CN2672938Y - Independently operating solar energy photovoltaic power station controller - Google Patents

Abstract

A solar photovoltaic power plant controller that operates independently, consists of two parts: the main circuit and the control drive circuit: the main circuit adopts a DC-DC conversion circuit, the control drive circuit adopts an analog and digital hybrid circuit, and the analog part realizes the drive and protection of the main circuit. The digital part realizes the charging management algorithm, and realizes the maximum power tracking technology in the charging process, and the driving signal of the analog part is given by the charging algorithm. At the same time, the utility model has liquid crystal display, keyboard operation and communication functions. The utility model has the advantages of: the idea of modular design, the capacity of the photovoltaic power station can be arbitrarily expanded, and it is suitable for mass production; the analog and digital hybrid circuit has a compact structure, complete functions, and high reliability; according to the characteristics of the solar cell, it can effectively control the charging of the storage battery process; make full use of solar resources, improve charging efficiency, and reduce system costs; effectively manage the battery charging process and increase battery life.

Description

A controller for independently operating solar photovoltaic power plants

technical field

The utility model relates to a solar photovoltaic power station controller, in particular to a solar photovoltaic power station controller which operates independently.

Background technique

With the development of my country's photovoltaic industry, the use of independently operated solar photovoltaic power generation systems plays an increasingly important role in solving the problems of remote areas and island residents far away from the power grid, power supply for communication facilities, cathodic protection of oil pipelines, and domestic power consumption for frontier defense forces. The controller is an important part of the independent operation of the solar photovoltaic power generation system, and its performance will directly affect the use effect of the solar photovoltaic power generation system. The main function of the controller is to realize battery charge and discharge management, maintain the power supply balance of the photovoltaic system, maintain the safety of the supporting equipment of the system, make full use of solar energy resources, improve the efficiency of photovoltaic power supply, and prolong the service life of supporting equipment.

The controllers designed and developed abroad are relatively miniaturized. Some controllers only have the control circuit part, and the main circuit part often needs to be configured separately, and most circuits adopt on-off control. Power tracking, but the voltage level is low, and it is relatively small, and it is not easy to expand. It is only suitable for small household photovoltaic power supply systems. There are mainly two kinds of control technologies widely used in the controllers used in China. One is to control the relay in a multi-channel control mode by a simple analog circuit. The charge and discharge control of the battery is mainly realized by detecting the battery voltage. When the solar cell square array charges the battery to the allowable upper limit, the charging is cut off; when the load discharge causes the battery voltage to drop to the protection value, the output is cut off. The disadvantage of this control technology is that due to the fluctuation of the battery voltage, the relay switch will be switched frequently, the failure rate is high, the battery charging process is difficult to realize, the charging efficiency is low, and the performance of the solar battery is not considered; the second is to use MOSFET or IGBT The equal-power device controls the power device to turn on and off to charge the battery by judging the battery voltage, and uses PWM pulse width modulation to limit the current when the charging current is large. Although this method improves the charging management of the battery, because the solar battery is affected by temperature, sunlight intensity, and load, it is an unstable power supply system. The controller does not fully consider the characteristics of the solar battery for charging management and limited utilization. The solar energy resources are used to improve the charging efficiency and reduce the system cost, so this control method also has obvious disadvantages.

Utility model content

The purpose of the utility model is to provide a new type of independent operation solar photovoltaic power station controller, and optimize the design of the current solar photovoltaic power station controller. The controller adopts a modular design, no need to design controllers with different capacities, and the capacity of the photovoltaic power station can be expanded arbitrarily. The utility model is mainly composed of a main circuit and a control driving circuit: the main circuit adopts a DC-DC conversion circuit, the control driving circuit adopts an analog and digital hybrid circuit, the analog part realizes the driving and protection of the main circuit, and the digital part realizes charging management Algorithm, the maximum power tracking technology is realized in the charging process, and the driving signal of the analog part is given by the charging algorithm. At the same time, the utility model has liquid crystal display, keyboard operation and communication functions.

Compared with the above-mentioned controller circuit, the utility model has the following advantages:

1. Modular design idea, can expand the capacity of photovoltaic power station arbitrarily, suitable for mass production;

2. Analog and digital mixed circuit, compact structure, complete functions, high reliability;

3. According to the characteristics of solar cells, effectively control the battery charging process;

4. Make full use of solar energy resources, improve charging efficiency and reduce system costs;

5. Effectively manage the charging process of the battery and improve the service life of the battery.

The utility model not only completes the basic functions that the controller needs to realize, but also according to the characteristics of the solar photovoltaic power generation system, the hardware circuit adopts a hybrid circuit structure, realizes the maximum power point tracking, and solves the shortcomings of the above-mentioned photovoltaic power station controller.

Description of drawings

Figure 1 is a block diagram of a solar photovoltaic system.

Fig. 2 is the functional block diagram of the controller of the present utility model.

Fig. 3 is a circuit diagram of a specific embodiment of the controller of the present invention.

Fig. 4 is a schematic diagram of the main circuit control part of the utility model.

Fig. 5 is a schematic diagram of the utility model microprocessor and its extensions.

Fig. 6 is a schematic diagram of the auxiliary power supply part of the utility model.

Fig. 7 is a functional block diagram of battery charging management and maximum power tracking coordination of the utility model.

Detailed ways

The utility model will be further described below in conjunction with the accompanying drawings and specific embodiments.

Figure 1 is a schematic diagram of a solar photovoltaic power plant system. As shown in the figure, the photovoltaic array is composed of solar cell components, which generate direct current under the irradiation of sunlight, charge the battery through the controller, and supply power to the inverter at the same time, when the light radiation is weak or there is no sunlight Next, the battery directly supplies power to the inverter through the controller, and the inverter converts direct current into alternating current to supply power to the load. The main function of the controller is to adjust and control the photovoltaic voltage and current to charge the battery, and at the same time, it has the protection function of overcharging and over-discharging the battery.

The functional block diagram of the controller of the utility model is shown in Figure 2: it is mainly composed of a DC-DC conversion main circuit, a drive isolation circuit, an integrated PWM and protection circuit, a micro-processing control circuit and an auxiliary power supply circuit. The main circuit adopts DC-DC conversion circuit. The drive isolation is mainly used for drive amplification and isolation of power devices. The integrated PWM and protection circuit is mainly used for drive and over-current protection of power devices and feedback to the microprocessor for over-current faults; The control circuit estimates the capacity of the battery by collecting the voltage and current of the battery, and combines the maximum power tracking output PWM waveform to manage the charging of the battery. The drive isolation circuit, integrated PWM and protection circuit, and auxiliary power supply circuit constitute the analog control part, and the microprocessor circuit, keyboard display circuit and communication circuit constitute the digital control circuit, as shown in the block diagram of the controller in Figure 2. Part A and Part B .

The specific implementation of the utility model controller circuit is shown in Figure 3: it consists of a DC-DC conversion main circuit 1, a drive isolation circuit 2, an integrated PWM and protection circuit 3, a micro-processing control circuit 4 and an auxiliary power supply circuit 5. The DC-DC conversion main circuit 1 is respectively connected with the driving isolation circuit 2, and the output voltage 19 and the output current 14 of the output terminal of the DC-DC conversion main circuit 1 are respectively connected with the circuit 20 and the circuit 6 of the integrated PWM and protection circuit 3, and the DC-DC The conversion main circuit 1 is respectively connected with the driving isolation circuit 2, the input voltage 18 and the input current 17 of the input terminal of the DC-DC conversion main circuit 1 are respectively connected with a and b of the limiter circuit 7 of the micro-processing control circuit 4, and the battery voltage 15 and The storage battery current 16 is respectively connected to d and c of the circuit 7 of the microprocessing control circuit 4 . The driving isolation circuit 2 is connected with the DC-DC conversion main circuit 1 and the auxiliary power supply circuit 5 respectively, the 22 circuit and the 23 circuit of the driving isolation circuit 2 are connected with the circuit 21 of the DC-DC conversion main circuit 1, and the 9, 23 circuits of the auxiliary power supply circuit 5 are connected. 10 circuits. The integrated PWM and protection circuit 3 are respectively connected to the driving isolation circuit 2, the microprocessor control circuit 4, and the auxiliary power supply circuit 5, and the circuit 24 of the integrated PWM and protection circuit 3 is connected to the circuit 22, the circuit 23 and the auxiliary power supply circuit of the driving isolation circuit 2 The circuit 11 of 5 is connected to the circuit 24 of the integrated PWM and protection circuit 3 and the circuits 26 and 27 of the micro-processing control circuit 4, and is connected to the PI regulating circuit 20 and the current amplification circuit 6. The microprocessing control circuit 4 is respectively connected with the auxiliary power supply circuit 5, collecting battery voltage 15, battery current 16, main circuit input voltage circuit 17 (photovoltaic array voltage), and main circuit input current circuit 18 (photovoltaic array current). 25 circuits of the microprocessing control circuit 4 are connected with 12 of the auxiliary power supply circuit, and the 25 circuits of the microprocessing control circuit 4 are respectively connected with the A/D conversion limiting circuit 7, the isolation input circuit 26, the isolation output circuit 27, the PC communication circuit, The keyboard operation is connected to the LCD display circuit and the LED display circuit, and the circuit 25I/O output over-discharge control circuit e is connected to the storage battery output control circuit 46 .

The DC-DC conversion main circuit 1 shown in FIG. 4 is composed of two sets of DC-DC conversion circuits 21 with a common negative pole. The DC-DC conversion circuit 1 is composed of a power switch tube 28, a diode 29, a filter inductor 30, and a filter capacitor 31. The two groups of circuits have two pairs of power switch tubes 28, diodes 29, filter inductors 30, and filter capacitors 31. The output voltage and output current are controlled by driving the power switch tube 28 on and off by the drive waveform, the diode 29 has a freewheeling effect, and the filter inductor 30 makes the power switch tube work in the continuous and intermittent state of the inductor current, and the filter inductor 31 filters out output ripple. The input end of the main circuit is a solar photovoltaic cell, and the output end enters the storage battery.

The drive isolation circuit 2 as shown in Figure 3 is made up of isolation amplifier circuits 22 and 23, the isolation amplifier circuits 22 and 23 are respectively connected to the power device drive terminals of the two main circuits, and the isolation amplifier circuit optical couplers 22 and 23 are powered by the auxiliary power supply 9 and 10 respectively provide +15V power for amplifying drive.

The integrated PWM and protection circuit 3 shown in FIG. 3 is composed of an integrated PWM circuit 24 , a current amplification circuit 6 , a main circuit output sampling voltage circuit 19 and a voltage regulation circuit 20 . The integrated PWM circuit 24 is a core device, which can realize more functions. The integrated PWM circuit 24 realizes the main circuit protection function through the feedback monitoring voltage and current signals, and the +15V power supply voltage provided by the auxiliary power supply 11 is supplied to the integrated PWM circuit. 24 power supply, receiving the voltage regulation signal 27 sent by the microprocessor, the output current of the main circuit collected by the shunt 14 is sent to the integrated PWM circuit 24 through the current amplifier circuit 6, and the change of the current is monitored by the internal comparison circuit, and the overcurrent and short circuit Response; the output voltage of the main circuit is collected by the sampling voltage circuit 19, and sent to the integrated PWM circuit 24 through the PI regulating circuit 20, and the integrated PWM circuit 24 adjusts the conduction time of the power switch tube through voltage feedback to stabilize the output.

Described microprocessor control circuit 4 as shown in Figure 3 is by microprocessor and its extension circuit 25, analog quantity input limiting circuit 7, analog quantity output PWM isolation filter circuit 27, the protection that is made of integrated PWM circuit 24 The circuit feedback is composed of an isolated input circuit 26, a PC communication serial port, a keyboard, and an LCD display. The microprocessor and its expansion circuit 25 are respectively connected to the analog input limiter circuit 7, the analog output PWM isolation filter circuit 27, the feedback isolation input circuit 26, and the PC communication serial port, keyboard, and LCD display.

The microprocessor of described microprocessor control circuit 4 as shown in Figure 5 and expansion circuit 25 thereof are by main controller Intel chip 4080C196MC, two address expansion bus chips 36,37, data bus chip 38, RAM expansion chip 35 and ROM expansion chip 39, keyboard and LCD display expansion chip 40, A/D conversion circuit 32, D/A conversion circuit 33 (PWMO), LED display expansion chip 41 form. In addition, it also includes input and output I/O circuits 48, 47, and a serial port circuit 45 for communication with the PC. In the above circuits, the main control chip is usually connected to the expansion address bus, data bus, keyboard and LCD expansion, and the D/A conversion circuit itself has A/D and D/A conversion circuits, input and output I/O circuits. A/D conversion circuit 33 (PWMO) is connected to analog output PWM isolation filter circuit 27, D/A conversion circuit 32 is connected to analog input limiting circuit 7, keyboard and LCD display expansion chip 40 is connected to keyboard 42 and LCD 43, LED display The expansion chip 41 is connected to the LED display 44, and the input I/O circuit 48 is connected to the protection circuit feedback isolation input circuit 26. It is composed of two 8-bit address expansion bus chips 36 and 37. The 16-bit address bus is connected to the RAM expansion chip 35 and the ROM expansion chip. 39. The data bus chip 38 is connected to the RAM expansion chip 35, the ROM expansion chip 39, the keyboard and LCD display expansion chip 40, and the LED display expansion chip 41 respectively.

As shown in FIG. 3 , the auxiliary power supply circuit 5 is a flyback switching power supply with multiple outputs, and is composed of voltage stabilizing circuits 9 , 10 , 11 , 12 and a main circuit 13 . The voltage stabilizing circuits 9, 10, 11, 12 are connected to the main circuit 13 to provide high-quality power, the voltage stabilizing circuit 9 is connected to the isolation amplifier circuit 22 driving the isolation circuit 2, and the voltage stabilizing circuit 10 is connected to the isolation amplifier circuit driving the isolation circuit 2 23, the voltage stabilizing circuit 11 is connected to the integrated PWM circuit 24 of the integrated PWM and protection circuit 3, the voltage stabilizing circuit 12 is connected to the microprocessor of the microprocessor control circuit 4 and its expansion circuit 25, and the primary side of the main circuit 13 is powered by the battery voltage , the secondary side is connected to the voltage stabilizing circuits 9, 10, 11, 12 after being rectified and filtered.

The main circuit 13 of the described auxiliary power supply circuit 5 as shown in Figure 6 is by short circuit, overcurrent protection circuit 28, single-channel input multiple output power frequency transformer circuit 30, rectification circuit 50,51,52,53, filter circuit 54 , 55, 56, 57, power switch tube 31, PWM control circuit 29 form. The PWM control circuit 29 is a core device and has multiple functions. By regulating the power switch tube 31, the transformer can output a stable AC voltage. Its peripheral detection and PI regulation circuits need to be expanded to realize its powerful functions. The overcurrent protection 28 is connected to the battery input, and then connected to the primary side of the power frequency transformer circuit 30, the lower end of the primary side of the down frequency transformer circuit 30 is connected to the power switch tube 31, and the power switch tube 31 is connected to the PWM control circuit 29, and the power frequency transformer circuit 30 The output of the secondary side is connected to the rectification circuits 50, 51, 52, 53, and after the rectification output, the filter circuits 54, 55, 56, 57 are respectively connected to the voltage stabilizing circuits 9, 10, 11, 12, and finally the required DC voltage is output.

Further describe the working process of the present invention below:

The positive terminal of the solar cell group with two common cathodes passes through the anti-reverse diode and then enters the main circuit, and the main circuit is formed by connecting two BUCK circuits with common negative poles. The main circuit power switch tube 28 is driven by the driving circuit 22, 23, and the driving circuit drives the main circuit according to the output of the dedicated PWM integrated circuit 24, and the output of the dedicated PWM integrated circuit 24 is controlled by the A/D circuit 33 of the microprocessor circuit 25. Give a given value to adjust, and the main circuit works according to the designed output voltage and current value. The working process of part A and part B shown in the original block diagram of the controller in Figure 2 will be described in detail below.

Part A, namely the analog control part, takes the dedicated PWM integrated circuit 24 as the core, and the dedicated PWM integrated circuit 24 outputs two driving signals, which are isolated and amplified by the optical coupler 22 and 23 to drive the switching device 28 in each BUCK branch. The dedicated PWM integrated circuit 24 is provided by the auxiliary power supply circuit 9. The PWM waveform output by the microprocessor 25 is isolated by the filter circuit and the optical coupler. After the PI is adjusted and stabilized, it is sent to the dedicated PWM integrated circuit 24. The on-time is used to adjust the output voltage and current, and adjust the output voltage to a given value. Simultaneously detect the feedback voltage and feedback current of the main circuit. After the feedback voltage is divided by the output voltage through the resistance of the circuit 19, the control voltage is compared with the periodic waveform to output the pulse width modulation wave. The circuit 24 realizes the output voltage stabilization. Feedback current detection adopts shunt 14 and sends it to dedicated PWM integrated circuit 24 after being amplified by LM358 circuit 6 . The PWM integrated circuit 24 has a comparison circuit. When the current exceeds the set value, the dedicated PWM integrated circuit 24 will immediately protect and block the PWM output. Meanwhile, the isolation circuit 26 notifies the microprocessor to stop the PWM output to protect the main circuit power switch tube 28. The auxiliary power supply of the analog control part is more important. There are many output voltages. The main circuit adopts a single-ended flyback switching power supply. The power switching device adopts MOSFET 31, through the power frequency transformer 30 with single-channel input and multiple output of flyback, there are 3 channels of direct current output on the secondary side, through half-wave rectification circuits 50, 51, 52, 53, and filter capacitors 54, 55 , 56, 57, after the 7812 chip 9, 10, 11 stabilized voltage, output 3 roads of 15 volts of direct current power supply, after the 7805 chip 12 voltage stabilized output of 1 road of 5 volts of direct current power supply, for the dedicated PWM integrated circuit 24 and drive in the back The amplifying circuits 22 and 23 work and supply the microprocessor circuit 25 as power. The integrated PWM and protection circuit 3 adopts SG3525A, the optocouplers 22 and 23 adopt TLP250, and the shunt is FLQ88-30A/47mA.

The digital control part B adopts Intel 80C196MC 16-bit microprocessor as the main controller chip. This processor not only has multiple A/D conversion circuits, but also has a waveform generator (WG) with 6 outputs, which is especially suitable for controlling three-phase AC motors and various bridge inverter circuits also have two kinds of PWM output. In addition, 80C196MC has an external protection interrupt function, which provides real-time protection for overcurrent, short circuit, and overvoltage of the main circuit, and has programmable dead time To set the function, as long as the pulse width corresponding to the pulse width modulation signal is input into the corresponding register, the pulse width modulation can be realized.

The digital control part B of the utility model adopts Intel80C196 chip 40 as the control core, configures extended RAM36 and extended ROM39, 8255 chip 40 extends keyboard and LCD display, collects photovoltaic voltage 17 and photovoltaic current 18 by Hall element and collects busbar by LEM module Both the battery voltage 15 and the current 16 are converted into standard voltage signals, which are sent to the D/A port 32 for acquisition and calculation after being passed through the limiter circuit 7 . The I/O port output control line is connected to the LCD display 43, and the output switching value controls the DC contactor to prevent the battery from being over-discharged. The I/O port 48 inputs the fault signal provided by the analog control part through the isolation circuit 26 to block the output signal. Protection function, and the alarm is displayed on the LCD at the same time. LED 44 shows that the controller works normally (green) and fails (red), connected by 74LS377 expansion chip 41, 80C196MC chip 40 obtains battery voltage, battery current, photovoltaic voltage, photovoltaic current, ambient temperature, etc. through D/A conversion 33 Battery status, output adjustable PWM waveform through A/D conversion 33, at the same time, software programming realizes the control algorithm of the battery charging process (including the maximum power tracking control algorithm), and converts the charging algorithm into PWM output, which is controlled by its own A/D The D conversion circuit 33 outputs PWM control waveforms, the output waveforms are filtered by the 6N136 chip 27, isolated by the optical coupler, and the output of the integrated PWN chip 24 is controlled to drive the main circuit, and the output voltage of the main circuit is adjusted to a given value. The 80C196 chip also configures the MAX232 communication interface chip 45 to communicate with the PC, select and view the current operating data through the keyboard operation 42, modify the battery protection point setting, and view the operating parameters and historical data through the LCD circuit 43.

The following describes the control algorithm of the battery charging process, which is described in detail in three stages:

(1) When the battery voltage is detected to be lower than a certain value, the controller starts charging. During this process, the microprocessor adopts maximum power tracking to ensure the maximum power output of the solar battery. Using the method of fixing the voltage tracking point, first determine the output voltage value Vref of the solar battery when the solar battery works at the maximum power point, and then change the charging current of the solar battery to the battery to stabilize the solar battery at Vref, and realize the maximum power tracking (detailed introduced later). At the same time, the battery voltage and battery charging current are monitored in real time, and the battery capacity is estimated by the battery current. When the battery voltage reaches a certain value and the battery charging current decreases to a certain level, the maximum power tracking is stopped and the charging process is transferred to the next stage. When the light is strong, the voltage of the battery rises rapidly. Monitor the charging current of the battery. At this time, the charging current of the battery is still high, indicating that the charging capacity of the battery does not meet the requirements at this time. PWM modulation is required to limit the charging current, lower the battery voltage, and continue charging. , This avoids cutting off the input only by detecting the falsely high voltage of the storage battery, resulting in waste of energy and insufficient charging of the storage battery.

(2) At this stage, the maximum power tracking can no longer be carried out, but the battery voltage cannot exceed the overcharge voltage to charge, and the charging current is detected at the same time. When the detected current is very small, it means that the battery is close to being fully charged, and it is transferred to the next process. .

(3) At this stage, the battery is float-charged to a constant voltage to maintain the self-discharge of the battery. When the battery voltage drops to a certain level, the first process above will be repeated.

Battery discharge process control:

During the battery discharge process, the battery voltage needs to be monitored. When the voltage is lower than a certain value, the external output should be cut off. When the load capacity is large and the discharge current is large, the battery voltage will drop sharply. By monitoring the battery current It is necessary to adjust the conduction angle of the power switching device, reduce the output current, and increase the protection point of the battery voltage to prevent premature cut-off.

It is worth mentioning that the protection voltage values at each stage of the battery are provided by the battery manufacturer, but the battery voltage is easily affected by temperature and changes, and the battery charging and discharging voltage protection points should be set according to the temperature change. The calculation method of temperature compensation is:

V _b (T)＝[V25+a _t (T-25)] N _c

V _b (T) represents the voltage of the battery at T°C;

V ₂₅ indicates the voltage of the battery at 25°C (standard);

a _t represents the battery temperature coefficient (provided by the manufacturer);

N _c represents the number of batteries;

The maximum power tracking control algorithm is described below:

1. The principle of maximum power point tracking:

The maximum power point tracking is a self-optimization process, and the maximum power point can be tracked by using the "hill climbing method". By detecting the current output voltage and current of the photovoltaic cell, the current output power of the photovoltaic cell is obtained, and then compared with the stored power of the photovoltaic cell at the previous moment, saving the small and saving the large, and then detecting and comparing again. Such non-stop cycle can make the photovoltaic cell work dynamically at the maximum power point. The I-V output characteristic I=f(U) relationship of photovoltaic cells is a single-valued function. Therefore, as long as the output voltage Vpv of photovoltaic cells is maintained, the corresponding maximum power point can be maintained in real time under any solar irradiance and temperature. The corresponding voltage value can guarantee to output its maximum power at any moment.

2. Maximum power point tracking algorithm:

The controller tracks the maximum power point of the photovoltaic cell by controlling the value of Vref. The specific method is to increase or decrease the photovoltaic cell output reference voltage Vref periodically, and the actual output voltage Vpv of the photovoltaic cell tracks Vref through closed-loop control to make the operating point Track the maximum power point.

Assume that the measured current output power of the photovoltaic cell is P(K), the stored memory power at the previous moment is P(k-1), a(k-1) and a(k) are the previous moment and the current moment respectively The voltage increment at time Vref. If it is measured that: P(K)>P(k-1), continue to judge the sign of the value of the increment a(k-1) of Vref at the previous moment. If a(k-1)>0, it means that the system is working on the left side of the maximum power point on the P-V curve, which is close to the maximum power point. Set the current Vref increment a(k)=dV, then Vref(k)=Vref (k-1)+dV. If a(k-1)<0, it means that the system works on the right side of the maximum power point on the P-V curve. In order to be close to the maximum power point, set a(k)=dV, then Vref(k)=Vref(k-1)-dv. On the contrary, if it is measured that: P(K)>P(k-1), the opposite operation is performed similarly. Therefore, the maximum output power point of the photovoltaic cell can be tracked in real time and maintained dynamically.

Fig. 7 provides a functional block diagram of battery charging management and maximum power tracking coordination of the utility model, which has been described in detail in the battery charging process control algorithm.

The solar photovoltaic power station controller of the utility model has the following positive effects:

1. Simple structure, complete functions, easy to expand functions;

2. Combination of digital and analog circuits to give full play to their respective advantages;

3. Modular structure is adopted, which has high reliability and is suitable for mass production;

4. Good operability, able to adapt to poor operating environment.

Claims (4)

1. An independently operating solar photovoltaic power plant controller, characterized in that it consists of a DC-DC conversion main circuit [1], a drive isolation circuit [2], an integrated PWM and protection circuit [3], and a micro-processing control circuit [4] and auxiliary power supply circuit [5]; the DC-DC conversion main circuit [1] is respectively connected with the drive isolation circuit [2], and the back-end output voltage [19] and output current [14] of the DC-DC conversion main circuit [1] ] are respectively connected to the circuit [20] and the circuit [6] of the integrated PWM and protection circuit [3]; the front-end input voltage [18] and input current [17] of the DC-DC conversion main circuit [1] are respectively connected to the micro-processing control circuit [ [a], [b] of the circuit [7] of 4], battery voltage [15] and battery current [16] are respectively connected to [c], [d] of the circuit [7] of the microprocessing control circuit [4]; The driving isolation circuit [2] is respectively connected with the DC-DC conversion main circuit [1] and the auxiliary power supply circuit [5], and the [22] circuit and the [23] circuit of the driving isolation circuit [2] are connected with the DC-DC conversion main circuit [ The circuit [21] of 1] is connected to the circuits [9] and [10] of the auxiliary power supply circuit [5]; the integrated PWM and protection circuit [3] are respectively connected with the drive isolation circuit [2] and the microprocessor control circuit [4] , Auxiliary power supply circuit [5] connection, [24] circuit of integrated PWM and protection circuit [3] is connected to [22] circuit, [23] [circuit and auxiliary power supply circuit [5] of driving isolation circuit [2] 11], the [24] circuit of the integrated PWM and protection circuit [3] is connected to the [26] and [27] circuits of the micro-processing control circuit [4], connected to the PI regulation circuit [20], and the current amplification circuit [6]; The microprocessing control circuit [4] is respectively connected with the auxiliary power supply circuit [5], collecting battery voltage [15], battery current [16], photovoltaic array voltage [17], and photovoltaic array current [18]; the microprocessing control circuit [4 The [25] circuit of ] is connected with the [12] of the auxiliary power supply circuit, and the [25] circuit of the microprocessing control circuit [4] is respectively connected with the A/D conversion limiting circuit [7], the isolated input circuit [26], the isolated output Circuit [27], PC communication circuit, keyboard operation are connected with LCD display circuit and LED display circuit, and circuit [25] I/O output over-discharge control circuit e is connected to storage battery output control circuit [46]. 2. According to claim 1, an independently operating solar photovoltaic power station controller is characterized in that the DC-DC conversion main circuit [1] is composed of two sets of DC-DC conversion circuits [21] with a common negative pole, and the DC-DC conversion The circuit [21] is composed of a power switch tube [28], a diode [29], a filter inductor [30], and a filter capacitor [31]; the output voltage is controlled by driving the power switch tube [28] on and off by the driving waveform and output current, diode [29] freewheeling effect, filter inductor [30] makes the power switch tube work current continuous and intermittent, and filter inductor [31] filters out output ripple. 3. According to claim 1 or 2, an independently operating solar photovoltaic power station controller is characterized in that the drive isolation circuit [2] is composed of isolation amplifier circuits [22] and [23, and the isolation amplifier circuits [22] and [ 23] Connect the driving ends of the power devices of the two main circuits respectively, and use the +15V power supply provided by the optocoupler and the auxiliary power supply for isolation and amplification; the integrated PWM and protection circuit [3] is composed of the integrated PWM circuit [24], the current amplification circuit [ 6], the main circuit output sampling voltage circuit [19] and the voltage regulation circuit [20] are composed; the integrated PWM circuit [24] is provided with +15V power supply voltage by the auxiliary power supply, receives the voltage regulation signal from the microprocessor, and is controlled by the shunt [14] The output current of the main circuit collected by the current amplifier circuit [6] is sent to the integrated PWM circuit to monitor the change of the current, and respond to overcurrent and short circuit; the output voltage of the main circuit is collected by the sampling voltage circuit [19], and adjusted by PI The circuit [20] is sent to the integrated PWM circuit [24], and the power switch tube is regulated through voltage feedback for voltage regulation output. The auxiliary power supply circuit [5] is a flyback switching power supply with multiple outputs, which is composed of voltage stabilizing circuits [9], [10], [11], [12] and the main circuit [13]; the voltage stabilizing circuit [9] , [10], [11], [12] provide high-quality power supply, the voltage stabilizing circuit [9] is connected to the isolation amplifier circuit [22] of the driving isolation circuit [2], and the voltage stabilizing circuit [10] is connected to the driving isolation circuit [ 2] the isolated amplifying circuit [23], the voltage stabilizing circuit [11] is connected to the integrated PWM circuit [24] of the integrated PWM and protection circuit [3], the voltage stabilizing circuit [12] is connected to the microprocessor control circuit [4] The processor and its expansion circuit [25], the main circuit [13] is powered by the battery voltage; the main circuit [13] is composed of a short-circuit and over-current protection circuit [28], a single-input multi-output power frequency transformer circuit [30] ], rectifier circuit [50], [51], [52], [53], filter circuit [54], [55], [56], [57], power switch tube [31], PWM control circuit [29] ]; the overcurrent protection [28] is connected to the battery input, and the filter circuits [54], [55], [56], [57] are respectively connected to the voltage stabilizing circuits [9], [10], [11], [12] , to output the desired DC voltage. 4. A solar photovoltaic power station controller with independent operation according to any one of claims 1 to 3, characterized in that the microprocessor control circuit [4] is composed of a microprocessor and its expansion circuit [25], analog Quantity input limiting circuit [7], analog output PWM isolation filter circuit [27], protection circuit feedback isolation input circuit [26], PC communication serial port, keyboard, and LCD display; The microprocessor of the microprocessor control circuit [4] and its extension circuit [25] are expanded by the main controller Intel chip 4080C196MC, two address expansion bus chips [36], [37], data bus chip [38], and RAM expansion Chip [35] and ROM expansion chip [39], keyboard and LCD display expansion chip [40], A/D conversion circuit [32], D/A conversion circuit [33] (PWMO), LED display expansion chip [41] It also includes input and output I/O circuits [48], [47], and PC communication serial port circuit [45]; D/A conversion circuit [33] (PWMO) is connected to analog output PWM isolation filter circuit [27] ], A/D conversion circuit [32] connects analog input limiter circuit [7], keyboard and LCD display expansion chip [40] connects keyboard [42] and LCD [43], LED display expansion chip [41] connects LED Display [44], the output I/O circuit [48] is connected with the protection circuit feedback isolation input circuit [26], and the 16-bit address bus is connected to the RAM expansion chip by two 8-bit address expansion bus chips [36] and [37] [35] and ROM expansion chip [39], data bus chip [38] and RAM expansion chip [35], ROM expansion chip [39], keyboard and LCD display expansion chip [40], LED display expansion chip [41] respectively connect.

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