CN114325267B

CN114325267B - Enhancement mode new energy automobile motor interturn testing arrangement

Info

Publication number: CN114325267B
Application number: CN202111639784.9A
Authority: CN
Inventors: 范宇; 石文文; 黄成涛; 白洪超
Original assignee: Qingdao Ainuo Instrument Co ltd
Current assignee: Qingdao Ainuo Instrument Co ltd
Priority date: 2021-12-29
Filing date: 2021-12-29
Publication date: 2022-08-30
Anticipated expiration: 2041-12-29
Also published as: CN114325267A

Abstract

The invention relates to an enhanced new energy automobile motor turn-to-turn testing device.A turn-to-turn high-voltage oscillating circuit comprises a silicon controlled rectifier, a diode, a resistance-capacitance voltage division module and a filtering module which are connected in series and is used for generating high voltage, storing turn-to-turn impact energy and forming a turn-to-turn impact discharge conduction loop; each silicon controlled rectifier is connected with a silicon controlled rectifier control circuit in parallel, and the silicon controlled rectifier control circuit is used for controlling the conduction of the silicon controlled rectifier series circuit, and continuously giving a conduction signal and protecting voltage difference caused by series connection in the oscillation process; the signal processing and waveform sampling circuit is connected to a resistance-capacitance voltage division module and a filtering module of the turn-to-turn high-voltage oscillation circuit and used for carrying out high-speed sampling and waveform data storage and calculation. The invention improves the turn-to-turn oscillation period and amplitude, and makes the change of the oscillation waveform more obvious.

Description

Enhancement mode new energy automobile motor interturn testing arrangement

Technical Field

The invention belongs to the technical field of new energy automobile testing, and particularly relates to an enhanced new energy automobile motor turn-to-turn testing device.

Background

The driving motor of the new energy automobile generally outputs periodic voltage containing higher harmonics through a controller to drive and regulate the speed, and a winding of the driving motor bears continuous high-frequency pulse voltage during operation. Once the motor winding has the bad hidden danger of turn-to-turn insulation, compare the three-phase asynchronous motor winding that bears the power frequency voltage, turn-to-turn short circuit trouble appears more easily in new energy automobile driving motor, leads to the motor to damage or arouse unpredictable consequences such as spontaneous combustion. Therefore, the requirement on the reliability of turn-to-turn insulation of the motor is high.

Compared with an alternating current asynchronous motor used in a common industrial occasion, the new energy automobile driving motor has the special requirements of high endurance mileage, low speed, high torque control and the like, has the characteristics of large working current and low copper consumption (copper consumption refers to energy loss consumed on a motor winding, the winding generally adopts a copper wire, the energy loss is generally referred to as copper consumption and copper loss in the industry for short), and the winding resistance is controlled at the level of dozens of milliohms. Therefore, the cross section area of the electromagnetic wire is larger, so that the number of turns in the slot is smaller, the inductance of the winding is also lower, and the turn-to-turn waveform oscillation period is shorter. In addition, the structural strength requirement of the driving motor is high, the iron core is thick, and the aluminum shell with the water cooling channel is directly arranged outside the driving motor, so that the iron loss (iron loss refers to the energy loss consumed on the iron core of the motor, such as hysteresis loss and eddy current loss, and the energy loss is generally referred to as 'iron loss' and 'iron loss' in the industry) is high during turn-to-turn testing, the attenuation speed of the turn-to-turn waveform is high, and the attenuation speed is usually completed in two or three cycles.

Therefore, when the driving motor of the new energy automobile has slight turn-to-turn defects, the waveform difference is not obvious because the period and the area of the oscillating waveform of the driving motor are small, the waveform period is short, the attenuation speed is high, the waveform sampling data in the effective oscillation time are small, and the difference of the calculated quantized data is also small. In the actual turn-to-turn test, even slight turn-to-turn sparking occurs, but the quantized data are not out of tolerance and are judged to be qualified.

The interturn insulation impact test is an effective method for detecting the interturn insulation failure and the winding parameter change before the motor leaves the factory. During testing, a (or a group of) high-voltage pulse with extremely short wave front time is output, and an LC oscillation circuit formed by an oscillation capacitor in the testing module and a winding of a tested motor forms an oscillation attenuation waveform, wherein the attenuation speed of the oscillation attenuation waveform is influenced by the factors of circuit impedance and iron core loss. Because a plurality of groups of pulses output during turn-to-turn testing have the characteristics of high voltage and high frequency (the wave front time is less than or equal to 0.5us), the windings with the hidden danger of poor turn-to-turn insulation can form breakdown at the insulation weak point. Once breakdown is caused by poor turn-to-turn insulation, the number of turns of the winding is changed, the winding parameters are changed, and the frequency or the amplitude of the turn-to-turn oscillation waveform is changed. At the moment, the measured motor oscillating waveform is compared with the standard motor oscillating waveform, and the waveform difference is calculated into quantitative parameters such as area, area difference and the like, so that whether the measured motor winding has a turn-to-turn poor fault or not can be judged.

As shown in fig. 1, a charging module mostly generates a direct-current high voltage by using a half-wave rectification or voltage-doubling rectification mode to charge an energy storage capacitor C3. When the energy storage capacitor C3 is detected to be charged to the voltage with set parameters, a plurality of series-connected Silicon Controlled Rectifiers (SCR) are Controlled to be conducted, and the voltage of the energy storage capacitor C3 is instantly applied to a parallel circuit of the oscillation capacitor C4 and the winding of the motor to be detected. When the energy storage capacitor C3 discharges, the voltage thereof gradually drops, and the current flows to the winding to be tested through the controllable silicon. When the forward current approaches 0, the oscillation voltage approaches a negative peak value, reverse current starts to be generated, the controllable silicon is turned off under the action of the reverse current, the energy storage capacitor C3 is separated from the oscillation loop under the isolation action of the high-voltage diode D2 and the controllable silicon, and the LC oscillation process is changed to be carried out between the winding to be tested and the oscillation capacitor C4. Because direct current resistance exists in the oscillation loop and the measured winding and iron loss exists in the iron core of the measured winding, energy is continuously consumed in the oscillation process, oscillation is continuously attenuated until the energy is exhausted, and oscillation is finished.

The high-voltage and oscillating circuit has the following defects:

1. the conventional turn-to-turn test oscillation circuit mostly adopts a special oscillation capacitor C4 for LC oscillation, and in order to enable the turn-to-turn oscillation waveform amplitude of a driving motor of a new energy automobile to be higher, the period to be longer and the period number to be more, so that the oscillation waveform can have more obvious difference change when slight ignition occurs, the parameter of the oscillation capacitor C4 needs to be improved. Although the mode of increasing the oscillation capacitor C4 is equivalent to increasing the value of C in LC oscillation, the cycle time of the oscillation wave can be increased to a certain extent, and the number of oscillation cycles is increased, but the oscillation capacitor C4 and the energy storage capacitor C3 in the circuit have a certain voltage division ratio relationship, so that the parameter of the oscillation capacitor C4 is greatly increased, the inter-turn output voltage is reduced, and the voltage reduction can cause that the inter-turn insulation breakage point cannot be broken down, thereby bringing about the problem of the detection output power reduction.

2. The sampling frequency of the existing turn-to-turn test waveform is generally 40MHz, the sampling frequency is 0.204ms for collecting 8 kbytes under the highest sampling frequency, and the turn-to-turn effective oscillation time of a part of new energy automobile motors is 0.1ms or even shorter, so that the problem of insufficient sampling data of the turn-to-turn waveform with shorter oscillation time of the new energy automobile motors is caused, and certain influences are brought to waveform difference calculation and corona waveform characteristic identification. When the combination turns are slightly poor, the difference of the oscillation waves is small, and the judgment of the product as qualified is easy to be mistaken when slight ignition occurs.

Disclosure of Invention

In order to solve the technical problems, the invention provides an enhanced new energy automobile motor turn-to-turn testing device, which solves the problems of small slight sparking waveform difference caused by low turn-to-turn waveform amplitude and short period of a motor, small number of waveform points caused by too fast attenuation and low sampling frequency, insufficient waveform difference quantization calculation discrimination and inaccurate corona waveform acquisition in the testing process of the conventional turn-to-turn testing equipment. The technical scheme adopted by the invention is as follows:

an enhancement mode new energy automobile motor interturn testing arrangement includes: the device comprises a device shell, wherein a turn-to-turn high-voltage oscillation circuit, a silicon controlled control circuit and a signal processing and waveform sampling circuit are arranged in the device shell; the turn-to-turn high-voltage oscillation circuit comprises a plurality of thyristors, diodes, a resistance-capacitance voltage division module and a filtering module which are connected in series, is used for generating high voltage, storing turn-to-turn impact energy and forming a turn-to-turn impact discharge conduction loop, is used for forming an LC oscillation loop with a tested motor winding during turn-to-turn testing, and is used for establishing a forward and reverse current channel and protecting a thyristor control circuit during oscillation; each silicon controlled rectifier is connected with a silicon controlled rectifier control circuit in parallel, and the silicon controlled rectifier control circuit is used for controlling the conduction of the silicon controlled rectifier series circuit, and continuously giving a conduction signal and protecting voltage difference caused by series connection in the oscillation process; the signal processing and waveform sampling circuit is connected to a resistance-capacitance voltage division module and a filtering module of the turn-to-turn high-voltage oscillation circuit and is used for carrying out high-speed sampling and waveform data storage and calculation processing on the divided waveform signals.

The invention has the beneficial effects that:

1. on the premise of not reducing impulse voltage and not losing impulse energy, the invention can improve the turn-to-turn oscillation period and amplitude, thereby enabling the change of the oscillation waveform to be more obvious when slight turn-to-turn failure occurs.

2. Aiming at the characteristics of short turn-to-turn oscillation period and high attenuation speed of a motor of the new energy automobile, the invention can improve the turn-to-turn sampling frequency, acquire more wave points in a shorter oscillation period, ensure that the turn-to-turn undesirable characteristic points such as slight deviation of the waveform, corona burrs and the like can be restored into the sampled waveform, and further be quantized into a test parameter for judgment through calculation.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are specific embodiments of the invention, and that other drawings within the scope of the present application can be obtained by those skilled in the art without inventive effort.

FIG. 1 is a schematic diagram of a high voltage and oscillation circuit of a conventional turn-to-turn testing apparatus;

FIG. 2 is a schematic diagram of an inter-turn high voltage oscillating circuit of a test apparatus according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a thyristor control circuit of the test apparatus of an embodiment of the invention;

FIG. 4 is a schematic diagram of a signal processing and waveform sampling control circuit of a test apparatus according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a comparison between test oscillation waveforms of a conventional test apparatus and the test apparatus of the present invention.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention.

An enhancement mode new energy automobile motor interturn testing arrangement includes: the device comprises a device shell, wherein a turn-to-turn high-voltage oscillation circuit, a silicon controlled control circuit and a signal processing and waveform sampling circuit are arranged in the device shell.

The turn-to-turn high-voltage oscillation circuit comprises a plurality of thyristors, a resistance-capacitance voltage division module and a filtering module which are connected in series and used for generating high voltage, storing turn-to-turn impact energy and forming a turn-to-turn impact discharge conduction loop, wherein the turn-to-turn impact discharge conduction loop is used for forming an LC oscillation loop with a tested motor winding during turn-to-turn test, and is used for establishing a forward and reverse current channel and protecting a thyristor control circuit during oscillation.

Fig. 2 is a schematic diagram of an inter-turn high-voltage oscillation circuit of a testing apparatus according to an embodiment of the present invention, which includes six groups of thyristors. The turn-to-turn high-voltage oscillation circuit includes: the back end of the turn-to-turn charging module is connected to an energy storage capacitor C3, the energy storage capacitor C3 is connected with a measured motor winding through a silicon controlled rectifier series circuit in a turn-to-turn high-voltage oscillation circuit, each silicon controlled rectifier is connected with an independent silicon controlled rectifier control circuit in the silicon controlled rectifier series circuit, voltage-sharing protection circuits (R1-R6 and VR 1-VR 6) and reverse current circuits (D1-D6) are sequentially connected in parallel on the silicon controlled rectifier series circuit (SCR 1-6), and the tail end of the turn-to-turn high-voltage oscillation circuit is connected with a signal processing and waveform sampling circuit and the measured motor winding through a resistance-capacitance voltage division module (R8 and R9) and a filter module (C5).

The interturn charging module is used for charging the energy storage capacitor C3 to a set voltage, and the energy storage capacitor C3 is used for storing impact energy. Unlike the conventional inter-turn detection capacitor which is specially provided with the C4 oscillation capacitor, the energy storage capacitor C3 in the inter-turn high-voltage oscillation circuit of the invention participates in inter-turn oscillation in the test process and is used as the oscillation capacitor. The controllable silicon series circuit (SCR 1-6) is used for controlling impact energy output and constructing a forward current channel in the oscillation process, the voltage-sharing protection circuit (R1-R6 and VR 1-VR 6) is used for voltage average distribution and protection of the series controllable silicon in the controllable silicon series circuit, and the reverse current circuit (D1-D6) is used for constructing a reverse current channel in the oscillation process.

The operating principle of the turn-to-turn high-voltage oscillating circuit is as follows: c3 is an energy storage capacitor, and after the capacitor is charged by the turn-to-turn charging module at the previous stage, the voltage of the capacitor reaches the set voltage required by the test. Secondly, the system discharge control is formed by connecting silicon controlled rectifiers 1-6 in series, and each silicon controlled rectifier parallel resistor R1-R6 and the piezoresistor VR are subjected to voltage sharing and protection, so that the system can bear voltage in proportion. The number of the series-connected thyristors is determined according to voltage parameters of specific models, and the invention adopts 6 thyristors to be connected in series and can be reliably used for 5kv voltage output. Comparing with the traditional turn-to-turn test oscillation circuit (shown in fig. 1), the invention (shown in fig. 2) does not have the high-voltage diode D2 and the oscillation capacitor C4 in fig. 1 at the rear stage of the thyristor. And fourthly, the silicon controlled rectifier is reversely connected with diodes D1-D6 in parallel, and the diodes are reversely biased and are not conducted in the charging stage of the energy storage capacitor. After the thyristor is turned on, the energy storage capacitor C3 begins to discharge, and a forward current path is formed through the thyristor. When the forward current tends to 0, the oscillation waveform voltage reaches a negative peak value, at the moment, the controllable silicon is closed under the action of reverse current, the reverse current flows back to the energy storage capacitor C3 through the diodes D1-D6 which are connected in series, and the LC oscillation process is continued. The thyristor control circuit needs to give a continuous conducting signal, when the first oscillation reverse current approaches to 0, the voltage waveform reaches a second positive peak value, and the forward current can not pass through the series loop of the diodes D1-D6. Because the series controlled silicon loop bears the action of forward voltage, under the condition that the controlled silicon continuously gives a control signal, the forward current makes the controlled silicon conducted again, the forward current flows to the coil of the tested motor through the controlled silicon series loop in the second oscillation period, and the LC oscillation process is continued. And sixthly, reciprocating in such a way, the oscillating forward current flows from the energy storage capacitor (equivalent to an oscillating capacitor at the moment) C3 to the measured winding L through the silicon controlled loop under the control of the continuous conduction signal of the silicon controlled, the oscillating reverse current flows from the measured winding L to the energy storage capacitor (equivalent to an oscillating capacitor at the moment) C3 through the loops of the series diodes D1-D6 until the energy attenuation is finished, and the oscillation process is finished.

Each thyristor is connected with a thyristor control circuit in parallel, and the thyristor control circuit is used for controlling the conduction of the thyristor series circuit, continuously giving a conduction signal in the oscillation process and protecting voltage difference caused by series connection. The circuit has 6 groups, and each group is respectively connected with and controls the conduction of the corresponding controllable silicon in the turn-to-turn high-voltage oscillation circuit.

Fig. 3 is a schematic diagram of a thyristor control circuit of the testing apparatus according to the embodiment of the invention. The silicon controlled rectifier control circuit includes: high speed gate driver ucc27517, digital isolator iso7740 and DC/DC power isolation circuitry. The number of the controllable silicon control circuits is 6, each group of the controllable silicon control circuits is independently connected with and controls one controllable silicon, the 6 groups of the controllable silicon control circuits share a conduction control signal given by an FPGA through a digital isolator, and each group of the DC/DC power isolation circuits are connected to the same digital power supply. In the silicon controlled rectifier control circuit, a high-speed gate driver ucc27517 is used for driving a silicon controlled rectifier to be opened, a digital isolator iso7740 is used for isolating a high-speed gate driver input signal from a conduction control signal given by an FPGA, and a DC/DC power isolation circuit is used for isolating a digital power supply system from a silicon controlled rectifier control circuit power supply.

The operating principle of the silicon controlled control circuit is as follows: after the turn-to-turn test is started, when the MCU detects that the charging module is charged, the FPGA is informed to send out a door opening signal, the FPGA sends out a conduction signal to 6 groups of silicon controlled rectifier control circuits, the control signal is sent to a grid driver through a digital isolator, and the grid driver controls the conduction of the corresponding silicon controlled rectifiers. Secondly, in the testing process, the FPGA continuously gives a control signal, and each group of control circuits continuously controls the conduction of the SCR, so that the silicon controlled rectifiers 1-6 can be timely started and conducted under the action of forward current in the oscillation process; and thirdly, because the thyristors 1 to 6 are connected in series in the oscillating circuit, the voltage of the energy storage capacitor C3 is averagely borne by the voltage-sharing resistor, so that the voltages of all the thyristors 1 to 6 to the ground are different, and voltage difference exists between the thyristors. Therefore, each path of silicon controlled drive circuit needs to be designed with special voltage isolation, and voltage difference existing between each path of silicon controlled drive circuit after voltage division is prevented from being broken down and damaging devices.

The signal processing and waveform sampling circuit is connected to the resistance-capacitance voltage division modules (R8, R9) and the filtering module (C5) of the turn-to-turn high-voltage oscillation circuit. The signal processing and waveform sampling circuit is used for dividing and filtering the waveform of the measured oscillation, and after the waveform signal after voltage division enters the waveform processing and sampling control circuit, high-speed sampling and waveform data storage and calculation processing are carried out.

FIG. 4 is a schematic diagram of a signal processing and waveform sampling control circuit of a test apparatus according to an embodiment of the present invention. The signal processing and waveform sampling control circuit includes: the system comprises an inter-turn waveform signal processing circuit, an AD converter, an FPGA and an MCU which are sequentially connected, wherein the inter-turn waveform signal processing circuit is composed of an operational amplifier, and the inter-turn waveform signal processing circuit is between voltage division and sampling control. The turn-to-turn waveform signal processing circuit is used for adjusting the divided turn-to-turn waveform signals to be suitable for the sampling range of the AD converter, the input end of the turn-to-turn waveform signal processing circuit is connected with the voltage dividing circuit of the turn-to-turn high-voltage oscillation circuit, the output end of the turn-to-turn waveform signal processing circuit is connected with the AD converter, the FPGA is designed into a double-path parallel data interaction port, one end of the FPGA is connected with the AD converter, and the other end of the FPGA is connected with the MCU. The FPGA is connected with the AD converter through a CLK signal. In the waveform sampling circuit, an AD converter is used for converting turn-to-turn waveform signals into digital quantity, an FPGA is used for controlling enabling of the AD converter, control of sampling frequency CLK of the AD converter and storage of waveform data, and an MCU is used for sending a discharge control instruction to the FPGA, is connected with the FPGA through a parallel port, writes in the sampling frequency, reads waveform data cached by the FPGA, and performs processing calculation.

The working principle of the signal processing and waveform sampling control circuit is as follows: after the interturn oscillation waveform passes through a voltage division module (R8, R9) and a filter module (C5) circuit, waveform signals enter a signal processing and waveform sampling control circuit, wherein a waveform sampling part is designed into an MCU + FPGA framework, MCU writes sampling frequency setting parameters into FPGA during testing, after MCU detects that a charging module is charged, the FPGA is informed to send a conduction signal to a silicon controlled rectifier control circuit, the FPGA simultaneously enables an AD converter, and sends a CLK frequency signal up to 200MHz to the AD converter according to the setting sampling frequency parameters, at the moment, the AD converter carries out analog-digital conversion according to the frequency of the CLK signal, the FPGA reads converted interturn waveform data through a parallel bus between the FPGA and the AD converter, and the waveform data is cached in an 8 kbyte depth RAM arranged in the FPGA. And after the FPGA finishes sampling, the MCU is informed to read the cached waveform data through the parallel buses between the FPGA and the MCU, and the MCU performs waveform difference comparison calculation and corona characteristic extraction. The circuit design can still ensure that 8k byte original waveform points are used for program analysis and calculation for turn-to-turn oscillation waveforms with the shortest oscillation period of 41us, and can meet the requirement of sampling data of the turn-to-turn waveforms of the motor of the new energy automobile.

Fig. 5 is a schematic diagram showing a comparison between the test oscillation waveforms of the conventional test equipment and the test apparatus of the present invention, where the upper part is the waveform measured by the conventional test equipment, and the lower part is the waveform measured by the test apparatus of the present invention. The invention connects the energy storage capacitor in series to the test loop in the inter-turn oscillation stage through the specially designed oscillation circuit. According to the design, an energy storage capacitor with a relatively large capacitance value is used as an oscillation capacitor, the waveform at the lower part in the figure 5 is the inter-turn test oscillation waveform of the device, and compared with the oscillation waveform of the conventional inter-turn test equipment, when the device disclosed by the invention is used for carrying out inter-turn test on a motor of a new energy automobile, the single period of the waveform is longer, the peak value of each period is higher, the integral attenuation speed of the oscillation waveform is slower, and the oscillation duration is longer. Therefore, when the device of the invention tests the tested motor with poor inter-turn performance, the inter-turn waveform of the poor motor generates more obvious deviation compared with the inter-turn waveform of the normal motor, and the poor product is easier to judge; and the conventional inter-turn equipment is easy to generate misjudgment because the waveform of the poor inter-turn motor is not greatly different from the waveform of the normal motor. Because the invention has no oscillation capacitor, the problem of output voltage drop caused by simply increasing the oscillation capacitor can be avoided, and the impact energy can hardly be reduced due to the oscillation capacitor; in order to achieve the inter-turn oscillation effect of the present invention, the conventional device needs to increase the oscillation capacitor, and the input voltage thereof will drop significantly due to the voltage division of the oscillation capacitor, which may cause a problem of reduced inter-turn detection power. In addition, by increasing the sampling frequency, the invention can acquire more voltage points for restoring the oscillation waveform in a shorter time, and can ensure that software is more accurate in calculating waveform difference and waveform corona characteristics. In conclusion, theoretical analysis calculation and experimental verification show that the method can enhance the turn-to-turn oscillation amplitude and period and delay the waveform attenuation speed on the premise of not losing the output voltage, so that the change degree of the waveform when the turn-to-turn insulation is poor is increased. By improving the sampling speed, enough sampling points can be obtained for calculating the oscillating waveform when the rapidly decaying oscillating waveform is tested, and the test effect is obviously improved for samples with low impedance, short turn-to-turn oscillation period and rapid decay of the high-iron-loss motor of the new energy automobile.

Furthermore, the inter-turn charging module can be realized by adopting various modes such as half-wave rectification, voltage-doubling rectification, high-voltage pack and the like. The FPGA in the waveform sampling control circuit can be realized by a CPLD or other programmable logic devices, and the AD converter in the waveform sampling control circuit can also be realized by other brands or higher-frequency AD converters.

Finally, it is to be noted that: the above examples are only specific embodiments of the present invention, and are not intended to limit the technical solutions of the present invention, and the scope of the present invention is not limited thereto. Those skilled in the art will understand that: any person skilled in the art can modify or easily conceive the technical solutions described in the foregoing embodiments or equivalent substitutes for some technical features within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included therein.

Claims

1. The utility model provides an enhancement mode new energy automobile motor interturn testing arrangement which characterized in that includes: the device comprises a device shell, wherein a turn-to-turn high-voltage oscillation circuit, a silicon controlled control circuit and a signal processing and waveform sampling circuit are arranged in the device shell; the turn-to-turn high-voltage oscillation circuit comprises a plurality of thyristors, diodes, a resistance-capacitance voltage division module and a filtering module which are connected in series, is used for generating high voltage, storing turn-to-turn impact energy and forming a turn-to-turn impact discharge conduction loop, is used for forming an LC oscillation loop with a tested motor winding during turn-to-turn testing, and is used for establishing a forward and reverse current channel and protecting a thyristor control circuit during oscillation; each silicon controlled rectifier is connected with a silicon controlled rectifier control circuit in parallel, and the silicon controlled rectifier control circuit is used for controlling the conduction of the silicon controlled rectifier series circuit, and continuously giving a conduction signal and protecting voltage difference caused by series connection in the oscillation process; the signal processing and waveform sampling circuit is connected to a resistance-capacitance voltage division module and a filtering module of the turn-to-turn high-voltage oscillation circuit and is used for carrying out high-speed sampling and waveform data storage and calculation processing on the divided waveform signals;

the turn-to-turn high-voltage oscillation circuit includes: the back end of the turn-to-turn charging module is connected to an energy storage capacitor C3, the energy storage capacitor C3 is connected with a tested motor winding through a silicon controlled rectifier series circuit in a turn-to-turn high-voltage oscillation circuit, each silicon controlled rectifier is connected with an independent silicon controlled rectifier control circuit in the silicon controlled rectifier series circuit, a voltage-sharing protection circuit and a reverse current circuit are sequentially connected in parallel on the silicon controlled rectifier series circuit, and the tail end of the turn-to-turn high-voltage oscillation circuit is connected with a signal processing and waveform sampling circuit and the tested motor winding through a resistance-capacitance voltage division module and a filtering module.

2. The enhanced new energy automobile motor turn-to-turn testing device according to claim 1, wherein the thyristor control circuit comprises: the high-speed grid driver is used for driving the silicon controlled rectifier to be opened, the digital isolator is used for isolating input signals of the high-speed grid driver and conducting control signals given by the FPGA, and the DC/DC power supply isolation circuit is used for isolating a digital power supply system and a power supply of the silicon controlled rectifier control circuit.

3. The enhanced new energy automobile motor turn-to-turn testing device according to claim 1, wherein the signal processing and waveform sampling circuit comprises: the system comprises an inter-turn waveform signal processing circuit, an AD converter, an FPGA and an MCU which are sequentially connected, wherein the inter-turn waveform signal processing circuit is composed of an operational amplifier and is used for adjusting a divided inter-turn waveform signal to be suitable for the sampling range of the AD converter, the input end of the inter-turn waveform signal processing circuit is connected with a voltage dividing circuit of a inter-turn high-voltage oscillation circuit, and the output end of the inter-turn waveform signal processing circuit is connected with the AD converter.

4. The enhanced new energy automobile motor turn-to-turn testing device as claimed in claim 3, wherein the FPGA is designed as a two-way parallel data interaction port, one end of the FPGA is connected with the AD converter, the other end of the FPGA is connected with the MCU, and the FPGA is simultaneously connected with the AD converter through a CLK signal.

5. The enhanced new energy automobile motor turn-to-turn testing device according to claim 1, wherein the turn-to-turn charging module adopts a half-wave rectification, a voltage-doubling rectification or a high-voltage packet mode, and the FPGA in the waveform sampling control circuit adopts a CPLD or other programmable logic devices.