TW201414171A - Single-phase three-wire three-port power converter system - Google Patents

Abstract

A single-phase three-wire three-port power converter system includes a three-port power converter, a high DC voltage input/output port, a low DC voltage input/output port and an AC input/output port. The circuit configuration includes a bridge power converter, a filter inductor set, a de-couple circuit, a filter capacitor set, and a controller. The high DC voltage input/output port connects to a DC voltage source. The DC voltage source is selected from a DC power source converted by a DC power converter, a solar cell array or high voltage DC bus. The low DC voltage input/output port connects to a DC voltage source. The DC voltage source is selected from a solar cell array, a fuel cell, a battery set or low DC bus. The AC input/output port connects to the single-phase three-wire utility through a switch set and a load set connected between the AC input/output port and the switch set. The three-port power converter is operated to convert power among the high DC voltage input/output port, the low DC voltage input/output port and the AC input/output port.

Description

Single-phase three-wire three-turn electric energy conversion system

The invention relates to a single-phase three-wire three-turn electric energy conversion system; in particular, a single-phase three-wire three-turn electric energy conversion system has a high-voltage DC input/output port, a low-voltage DC input/output port, and an AC input/output. port.

In general, in a solar power generation system or a fuel cell power generation system, since both the solar cell array and the fuel cell have a large output voltage variation range and the output voltage of the fuel cell is low, both of the commercial parallel power generation systems use two. A class electric energy converter comprising a primary DC-DC electrical energy converter and a primary DC-AC electrical energy converter.

A conventional power conversion circuit, such as the power conversion circuit of the Republic of China Patent No. I327812 and its control circuit and invention patent, as shown in FIG. 1, discloses a schematic diagram of the structure of the power conversion circuit 1. Referring to FIG. 1, the power conversion circuit 1 includes a step-down converter 11, a bypass passive switching element 12, and a continuous-current AC converter 13. The power conversion circuit 1 only has a power flow in one direction, so a battery charger needs to be added during charging, and the low voltage DC voltage is first converted into a high voltage DC voltage during discharge, and then converted into AC power by the high voltage DC voltage. Therefore, its discharge must be converted by two stages, which inevitably causes a large energy loss.

Another conventional power conversion circuit, such as the online uninterruptible power supply device of the Republic of China Patent Publication No. I363464 shown in FIG. 2, is an invention patent, which discloses a schematic diagram of the architecture of the online uninterruptible power supply device 2. Referring to FIG. 2, the online uninterruptible power supply device 2 includes a filtering device 21, a rectifying device 22, a battery device 23, a tamper switch 24, a DC/DC converter device 25, and a DC/AC A switching device 26, a relay 27 and a filtering device 28. Since the online uninterruptible power supply device 2 must pass the DC/DC conversion device 25 and the DC/AC conversion device 26, the DC power of the low voltage battery can be The source is converted into an AC power source, and the DC/DC converter device 25 has a high frequency isolation transformer. This circuit must use a large number of power switching elements and power diodes, thereby causing an increase in equipment cost, and the battery discharge must pass two Stage conversion and transformers will inevitably result in large energy losses.

The above-mentioned patent applications of the Republic of China Patent Publication No. I327812 and No. I363464 are only for reference to the technical background of the present invention and the state of the art is not intended to limit the scope of the present invention.

In view of the above, the present invention provides a single-phase three-wire three-turn power conversion system having a high-voltage DC input/output port, a low-voltage DC input/output port, and an AC input/output port, in order to solve the above problems. There is no need to use an isolation transformer to improve the technical shortcomings of conventional power conversion systems.

The main object of the present invention is to provide a single-phase three-wire three-turn power conversion system having a high-voltage DC input/output port, a low-voltage DC input/output port, and an AC input/output port to achieve a simplified power conversion system. Circuits and the purpose of improving the efficiency of electrical energy conversion.

In order to achieve the above object, a single-phase three-wire three-turn power conversion system according to a preferred embodiment of the present invention includes: a bridge type power converter including a first arm, a second arm, a third arm, and a capacitor arm. Each of the first arm, the second arm and the third arm is formed by two power electronic switches connected in series, the capacitor arm being formed by two capacitors connected in series; a high voltage DC input/output port having a first end point and a second end point, the first end point and the second end point are connected to both ends of the capacitor arm, and the first end point and the second end point of the high voltage DC input/output port are further connected to a high voltage DC input / output voltage source; a filter inductor group, which is composed of a plurality of inductors, and the filter inductor group has a first side and a second side, and the power of the first arm, the second arm and the third arm The series connection of the electronic switch is respectively connected to the first side of the filter inductor; a low voltage DC input/output port has a first end point and a second end point, and the low voltage DC input/output port is first The end point and the second end are connected to the first arm and the second arm via a second side of the filter inductor, and the end point and the second end of the low voltage DC input/output port are further connected to a low voltage DC input An output voltage source; a decoupling loop having a first end point, a second end point, and a third end point, wherein the first end point and the second end point of the decoupling loop are respectively connected to the low voltage DC a first end and a second end of the input/output port for separating the DC and AC current components of the output currents of the first arm and the second arm; an AC input/output port having a first end a first end of the AC input/output port is connected to the third end of the decoupling loop, and the second end of the AC input/output port is connected to the point, the second end point and the third end point a series connection of two capacitors of the capacitor arm, the AC input/output埠The third end is connected to the series connection of the power electronic switch of the third arm via the second side of the filter inductor group, and the first end point, the second end point and the third end point of the AC input/output port Further connected to a load group and a switch group, the switch group is further connected to a single-phase three-wire power distribution system; a filter capacitor group includes at least one capacitor, and the filter capacitor group is connected to the AC input/output port. a first end point, a second end point, and a third end point; and a controller for controlling a power electronic switch of the bridge power converter to achieve a desired function; wherein the capacitor arm is used Energy buffer.

The power electronic switch of the preferred embodiment of the invention is selected from a semiconductor switch.

In the preferred embodiment of the present invention, the decoupling loop is formed by connecting two capacitors in series, and the two ends of the two capacitors are respectively the first end point of the decoupling loop and a second end point, and the series junction of the two capacitors is the third end of the decoupling loop.

The high voltage DC input/output voltage source of the preferred embodiment of the present invention may be a power source converted by a power converter, a solar cell array or a high voltage DC bus.

The low voltage DC input/output voltage source of the preferred embodiment of the present invention may be a solar cell array, a fuel cell, a battery pack or a low voltage DC bus.

The controller of the preferred embodiment of the present invention generates a control signal for performing the load balancing, active power filter and the low voltage DC input/output voltage source when the mains is normal. Charging or discharging function.

In the preferred embodiment of the invention, the controller generates a control signal to cause the single-phase three-wire three-turn power converter to perform an uninterruptible power supply function when the mains is powered off.

In order to fully understand the present invention, the preferred embodiments of the present invention are described in detail below and are not intended to limit the invention.

The single-phase three-wire three-turn power conversion system of the preferred embodiment of the present invention is applicable to various green power generation systems (for example, a solar power generation system or a fuel cell power generation system) or a commercial parallel power generation system, but it is not intended to limit the present invention. The scope.

Referring to FIG. 3, the single-phase three-wire three-turn power conversion system 3 of the preferred embodiment of the present invention includes a single-phase three-wire three-turn power converter 31, a high-voltage DC input/output voltage source 32, and a low voltage. A DC input/output voltage source 33, a load group 34, a switch group 35, and a single phase three-wire power distribution system 36. The single-phase three-wire three-turn power converter 31 includes a high voltage DC input/output port 311, a bridge type power converter 312, a filter inductor group 313, a decoupling circuit 314, a low voltage DC input/output port 315, and a Filter capacitor group 316, one AC input/output port 317 and a controller 318. The single-phase three-wire three-turn power converter 31 includes a first arm 3122, a second arm 3123, a third arm 3124, and a capacitor arm 3121. Each of the first arm 3122, the second arm 3123, and the first The three arms 3124 are formed by connecting two power electronic switches in series, and the capacitor arm 3121 is formed by connecting two capacitors in series.

If the low voltage DC input/output voltage source 33 is a battery pack, the high voltage DC input/output voltage source 32 is a solar cell array composed of a DC-DC boost converter, the single phase three-wire three-turn power The function performed by the converter 31 is to charge/discharge the battery pack, adjust the DC bus voltage, and filter out the harmonic current and the uninterruptible power supply of the load group 34, and when the mains is normal, the single-phase three-wire three-turn electric energy conversion The loader 31 also performs balancing of the load group 34. The first arm 3122 and the second arm 3123 of the single-phase three-wire three-turn power converter 31 respectively adopt a current control type to generate a DC current component and an AC current component. The DC current component and the AC current component can be separated by the decoupling circuit 314, and the single-phase three-wire three-turn power converter 31 can simultaneously control the DC current component and the AC current component to achieve different functions to avoid using multiple A power converter so it simplifies the overall power circuit. The output currents i ₁ and i ₂ of the first arm 3122 and the second arm 3123 of the single-phase three-wire three-turn power converter 31 can be expressed as: i ₁ = i _d1 + i ₁ (1)

i ₂ = i _d2 + i _c2 (2)

Where i _d1 and i _d2 are DC current components, and i _c1 and i _c2 are AC current components. i _d1 is the same size as i _d2 , but its phase is opposite, it will flow through the battery pack, and its current direction is bidirectional to charge/discharge the battery pack; the two AC current components are the same size and the same phase.

The alternating current component will pass through the decoupling loop 314. After passing through the decoupling loop 314, the two alternating currents add up to the sum of the filtered current i _cf1 , the mains current i _{s, L1} and the load currents i _{L, L1} . When the single-phase three-wire three-turn power converter 31 performs the active power filter function, the compensated mains current is a sine wave current, and the phase is in phase with the mains voltage, by controlling the single-phase three-wire three The high voltage DC input/output 埠 311 voltage V _{dc of the} 电能 type power converter 31 can adjust the mains current amplitude. When the high voltage DC input/output 埠 311 voltage V _{dc is} greater than the set voltage, the mains current amplitude must be reduced; conversely, when the high voltage DC input/output 埠 311 voltage V _{dc is} less than the set voltage, the mains current amplitude must be increased, the mains The amplitude of the current can be positive or negative, which determines whether the injected electrical energy is supplied to the mains or supplied by the mains. The voltage of the single-phase three-wire power distribution system 36 can be expressed as: v _{s , L 1 N} = V _s sin ωt (3)

V _s , _{L 2 N} =- V _s sin ωt (4)

The output currents i ₁ and i ₂ of the first arm 3122 and the second arm 3123 of the single-phase three-wire three-turn power converter 31 can be rewritten as: i ₁ = i _b +( i _{cf 1} + i _{L , L 1} - I ₁ sin( ωt ))/2 (5)

i ₂ =- i _b +( i _{cf 1} + i _{L , L 1} - I ₁ sin( ωt ))/2 (6)

Where i _b is the electric/discharge current of the battery pack, which is the DC component of the output currents i ₁ and i ₂ of the first arm 3122 and the second arm 3123, and the second term on the right side of the equations (5) and (6) is The alternating current components of the output currents i ₁ and i ₂ of the first arm 3122 and the second arm 3123. The output current i _{3 of the} third arm 3124 is not connected to the battery pack, so it does not contain a DC component, so that: i ₃ = i _{cf 2} + i _{L , L 2} + I ₁ sin( ωt ) (7)

The high voltage DC input/output 埠 311 voltage V _{dc of} the single-phase three-wire three-turn power converter 31 must be higher than twice the peak value of the capacitor voltage of the single-phase three-wire power distribution system 36 and the decoupling circuit 314. The two capacitor voltages of the decoupling loop 314 can be expressed as: v _{c 1} = V _b /2+ i _{c 1} Z _C (8)

v _{c 2} =- V _b /2+ i _{c 2} Z _C (9)

Where V _b is the battery voltage, Z _C is the impedance of capacitors C _c1 and C _c2 , and i _c1 and i _c2 are the second term on the right side of equations (5) and (6). Therefore, the high voltage DC input/output 埠 311 voltage V _{dc of} the single-phase three-wire three-turn power converter 31 will be higher than the DC bus voltage of the conventional half-bridge power converter.

Referring to FIG. 4A, when the commercial power is normal, the single-phase three-wire three-turn power converter 31 adopts a block diagram of a control unit 4. The control unit 4 includes a current controller 41, a first PWM circuit 42, a current controller 43, and a second PWM circuit 44.

Referring to FIG. 3 and FIG. 4A, the current controller 41 is configured to control the output current of the first arm 3122 and the second arm 3123, and the current controller 41 includes a DC component controller 411 and a voltage control. The device 412, an AC component controller 413, and a current feedback controller 414. The DC component controller 411 is configured to control a DC component of an output current of the first arm 3122 and the second arm 3123, and the voltage controller 412 is configured to control the high voltage DC input/output port 311 voltage V _dc , and the AC component control The controller 413 is configured to control the AC component of the output current of the first arm 3122 and the second arm 3123. The current feedback controller 414 is configured to implement feedback control of the output current of the first arm 3122 and the second arm 3123. The first PWM circuit 42 is configured to generate driving signals of the power electronic switches of the first arm 3122 and the second arm 3123. The current controller 43 is configured to control the output current of the third arm 3124, and the second PWM circuit 44 is configured to generate a driving signal of the power electronic switch of the third arm 3124.

Referring to Figures 3 and 4A again, the battery pack adopts a constant current/constant voltage [CC/CV] charging method, and the first arm 3122 and the second arm 3123 of the single-phase three-wire three-turn power converter 31 are used. In the current control mode, the reference current signals of the first arm 3122 and the second arm 3123 both include a DC component and an AC component. After the battery pack voltage is detected by a voltage detector, the battery pack voltage and the preset voltage are sent to a subtractor, the output of the subtractor is sent to a proportional integral controller I, and the output is sent to a limiter to limit The charging current of the battery pack. Then, the output of the limiter is sent to a unity gain inverting amplifier, and the output of the limiter and the output of the inverting amplifier are the DC components i ^* _d1 and i ^* _d2 of the reference current signal. When the battery pack voltage is lower than the preset voltage, the output value of the proportional integral controller I will continue to increase until the limit value of the limiter is reached. Therefore, the limiter can limit the magnitude of the DC components i ^* _d1 and i ^* _d2 , and the limiter of the limiter is the charging current for constant current charging. When the battery pack voltage reaches the preset voltage, the output value of the proportional integral controller I will continue to decrease, and the output of the proportional integral controller I will be lower than the limit value of the limiter, therefore, the battery pack charging mode The constant current charging mode is switched to the constant voltage charging mode, so the charging current continues to decrease. The preset voltage is a constant voltage value when the battery pack is in a constant voltage charging mode.

The AC component of the reference current signal, as shown in the second term on the right side of equations (5) and (6), includes the mains current, load current, and filter capacitor current. The voltage of the single-phase three-wire power distribution system 36 is detected by the voltage detector and sent to a phase-locked circuit to generate a unit sine wave signal in phase with the mains voltage V _{s, L1N} . The unit sine wave signal is a commercial power. The desired waveform of the current. The high voltage DC input/output 埠 311 voltage V _dc is detected by the voltage detector and sent to a comparator, and the error signal output by the comparator is sent to a proportional integral controller II, and the proportional integral controller II The output is the amplitude of the desired mains current. The output signal of the phase lock circuit is sent to a multiplier by the output signal of the proportional integral controller II to obtain a desired mains current signal. The filter capacitor current is proportional to the micro-voltage of the mains voltage, so the detected mains voltage is sent to a low-pass filter, and the output is sent to a differentiator to obtain the filter capacitor current. The function of the low-pass filter is to filter the switching harmonics. The wave has a cutoff frequency set at 1 kHz, which is much higher than the fundamental frequency of the mains, so the phase shift at the fundamental wave frequency is small. The desired mains current and the filter capacitor current are sent to a subtractor, and the output of the subtractor and the load current i _{L, L1} are sent to an adder by a current detector, and the output is sent to a gain of 0.5. The amplifier, whose output is the AC components i ^* _c1 and i ^* _c2 of the reference current signal.

The sum of the AC component i ^* _{c1 of the} reference current signal and the DC component i ^* _d1 is the reference current signal of the first arm 3122, and the sum of the AC component i ^* _c2 and the DC component i ^* _d2 is the reference of the second arm 3123. The current signal, after the output current of the first arm 3122 and the second arm 3123 is detected by the current detector, the reference current signals of the first arm 3122 and the second arm 3123 are respectively sent to a comparator, the comparator The outputs are sent to two current controllers I and II respectively, and the outputs of the current controllers I and II are sent to the first PWM circuit 42 to generate the power electronic switches S _{1a of} the first arm 3122 and the second arm 3123. , S _1b , S _2a , S _2b drive signals.

As shown in the formula (7), the reference current signal of the third arm 3124 is only an alternating current component, which includes the main current, the load current and the filter capacitor current, and the two filter capacitors C _f1 and C _{f2 have} the same capacitance value, and the expectation of L ₂ mains current L ₁ is opposite, and therefore, it is desirable that the first arm and the second arm 3123 3122 control circuits of the mains current and the filter capacitance current is subtracted by the subtractor, is sent to a gain inverting amplifier of the load The currents i _{L, L2} are detected by the current detector and sent to an adder by the output of the inverting amplifier to obtain a reference current signal of the third arm 3124. The output current i ₃ of the third arm 3124 after the detection of the current detection signal with a reference current supplied to a comparator, comparing the result to a current controller III, III of the current controller to the output of the second PWM The circuit 44 generates a drive signal for the power electronic switches S _3a and S _3b of the third arm 3124.

Referring to FIG. 4B, in the event of a mains failure, the single-phase three-wire three-turn power converter 31 employs a block diagram of a control unit 5. The control unit 4 includes a current controller 51, a first PWM circuit 52, a voltage controller 53, and a second PWM circuit 54.

Referring to FIG. 3 and FIG. 4B again, the current controller 51 is configured to control the output current 1 of the first arm 3122 and the second arm 3123, and the current controller 51 includes a DC component controller 511 and an AC. The component controller 512 and a current feedback controller 513. The DC component controller 511 is configured to control the DC component of the output current of the first arm 3122 and the second arm 3123. The AC component controller 512 is configured to control the output current of the first arm 3122 and the second arm 3123. Flow components. The current feedback controller 513 is configured to implement feedback control of the output currents of the first arm 3122 and the second arm 3123. The first PWM circuit 52 is configured to generate driving signals of the power electronic switches of the first arm 3122 and the second arm 3123. The current controller 53 is configured to control the output current of the third arm 3124, and the second PWM circuit 54 is configured to generate a driving signal of the power electronic switch of the third arm 3124.

Referring to FIGS. 3 and 4B again, when the single-phase three-wire power distribution system 36 fails, the single-phase three-wire three-turn power converter 31 converts the DC power generated by the solar array and the power of the battery pack into an alternating current. The sinusoidal voltage is used to provide electrical energy to the load group 34 (which includes loads I, II, and III). The reference current signals of the first arm 3122 and the second arm 3123 also include a DC component and an AC component, and the discharge current of the battery pack is used to adjust the high voltage DC input/output port 311 voltage V _dc . The high voltage DC input/output 埠 311 voltage V _dc is detected by a voltage detector and sent to a comparator, and the output of the comparator is sent to a proportional integral controller I to obtain a reference discharge current of the battery pack. The proportional integral controller I is supplied to an inverting amplifier having a gain of 1, and the outputs of the proportional integral controller I and the inverting amplifier are DC components i ^* _d1 and i ^* _d2 of the reference current signal.

In theory, the sum of the AC components of the reference current signals of the first arm 3122 and the second arm 3123 is the same as the reference current signal of the third arm 3124, and theoretically includes the load current and the filter capacitor current. In order to obtain a high quality output voltage, a voltage control loop is additionally combined into the reference current signal calculation. The single-phase three-wire load voltages v _{L, L1N} and v _{L, L2N} are detected by the voltage detector and sent to the RMS circuit to obtain the load voltage RMS value, and the detected RMS value and the reference value are sent to a comparator, The output of the comparator is sent to the two proportional integral controllers II and III respectively. After the mains failure, a 60 Hz unit sine wave is generated by a phase lock circuit, and the proportional integral controller II and the output of the phase lock circuit are sent to The multiplier is multiplied to obtain the output voltage v _{L, L1N} reference voltage signal, and the phase lock circuit is also sent to an inverting amplifier of unity gain, and the output of the proportional integral controller III and the output of the inverting amplifier are sent to A multiplier to obtain an output voltage v _{L, L2N} reference voltage signal. The two reference voltage signals and the two load voltage signals are sent to the comparator, and the comparison result is sent to an amplifier with magnifications K ₁ and K ₂ to obtain the output of the voltage control loop. The load currents i _{L, L1} and i _{L, L2} are detected by the current detector, the load voltage v _{L, the L1N} signal is passed through a low pass filter, and the output of the low pass filter is sent to a differentiator to obtain a filter capacitor current. . The amplifier with the magnification K ₁ and the load current i _{L , the L1} signal and the filter capacitor current are sent to the adder, and are passed through an amplifier with a magnification of 0.5 to obtain the reference current signals of the first arm 3122 and the second arm 3123. The AC component adds the AC component of the first arm 3122 and the second arm 3123 reference current signal to the DC component to obtain reference current signals i ^* _c1 and i ^* _{c2 of} the first arm 3122 and the second arm 3123. The output currents of the first arm 3122 and the second arm 3123 are detected by the current detector and sent to the comparator by two reference current signals, and the comparison results are respectively sent to the two current controllers I and II, and the current controller I The output of II and II is sent to the first PWM circuit 52 to generate driving signals for the power electronic switches S _1a , S _1b , S _2a , S _2b of the first arm 3122 and the second arm 3123.

The amplifier output with the magnification K ₂ and the load current i _{L, the L2} signal and the filter capacitor current are added by the adder to obtain the reference current signal of the third arm 3124, and the output current of the third arm 3124 is passed through the current detector. After the detection, the reference current signal is sent to a comparator, and the comparison result is sent to the current controller III, and the output of the current controller III is sent to the second PWM circuit 54 to generate the power electronic switch S _{3a of} the third arm 3124 and S _3b drive signal.

The foregoing preferred embodiments are merely illustrative of the invention and the technical features thereof, and the techniques of the embodiments can be carried out with various substantial equivalent modifications and/or alternatives; therefore, the scope of the invention is subject to the appended claims. The scope defined by the scope shall prevail.

1‧‧‧Power conversion circuit

11‧‧‧Step-down converter

12‧‧‧ Bypass passive switching components

13‧‧‧DC to AC converter

2‧‧‧Online uninterruptible power supply unit

21‧‧‧Filter device

22‧‧‧Rectifier

23‧‧‧ battery device

24‧‧‧矽Switch

25‧‧‧DC/DC converter

26‧‧‧DC/AC converter

27‧‧‧ Relay

28‧‧‧Filter device

3‧‧‧Single-phase three-wire three-turn electric energy conversion system

31‧‧‧Single-phase three-wire three-turn power converter

311‧‧‧High-voltage DC input/output埠

312‧‧‧ Bridge Power Converter

3121‧‧‧Capacitor arm

3122‧‧‧First arm

3123‧‧‧second arm

3124‧‧‧ third arm

313‧‧‧Filter inductor group

314‧‧‧Decoupling loop

315‧‧‧Low-voltage DC input/output埠

316‧‧‧Filter Capacitor Set

317‧‧‧AC input/output埠

318‧‧‧ Controller

32‧‧‧High voltage DC input/output voltage source

33‧‧‧Low-voltage DC input/output voltage source

34‧‧‧Load group

35‧‧‧ switch group

36‧‧‧Single-phase three-wire power distribution system

4‧‧‧Control unit

41‧‧‧ Current controller

411‧‧‧DC component controller

412‧‧‧Voltage controller

413‧‧‧ AC component controller

414‧‧‧current feedback controller

42‧‧‧First PWM circuit

43‧‧‧ Current controller

44‧‧‧Second PWM circuit

5‧‧‧Control unit

51‧‧‧ Current controller

511‧‧‧DC component controller

512‧‧‧ AC component controller

513‧‧‧ Current feedback controller

52‧‧‧First PWM circuit

53‧‧‧Voltage controller

54‧‧‧Second PWM circuit

Figure 1: Schematic diagram of the power conversion circuit of the Republic of China Patent No. I327812.

Figure 2: Schematic diagram of the architecture of the online uninterruptible power supply unit of the Republic of China Patent No. I363464.

Figure 3 is a block diagram showing the architecture of a single-phase three-wire three-turn power conversion system in accordance with a preferred embodiment of the present invention.

Figure 4A: A block diagram of a single-phase three-wire three-turn power converter in accordance with a preferred embodiment of the present invention when the utility power is normal.

Figure 4B: In the case of mains power outage, the single phase three-wire three-turn power converter of the preferred embodiment of the present invention employs a block diagram of the control unit.

3‧‧‧Single-phase three-wire three-turn electric energy conversion system

31‧‧‧Single-phase three-wire three-turn power converter

311‧‧‧High-voltage DC input/output埠

312‧‧‧ Bridge Power Converter

3121‧‧‧Capacitor arm

3122‧‧‧First arm

3123‧‧‧second arm

3124‧‧‧ third arm

313‧‧‧Filter inductor group

314‧‧‧Decoupling loop

315‧‧‧Low-voltage DC input/output埠

316‧‧‧Filter Capacitor Set

317‧‧‧AC input/output埠

318‧‧‧ Controller

32‧‧‧High voltage DC input/output voltage source

33‧‧‧Low-voltage DC input/output voltage source

34‧‧‧Load group

35‧‧‧ switch group

36‧‧‧Single-phase three-wire power distribution system

Claims (8)

A single-phase three-wire three-turn power conversion system includes: a bridge type power converter, comprising a first arm, a second arm, a third arm, and a capacitor arm, each of the first arm and the second The arm and the third arm are formed by two power electronic switches connected in series, the capacitor arm being formed by connecting two capacitors in series for energy buffering; a high voltage DC input/output port having a first end point and a first a second end point, the first end point and the second end point are connected to both ends of the capacitor arm, and the first end point and the second end point of the high voltage DC input/output port are further connected to a high voltage DC input/output a voltage source; a filter inductor group, which is composed of a plurality of inductors, and the filter inductor group has a first side and a second side, and the first arm, the second arm and the third arm are powered by electronic switches The series connection is respectively connected to the first side of the filter inductor; a low voltage DC input/output port having a first end point and a second end point, the first end of the low voltage DC input/output port and a second end is connected to the first arm via a second side of the filter inductor a second arm, wherein the first end and the second end of the low voltage DC input/output port are further connected to a low voltage DC input/output voltage source; a decoupling loop having a first end and a second end a first end and a second end of the decoupling loop are respectively connected to the first end and the second end of the low voltage DC input/output port for the first arm and the third end The DC output current of the two arms is separated from the AC current component; an AC input/output port having a first end point, a second end point, and a third end point, the first end point of the AC input/output port Connected to a third end of the decoupling loop, the second end of the AC input/output port is connected to a series connection of two capacitors of the capacitor arm, and the third end of the AC input/output port is filtered by The second side of the inductor group is connected to the series connection of the power electronic switch of the third arm, and the first end point, the second end point and the third end point of the AC input/output port are respectively connected to a load group And a switch group, the switch group is further connected to a single-phase three-wire type a power distribution system; a filter capacitor group connected between the first end, the second end, and the third end of the AC input/output port; and a controller for controlling the bridge power converter Power electronic switches to achieve the desired function. The single-phase three-wire three-turn power conversion system according to claim 1, wherein the power electronic switch is selected from a semiconductor switch. The single-phase three-wire three-turn power conversion system according to claim 1, wherein the series connection of the two capacitors of the capacitor arm is connected to the AC input/output 埠 neutral line. According to the single-phase three-wire three-turn electric energy conversion system described in claim 1, wherein the decoupling loop is formed by connecting two capacitors in series, and the two ends of the two capacitors are respectively the first end of the decoupling loop And a second end point, and the series connection of the two capacitors is a third end point of the decoupling loop. The single-phase three-wire three-turn electric energy conversion system according to claim 1, wherein the high-voltage DC input/output voltage source is a power source, a solar cell array or a high-voltage DC bus bar converted by the electric energy converter. The single-phase three-wire three-turn power conversion system according to claim 1, wherein the low-voltage DC input/output voltage source can be a solar cell array, a fuel cell, a battery pack, or a low-voltage DC bus. According to the single-phase three-wire three-turn power conversion system described in claim 1, wherein the controller generates a control signal, so that the single-phase three-wire three-turn power converter performs load balancing and active mode when the utility power is normal. A power filter and a function of charging or discharging the low voltage DC input/output voltage source. According to the single-phase three-wire three-turn power conversion system described in claim 1, wherein the controller generates a control signal to enable the single-phase three-wire three-turn power converter to perform an uninterruptible power supply when the utility power is cut off. Provider function.