阅读说明：本技术 模块化的能输出任意波形的大电流电流源 (Modular high-current source capable of outputting arbitrary waveforms ) 是由 陈耀军 陈柏超 田翠华 郭俊华 于 2020-12-09 设计创作，主要内容包括：公开了一种模块化的能输出任意波形的大电流电流源,包括：若干个并联的恒流源模块,其中每个所述恒流源模块包括正负电流取样电阻R-(C1)、R-(C2),正负电流取样电阻一端连接MOS管的源极,另一端和控制参考地相连并作为电源输出的正极,电源输出的负极则和输入直流电源的中心点相连,这样实现了电源的正负电流支路的独立控制,方便电源模块的并联,同时控制电路的工作电源和输入直流电源大小以及负载大小无关。模块化的所述恒流源模块并联来实现最终的大电流输出,并通过增加并联所述恒流源模块的数量来调整最大电流的输出。(Disclosed is a modular high-current source capable of outputting arbitrary waveforms, comprising: a plurality of parallel constant current source modules, wherein each constant current source module comprises a positive and negative current sampling resistor R C1 、R C2 The power supply control circuit comprises a power supply module, a positive current sampling resistor, a negative current sampling resistor, a control reference ground, a power supply module and a control circuit, wherein the power supply module is connected with the power supply module through the positive current sampling resistor and the negative current sampling resistor, the positive current sampling resistor and the negative current sampling resistor are connected with the power supply module through the control circuit, the other end of the positive current sampling resistor and the negative current sampling resistor are connected with the control reference ground and serve as the positive pole of the power supply output, the negative pole of the power supply. The modularized constant current source modules are connected in parallel to realize final large current output, and the output of the maximum current is adjusted by increasing the number of the parallel constant current source modules.)

1. A modular high current source capable of outputting arbitrary waveforms, comprising:

a plurality of parallel constant current source modules, the constant current source modules comprising:

the power circuit comprises a positive power branch and a negative power branch, the positive power branch is connected with a plurality of NMOS tubes in parallel in series, the drain electrodes of the NMOS tubes are connected with the positive electrode of an input power supply, and the source electrodes of the NMOS tubes are connected with a positive current sampling resistor R_C1One end of the positive current sampling resistor R is connected with the other end of the positive current sampling resistor R_C1The other end is connected with a power supply load R_LThe power load R, the positive reference terminal of_LThe negative reference end of the negative power branch circuit is connected with the serial middle point of the input power supply, the negative power branch circuit is connected with a plurality of PMOS tubes in parallel, the drain electrodes of the PMOS tubes are connected with the negative electrode of the input power supply, and the source electrodes of the PMOS tubes and the negative current sampling resistor R are connected with each other_C2One end of the negative current sampling resistor R is connected with the negative current sampling resistor R_C2And the other end of said power supply load R_LA positive reference terminal connected to the power supply load R, a control reference ground_LThe positive reference end is connected;

a control circuit including an operational amplifier A₁、A₂The operational amplifier A₁、A₂The same current given signal is connected to the same in-phase input terminal of the operational amplifier A₁、A₂The inverting input end of the operational amplifier is respectively connected with the source electrodes of the NMOS tube and the PMOS tube, and the operational amplifier A₁、A₂The output end of the power amplifier is respectively connected with the input ends of a first complementary power amplifier and a second complementary power amplifier, and the first complementary power amplifier and the second complementary power amplifier are respectively connected with the grids of the NMOS tube and the PMOS tube through grid driving resistors.

2. The modular high-current source capable of outputting any waveform according to claim 1, further comprising two three-phase step-down transformers, wherein output ends of the two three-phase step-down transformers are connected in series after passing through a rectifying and filtering circuit to serve as the input power source of the constant current source module.

Technical Field

The application relates to the field of linear power supplies, in particular to the field of power supplies which have high requirements on output current precision, complex waveform requirements and large amplitude.

Background

In some sensor and switch relay contact testing processes, a large current source is used, and the testing of a large-capacity battery or super capacitor application system needs a standard current source to simulate the current characteristics of a battery or a capacitor, so that high-precision large current capable of providing complex current waveforms is needed. In order to ensure the accuracy of the current waveform and reduce system interference, a linear power supply is generally used.

In order to obtain the required current, there are two general approaches, one is to use a high-precision voltage source and a resistance load connected in series to generate the required current, but the change of temperature will change the resistance value to cause the change of the output current, so that it is difficult to obtain the high-precision current. And the load resistance is not flexible to adjust, the continuous adjustment of the current amplitude is difficult to realize, and the power consumption is larger.

The other method is to change the feedback quantity of control into output current on the basis of a linear voltage source circuit so as to realize the control of the output current, and the circuit structure generally adopts a voltage follower structure based on an NMOS tube and a PMOS tube, but when the load impedance is larger, the control voltage of a power tube output by the control circuit is required to be higher, and a complex voltage amplification circuit needs to be designed. In order to enlarge the output current, MOS (metal oxide semiconductor) tubes are generally connected in parallel, but the modular design is difficult to realize, and the increase and decrease of the maximum output current are realized by increasing and decreasing modules.

Disclosure of Invention

The application provides a modular can export heavy current source of arbitrary waveform adopts modular design structure, can adjust the ability of current source output current through the quantity that increases and decreases parallel constant current source module, can improve the reliability of power greatly through increasing redundant module. The modular design also improves current source maintainability.

According to an aspect of the embodiments of the present application, there is provided a modular high-current source capable of outputting an arbitrary waveform, including:

a plurality of parallel constant current source modules, the constant current source modules comprising:

the power circuit comprises a positive power branch and a negative power branch, the positive power branch is connected with a plurality of NMOS tubes in parallel in series, the drain electrodes of the NMOS tubes are connected with the positive electrode of an input power supply, and the source electrodes of the NMOS tubes and a positive current sampling circuitResistance R_C1One end of the positive current sampling resistor R is connected with the other end of the positive current sampling resistor R_C1The other end is connected with a power supply load R_LThe power load R, the positive reference terminal of_LThe negative reference end of the negative power branch circuit is connected with the serial middle point (power ground) of the input power supply, the negative power branch circuit is connected with a plurality of PMOS tubes in parallel, the drain electrodes of the PMOS tubes are connected with the negative electrode of the input power supply, and the source electrodes of the PMOS tubes and the negative current sampling resistor R are connected with each other_C2One end of the negative current sampling resistor R is connected with the negative current sampling resistor R_C2And the other end of said power supply load R_LA positive reference terminal connected to the power supply load R, a control reference ground_LThe positive reference end is connected;

a control circuit including an operational amplifier A₁、A₂The operational amplifier A₁、A₂The same current given signal is connected to the same in-phase input terminal of the operational amplifier A₁、A₂The inverting input end of the operational amplifier is respectively connected with the source electrodes of the NMOS tube and the PMOS tube, and the operational amplifier A₁、A₂The output end of the power amplifier is respectively connected with the input ends of a first complementary power amplifier and a second complementary power amplifier, and the first complementary power amplifier and the second complementary power amplifier are respectively connected with the grids of the NMOS tube and the PMOS tube through grid driving resistors.

In some examples, the constant current source module further comprises two three-phase step-down transformers, and output ends of the two three-phase step-down transformers are connected in series after passing through a rectifying and filtering circuit to serve as the input power source of the constant current source module.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly described below.

Fig. 1 shows a block diagram of a modular high-current source capable of outputting arbitrary waveforms according to an embodiment of the present application.

Fig. 2 shows a topology of a constant current source module according to an embodiment of the present application.

Fig. 3 shows a block diagram of a system management control module according to an embodiment of the present application.

Detailed Description

Fig. 1 shows a block diagram of a modular high-current source capable of outputting any waveform, which comprises a system management control module and a plurality of parallel constant current source modules. The system management control module is used for completing the functions of man-machine interaction, control management and system monitoring. The constant current source modules have the same input and are two groups of same voltage sources, and the constant current source modules are obtained by rectifying and filtering two independent three-phase step-down transformers. The number of the constant current source modules is not limited, and when 10 constant current source modules capable of outputting +/-100A-level current are connected in parallel, the whole current source can output +/-1000A-level current.

The constant current source module is a core component of the whole current source and needs to solve three key problems: firstly, the input power supply and the control circuit are inconsistent in power supply voltage, and the structure of the traditional linear amplifier needs to be improved; secondly, the MOS tube parallel connection problem is solved, which requires that the MOS tube with better consistency is selected as much as possible and a drive circuit has enough drive capability; thirdly, the problems of control precision and control speed require the control circuit to adopt an amplifier with high gain, high speed and low temperature drift.

Every constant current source module includes positive and negative current sampling resistance, and the source electrode of MOS pipe is connected to positive and negative current sampling resistance one end, and the other end links to each other with the control reference ground and as power output's positive pole, and power output's negative pole then links to each other with input DC power supply's central point, has realized the independent control of the positive and negative current branch road of power like this, makes things convenient for parallelly connected of power module, and control circuit's working power supply and input DC power supply size and load size are irrelevant simultaneously.

Figure 2 shows a topology of a constant current source module. As shown in fig. 2, the positive power branch of the upper half generates a positive current and the negative power branch of the lower half generates a negative current. Q₁₁～Q₁₄And Q₂₁～Q₂₄The NMOS transistors and the PMOS transistors are respectively connected in parallel and are main circuit current adjusting transistors. Q₁、Q₂And Q₃、Q₄Respectively forming complementary circuits for driving respective MOS transistors, R_C1And R_C2Sampling resistor for positive and negative currentIt is a precision high stability resistor. Vref is given current value, when Vref is positive, the lower half part of operational amplifier A₂Output high level, Q₃Fully opening, outputting high level, quickly cutting off parallel PMOS tube, and operating amplifier A of upper half part₁Then pass through Q₁And Q₂Control Q₁₁～Q₁₄Thereby controlling the positive current to track Vref. On the contrary, when Vref is negative, the NMOS tube of the upper half part is cut off, and the lower half part outputs negative current. It is apparent that changing the waveform and amplitude of Vref changes the waveform and amplitude of the output current. The number of the NMOS tubes connected in parallel in the positive power branch and the number of the PMOS tubes connected in parallel in the negative power branch are not limited in the application.

When a positive current is output, the NMOS tube of the positive power branch works, and the PMOS tube of the negative power branch is cut off; when a negative current is output, the PMOS tube of the negative power branch circuit works, the NMOS tube of the positive power branch circuit is cut off, and the positive power branch circuit and the negative power branch circuit work in turn as required, so that the output of any current waveform is realized.

The current source adopts the modularized design, the capacity of adjusting the output current of the system by increasing or decreasing the number of the constant current source modules which are connected in parallel is realized, and the reliability of the system is improved by increasing the redundancy modules. The modular design improves system maintainability. The positive and negative output currents of the constant current source module have independent positive and negative power branches and independent positive and negative current sampling resistors (R)_C1，R_C2) And an independent positive and negative current closed-loop control circuit. One end of the positive and negative current sampling resistor is connected with the control reference ground, and the other end of the positive and negative current sampling resistor is respectively connected with the source electrodes of the NMOS tube and the PMOS tube. The inverting input ends of the closed-loop control operational amplifiers of positive and negative currents are respectively connected with the source electrodes of the NMOS tube and the PMOS tube, and the two operational amplifiers (A)₁、A₂) Is connected to the same current reference signal. When the current reference signal is positive, the output of the negative current control operational amplifier is positive, the PMOS tube is cut off, and the positive current sampling resistor R_C1The voltage of the power supply follows the given voltage and outputs a positive current with a given magnitude; on the contrary, when the current reference signal is negative, the positive current control operational amplifier output is negative, and the NMOS tube is cut offNegative current sampling resistor R_C2The voltage changes along with the given current signal, and negative current with given magnitude is output. The output of the operational amplifier is controlled to be connected in series with a complementary power amplifier consisting of MOS tubes, the driving capability of the operational amplifier is increased, and the grid of each MOS tube connected in parallel is connected in series with the same driving resistor, so that the driving consistency of the MOS tubes is ensured.

The block diagram of the system management control module is shown in fig. 3, the control voltage of the output current is generated by a CPU through an FPGA, the CPU transmits corresponding waveform data to the FPGA, the FPGA outputs the waveform data by using a DDS technology, the waveform data is changed into an analog signal by a high-speed DA, and after being filtered by a filter, the same given voltage is transmitted to each constant current source module by using a voltage follower.

Meanwhile, the temperature, the input and output voltage and current, the input and output voltage and the current of the current source radiator and the temperature in the case, and the input and output voltage and current are monitored through a temperature and input and output voltage and current acquisition circuit and an AD converter.

Through setting, the current source can work in a constant voltage, constant current and constant power mode, and various output current waveforms can be edited according to requirements, so that various operation conditions required by the electric energy electrical property test system can be simulated.