A bidirectional power supply control system and method with a wide voltage range

Abstract

The present invention provides a bidirectional power supply control system and method with a wide voltage range in the field of power control technology, the system includes: an AC power distribution module; an AC-DC converter connected to the AC power distribution module; an energy bidirectional conversion module connected to the AC-DC converter; a host computer connected to the energy bidirectional conversion module; the energy bidirectional conversion module includes: a first DC-DC converter connected to the AC-DC converter; a second DC-DC converter connected to the AC-DC converter; a current sensor connected to the first DC-DC converter; a power output unit connected to the current sensor and the second DC-DC converter; a voltage sensor connected in parallel at both ends of the power output unit and the load; a temperature sensor; a signal processing unit connected to the current sensor, the voltage sensor, and the temperature sensor; a DSP chip connected to the first DC-DC converter, the second DC-DC converter, the signal processing unit, and the host computer. The advantages of the present invention are: the voltage variation range and operation stability of the power control system are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power control, and in particular to a bidirectional power supply control system and method with a wide voltage range. Background Art

[0002] With the rapid development of society, people's living standards are constantly improving, and people's demand for energy is increasing. In the structural changes in the development and utilization of new energy, energy conservation and consumption reduction will become the focus of energy development, making energy bidirectional flow conversion equipment widely used and promoted. With the continuous development and innovation of battery materials, battery energy density and charge and discharge cycle performance have been greatly improved. Power batteries, one of the core components of new energy vehicles, are developing rapidly with the rise of the new energy industry, further promoting the development and growth of energy bidirectional flow conversion equipment.

[0003] A large number of battery packs require strict performance evaluation in multiple links from formation to delivery of finished products. The charging and discharging operation of the battery pack is the most basic testing and evaluation link. The bidirectional energy flow conversion equipment provides practical technical support for saving energy, reducing costs and improving production environment conditions.

[0004] However, the conventional energy bidirectional flow conversion device adopts two DC-DC converters in anti-parallel connection or H-type full-bridge structure, which has the following disadvantages:

[0005] 1. The battery packs produced by battery manufacturers may need to cope with application scenarios ranging from single-string batteries for mobile phones, several strings of batteries for tablet computers, more than a dozen strings of batteries for power tools, and dozens of strings of batteries for electric vehicles. The nominal voltage of the battery pack ranges from 3.6V to 400V, or even higher; the traditional energy bidirectional flow conversion equipment has a narrow conversion output voltage range, or can even only output a fixed voltage, and the application scenario is single. When dealing with battery pack detection scenarios, it is difficult to achieve the needs of full-range voltage detection and maintenance of battery packs. Often, multiple detection equipment or integrated large-scale detection equipment is required to detect battery packs of different voltages, which is inconvenient to use and not conducive to debugging and production.

[0006] 2. When directly using relays or MOS tubes to output power, the mechanical jitter generated during the relay switching process will cause impact on the circuit. Turning off the relay under load may also cause damage to the relay, seriously affecting its service life. When using MOS tubes to output power, complete electrical isolation cannot be achieved, which will cause unnecessary interference to other related circuits.

[0007] Therefore, how to provide a bidirectional power control system and method with a wide voltage range to improve the voltage variation range and operation stability of the power control system has become an urgent problem to be solved. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a bidirectional power supply control system and method with a wide voltage range, so as to improve the voltage variation range and operation stability of the power supply control system.

[0009] In a first aspect, the present invention provides a bidirectional power supply control system with a wide voltage range, comprising:

[0010] AC power distribution module;

[0011] An AC-DC converter connected to the AC power distribution module;

[0012] An energy bidirectional conversion module connected to the AC-DC converter;

[0013] A host computer connected to the energy bidirectional conversion module;

[0014] The energy bidirectional conversion module comprises:

[0015] A first DC-DC converter, one end of which is connected to the AC-DC converter;

[0016] A second DC-DC converter, one end of which is connected to the AC-DC converter;

[0017] a current sensor, one end of which is connected to the other end of the first DC-DC converter;

[0018] A power output unit, connected to the current sensor and the other end of the second DC-DC converter respectively;

[0019] A voltage sensor is connected in parallel between the power output unit and the load;

[0020] Temperature sensor;

[0021] A signal processing unit, connected to the current sensor, the voltage sensor and the temperature sensor respectively;

[0022] The DSP chip is connected to the first DC-DC converter, the second DC-DC converter, the power output unit, the signal processing unit and the host computer respectively.

[0023] Further, the first DC-DC converter includes a capacitor Ci1, a capacitor Co1, a resistor R1, a resistor R2, an inductor L1, a MOS transistor V1 and a MOS transistor V2;

[0024] The positive electrode of the capacitor Ci1 is connected to the positive electrode of the AC-DC converter and the pin 2 of the MOS tube V1, and the negative electrode is connected to the negative electrode of the AC-DC converter, the resistor R2, the pin 3 of the MOS tube V2, the negative electrode of the capacitor Co1 and the power output unit; the pin 1 of the MOS tube V1 is connected to the resistor R1 and the DSP chip, and the pin 3 is connected to the resistor R1, the inductor L1 and the pin 2 of the MOS tube V2; the pin 1 of the MOS tube V2 is connected to the resistor R2 and the DSP chip; the inductor L1 is connected to the positive electrode of the capacitor Co1 and the current sensor.

[0025] Further, the second DC-DC converter includes a capacitor Ci2, a capacitor Co2, a resistor R3, a resistor R4, an inductor L2, a MOS transistor V3 and a MOS transistor V4;

[0026] The positive electrode of the capacitor Ci2 is connected to the positive electrode of the AC-DC converter and the pin 2 of the MOS tube V3, and the negative electrode is connected to the negative electrode of the AC-DC converter, the resistor R4, the pin 3 of the MOS tube V4, the negative electrode of the capacitor Co2 and the power output unit; the pin 1 of the MOS tube V3 is connected to the resistor R3 and the DSP chip, and the pin 3 is connected to the resistor R3, the inductor L2 and the pin 2 of the MOS tube V4; the pin 1 of the MOS tube V4 is connected to the resistor R4 and the DSP chip; the inductor L2 is connected to the positive electrode of the capacitor Co2 and the power output unit.

[0027] Further, the signal processing unit includes a high-precision AD chip U2, a capacitor C1, a resistor R5, a resistor R6, a resistor R7, a resistor R8 and an operational amplifier U3;

[0028] One end of the high-precision AD chip U2 is connected to the DSP chip, and the other end is connected to the resistor R5 and the capacitor C1; pin 2 of the operational amplifier U3 is connected to the resistor R7 and the resistor R6, pin 3 is connected to the resistor R8, and pin 6 is connected to the resistor R5 and the resistor R6; the capacitor C1 and the resistor R8 are both grounded; the resistor R7 is connected to the current sensor, the voltage sensor and the temperature sensor.

[0029] Further, the power output unit includes a capacitor Co3, a MOS tube V5, a MOS tube V6, a double-pole double-throw switch K1 and a double-pole double-throw switch K3;

[0030] The positive electrode of the capacitor Co3 is connected to the current sensor, the voltage sensor and the pin 2 of the MOS tube V5, and the negative electrode is connected to the pin 2 of the double-pole double-throw switch K3, the pin 2 of the double-pole double-throw switch K1 and the voltage sensor; the pin 1 of the double-pole double-throw switch K3 is connected to the first DC-DC converter, and the pins 3 and 4 are connected to the second DC-DC converter; the pin 2 of the MOS tube V6 is connected to the pin 3 of the MOS tube V5, and the pin 3 is connected to the pin 1 of the double-pole double-throw switch K1; the pins 3 and 4 of the double-pole double-throw switch K1 are connected to the voltage sensor;

[0031] Pin 1 of the MOS tube V5, pin 1 of the MOS tube V6, pin 1 of the double-pole double-throw switch K1, and pin 5 of the double-pole double-throw switch K3 are all connected to the DSP chip.

[0032] Furthermore, the double-pole double-throw switch K1 and the double-pole double-throw switch K3 are both electrically controlled switches.

[0033] Furthermore, the voltage sensor is a four-wire voltage sensor.

[0034] In a second aspect, the present invention provides a bidirectional power supply control method with a wide voltage range, comprising the following steps:

[0035] Step S10: The host computer obtains the voltage Vset required by the load set by the user and sends it to the DSP chip;

[0036] Step S20, the host computer first turns on the double-pole double-throw switch K1 through the DSP chip, and then turns on the MOS tube V5 and the MOS tube V6;

[0037] Step S30: the AC power distribution module inputs the AC power of the power grid into the AC-DC converter, converts the AC power into DC power, and then inputs the DC power into the energy bidirectional conversion module;

[0038] Step S40, the DSP chip controls the working state of the power output unit based on the maximum output voltage Vin, the maximum duty cycle Dmax, the minimum duty cycle Dmin and the voltage Vset of the first DC-DC converter and the second DC-DC converter to output a wide voltage range;

[0039] Step S50: The signal processing unit obtains detection data through the current sensor, the voltage sensor and the temperature sensor, amplifies, filters and samples the detection data, and then inputs the data into the DSP chip;

[0040] Step S60: the host computer obtains the detection parameters through the DSP chip, and dynamically adjusts the working state of the energy bidirectional conversion module based on the detection parameters;

[0041] Step S70: After the detection is completed, the host computer first disconnects the MOS tube V5 and the MOS tube V6 through the DSP chip, and then disconnects the double-pole double-throw switch K1.

[0042] Furthermore, the step S40 is specifically as follows:

[0043] The DSP chip obtains the maximum output voltage Vin, the maximum duty cycle Dmax, the minimum duty cycle Dmin, and the voltage Vset of the first DC-DC converter and the second DC-DC converter;

[0044] When Vset>(Dmax-Dmin)*Vin, the DSP chip controls the first DC-DC converter and the second DC-DC converter to add voltage and output voltage through the double-pole double-throw switch K3, so that the first DC-DC converter and the second DC-DC converter output a voltage of 0.5Vset respectively;

[0045] When Vset<(Dmax-Dmin)*Vin, the DSP chip controls the first DC-DC converter and the second DC-DC converter to perform voltage subtraction output through the double-pole double-throw switch K3, so that the duty cycle of the first DC-DC converter or the second DC-DC converter is Dmin, and the duty cycle of the other is Vset / Vin+Dmin. When the duty cycles of the first DC-DC converter and the second DC-DC converter are close, zero voltage charging and discharging are performed;

[0046] When Vset is less than 0, the DSP chip controls the first DC-DC converter and the second DC-DC converter to perform voltage subtraction output through the double-pole double-throw switch K3, so that the duty cycle values ​​of the first DC-DC converter and the second DC-DC converter are different, so that the output negative voltage has a value range of (Dmin-Dmax)*Vin to 0.

[0047] Furthermore, in step S50, the detection data includes current data, voltage data and temperature data.

[0048] The advantages of the present invention are:

[0049] 1. By setting the first DC-DC converter and the second DC-DC converter with the same structure as the upper and lower bridge arms of the energy bidirectional conversion module for power output, and setting a double-pole double-throw switch K3 for controlling the working mode (voltage addition output / voltage subtraction output) of the first DC-DC converter and the second DC-DC converter, combined with the maximum output voltage Vin, the maximum duty cycle Dmax, the minimum duty cycle Dmin and the voltage Vset of the DC-DC converter, the voltage range of the power control system output is (Dmin-Dmax)*Vin to 2*(Dmax-Dmin)*Vin, covering the positive voltage output and the negative voltage output, which greatly improves the voltage variation range of the power control system.

[0050] 2. By setting the MOS tube V5, MOS tube V6 and double-pole double-throw switch K1 in series, when loading power, the double-pole double-throw switch K1 is turned on first, and then the MOS tube V5 and MOS tube V6 are turned on, thereby reducing the impact of the circuit connection on the load (battery pack to be detected) during the process of turning on the double-pole double-throw switch K1; when turning off the power, the MOS tube V5 and MOS tube V6 are disconnected first, and when the current of the double-pole double-throw switch K1 is almost 0, the double-pole double-throw switch K1 is disconnected, thereby avoiding damage to the device caused by the double-pole double-throw switch K1 being turned off with load, thereby greatly improving the operation stability of the power control system.

[0051] 3. By setting the voltage sensor as a four-wire voltage sensor, the voltages of the power output unit and the load are collected separately, thereby greatly improving the voltage control accuracy.

[0052] 4. When Vset is less than (Dmax-Dmin)*Vin, the DSP chip controls the first DC-DC converter and the second DC-DC converter to perform voltage subtraction output through the double-pole double-throw switch K3, so that the duty cycle of one DC-DC converter is Dmin and the duty cycle of the other is Vset / Vin+Dmin. When the duty cycles of the two DC-DC converters are close, zero-voltage charging and discharging are performed to make the battery pack charge more saturated and discharge more thoroughly, so as to improve the accuracy of battery pack detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The present invention will be further described below in conjunction with embodiments with reference to the accompanying drawings.

[0054] Figure 1 The invention discloses a circuit principle block diagram of a bidirectional power supply control system with a wide voltage range.

[0055] Figure 2 It is a circuit principle block diagram of the energy bidirectional conversion module of the present invention.

[0056] Figure 3It is a circuit diagram of the energy bidirectional conversion module of the present invention.

[0057] Figure 4 is a circuit diagram of the signal processing unit of the present invention.

[0058] Figure 5 The present invention is a flow chart of a bidirectional power supply control method with a wide voltage range.

[0059] Marking Description:

[0060] 100-a bidirectional power supply control system with a wide voltage range, 1-AC power distribution module, 2-AC-DC converter, 3-energy bidirectional conversion module, 4-host computer, 31-first DC-DC converter, 32-second DC-DC converter, 33-current sensor, 34-power output unit, 35-voltage sensor, 36-temperature sensor, 37-signal processing unit, 38-DSP chip. DETAILED DESCRIPTION

[0061] The technical solution in the embodiment of the present application has the following general idea: by setting two DC-DC converters 31 / 32 of the same structure as the upper and lower bridge arms of the energy bidirectional conversion module 3 for power output, and setting a double-pole double-throw switch K3 for controlling the working mode (voltage addition output / voltage subtraction output) of the two DC-DC converters 31 / 32, the voltage range output by the power control system 100 is made to be (Dmin-Dmax)*Vin to 2(Dmax-Dmin)*Vin; by setting the MOS tube V5, the MOS tube V6 and the double-pole double-throw switch K1 in series, by controlling the on-off sequence of the MOS tube V5, the MOS tube V6 and the double-pole double-throw switch K1 to reduce the impact, the voltage variation range and the operation stability of the power control system 100 are finally improved.

[0062] Please refer to Figures 1 to 5 As shown, a preferred embodiment of a bidirectional power supply control system 100 with a wide voltage range of the present invention includes:

[0063] The AC power distribution module 1 is used to control the distribution of electric energy of the 220V / 380V three-phase AC power of the power grid, and to perform power-off protection when overload, short circuit or leakage occurs in the power control system 100;

[0064] The AC-DC converter 2 is connected to the AC power distribution module 1 and is used to rectify the AC power input by the AC power distribution module 1 to supply a stable DC voltage. During discharge, the energy transmitted by the energy bidirectional conversion module 3 is inverted and transmitted to the AC power distribution module 1 and then to the power grid.

[0065] The energy bidirectional conversion module 3 is connected to the AC-DC converter 2 and is used to control the output power, voltage and current according to the instructions of the host computer 4, and collect current data, voltage data and temperature data to the host computer 4 as a control basis, that is, for power loading and power monitoring. When an abnormal situation occurs, the power output is immediately shut down and the protection mechanism is activated;

[0066] A host computer 4, connected to the energy bidirectional conversion module 3, for controlling the operation of the power supply control system 100;

[0067] The energy bidirectional conversion module 3 comprises:

[0068] A first DC-DC converter 31, one end of which is connected to the AC-DC converter 2;

[0069] A second DC-DC converter 32, one end of which is connected to the AC-DC converter 2; the first DC-DC converter 31 and the second DC-DC converter 32 have the same structure and are used to control parameters such as voltage, current, and power to achieve bidirectional flow of power input and output;

[0070] A current sensor 33, one end of which is connected to the other end of the first DC-DC converter 31; the current sensor 33 is a Hall current sensor, which is used to proportionally attenuate the current signal of the first DC-DC converter 31 and convert it into a voltage signal;

[0071] A power output unit 34 is connected to the first DC-DC converter 31, the current sensor 33 and the other end of the second DC-DC converter 32 respectively;

[0072] A voltage sensor 35 is connected in parallel between the power output unit 34 and a load (not shown);

[0073] Temperature sensor 36;

[0074] A signal processing unit 37 connected to the current sensor 33, the voltage sensor 35 and the temperature sensor 36 respectively;

[0075] The DSP chip 38 is connected to the first DC-DC converter 31 , the second DC-DC converter 32 , the power output unit 34 , the signal processing unit 37 and the host computer 4 respectively.

[0076] The DSP chip 38 has the following functions: 1. Communication function: based on SPI, RS232, CAN, I2C, RSA85, Ethernet and other communication interfaces, it is used to communicate with peripheral chips and the host computer 4; 2. Power loading function: PWM output, used to control the PWM duty cycle output of the first DC-DC converter 31 and the second DC-DC converter 32, realize power conversion and bidirectional power flow through the PID control algorithm, control the reasonable on and off of the double-pole double-throw switch K3, so as to realize voltage, current, power conversion, and current and power bidirectional flow; 3. Sampling function: A / D sampling, I / O bit number sampling, voltage, current And sampling of parameters such as temperature, abnormal working burst signal feedback, etc., and reporting detection data to the host computer 4; 4. Control output: used to control the operation of the first DC-DC converter 31 and the second DC-DC converter 32; 5. Protection function: real-time monitoring of the protection signal of the signal processing unit 37, once the protection signal is triggered, immediately turn off the PWM output and disconnect each switch to ensure the safety of the power control system 100; 6. Display and buttons, storage: the operator can configure the working parameters of the energy bidirectional conversion module 3 through the human-machine interface such as the display screen, indicator lights and buttons, and store the power, voltage and current curve data for a certain period of time for easy query.

[0077] The first DC-DC converter 31 includes a capacitor Ci1, a capacitor Co1, a resistor R1, a resistor R2, an inductor L1, a MOS transistor V1 and a MOS transistor V2;

[0078] The positive electrode of the capacitor Ci1 is connected to the positive electrode of the AC-DC converter 2 and the pin 2 of the MOS tube V1, and the negative electrode is connected to the negative electrode of the AC-DC converter 2, the resistor R2, the pin 3 of the MOS tube V2, the negative electrode of the capacitor Co1 and the power output unit 34; the pin 1 of the MOS tube V1 is connected to the resistor R1 and the DSP chip 38, and the pin 3 is connected to the resistor R1, the inductor L1 and the pin 2 of the MOS tube V2; the pin 1 of the MOS tube V2 is connected to the resistor R2 and the DSP chip 38; the inductor L1 is connected to the positive electrode of the capacitor Co1 and the current sensor 33.

[0079] The second DC-DC converter 32 includes a capacitor Ci2, a capacitor Co2, a resistor R3, a resistor R4, an inductor L2, a MOS transistor V3 and a MOS transistor V4;

[0080] The positive electrode of the capacitor Ci2 is connected to the positive electrode of the AC-DC converter 2 and the pin 2 of the MOS tube V3, and the negative electrode is connected to the negative electrode of the AC-DC converter 2, the resistor R4, the pin 3 of the MOS tube V4, the negative electrode of the capacitor Co2 and the power output unit 34; the pin 1 of the MOS tube V3 is connected to the resistor R3 and the DSP chip 38, and the pin 3 is connected to the resistor R3, the inductor L2 and the pin 2 of the MOS tube V4; the pin 1 of the MOS tube V4 is connected to the resistor R4 and the DSP chip 38; the inductor L2 is connected to the positive electrode of the capacitor Co2 and the power output unit 34.

[0081] The signal processing unit 37 includes a high-precision AD chip U2, a capacitor C1, a resistor R5, a resistor R6, a resistor R7, a resistor R8 and an operational amplifier U3;

[0082] One end of the high-precision AD chip U2 is connected to the DSP chip 38, and the other end is connected to the resistor R5 and the capacitor C1; pin 2 of the operational amplifier U3 is connected to the resistor R7 and the resistor R6, pin 3 is connected to the resistor R8, and pin 6 is connected to the resistor R5 and the resistor R6; the capacitor C1 and the resistor R8 are both grounded; the resistor R7 is connected to the current sensor 33, the voltage sensor 35 and the temperature sensor 36.

[0083] The power output unit 34 includes a capacitor Co3, a MOS tube V5, a MOS tube V6, a double-pole double-throw switch K1 and a double-pole double-throw switch K3; the MOS tube V5 and the MOS tube V6 are connected in reverse series, and the output voltages are added or subtracted through the double-pole double-throw switch K3;

[0084] The positive electrode of the capacitor Co3 is connected to the current sensor 33, the voltage sensor 35 and the pin 2 of the MOS tube V5, and the negative electrode is connected to the pin 2 of the double-pole double-throw switch K3, the pin 2 of the double-pole double-throw switch K1 and the voltage sensor 35; the pin 1 of the double-pole double-throw switch K3 is connected to the first DC-DC converter 31, and the pins 3 and 4 are connected to the second DC-DC converter 32; the pin 2 of the MOS tube V6 is connected to the pin 3 of the MOS tube V5, and the pin 3 is connected to the pin 1 of the double-pole double-throw switch K1; the pins 3 and 4 of the double-pole double-throw switch K1 are connected to the voltage sensor 35;

[0085] Pin 1 of the MOS tube V5 , pin 1 of the MOS tube V6 , pin 1 of the double-pole double-throw switch K1 , and pin 5 of the double-pole double-throw switch K3 are all connected to the DSP chip 38 .

[0086] The double-pole double-throw switch K1 and the double-pole double-throw switch K3 are both electrically controlled switches.

[0087] The voltage sensor 35 is a four-wire voltage sensor, which is used to ensure the voltage sampling and measurement accuracy.

[0088] A preferred embodiment of a bidirectional power supply control method with a wide voltage range of the present invention comprises the following steps:

[0089] Step S10: The host computer obtains the voltage Vset required by the load set by the user and sends it to the DSP chip;

[0090] Step S20, the host computer first turns on the double-pole double-throw switch K1 through the DSP chip, and then turns on the MOS tube V5 and the MOS tube V6;

[0091] Step S30: the AC power distribution module inputs the AC power of the power grid into the AC-DC converter, converts the AC power into DC power, and then inputs the DC power into the energy bidirectional conversion module;

[0092] Step S40, the DSP chip controls the working state of the power output unit based on the maximum output voltage Vin, the maximum duty cycle Dmax, the minimum duty cycle Dmin and the voltage Vset of the first DC-DC converter and the second DC-DC converter to output a wide voltage range;

[0093] Step S50: The signal processing unit obtains detection data through the current sensor, the voltage sensor and the temperature sensor, amplifies, filters and samples the detection data, and then inputs the data into the DSP chip;

[0094] Step S60: the host computer obtains and saves the detection parameters through the DSP chip, and dynamically adjusts the working state of the energy bidirectional conversion module based on the detection parameters;

[0095] Step S70: After the detection is completed, the host computer first disconnects the MOS tube V5 and the MOS tube V6 through the DSP chip, and then disconnects the double-pole double-throw switch K1.

[0096] The step S40 is specifically as follows:

[0097] The DSP chip obtains the maximum output voltage Vin, the maximum duty cycle Dmax, the minimum duty cycle Dmin, and the voltage Vset of the first DC-DC converter and the second DC-DC converter;

[0098] When Vset>(Dmax-Dmin)*Vin, the maximum allowable output voltage of a single DC-DC converter is exceeded. The DSP chip controls the first DC-DC converter and the second DC-DC converter to add voltage and output voltage through the double-pole double-throw switch K3, so that the first DC-DC converter and the second DC-DC converter output a voltage of 0.5Vset respectively. When the first DC-DC converter and the second DC-DC converter work at the same time, the theoretical maximum allowable output voltage is 2*(Dmax-Dmin)*Vin.

[0099] When Vset<(Dmax-Dmin)*Vin, the DSP chip controls the first DC-DC converter and the second DC-DC converter to perform voltage subtraction output through the double-pole double-throw switch K3, so that the duty cycle of the first DC-DC converter or the second DC-DC converter is Dmin, and the duty cycle of the other is Vset / Vin+Dmin. When the duty cycles of the first DC-DC converter and the second DC-DC converter are close, zero voltage charging and discharging are performed;

[0100] When Vset is less than 0, the DSP chip controls the first DC-DC converter and the second DC-DC converter to perform voltage subtraction output through the double-pole double-throw switch K3, so that the duty cycle values ​​of the first DC-DC converter and the second DC-DC converter are different, so that the output negative voltage ranges from (Dmin-Dmax)*Vin to 0. The voltage output range of the energy bidirectional conversion module is (Dmin-Dmax)*Vin to 2*(Dmax-Dmin)*Vin.

[0101] In the step S50, the detection data includes current data, voltage data and temperature data.

[0102] In step S60, the working state of the dynamic adjustment energy bidirectional conversion module is further described as follows:

[0103] When energy flows in the forward direction, the first DC-DC converter and the second DC-DC converter of the energy bidirectional conversion module are forward voltage drops and work in BUCK mode. Assuming the input voltage is Ui, the output voltage is Uo, and the duty cycle of the PWM signal sent by the DSP chip is D, then Uo=Ui*D; when energy flows out, the DC-DC converter reversely boosts the voltage and works in BOOST mode, Ui=Uo*(1-D).

[0104] When the host computer sends instructions to the energy bidirectional conversion module, the DSP chip collects and calculates the load port voltage UL and the front-end voltage Ui of the energy bidirectional conversion module, calculates the initial duty cycle value D according to the formula D=UL / Ui, and drives the two DC-DC converters to work and convert the required energy output.

[0105] Based on the parameter setting values ​​and collected values, the DSP chip uses current as the inner loop and voltage as the outer loop. It calculates the duty cycle of the two DC-DC converters in real time at a certain frequency through negative feedback using the PID algorithm, and controls the PWM signal output, thereby achieving constant output of voltage, current and power.

[0106] When the voltage at the output end of the energy bidirectional conversion module is higher than the configured nominal voltage, the energy bidirectional conversion module will automatically enter the reverse boost working state, and work in BOOST mode to stabilize the output working voltage. The reverse output power is then inverted and fed back to the power grid through the AC-DC converter. The host computer can also issue instructions to allow the energy bidirectional conversion module and the DC-DC converter to work in the inverter boost working state.

[0107] In summary, the advantages of the present invention are:

[0108] 1. By setting the first DC-DC converter and the second DC-DC converter with the same structure as the upper and lower bridge arms of the energy bidirectional conversion module for power output, and setting a double-pole double-throw switch K3 for controlling the working mode (voltage addition output / voltage subtraction output) of the first DC-DC converter and the second DC-DC converter, combined with the maximum output voltage Vin, the maximum duty cycle Dmax, the minimum duty cycle Dmin and the voltage Vset of the DC-DC converter, the voltage range of the power control system output is (Dmin-Dmax)*Vin to 2*(Dmax-Dmin)*Vin, covering the positive voltage output and the negative voltage output, which greatly improves the voltage variation range of the power control system.

[0109] 2. By setting the MOS tube V5, MOS tube V6 and double-pole double-throw switch K1 in series, when loading power, the double-pole double-throw switch K1 is turned on first, and then the MOS tube V5 and MOS tube V6 are turned on, thereby reducing the impact of the circuit connection on the load (battery pack to be detected) during the process of turning on the double-pole double-throw switch K1; when turning off the power, the MOS tube V5 and MOS tube V6 are disconnected first, and when the current of the double-pole double-throw switch K1 is almost 0, the double-pole double-throw switch K1 is disconnected, thereby avoiding damage to the device caused by the double-pole double-throw switch K1 being turned off with load, thereby greatly improving the operation stability of the power control system.

[0110] 3. By setting the voltage sensor as a four-wire voltage sensor, the voltages of the power output unit and the load are collected separately, thereby greatly improving the voltage control accuracy.

[0111] 4. When Vset is less than (Dmax-Dmin)*Vin, the DSP chip controls the first DC-DC converter and the second DC-DC converter to perform voltage subtraction output through the double-pole double-throw switch K3, so that the duty cycle of one DC-DC converter is Dmin and the duty cycle of the other is Vset / Vin+Dmin. When the duty cycles of the two DC-DC converters are close, zero-voltage charging and discharging are performed to make the battery pack charge more saturated and discharge more thoroughly, so as to improve the accuracy of battery pack detection.

[0112] Although the specific implementation modes of the present invention are described above, those skilled in the art should understand that the specific implementation modes described are only illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A bidirectional power supply control method with a wide voltage range, characterized in that: The method requires the use of a bidirectional power supply control system with a wide voltage range, comprising the following steps: Step S10: The host computer obtains the voltage Vset required by the load set by the user and sends it to the DSP chip; Step S20, the host computer first turns on the double-pole double-throw switch K1 through the DSP chip, and then turns on the MOS tube V5 and the MOS tube V6; Step S30: the AC power distribution module inputs the AC power of the power grid into the AC-DC converter, converts the AC power into DC power, and then inputs the DC power into the energy bidirectional conversion module; Step S40, the DSP chip controls the working state of the power output unit based on the maximum output voltage Vin, the maximum duty cycle Dmax, the minimum duty cycle Dmin and the voltage Vset of the first DC-DC converter and the second DC-DC converter to output a wide voltage range; Step S50: The signal processing unit obtains detection data through the current sensor, the voltage sensor and the temperature sensor, and amplifies, filters and samples the detection data before inputting it into the DSP chip; the detection data includes current data, voltage data and temperature data; Step S60: the host computer obtains the detection data through the DSP chip, and dynamically adjusts the working state of the energy bidirectional conversion module based on the detection data; Step S70: After the detection is completed, the host computer first disconnects the MOS tube V5 and the MOS tube V6 through the DSP chip, and then disconnects the double-pole double-throw switch K1; The step S40 is specifically as follows: The DSP chip obtains the maximum output voltage Vin, the maximum duty cycle Dmax, the minimum duty cycle Dmin, and the voltage Vset of the first DC-DC converter and the second DC-DC converter; When Vset>(Dmax-Dmin)*Vin, the DSP chip controls the first DC-DC converter and the second DC-DC converter to add voltage and output voltage through the double-pole double-throw switch K3, so that the first DC-DC converter and the second DC-DC converter output a voltage of 0.5Vset respectively; When Vset<(Dmax-Dmin)*Vin, the DSP chip controls the first DC-DC converter and the second DC-DC converter to perform voltage subtraction output through the double-pole double-throw switch K3, so that the duty cycle of the first DC-DC converter or the second DC-DC converter is Dmin, and the duty cycle of the other is Vset / Vin+Dmin. When the duty cycles of the first DC-DC converter and the second DC-DC converter are close, zero voltage charging and discharging are performed; When Vset is less than 0, the DSP chip controls the first DC-DC converter and the second DC-DC converter to perform voltage subtraction output through the double-pole double-throw switch K3, so that the duty cycle values ​​of the first DC-DC converter and the second DC-DC converter are different, so that the output negative voltage has a value range of (Dmin-Dmax)*Vin to 0.

2. A bidirectional power supply control method with a wide voltage range as claimed in claim 1, characterized in that: The bidirectional power supply control system with a wide voltage range comprises: AC power distribution module; An AC-DC converter connected to the AC power distribution module; An energy bidirectional conversion module connected to the AC-DC converter; A host computer connected to the energy bidirectional conversion module; The energy bidirectional conversion module comprises: A first DC-DC converter, one end of which is connected to the AC-DC converter; A second DC-DC converter, one end of which is connected to the AC-DC converter; a current sensor, one end of which is connected to the other end of the first DC-DC converter; A power output unit, connected to the current sensor and the other end of the second DC-DC converter respectively; A voltage sensor is connected in parallel between the power output unit and the load; Temperature sensor; A signal processing unit, connected to the current sensor, the voltage sensor and the temperature sensor respectively; A DSP chip is connected to the first DC-DC converter, the second DC-DC converter, the power output unit, the signal processing unit and the host computer respectively; The first DC-DC converter includes a capacitor Ci1, a capacitor Co1, a resistor R1, a resistor R2, an inductor L1, a MOS transistor V1 and a MOS transistor V2; The positive electrode of the capacitor Ci 1 is connected to the positive electrode of the AC-DC converter and the pin 2 of the MOS tube V1, and the negative electrode is connected to the negative electrode of the AC-DC converter, the resistor R2, the pin 3 of the MOS tube V2, the negative electrode of the capacitor Co1 and the power output unit; the pin 1 of the MOS tube V1 is connected to the resistor R1 and the DSP chip, and the pin 3 is connected to the resistor R1, the inductor L1 and the pin 2 of the MOS tube V2; the pin 1 of the MOS tube V2 is connected to the resistor R2 and the DSP chip; the inductor L1 is connected to the positive electrode of the capacitor Co1 and the current sensor; The second DC-DC converter includes a capacitor Ci2, a capacitor Co2, a resistor R3, a resistor R4, an inductor L2, a MOS transistor V3 and a MOS transistor V4; The positive electrode of the capacitor Ci2 is connected to the positive electrode of the AC-DC converter and the pin 2 of the MOS tube V3, and the negative electrode is connected to the negative electrode of the AC-DC converter, the resistor R4, the pin 3 of the MOS tube V4, the negative electrode of the capacitor Co2 and the power output unit; the pin 1 of the MOS tube V3 is connected to the resistor R3 and the DSP chip, and the pin 3 is connected to the resistor R3, the inductor L2 and the pin 2 of the MOS tube V4; the pin 1 of the MOS tube V4 is connected to the resistor R4 and the DSP chip; the inductor L2 is connected to the positive electrode of the capacitor Co2 and the power output unit.

3. A bidirectional power supply control method with a wide voltage range as claimed in claim 2, characterized in that: The signal processing unit includes a high-precision AD chip U2, a capacitor C1, a resistor R5, a resistor R6, a resistor R7, a resistor R8 and an operational amplifier U3; One end of the high-precision AD chip U2 is connected to the DSP chip, and the other end is connected to the resistor R5 and the capacitor C1; pin 2 of the operational amplifier U3 is connected to the resistor R7 and the resistor R6, pin 3 is connected to the resistor R8, and pin 6 is connected to the resistor R5 and the resistor R6; the capacitor C1 and the resistor R8 are both grounded; the resistor R7 is connected to the current sensor, the voltage sensor and the temperature sensor.

4. A bidirectional power supply control method with a wide voltage range as claimed in claim 2, characterized in that: The power output unit includes a capacitor Co3, a MOS tube V5, a MOS tube V6, a double-pole double-throw switch K1 and a double-pole double-throw switch K3; The positive electrode of the capacitor Co3 is connected to the current sensor, the voltage sensor and the pin 2 of the MOS tube V5, and the negative electrode is connected to the pin 2 of the double-pole double-throw switch K3, the pin 2 of the double-pole double-throw switch K1 and the voltage sensor; the pin 1 of the double-pole double-throw switch K3 is connected to the first DC-DC converter, and the pins 3 and 4 are connected to the second DC-DC converter; the pin 2 of the MOS tube V6 is connected to the pin 3 of the MOS tube V5, and the pin 3 is connected to the pin 1 of the double-pole double-throw switch K1; the pins 3 and 4 of the double-pole double-throw switch K1 are connected to the voltage sensor; Pin 1 of the MOS tube V5, pin 1 of the MOS tube V6, pin 1 of the double-pole double-throw switch K1, and pin 5 of the double-pole double-throw switch K3 are all connected to the DSP chip.

5. A bidirectional power supply control method with a wide voltage range as claimed in claim 4, characterized in that: The double-pole double-throw switch K1 and the double-pole double-throw switch K3 are both electrically controlled switches.

6. A bidirectional power supply control method with a wide voltage range as claimed in claim 2, characterized in that: The voltage sensor is a four-wire voltage sensor.

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