TW201414157A - Grid-connected photovoltaic generation system with positive grounding for solar cell arrays - Google Patents

Abstract

A grid-connected photovoltaic generation system includes a solar cell array, an energy buffer, a DC-DC converter set, a DC-AC converter and a controller. The solar cell array has an output port including a positive potential terminal and a negative potential terminal. The output port of the solar cell array connects with the energy buffer in parallel and further connects with an input port of the DC-DC converter set. An input port of the DC-AC converter connects with an output port of the DC-DC converter set and an output set of the DC-AC converter connects with a utility grid. The controller is operated to generate control signals to controllably switch power switches of the DC-DC converter set and the DC-AC converter. The positive potential terminal of the solar cell array connects to a ground terminal of the utility grid so as to perform directly grounding.

Description

Mains parallel solar power system with solar cell array positive potential terminal grounded

The invention relates to a mains parallel solar power generation system in which a positive potential end of a solar cell array is directly grounded; in particular, a non-isolated mains parallel solar power generation system in which a positive potential end of a solar cell array is directly grounded; The utility model relates to a commercial electric parallel solar power generation system suitable for directly grounding a positive potential end of a solar cell array composed of a thin film solar cell module (A-300) made of a monocrystalline material, which can avoid the thin film solar energy. Damage to the battery module due to polarization.

The utility model relates to a method for controlling a DC/DC electric energy converter of a DC voltage chopper suppression input device and a device thereof, as shown in FIG. Schematic diagram of the structure of the commercial parallel solar power generation system 1. Referring to FIG. 1 , the mains parallel solar power generation system 1 includes a DC input voltage source 11 , a DC-DC power converter 12 , an energy buffer 13 , and a DC-AC power converter 14 . The commercial parallel solar power generation system 1 is connected to an AC power distribution system 15. In the commercial parallel solar power generation system 1, the positive potential end of the DC input voltage source 11 cannot be directly connected to the ground end of the AC power distribution system 15, Thus, the thin film solar cell module [A-300] produced by the single crystal germanium material is polarized, which causes damage and life of the thin film solar cell, and causes leakage current to cause overall electric energy conversion efficiency. reduce.

Another conventional utility power parallel solar power generation system, as shown in Fig. 2, is a new patent of the solar photovoltaic power generation system of the Republic of China Patent Publication No. M408678, which discloses a schematic diagram of the structure of the solar photovoltaic power generation system 2. Referring to FIG. 2, the solar photovoltaic power generation system 2 includes a solar photovoltaic module 21 and a The active clamp circuit 22, a power converter 23 and an AC selection switch circuit 24. The solar photovoltaic power generation system 2 is connected to an AC power distribution system 25, in which the power converter 23 includes an isolation transformer, the primary side of which is two windings, and the isolation transformer is twice The side is a winding, so that the positive potential end of the solar photovoltaic module 21 can be directly connected to the ground end of the AC power distribution system 25. Although the solar photovoltaic power generation system 2 can solve the damage caused by the polarization phenomenon of the thin film solar cell module [A-300] manufactured by the single crystal germanium material, the use of the isolation transformer causes the overall power generation. The disadvantages of reduced system conversion efficiency and increased cost.

The above-mentioned patent applications of the Republic of China Patent Publication No. I356566 and No. M408678 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 non-isolated mains parallel solar power generation system in which a positive potential terminal of a solar cell array is grounded, which does not require an isolation transformer to improve power conversion efficiency, and since the solar cell array is positive. The potential end can be directly grounded, which can improve the damage caused by the polarization phenomenon of the thin film solar cell module [A-300] manufactured by the single crystal germanium material, and can reduce the leakage current.

The main object of the present invention is to provide a mains parallel solar power generation system with a positive potential end of a solar cell array, which does not need to use an isolation transformer to avoid the reduction of power generation conversion efficiency caused by the isolation transformer, so as to achieve the purpose of improving the power conversion efficiency.

Another object of the present invention is to provide a commercial parallel power solar power generation system in which a positive potential end of a solar cell array is grounded, wherein the solar cell module is made of a single crystal germanium material, and the positive potential end of the solar cell array is directly grounded, which can reduce the generation. Leakage current and avoid damage caused by polarization of the solar cell module. In order to achieve the purpose of extending the life of the solar cell module.

In order to achieve the above object, a commercial power parallel solar power generation system in which a positive potential terminal of a solar cell array is grounded according to a preferred embodiment of the present invention includes: a solar cell array in which a plurality of solar battery modules are connected in series or in parallel, the solar cell The array has an output 埠, the output 埠 includes a positive potential end and a negative potential end, the output 埠 outputs a direct current voltage and a direct current; an electric energy buffer is connected in parallel with the output 埠 of the solar cell array; a DC converter group having an input port and an output port, the input port of the DC-DC converter group being connected to the output port of the solar cell array; the DC-AC converter having an input port and an output埠, the input 埠 of the DC-AC converter is connected to the output 埠 of the DC-DC converter group; and a controller generates a control signal for separately controlling the DC-DC converter group and the DC Switching the power switch of the AC converter; wherein the output of the DC-AC converter is connected to an AC power distribution system, the It can be a positive electric potential side output port of an array of cells connected to a ground terminal of the AC power distribution systems, in order to form directly to ground.

The DC-DC converter set of the preferred embodiment of the present invention includes a DC-DC buck-boost converter and a DC-DC boost converter.

In the preferred embodiment of the present invention, the DC-DC buck-boost converter comprises an inductor, a power switch and a diode, and the DC-DC boost converter comprises an inductor, a power switch and a diode. body.

The DC-AC converter of the preferred embodiment of the present invention is selected from the group consisting of a half bridge DC-AC converter, a multi-stage half bridge DC-AC converter or a three-turn power converter.

In the preferred embodiment of the present invention, the three-turn power converter includes a capacitor arm, a first arm, a second arm, a filter inductor, a decoupling circuit, and an energy storage component.

The controller of the preferred embodiment of the present invention comprises a voltage outer loop control unit, a current inner loop control unit and a PWM circuit for controlling the DC-DC boost converter.

The controller of the preferred embodiment of the present invention comprises a voltage external loop control unit, a current inner loop control unit and a PWM circuit for controlling the DC-DC buck-boost converter.

In the preferred embodiment of the invention, the controller comprises a DC bus voltage control unit, a current control unit and a PWM circuit for controlling the half bridge DC-AC converter.

The controller of the preferred embodiment of the present invention comprises a DC bus voltage control unit, a current control unit, a first PWM circuit and a second PWM circuit for controlling a multi-stage half bridge DC-AC conversion Device.

The controller of the preferred embodiment of the present invention comprises an energy storage component voltage/current control unit, a DC bus voltage control unit, a current control unit, a first PWM circuit and a second PWM circuit for controlling A three-turn power converter.

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.

Referring to FIG. 3, the solar cell parallel-type solar power generation system 3 with the positive potential end of the solar cell array of the preferred embodiment of the present invention includes a solar cell array 31, an electric energy buffer 32, and a DC-DC converter group. 33. A DC-AC converter 34 and a controller 36. The solar cell parallel-type solar power generation system 3 with the positive potential end of the solar cell array is connected to an AC power distribution system In the system 35, the commercial power parallel solar power generation system 3 whose ground potential terminal is grounded generates an AC power to be injected into the AC power distribution system 35.

For example, the solar cell array 31 is composed of a plurality of solar cell modules connected in series and in parallel, and is a thin film solar cell module [A-300] manufactured by using single crystal germanium as a material. The solar cell array 31 has an output port for outputting a DC voltage and a DC current, and the output port of the solar cell array 31 includes a positive potential terminal G and a negative potential terminal A. The two terminals G and A of the output port of the solar cell array 31 are connected in parallel with the power buffer 32. In addition, the positive potential terminal G of the output 埠 of the solar cell array 31 directly forms a ground.

The DC-DC converter group 33 and the DC-AC converter 34 respectively have an input port and an output port, and the output terminals of the solar cell array 31 have two terminals G and A and the DC-DC converter group 33. The two endpoints G of the input port form a corresponding connection with A.

In addition, the three terminals B, G, and C of the output port of the DC-DC converter group 33 are connected to the three terminals B, G, and C of the input port of the DC-AC converter 34. As shown in FIG. 3, the points B and C of the DC-AC converter 34 are the voltage V _{BC of} the DC bus, and the voltage between the terminals B and G is V _BG and at the end G and The voltage between point C is V _GC , and the relationship of this voltage can be expressed as: V _BG =V _GC (1)

V _BG +V _GC =V _BC (2)

The two ends D, G of the output of the DC-AC converter 34 are connected to the two terminals D, G of the AC power distribution system 35, and the end point G of the output port of the AC power distribution system 35 is directly connected, so The positive potential terminal G of the output 埠 of the solar cell array 31 can be directly grounded. The controller 36 generates a control signal to control the switching of the power electronic switching elements of the DC-DC converter group 33 and the DC-AC converter 34.

The mains parallel solar power generation system 3 of the present invention is a non-isolated mains parallel solar power generation system in which the positive potential end of the solar cell array is grounded. The system does not use an isolation transformer, and the positive potential end of the solar cell array 31 is directly grounded. This not only reduces the energy loss caused by the isolation transformer and reduces the weight and volume of the power converter equipment, but also avoids the problem of damage caused by polarization caused by the special material thin film solar cell [A-300].

Referring again to FIG. 3, the DC-DC converter group 33 includes a DC-DC buck-boost converter 331 and a DC-DC boost converter 332. The DC-DC buck-boost converter 331 includes an inductor 3311, a power switch 3312, and a diode 3313. The DC-DC boost converter 332 includes an inductor 3321, a power switch 3322, and a diode. Body 3323. The DC-DC buck-boost converter 331 performs boosting of the output voltage of the solar cell array 31, and regulates V _BG to be one-half of the DC bus bar V _BC voltage, and the DC-DC boost converter 332 controls the solar energy. The output voltage of the battery array 31 performs maximum power tracking [MPPT] and boosts the voltage of the solar array 31 to supply a voltage V _GC . The power buffer 32 can suppress the high frequency chopping voltage generated by the DC-DC converter group 33 to avoid interfering with the DC-DC boost converter 332 performing the MPPT function.

Referring to Figures 3, 4A, 4B and 4C, the DC-AC converter 34 is selected from the group consisting of a half bridge DC-AC converter 341 and a multi-stage half bridge DC-AC converter (ie, a diode clamp). A multi-stage half-bridge DC-AC converter 342 and a three-turn power converter (ie, a three-turn power converter with a separate capacitor) 343. The DC-AC converter 34 performs a regulated DC bus voltage V _BC and its output current is a low harmonic distortion sine wave current that is in phase with the AC power distribution system 35 voltage. The controller 36 controls the power switch switching of the DC-DC converter group 33 and the DC-AC converter 34 respectively, so that the DC-DC converter group 33 and the DC-AC converter 34 can achieve MPPT and regulated DC convergence. The function of discharging voltage and generating sine wave current. As shown in FIG. 4C, the three-turn power converter 343 includes a capacitor arm 3431, a first arm 3432, a second arm 3343, a filter inductor 3434, a decoupling circuit 3435, and an energy storage component 3436.

The input port of the DC-DC converter group 33 is connected to the output port of the solar cell array 31. When the DC-AC converter 34 is injected into the AC power distribution system 35, the DC bus voltage V _BC is generated. The low-frequency chopping voltage of the mains voltage is twice as high. If the output voltage of the solar cell array 31 has a large chopping voltage, the power obtained by the DC-DC boost converter 332 to perform MPPT is lowered. Therefore, the DC-DC converter group 33 must suppress the chopping voltage of the DC bus bar from being transmitted to the output port of the solar cell array 31, so that the DC-DC boost converter 332 can perform MPPT to achieve maximum effect, so The DC-DC converter group 33 adopts dual-loop control, which includes control of a voltage outer loop and control of a current inner loop, and the current inner loop controls the inductor current to reach a near fixed current, blocking the chopping voltage of the DC bus. .

Referring to FIGS. 3, 4A, 4B and 4C, the DC-DC buck-boost converter 331 and the DC-DC boost converter 332 respectively supply DC power to the capacitor arm of the DC-AC converter 34. [Upper] capacitor 3411 and [down] capacitor 3412, DC bus voltage V _BC is the sum of capacitor voltage V _BG and V _GC . The DC-DC buck-boost converter 331 controls the capacitor voltage V _BG , and the DC bus voltage V _{BC is} controlled by the DC-AC converter 34, so if the voltage V _{BG of} the capacitor 3411 and the DC bus voltage V _BC Control is performed such that the voltage V _{GC of the} other capacitor 3412 is also controlled.

Referring to Figures 3 and 5A, it is disclosed that the controller 36 performs a block diagram of a control circuit 361 that controls the DC-DC buck-boost converter 331. The controller 36 has a control circuit 361 including a voltage outer loop control unit 3611, a current inner loop control unit 3612, and a PWM circuit 3613. The voltage outer loop control unit 3611 and the current inner loop control unit 3612 receive the voltage of the capacitor 3411 and the current of the inductor 3311, respectively, to generate the control signal. The voltage outer loop control unit 3611 includes a voltage detector 36111, an amplifier 36112, a subtractor 36113 and a P-I controller 36114, and the current inner loop control unit 3612 includes a current detector 36121, a subtractor 36122 and a current controller 36123.

The voltage detector 36111 is configured to detect the voltage V _{BG of} the capacitor 3411. The amplifier 36112 amplifies the DC bus set voltage by 0.5 times of a magnification to generate a DC bus set voltage of 0.5 times. The amplifier 36112 The output and the output of the voltage detector 36111 are supplied to the subtractor 36113 to obtain a voltage error signal of the capacitor 3411. The output of the subtractor 36113 is then sent to the PI controller 36114 to generate a reference signal for the current of the inductor 3311. The current detector 36121 is configured to detect the current of the inductor 3311, and send the reference signal output by the PI controller 36114 and the output of the current detector 36121 to the subtractor 36122, and output the error of the subtractor 36122. A signal is sent to the current controller 36123 to generate a control signal. Then, the output of the current controller 36123 is sent to the PWM circuit 3613 to generate a PWM signal to control the power electronic switching elements of the DC-DC buck-boost converter 331.

Referring to Figures 3 and 5B, it is disclosed that the controller 36 performs a block diagram of the control circuit 362 that controls the DC-DC boost converter 332. The controller 36 has a control circuit 362 including a voltage outer loop control unit 3621, a current inner loop control unit 3622, and a PWM circuit 3623. The voltage outer loop control unit 3621 and the current inner loop control unit 3622 respectively receive the output voltage of the solar cell array 31 and the current of the inductor 3321 to generate the control signal. The voltage outer loop control unit 3621 includes a voltage detector 36211, an MPPT controller 36212, a subtractor 36213 and a PI controller 36214, and the current inner loop control unit 3622 includes a current detector 36221, a subtraction method. The device 36222 and a current controller 36223.

The voltage detector 36211 is configured to detect the output voltage of the solar cell array 31. The current of the inductor 3321 is detected by the current detector 36221 and sent to the MPPT controller with the output of the voltage detector 36211. 36212 to determine the output voltage of the solar cell array 31. In addition, the MPPT control The output voltage of the controller 36212 and the output of the voltage detector 36211 are sent to the subtractor 36213 to obtain a voltage error signal. The output of the subtractor 36213 is sent to the PI controller 36214 to generate a reference signal of the inductor current, and the output of the PI controller 36214 and the output of the current detector 36221 are sent to the subtractor 36222. The output of the subtractor 36222 is sent to the current controller 36223 to generate a control signal. The output of the current controller 36223 is sent to the PWM circuit 3623 to generate a PWM signal to control the power electronic switching elements of the DC-DC boost converter 332.

Referring to Figures 3 and 6A, it is disclosed that the controller 36 performs a block diagram of the control circuit 363 that controls the half-bridge DC-AC converter 341. The controller 36 has a control circuit 363, which includes a DC bus voltage control unit 3631, a current control unit 3632, and a PWM circuit 3633. The current control unit 3632 is configured to control the half bridge DC-AC converter. 341 output current. The DC bus voltage control unit 3631 and the current control unit 3632 respectively receive the DC bus voltage V _BC , the voltage of the AC power distribution system 35, and the output current of the half bridge DC-AC converter 341 to generate the control signal. The DC bus voltage control unit 3631 includes a voltage detector 36311, a subtractor 36312 and a PI controller 36313. The current control unit 3632 includes a voltage detector 36321, a waveform generating circuit 36322, and a current check. The output 36323, a multiplier 36324, a subtractor 36325 and a current controller 36326.

The voltage detector 63511 is configured to detect the DC bus voltage V _BC , and the DC bus voltage V _BC is detected by the voltage detector 36311 and input to the DC bus set voltage to the subtractor 36312 to obtain a voltage. Error signal. The output of the subtractor 36312 is sent to the PI controller 36313 to obtain a DC bus voltage control signal.

The voltage of the AC power distribution system 35 is detected by the voltage detector 36321 and sent to the waveform generating circuit 36322 to generate a unit sine wave signal in phase with the voltage of the AC power distribution system 35. The waveform generation circuit 36322 is output again. The signal is multiplied by the output signal of the P-I controller 36713 to the multiplier 36324 to generate a half bridge DC-AC converter 341 output current reference signal. After the output current of the half bridge DC-AC converter 341 is detected by the current detector 36723, the current reference signal outputted from the multiplier 36324 is sent to the subtractor 36325 for subtraction. The output of the subtractor 36325 is sent to the current controller 36326, and the current controller 36326 is sent to the PWM circuit 3633 to generate a PWM signal to control the power electronic switching element of the half bridge DC-AC converter 341.

Referring to Figures 3 and 6B, it is disclosed that the controller 36 performs a block diagram of the control circuit 364 that controls the multi-stage half-bridge DC-AC converter 342. The controller 36 has a control circuit 364, which includes a DC bus voltage control unit 3641, a current control unit 3642, a first PWM circuit 3643, and a second PWM circuit 3644. The current control unit 3642 is used to control The output current of the multi-stage half-bridge DC-AC converter 342. The DC bus voltage control unit 3641 and the current control unit 3642 respectively receive the DC bus voltage V _BC , the voltage of the AC power distribution system 35 and the output current of the multi-stage half bridge DC-AC converter 342 to generate the control. signal. The DC bus voltage control unit 3641 includes a voltage detector 36411, a subtractor 36412 and a PI controller 36413. The current control unit 3642 includes a voltage detector 36421, a waveform generating circuit 36422, and a current check. The output unit 36423, a multiplier 36424, a subtractor 36425 and a current controller 36426.

The voltage detector 36411 is configured to detect the DC bus voltage V _BC , and the DC bus voltage V _BC is detected by the voltage detector 36411 and then input to the DC bus set voltage to the subtractor 36412 to Obtain a DC bus voltage error signal. The output voltage error signal of the subtractor 36412 is sent to the PI controller 36413 to obtain a DC bus voltage control signal. The voltage of the AC power distribution system 35 is detected by the voltage detector 36621 and sent to the waveform generating circuit 36622 to generate a unit sine wave signal in phase with the voltage of the AC power distribution system 35. The waveform generating circuit 36422 outputs a unit sine wave signal and the output of the PI controller 36413 is supplied to the multiplier 36424 to obtain a reference output current signal. After the output current of the multi-stage half-bridge DC-AC converter 364 is detected by the current detector 36423, the reference output current signal outputted by the multiplier 36424 is sent to the subtractor 36425 for subtraction. The output of the subtractor 36425 is sent to the current controller 36426, the output of the current controller 36426 is sent to the first PWM circuit 3643, and the output of the current controller 36426 is sent to the second PWM circuit 3644. The first PWM circuit 3643 and the second PWM circuit 3644 respectively generate PWM signals to control the power electronic switching elements of the multi-stage half-bridge DC-AC converter 342. The carrier signals of the first PWM circuit 3643 and the second PWM circuit 3644 are respectively an upper triangular carrier signal and a lower triangular carrier signal.

Referring to Figures 3 and 6C, it is disclosed that the controller 36 performs a block diagram of the control circuit 365 that controls the three-turn power converter 343. The controller 36 has a control circuit 365, which includes an energy storage component voltage/current control unit 3651, a DC bus voltage control unit 3652, a current control unit 3653, a first PWM circuit 3654 and a second PWM circuit. 3655, wherein the current control unit 3653 controls an output current of the three-turn power converter 343. The energy storage component voltage/current control unit 3651 detects the output voltage and current of the energy storage component, and the DC bus voltage control unit 3652 detects the voltage of the AC power distribution system 35 and the DC bus voltage V _BC . The current control unit 3653 detects the output current of the first arm 3432 and the output current of the second arm 3433 to generate the control signal. The energy storage device voltage/current control unit 3651 includes a current detector 36511, a subtractor 36512, a voltage detector 36513, a subtractor 36514, a selection switch 36515, a PI controller 36616, and an inverting amplifier. 36517. The DC bus voltage control unit 3652 includes a voltage detector 36521, a waveform generating circuit 36522, a voltage detector 36523, a subtractor 36524, a PI controller 36525, and a multiplier 36526. The current control unit 3653 includes a current detector 36531, an amplifier 36533, an adder 36534, an adder 36535, a subtractor 36536, a subtractor 36537, a first current controller 36538 and a second current control.器36539.

The current detector 36511 is configured to detect an output current of the energy storage component, and send the output of the current detector 36511 and the energy storage component output set current to the subtractor 36512 to obtain a current error signal. The voltage detector 36513 is configured to detect the output voltage of the energy storage component, and send the output of the voltage detector 36513 and the energy storage component output set voltage to the subtractor 36514 to obtain a voltage error signal. The output of the subtractor 36512 and the subtractor 36514 is sent to the selection switch 36515, and the selection switch 36515 is executed according to the current control mode, and may perform a constant voltage or a constant current charging on the energy storage element, or may perform the pair The energy storage element performs a discharge. When the selection switch 36515 selects the error current signal, the constant current charging or the constant current discharging may be performed; or when the selection switch 36515 selects the error voltage signal, the constant voltage charging may be performed. The output of the selection switch 36515 is sent to the PI controller 36616, and the output of the PI controller 36616 is sent to the inverting amplifier 36517, so that the energy storage component is obtained from the output of the PI controller 36616 and the inverting amplifier 36517. Voltage or current control signal.

The voltage detector 36523 detects that the DC bus voltage V _BC and the DC bus set voltage are sent to the subtractor 36624 for subtraction to obtain an error signal. The output error signal of the subtractor 36624 is sent to the PI controller 36525, and the voltage detector 35521 detects the voltage of the AC power distribution system 35 and sends it to the waveform generating circuit 36522 to generate the AC power distribution system. 35 unit sine wave signal with the same phase of voltage. The output of the waveform generating circuit 36522 and the PI controller 36525 is sent to the multiplier 36526 to obtain a DC bus voltage control signal.

The output of the multiplier 36526 is sent to the 0.5x amplifier 36533. The output of the amplifier 36533 and the P-I controller 36516 is sent to the adder 36534. The current detector 36531 detects the output current of the first arm 3432, and sends the output of the current detector 36531 and the adder 36534 to the subtractor. 36536, the output of the subtractor 36536 is sent to the first current controller 36538, and the output of the first current controller 36538 is sent to the first PWM circuit 3654 to generate a PWM signal to control the first Power electronic switching element of arm 3432. The output of the amplifier 36533 and the inverting amplifier 36517 is sent to the adder 36535, and the output current of the second arm 3433 is detected by the current detector 36532, and the output of the current detector 36532 and the adder 36535 is sent. Up to the subtractor 36537, the output of the subtractor 36537 is sent to the second current controller 36539, and the output of the second current controller 36539 is sent to the second PWM circuit 3655 to generate a PWM signal. The power electronic switching element of the second arm 3433 is controlled.

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‧‧‧Commercial parallel solar power system

11‧‧‧DC input voltage source

12‧‧‧DC-DC Energy Converter

13‧‧‧Electric energy buffer

14‧‧‧DC-AC Energy Converter

15‧‧‧AC power distribution system

2‧‧‧Solar Photovoltaic Power System

21‧‧‧Solar Photovoltaic Module

22‧‧‧Active Clamp Circuit

23‧‧‧Power Converter

24‧‧‧AC selection switch circuit

25‧‧‧AC power distribution system

3‧‧‧Commercial parallel solar power system

31‧‧‧Solar battery array

32‧‧‧Electric energy buffer

33‧‧‧DC-DC converter group

331‧‧‧DC-DC buck-boost converter

3311‧‧‧Inductors

3312‧‧‧Power switch

3313‧‧‧ diode

332‧‧‧DC-DC Boost Converter

3321‧‧‧Inductors

3322‧‧‧Power switch

3323‧‧ ‧ diode

34‧‧‧DC-AC Converter

341‧‧‧Half-bridge DC-AC converter

3411‧‧‧ capacitor

3412‧‧‧ capacitor

342‧‧‧Multi-step half-bridge DC-AC converter

343‧‧‧Three-pole power converter

3431‧‧‧Capacitor arm

3432‧‧‧First arm

3433‧‧‧second arm

3434‧‧‧Filter inductor

3435‧‧‧Decoupling circuit

3436‧‧‧ Energy storage components

35‧‧‧AC power distribution system

36‧‧‧ Controller

361‧‧‧Control circuit

3611‧‧‧Voltage outer loop control unit

36111‧‧‧Voltage detector

36112‧‧‧Amplifier

36113‧‧‧Subtractor

36114‧‧‧P-I controller

3612‧‧‧current inner loop control unit

36121‧‧‧ Current detector

36122‧‧‧Subtractor

36123‧‧‧ Current controller

3613‧‧‧PWM circuit

362‧‧‧Control circuit

3621‧‧‧Voltage outer loop control unit

36211‧‧‧Voltage detector

36212‧‧‧MPPT controller

36213‧‧‧Subtractor

36214‧‧‧P-I controller

3622‧‧‧current inner loop control unit

36221‧‧‧ Current detector

36222‧‧‧Subtractor

36223‧‧‧ Current controller

3623‧‧‧PWM circuit

363‧‧‧Control circuit

3631‧‧‧DC bus voltage control unit

36311‧‧‧Voltage detector

36312‧‧‧Subtractor

36313‧‧‧P-I Controller

3632‧‧‧ Current Control Unit

36321‧‧‧Voltage detector

36322‧‧‧ Waveform generating circuit

36323‧‧‧ Current detector

36324‧‧‧Multiplier

36325‧‧‧Subtractor

36326‧‧‧ Current controller

3633‧‧‧PWM circuit

364‧‧‧Control circuit

3641‧‧‧DC bus voltage control unit

36411‧‧‧Voltage detector

36412‧‧‧Subtractor

36413‧‧‧P-I controller

3642‧‧‧ Current Control Unit

36421‧‧‧Voltage detector

36422‧‧‧ Waveform generating circuit

36423‧‧‧ Current detector

36424‧‧‧Multiplier

36425‧‧‧Subtractor

36426‧‧‧ Current controller

3643‧‧‧First PWM circuit

3644‧‧‧Second PWM circuit

365‧‧‧Control circuit

3651‧‧‧ Energy storage component voltage / current control unit

36511‧‧‧current detector

36512‧‧‧Subtractor

36513‧‧‧Voltage detector

36514‧‧‧Subtractor

36515‧‧‧Selection switch

36516‧‧‧P-I controller

36517‧‧‧Inverting amplifier

3652‧‧‧DC bus voltage control unit

36521‧‧‧Voltage detector

36522‧‧‧ Waveform generating circuit

36523‧‧‧Voltage detector

36524‧‧‧Subtractor

36525‧‧‧P-I controller

36526‧‧‧Multiplier

3653‧‧‧ Current Control Unit

36531‧‧‧ Current detector

36532‧‧‧ Current detector

36533‧‧‧Amplifier

36534‧‧‧Adder

36535‧‧‧Adder

36536‧‧‧Subtractor

36537‧‧‧Subtractor

36538‧‧‧First current controller

36539‧‧‧Second current controller

3654‧‧‧First PWM circuit

3655‧‧‧Second PWM circuit

Figure 1: Schematic diagram of the structure of a commercial parallel power solar power system of the Republic of China Patent No. I356566.

Figure 2: Schematic diagram of the structure of the solar photovoltaic power generation system of the Republic of China Patent No. M408678.

Fig. 3 is a schematic view showing the structure of a commercial parallel solar power generation system according to a preferred embodiment of the present invention.

4A is a schematic view showing the architecture of a half-bridge DC-AC converter in a commercial parallel solar power generation system according to a preferred embodiment of the present invention.

FIG. 4B is a schematic diagram showing the architecture of a multi-stage half-bridge DC-AC converter in a commercial parallel solar power generation system according to a preferred embodiment of the present invention.

FIG. 4C is a schematic diagram showing the architecture of a three-turn power converter in a commercial parallel solar power generation system according to a preferred embodiment of the present invention.

Fig. 5A is a block diagram showing a controller for controlling a DC-DC buck-boost converter of a commercial power parallel solar power generation system according to a preferred embodiment of the present invention.

FIG. 5B is a block diagram of a controller for controlling a DC-DC boost converter in a commercial parallel solar power generation system according to a preferred embodiment of the present invention.

Fig. 6A is a block diagram of a controller of a half-bridge DC-AC converter using a commercial parallel power solar power generation system according to a preferred embodiment of the present invention.

FIG. 6B is a block diagram of a controller of a multi-stage half-bridge DC-AC converter using a commercial parallel power solar power generation system according to a preferred embodiment of the present invention.

Figure 6C is a block diagram of a controller for a commercial parallel power solar power system in accordance with a preferred embodiment of the present invention using a three-turn power converter.

3‧‧‧Commercial parallel solar power system

31‧‧‧Solar battery array

32‧‧‧Electric energy buffer

33‧‧‧DC-DC converter group

331‧‧‧DC-DC buck-boost converter

3311‧‧‧Inductors

3312‧‧‧Power switch

3313‧‧‧ diode

332‧‧‧DC-DC Boost Converter

3321‧‧‧Inductors

3322‧‧‧Power switch

3323‧‧ ‧ diode

34‧‧‧DC-AC Converter

35‧‧‧AC power distribution system

36‧‧‧ Controller

Claims (10)

A solar cell parallel solar power generation system with a positive potential terminal grounded by a solar cell array, comprising: a solar cell array formed by connecting a plurality of solar cell modules in series or in parallel, the solar cell array having an output port, the output port Having a positive potential terminal and a negative potential terminal, the output of the current voltage and the current; a power buffer connected in parallel with the output 埠 of the solar cell array; the DC-DC converter group having an input 埠And an output port, the input port of the DC-DC converter group is connected to the output port of the solar cell array; the DC-AC converter has an input port and an output port, and the input of the DC-AC converter Connected to an output port of the DC-DC converter group; and a controller that generates a control signal for separately controlling switching of the power switch of the DC-DC converter group and the DC-AC converter; The output of the DC-AC converter is connected to an AC power distribution system, and the output of the solar cell array is directly at the positive potential end To the ground terminal of the AC power distribution systems, in order to form directly to ground. The utility model relates to a mains parallel solar power generation system according to claim 1, wherein the DC-DC converter group comprises a DC-DC buck-boost converter and a DC-DC boost converter. According to the utility model as claimed in claim 2, the DC-DC buck-boost converter comprises an inductor, a power switch and a diode, and the DC-DC boost converter comprises An inductor, a power switch and a diode. The utility model relates to a commercial parallel solar power generation system according to claim 1, wherein the DC-AC converter is selected from the group consisting of a half bridge DC-AC converter, a multi-stage half bridge DC-AC converter or a three-inch converter. Energy converter. The utility model relates to a commercial parallel solar power generation system according to claim 4, wherein the three-turn power converter comprises a capacitor arm, a first arm, a second arm, a filter inductor, a decoupling circuit and a Energy storage component. The utility model relates to a commercial parallel solar power generation system according to claim 1, wherein the controller comprises a voltage outer loop control unit, a current inner loop control unit and a PWM circuit for controlling the DC-DC boost. converter. The utility model relates to a commercial parallel solar power generation system according to claim 1, wherein the controller comprises a voltage outer loop control unit, a current inner loop control unit and a PWM circuit for controlling the DC-DC buck-boost converter. The utility model relates to a commercial parallel solar power generation system according to claim 1, wherein the controller comprises a DC bus voltage control unit, a current control unit and a PWM circuit for controlling half bridge DC-AC conversion. Device. The utility model relates to a commercial power parallel solar power generation system according to claim 1, wherein the controller comprises a DC bus voltage control unit, a current control unit, a first PWM circuit and a second PWM circuit. Control a multi-stage half-bridge DC-AC converter. The utility model relates to a commercial power parallel solar power generation system according to claim 1, wherein the controller comprises an energy storage component voltage/current control unit, a DC bus voltage control unit, a current control unit, and a first PWM circuit. And a second PWM circuit for controlling a three-turn power converter.