0) II (va &gt; 0, Vb &gt; 0) (0 10 1) (0 1x0) (x 0 0 1) (x 0 x 0) III (va &lt; 0, vb &gt; 0) (0x0 1) (0 XK 0) ( 10 0 1) (10x0) IV (va &lt; 0, vb &lt; 0) (Ox Ox) (0x10) (1 OOx) (10 10) One-time period (0 10 1) (0 110) (10 0 1) ( 10 10) Note: In the table, π Γ table switch “0ΝΠ,” 0Π table ”0FFn, π X'1 table ff d ο n, t care, please refer to the sixth figure, which is the current of the present invention The block diagram of the hysteresis control circuit. Based on the foregoing analysis, the present invention specially designs a current hysteresis control

Page 14 1234698 Brief description of the drawings [Simplified description of the drawings] (1) Description of the drawings: The first picture is a circuit diagram of a bridge three-phase rectifier based on a traditional diode; the second picture is the input of the first picture Voltage and current waveform diagrams; the third diagram is a traditional three-phase power factor corrector; the fourth diagram is a circuit diagram of a three-phase half-bridge power factor corrector of the present invention; the fifth diagram is a two-phase input power source of the fourth diagram; The waveform diagrams of each working interval; the sixth diagram is a block diagram of the current hysteresis control circuit of the present invention; the seventh diagram is a circuit diagram of the hysteresis comparator embodiment of the present invention; and the eighth diagram is a proportional integral control circuit of the present invention Example circuit diagram

Va, Vb, Vc La, Lb, Lc D and D4 (2) The main part of the symbol corrector main circuit three-phase power input terminal inductor fast diode switch output load output capacitor input current Sb S4 RU, RL2 Cb C2 i af, i bf

Page 17 1234698 Brief description of the diagram Command current ί a Current hysteresis control circuit 10 Current sensor 11 Step-down transformer 12 Current hysteresis circuit 13 Proportional integral control circuit 14 Balance control circuit 15 Output drive circuit 16 ΗΗ page 18

Claims (1)

Shuangtong M class: Μ 4.; 〇ί Η Case No. 92116192_year month day_ί ±± __ Lack (, two..1 ______________________j ~ ——… six? "Patent scope 1. A three-phase half-bridge Type power factor corrector output voltage balance control device, which is connected to the three-phase power input terminal and includes: a plurality of inductors connected in series to the three-phase power input terminal; and a plurality of diodes connected in series to the two-phase of the inductor 'Form a three-phase half-bridge type multiple power output terminal; a plurality of switching switches connected in parallel to the diode; a plurality of output capacitors connected in parallel to the load of the power output terminal; and a current hysteresis control circuit including : A plurality of current sensors, which are connected in series to two-phase input terminals of the three-phase power input terminal, for changing the two-phase wheel current into a voltage signal; a plurality of step-down transformers whose input terminals are connected to two The phase input terminal is used to generate two command currents with sinusoidal waveforms and the same phase as the input power voltage to make the input current follow; a complex current hysteresis circuit is connected to the current sensor and the The step-down transformer is made by comparing the two-phase input current with the command current to be followed by a hysteresis comparator, and then controlling the four switches for timely switching based on the results; a proportional-integral control circuit connected to The two power output terminals and the 彳 p current hysteresis circuit are used to provide a feedback compensator, which responds to the load output power to control the command current value, so that the output feedback voltage can decrease as the output voltage increases. Or decrease and increase, then the command current will be adjusted accordingly to control the output voltage to achieve the effect of regulated output; and Page 19, 2 · 4 · i No. 921〗 ft1Q9, patent application balance control circuit, is a remote current hysteresis circuit, which is used to envy a at the output end of the two power wheels and the electric scale element due to its own error f = shift The object of electricity repeated or used, the balance control circuit; = the current proportional constant of dust unbalance, and then: first reduce the level of the wheel-in current, as described in the first patent application scope of the three-device wheel-out voltage balance control The device, wherein: the power factor is modified by a positive rate field effect transistor (MOSFET). / 幵 Stomach can use the three-phase half-bridge power factor correction described in item 1 of the high-power range, theft output voltage balance control device, ... step-down transformer, the electric current is separated from the current hysteresis control circuit and the input power. 11 ', electric lice ^ The three-phase half-bridge power factor correction described in item 丨 of the scope of application patents = wheel-out voltage balance control device, wherein the current hysteresis control circuit is an output driving circuit, which is connected to the current magnetism The hysteresis circuit and the four switching switches are inserted into the blanking time in the control signal of the current hysteresis circuit to ensure that the four switching switches will not cause a short circuit due to overlapping U-on periods. The three-phase half-bridge power factor correction as described in item 4 of the scope of patent application is a wheel-out voltage balance control device, wherein the output driving circuit can isolate the ground terminal of the control signal from the ground terminal of the main circuit to prevent The input signal interferes with the control signal of the switch and amplifies the control. Ι2Λ698 —Seven 94. ‘〇1 ::; cable number 92116192 I 〆” a B. "^ Rr? ^ ¥ W Range Signal’ makes it sufficient to trigger the switch. 6. —A kind of current hysteresis control circuit, which is connected to a plurality of switching switches, including: ——— A complex current sensor of a power factor corrector, which is connected in series to the power input terminal &lt; γ ^ power wheel input terminal for Replace the voltage of the complex step-down transformer with electricity to generate a sinusoidal waveform: = number of power input terminals to let the input current follow the command current complex current hysteresis circuit of the same phase, = non-voltage transformer. A Xuewei 乂 The current sensor and the down-flow pass through a hysteresis comparator II_: the knife and the chase will then follow the command to switch the electric switch; "'gen controls the cut according to the result = example Integral control circuit, connected to the hysteresis circuit, is used to increase the output 鳊 and the current power to control the command current Two reaction load input and output 8 + Γ increase and decrease, or decrease and increase, the level of the day to reach the household: straw Control the size of the output power, the effect of q% voltage output; and a single power supply, the output end of the power wheel and the symmetrical element used for the current magnet. The balance proportional constant reduces the input S ί ί 2 to solve the DC bias Power transfer Or make the output voltage imbalance caused by the "Wu difference" multiply by the control circuit to sample the output voltage one by one ~ order 丄 ^ To follow the command current addition to increase or increase the current accuracy Position, so that the output voltage reaches a balance. Page 21 [Lai jjj Case No. 92Π6192 Amendment 6. Patent application scope 7. The current hysteresis control circuit described in item 6 of the patent application scope, further including: an output drive circuit Is connected to the current hysteresis circuit and the changeover switch, and a blank time is inserted into the control signal of the current hysteresis circuit to ensure that the changeover switch will not cause a short circuit due to the heavy on-time period. Page 22