KR101186182B1 - Pwm controller and control method for wind power or solar generation - Google Patents

Abstract

PURPOSE: A PWM controller and a controlling method thereof are provided to increase generation efficiency by protecting a generator with a braking operation in an overvoltage in wind and solar power generating processes. CONSTITUTION: A brake circuit part(10) processes a brake operation to decelerate a blade of a wind power generator. A booster circuit part raises a voltage by charging a condenser if a generation voltage is a low voltage. A controller charges the condenser by PWM-controlling a power semiconductor switching device. [Reference numerals] (AA) Dummy loader

Description

PWM controller in wind or photovoltaic power generation and control method {PWM CONTROLLER AND CONTROL METHOD FOR WIND POWER OR SOLAR GENERATION}

The present invention relates to a control technology of a wind or photovoltaic generator, and more particularly, in wind or photovoltaic power generation that can increase power generation efficiency by breaking operation during overvoltage and booster operation during low voltage in wind or solar power generation. The present invention relates to a PWM controller and a control method thereof.

Recently, environmental pollution, depletion of fossil energy, and stability of nuclear power generation have emerged as global issues. As an alternative, renewable energy such as solar, hydro, and wind power has emerged as a future growth industry. Active research and investment are being made together. In general, power generated from renewable energy is more efficient to operate in conjunction with a power system than a single operation, and is stable from a customer's point of view, so grid linkage technology of renewable energy is essential. In order to efficiently link the power generated from renewable energy to the grid, grid linkage technologies such as grid power supply, synchronous control, minimization of harmonics, and power factor control, high efficiency topology, stable voltage / frequency control, single operation prevention, and high reliability And inverter technology such as lower cost.

Techniques related to a conventional grid-connected inverter include a "grid-connected inverter device disclosed in Publication No. 10-2011-0054052, and a" grid-connected inverter "published in Publication No. 10-2011-0079749. The inverter is arranged on the output side of the inverter, the first capacitor pair consisting of an inverter for pulse width modulating the output of the DC power supply, two capacitors disposed on the input side of the inverter and connected in series to form a neutral point, and formed on the output side of the inverter. The second capacitor pair consisting of two capacitors connected in series to each other, a bypass path for leakage current formed by connecting the neutral point of the first capacitor pair and the neutral point of the second capacitor pair, and the first capacitor pair and the second capacitor pair Sine at least one common mode choke coil disposed between and suppressing the common mode current generated by the inverter, and a pulse width modulated voltage output from the inverter. An output filter which converts into a wave shape is provided.

In the conventional system-linked inverter, there is a problem in that a failure occurs due to excessive operation of the power generation device or the power generation power cannot be efficiently used because the power generation voltage of the solar generator or the wind generator is not sufficiently responded to.

The present invention has been proposed to solve the above problems, an object of the present invention in the wind or photovoltaic power generation that can increase the power generation efficiency by the braking operation during overvoltage and booster operation during low voltage in wind or solar power generation PWM controller and its control method to provide.

In order to achieve the above object, the circuit of the present invention receives electricity from a wind generator or a solar generator, and performs PWM control of an Insulated Gate Bipolar Transistor (IGBT) under the control of a controller to alternating DC power. PWM controller in wind power or photovoltaic power generation that converts power to the system and receives power generation voltage of solar power generator or solar panel voltage of solar power generator and transfers it to inverter. A brake circuit unit configured to process a brake operation to smoothly decelerate the blade of the wind generator by connecting the overvoltage of the wind generator to the dummy loader according to the PWM control of the controller when the voltage rises to the over voltage; A booster circuit unit configured to increase the voltage by charging the capacitor under the control of the controller when the generated voltage of the wind generator or the solar generator is low voltage; And monitoring the generated voltage of the wind generator and the solar panel voltage of the photovoltaic generator and switching the power semiconductor connected between the dummy loader and the neutral line with a PWM pulse proportional to the generated voltage when the generated voltage of the wind generator rises to overvoltage due to overheating. The device is controlled, and when the power generation voltage of the wind generator or the solar generator is a low voltage, PWM control the power semiconductor switching device connected to the first reactor, characterized in that configured as a controller for charging the charging capacitor.

The brake circuit unit includes a dummy loader connected between the T1 terminal and the T2 terminal, a first diode D1 receiving the generated voltage of the wind generator as the T3 terminal and transmitting the generated voltage in one direction to the T4 terminal. The second diode D2 that receives the input and transmits in one direction, the capacitor C1 connected between the first diode D1 and the second diode D2 and the T5 neutral terminal N, and the G1 / E1 PWM of the controller. The first IGBT (Q1) for connecting or disconnecting the dummy loader to the neutral terminal (N) according to the control signal, and the third diode (D3) connected in parallel between the T1-T2 terminals, the booster circuit portion A second IGBT Q2 connecting or disconnecting the first reactor L1 receiving the voltage and the output terminal of the first reactor L1 to the neutral N side according to the G2 / E2 control signal of the controller 70; To the fourth diode D4 and the charging capacitor C2 charged and boosted by the power generation voltage. It will be generated. The booster circuit unit generates a reactance counter voltage by turning on / off operation of the first reactor L1 by PWM control of the second IGBT Q2, and the positive voltage of the counter voltage is applied to the voltage V3 by the fourth diode D4. Charge the charging capacitor (C2) so that the voltage is about 400V.

In order to achieve the above object, the method of the present invention comprises the steps of detecting the generated voltage of the wind generator; Generating a first PWM control signal proportional to a generation voltage of the wind generator when the generation voltage of the wind generator is higher than a predetermined reference voltage; Controlling a dummy loader according to the first PWM control signal to process a brake operation to smoothly decelerate the blade of the wind generator; Detecting a power generation voltage of the wind power generator or a power generation voltage of the solar panel; If the generated voltage is a voltage in a normal range, transferring a generated voltage to an inverter; Generating a PWM control signal for turning on / off a reactor when the power generation voltage of the wind turbine or the power generation voltage of the solar panel is low; And outputting a normal voltage by charging the charging capacitor with the counter electromotive voltage of the reactor according to the PWM control signal.

The grid-connected inverter according to the present invention can support both a wind generator and a solar generator, and can supply extra generation power of a solar generator or a wind generator to the grid while being relatively less affected by weather, and wind and solar power. It protects the generator by breaking operation during overvoltage in power generation, and has an effect of increasing power generation efficiency by booster operation in low voltage. In addition, the inverter of the present invention can be applied to wind power inverters, solar power inverters, fuel power inverters and the like.

1 is a circuit diagram showing the entire circuit of the grid-connected inverter according to the present invention,
2 is a circuit diagram for processing a brake operation of a generator by PWM control of a dummy loader in a grid-connected inverter according to the present invention;
3 is a voltage waveform diagram of a generator in the circuit shown in FIG.
4 is a waveform diagram of a PWM pulse for controlling the IGBT in the circuit shown in FIG.
5 is a flowchart illustrating a brake control procedure in a grid-connected inverter according to the present invention;
6 is a booster circuit diagram in a grid-linked inverter according to the present invention,
7 is a flowchart illustrating a booster control procedure in a grid-connected inverter according to the present invention.

The technical problems achieved by the present invention and the practice of the present invention will be more clearly understood by the preferred embodiments of the present invention described below. The following examples are merely illustrative of the present invention and are not intended to limit the scope of the present invention. For example, the PWM control technique in the wind and photovoltaic power generation according to the present invention can be implemented in various forms, but in the embodiment of the present invention will be described taking an example implemented in a grid-connected interleaver.

1 is a circuit diagram showing the entire circuit of the grid-connected inverter according to the present invention.

As shown in FIG. 1, the grid-connected inverter according to the present invention receives a generation voltage of a wind generator or a solar panel voltage of a solar generator and transfers the result to the inverter, and the generation voltage of the wind generator rises to overvoltage due to overheating. When the overvoltage of the wind turbine is connected to the dummy loader according to the PWM control of the controller, the brake circuit unit 10 processes the brake operation to smoothly decelerate the blade of the wind generator, and the controller if the generated voltage of the wind generator or the solar generator is low. Booster circuit unit 20 for charging the capacitor under the control of the controller to increase the voltage, and inverter controlling the pulse width modulation (PWM) of the IGBT (Insulated Gate Bipolar mode Transistor) under the control of the controller. 30, and a filter that removes noise from the inverter output and outputs good sinusoidal power. 40, a power change unit 50 for transmitting the generated power to the system, a system power supply unit 60 for supplying power required by the system, and a DSP controller 70 for controlling the overall operation.

Referring to FIG. 1, the brake circuit unit 10 includes a dummy loader connected between a T1 terminal and a T2 terminal, a first diode D1 receiving the generated voltage of the wind generator as the T3 terminal, and transmitting the generated voltage in one direction, and solar light. A second diode D2 that receives the generator voltage from the generator and is transmitted in one direction, and a capacitor C1 connected between the first diode D1 and the second diode D2 and the T5 neutral terminal N; And a first IGBT (Q1) for connecting or disconnecting the dummy loader to the neutral terminal (N) according to the G1 / E1 PWM control signal of the controller, and a third diode (D3) connected in parallel between the T1-T2 terminals. It is composed.

The booster circuit unit 20 connects or disconnects the first reactor L1 receiving the generated voltage and the output terminal of the first reactor L1 to the neutral N side according to the G2 / E2 control signal of the controller 70. 2 IGBT Q2, a fourth diode D4, and a charging capacitor C2 that is charged by the power generation voltage and boosted.

The inverter circuit unit 30 is connected in a full bridge manner and is turned on / off according to the G3 / E3 control signals or the G6 / E6 control signals of the controller 70, and the third to sixth IGBTs Q3 to Q6. It consists of a second reactor (L2) connected to the output terminal of the sixth IGBT (Q3 ~ Q6).

The filter circuit unit 40 is composed of a filter (FILTER) and capacitors (C3, C4) connected in parallel to both ends of the filter, the power change circuit unit 50 and the first relay (RY1), the second resistor (R2) and Displays the second relay RY2, the manual switch SW1, the first resistor R1 connected to the second resistor R2 through the second relay RY2, and the sleep state of the inverter. It consists of LED (SLEEP LED).

The system power supply unit 60 is formed of a transformer having a primary winding connected to the filter output terminal and a rectifying diode and a smoothing capacitor connected to the secondary winding to supply system power required by the DSP controller 70 and the like.

In addition, the entire inverter circuit part includes a V1 signal line for transmitting the power generation voltage of the wind generator to the DSP controller 70, a V2 signal line for transmitting the solar panel voltage to the DSP controller 70, and a charging voltage of the charging capacitor C2. Signal line V3 for transmitting to the controller 70, signal line V3 for transferring the first line voltage of the filter 40 to the controller 70, signal line V5 for transferring the second line voltage of the filter 40 to the controller 70, and the brake circuit unit 10. ) CT1 signal line for sensing the current between the booster circuit unit 20 and transmitting it to the controller 70, CT2 signal line for detecting the current at the output terminal of the filter 40 and transmitting it to the controller 70, neutral (N). N signal line for connecting the line to the controller 70, G1 / E1 signal line for the controller 70 to control the first IGPT Q1, and G2 / for controller 70 to control the second IGPT Q2. E2 signal line, G for the controller 70 to control the third to sixth IGPTs Q3 to Q6. There are 3 / E3 to G6 / E6 signal lines, an RY1 signal line for the controller 70 to control the first relay RY1, and an RY2 signal line for the controller 70 to control the second relay RY2.

The controller 70 receives the V1 to V5 voltages and the CT1 and CT2 currents to control the first to sixth IGBTs Q1 to Q6, the first relay RY1, and the second relay RY2 according to a predetermined control algorithm. And communicates with other devices through the communication ports (RS, TS).

2 is a circuit diagram for processing a brake operation of a generator by PWM control of the dummy loader in the grid-connected inverter according to the present invention, Figure 3 is a voltage waveform diagram of the generator in the circuit shown in Figure 2, Figure 4 2 is a waveform diagram of a PWM pulse for controlling the IGBT in the circuit shown in FIG. 2, and FIG. 5 is a flowchart illustrating a brake control procedure in the system-linked inverter according to the present invention.

2 to 5, the input electricity of the wind power generator input to the terminal T3 is output (P1 + P3 path) to the DCV OUT through the first diode D1, and the solar solar panel SOLAR of the terminal T4. The input electricity of is transferred to the DCV OUT along the P2 path through the second diode (D2).

If the voltage V1 of the terminal T3, which is an input terminal of the wind power generator, continues to rise due to overheating and rises up to a reference voltage H _TH for detecting overpowering, the DSP controller 70 is shown in FIG. As described above, the first IGBT Q1 is PWM-controlled by reading the terminal voltage of V1, and the wind turbine voltage of T3 is sent to the dummy rod resistor through the path of P4-P5 to consume the generator voltage by heat exchange (S11 to S14).

In this case, the controller 70 generates a PWM pulse proportional to the magnitude of the voltage of the wind generator as shown in the waveforms of FIGS. 3 and 4 to control the PWM of the gate of the first IGBT Q1. Accordingly, the braid of the wind generator can smoothly decelerate to reduce mechanical shock and improve braid life. At this time, the PWM amount is controlled in proportion to the voltage of the wind generator, as shown in FIG.

FIG. 6 is a booster circuit diagram of a grid-connected inverter according to the present invention, and FIG. 7 is a flowchart illustrating a booster control procedure in the grid-connected inverter according to the present invention.

Meanwhile, when the wind power generation voltage is low because the wind is low or the solar voltage is lower than the reference voltage L _TH , the booster 20 of FIG. 6 may use the second IGBT (according to the PWM control signal of the controller 70). PWM control of Q2) causes the reactance counter voltage to be generated by the ON / OFF operation of the first reactor L1, and the positive voltage is charged through the fourth diode D4 until the charging voltage of V3 becomes about 400V. Charge the capacitor (C2) (S21 ~ S24).

When the voltage V3 reaches 400 V, the inverter 30 converts direct current into alternating current by the third to sixth IGBTs Q3, Q4, Q5 and Q6, and the first IGBT Q3 and the sixth IGBT Q6. ) Produces a positive (+) sine wave, and the fifth IGBT (Q5) and the fourth IGBT (Q4) produce a negative (-) sine wave.

In addition, the inverter 30 reads the amount of wind from the generator as the V1 voltage, calculates a maximum power point tracking (MPPT), and sends power to the system. It is detected and controlled by the same method and sent to the system (S25 ~ S28).

The present invention has been described above with reference to one embodiment shown in the drawings, but those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom.

10: brake circuit portion 20: booster circuit portion
30: inverter circuit portion 40: filter circuit portion
50: power change circuit 60: system power supply
70: Controller T1, T2: Dummy loader connection terminal
T3: Wind turbine input terminal T4: Solar panel voltage input terminal
T5: Neutral terminal T6, T7: Grid connection terminal

Claims (5)

In a PWM controller in wind or solar power generation, where a grid-connected inverter receives electricity from a wind generator or a solar generator, converts DC power into AC power and transmits it to the system by PWM controlling the power semiconductor switching element (IGBT). ,
It receives the power generation voltage of the wind generator or the solar panel voltage of the solar generator and transfers it to the inverter.When the power generation voltage of the wind generator rises to overvoltage due to the overwind, the overvoltage of the wind generator is connected to the dummy loader according to the PWM control of the controller. A brake circuit unit configured to process a brake operation to smoothly decelerate the braid of the wind generator;
A booster circuit unit configured to increase the voltage by charging the capacitor under the control of the controller when the generated voltage of the wind generator or the solar generator is low voltage; And
When the power generator voltage of the wind generator and the solar panel voltage of the solar generator are monitored and the power generator voltage of the wind generator rises to overvoltage due to overheating, a power semiconductor switching device connected between the dummy loader and the neutral line by a PWM pulse proportional to the power generation voltage. And if the power generation voltage of the wind generator or solar generator is a low voltage, PWM control the power semiconductor switching element connected to the first reactor is configured as a controller for charging the charging capacitor,
The brake circuit portion
A dummy loader connected between the T1 and T2 terminals, a first diode D1 that receives the generated voltage of the wind generator as the T3 terminal and transmits it in one direction, and receives the generated voltage of the solar generator as the T4 terminal in one direction. In accordance with the second diode (D2) to transfer, the capacitor (C1) connected between the first diode (D1) and the second diode (D2) and the T5 neutral terminal (N), according to the G1 / E1 PWM control signal of the controller In the wind or solar power generation, characterized in that it comprises a first IGBT (Q1) for connecting or disconnecting the dummy loader to the neutral terminal (N) and a third diode (D3) connected in parallel between the T1-T2 terminals PWM controller.
delete The method of claim 1, wherein the booster circuit portion
A first reactor L1 receiving the generated voltage and a second IGBT Q2 connecting or disconnecting the output terminal of the first reactor L1 to the neutral N side according to the G2 / E2 control signal of the controller 70; And a fourth diode (D4) and a charging capacitor (C2) charged and boosted by a power generation voltage.
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