A static simulation device and design method for testing a pressure regulator protection function

Abstract

A kind of static simulation device and design method of voltage regulator protection function test, device includes AC / DC power supply, permanent magnet auxiliary exciter simulation device, main exciter simulation device, main motor simulation device, under frequency fault simulation switch, under frequency fault simulation switch, over frequency fault simulation switch, over over frequency fault simulation switch, under voltage fault simulation switch, over voltage fault simulation switch, power generation control circuit breaker.Permanent magnet auxiliary exciter simulation device and main motor simulation device use space vector pulse width modulation SVPWM to generate simulated permanent magnet auxiliary exciter three-phase voltage and main motor simulation three-phase voltage, the amplitude adjustment of output three-phase voltage is realized by changing the modulation depth of SVPWM, over frequency, over over frequency, under frequency, under under frequency etc. protection function test is carried out by permanent magnet auxiliary exciter simulation device, under voltage, over voltage etc. protection function test is carried out by the design of main motor simulation device, with the advantages of easy operation, light weight, low cost, suitable for the field of aviation three-stage generator system.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of generator testing, and is especially suitable for a three-stage generator system in aviation, and particularly relates to a static simulation device for testing the protection function of a voltage regulator and a design method. BACKGROUND

[0002] In the field of aviation, three-stage generator systems are widely used in main power sources driven by main engines, auxiliary power sources driven by auxiliary power devices, and emergency power sources driven by ram air turbines. A three-stage generator system is composed of a three-stage generator and a voltage regulator, and the voltage regulator is used to realize the voltage stabilization control of the three-stage generator and convert mechanical energy into electrical energy.

[0003] For safety considerations, various protection functions are usually provided in a three-stage generator system, and the most typical protection functions are over-frequency, over-over-frequency, under-frequency, under-under-frequency, over-voltage, and under-voltage protection functions. For over-frequency and over-over-frequency protection, the protection threshold frequency of over-frequency protection is slightly higher than the normal frequency, and the protection time is longer, while the protection threshold frequency of over-over-frequency protection is significantly higher than the normal frequency, and the protection time is shorter. The protection threshold and protection time of under-frequency and under-under-frequency protection are also similar to those of over-frequency and over-over-frequency, and the protection threshold frequency of under-frequency protection is slightly lower than the normal frequency, and the protection time is longer, while the protection threshold frequency of under-under-frequency protection is significantly lower than the normal frequency, and the protection time is shorter. For over-voltage, which is more dangerous, multiple over-voltage protection is usually provided, and as the protection threshold of each level of over-voltage protection increases, the action time of each level of over-voltage protection decreases, which has a clear anti-delay characteristic.

[0004] In order to ensure the accuracy of the protection threshold, the protection threshold of each voltage regulator needs to be set during the production and design process, and in order to verify the effectiveness of the protection function, the protection function of each voltage regulator needs to be tested before it is shipped. Adding a special test device to realize the protection function test of the voltage regulator can help improve the production efficiency of the voltage regulator.

[0005] The traditional protection function test of the voltage regulator includes two methods: joint test with a three-stage generator and test with a static device simulating a three-stage generator.

[0006] The joint test method with a three-stage generator has the following disadvantages:

[0007] 1) The test equipment requires high speed input from a three-stage generator by dragging a test bench, which requires high test equipment and high test cost;

[0008] 2) Over-frequency protection requires the three-stage generator to work in an extreme high-speed condition, and over-voltage protection requires the three-stage generator to output an extreme high voltage, which requires high mechanical and insulation performance of the three-stage generator, and may cause damage to the three-stage generator;

[0009] 3) The over-frequency and under-frequency protection action time is short, the speed requirement of the rotating speed regulation is high, and the response speed limit of the drag test table may be exceeded; when over-voltage protection is performed, the over-voltage fault condition is simulated by rapidly shedding load, and if the load characteristic of the three-stage generator is relatively hard, the over-voltage of the high-voltage protection point may not be simulated.

[0010] For the method of simulating a three-stage generator by using a static device for testing, the following deficiencies mainly exist:

[0011] 1) A general high-frequency power supply is usually used to simulate the permanent magnet auxiliary exciter and the main motor, and more test equipment is required, and the test cost is also high;

[0012] 2) When over-voltage testing is performed, the high-frequency power supply is switched between normal voltage and over-voltage by manual control, and due to the limited speed of manual operation, the action time is difficult to control within 0.2s, and the voltage regulator may be damaged due to the over-voltage time being too long;

[0013] 3) The frequency change and voltage change rate of the general high-frequency power supply are limited, and usually 100ms is required to complete the switching, and the over-frequency or under-frequency protection may be triggered in advance, resulting in that the over-frequency and under-frequency protection functions cannot be tested, and the over-voltage protection of a lower protection voltage threshold may be triggered in advance, resulting in that the over-voltage protection function of a higher protection voltage threshold cannot be tested. SUMMARY

[0014] To solve the above technical problems, the application provides a static simulation device for testing the protection function of a voltage regulator and a design method.

[0015] The application is implemented by the following technical solutions.

[0016] The static simulation device for testing the protection function of a voltage regulator provided by the application comprises an AC / DC power supply, a permanent magnet auxiliary exciter simulation device, a main exciter simulation device, a main motor simulation device, under-under-frequency fault simulation switches S LLF , under-frequency fault simulation switches S LF , over-frequency fault simulation switches S OF , over-over-frequency fault simulation switches S OOF , under-voltage fault simulation switches S LV , a plurality of over-voltage fault simulation switches S OV1 ~S OVn and a generator control circuit breaker GCB; the AC input ends L and N of the AC / DC power supply are connected with 220V single-phase commercial power, and the output positive and negative poles of the AC / DC power supply are connected with the input positive and negative poles of the permanent magnet auxiliary exciter simulation device and the main motor simulation device, respectively; the under-under-frequency fault simulation switches S LLF , the under-frequency fault simulation switches S LF, over-frequency fault simulation switch S OF and over over-frequency fault simulation switch S OOF One end of the permanent magnet auxiliary exciter simulation device is connected with the input negative pole of the permanent magnet auxiliary exciter simulation device, and the other end is connected with the input interface of the permanent magnet auxiliary exciter simulation device, the A, B and C output three-phase voltage v PMG_A , v PMG_B and v PMG_C are connected with the voltage regulator, the F+ and F- of the main exciter simulation device are connected with the voltage regulator, the under-voltage fault simulation switch S LV and a plurality of over-voltage fault simulation switches S OV1 ~ S OVn One end of the main motor simulation device is connected with the input negative pole of the main motor simulation device, and the other end is connected with the input interface of the main motor simulation device, the A, B and C output three-phase voltage v M_A , v M_B and v M_C of the main motor simulation device, and the input end of the generator control circuit breaker GCB is connected with the A, B and C end of the main motor simulation device, the output end of the generator control circuit breaker GCB outputs three-phase voltage v o_A , v o_B and v o_C , and the control end of the generator control circuit breaker GCB is connected with the driving signal G o output by the voltage regulator.

[0017] Further, the permanent magnet auxiliary exciter simulation device comprises an inverter A, a filter A and a control circuit A, the inverter A comprises power tubes Q A1 ~ Q A6 , the filter A comprises inductors L Aa , L Ab , L Ac and capacitors C Aa , C Ab , C Ac ; the input positive pole of the permanent magnet auxiliary exciter simulation device is connected with the drain of the power tube Q A1 , the drain of the power tube Q A3 and the drain of the power tube Q A5 , and the input negative pole is connected with the source of Q A2 , the source of Q A4 and the source of Q A6 ; one end of the inductor L Aa is connected with the source of Q A1 and the drain of Q A2 , the other end of the inductor L Aa is connected with the output A end, one end of the inductor L Ab is connected with the source of Q A3 and the drain of Q A4 , and the other end of the inductor L AbThe other end is connected to the output B terminal, and the inductor L Ac One end and Q A5 source and Q A6 The drain connection, inductor L Ac The other end is connected to the output C terminal; capacitor C Aa C Ab and C Ac One end is connected to the output terminals A, B, and C respectively, and capacitor C Aa C Ab and C Ac The other end is connected together; the input interface of the control circuit A is respectively connected to the under-frequency fault simulation switch S. LLF Underfrequency fault simulation switch S LF Over-frequency fault simulation switch S OF and over-frequency fault simulation switch S OOF The connection is made so that the output drive signal G of the control circuit A is connected. A1 ~G A6 With power transistor Q respectively A1 ~Q A6 The gate connection.

[0018] Furthermore, the main exciter simulation device includes an ammeter S. I Resistance R B and inductor L B The F+ terminal of the main exciter simulation device is connected in series with an ammeter S. I Resistance R B Inductor L B Finally, it reaches the F-end.

[0019] Furthermore, the main motor simulation device includes an inverter B, a filter B, a control circuit B, a DC blocking capacitor, a step-up transformer, and a voltage detection circuit; the inverter B includes a power transistor Q. B1 ~Q B6 Filter B includes inductor L Ba L Bb L Bc and capacitor C Ba C Bb C Bc DC blocking capacitors include capacitor C. Ba1 C Bb1 C Bc1 The step-up transformer includes transformer T. a T b and T c The positive input terminal of the main motor simulation device is connected to the power transistor Q. B1 drain, Q B3 The drain and Q B5 The drain is connected, and the input negative terminal is connected to the power transistor Q.B2 The source, Q B4 source and Q B6 Source connection; power transistor Q B1 source and Q B2 The drain connection of the power transistor Q B1 Source and Q B2 The drain connection point is connected via inductor L Ba Capacitor C Ba1 With transformer T a Connect the input terminal with the same name, power transistor Q B3 source and Q B4 Drain connection, Q B3 Source and Q B4 The drain connection point is connected via inductor L Bb Capacitor C Bb1 With transformer T b Connect the input terminals with the same name, Q B5 source and Q B6 Drain connection, Q B5 Source and Q B6 The drain connection point is connected via inductor L Bc Capacitor C Bc1 With transformer T c Connect the input terminals with the same name; capacitor C Ba One end is connected to inductor L Ba and capacitor C Ba1 Connection, capacitor C Bb One end is connected to inductor L Bb and capacitor C Bb1 Connection, capacitor C Bc One end is connected to inductor L Bc and capacitor C Bc1 Connection, capacitor C Ba C Bb and C Bc The other end is connected together; the transformer's T a T b and T c The input terminals with different names are connected to each other, and the transformer's T... a T b and T c The output terminals of the transformer are connected to each other, and the transformer's T... a T b and T c The output terminals are connected to output terminals A, B, and C respectively. Output terminals A, B, and C are connected to the input terminals of the voltage detection circuit. The effective value V of the phase voltage output by the voltage detection circuit is connected to the control circuit B. The input interface of the control circuit B is connected to the undervoltage fault simulation switch S. LV and multiple overvoltage fault simulation switches S OV1 ~S OVnConnect, control circuit B output drive signal G B1 ~ G B6 Respectively with power tube Q B1 ~ Q B6 Gate connection.

[0020] A design method of static simulation device for testing the protection function of voltage regulator, comprising the following steps:

[0021] Step 1, the permanent magnet auxiliary exciter simulation device, the main exciter simulation device and the main motor simulation device are used to simulate the permanent magnet auxiliary exciter, the main exciter and the main motor in the three-stage generator respectively;

[0022] Step 2, the permanent magnet auxiliary exciter simulation device and the main motor simulation device adopt space vector pulse width modulation (SVPWM) to generate simulated three-phase voltage v PMG and the main motor simulation three-phase voltage v M The fundamental frequency of SVPWM is used to realize the frequency regulation of the output three-phase voltage, and the modulation depth of SVPWM is changed to realize the amplitude regulation of the output three-phase voltage;

[0023] Step 3, when simulating normal operation, the under-under frequency fault simulation switch S LLF , the under frequency fault simulation switch S LF , the over frequency fault simulation switch S OF and the over-over frequency fault simulation switch S OOF are all disconnected, the permanent magnet auxiliary exciter simulation device outputs three-phase voltage v PMG of normal frequency, the under-voltage fault simulation switch S LV , each stage over-voltage fault simulation switch S OV1 , S OV2 …S OVn are all disconnected, and the main motor simulation device outputs normal three-phase voltage v M ;

[0024] Step 4, the over frequency, over-over frequency, under frequency and under-under frequency protection function test is carried out through the permanent magnet auxiliary exciter simulation device design;

[0025] Step 5, the under-voltage and over-voltage protection function test is carried out through the main motor simulation device design.

[0026] Further, the permanent magnet auxiliary exciter simulation device design in step 4 comprises the following steps:

[0027] Step 401, closing S LLF , S LF , S OF or S OOF , so that the permanent magnet auxiliary exciter simulation device outputs over-over frequency, over frequency, under frequency or under-under frequency three-phase voltage vPMG ;

[0028] Step 402, switch the normal frequency output by the permanent magnet auxiliary exciter simulation device to an abnormal frequency, and increase the voltage amplitude output by the inverter A;

[0029] Step 403, set the switching frequency of the SVPWM to 20 times the highest frequency output by the inverter A, and design the cutoff frequency of the filter A to be 2 times the highest frequency output by the inverter A, so as to filter out the high-frequency components in the SVPWM through the filter A and leave the fundamental frequency components.

[0030] Further, the main motor simulation device in step 5 is designed, including the following steps:

[0031] Step 501, close S LV , so that the main motor simulation device outputs the three-phase voltage v M ;

[0032] Step 502, when any one of S OV1 , S OV2 …S OVn is closed, the main motor simulation device outputs the three-phase voltage v p1 with the effective value of V p2 , V pn …V M respectively, and restores the normal voltage V after maintaining the overvoltage t p1 , t p2 …t pn respectively, and maintains the overvoltage t p1 , t p2 …t pn is set to 1.3 times of t1, t2…t n corresponding to the protection time;

[0033] Step 503, set the switching frequency of the SVPWM to 25 times the highest frequency output by the inverter B, and design the cutoff frequency of the filter A to be 3 times the highest frequency output by the inverter A, so as to filter out the high-frequency components in the SVPWM through the filter B and leave the fundamental frequency components.

[0034] Further, in step 5, when the main motor outputs abnormal voltage simulation, open-loop control is adopted to ensure the rapidity of voltage regulation.

[0035] Further, in step 5, when the main motor outputs normal voltage simulation, closed-loop voltage control is adopted to ensure the accuracy of the output voltage.

[0036] Further, the abnormal voltage simulation includes under-voltage simulation and over-voltage simulation.

[0037] The beneficial effects of the present application are that:

[0038] 1. The static simulation device and design method for testing the protection function of the voltage regulator are proposed, which are suitable for the field of aviation three-phase generator system.

[0039] 2. Compared with the method of testing with three-phase generator, the method overcomes the shortcomings of high testing equipment requirements, high testing costs, possible mechanical and insulation damage to the three-phase generator, over-frequency and under-frequency protection action time exceeding the speed regulation limit of the test bench, and the over-voltage protection function of the high-voltage protection point may not be tested.

[0040] 3. Compared with the method of testing with static device simulation three-phase generator, the method overcomes the shortcomings of high testing equipment requirements, high testing costs, long manual normal voltage and over-voltage switching time which may cause damage to the voltage regulator, and the frequency and voltage change rate of the high-frequency power supply is limited, which leads to the over-frequency, under-frequency and high protection voltage threshold over-voltage protection cannot be tested.

[0041] 4. The inverters A and B in the permanent magnet auxiliary exciter simulation device and the main motor simulation device can use the same software and hardware structure, which has high universality.

[0042] 5. When switching from normal frequency to abnormal frequency, the voltage amplitude output by inverter A is also increased, which facilitates the use of oscilloscope trigger function to read the protection delay time.

[0043] 6. After closing the over-voltage test switch, the over-voltage time thx, x = 1, 2…n is controlled by the program, and after exceeding thx, the normal voltage is forced to restore, which can avoid the damage to the voltage regulator caused by too long over-voltage time.

[0044] 7. The static simulation device is mainly used to provide test voltage signals, and has the advantages of small size, light weight and low cost.

[0045] 8. Inverters A and B use high switching frequency, so that filter A and filter B can use high cutoff frequency and small on-resistance, ensuring the rapidity of frequency regulation and the small impact of output voltage on load.

[0046] 9. When simulating the output abnormal voltage of the main motor, open-loop control is used to ensure the rapidity of voltage regulation.

[0047] 10. When simulating the output normal voltage of the main motor, closed-loop voltage control is used to ensure the accuracy of the output voltage. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 : Structure block diagram of three-phase generator system with AC output;

[0049] Figure 2Structure block diagram of static simulation device for testing voltage regulator protection function

[0050] Figure 3 Circuit diagram of permanent magnet auxiliary exciter simulation device

[0051] Figure 4 Circuit diagram of main exciter simulation device

[0052] Figure 5 Circuit diagram of main motor simulation device

[0053] Figure 6 Control principle diagram of permanent magnet auxiliary exciter simulation device

[0054] Figure 7 Principle diagram of overvoltage inverse time delay protection

[0055] Figure 8 Control principle diagram of main motor simulation device

[0056] Figure 9 Principle diagram of traditional protection function test DETAILED DESCRIPTION

[0057] The technical solutions of the present application are described further below, but the scope of protection is not limited to the description.

[0058] Figure 1 The structure block diagram of a three-stage generator system with AC output is shown, which is suitable for 115V, 400Hz constant frequency AC and 115V, 360Hz-800Hz variable frequency AC power supply system. The three-stage generator system comprises a three-stage generator and a voltage regulator. The three-stage generator comprises a permanent magnet auxiliary exciter, a main exciter, a main motor and a rotating rectifier. The voltage regulator comprises a rectifier bridge A, a voltage regulating circuit, a control circuit, a voltage detector A and a voltage detector B.

[0059] During power generation, the engine drives the permanent magnet auxiliary exciter rotor to rotate. The rotating permanent magnet induces three-phase AC v PMG in the auxiliary exciter stator winding W PMG . The AC v EE is rectified by the rotating rectifier to provide DC current I F for the voltage regulating circuit. The rotating main exciter rotor armature winding W EE cuts the stator magnetic field to induce three-phase AC v EM . The AC v EM is rectified by the rotating rectifier to provide DC V R for the main motor excitation winding W EE to provide excitation current, which forms a rotating magnetic field on the main motor rotor. The rotating magnetic field induces three-phase AC v MM in the main motor stator armature winding W M, the voltage regulator keeps the three-phase alternating voltage v M stable by adjusting the excitation current I F .

[0060] The interface of the voltage regulator to the outside includes the following aspects:

[0061] 1) The output three-phase voltage v PMG of the permanent magnet auxiliary exciter, including the A, B and C phase voltages v PMG_A , v PMG_B and v PMG_C , the voltage regulator first obtains the output frequency of the permanent magnet auxiliary exciter according to the three-phase voltage v PMG , and then obtains the working frequency of the main motor according to the pole pair numbers of the permanent magnet auxiliary exciter and the main motor, thereby realizing the over-frequency, over-over-frequency, under-frequency and under-under-frequency protection functions;

[0062] 2) The excitation winding interface of the main exciter, which is used to provide the excitation current for the main exciter, and when a fault occurs, the fault protection purpose is achieved by breaking the power control relay GCR, and by monitoring the presence or absence of the excitation current, the working normal or fault protection state can be determined;

[0063] 3) The output three-phase voltage sampling interface of the main motor, through which the output three-phase voltage v M of the main motor is obtained by voltage detection A, and the three-phase voltage v M includes the A, B and C phase voltages v M_A , v M_B and v M_C , and the effective value V of the phase voltage is calculated according to the three-phase voltage v M , which is used as the basis for overvoltage and undervoltage fault protection;

[0064] 4) The drive signal G o interface of the power control circuit breaker GCB, the input and output ends of the GCB are connected with the output three-phase voltage v M of the main motor and the alternating output v o , the alternating output v o includes the A, B and C phase voltages v o_A , v o_B and v o_C , and when the power is normally generated or the fault protection is performed, the GCB is closed or opened by the drive signal G o , that is, the alternating output v o = v M or v o = 0, and by monitoring the presence or absence of the alternating output v o , the working normal or fault protection state can be determined.

[0065] The static simulation device for testing the protection function of the voltage regulator is to simulate the rotating three-stage generator by the static device to realize the test of the over frequency, over over frequency, under frequency, under under frequency, over voltage and under voltage protection functions. The external interface of the static simulation device for testing the protection function of the voltage regulator needs to be compatible with the interfaces of the above-mentioned four types of voltage regulators.

[0066] Figure 2 The static simulation device for testing the protection function of the voltage regulator is shown in the structure block diagram. The static simulation device for testing the protection function of the voltage regulator includes an AC / DC power supply, a permanent magnet auxiliary exciter simulation device, a main exciter simulation device, a main motor simulation device, an under under frequency fault simulation switch S LLF , an under frequency fault simulation switch S LF , an over frequency fault simulation switch S OF , an over over frequency fault simulation switch S OOF , an under voltage fault simulation switch S LV , and a plurality of over voltage fault simulation switches S OV1 , S OV2 …S OVn , and a generator control circuit breaker GCB. The AC input terminals L and N of the AC / DC power supply are connected with the 220V single-phase commercial power supply. The positive and negative output terminals of the AC / DC power supply are connected with the input positive and negative terminals of the permanent magnet auxiliary exciter simulation device and the main motor simulation device respectively. One end of the under under frequency fault simulation switch S LLF , the under frequency fault simulation switch S LF , the over frequency fault simulation switch S OF , and the over over frequency fault simulation switch S OOF is connected with the input negative terminal of the permanent magnet auxiliary exciter simulation device, and the other end is connected with the input interface of the permanent magnet auxiliary exciter simulation device. The A, B and C output three-phase voltages v PMG_A , v PMG_B and v PMG_C of the permanent magnet auxiliary exciter simulation device are connected with the voltage regulator. The F+ and F- of the main exciter simulation device are connected with the voltage regulator. One end of the under voltage fault simulation switch S LV and the plurality of over voltage fault simulation switches S OV1 , S OV2 …S OVn is connected with the input negative terminal of the main motor simulation device, and the other end is connected with the input interface of the main motor simulation device. The A, B and C output three-phase voltages v M_A , v M_B and v M_C of the main motor simulation device are connected with the GCB. The input terminals of the GCB are connected with the A, B and C terminals of the main motor simulation device. The output terminals of the GCB output the three-phase voltages v o_A , v o_B and v o_C . The control terminal of the GCB is connected with the driving signal G oConnection structure.

[0067] Figure 3 The permanent magnet auxiliary exciter simulation device is shown, which comprises an inverter A, a filter A and a control circuit A. A1 ~ Q A6 The filter A comprises an inductor L Aa , L Ab , L Ac and a capacitor C Aa , C Ab , C Ac ; the input positive pole is connected with the drain of Q A1 , the drain of Q A3 and the drain of Q A5 , the input negative pole is connected with the source of Q A2 , the source of Q A4 and the source of Q A6 , one end of the inductor L Aa is connected with the source of Q A1 and the drain of Q A2 , the other end of the inductor L Aa is connected with the output A end, one end of the inductor L Ab is connected with the source of Q A3 and the drain of Q A4 , the other end of the inductor L Ab is connected with the output B end, one end of the inductor L Ac is connected with the source of Q A5 and the drain of Q A6 , the other end of the inductor L Ac is connected with the output C end, one end of the capacitor C Aa , C Ab and C Ac is connected with the output A, B and C end respectively, the other end of the capacitor C Aa , C Ab and C Ac is connected with each other, the input interface of the control circuit A is connected with the under-frequency fault simulation switch S LLF , the under-frequency fault simulation switch S LF , the over-frequency fault simulation switch S OF and the over-frequency fault simulation switch S OOF respectively, the control circuit A outputs the driving signals G A1 ~ G A6 which are connected with the gate of Q A1 ~ Q A6 respectively.

[0068] Figure 4 The main exciter simulation device is shown, which comprises an ammeter S IResistance R B and inductor L B It is from the F+ terminal through the ammeter S I Resistance R B Inductor L B It is connected to the F-end.

[0069] resistor R B and inductor L B The values ​​of are respectively related to the stator winding W of the main exciter. EE The resistance and inductance values ​​are kept consistent.

[0070] Figure 5 The diagram shows a main motor simulation device, which includes an inverter B, a filter B, a control circuit B, an isolation capacitor, a step-up transformer, and a voltage detection circuit. The inverter B includes a power transistor Q. B1 ~Q B6 Filter B includes inductor L Ba L Bb L Bc and capacitor C Ba C Bb C Bc DC blocking capacitors include C Ba1 C Bb1 C Bc1 The step-up transformer includes T a T b and T c ; is caused by the positive input and Q B1 drain, Q B3 Drain and Q B5 The drain connection is such that the negative input terminal is connected to Q. B2 The source, Q B4 the source and Q B6 The source connection, Q B1 the source and Q B2 Drain connection, Q B1 Source and Q B2 The drain connection point is connected via inductor L Ba Capacitor C Ba1 With transformer T a Connect the input terminals with the same name, Q B3 the source and Q B4 Drain connection, Q B3 Source and Q B4 The drain connection point is connected via inductor L Bb Capacitor C Bb1 With transformer T b Connect the input terminals with the same name, Q B5 the source and Q B6 Drain connection, Q B5 Source and QB6 The connection point of the drain is connected through an inductor L Bc , a capacitor C Bc1 The input same name end of the transformer T c is connected, one end of the capacitor C Ba is connected with the inductor L Ba and the capacitor C Ba1 , one end of the capacitor C Bb is connected with the inductor L Bb and the capacitor C Bb1 , one end of the capacitor C Bc is connected with the inductor L Bc and the capacitor C Bc1 , the other end of the capacitor C Ba , C Bb and C Bc is connected with each other, the input different name end of the transformer T a , T b and T c is connected with each other, the output different name end of the transformer T a , T b and T c is connected with each other, the output same name end of the transformer T a , T b and T c is connected with the output A, B and C end respectively, the output A, B and C end is connected with the input end of the voltage detection circuit, the voltage detection circuit output phase voltage effective value V is connected with the control circuit B, the input interface of the control circuit B is connected with the under-voltage fault simulation switch S LV , each stage over-voltage fault simulation switch S OV1 , S OV2 …S OVn respectively, the control circuit B output drive signal G B1 ~ G B6 is connected with the gate of the power tube Q B1 ~ Q B6 respectively to constitute.

[0071] As can be seen from Figure 4 and Figure 5 , the same hardware and software structure is adopted in the inverter A and B of the permanent magnet auxiliary exciter simulation device and the main motor simulation device, and the universality is higher.

[0072] The design method of the static simulation device for testing the protection function of the voltage regulator comprises the following steps:

[0073] Step 1, respectively through the permanent magnet auxiliary exciter simulation device, the main exciter simulation device and the main motor simulation device to simulate the permanent magnet auxiliary exciter, the main exciter and the main motor in the three-stage generator;

[0074] Step 2, the permanent magnet auxiliary exciter simulation device and the main motor simulation device adopt space vector pulse width modulation (SVPWM) to generate simulated permanent magnet auxiliary exciter three-phase voltage v PMG and the main motor simulation three-phase voltage v M The frequency regulation of the output three-phase voltage is realized by the fundamental frequency of SVPWM, and the amplitude regulation of the output three-phase voltage is realized by changing the modulation depth of SVPWM.

[0075] Step 3, during normal working simulation, the under-frequency fault simulation switch S LLF , the under-frequency fault simulation switch S LF , the over-frequency fault simulation switch S OF and the over-frequency fault simulation switch S OOF are all disconnected, and the permanent magnet auxiliary exciter simulation device outputs three-phase voltage v PMG of normal frequency, the under-voltage fault simulation switch S LV , each stage of the over-voltage fault simulation switch S OV1 , S OV2 …S OVn are all disconnected, and the main motor simulation device outputs normal three-phase voltage v M .

[0076] Step 4, the over-frequency, over-over-frequency, under-frequency, under-under-frequency, etc. protection function test is carried out through the permanent magnet auxiliary exciter simulation device design.

[0077] Step 5, the under-voltage, over-voltage, etc. protection function test is carried out through the main motor simulation device design.

[0078] The permanent magnet auxiliary exciter simulation device design of step 4 includes the following steps:

[0079] Step 401, when S LLF , S LF , S OF or S OOF is closed, the permanent magnet auxiliary exciter simulation device outputs three-phase voltage v PMG of over-over-frequency, over-frequency, under-frequency or under-under-frequency.

[0080] Step 402, when switching from normal frequency to abnormal frequency, the voltage amplitude output by inverter A is also increased at the same time.

[0081] Step 403, the switching frequency of SVPWM is set to 20 times the highest frequency output by inverter A, and the cutoff frequency of filter A is designed to be 2 times the highest frequency output by inverter A, so as to filter out the high frequency component in SVPWM through filter A and leave the fundamental component.

[0082] In combination with Figure 6The control principle of the permanent magnet auxiliary exciter simulator shown will be used to explain step 4 in detail. Whether the over-frequency, over-over-frequency, under-frequency, and under-under-frequency protection functions are normal, or whether the protection time is normal, can be checked by simultaneously reading the A-phase voltage V output by the permanent magnet auxiliary exciter simulator using an oscilloscope. PMG_A and the A-phase voltage v output by GCB o_A To obtain it. Taking over-frequency protection testing as an example, S in the figure OF Since 0 to 1 represents the overfrequency fault simulation switch S OF The frequency switches from open to closed. Because switching from a normal frequency to an abnormal frequency also increases the voltage amplitude of inverter A's output, the oscilloscope's trigger level can be set between the normal voltage peak and the abnormal voltage peak. This will lock a segment of the waveform before and after the frequency switch, specifically the A-phase voltage V. PMG_A The amplitude rises to phase A voltage v o_A The time that disappeared t OF This is the actual measured over-frequency protection action time.

[0083] Depend on Figure 6 According to relevant analysis, when switching from normal frequency to abnormal frequency, the voltage amplitude of inverter A output is also increased, making it easier to read the protection delay time using the oscilloscope trigger function.

[0084] The design of the main motor simulation device in step 5 includes the following steps:

[0085] Step 501, when S is closed LV When this occurs, the motor simulation device outputs an undervoltage three-phase voltage v. M ;

[0086] Step 502, when S OV1 S OV2 …S OVn When any one of them is closed, the main motor simulation device outputs an effective value of V. p1 V p2 …V pn Three-phase voltage v M and maintain overpressure t respectively p1 t p2 …t pn After the voltage returns to normal (V), the overvoltage (t) is maintained. p1 t p2 …t pn Set to the corresponding protection time t1, t2...t n 1.3 times;

[0087] Step 503: Set the switching frequency of SVPWM to 25 times the highest output frequency of inverter B, and design the cutoff frequency of filter A to 3 times the highest output frequency of inverter A. Use filter B to filter out the high-frequency components in SVPWM and leave the fundamental frequency components.

[0088] In step 5, when simulating abnormal voltage output of the main motor, open-loop control is used to ensure rapid voltage regulation, while when simulating normal voltage output of the main motor, closed-loop voltage control is used to ensure the accuracy of the output voltage.

[0089] Combination Figure 7 The overvoltage inverse delay protection principle and Figure 8 The control principle of the main motor simulation device shown will be explained in detail below for step 5. Figure 7 The effective value of the intermediate voltage V is compared with the rated voltage V N The higher the value, the shorter the protection response time. To better approximate the inverse delay protection curve, multiple overvoltage fault points are usually set, such as (V... p1 、t1), (V p2 、t2)…(V pn t n ), protection threshold voltage V p1 V p2 …V pn Gradually decrease, slowly approaching a voltage slightly higher than the stable voltage V. N Status, protection time t1, t2...t n Gradually increasing.

[0090] Figure 8 The diagram shows the control principle of the main motor simulation device. Whether the undervoltage and overvoltage protection functions properly or whether the protection time is normal can be determined by simultaneously reading the A-phase voltage v output by the main motor simulation device. M_A and the A-phase voltage v output by GCB o_A To obtain. Using the overvoltage protection point (V) p1 t 1) Taking the test as an example, S in the figure OV1 Since 0 to 1 represents the first-level overvoltage fault simulation switch S OV1 Switching from open to closed state, in S OV1 After closing, v M_A It will be due to the rated voltage V N Switch to overvoltage value V p1 and maintenance time t h1 The oscilloscope's trigger level can be set between the normal voltage peak and the abnormal voltage peak. During overvoltage switching, it will lock a segment of the waveform before and after the switching instant, such as the A-phase voltage V. M_A The amplitude rises to phase A voltage v o_A The time that disappeared t OV1The first stage overvoltage fault protection action time is measured.

[0091] In step 502, after closing the overvoltage test switch, the overvoltage time t hx , x = 1, 2…n, after t hx , the normal voltage is forced to be restored to avoid overvoltage time being too long and causing damage to the voltage regulator.

[0092] The static simulation device is mainly used for providing test voltage signals, and has the advantages of small power, small size, light weight and low cost. The inverter A and the inverter B adopt a high switching frequency, so that the filter A and the filter B can adopt a high cut-off frequency and a small on-resistance, thereby ensuring the rapidity of frequency regulation and the small influence of the output voltage on the load.

[0093] Compared with the method of performing joint test with a three-stage generator, the static simulation device and the design method for testing the protection function of the voltage regulator overcome the problems of high test equipment requirement, high test cost, possible mechanical and insulation damage to the three-stage generator, over-frequency and under-frequency protection action time exceeding the speed regulation limit of the test platform, and overvoltage protection function of the high-voltage protection point being unable to be tested.

[0094] Figure 9 The traditional protection function test principle is shown. In the frequency protection function test of over-frequency, over over-frequency, under-frequency and under under-frequency, the switch S v is always connected to the normal voltage analog power supply side, so that the main motor simulates the three-phase voltage v M as the normal rated voltage V N . The frequency change of the three-phase voltage v PMG is simulated by switching the switch S f from the normal frequency analog power supply to the abnormal frequency analog power supply. In the voltage protection function test of under-voltage and over-voltage, the switch S f is always connected to the normal frequency analog power supply side, so that the permanent magnet auxiliary exciter simulates the voltage v PMG as the normal frequency. The voltage change of the three-phase voltage v M is simulated by switching the switch S V from the normal voltage analog power supply to the abnormal voltage analog power supply. The test method of the frequency protection and the voltage protection shows that the traditional method of testing the three-stage generator by using the static device for simulation at least needs three high-frequency power supplies to complete the test.

[0095] Compared with the method of testing the three-stage generator by using static device simulation, the proposed static simulation device and design method for testing the voltage regulator protection function overcomes the shortcomings of high testing equipment requirements, high testing costs, long manual normal voltage and over-voltage switching time which may cause damage to the voltage regulator, limited frequency and voltage change rate of high-frequency power supply which leads to over-frequency, under-frequency and over-voltage protection of high protection voltage threshold which cannot be tested.

Claims

1. A static simulation device for testing the protection function of a voltage regulator, characterized in that: Includes AC / DC power supply, permanent magnet auxiliary exciter simulation device, main exciter simulation device, main motor simulation device, and under-frequency fault simulation switch S. LLF Underfrequency fault simulation switch S LF Over-frequency fault simulation switch S OF Over-frequency fault simulation switch S OOF Undervoltage fault simulation switch S LV Multiple overvoltage fault simulation switches S OV1 ~S OVn And the power generation control circuit breaker (GCB); The AC input terminals L and N of the AC / DC power supply are connected to a 220V single-phase mains power supply, and the positive and negative output terminals of the AC / DC power supply are connected to the positive and negative input terminals of the permanent magnet auxiliary exciter simulation device and the main motor simulation device, respectively; the under-frequency fault simulation switch S LLF Underfrequency fault simulation switch S LF Over-frequency fault simulation switch S OF and over-frequency fault simulation switch S OOF One end is connected to the negative input terminal of the permanent magnet auxiliary exciter simulator, and the other end is connected to the input interface of the permanent magnet auxiliary exciter simulator. The A, B, and C outputs of the permanent magnet auxiliary exciter simulator are three-phase voltages. v PMG_A , v PMG_B and v PMG_C Connected to the voltage regulator, the F+ and F- terminals of the main exciter simulation device are connected to the voltage regulator, and the undervoltage fault simulation switch S... LV and multiple overvoltage fault simulation switches S OV1 ~S OVn One end is connected to the negative input terminal of the main motor simulation device, and the other end is connected to the input interface of the main motor simulation device. The A, B, and C outputs of the main motor simulation device are three-phase voltages. v M_A , v M_B and v M_C The input terminals of the generator control circuit breaker GCB are connected to terminals A, B, and C of the main motor simulation device, and the output terminals of the generator control circuit breaker GCB output three-phase voltage. v o_A , v o_B and v o_C The control terminal of the power generation control circuit breaker GCB and the drive signal output by the voltage regulator G o connect.

2. The static simulation device for testing the protection function of a voltage regulator as described in claim 1, characterized in that: The permanent magnet auxiliary exciter simulation device includes an inverter A, a filter A, and a control circuit A. The inverter A includes a power transistor Q. A1 ~Q A6 The filter A includes an inductor. L Aa , L Ab , L Ac and capacitor C Aa , C Ab , C Ac ; The positive input terminal of the permanent magnet auxiliary exciter simulation device is connected to the power transistor Q. A1 drain, power transistor Q A3 The drain and power transistor Q A5 The drain connection is such that the negative input terminal is connected to Q. A2 The source, Q A4 the source and Q A6 The source connection; inductance L Aa One end and Q A1 the source and Q A2 Drain connection, inductor L Aa The other end is connected to output A, and the inductor L Ab One end and Q A3 the source and Q A4 Drain connection, inductor L Ab The other end is connected to the output B terminal, inductor L Ac One end and Q A5 the source and Q A6 Drain connection, inductor L Ac The other end is connected to the output C terminal; capacitor C Aa , C Ab and C Ac One end is connected to the output terminals A, B, and C respectively, and the capacitor C Aa , C Ab and C Ac The other end is connected together; the input interface of the control circuit A is respectively connected to the under-frequency fault simulation switch S. LLF Underfrequency fault simulation switch S LF Over-frequency fault simulation switch S OF and over-frequency fault simulation switch S OOF The connection is made to the output drive signal of the control circuit A. G A1 ~ G A6 With power transistor Q respectively A1 ~Q A6 The gate connection.

3. The static simulation device for testing the voltage regulator protection function as described in claim 1, characterized in that: The main exciter simulation device includes an ammeter S I ,resistance R B and inductor L B The F+ terminal of the main exciter simulation device is connected in series with an ammeter S. I ,resistance R B ,inductance L B Finally, it reaches the F-end.

4. The static simulation device for testing the protection function of a voltage regulator as described in claim 1, characterized in that: The main motor simulation device includes an inverter B, a filter B, a control circuit B, a DC blocking capacitor, a step-up transformer, and a voltage detection circuit. The inverter B includes a power transistor Q. B1 ~Q B6 Filter B includes an inductor. L Ba , L Bb , L Bc and capacitor C Ba , C Bb , C Bc DC blocking capacitors include capacitors C Ba1 , C Bb1 , C Bc1 The step-up transformer includes transformer T. a T b and T c The positive input terminal of the main motor simulation device is connected to the power transistor Q. B1 drain, Q B3 The drain and Q B5 The drain is connected, and the input negative terminal is connected to the power transistor Q. B2 The source, Q B4 the source and Q B6 Source connection; power transistor Q B1 the source and Q B2 The drain connection of the power transistor Q B1 Source and Q B2 The drain connection point is connected via an inductor L Ba ,capacitance C Ba1 With transformer T a Connect the input terminal with the same name, power transistor Q B3 the source and Q B4 Drain connection, Q B3 Source and Q B4 The drain connection point is connected via an inductor L Bb ,capacitance C Bb1 With transformer T b Connect the input terminals with the same name, Q B5 the source and Q B6 Drain connection, Q B5 Source and Q B6 The drain connection point is connected via an inductor L Bc ,capacitance C Bc1 With transformer T c Connect the input terminals with the same name; capacitor C Ba One end is connected to the inductor L Ba and capacitor C Ba1 Connection, capacitor C Bb One end is connected to the inductor L Bb and capacitor C Bb1 Connection, capacitor C Bc One end is connected to the inductor L Bc and capacitor C Bc1 Connection, capacitor C Ba , C Bb and C Bc The other end is connected together; the transformer's T a T b and T c The input terminals with different names are connected to each other, and the transformer's T... a T b and T c The output terminals of the transformer are connected to each other, and the transformer's T... a T b and T c The corresponding output terminals are connected to output terminals A, B, and C respectively. Output terminals A, B, and C are then connected to the input terminals of the voltage detection circuit, which outputs the effective value of the phase voltage. V Connected to control circuit B, the input interface of control circuit B is connected to undervoltage fault simulation switch S. LV and multiple overvoltage fault simulation switches S OV1 ~S OVn Connect and control circuit B to output drive signal G B1 ~ G B6 With power transistor Q respectively B1 ~Q B6 The gate connection.

5. The design method of the static simulation device for testing the protection function of a voltage regulator as described in any one of claims 1-4, characterized in that, Includes the following steps: Step 1: Simulate the permanent magnet auxiliary exciter, main exciter, and main motor in a three-stage generator using a permanent magnet auxiliary exciter simulation device, a main exciter simulation device, and a main motor simulation device, respectively. Step 2: The permanent magnet auxiliary exciter simulation device and the main motor simulation device use space vector pulse width modulation (SVPWM) to generate the three-phase voltage of the simulated permanent magnet auxiliary exciter. v PMG Simulated three-phase voltage of the main motor v M The frequency regulation of the output three-phase voltage is achieved by using the fundamental frequency of SVPWM, and the amplitude regulation of the output three-phase voltage is achieved by changing the modulation depth of SVPWM. Step 3, during normal operation simulation, the under-frequency fault simulation switch S LLF Underfrequency fault simulation switch S LF Over-frequency fault simulation switch S OF and over-frequency fault simulation switch S OOF All phases are disconnected, and the permanent magnet auxiliary exciter simulation device outputs a three-phase voltage at a normal frequency. v PMG Undervoltage fault simulation switch S LV Overvoltage fault simulation switches S at all levels OV1 S OV2 …S OVn All phases are disconnected, and the main motor simulation device outputs normal three-phase voltage. v M ; Step 4: Conduct over-frequency, over-over-frequency, under-frequency, and under-frequency protection function tests using a permanent magnet auxiliary exciter simulation device. Step 5: Conduct undervoltage and overvoltage protection function tests using a main motor simulation device.

6. The design method of the static simulation device for testing the protection function of the voltage regulator as described in claim 5, characterized in that: The design of the permanent magnet auxiliary exciter simulation device in step 4 includes the following steps: Step 401, close S LLF S LF S OF or S OOF This causes the permanent magnet auxiliary exciter simulation device to output three-phase voltages that are over-frequency, under-frequency, or under-frequency. v PMG ; Step 402: Switch the normal frequency output of the permanent magnet auxiliary exciter simulation device to the abnormal frequency, and at the same time increase the voltage amplitude output of inverter A. Step 403: Set the switching frequency of SVPWM to 20 times the highest output frequency of inverter A, and design the cutoff frequency of filter A to be twice the highest output frequency of inverter A. Use filter A to filter out the high-frequency components in SVPWM and leave the fundamental frequency components.

7. The design method of the static simulation device for testing the protection function of the voltage regulator as described in claim 5, characterized in that: The design of the main motor simulation device in step 5 includes the following steps: Step 501, close S LV This causes the main motor simulation device to output an undervoltage three-phase voltage. v M ; Step 502, when S OV1 S OV2 …S OVn When any one of them is closed, the main motor simulation device outputs an effective value of [value]. V p1 , V p2 … V pn Three-phase voltage v M and maintain overvoltage respectively t p1 , t p2 … t pn After the voltage was restored to normal V Maintain overvoltage t p1 , t p2 … t pn Set to the corresponding protection time t 1. t 2… t n 1.3 times; Step 503: Set the switching frequency of SVPWM to 25 times the highest output frequency of inverter B, and design the cutoff frequency of filter A to 3 times the highest output frequency of inverter A. Use filter B to filter out the high-frequency components in SVPWM and leave the fundamental frequency components.

8. The design method of the static simulation device for testing the protection function of the voltage regulator as described in claim 5, characterized in that: In step 5, when the main motor outputs an abnormal voltage simulation, open-loop control is used to ensure rapid voltage regulation.

9. The design method of the static simulation device for testing the protection function of the voltage regulator as described in claim 5, characterized in that: When the main motor outputs a normal voltage, closed-loop voltage control is used to ensure the accuracy of the output voltage.

10. The design method of the static simulation device for testing the protection function of the voltage regulator as described in claim 8, characterized in that: The abnormal voltage simulation includes undervoltage simulation and overvoltage simulation.

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