TWI625020B - Hybrid solar conversion system - Google Patents

Abstract

The present invention provides a hybrid solar energy conversion system comprising: a first direct current conversion circuit; a second direct current conversion circuit; a transformer circuit; a third direct current conversion circuit; a direct current alternating current conversion circuit; a battery; and a control circuit performing the following steps: detecting the utility grid connection mode, feeding back the energy of the solar panel to the mains; detecting the non-commercial grid connection mode, feeding back the energy of the solar panel to the load; and judging the utility In the battery charging mode, the utility power is supplied to the battery for charging. Through the implementation of the present invention, the effects of improving system power generation efficiency, simplifying the circuit architecture, and reducing system circuit cost can be achieved.

Description

Hybrid solar energy conversion system

The invention relates to a hybrid solar energy conversion system, in particular to a hybrid solar energy conversion system for power conversion and management between solar panels, mains and loads.

As shown in Fig. 1, a conventional solar energy conversion system, a conventional solar energy conversion system, uses four sets of DC/DC power converters, two sets of transformers and rectifier circuits, and two sets of DC/AC power converters. , a set of AC / DC power converters, a DSP control circuit and other components. From the performance analysis of various operations, when the grid is connected to the grid and the battery is charged: a. The grid connection is η1xη2xη3, b. The battery charge is η7; 2. The non-mains grid connection and battery charging: a. The net is η4xη5xη6, b. the battery charge is η7; 3. the non-commercial grid and battery discharge: η4xη5xη6xη7. The conventional solar energy conversion system exists: a. The circuit system architecture is huge, b. The cost is high, c. The system integration compatibility is considered, d. The system conversion efficiency is low, and e. The utility power is not efficient for the battery charger converter. …And other issues.

As shown in Fig. 2, it is a conventional solar energy conversion system. The conventional solar energy conversion system 2 uses three sets of DC/DC power converters, two sets of transformers, a set of rectifier circuits, and a set of DC/AC power supplies. Converter, a set of AC/DC power converters, a DSP control circuit and other components. From the performance analysis of various operations, when the grid is connected to the grid and the battery is charged: a. The grid connection is η1xη2xη3, b. The battery charge is η1xη2xη4xη5; 2. Non-mains grid connection and battery charging: a. Non-commercial grid is η1xη2xη3, b. Battery charging is η1xη2xη4xη5; 3. Non-commercial grid connection and battery discharge: a. Non-commercial grid is η1xη2xη3, battery discharge is η4xη5. The conventional solar energy conversion system 2 exists: a. the high cost of the application converter on the battery side and the low efficiency of the converter, b. the non-grid type is applied to the back end load transient response is not good, and c. the mains to the battery charger The converter is not efficient...etc.

The invention relates to a hybrid solar energy conversion system, which mainly solves the problem of power conversion and management efficiency of solar panels.

The present invention provides a hybrid solar energy conversion system, comprising: a first DC conversion circuit for inputting a solar panel voltage; and a second DC conversion circuit electrically connected to an output end of the first DC conversion circuit; a transformer circuit electrically connected to the output end of the second DC conversion circuit; a third DC conversion circuit electrically connected to the output end of the transformer circuit; a DC current conversion circuit electrically connected to the third DC conversion An output end of the circuit; a switch, electrically connected to the output end of the DC-AC conversion circuit and a mains terminal and the load end; a battery electrically connected between the first DC conversion circuit and the second DC conversion circuit; And a control circuit electrically connected to the first DC conversion circuit, the third DC conversion circuit, the circuit and the switch, and the control circuit performs the following steps: determining the utility grid connection mode, when the utility voltage and the input solar panel voltage, When both voltages exist at the same time, the control circuit transmits a first signal to the switch, and the DC-AC conversion circuit is connected with the mains and The energy of the solar panel is fed back to the mains; the non-commercial grid-connected mode is determined. When the mains voltage does not exist, the control circuit transmits a second signal to the switch to connect the DC-AC conversion circuit with a load and The energy of the solar panel is fed back to the load; and the mains charging mode is determined. When the solar panel has no energy to supply to the battery, the control circuit transmits the first control signal to the switch. The DC-AC conversion circuit is connected to the mains, and the control circuit controls the DC-AC conversion circuit and the second DC conversion circuit to supply the utility energy to the battery for charging.

With the implementation of the present invention, at least the following advancements can be achieved:

First, the circuit cost and volume can be greatly reduced.

Second, it can improve the power generation efficiency of the circuit system.

3. The device can be moved more conveniently after the volume is reduced.

100‧‧‧Hybrid Solar Conversion System

10‧‧‧First DC conversion circuit

20‧‧‧Second DC conversion circuit

30‧‧‧Transformer circuit

40‧‧‧ Third DC conversion circuit

50‧‧‧DC AC conversion circuit

60‧‧‧Toggle switch

70‧‧‧Battery

71‧‧‧Additional battery

80‧‧‧Control circuit

91‧‧‧ solar panels

92‧‧‧Power

93‧‧‧load

94‧‧‧fourth DC conversion circuit

95‧‧‧Auxiliary power

[Fig. 1] is a conventional solar energy conversion system 1; [Fig. 2] is a conventional solar energy conversion system 2; [Fig. 3A] is a circuit block diagram of an embodiment of a hybrid solar energy conversion system of the present invention; 3B is a diagram of an embodiment of a control circuit control flow of the present invention; [Fig. 4] is a diagram of an embodiment of a commercial grid-connected mode of the hybrid solar energy conversion system of the present invention; [Fig. 5] is a hybrid solar energy conversion of the present invention. Embodiment diagram of a non-commercial grid-connected mode of the system; [FIG. 6] is a diagram of an embodiment of a utility-to-battery charging mode of the hybrid solar energy conversion system of the present invention;

As shown in FIG. 3A, the present embodiment is a hybrid solar energy conversion system 100, including: a first DC conversion circuit 10; a second DC conversion circuit 20; The circuit 30; a third DC conversion circuit 40; a DC current conversion circuit 50; a switch 60; a battery 70; and a control circuit 80.

The first DC conversion circuit 10 is configured to input a solar panel voltage of a solar panel 91. The first DC conversion circuit 10 can be a solar charge controller (PV Charger; Photovoltaic Charger).

The second DC conversion circuit 20 is electrically connected to the output end of the first DC conversion circuit 10; the second DC conversion circuit 20 is a Maximum Power Point Tracking Controller (MPPT Controller), and the MPPT controller can The power generation voltage of the solar panel 91 is instantly detected, and the highest voltage current value (VI) is tracked, so that the system charges the battery 70 with the maximum power output. The MPPT controller is used in a solar photovoltaic system to coordinate the work of the solar cell 70 board, the battery 70, and the load 93.

The transformer circuit 30 is electrically connected to the output end of the second DC conversion circuit 20, and mainly performs a boosting operation to boost the voltage output from the solar panel 91 to match the subsequent mains 92 or the load 93.

The third DC conversion circuit 40 is electrically connected to the output end of the transformer circuit 30 to enable the voltage output from the transformer circuit 30 to obtain more precise adjustment and a more stable output.

The DC-to-AC conversion circuit 50 is electrically connected to the output end of the third DC conversion circuit 40 for converting the DC voltage outputted by the third DC conversion circuit 40 into an AC voltage for grid connection with the utility power 92 or for use by the load 93. .

The switch 60 is electrically connected to the output end of the DC-AC conversion circuit 50 and a mains 92 end and a load 93 end. The change-over switch 60 is mainly used for switching the power supply, and the power output from the solar panel 91 is switched to be a commercial power supply. 92 is connected to the grid or used for load 93.

The battery 70 is electrically connected between the first DC conversion circuit 10 and the second DC conversion circuit 20 for adjusting the output power of the solar panel 91.

As shown in FIGS. 3A and 3B, the control circuit 80 can be a digital signal processing (DSP), and the control circuit 80 is telecommunicationly connected to the first DC conversion circuit 10, the third DC conversion circuit 40, and the circuit. And the switch 60, the control circuit 80 performs the following steps:

Determining the mains grid-connected mode, the control circuit 80 detects whether the mains voltage and the input solar panel 91 voltage are present. When the two voltages exist simultaneously, the control circuit 80 determines that the power converter is operating in the mains grid-connected mode. The control circuit 80 transmits a first control signal to a switch 60, and the first contact of the switch 60 is connected to the second contact, and the power output from the DC/DC converter circuit 50 is connected to the utility 92 and the solar panel is connected. The energy of 91 is fed back to the mains 92.

Determining the non-mains grid-connected mode, the control circuit 80 detects whether the mains voltage and the input solar panel voltage are present. When the mains voltage does not exist, the control circuit 80 determines that the power converter is operating in the non-mains grid-connected mode. The control circuit 80 transmits a second control signal to the switch 60, and the output of the DC-AC conversion circuit 50 is coupled to the load 93 by the connection of the second contact and the third contact of the switch 60, and the solar panel 91 is connected. The energy is fed back to the load 93.

Judging the mains charging mode: detecting that when the solar panel 91 has no energy to be supplied to the battery 70, the control circuit 80 sends a first control signal to the switching switch 60 to be connected to the mains 92, and the control circuit 80 controls the DC alternating current converting circuit 50 and the The two DC conversion circuit 20 operates to supply the mains 92 energy to the battery 70 for charging.

The hybrid solar energy conversion system 100 of the present embodiment may further include a fourth DC conversion circuit 94, which is a battery charger, and the fourth DC conversion circuit 94 is electrically connected to the system. The built-in battery 70 is electrically connected to the external battery 71, whereby the energy of the built-in battery 70 of the system can be expanded.

The hybrid solar energy conversion system 100 of the present embodiment may further have an auxiliary power source 95 electrically connected to the input end of the first DC conversion circuit 10 or the output end of the battery 70. The auxiliary power 95 may be provided by a For example, the connection terminal of the USB (Universal Serial Bus) is connected to the outside, whereby the diversity of the hybrid solar energy conversion system 100 can be increased.

As shown in Fig. 4, the operation of the mains grid-connected mode is as follows: When the voltage of the solar panel 91 is higher than the system starting voltage setting value, the system power supply starts to operate and wakes up the control circuit 80. After the control circuit 80 is started, it will detect the output power voltage of the system, that is, the output voltage of the DC-AC conversion circuit 50 and the input voltage of the solar panel, that is, the input voltage of the first DC conversion circuit 10, whether both exist at the same time. And to determine whether the voltage value is operated under the set conditions, the relevant setting conditions are the conditions of the flow operation that need to be satisfied under the general inverter specification requirements.

When the condition is met, the control circuit 80 will judge that the system operates in the grid connection mode of the utility power 92. At this time, the control circuit 80 will send a control signal to the first DC conversion circuit 10 for DC/DC conversion operation, which will be solar energy. Energy is provided for use by battery 70. Since the solar energy is very low in the morning or at dusk, the basic energy load test will be performed first. When the conditions are set by the test, the inverter will enter the normal operating condition, and when the solar panel 91 provides enough energy to supply the battery 70, The control circuit 80 will control the second DC conversion circuit 20 to convert the energy of the battery 70 to Vbus and raise the Vbus voltage above the mains 92 peak voltage.

When this condition is satisfied, the first signal is sent to the changeover switch 60, and the first end point and the second end point of the changeover switch 60 are connected, and then the mains 92 is connected to prevent the utility power 92 surge current from being generated. Battery 70 and excess energy will also be passed through DC by second DC conversion circuit 20 The stream conversion circuit 50 is supplied to the commercial power source 92 and has reached the power saving function. In addition, from the performance analysis of the grid connection operation of the mains 92, the grid connection and the battery 70 are charged in the mains 92: a. the grid 92 is η2xη3xη4, b. the battery 70 is charged η1.

As shown in FIG. 5, the operation of the non-mains grid-connected mode indicates that when the solar panel voltage is higher than the system starting voltage set value, the system power supply starts to operate and wakes up the control circuit 80. After the control circuit 80 is started, it will detect whether the system output mains voltage and the solar panel input voltage are present and the voltage value is operated under the set condition. When the output no mains voltage exists, the control circuit 80 will judge that the system operates in the non-commercial power 92. Grid mode.

When operating in this mode, the control circuit 80 will provide a second signal to the switch 60, connect the second point of the switch 60 to the third point and detect the presence of the battery 70. When the battery 70 is present, the first A DC conversion circuit 10 operates to transfer the energy of the solar panel 91 to the battery 70 to charge the battery 70, while the second DC conversion circuit 20 also supplies energy to the Vbus, and converts the DC voltage into an AC power by the DC AC conversion circuit 50. Provided to the back end AC load 93 for use. In addition, from the performance analysis of non-mains 92 grid-connected operation, the non-commercial power grid 92 and battery 70 are charged: a. non-commercial power grid 92 is η2xη3xη4, b. battery 70 is charged η1; The discharge of the battery 70 is η2xη3xη4.

As shown in FIG. 6, the operation description of the mains charging mode: when the solar panel 91 has no energy to be supplied to the battery 70, the control circuit 80 will detect the solar panel input voltage, the battery voltage and the mains voltage, when the setting conditions are met. The control circuit 80 sends a signal to the second DC conversion circuit 20 to raise the Vbus voltage to above the peak voltage of the mains 92, and the control circuit 80 sends the first signal to the switch 60 to switch the first point of the switch 60 and The second point is connected to connect the mains 92. Further, the control circuit 80 determines that the commercial power 92 is connected and the respective setting values are within the normal range, and controls the DC-to-AC conversion circuit 50 and the second DC conversion circuit 20 to supply the commercial power 92 to the battery 70 for charging.

Referring to FIG. 1 to FIG. 6 , in combination with the above, the conventional solar energy conversion system of the prior art (hereinafter referred to as the conventional one) and the conventional solar energy conversion system 2 (hereinafter referred to as the second) For comparison, the following is explained in the table:

Comparison of the number of system topologies:

Comparison of operational effectiveness: It can be clearly seen from the above comparison that the present embodiment has significant progress and improvement in efficacy over the prior art.

However, the above embodiments are intended to illustrate the features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and to implement it, and not to limit the scope of the patent of the present invention. All other equivalent modifications or modifications made without departing from the spirit of the present invention should be included in the scope of the claims described below.

Claims (5)

A hybrid solar energy conversion system, comprising: a first DC conversion circuit for inputting a solar panel voltage; a second DC conversion circuit electrically connected to an output end of the first DC conversion circuit; a voltage circuit electrically connected to the output end of the second DC conversion circuit; a third DC conversion circuit electrically connected to the output end of the transformer circuit; a DC AC conversion circuit electrically connected to the third DC An output end of the conversion circuit; a switch electrically connected to the output end of the DC-AC conversion circuit and a mains terminal and a load end; a battery electrically connected to the first DC conversion circuit and the second DC conversion And a control circuit electrically connected to the first DC conversion circuit, the third DC conversion circuit, the circuit and the switch, the control circuit performing the following steps: determining a grid connection mode of the utility When the mains voltage and the input solar panel voltage and the two voltages exist simultaneously, the control circuit transmits a first signal to the switch, and a DC-to-AC conversion circuit is coupled to the utility power and feeds back energy of the solar panel to the utility power; determining a non-mains grid-connected mode, when the utility voltage does not exist, the control circuit transmits a second signal to the Switching the switch, connecting the DC-to-AC conversion circuit to a load and feeding back energy of the solar panel to the load; and determining a mains charging mode, when the solar panel has no energy to supply the battery, the control circuit transmits the first The control signal is applied to the switch, the DC-to-AC conversion circuit is coupled to the mains, and the control circuit controls the DC-to-AC conversion circuit and the second DC conversion circuit to operate, and the utility energy is supplied to the battery for charging. The hybrid solar energy conversion system of claim 1, wherein the first direct current conversion circuit is a solar battery charging controller. The hybrid solar energy conversion system of claim 1, wherein the second DC conversion circuit is a maximum power point tracking controller. The hybrid solar energy conversion system of claim 1, further comprising a fourth DC conversion circuit electrically connected to the battery and electrically connected to the external battery. The hybrid solar energy conversion system of claim 1, further comprising an auxiliary power electrically connected to an input end of the first direct current conversion circuit or an output end of the battery.