Device and method for measuring initial electrical parameters of special linear motor

Abstract

The invention discloses a device and method for measuring initial electrical parameters of a special linear motor, and belongs to the field of pulse power technology and application, and the method comprises the steps: connecting two identical pulse power modules with the special linear motor through a cable, switching on a thyristor in the first pulse power module at the moment t = 0, and switching on a thyristor in the second pulse power module at the moment t = t0; a thyristor in the second pulse power module is switched on, the capacitor voltage # imgabs0 # and the output current # imgabs1 # in the first pulse power module at the t0 moment are measured, a first voltage jump value # imgabs2 # is obtained according to the bore tail voltage waveform, the initial inductance value L0 of the special linear motor system is obtained, a second voltage jump value # imgabs3 # is obtained according to the bore tail voltage waveform, and the initial inductance value L0 of the special linear motor system is obtained; obtaining an initial resistance value R0 of the special linear motor system; according to the method, the initial electrical parameters (the initial inductance and the initial resistance) under the actual working condition can be obtained by utilizing the circuit changing rule, the real electrical parameters under the pulse large current condition are accurately reflected, and the method has important significance for improving the accuracy of a system full-circuit simulation model.

Description

Technical Field

[0001] The invention belongs to the field of pulse power technology and application, and specifically relates to a device and method for measuring initial electrical parameters of a special linear motor. Background Art

[0002] The special linear motor is composed of a single-turn or multi-turn guide rail. The armature, as the launch object of the special linear motor, is located between the two guide rails / main rails. When the pulse power supply feeds a large pulse current to the special linear motor, the transient strong magnetic field generated by the guide rail interacts with the current flowing through the armature, generating a Lorentz force that pushes the armature to accelerate in the bore. The equivalent circuit model of the special linear motor system is a resistive-inductive load. When the armature is at the starting position in the bore, its equivalent initial electrical parameters in the circuit are the initial resistance and initial inductance. The actual size of the initial electrical parameters reflects the electrical performance of the armature at the starting position in the entire discharge circuit, laying the foundation for the armature optimization design and the prediction of the system's full circuit simulation performance.

[0003] The existing measurement methods for the initial electrical parameters of special linear motor systems are mainly the microohmmeter method and the RLC tester method. The microohmmeter method applies a constant current to both ends of the bore and uses Ohm's law to calculate its resistance value. The resistance value measured is the steady-state resistance value obtained under a small signal constant current source, and it takes a certain amount of time to stabilize the current and measure the voltage drop. The time for stabilizing the current is often longer than the duration of the pulsed large current. The RLC tester method applies an AC voltage or current signal of known frequency and amplitude to the bore through an internal signal source, and uses an LCR bridge to calculate its impedance value. The impedance value measured is the multiple sampling and average value obtained under a small signal AC source.

[0004] The pulsed high current that drives the special linear motor system is generated by the pulse power module according to a predetermined sequence. It contains DC and harmonic components of various frequencies. Its current peak value is hundreds of kiloamperes to megaamperes, and its duration is milliseconds. In the existing measurement methods, the measurement value obtained by the microohmmeter method only corresponds to the DC component of the initial electrical parameters under the small signal source, and the measurement value obtained by the RLC tester method only corresponds to the harmonic component of a certain frequency under the small signal source. From the measurement principle, both of these measurement methods have limitations and cannot reflect the true value of the initial electrical parameters under transient extreme conditions. Therefore, it is necessary to establish a measurement method for the initial electrical parameters. The measurement environment provided in the new method should be consistent with the actual working conditions, and should include the DC component of the initial electrical parameters and the harmonic components of various frequencies, reflecting the transient characteristics under the pulsed high current, such as the influence of the skin effect, etc., which can truly reflect the electrical performance of the armature at the starting position and ensure the accuracy of the full circuit simulation performance prediction. Summary of the invention

[0005] In view of this, on one hand, the present invention provides a device for measuring the initial electrical parameters of a special linear motor, wherein the measuring device comprises a first pulse power module and a second pulse power module, the two pulse power modules are connected to the special linear motor through a cable, the first pulse power module and the second pulse power module are connected in parallel, and the two pulse power modules have the same topological structure. In each pulse power module, the anode of the thyristor is connected to the positive electrode of the capacitor, the cathode of the thyristor is connected to the cathode of the diode, one end of the reactor is connected to the cathode of the thyristor, and the other end of the reactor serves as the positive electrode of the pulse power module, the negative electrode of the capacitor is connected to the anode of the diode and also serves as the negative electrode of the pulse power module; the components in the two pulse power modules have the same electrical parameters.

[0006] Another aspect of the present invention provides a method for measuring initial electrical parameters of a special linear motor, comprising the following steps:

[0007] Step 1, connecting two identical pulse power modules to a special linear motor via a cable, wherein the armature in the special linear motor is located at a starting position of movement in the bore;

[0008] Step 2, at time t=0, turning on the thyristor in the first pulse power module;

[0009] Step 3, at t=t 0 At this moment, the thyristor in the second pulse power module is turned on, and t 0 The capacitor voltage in the first pulse power module at the moment With output current , where t 0 The time should be before the freewheeling diode in the first pulse power module is turned on, and t 0 At this moment, the armature does not move in the chamber (usually t 0 The selected value is less than 100μs);

[0010] Step 4: Obtain the first voltage jump value according to the voltage waveform at the end of the bore , get the initial inductance value L of the special linear motor system 0 : , where L L is the inductance of the reactor, L cable is the cable inductance, U C is the charging voltage value of the capacitor;

[0011] Step 5: Obtain a second voltage jump value according to the tail voltage waveform , get the initial resistance value R of the special linear motor system 0 :

[0012] ,

[0013] Among them, L Z = L cable + L 0 , that is, L Z Including cable inductance L cable The initial inductance value L of the special linear motor system 0 , R S = R C + R SCR + R L , that is, R S Including capacitor resistance R C , thyristor resistance R SCR , Reactor resistance R L .

[0014] The present invention has the following beneficial effects:

[0015] The present invention adopts a pulse power supply to drive a special linear motor. There is no need to add an additional power supply. The voltage jump value caused by the conduction moment of the thyristors of the two pulse power modules is used to obtain the initial electrical parameters of the special linear motor system under actual working conditions using the switching rule, which accurately reflects the real electrical parameters under pulsed large current conditions, and is of great significance to improving the accuracy of the full circuit simulation model of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0017] Figure 1 A circuit diagram of a device for measuring initial electrical parameters of a special linear motor provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other. To achieve the above-mentioned purpose, the present invention adopts the following technical scheme.

[0019] It should be noted that the terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0020] See also Figure 1 , an embodiment of the present invention provides a circuit diagram of a device for measuring initial electrical parameters of a special linear motor. Figure 1 As shown, the first pulse power module is connected in parallel with the second pulse power module, and the two pulse power modules have the same topological structure. The anode of the thyristor is connected to the positive electrode of the capacitor, the cathode of the thyristor is connected to the cathode of the diode, one end of the reactor is connected to the cathode of the thyristor, and the other end of the reactor serves as the positive electrode of the pulse power module. The negative electrode of the capacitor is connected to the anode of the diode and serves as the negative electrode of the pulse power module at the same time. The components in the two pulse power modules have the same electrical parameters, and the electrical parameters corresponding to the capacitor are the capacitor resistance value R C , the charging voltage value of the capacitor U C , the electrical parameter corresponding to the thyristor is the thyristor resistance value R SCR The electrical parameter corresponding to the reactor is the inductance value L of the reactor. L , Reactor resistance R L The electrical parameter corresponding to the cable is the cable inductance value L cable , Cable resistance value R cable The two ends of the capacitor in the first pulse power module are connected to the first voltage measuring instrument V 1 , the first current measuring instrument A is connected between the positive electrode of the first pulse power module current and the reactor 1 The positive poles of the two pulse power modules are connected to the cable, the cable is connected to the tail of the special linear motor system, and the two ends of the tail of the special linear motor system are connected to the first voltage measuring instrument V b ; Among them, the armature is located at the starting position of movement in the bore.

[0021] The embodiment of the present invention provides a method for measuring the initial electrical parameters of a special linear motor, comprising the following steps:

[0022] Step 1, connecting two identical pulse power modules to a special linear motor via a cable, wherein the armature in the special linear motor is located at a starting position of movement in the bore;

[0023] Step 2, at time t=0, turning on the thyristor in the first pulse power module;

[0024] Step 3, at t=t 0 At this moment, the thyristor in the second pulse power module is turned on, and t 0 The capacitor voltage in the first pulse power module at the moment With output current , where t 0 The time should be before the freewheeling diode in the first pulse power module is turned on, and t 0 At this moment, the armature does not move in the chamber (usually t 0 The selected value is less than 100μs);

[0025] Step 4: Obtain the first voltage jump value according to the voltage waveform at the end of the bore , get the initial inductance value L of the special linear motor system 0 : , where L L is the inductance of the reactor, L cable is the cable inductance, U C is the charging voltage value of the capacitor;

[0026] Step 5: Obtain a second voltage jump value according to the tail voltage waveform , get the initial resistance value R of the special linear motor system 0 :

[0027] ,

[0028] Among them, L Z = L cable + L 0 , that is, L Z Including cable inductance L cable The initial inductance value L of the special linear motor system 0 , R S = R C + R SCR + R L , that is, R S Including capacitor resistance R C , thyristor resistance R SCR , Reactor resistance R L .

Claims

1. A device for measuring the initial electrical parameters of a special linear motor, characterized in that: The measuring device includes a first pulse power module and a second pulse power module, the two pulse power modules are connected to the special linear motor through a cable, the first pulse power module and the second pulse power module are connected in parallel, the two pulse power modules have the same topological structure, in each pulse power module, the anode of the thyristor is connected to the positive electrode of the capacitor, the cathode of the thyristor is connected to the cathode of the diode, one end of the reactor is connected to the cathode of the thyristor, the other end of the reactor serves as the positive electrode of the pulse power module, the negative electrode of the capacitor is connected to the anode of the diode and also serves as the negative electrode of the pulse power module; the components in the two pulse power modules have the same electrical parameters.

2. The device according to claim 1, characterized in that The electrical parameter corresponding to the capacitor is the capacitor resistance value R C , the charging voltage value of the capacitor U C , the electrical parameter corresponding to the thyristor is the thyristor resistance value R SCR The electrical parameter corresponding to the reactor is the inductance value L of the reactor. L , Reactor resistance R L The electrical parameter corresponding to the cable is the cable inductance value L cable , Cable resistance value R cable .

3. The device according to claim 1, characterized in that The two ends of the capacitor in the first pulse power module are connected to the first voltage measuring instrument V1, and the positive electrode of the current of the first pulse power module and the reactor are connected to the first current measuring instrument A1.

4. The device according to claim 1, characterized in that The positive poles of the two pulse power modules are connected to the cable, the cable is connected to the tail of the special linear motor system, and the two ends of the tail of the special linear motor system are connected to the first voltage measuring instrument V b ; Among them, the armature is located at the starting position of movement in the bore.

5. A method for measuring the initial electrical parameters of a special linear motor according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1, connecting two identical pulse power modules to a special linear motor via a cable, wherein the armature in the special linear motor is located at a starting position of movement in the bore; Step 2, at time t=0, turning on the thyristor in the first pulse power module; Step 3: At t=t0, turn on the thyristor in the second pulse power module and measure the capacitor voltage in the first pulse power module at t0. With output current , where t0 should be before the moment when the freewheeling diode in the first pulse power module is turned on, and the armature does not move in the bore at t0, and the value selected for t0 is less than 100μs; Step 4: Obtain the first voltage jump value according to the tail voltage waveform , and obtain the initial inductance value L0 of the special linear motor system: ， Among them, L L is the inductance of the reactor, L cable is the cable inductance, U C is the charging voltage value of the capacitor; Step 5: Obtain a second voltage jump value according to the voltage waveform at the end of the bore , and get the initial resistance value R0 of the special linear motor system: ， Among them, L Z = L cable + L0, i.e. L Z Including cable inductance L cable The initial inductance value L0, R of the special linear motor system S = R C + R SCR + R L , that is, R S Including capacitor resistance R C , thyristor resistance R SCR , Reactor resistance R L .

Images