CN102638061B - General charging controller for wind-light-diesel combined power supply system and control method thereof - Google Patents

Abstract

The invention relates to a general charge controller and a control method thereof for a combined power supply system of wind and firewood. The general charge controller includes a rectification filter circuit, a step-down chopper circuit, a fan unloading circuit and a control circuit. Among them, the fan unloading circuit and the input end of the rectification filter circuit are connected in parallel, and then connected to the input power supply; the control circuit is connected with the rectification filter circuit, step-down chopper circuit and fan unloading circuit through the control signal line, and the working power terminal of the control circuit is connected with the fan unloading circuit. The step-down chopper circuit is connected; the input end of the step-down chopper circuit is connected with the output end of the rectification circuit; the output end of the step-down chopper circuit is used as the output end of the charge controller, and is connected with the battery pack. The method is to determine which type of generator set to start by detecting the setting state of the DIP switch. The invention realizes the generalization and function integration of products, reduces the types of control equipment, improves the standardization degree of the system, is suitable for mass production and quality control in factories, and is convenient for users to use and manage and superiors to formulate allocation plans.

Description

A kind of universal charging controller and its control method for combined power supply system of wind and diesel

technical field

The invention relates to a charging controller used in a combined power supply system of wind and diesel, in particular to a general charging controller and a control method for the combined power supply of wind and diesel.

Background technique

At present, the charging control equipment of wind turbine, photovoltaic array and diesel generator combined power supply system (referred to as wind and diesel power supply system) is composed of single-function wind turbine charging controller, photovoltaic charging controller and diesel generator charging controller. There are many types of charging controllers, which are not easy to manage and maintain. After a certain type of controller fails, it cannot be replaced by other types of controllers, and the overall operation reliability is poor.

Contents of the invention

Aiming at the disadvantages of single function and other shortcomings in the charging controller for generators in the prior art, the technical problem to be solved by the present invention is to provide a universal charging controller and its Control Method.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

A universal charging controller for a wind-light diesel power supply system of the present invention includes: a rectification filter circuit, a step-down chopper circuit, a fan unloading circuit and a control circuit. Among them, the fan unloading circuit and the input end of the rectification filter circuit are connected in parallel, and then connected to the input power supply; the control circuit is connected with the rectification filter circuit, step-down chopper circuit and fan unloading circuit through the control signal line, and the working power terminal of the control circuit is connected with the fan unloading circuit. The step-down chopper circuit is connected; the input end of the step-down chopper circuit is connected with the output end of the rectification circuit; the output end of the step-down chopper circuit is used as the output end of the charge controller, and is connected with the battery pack.

The step-down chopper circuit uses IGBT as a switching device, the front end of the IGBT is connected to the output end of the rectification filter circuit, and the rear end is connected to the output end of the charging controller through a filter inductor, and the PWM signal of the IGBT is input by the IGBT drive circuit in the control circuit .

The control circuit includes a main control circuit and an IGBT drive circuit, wherein the main control circuit uses a digital signal controller as the control core, and its input terminal is connected with a signal detection circuit, a function selection circuit, a crystal oscillator circuit and a power supply circuit, and the output terminal is driven by an IGBT The circuit is connected to the PWM signal input end of the IGBT in the step-down chopper circuit.

The control method of the general charging controller of the wind-light diesel power supply system of the present invention comprises the following steps:

Determine which type of generator set to start by detecting the setting state of the DIP switch, that is, the main control circuit executes the photovoltaic charging control program, wind turbine charging control program or diesel engine charging control program, among which

The photovoltaic charging control program is:

Judging whether the rectified voltage in the rectification filter circuit, that is, the output value of the voltage signal 1 is greater than the threshold voltage;

If the output value of the voltage signal 1 is greater than the threshold voltage, detect the battery pack voltage;

When the voltage of the battery pack is greater than or equal to the equal charging voltage, the battery pack is evenly charged to the specified time;

Carry out float charging, go to the step of judging whether the output value of the voltage signal 1 is greater than the threshold voltage.

If the voltage of the battery pack is lower than the equalizing charging voltage, it is judged whether the voltage of the battery pack is lower than the over-discharge protection voltage;

If the battery pack voltage is not less than the over-discharge protection voltage, it is judged whether the global search has been carried out;

If the global search is not performed, the IGBT duty cycle is controlled to change from 0 to 1, and the global search is performed multiple times with a step size a to find the duty cycle λ _max that maximizes the output power of the photovoltaic array during multiple searches;

Control the IGBT work with the duty cycle λ _max ;

Judging whether the steady-state time exceeds the specified time, if it exceeds the specified time, then judge whether the output power has changed significantly;

If there is a large change, control the IGBT duty cycle from the lower limit to the upper limit, and perform a local search with a specified step size to find the duty cycle that maximizes the output power of the photovoltaic array during this search process;

Go to the step of judging whether the output value of the voltage signal 1 is greater than the threshold voltage.

If the output power does not change greatly or the steady-state time does not exceed the specified time, then go to the step of controlling the IGBT with the duty cycle λ _max .

If the global search has been carried out, the IGBT is directly controlled by the duty cycle λ _max , and then it is judged whether the steady-state time exceeds the specified time step.

If the battery pack voltage is lower than the over-discharge protection voltage, trickle charging is performed, and then the maximum power tracking control program steps are executed.

The charging control process of the fan is as follows:

Judging whether the output value of the voltage signal 1 is greater than the protection voltage;

If the output value of the voltage signal 1 is not greater than the protection voltage, then detect the battery pack voltage;

Judging whether the battery pack voltage is greater than or equal to the equalizing charging voltage;

When the voltage of the battery pack is greater than or equal to the equalization charging voltage, the battery pack is charged for the specified time;

Float charge the battery pack, go to the step of judging whether the output value of the voltage signal 1 is greater than the protection voltage.

When the voltage of the battery pack is not greater than or equal to the equalizing charging voltage, it is judged whether the voltage of the battery pack is less than the over-discharge protection voltage;

When the voltage of the battery pack is not less than the over-discharge protection voltage, the battery pack is charged normally;

Determine whether the charging current is greater than the protection current;

When the charging current is not greater than the protection current, all IGBTs are turned on for high current charging;

Go to the step of judging whether the input voltage of voltage signal 1 is greater than the protection voltage.

When the charging current is greater than the protection current, use the PID control algorithm to control the IGBT duty cycle to keep the charging current constant at the protection current;

Go to the step of judging whether the output value of the voltage signal 1 is greater than the protection voltage.

When the battery pack voltage is lower than the over-discharge protection voltage, trickle charge the battery pack;

Continue to the step of judging that the battery pack voltage is lower than the over-discharge protection voltage.

When the output value of the voltage signal 1 is greater than the protection voltage, the fan is unloaded.

Go to the step of judging whether the output value of the voltage signal 1 is greater than the protection voltage.

The charging control process of the diesel generator set is as follows:

Detect battery pack voltage;

Determine whether the voltage of the battery pack is lower than the over-discharge protection voltage;

When the battery pack voltage is lower than the over-discharge protection voltage, trickle charge the battery pack and go to the step of detecting the battery pack voltage.

When the battery pack voltage is not less than the over-discharge protection voltage, go to the step of detecting the battery pack voltage.

The present invention has the following beneficial effects and advantages:

1. The present invention realizes the generalization and function integration of products, reduces the types of control equipment, improves the standardization of the system, is suitable for mass production and quality control in factories, and is convenient for users to use and manage and superiors to formulate allocation plans.

2. The invention improves the maintenance interchangeability and reliability of the system control equipment. When the photovoltaic or wind turbine charging control module in the system fails, the charging control module of the diesel generator set can be used to replace it, so as to avoid the situation that the wind and solar power generation equipment in the system cannot work due to shutdown for repair, and ensure that the system can maximize the use of wind energy and solar energy resources.

Description of drawings

Fig. 1 is the schematic diagram of the universal charge controller circuit of the wind-light diesel power supply system of the present invention;

Fig. 2 is the functional block diagram of the control circuit in the universal charging controller of the present invention;

Fig. 3 is a flow chart of the control function selection program of the present invention;

Fig. 4 is the flow chart of photovoltaic charging control in the method of the present invention;

Fig. 5 is a flow chart of fan charging control in the method of the present invention;

Fig. 6 is a flow chart of the charging control of the diesel generator set in the method of the present invention.

Detailed ways

As shown in Fig. 1, the universal charging controller of the wind power diesel power supply system of the present invention includes: a rectification filter circuit, a step-down chopper circuit, a fan unloading circuit and a control circuit, wherein the input terminals of the fan unloading circuit and the rectification filter circuit are connected in parallel , connected to the input power supply (introduced by the input aviation plug in Figure 1), the control circuit is connected to the rectification filter circuit, step-down chopper circuit and fan unloading circuit through the control signal line (the electric energy of the wind turbine is input from the input aviation plug) Connection, the working power end of the control circuit is connected with the step-down chopper circuit (controlled by a circuit breaker); the input end of the step-down chopper circuit is connected with the output end of the rectifier circuit, and the output end of the step-down chopper circuit As the output terminal of the charge controller, it is connected with the battery pack.

In this embodiment, after the input electric energy of the wind power generator, photovoltaic array or diesel generating set is rectified by the three-phase rectifier bridge ZL1, it is filtered by two first and second capacitors C1 and C2 connected in series, and the first and second resistors R1 and R2 are used to balance the terminal voltage of the above two capacitors; the digital signal controller in the control circuit passes the information fed back by the signal detection circuit and the communication circuit, and the IGBT drive circuit controls the duty cycle of the switching device IGBT, and then is filtered by the inductor. Realize the adjustment of the output current, the third capacitor C3 is used to absorb the peak energy generated when the IGBT is turned off; when the input voltage of the fan is too high, the voltage of the battery pack is too high or the charging current is too large, the control circuit controls the second relay J2 to pull in , the two inputs of the fan are rectified by the transformer BYQ2 and the single-phase full-bridge circuit composed of the first to fourth diodes D1 to D4, and then charge the fourth capacitor C4. When the voltage of the fourth capacitor C4 rises to a certain value, it drives the first ～3 Thyristors DL1～DL3 open the three-phase rectification circuit, the fan is connected to the unloading circuit, and at the same time disconnect the aviation contactor J1 to complete the unloading control function of the fan. The second relay J2 is a normally closed relay. After the power supply is cut off, the fan is forcibly connected to the unloader. The voltage signal 2 in the figure is the output voltage of the step-down chopper circuit.

The step-down chopper circuit uses IGBT as a switching device, the front end of the IGBT is connected to the output end of the rectification filter circuit, and the rear end is connected to the output end of the charging controller through the filter inductor L, and the PWM signal of the IGBT is controlled by the IGBT drive circuit in the control circuit. enter.

The control circuit includes a main control circuit and an IGBT drive circuit, wherein the main control circuit uses a digital signal controller as the control core, and its input terminal is connected with a signal detection circuit, a function selection circuit, a crystal oscillator circuit and a power supply circuit, and the output terminal is driven by an IGBT The circuit is connected to the PWM signal input end of the IGBT in the step-down chopper circuit.

The signal detection circuit includes a temperature detection circuit, a current detection circuit and a voltage detection circuit, wherein the current signal of the current detection circuit comes from the current transformer in the rectification filter circuit and the step-down chopper circuit, and the temperature signal of the temperature detection circuit comes from the device The temperature sensor on the surface of the IGBT radiator; the voltage signal of the voltage detection circuit comes from the voltage measurement circuit 1 and the voltage measurement circuit 2.

The function setting circuit is a dial switch (a 2-bit dial switch is used in this embodiment), which is connected to the data pin of the digital signal controller.

The power supply circuit is connected with corresponding pins of the digital signal controller.

It also has a man-machine interface circuit and/or a serial port. The digital signal controller interacts with the user through the man-machine interface circuit, or communicates with external devices (such as a DC monitoring module) through the serial port.

As shown in Figure 2, the control unit uses the dsPIC30F digital signal controller as the control core, and has built-in photovoltaic charging maximum power tracking control program, fan charging and unloading control program, and diesel engine charging control program. The peripheral circuit includes signal detection circuit, function setting circuit, communication circuit, IGBT drive circuit, crystal oscillator circuit and power supply circuit, etc. The digital signal controller selects different control programs through the setting state of the 2-bit dial code in the detection function setting circuit, and controls the duty cycle of the switching device IGBT through the IGBT drive circuit; the voltage detection circuit uses a high-precision linear optocoupler The components detect voltage signals, and the voltage detection circuit uses a ring transformer to detect current signals; the communication circuit uses a MAX485 chip and a dedicated protocol to exchange information with the outside world.

As shown in Fig. 3, the control method of the universal charge controller of the wind power diesel power supply system of the present invention includes the following steps:

Determine which type of generator set to start by detecting the setting state of the dial switch, that is, the main control circuit executes the photovoltaic charging control program, wind turbine charging control program or diesel engine charging control program, wherein: when the setting state of the dial switch is 00 , the main control circuit executes the photovoltaic charging control program; when the setting state of the 2-digit DIP switch is 01, the main control circuit executes the fan charging control program; when the setting state of the 2-digit DIP switch is 10, the main control circuit Execute the diesel engine charging control program.

As shown in Figure 4, the photovoltaic charging control program is:

Judging whether the output value of the rectified voltage (i.e. the voltage signal 1 shown in Figure 1) in the rectification filter circuit is greater than the threshold voltage (300V);

If the output value of the voltage signal 1 is greater than the threshold voltage (300V), detect the battery pack voltage;

When the voltage of the battery pack is greater than or equal to the equal charging voltage, the battery pack is evenly charged to the specified time;

Carry out float charging, go to the step of judging whether the output value of voltage signal 1 is greater than the threshold voltage (300V).

If the voltage of the battery pack is lower than the equalizing charging voltage, it is judged whether the voltage of the battery pack is lower than the over-discharge protection voltage;

If the battery pack voltage is not less than the over-discharge protection voltage, it is judged whether the global search has been carried out;

If the global search is not performed, the IGBT duty cycle is controlled to change from 0 to 1, and the global search is performed multiple times with a step size a to find the duty cycle λ _max that maximizes the output power of the photovoltaic array during multiple searches;

Control the IGBT work with the duty cycle λ _max ;

Determine whether the steady-state time exceeds the specified time (3min), if it exceeds the specified time, then determine whether the output power has changed significantly;

If there is a large change, the IGBT duty cycle is controlled to change from the lower limit (0.9λ _max ) to the upper limit (1.1λ _max ), and a local search is performed with a specified step size (a/10) to find out the photovoltaic power during this search process. The duty cycle of the maximum output power of the square array;

Go to the step of judging whether the output value of the voltage signal 1 is greater than the threshold voltage (300V).

If the output power does not change significantly or the steady-state time does not exceed the specified time, go to the duty cycle λ _max to control the IGBT working step;

If the global search has been carried out, the IGBT is directly controlled by the duty cycle λ _max , and then the step of judging whether the steady state time exceeds the specified time (3min) is continued;

If the battery pack voltage is lower than the over-discharge protection voltage, trickle charging is performed, and then the maximum power tracking control program steps are executed.

As shown in Figure 5, the wind turbine charging control process is as follows:

Judging whether the output value of voltage signal 1 is greater than the protection voltage (800V);

If the output value of voltage signal 1 is not greater than the protection voltage, connect the aviation contactor J1, disconnect the second relay J2, and detect the voltage of the battery pack;

Judging whether the battery pack voltage is greater than or equal to the equalizing charging voltage;

When the voltage of the battery pack is greater than or equal to the equalization charging voltage, the battery pack is charged for the specified time;

Float charge the battery pack, go to the step of judging whether the output value of the voltage signal 1 is greater than the protection voltage (800V).

When the voltage of the battery pack is not greater than or equal to the equalizing charging voltage, it is judged whether the voltage of the battery pack is less than the over-discharge protection voltage;

When the voltage of the battery pack is not less than the over-discharge protection voltage, the battery pack is charged normally;

Determine whether the charging current is greater than the protection current (42A);

When the charging current is not greater than the protection current, all IGBTs are turned on for high current charging;

Go to the step of judging whether the input voltage of voltage signal 1 is greater than the protection voltage (800V).

When the charging current is greater than the protection current, use the PID control algorithm to control the IGBT duty cycle to keep the charging current constant at the protection current (42A);

Go to the step of judging whether the output value of voltage signal 1 is greater than the protection voltage (800V).

When the battery pack voltage is lower than the over-discharge protection voltage, trickle charge the battery pack;

Continue to the step of judging that the battery pack voltage is lower than the over-discharge protection voltage.

When the output value of the voltage signal 1 is greater than the protection voltage (800V), the aviation contactor J1 is disconnected, and the first relay J2 is engaged to unload the fan.

Go to the step of judging whether the output value of the voltage signal 1 is greater than the protection voltage.

As shown in Figure 6, the charging control process of the diesel generator set is as follows:

Detect battery pack voltage;

Determine whether the voltage of the battery pack is lower than the over-discharge protection voltage;

When the battery pack voltage is lower than the over-discharge protection voltage, trickle charge the battery pack and go to the step of detecting the battery pack voltage;

When the battery pack voltage is not less than the over-discharge protection voltage, go to the step of detecting the battery pack voltage.

Claims (11)

1. A control method for a general-purpose charge controller of a wind-and-firewood power supply system, said general-purpose charge controller for a wind-and-firewood power supply system, comprising: a rectifier filter circuit, a step-down chopper circuit, a blower fan unloading circuit, and a control circuit; wherein the blower blower unloads After the input terminals of the load circuit and the rectification and filter circuit are connected in parallel, they are connected to the input power supply; the control circuit is connected with the rectification and filter circuit, the step-down chopper circuit and the fan unloading circuit through the control signal line, and the working power of the control circuit is connected with the step-down chopper Circuit connection; the input end of the step-down chopper circuit is connected with the output end of the rectification filter circuit; the output end of the step-down chopper circuit is used as the output end of the charge controller and connected with the battery pack; The control circuit includes a main control circuit and an IGBT drive circuit, wherein the main control circuit uses a digital signal controller as the control core, and its input terminal is connected with a signal detection circuit, a function selection circuit, a crystal oscillator circuit and a power supply circuit, and the output is driven by an IGBT The circuit is connected to the PWM signal input end of the IGBT in the step-down chopper circuit; The function selection circuit is a dial switch; The step-down chopper circuit uses IGBT as a switching device, the front end of the IGBT is connected to the output end of the rectification filter circuit, and the rear end is connected to the output end of the charging controller through a filter inductor (L), and the PWM signal of the IGBT is controlled by the IGBT in the control circuit. drive circuit input; It is characterized in that the control method includes the following steps: Determine which type of generator set to start by detecting the setting state of the DIP switch, and the main control circuit executes the photovoltaic charging control step, the fan charging control step or the diesel engine charging control step, wherein The photovoltaic charging control steps include: Judging whether the rectified voltage in the rectification filter circuit, that is, the output value of the first voltage signal is greater than the threshold voltage; If the output value of the first voltage signal is greater than the threshold voltage, detecting the battery pack voltage; When the voltage of the battery pack is greater than or equal to the equalizing charging voltage, the battery pack is charged for equalizing for the specified time; Carry out floating charging, go to the step of judging whether the output value of the first voltage signal is greater than the threshold voltage; If the voltage of the battery pack is lower than the equalizing charging voltage, it is judged whether the voltage of the battery pack is lower than the over-discharge protection voltage; If the battery pack voltage is not less than the over-discharge protection voltage, it is judged whether the global search has been carried out; If no global search is performed, the IGBT duty cycle is controlled to change from 0 to 1, and the global search is performed multiple times with a step size a, to find the duty λ _max that maximizes the output power of the photovoltaic array during multiple searches; Control the IGBT work with the duty cycle λ _max ; Determine whether the steady-state time exceeds the specified time, and if it exceeds the specified time, then determine whether the output power has changed significantly; If there is a large change, control the IGBT duty cycle from the lower limit to the upper limit, and perform a local search with a specified step size to find the duty cycle that maximizes the output power of the photovoltaic array during this search process; Go to the step of judging whether the output value of the first voltage signal is greater than the threshold voltage. 2. The control method of the universal charge controller of the wind and diesel power supply system according to claim 1, characterized in that: if the output power does not change significantly or the steady-state time does not exceed the specified time, then turn to the duty cycle λ _max controls the IGBT work steps. 3. according to the control method of the general charging controller of the wind and diesel power supply system of claim 1, it is characterized in that: if the global search has been carried out, then directly control the IGBT work with the duty cycle λ _max , and continue to judge whether the steady-state time exceeds Specify the time steps. 4. The control method of the universal charging controller for the wind power diesel power supply system according to claim 1, characterized in that: if the battery pack voltage is lower than the over-discharge protection voltage, trickle charging is performed, followed by the maximum power tracking control step. 5. according to the control method of the general charging controller of the wind and diesel power supply system according to claim 1, it is characterized in that the charging control step of the fan comprises: Judging whether the output value of the first voltage signal is greater than the protection voltage: If the output value of the first voltage signal is not greater than the protection voltage, the battery pack voltage is detected: When it is judged that the voltage of the battery pack is greater than or equal to the equalization charging voltage, the battery pack is equalized to the specified time; Float charge the storage battery pack, go to the step of judging whether the output value of the first voltage signal is greater than the protection voltage. 6. The control method of the general charging controller of the wind power diesel power supply system according to claim 5, wherein the charging control step of the fan further comprises: When the voltage of the battery pack is not greater than or equal to the equalizing charging voltage, it is judged whether the voltage of the battery pack is less than the over-discharge protection voltage; When the voltage of the battery pack is not less than the over-discharge protection voltage, the battery pack is charged normally; Determine whether the charging current is greater than the protection current; When the charging current is not greater than the protection current, all IGBTs are turned on for high current charging; Go to the step of judging whether the output value of the first voltage signal is greater than the protection voltage. 7. The control method of the general charging controller of the wind power diesel power supply system according to claim 6, characterized in that: the wind turbine charging control step also includes: When the charging current is greater than the protection current, use the PID control algorithm to control the IGBT duty cycle to keep the charging current constant at the protection current; Go to the step of judging whether the output value of the first voltage signal is greater than the protection voltage. 8. The control method of the universal charge controller for the wind power diesel power supply system according to claim 6, characterized in that: the wind turbine charging control step further comprises: when the voltage of the battery pack is less than the over-discharge protection voltage, trickle current to the battery pack Charge; Continue to the step of judging that the battery pack voltage is lower than the over-discharge protection voltage. 9. The control method of the universal charge controller of the wind and diesel power supply system according to claim 5, characterized in that: the wind turbine charging control step further comprises: when the output value of the first voltage signal is greater than the protection voltage, the power supply to the wind turbine unloading; Go to the step of judging whether the output value of the first voltage signal is greater than the protection voltage. 10. The control method of the universal charging controller of the wind and diesel power supply system according to claim 1, characterized in that: the diesel engine charging control step comprises: Detect battery pack voltage; Determine whether the voltage of the battery pack is lower than the over-discharge protection voltage; When the battery pack voltage is lower than the over-discharge protection voltage, trickle charge the battery pack and go to the step of detecting the battery pack voltage. 11. The control method of the universal charging controller of the wind power diesel power supply system according to claim 10, characterized in that: the diesel engine charging control step further includes: when the voltage of the battery pack is not less than the over-discharge protection voltage, go to the detection battery Group voltage steps.