CN105656318A - Alternating current/direct current energy reclaiming type electronic simulation loading device and control method thereof - Google Patents

Abstract

An AC/DC feed type electronic analog load device and a control method thereof, comprising a controller, an input-side conversion unit, an input-side H-bridge inverter unit, an isolated high-frequency transformer, an output-side H-bridge rectifier unit, an output-side conversion unit, Composed of display unit, input voltage transformer, input current transformer, output voltage transformer, output current transformer, DC voltage transformer, input AC terminal, output AC terminal and output DC terminal, it is an electronic analog load for energy feedback , the output is fed back to an AC or DC power supply. The input side can simulate three modes of constant power, constant current and constant impedance. In addition, it can simulate various load characteristic curves, and the power factor can be adjusted. It can be set through the display unit panel, or it can be set by the host computer through communication. The invention has obvious power-saving advantages in load test research, and has the characteristics of flexible simulation of various load characteristics and AC/DC feedback.

Description

AC and DC energy feeding electronic analog load device and control method thereof

technical field

The invention relates to the technical field of power electronics, in particular to an AC/DC energy feeding electronic analog load device and a control method thereof.

Background technique

With the increasingly widespread application of power electronic devices, there are more and more new products and new technologies. At present, various power electronic device factory tests and reliability tests before use (mainly aging tests) generally use the method of resistive energy discharge to conduct physical experiments, and it is difficult to test and test other load characteristics. To overcome this problem, it is necessary to test by electronically simulating a power load. It is an experimental device designed and realized by using power electronics technology, computer control technology and power system automation technology, and is used for checking and testing various DC power supplies.

The difference between this design and the general electronic load is that: on the one hand, the maximum amount of electric energy it absorbs from the tested power supply can be recycled by the tested power supply, and its loss is only the switching loss and line loss of the PWM converter, so as to maximize On the other hand, because the PWM converter used works in the switch state, it is easy to meet the requirements of high-power applications compared with the electronic loads that generally work in the amplified state, so it has a wider application field. .

The invention is used to replace the traditional resistive power load for related power experiments, and can also be applied to the test experiments of instruments and equipment, and meets the IEEE-519 standard. Compared with the resistive load, the present invention has the following advantages: ①Because its working mode is to use power electronic conversion technology to feed back the output energy of the equipment to be tested to the power grid under the premise of completing the test power experiment, which saves energy, On the other hand, it does not generate a lot of heat, which avoids the problem of rising ambient temperature in the test site; ②Small size and light weight. Since the electronic load does not turn the test power into heat, it is not necessary to use a bulky resistance box and cooling equipment, thus saving installation space; ③ The simulated power is continuously adjustable. As we all know, the resistive load has to be adjusted stepwise when the power is high, and it is very limited in use. The user can set the required power (or power output current)-time change curve through the computer interface during specific use. After the equipment is started, its load will run strictly according to the setting; ④Because the energy feedback method is adopted, the test site does not need to be equipped with a large power supply capacity. The existing electronic feedback load has a single function, and it is difficult to meet the needs of the rapid development of power electronics technology.

Contents of the invention

In view of the above problems, the object of the present invention is to provide an AC/DC feed type electronic analog load device and its control method. The device has obvious advantages in power saving in load testing and research, and has the characteristics of flexibly simulating various load characteristics and AC/DC feedback.

Technical solution of the present invention is as follows:

An AC/DC feed type electronic analog load device is characterized in that the device includes: a controller, an input side conversion unit, an input side H bridge inverter unit, an isolated high frequency transformer, an output side H bridge rectifier unit, an output side conversion unit unit, input voltage transformer, input current transformer, output voltage transformer, output current transformer, DC voltage transformer, input AC terminal, output AC terminal, output DC terminal and display unit,

The input end of the input-side conversion unit is connected to the input AC terminal, the output end of the input-side conversion unit is connected to the input end of the input-side H-bridge inverter unit, and the input-side H-bridge inverter The output end of the unit is connected to the input end of the isolated high-frequency transformer, the output end of the isolated high-frequency transformer is connected to the input end of the H-bridge rectifier unit on the output side, and the H-bridge rectifier unit on the output side is The output end is connected to the input end of the output-side conversion unit, the output end of the output-side conversion unit is connected to the output AC terminal; the output DC terminal is connected to the output-side H-bridge rectifier unit the output end of the DC voltage sensor; the input side of the DC voltage sensor is connected to the output end of the H-bridge rectifier unit on the output side;

The input side of the input voltage transformer is connected to the main circuit of the input end of the conversion unit at the input side, and the voltage signal output end of the input voltage transformer is connected to the corresponding input voltage signal input port of the controller connected; the input current transformer is connected in series in the circuit between the input side conversion unit and the input AC terminal, the AC current signal output terminal of the input current transformer is connected to the controller The input port of the AC input current signal is connected;

The input side of the output voltage transformer is connected to the main circuit of the output end of the output side conversion unit, and the voltage signal output end of the output voltage transformer is connected to the input of the output AC voltage signal of the controller The ports are connected; the output current transformer is connected in series in the circuit of the output end of the output-side conversion unit, and the current signal output end of the output current transformer is connected to the output current signal input port of the controller; The voltage signal output end of the DC voltage sensor is connected to the DC voltage signal input port of the controller;

The output pulse width modulation signal PWM _S123 and PWM _O123 ports of the controller are respectively connected to the PWM control signal end of the input side conversion unit and the PWM control signal end of the output side conversion unit; the control The local communication port of the controller is connected with the communication port of the display unit, and the remote communication port of the controller is connected with the host computer.

Both the input-side conversion unit and the output-side conversion unit include a three-phase inverter structure connected to the three-phase AC and a common DC bus capacitor, wherein each phase inverter structure includes: a first insulated gate bipolar transistor (abbreviated as IGBT) and the second IGBT, the emitter of the first IGBT is connected to the collector of the second IGBT, the collector of the first IGBT is connected to the second IGBT through the common DC bus capacitance The emitter is connected to the control terminal of the first IGBT and the second IGBT as the control terminal of the inverter unit, which is connected to the PWM signal output terminal of the inverter unit of the control unit corresponding to the PWM signal of the corresponding phase inverter unit, so The signals of the control terminals of the first IGBT and the second IGBT are opposite, the collector of the second IGBT is the AC output terminal of the inverter unit, the two ends of the common DC bus capacitor are the DC input terminals of the inverter unit, and its voltage is inverse DC voltage U _DC of the transformer unit;

Since the control signals of the control terminal of the first IGBT and the control terminal of the second IGBT are opposite, the PWM signal of the inverter unit output by the output terminal of the inverter unit PWM signal of the control unit can generate the opposite inverter through an external inverter or internally by the control unit. The PWM signal of the inverter unit, and then input the PWM signal of the inverter unit and the opposite PWM signal of the inverter unit to the control terminal of the first IGBT and the control terminal of the second IGBT correspondingly.

Both the input-side H-bridge inverter unit and the output-side H-bridge inverter unit include: a first IGBT, a second IGBT, a third IGBT, and a fourth IGBT, and the emitter of the first IGBT is connected to the first IGBT. For the collectors of the three IGBTs, the collector of the first IGBT is connected to the emitter of the third IGBT through a common DC bus capacitance; the emitter of the second IGBT is connected to the collector of the fourth IGBT, so The collector of the second IGBT is connected to the emitter of the fourth IGBT through the common DC bus capacitance;

The control signals of the control terminal of the first IGBT and the control terminal of the third IGBT are opposite, the control signals of the control terminal of the second IGBT and the control terminal of the fourth IGBT are opposite; the control signals of the control terminal of the first IGBT and the control terminal of the fourth IGBT The control signals are the same, the control signals of the control terminal of the second IGBT and the control terminal of the third IGBT are the same, and the control signal is generated locally, and is a signal with a frequency of 10k-50kHz and a duty cycle of 50%.

The control method of the AC/DC energy-feeding electronic analog load device is characterized in that the method includes an output-side conversion unit control method, an input-side conversion unit control method and an energy feedback optimization method.

The control method for the conversion unit on the output side includes the following steps:

① Given the control parameters of the first proportional integrator, the second proportional integrator, and the third proportional integrator: 1<k _p1 <100, 0.1<k _i1 <10, 1<k _p2 <100, 0.1<k _i2 < 10. 1<k _p3 <100, 0.1<k _i3 <10, measure the output side AC voltage u _o and AC current i _o , and obtain the output side AC voltage amplitude U _s and the output side AC current amplitude I _d , I _q and the power angle θ of the AC voltage and AC current at the output side;

②Set the given value of DC voltage U _DCref , measure the DC voltage U _DC , and control the output value u _d0 of the difference between the given value of DC voltage U _DCref and the measured DC voltage U _DC through the first proportional integrator as follows:

u _d0 ＝k _p1 *(U _DCref -U _DC )+k _i1 *∫(U _DCref -U _DC )dt

Among them, U _DCref is the given value of DC voltage, and the per unit value is 1~1.2;

③Combine the output value of the first proportional integrator with the measured AC voltage U _S and current I _d at the output side to obtain the active power control value u _d of the inverter unit through the second proportional integrator. The specific formula is as follows:

u _d ＝k _p2 *(u _d0 -I _d )+k _i2 *∫(u _d0 -I _d )dt+U _S

④The AC current I _q on the output side measured is passed through the third proportional integrator to obtain the reactive power control value u _q of the inverter unit. The specific formula is as follows:

u _q =k _p3 *I _q +k _i3 *∫I _q dt;

⑤According to the reactive power control quantity u _q and active power control quantity u _d , after dq-abc Parker inverse transformation, the pulse width modulation PWM signal of the three-phase inverter unit is obtained:

The output voltage of the conversion unit at the output side is adjusted.

The control method of the conversion unit on the input side includes the following steps:

Step 1, constant power control:

Under constant power control, the constant power control is as follows:

① Given the control parameters of the 4th proportional integrator, the 5th proportional integrator, and the 6th proportional integrator: 1<k _p4 <100, 0.1<k _i4 <10, 1<k _p5 <100, 0.1<k _i5 < 10. 1<k _p6 <100, 0.1<k _i6 <10, 1<k _p7 <100, 0.1<k _i7 <10, measure the input side AC voltage u _s and AC current i _s , and obtain the input side AC Voltage amplitude U _S1 , input side AC current amplitude I _d1 , I _q1 and power angle θ ₂ between input side AC voltage and AC current, calculate active power P=U _S1 ×I _d1 , reactive power Q=U _S1 × I _q1 ;

② Set the given value of active power P _ref , control the difference between P _ref and the calculated P by the fourth proportional integrator, and calculate the intermediate control variable u _d20 according to the following formula:

u _d20 ＝k _p4 *(P _ref -P)+k _i4 *∫(P _ref -P)dt

③According to the intermediate control variable u _d20 output by the fourth proportional integrator, combined with the measured input-side AC voltage U _S1 and current I _d1 , the control variable u _d2 of the inverter unit is obtained through the following formula:

u _d2 ＝k _p5 *(u _d20 -I _d1 )+k _i5 *∫(u _d20 -I _d1 )dt+U _S1

④ Set the given value of reactive power Q _ref , control the difference between Q _ref and the calculated reactive power Q through the sixth proportional integrator, and calculate the intermediate control quantity u _q20 according to the following formula:

u _q20 ＝k _p6 *(Q _ref -Q)+k _i6 *∫(Q _ref -Q)dt

⑤According to the output value of the sixth proportional integrator, combined with the measured AC current I _q1 on the input side, after the seventh proportional-integral control, the control quantity u _q2 of the inverter unit is calculated according to the following formula:

u _q2 ＝k _p7 *(u _q20 -I _q1 )+k _i7 *∫(u _q20 -I _q1 )dt

⑥According to the control variables u _d2 and u _q2 , after dq-abc Parker inverse transformation, the pulse width modulation PWM signal of the three-phase inverter unit is obtained:

The output voltage of the conversion unit at the input side is adjusted.

Step 2, constant current control:

Under constant current control, the constant current control is as follows: given the active current value I _dref , in the above steps, u _d20 =I _dref ;

Step 3, constant resistance control:

Under constant resistance control, the constant resistance control is as follows: Given a resistance reference value R _ref , in the above step 1, u _d20 =U _s1 /I _dref .

The energy feedback optimization model function of the described energy feedback optimization method:

$<span\; class="notranslate">\; \&lsqb;</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; \&rsqb;</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; b</span>}\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; e</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; D.</span>}\mathrm{<span\; class="notranslate">\; C</span>}}<span\; class="notranslate">\; -</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; u</span>}}}_{\mathrm{<span\; class="notranslate">\; D.</span>}\mathrm{<span\; class="notranslate">\; C</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>$

in, is the average value of U _DC .

Features of the present invention are as follows:

1. The present invention is an electronic analog load for energy feedback, which performs energy feedback through an AC or DC power supply.

2. The present invention can simulate three modes of constant power, constant current and constant impedance, and the power factor is adjustable.

3. The present invention can simulate various load characteristic curves, which can be set through the panel of the display unit, or can be set by the upper computer through communication.

4. The present invention has obvious advantages in saving electricity in the load test.

Description of drawings

Fig. 1 is a schematic structural diagram of an AC/DC feed type electronic analog load device of the present invention.

Fig. 2 is a schematic diagram of the topology of the conversion unit at the input/output side of the present invention.

Fig. 3 is a schematic diagram of an H-bridge inverter unit at the input/output side of the present invention.

Fig. 4 is a control block diagram of the conversion unit at the output side of the present invention.

Fig. 5 is a control block diagram of the conversion unit at the input side of the present invention.

detailed description

The present invention will be further described below in conjunction with the embodiments and accompanying drawings, but the protection scope of the present invention should not be limited thereby.

Please refer to FIG. 1 first. FIG. 1 is a schematic structural diagram of an AC/DC feed type electronic analog load device according to the present invention. It can be seen from the figure that the AC/DC energy feeding electronic analog load device of the present invention includes: a controller 2, an input side conversion unit 3, an input side H-bridge inverter unit 4, an isolation high-frequency transformer 5, and an output side H-bridge rectifier unit 6 , output side conversion unit 7, display unit 16, input voltage transformer 8, input current transformer 9, output voltage transformer 10, output current transformer 11, DC voltage transformer 12, input AC terminal 13, output AC terminal 14 , Output DC terminal 15.

The input end of the input-side conversion unit 3 is connected to the input AC terminal 13, and the output end of the input-side conversion unit 3 is connected to the input end of the input-side H-bridge inverter unit 4; The output end of the H-bridge inverter unit 4 on the input side is connected to the input end of the isolated high-frequency transformer 5; the output end of the isolated high-frequency transformer 5 is connected to the H-bridge rectifier unit 6 on the output side. The input end is connected; the output end of the output side H-bridge rectifier unit 6 is connected with the input end of the output side conversion unit 7; the output end of the output side conversion unit 7 is connected with the output AC terminal 14 connected; the output DC terminal 15 is connected to the output end of the H-bridge rectifier unit 6 on the output side;

The input side of the input voltage transformer 8 is connected to the main circuit of the input end of the input side transformation unit 3, and the voltage signal output end of the input voltage transformer 8 is connected to the corresponding input of the controller 2 The voltage signal input port is connected; the input current transformer 9 is connected in series in the input main circuit of the input side transformation unit 3, and the current signal output terminal of the input current transformer 9 is connected to the controller 2 The corresponding input current signal input port is connected;

The input side of the output voltage transformer 10 is connected to the main circuit of the output end of the output side conversion unit 7, and the voltage signal output end of the output voltage transformer 10 is connected to the corresponding output of the controller 2 The voltage signal input port is connected; the output current transformer 11 is connected in series in the output main circuit of the output side conversion unit 7, and its current signal output port is corresponding to the output current signal input port of the controller 2 connected;

The input side of the DC voltage sensor 12 is connected to the output DC terminal circuit of the H-bridge rectifier unit 6 on the output side, and the voltage signal output terminal of the DC voltage sensor 12 is connected to the DC voltage corresponding to the controller 2. The voltage signal input port is connected, as mentioned above;

The PWM _S123 and PWM _O123 ports of the output of the controller 2 are respectively connected to the PWM control signal end of the input side conversion unit 3 and the PWM control signal end of the output side conversion unit 7; The local communication port of the controller 2 is connected with the communication port of the display unit 16, and the remote communication port of the controller 2 is connected with the host computer.

In the AC/DC feed type electronic analog load device system of the present invention, the input-side conversion unit and the output-side conversion unit include a three-phase inverter structure connected to the three-phase AC and a common DC bus capacitor, wherein each phase inverter structure is It includes: a first insulated gate bipolar transistor (hereinafter referred to as IGBT), a second IGBT, wherein the emitter of the first IGBT is connected to the collector of the second IGBT, and the collector of the first IGBT is connected to the collector of the first IGBT through the The common DC bus capacitor is connected to the emitter of the second IGBT, and the control terminals of the first IGBT and the second IGBT as the control terminals of the inverter unit are connected to the control unit corresponding to the PWM signal of the corresponding phase inverter unit. The PWM signal output terminals of the inverter unit are connected, wherein the signals of the control terminals of the first IGBT and the second IGBT are opposite, the collector of the second IGBT is the AC output terminal of the inverter unit, and the two ends of the common DC bus capacitor are inverted The DC input terminal of the inverter unit, whose voltage is the DC voltage U _DC of the inverter unit.

In the above solution, since the control terminal of the first IGBT and the control terminal of the second IGBT have opposite signals, the PWM signal of the inverter unit output by the PWM signal output terminal of the inverter unit of the control unit can be generated by an external inverter or internally by the control unit The opposite PWM signal of the inverter unit, and then correspondingly input the PWM signal of the inverter unit and the opposite PWM signal of the inverter unit to the control terminal of the first IGBT and the control terminal of the second IGBT.

In the AC/DC feed type electronic analog load device system of the present invention, the structures of the input-side H-bridge inverter unit and the output-side H-bridge inverter unit (see FIG. 3 ) include: a first IGBT, a second IGBT, a third IGBT, the fourth IGBT, wherein the emitter of the first IGBT is connected to the collector of the third IGBT, and the collector of the first IGBT is connected to the emitter of the third IGBT through the common DC bus capacitance The emitter of the second IGBT is connected to the collector of the fourth IGBT, and the collector of the second IGBT is connected to the emitter of the fourth IGBT through the common DC bus capacitance.

The control signals of the control terminal of the first IGBT and the control terminal of the third IGBT are opposite, the control signals of the control terminal of the second IGBT and the control terminal of the fourth IGBT are opposite; the control signals of the control terminal of the first IGBT and the control terminal of the fourth IGBT are the same , the control signal of the control terminal of the second IGBT is the same as that of the control terminal of the third IGBT. The control signal is generated locally and is a signal with a frequency of 10k-50kHz and a duty ratio of 50%.

The present invention also provides an AC/DC feed type electronic analog load control method,

Refer to Figure 4 for the control method of the conversion unit on the output side, including steps:

Given the control parameters of the first proportional integral control PI1, the second proportional integrator PI2, and the third proportional integrator PI3 1<k _p1 <100, 0.1<k _i1 <10, 1<k _p2 <100, 0.1<k _i2 <10, 1<k _p3 <100, 0.1<k _i3 <10, measure the output side AC voltage u _o and AC current i _o , and obtain the output side AC voltage amplitude U _s and the output side AC current amplitude I _d , I _q and the power angle θ of the AC voltage and AC current on the output side.

Set the DC voltage given value U _DCref , measure the DC voltage U _DC , and perform the first proportional-integral control (PI1) on the difference between the set DC voltage given value U _DCref and the measured DC voltage U _DC to obtain the intermediate control value u _d0 , whose calculation formula is:

u _d0 ＝k _p1 *(U _DCref -U _DC )+k _i1 *∫(U _DCref -U _DC )dt

Among them, U _DCref is the given value of DC voltage, and the per unit value is 1 to 1.2.

The output value of the above-mentioned first proportional integrator PI1 is combined with the measured output side AC voltage U _S and current I _d , and through the following formula including the second proportional integrator PI2, the control value u _d of the inverter unit is obtained. The specific formula is as follows :

u _d ＝k _p2 *(u _d0 -I _d )+k _i2 *∫(u _d0 -I _d )dt+U _S

The measured AC current I _q on the output side passes through the third proportional integrator PI3 to obtain the control value u _q of the inverter unit. The specific formula is as follows:

u _q =k _p3 *I _q +k _i3 *∫I _q dt

According to the reactive power control quantity u _q and active power control quantity u _d obtained in the above steps, after dq-abc Parker inverse transformation, the pulse width modulation PWM signal of the three-phase inverter unit is obtained to adjust the output voltage of the conversion unit on the output side.

The control method of the conversion unit on the input side, as shown in Fig. 5, includes

Step 1, constant power control:

Given the control parameters of the 4th proportional integrator PI4, the 5th proportional integrator PI5, the 6th proportional integrator PI6, and the seventh proportional integrator PI7 1<k _p4 <100, 0.1<k _i4 <10, 1<k _p5 <100, 0.1<k _i5 <10, 1<k _p6 <100, 0.1<k _i6 <10, 1<k _p7 <100, 0.1<k _i7 <10, measure input side AC voltage u _s and AC current i _s , and thus obtain the input-side AC voltage amplitude U _S1 , the input-side AC current amplitudes I _d1 , I _q1 and the power angle θ ₂ between the input-side AC voltage and AC current, and calculate the active power P=U _S1 ×I _d1 and Reactive power Q=U _S1 ×I _q1 .

Set constant power control, given value of active power P _ref , perform the fourth proportional integral control PI4 on the difference between P _ref and the calculated P, and obtain the intermediate control variable u _d20 , the calculation formula is

u _d20 ＝k _p4 *(P _ref -P)+k _i4 *∫(P _ref -P)dt

The above-mentioned fourth proportional integrator PI4 output value, combined with the measured input-side AC voltage U _S1 and current I _d1 , through the following formula, obtains the control variable u _d2 of the inverter unit, and the specific formula is as follows:

u _d2 ＝k _p5 *(u _d20 -I _d1 )+k _i5 *∫(u _d20 -I _d1 )dt+U _S1

Set the given value of reactive power Q _ref , and perform the sixth proportional integral control PI6 on the difference between Q _ref and the calculated reactive power Q to obtain the intermediate control quantity u _q20 , the calculation formula of which is

u _q20 ＝k _p6 *(Q _ref -Q)+k _i6 *∫(Q _ref -Q)dt

The above-mentioned sixth proportional integrator PI6 output value, combined with the measured input-side AC current I _q1 , passes through the seventh proportional-integral control PI7 to obtain the control variable u _q2 of the inverter unit. The specific formula is as follows:

u _q2 ＝k _p7 *(u _q20 -I _q1 )+k _i7 *∫(u _q20 -I _q1 )dt

According to the control variables u _d2 and u _q2 obtained in the above steps, after dq-abc Parker inverse transformation, the three-phase inverter unit pulse width modulation PWM signal is obtained to adjust the output voltage of the input side conversion unit.

Step 2, constant current control:

Given the active current value I _dref , in the above steps, u _d20 =I _dref .

Step 3, constant resistance control:

Given the resistance reference value R _ref , in the above step 1, u _d20 =U _s1 /I _dref .

The energy feedback optimization method of the present invention includes

Energy feedback optimization model function:

$<span\; class="notranslate">\; \&lsqb;</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; \&rsqb;</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; b</span>}\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; e</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; D.</span>}\mathrm{<span\; class="notranslate">\; C</span>}}<span\; class="notranslate">\; -</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; u</span>}}}_{\mathrm{<span\; class="notranslate">\; D.</span>}\mathrm{<span\; class="notranslate">\; C</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>$

in, is the average value of U _DC .

The AC/DC energy feeding type electronic analog load device of the present invention is an electronic analog load with energy feedback, and the output is fed back to the AC or DC power supply. The input side can simulate three modes of constant power, constant current and constant impedance. In addition, it can simulate various load characteristic curves, and the power factor can be adjusted. It can be set through the display unit panel, or it can be set by the host computer through communication. The invention has obvious power-saving advantages in load test research, and has the characteristics of flexible simulation of various load characteristics and AC/DC feedback.

Claims (7)

1. An AC/DC feed type electronic analog load device, characterized in that the device comprises: a controller (2), an input side conversion unit (3), an input side H bridge inverter unit (4), an isolation high frequency transformer (5), output side H-bridge rectifier unit (6), output side conversion unit (7), input voltage transformer (8), input current transformer (9), output voltage transformer (10), output current transformer (11), DC voltage transformer (12), input AC terminal (13), output AC terminal (14), output DC terminal (15) and display unit (16), The input end of the input-side conversion unit (3) is connected to the input AC terminal (13), and the output end of the input-side conversion unit (3) is connected to the input-side H-bridge inverter unit (4) The input end of this input side H-bridge inverter unit (4) is connected with the input end of the described isolation high-frequency transformer (5), and the output end of the isolation high-frequency transformer (5) is connected with the described The input end of the H-bridge rectifier unit (6) on the output side is connected, the output end of the H-bridge rectifier unit (6) on the output side is connected to the input end of the conversion unit (7) on the output side, and the output side The output end of the conversion unit (7) is connected to the output AC terminal (14); the output DC terminal (15) is connected to the output end of the H-bridge rectifier unit (6) on the output side; the DC The input side of the voltage sensor (12) is connected to the output end of the H-bridge rectifier unit (6) on the output side, and the voltage signal output end of the DC voltage sensor (12) corresponds to the controller (2) The DC voltage signal input port (U _DC ) is connected; The input side of the input voltage transformer (8) is connected to the main circuit of the input end of the input side conversion unit (3), and the voltage signal output end of the input voltage transformer (8) is connected to the The corresponding input voltage signal input port (Us) of the controller (2) is connected; the input current transformer (9) is connected in series with the input side conversion unit (3) and the input AC terminal (13) In the circuit between, the AC current signal output end of the input current transformer (9) is connected to the input port (Is) of the AC input current signal of the controller (2); The input side of the output voltage transformer (10) is connected to the main circuit of the output end of the output side transformation unit (7), and the voltage signal output end of the output voltage transformer (10) is connected to the The input port (Uo) of the output AC voltage signal of the controller (2) is connected; the described output current transformer (11) is connected in series in the circuit of the output end of the described output side transformation unit (7), and the output current The current signal output terminal of transformer (11) is connected with the output current signal input port (Io) of described controller (2); the voltage signal output terminal of described DC voltage sensor (12) is connected with described controller (2) The DC voltage signal input port is connected; The output pulse width modulation signal PWM _S123 and PWM _O123 ports of the controller (2) are respectively connected with the PWM control signal end of the input side conversion unit (3) and the PWM control signal terminal of the output side conversion unit (7). The control signal terminal is connected; the local communication port of the controller (2) is connected with the communication port of the display unit (16), and the remote communication port of the controller (2) is connected with the host computer. 2. The AC/DC feed type electronic analog load device according to claim 1, characterized in that, the input side conversion unit (3) and the output side conversion unit (7) both include a three-phase AC three-phase connection The inverter structure and the common DC bus capacitor (C), wherein each phase inverter structure includes: a first insulated gate bipolar transistor (abbreviated as IGBT) and a second IGBT, the emitter of the first IGBT is connected to the The collector of the second IGBT, the collector of the first IGBT is connected to the emitter of the second IGBT through the common DC bus capacitance, and the first IGBT as the control terminal of the inverter unit And the control terminal of the second IGBT, which is connected to the output terminal of the inverter unit PWM signal of the control unit corresponding to the PWM signal of the corresponding phase inverter unit, the signals of the control terminals of the first IGBT and the second IGBT are opposite, and the signals of the second IGBT The collector is the AC output terminal of the inverter unit, and the two ends of the common DC bus capacitor are the DC input terminals of the inverter unit, and its voltage is the DC voltage U _DC of the inverter unit; Since the control signals of the control terminal of the first IGBT and the control terminal of the second IGBT are opposite, the PWM signal of the inverter unit output by the output terminal of the inverter unit PWM signal of the control unit can generate the opposite inverter through an external inverter or internally by the control unit. The PWM signal of the inverter unit, and then input the PWM signal of the inverter unit and the opposite PWM signal of the inverter unit to the control terminal of the first IGBT and the control terminal of the second IGBT correspondingly. 3. The AC/DC feed type electronic analog load device according to claim 1, characterized in that, the input side H-bridge inverter unit (4) and the output side H-bridge inverter unit (6) both comprise: The first IGBT, the second IGBT, the third IGBT, and the fourth IGBT, the emitter of the first IGBT is connected to the collector of the third IGBT, and the collector of the first IGBT connects with the common DC bus capacitor (C) The emitter of the third IGBT is connected; the emitter of the second IGBT is connected to the collector of the fourth IGBT, and the collector of the second IGBT passes through the common DC bus capacitance (C) connected to the emitter of the fourth IGBT; The control signals of the control terminal of the first IGBT and the control terminal of the third IGBT are opposite, the control signals of the control terminal of the second IGBT and the control terminal of the fourth IGBT are opposite; the control signals of the control terminal of the first IGBT and the control terminal of the fourth IGBT The control signals are the same, the control signals of the control terminal of the second IGBT and the control terminal of the third IGBT are the same, and the control signal is generated locally, and is a signal with a frequency of 10k-50kHz and a duty cycle of 50%. 4. The control method of the AC/DC energy-feeding electronic analog load device according to claim 1, characterized in that the method comprises an output-side conversion unit control method, an input-side conversion unit control method, and an energy feedback optimization method. 5. The control method according to claim 4, characterized in that said output-side conversion unit control method comprises the following steps: ① Given the control parameters of the first proportional integrator (PI1), the second proportional integrator (PI2), and the third proportional integrator (PI3): 1<k _p1 <100, 0.1<k _i1 <10, 1<k _p2 <100, 0.1<k _i2 <10, 1<k _p3 <100, 0.1<k _i3 <10, measure the AC voltage u _o and the AC current i _o at the output side, and obtain the AC voltage amplitude U _s at the output side , the output side AC current amplitude I _d , I _q and the power angle θ between the output side AC voltage and AC current; ②Set the DC voltage given value U _DCref , measure the DC voltage U _DC , and control the output value u of the difference between the set DC voltage given value U _DCref and the measured DC voltage U _DC through the first proportional integrator (PI1) _d0 is: u _d0 ＝k _p1 *(U _DCref -U _DC )+k _i1 *∫(U _DCref -U _DC )dt Among them, U _DCref is the given value of DC voltage, and the per unit value is 1~1.2; ③ Combine the output value of the first proportional integrator (PI1) with the measured output side AC voltage US and current Id, and obtain the active power control value u _d of the inverter unit through the second proportional integrator (PI2). The specific formula as follows: u _d ＝k _p2 *(u _d0 -I _d )+k _i2 *∫(u _d0 -I _d )dt+U _S ④ Measure the AC current I _q on the output side and pass through the third proportional integrator (PI3) to obtain the reactive power control value u _q of the inverter unit. The specific formula is as follows: u _q =k _p3 *I _q +k _i3 *∫I _q dt; ⑤According to the reactive power control quantity u _q and active power control quantity u _d , after dq-abc Parker inverse transformation, the pulse width modulation PWM signal of the three-phase inverter unit is obtained: The output voltage of the conversion unit at the output side is adjusted. 6. The control method according to claim 4, characterized in that the input-side conversion unit control method comprises the following steps: Step 1, constant power control: Under constant power control, the constant power control is as follows: ① Given the control parameters of the fourth proportional integrator (PI4), the fifth proportional integrator (PI5), and the sixth proportional integrator (PI6): 1<k _p4 <100, 0.1<k _i4 <10, 1<k _p5 <100, 0.1<k _i5 <10, 1<k _p6 <100, 0.1<k _i6 <10, 1<k _p7 <100, 0.1<k _i7 <10, measure input side AC voltage u _s and AC current i _s , and thus get the input-side AC voltage amplitude U _S1 , the input-side AC current amplitudes I _d1 , I _q1 and the power angle θ ₂ between the input-side AC voltage and AC current, and calculate the active power P=U _S1 ×I _d1 , reactive power Q＝U _S1 ×I _q1 ; ② Set the given value of active power P _ref , control the difference between P _ref and the calculated P by the fourth proportional integrator (PI4), and calculate the intermediate control value u _d20 according to the following formula: u _d20 ＝k _p4 *(P _ref -P)+k _i4 *∫(P _ref -P)dt ③According to the intermediate control variable u _d20 output by the fourth proportional integrator (PI4), combined with the measured input side AC voltage U _S1 and current I _d1 , the control variable u _d2 of the inverter unit is obtained through the following formula: u _d2 ＝k _p5 *(u _d20 -I _d1 )+k _i5 *∫(u _d20 -I _d1 )dt+U _S1 ④ Set the given value of reactive power Q _ref , control the difference between Q _ref and the calculated reactive power Q through the sixth proportional integrator (PI6), and calculate the intermediate control quantity u _q20 according to the following formula: u _q20 ＝k _p6 *(Q _ref -Q)+k _i6 *∫(Q _ref -Q)dt ⑤ According to the output value of the sixth proportional integrator (PI6), combined with the measured input-side AC current I _q1 , after the seventh proportional-integral control (PI7), the control variable u _q2 of the inverter unit is calculated according to the following formula: u _q2 ＝k _p7 *(u _q20 -I _q1 )+k _i7 *∫(u _q20 -I _q1 )dt ⑥According to the control variables u _d2 and u _q2 , after dq-abc Parker inverse transformation, the pulse width modulation PWM signal of the three-phase inverter unit is obtained: Regulating the output voltage of the conversion unit at the input side; Step 2, select the constant current control, the constant current control is as follows: Given the active current value I _dref , in the above steps, u _d20 =I _dref ; Step 3, select the constant resistance control, the constant resistance control is as follows: Given a resistance reference value R _ref , in the above step 1, u _d20 =U _s1 /I _dref . 7. The control method according to claim 4, characterized in that the energy feedback optimization model function of the energy feedback optimization method: $<span\; class="notranslate">\; \&lsqb;</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; \&rsqb;</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; b</span>}\mathrm{<span\; class="notranslate">\; j</span>}\mathrm{<span\; class="notranslate">\; e</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; the\; s</span>}<span\; class="notranslate">\; (</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; D.</span>}\mathrm{<span\; class="notranslate">\; C</span>}}<span\; class="notranslate">\; -</span>{\stackrel{<span\; class="notranslate">\; \&OverBar;</span>}{\mathrm{<span\; class="notranslate">\; u</span>}}}_{\mathrm{<span\; class="notranslate">\; D.</span>}\mathrm{<span\; class="notranslate">\; C</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>$ in, is the average value of U _DC .