CN209675988U - A kind of storage battery charge-discharge control system based on DSP - Google Patents

Abstract

The utility model discloses a DSP-based storage battery charging and discharging control system, which comprises a DSP controller, a PWM rectifier circuit, an IGBT drive circuit, a current detection module, a voltage detection module and a temperature detection module respectively connected to the DSP controller. The AD pins on the controller are respectively connected to the current detection module, voltage detection module and temperature detection module. The PWM rectification circuit is a three-phase voltage type PWM rectification circuit, which converts the alternating current of the city network into direct current. The DSP controller passes the detected charging The current, battery voltage and battery temperature generate a PWM signal to control the on and off of the IGBT drive circuit, and the IGBT drive circuit is used to adjust the charging method of the battery. The beneficial effect of the utility model is that the PWM variable current technology and the energy feedback technology are adopted, the charging process is intelligently adjusted, the power factor of the grid side is improved, the harmonic pollution is reduced, and the charging efficiency of the storage battery is improved at the same time.

Description

A DSP-Based Battery Charging and Discharging Control System

technical field

The utility model relates to the technical field of accumulator charge and discharge, in particular to a DSP-based accumulator charge and discharge control system.

Background technique

The charging and discharging control system is the most critical part of the battery. In the traditional battery charging and discharging methods, most of them use the thyristor converter method, but the thyristor converter method has a low power factor on the grid side and serious harmonic pollution. This design uses PWM converter technology. , can make the system operate at unity power factor, greatly reducing its harmonic pollution to the grid.

Utility model content

The purpose of this utility model is to overcome the above-mentioned technical deficiencies, propose a battery charge and discharge control system based on DSP, and solve the problems mentioned in the above-mentioned background technology.

The technical solution adopted by the utility model provides a DSP-based storage battery charge and discharge control system. The charging process of the storage battery includes trickle charging, constant current charging and constant voltage charging. The DSP-based storage battery charge and discharge control system includes a DSP controller, and a PWM rectifier circuit, an IGBT drive circuit, a current detection module, a voltage detection module and a temperature detection module that are respectively connected to the DSP controller, and the AD pins on the DSP controller are connected to the current detection module, the voltage detection module and the voltage detection module respectively. module and the temperature detection module, the current detection module is used to detect the charging current of the battery, the voltage detection module is used to detect the voltage across the battery, the temperature detection module is used to detect the battery temperature, and the PWM rectifier circuit It is a three-phase voltage type PWM rectifier circuit, which converts the alternating current of the city network into direct current, and the DSP controller generates a PWM signal to control the on and off of the IGBT drive circuit through the detected charging current, battery voltage and battery temperature off, the IGBT drive circuit is used to adjust the charging mode of the storage battery.

The beneficial effect of the utility model is that the PWM variable current technology and the energy feedback technology are adopted, the charging process is intelligently adjusted, the power factor of the grid side is improved, the harmonic pollution is reduced, and the charging efficiency of the storage battery is improved at the same time.

Description of drawings

Fig. 1 is the control schematic diagram of the present utility model;

Fig. 2 is the three-phase controllable rectification circuit in the utility model;

Fig. 3 is the main circuit of battery charging in the utility model;

Fig. 4 is the IGBT driving circuit in the utility model;

Fig. 5 is the voltage detection circuit in the utility model;

Fig. 6 is the current detection circuit in the utility model;

FIG. 7 is a flow chart of battery charging in Embodiment 1 of the present invention.

Detailed ways

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model.

Please refer to Figures 1-7 at the same time. The technical solution adopted by the utility model provides a DSP-based battery charge and discharge control system, including a DSP controller, a PWM rectifier circuit, an IGBT drive circuit, and a current detection circuit respectively connected to the DSP controller. module, voltage detection module and temperature detection module.

The DSP controller adopts TMS320LF2407DSP, the price of TMS320LF2407 chip is cheap, and the running speed is fast. AD, SPI, SCI, CAN, watchdog timer, digital I/O, event manager EVA, EVB and other modules are integrated on the chip. There are 40 general-purpose I/O pins, and most of the pins of the TMS320LF2407DSP chip are multiplexed pins, which can be configured as general-purpose I/O, PWM output, capture CAP pins or external interrupt pins according to specific requirements in the actual application process. feet etc. In this embodiment, the PWM wave is generated by the full comparison unit of the internal event manager of the DSP controller, and the period of the PWM wave can be obtained through the capture unit CAP, and IOPA6~7, IOPB0~3 and IOPE1~4 are selected as the PWM wave output The PWM wave output by these pins has the characteristics of dead zone control. IOPA5 is used as the capture CAP pin to detect the synchronization signal of the power grid. The period of each PWM wave can be obtained by capturing the moment.

Embodiment 1: The above-mentioned DSP-based battery charging and discharging control system monitors the 36V18AH battery pack for charging, wherein the AD pins on the DSP controller are respectively connected to the current detection module, the voltage detection module and the temperature detection module, and IOPA6-7, IOPB0 are selected ～3 and IOPE1～4 are used as PWM wave output pins, and the output PWM wave is sent to the drive circuit of the corresponding IGBT, thereby controlling the corresponding IGBT action, thereby controlling the entire charging process. When charging the battery pack, ADCIN01 is used to detect the voltage at both ends of the battery, ADCIN02 is used to detect the current at both ends of the battery, and ADCIN03 is used to detect the temperature of the battery. When the voltage at both ends of the battery is detected to be less than 31.5V, trickle charging is used. At the same time, the charging current of the trickle charging method is limited within the range of 0.9A-1.8A; when the voltage across the battery is detected to be greater than or equal to 31.5V, the constant current charging method is adopted, and the maximum charging current at this stage cannot exceed 18A; When the voltage at both ends of the battery is charged to 36V, it will enter the constant voltage charging mode. The charging current at this stage is 1.8A. After that, the charging current will gradually decrease. When the detected current is 0.9A, the charging of the battery will stop. At the same time, the charging temperature during the entire charging process cannot exceed 50 degrees. The temperature is detected in real time by the temperature detection module. The temperature detection module uses a temperature sensor DS18B20. The temperature sensor DS18B20 can measure the temperature of the battery, and convert the measured temperature into power to the battery. DSP controller.

As shown in Figure 1, eab is the line voltage on the AC side, ia and ib are the phase currents of phase A and phase B on the AC side, respectively, Idc is the charging current, and Udc is the charging voltage. In order to achieve the purpose of energy saving, a freewheeling diode is connected in series between the charging and discharging circuit. The energy released by the storage battery is fed back to the charging circuit side through the freewheeling diode, so as to improve the utilization rate of energy. Since the city network cannot directly charge the storage battery, this design uses a three-phase voltage PWM rectifier circuit to convert the alternating current of the city network into direct current. The core component of the rectifier circuit is a fully-controlled voltage-driven power switch element IGBT, whose on and off are controlled by PWM waves generated by DSP. However, the PWM wave generated by the DSP is not enough to directly drive the IGBT. An IGBT drive circuit must be added between the DSP and the IGBT. The PWM signal output by the DSP controls the opening and closing of the IGBT, thereby realizing the function of pulse charging the battery. Pulse charging can well reduce the gas released from the battery and improve the energy waste caused by polarization. At the same time, this method can also play a role in desulfurization, thereby improving the charging efficiency of the battery and repairing the battery. Extend battery life. Parameters such as charging voltage, current and battery temperature can be detected through the corresponding analog-to-digital conversion interface of DSP.

This technical solution converts the 220V AC power of the city network into DC power to charge the battery through a three-phase controllable rectification circuit. The three-phase controllable rectification circuit is shown in Figure 2. The current and voltage of the battery are controlled by a bidirectional buck-boost circuit, which is the key to complete the bidirectional flow of energy during the charging and discharging process. The battery voltage, current and temperature are sent to the ADC channel of the DSP through related circuits to realize fast pulse charging of the battery. When controlling the current and voltage of the battery, the step-up and step-down work are used alternately. In order to reduce the high-frequency switching loss, a freewheeling diode is connected to both ends of the switch tube IGBT. The main circuit of battery charging is shown in Figure 3. The DSP controller detects the charging current in real time through the current detection module, detects the battery voltage in real time through the voltage detection module, and detects the battery temperature in real time through the temperature detection module, and judges charging according to the corresponding real-time voltage value. Phase, and generate the corresponding PWM wave, control the corresponding IGBT through the PWM signal, so that the IGBT is turned on and off normally. Wave.

Figure 4 is the IGBT driving circuit in the utility model, the PWM signal voltage generated by the DSP controller TMS320LF2407DSP is 0~3.3V, and the driving voltage of the IGBT is -5~15V, so the PWM signal generated by the DSP cannot be used to directly drive the IGBT , so it is necessary to isolate and amplify the PWM signal output by the DSP by driving the isolation amplifier circuit, so that the output PWM signal can control the normal on and off of the IGBT. The isolation amplifier circuit adopts HCPL-316J.

Fig. 5 is the voltage detection circuit in the utility model, the voltage detection circuit collects the voltage data through the voltage transformer JLBV300FA, and filters through the RC filter circuit, the voltage follower in the circuit acts as isolation, and the voltage regulator tube in the circuit acts as Limiting function (the signal received by the DSP controller cannot exceed 3.3V), the collected voltage signal is sent to the ADCIN01 interface of the DSP controller, and the DSP controller compares the detected value with the set value to flexibly control the charging process of the battery.

Figure 6 is the current detection circuit in the utility model, the current detection circuit converts the charging current collected by the CHB-25NP Hall current sensor into a voltage through the sampling resistor R2, and then passes through the second-order filter circuit. This circuit is composed of R2, The active filter circuit composed of R3, R4, C5 and operational amplifier LM358 (active filter can make the signal greater than the cut-off frequency attenuated faster) and R5, C7 constitutes, the collected signal is filtered, and finally passed through the regulator tube D11 (plays the role of limiting, because the signal received by this DSP cannot exceed 3.3V) is sent to the ADCIN02 interface of the DSP controller, and the DSP controller compares the detected value with the set value, combined with the voltage detected by the voltage detection circuit value, and flexibly control the charging process of the battery together.

As shown in Figure 7, taking a 36V10Ah battery pack as an example, its operating voltage range is generally between 31.5 and 41V. In the figure, V is the voltage of the battery pack, and I is the current.

Among the above technical solutions, the working principle of the utility model: during the user’s use, the charging and discharging of the battery adopts a three-stage pulse charging and discharging control strategy, that is, trickle charging first, then constant current charging, and finally constant voltage charging. In the charging process, in order to prevent the battery from being damaged during the charging process, the maximum output voltage of the battery must be lower than the maximum limit voltage during constant current charging; while in the constant voltage charging stage, it must be ensured that the output current cannot exceed the maximum current of the battery limit. In order to ensure that the automatic conversion can be better completed in different stages, according to the collected signals such as the terminal voltage, current and temperature of the battery pack, a corresponding PWM wave control signal is generated to drive the IGBT to perform corresponding switching actions, and to improve the charging and discharging efficiency of the battery pack. And prevent overcharging, over-discharging and other phenomena.

Compared with the prior art, the utility model has the beneficial effects: it adopts PWM conversion technology and energy feedback technology, intelligently adjusts the charging process, improves the power factor of the grid side, reduces harmonic pollution, and improves the charging efficiency of the storage battery at the same time.

The specific embodiments of the utility model described above do not constitute a limitation to the protection scope of the utility model. Any other corresponding changes and deformations made according to the technical concept of the utility model shall be included in the protection scope of the claims of the utility model.

Claims (5)

1. a kind of storage battery charge-discharge control system based on DSP, the charging process of battery includes trickle charge, constant-current charge And constant-voltage charge characterized by comprising dsp controller and the PWM rectification circuit being connect respectively with dsp controller, IGBT drive circuit, current detection module, voltage detection module and temperature detecting module, the AD pin on the dsp controller It is separately connected the current detection module, the voltage detection module and the temperature detecting module, the current detection module For detecting the charging current of battery, the voltage detection module is for detecting battery both end voltage, the temperature detecting module For detecting battery temperature, the PWM rectification circuit is three-phase voltage type PWM rectification circuit, and the alternating current that city is netted is become straight Galvanic electricity, the dsp controller pass through charging current, cell voltage and the battery temperature detected, generate described in pwm signal control The turn-on and turn-off of IGBT drive circuit, the IGBT drive circuit are used to adjust the charging modes of battery.

2. a kind of storage battery charge-discharge control system based on DSP as described in claim 1, which is characterized in that the DSP control Device processed uses TMS320LF2407.

3. a kind of storage battery charge-discharge control system based on DSP as described in claim 1, which is characterized in that the electric current Detection module uses the Hall current sensor of CHB-25NP.

4. a kind of storage battery charge-discharge control system based on DSP as described in claim 1, which is characterized in that the voltage Detection module uses the voltage transformer of JLBV300 FA.

5. a kind of storage battery charge-discharge control system based on DSP as described in claim 1, which is characterized in that the temperature Detection module uses temperature sensor DS18B20.