TW201906295A - Isolated floating power conversion system and method thereof - Google Patents

Abstract

A transistor-implemented switch control IC, integrated circuit, and method are invented for isolated floating power conversion system. The system includes a secondary control bus (381) driven by an isolate power controller, which comprises an OSC & logic circuit, an isolate power controller (311, 312) and a number of switches (322, 323, 324, 321, 326, 327, 328, 329). At least one switch circuit (326, 327, 328 and 329) is coupled to the isolate power bus (301, 302). The isolate power controller is operable to provide the control switching signal to the at least one switch circuit to drive the isolate power bus.

Description

Isolated floating power conversion system and method thereof

The present invention relates to a power conversion system, and more particularly to a synchronous driver and an equivalent isolated inductorless high frequency wide transformer having a secondary side center tap coil. The invention also relates to a power conversion method for such a system.

Many power conversion systems include DC/AC and DC/DC isolated charge conversion. In a DC filament drive application, such a power conversion circuit is referred to as a converter, and in an AC filament drive application, referred to as an inverter having an off bias voltage coupled to a secondary side center tap coil. In this application, this cutoff bias can reduce noise in the vacuum display device.

Figure 1 is an example of a conventional power conversion analog system. In this example, a transformer is located between the primary side supply area and the secondary side supply area to achieve voltage conversion and isolation. In a simple conversion circuit for filament drive, the off bias voltage 104 is coupled to the transformer through a center tap of the secondary side coil. At least one switch 102 is rapidly switched under the control of the oscillator 101 to cause current to flow back to the DC source from one end of the transformer 103 through two alternate paths, and the alternating current switching of the primary side coil current generates alternating current (AC) in the secondary side circuit. In some vacuum display applications, a Zenor diode is attached to the center tap coil to form a DC bias.

Figure 2 is a simplified version of the DC output of Figure 1, in which an additional diode bridge 201 and a large capacitor 202 are coupled to the secondary side coil of the transformer to rectify and filter the alternating current.

The present invention can overcome the shortcomings of the prior art and can provide additional added value. The present invention can avoid the use of a bulky, expensive and high-loss, low-frequency wide custom transformer, low-dropout Shottky diode and The environmentally friendly electrolytic capacitor plus the low efficiency power consumption of the class A amplifier, the digital signal processing circuit (DSP) of the present invention, the analog transformer, and the enhanced function that the transformer cannot achieve, can adjust the output power to different VFDs, and is thinner. It is also more energy-efficient and environmentally friendly, achieving the advantages of innovation, uniqueness and difference.

In view of the above-mentioned problems of the prior art, it is an object of the present invention to provide an innovative circuit that uses a plurality of transistors and avoids the use of Schottky diodes and large transformers to isolate the primary side and The secondary side circuit transmits power from the primary side circuit to the secondary side circuit to reduce power loss and component size.

According to one of the objects of the present invention, a power conversion system is proposed, which can be used for AC/DC power conversion of a floating power supply. The system can include an isolated power bus, a charge transfer system, and a product including a plurality of MOS field-effect transistors. Body circuit, wherein the charge transfer system includes an isolated power bus controller; an oscillator that provides a timing signal to the isolated power bus controller; a crossover block bus that provides a delay time signal to the isolated The power bus controller delays the opening time of the plurality of secondary side switches controlled by the isolated power bus controller, wherein after the plurality of primary side switches are turned off, the opening time of the plurality of secondary side switches is delayed by one a preset time interval; a biasing busbar that provides a DC bias to the load equal to the DC bias applied to the central tap coil of the transformer; a primary side control bus that generates a primary side control signal to a plurality of Primary side switch; secondary side control bus which can generate secondary side control signals to a plurality of secondary side switches; a switch circuit that is coupled to the isolated power bus; at least one switch control bus that controls switching of at least one switch circuit and transfers charge to the charge transfer system of the isolated power bus; and at least one switching control A bus bar, which may include at least one quasi-offset to adjust the signal for controlling the secondary side switch.

According to one of the objects of the present invention, a power conversion system is further provided, wherein a switch circuit above the outer loop can be coupled to the upper side of the isolated power bus, and a switch circuit under the outer loop can be coupled to the isolated power bus The lower side, wherein the switch circuit above the outer loop and the switch circuit under the outer loop may comprise a synchronous switch circuit, which can be used to transfer charge to the isolated power bus; the switch circuit of the inner loop in the power inverter application It can be coupled to the underside of the isolated power bus, and the switching circuit under the inner loop can be coupled to the upper side of the isolated power bus, wherein the switching circuit above the inner loop and the switching circuit under the inner loop include a synchronous switch The circuit can be used to transfer charge to the isolated power bus; the switch circuit on the inner loop can be coupled to the upper side of the isolated power bus in the power conversion and isolated data transmission applications, and the switch circuit is connected to the power supply under the inner loop The conversion and isolated data transmission application can be coupled to the underside of the isolated power bus, wherein the switching circuit above the inner loop and the switching power under the inner loop It may include synchronizing switch circuit operable to charge transport isolated power bus.

Wherein, the upper voltage applied to the upper switching circuit and the lower voltage applied to the lower switching circuit are synchronized; the circuit may include at least one bootstrap level converter that offsets the logic level to the secondary side control bus position It is necessary to control the switching of the upper switching circuit and the lower switching circuit.

According to still another object of the present invention, a power conversion method of a switching control integrated circuit realized by a transistor is further proposed, which can be used for an isolated floating power conversion system. The method can include the steps of: implementing a high-density charge transfer system through a double loop, wherein the switch circuit above the outer loop can be coupled to the upper side of the isolated power bus, and the switch circuit can be coupled to the isolated power supply under the outer loop The lower side of the bus bar, wherein the switch circuit above the outer loop and the switch circuit under the outer loop may comprise a synchronous switch circuit for transmitting charge to the isolated power bus; in the power inverter application, the inner loop The upper switching circuit can be coupled to the underside of the isolated power bus, and the switching circuit below the inner loop can be coupled to the upper side of the isolated power bus, wherein the switching circuit and the inner loop are below the inner loop The switching circuit can include a synchronous switching circuit for transferring charge to the isolated power bus; a single loop can output a pulsating DC; in power conversion and isolated data transmission applications, the switching circuit above the inner loop can be coupled to the isolation The power supply busbar is on the upper side, and the switch circuit under the inner loop can be coupled to the underside of the isolated power busbar, wherein the switch circuit and the inner loop under the inner loop The switching circuit above the circle may comprise a synchronous switching circuit for transmitting charge to the isolated power bus; providing at least one switching control bus, which may include a level shifting circuit to offset the potential according to the offset voltage bus The side reference switch controls the level of the busbar to the secondary side switch control busbar.

Additional features and advantages may be realized through the techniques of the present invention, and other embodiments and aspects of the invention described herein are contemplated.

Other features and advantages of the present invention will become more apparent from the description and appended claims.

The embodiments of the isolated floating power conversion system and the method thereof according to the present invention will be described with reference to the related drawings. For the sake of understanding, the same components in the following embodiments are denoted by the same reference numerals.

Figure 3 illustrates a schematic diagram of one embodiment of an isolated floating power conversion system of the present invention having a switching control integrated circuit implemented using a transistor that provides an AC output. The system 30 can include isolated power bus bars 301 and 302, a charge transfer system, and an integrated circuit including a plurality of MOS field-effect transistors, wherein the charge transfer system can include an isolated power bus controller 312 and an oscillator 311. The crossover block bus bar 382, the bias bus bar 383, the primary side control bus bar 384, the secondary side control bus bar 381, at least one switch circuit, at least one switch control bus bar, and at least one switch control bus bar. The oscillator 311 can provide timing signals to the isolated power bus controller 312. The crossover block busbar 382 can provide a delay time signal to the isolated power bus controller 312 to delay the turn-on time of the plurality of secondary side switches 326, 327, 328, 329 controlled by the isolated power bus controller 312. The opening time of the plurality of secondary side switches 326, 327, 328, and 329 may be delayed by a predetermined time interval after the plurality of primary side switches 321, 322, 323, and 324 are turned off. The biasing busbar provides a DC bias to the load 391. The primary side control bus 384 can generate primary side control signals to the primary side switches 321, 322, 323, 324. The secondary side control bus 381 can generate secondary side control signals to the secondary side switches 326, 327, 328, 329. The switch control bus bar can control switching of at least one switching circuit and transfer charge to the charge transfer system of the isolated power bus bars 301, 302. The at least one switching control bus bar can include at least one quasi-offset that can adjust the signals to facilitate operation of the secondary side switches 326, 327, 328, 329.

As shown in FIG. 3, the oscillator 311 generates two phase clocks having crossover cutoff regions which reduce the through distortion, the primary side switching control and the bias voltage to be equivalent to the center tap coil. In phase 1, voltage 371 is directed to waveform factor control capacitor 351 via switches 321, 322, while waveform factor control capacitor 352 injects isolated charge to output load 391 directly through switches 329, 328 controlled by secondary side control bus 381.

As shown in FIG. 3, in phase 2, the alternate path directly controlled by the secondary side control bus 381 passes through the switches 326, 327, the waveform factor control capacitor 351 injects an isolated charge coupled to the output load 391, and the charge 371 passes through the switch. 323, 324 are introduced into the waveform factor control capacitor 352. The alternating current is generated to the load 391 via the alternating of the inner loop and the outer loop current direction. The output rms voltage is a function of switching the duty cycle, capacitance, input voltage, load, and on-resistance of the transistor.

The isolated charge transfer is alternately coupled to the load by the isolated waveform factor control capacitors 351, 352, in some embodiments by a holding capacitor.

In one embodiment, if the charge output is extremely small, circuit 30 can utilize a HV MOS 2M IC foundry process that includes a waveform factor control capacitor. The maximum isolated output is limited by the maximum junction breakdown voltage of this process. P-type MOS transistors are used for switches 321, 323, 326, and 328. If other bootstrap methods are used, they can be replaced by N-type MOS transistors. N-type gold oxide semi-transistors are used for switches 322, 324, 327, 329. The NBL layer is used to maintain isolation.

The switches 326, 327, 328, 329 on the isolated secondary side 381 need to be driven by control pulses of the isolated power bus bars 301, 302. An isolated power controller 312 can perform a level shift of the ground pulse to control the pulses of the secondary side control bus. No current flows between the primary side unbalanced circuit and the secondary side balancing circuit.

This embodiment includes the following steps:

The AC and DC charge transfer system is realized by a double loop, wherein the switch circuit above the outer loop can be coupled to the upper side of the isolated power bus, and the switch circuit under the outer loop can be coupled to the underside of the isolated power bus Wherein, the switching circuit above the outer loop and the switching circuit under the outer loop may comprise a synchronous switching circuit, which can be used for transferring charge to the isolated power bus; in the power inverter application, the switching circuit above the inner loop Can be coupled to the underside of the isolated power bus, and the switching circuit below the inner loop can be coupled to the upper side of the isolated power bus, wherein the switching circuit below the inner loop and the switching circuit above the inner loop can include A synchronous switching circuit that can be used to transfer charge to an isolated power bus; in power conversion and isolated data transmission applications, the switching circuit above the inner loop can be coupled to the upper side of the isolated power bus, while the inner loop The lower switching circuit can be coupled to the underside of the isolated power bus, wherein the switching circuit below the inner loop and the switching circuit above the inner loop can include a synchronous switching circuit A charge transport power to the isolated bus.

The voltage applied to the upper switching circuit is isolated from the voltage applied to the lower switching circuit.

At least one switch control bus is provided, which can include a level shifting circuit to offset the level of the first ground reference switch control bus to the second switch control bus according to the offset voltage bus potential.

Figure 4 is a waveform of the position potential of the filament load of the circuit of Figure 3. The potential at the center point of the load is equal to the potential of the central tap coil of the transformer. For purposes of illustration, the voltage waveform of circuit 30 is equivalent to a transformer having a center tap and a bias connection.

Figure 5 is a schematic illustration of one embodiment of an isolated floating power conversion system of the present invention, which is derived from Figure 3. As shown in FIG. 5, in phase 1, the waveform factor control capacitor 552 injects isolated charge to the output load 591 via the switches 528, 529 and via the inner loop coupling controlled by the secondary side control bus 581, and the circuit is via the switch 521. , 522 takes the primary side charge 571 to the waveform factor control capacitor 524. In phase 2, the circuit draws ground charge 571 to waveform factor control capacitor 552 via switches 523, 524, and the waveform factor control capacitor couples the isolated charge to output load 591 via switches 526, 527 controlled by secondary side control bus 581. Capacitor 592 is used to filter switching noise. The same direction of current through the inner and outer loops produces direct current to the load 591, which is used for synchronous DC converter applications.

As shown in FIG. 6, it incorporates an additional variation in the embodiment of circuit 50 that includes isolation of the loop formed by the interrupting power circuit and a data transmission path having a high impedance relative to other circuit components. Due to the interruption of the loop, the noise voltage is across the isolation barrier, not at the receiving end or more sensitive components.

As shown in FIG. 7, it incorporates additional variations in the embodiment of circuit 30. In high precision power supply applications such as AMVFD, the charge transfer rms value is determined by feedback input power supply 704 and is built into I2C decoder 703. The communication protocol changes the power feedback resistor 702 to change the loop power value 371 as the dynamic control compensation output 391. When the input voltage is fixed, it includes at least one digital pulse width modulation signal processing circuit (DSP) 711 as the adjusted output power P, P = function of (Width of pulse), to different specifications VFD.

The above is intended to be illustrative only and not limiting. Any other equivalent modifications or alterations of the present invention are intended to be included in the scope of the appended claims.

DETAILED DESCRIPTION OF THE INVENTION The detailed construction, operation, and operation of the present invention will now be described in detail with reference to the drawings, which illustrate various embodiments of the invention. FIG. 1 is a schematic diagram of one embodiment of a conventional power conversion apparatus. Figure 2 is a schematic diagram of another embodiment of a conventional power conversion device. Figure 3 is a schematic diagram of one embodiment of an isolated floating power conversion system having a switching control integrated circuit implemented using a transistor, which provides an AC output and a pulsating DC output. Figure 4 is a waveform diagram of the circuit of Figure 6. Figure 5 is a schematic illustration of another embodiment of an isolated floating power conversion system of the present invention that provides a synchronous DC output. Figure 6 is a schematic diagram of a digital isolator of another embodiment of the isolated floating power conversion system of the present invention, which provides synchronous DC output and data transmission.

Claims (10)

A power conversion system for converting a power source of a floating power source into an AC/DC isolated power source, comprising an isolated power bus, a charge transfer system, and an integrated circuit including a plurality of MOS field-effect transistors, wherein the charge transfer The system consists of: an isolated power bus controller; an oscillator that provides timing signals to an isolated power bus controller; a crossover block bus that provides a delay time signal to the isolated power bus controller for delay The opening time of the plurality of secondary side switches controlled by the isolated power bus controller, wherein, after the plurality of primary side switches are turned off, the opening time of the plurality of secondary side switches is delayed by a preset time interval; The busbar provides a DC bias to the load, which is equivalent to the DC bias applied to the central tap coil of the transformer; the primary side control busbar generates a primary side control signal to a plurality of primary side switches; The busbar generates a secondary side control signal to a plurality of secondary side switches; at least one switching circuit is connected to each other Type power bus coupling; at least one switch control bus is a charge transfer system that controls switching of at least one switch circuit and transfers charge to the isolated power bus; and at least one switch control bus includes at least one quasi-bias The shifter adjusts the signal to facilitate the operation of the secondary side switch. The power conversion system of claim 1, wherein the at least one switching circuit comprises at least one transistor switching circuit, and wherein the voltage input system comprises a source input input to the at least one transistor switching circuit or The drain input, and the primary side control signal and the secondary side control signal comprise a gate input input to at least one of the transistor type switching circuits. The power conversion system of claim 2, wherein at least one of the switching circuits comprises an upper switching circuit and a lower switching circuit; and the upper switching circuit comprises at least one P-type transistor circuit or N-type transistor circuit, and the lower switch The circuit system includes at least one N-type transistor circuit, and wherein the upper switch circuit and the lower switch circuit form a charge transfer loop circuit. At least one of the switching circuits includes a level shifter circuit to offset the level of the primary side-to-ground reference switch control busbar to the secondary side switch control busbar according to the offset voltage busbar potential. The power conversion system of claim 1, wherein the power conversion system comprises a charge transfer system and an isolated data transmission system, and wherein the charge output of the device is across the isolated power bus. Wherein the charge transfer system includes at least one waveform factor control capacitor that alternately transfers charge directly to the output. The bias busbar traverses the isolated power bus via a plurality of switches. A power conversion system includes: a switch circuit above the outer loop and a switch circuit under the outer loop; the switch circuit above the outer loop is coupled to the upper side of the isolated power bus, and the switch circuit under the outer loop Coupling to the underside of the isolated power bus, wherein the switch circuit above the outer loop and the switch circuit under the outer loop include a synchronous switch circuit for transferring charge to the isolated power bus; above the inner loop The switching circuit and the switching circuit under the inner loop, the switching circuit above the inner loop in the power inverter application is coupled to the lower side of the isolated power bus, and the switching circuit under the inner loop is coupled to the isolated power bus The upper side, wherein the switching circuit above the inner loop and the switching circuit under the inner loop comprise a synchronous switching circuit for transferring electric charge to the isolated power bus; and the switching circuit of the inner loop for power conversion and isolation The data transmission application is coupled to the upper side of the isolated power bus, and the switching circuit under the inner loop is coupled to the isolated power in the power conversion and isolated data transmission applications. a lower side of the busbar, wherein the switching circuit above the inner loop and the switching circuit under the inner loop comprise a synchronous switching circuit for transmitting charge to the isolated power bus; wherein, the upper switching circuit and the lower switching circuit When turned off, the voltage applied to the upper switching circuit and the voltage applied to the lower switching circuit are isolated, and the secondary side control bus circuit is used to control the upper switching circuit and the lower switching circuit. The power conversion system of claim 5, wherein the power conversion system includes a charge transfer system including at least one quasi-offset driver circuit and at least one waveform factor capacitance factor control capacitor to extract energy in a fixed time interval . The circuit includes at least one bootstrap level converter that offsets the logic level to the secondary side control bus level to control the switching of the upper switching circuit and the lower switching circuit. A power conversion method includes the following steps: A. Implementing an AC and DC charge transfer system by using a double loop, wherein the switch circuit above the outer loop is coupled to the upper side of the isolated power bus, and the switch under the outer loop The circuit is coupled to the underside of the isolated power bus, wherein the switching circuit above the outer loop and the switching circuit under the outer loop comprise a synchronous switching circuit for transmitting charge to the isolated power bus; In a variable application, the switching circuit above the inner loop is coupled to the underside of the isolated power bus, and the switching circuit below the inner loop is coupled to the upper side of the isolated power bus, wherein the switch below the inner loop The switching circuit on the circuit and the inner loop includes a synchronous switching circuit for transferring charge to the isolated power bus. In the power conversion and isolated data transmission applications, the switching circuit above the inner loop is coupled to the isolated power supply. The upper side of the bus bar, and the switching circuit under the inner loop is coupled to the lower side of the isolated power bus, wherein the switch circuit and the inner loop are opened under the inner loop The off circuit includes a synchronous switch circuit for transferring charge to the isolated power bus; B. exposing that the voltage applied to the upper switch circuit and the voltage applied to the lower switch circuit are isolated from the primary side; and C. providing at least A switch control busbar includes a level shifting circuit to offset the level of the primary side-to-ground reference switch control busbar to the secondary side switch control busbar according to the offset voltage busbar potential. D. providing at least one resistor row connected to the primary side loop power supply, comprising at least one switch control busbar for receiving a command of the serial decoder to change the overall voltage dividing resistance value, thereby changing the voltage of the primary and secondary sides value. When the input voltage is fixed, it includes at least one digital pulse width modulation signal processing circuit (DSP) as the adjusted output power. The power conversion method of claim 5, wherein the charge transfer system further comprises at least one bootstrap level offset circuit. Wherein the charge transfer system further comprises at least one waveform factor control capacitor to alternately directly transfer the coupled energy to the output. The power conversion method of claim 5, wherein the bias busbar is applied to the isolated power bus via a plurality of switches. At least one of the switching circuits includes an upper switching circuit and a lower switching circuit, the upper switching circuit includes at least one P-type transistor circuit or an N-type transistor circuit, and the lower switching circuit includes at least one N-type transistor circuit, and wherein The upper switching circuit and the lower switching circuit include a charge transfer loop circuit. For example, in the power conversion method described in claim 5, the charge transfer system is implemented by using a double loop, wherein the switch circuit above the outer loop is coupled to the upper side of the isolated power bus, and the switch circuit is coupled under the outer loop. To the underside of the isolated power bus, wherein the switch circuit above the outer loop and the switch circuit under the outer loop include a synchronous switch circuit for transferring charge to the isolated power bus; in the power inverter application, The switching circuit above the inner loop is coupled to the underside of the isolated power bus, and the switching circuit under the inner loop is coupled to the upper side of the isolated power bus, wherein the switching circuit and the inner loop above the inner loop The lower switching circuit includes a synchronous switching circuit for transferring charge to the isolated power bus. In the power conversion and isolated data transmission applications, the switching circuit above the inner loop is coupled to the upper side of the isolated power bus. The switching circuit under the inner loop is coupled to the underside of the isolated power bus, wherein the switching circuit under the inner loop and the switching circuit above the inner loop comprise synchronously open a circuit for transferring charge to an isolated power bus; in a VFD application for high precision power applications, providing at least one resistor bank coupled to the primary side loop power supply, comprising at least one switch control bus for receiving For example, the I2C/SPI serial decoder instruction changes the overall voltage divider resistance value, thereby changing the primary side and secondary side output voltage values. When the input voltage is fixed, it includes at least one digital pulse width modulation signal processing circuit (DSP) to adjust the output power to different VFDs.