WO2018006517A1 - Method for detecting instantaneous current in intermediate dc link of ac-dc-ac circuit and locomotive - Google Patents

Method for detecting instantaneous current in intermediate dc link of ac-dc-ac circuit and locomotive Download PDF

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WO2018006517A1
WO2018006517A1 PCT/CN2016/104652 CN2016104652W WO2018006517A1 WO 2018006517 A1 WO2018006517 A1 WO 2018006517A1 CN 2016104652 W CN2016104652 W CN 2016104652W WO 2018006517 A1 WO2018006517 A1 WO 2018006517A1
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current
phase
link
circuit
absolute values
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PCT/CN2016/104652
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French (fr)
Chinese (zh)
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肖桦
贾峰
蔡志伟
杨曦亮
刘忠伟
李昭宇
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中车大连机车车辆有限公司
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Publication of WO2018006517A1 publication Critical patent/WO2018006517A1/en
Priority to ZA2018/04022A priority Critical patent/ZA201804022B/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
    • H02M5/40—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc

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  • the invention relates to an instantaneous current detecting method for an intermediate DC link of a cross-connecting circuit and a locomotive, and belongs to the technical field of locomotives.
  • the AC-DC transmission locomotive needs to use the instantaneous current signal of the intermediate DC link for the closed-loop control of the locomotive traction and auxiliary system. Therefore, the real-time and accuracy of the instantaneous current detection of the intermediate DC link is very important.
  • the most common solution is to use a current shunt, that is, the resistance of the shunt is fixed.
  • a current shunt When a DC current passes, a voltage is generated across the shunt, and the voltage value is measured, and then converted into a current according to Ohm's law. value. Due to the small resistance of the shunt, heat loss occurs during operation, especially when measuring large currents.
  • the shunt since the shunt is connected in series in the circuit when used, the measured signal and the sampling signal cannot be isolated, which poses a safety hazard.
  • Another solution of the prior art is to use a Hall-type current sensor.
  • the signal collected by this scheme is easily interfered by the capacitor discharge in the intermediate DC link. If the signal is filtered, there will be a delay phenomenon and the real-time performance is poor.
  • the object of the present invention is to overcome the above deficiencies of the prior art, and to provide an instantaneous current detecting method for an intermediate DC link of a cross-connecting circuit and a locomotive.
  • the object of the present invention is achieved as follows: an instantaneous current detecting method for an intermediate DC link of an AC-DC circuit, the current transformer synchronously collecting three-phase A, B, and C phase current signals Ia, Ib, and Ic of the input side of the bridge rectifier, and the characteristics thereof Continuation of the following steps:
  • phase current signals Ia, Ib, Ic are sent to the microcomputer controller
  • the microcomputer controller takes the absolute values of the phase current signals Ia, Ib, and Ic, respectively, and obtains the absolute values of the phase currents Ia1, Ib1. Ic1;
  • phase current absolute values Ia1, Ib1, Ic1 are summed to obtain a total current value I1;
  • An AC-DC transmission locomotive is characterized in that the above-mentioned intermediate DC link instantaneous current detection method is adopted.
  • the solution of the invention only needs to detect the three-phase current of the AC input side, and the instantaneous current value of the intermediate DC link can be obtained, which is suitable for three-phase input waveforms of sinusoidal, rectangular, sawtooth, pulse, etc., and the measured signal and the three
  • the AC current and DC current of the phase bridge rectifier circuit are completely isolated, and the signal can be detected safely and effectively.
  • the circuit is simple, low in cost, accurate and real-time.
  • FIG. 1 is a schematic view showing the principle of a main circuit of an AC-DC transmission locomotive according to an embodiment of the present invention.
  • FIG. 2 is a flow chart of a method for detecting an instantaneous current of an intermediate DC link of an AC-DC circuit according to an embodiment of the present invention.
  • FIG. 1 is a schematic diagram of the principle of the main circuit of the AC/DC power transmission locomotive according to the embodiment of the present invention.
  • the three-phase AC power generated by the main generator G of the diesel locomotive is supplied to the DC bus through the bridge rectifier, and there are two capacitors between the bridge rectifier and the inverter. .
  • a number of auxiliary systems and a number of traction motors M receive power from the DC busbars via respective inverters.
  • the three-phase A, B, and C phase current signals Ia, Ib, and Ic of the bridge rectifier input side are synchronously collected by a current transformer (not shown) and then supplied to the microcomputer controller.
  • FIG. 2 a flow chart of a method for detecting an instantaneous current of an intermediate DC link of an AC-DC circuit according to an embodiment of the present invention is shown.
  • Proceed to block 2.1 to start detection; enter box 2.2 to synchronously collect three-phase current signals Ia, Ib, and Ic; enter block 2.3 to perform absolute value calculation on current signal I a to obtain current absolute value Ia1; enter block 2.4 to calculate absolute value of current signal Ib Calculate to obtain the current absolute value Ib1; enter the block 2.5 to calculate the absolute value of the current signal Ic to obtain the current absolute value Ic1; enter the frame 2.6 to sum Ia1, Ib1, Ic1 to obtain the total current value I1; enter the box 2.7 to calculate three The phase bridge rectified output instantaneous current value Iz I1/2, and then proceeds to block 2.8 to return to the main routine.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Electric Propulsion And Braking For Vehicles (AREA)

Abstract

A method for detecting an instantaneous current in an intermediate DC link of an AC-DC-AC circuit and a locomotive. The method comprises: a current transformer synchronously collecting phase current signals Ia, Ib and Ic of three phases A, B and C at an input side of a bridge rectifier (2.2); conveying same to a micro-computer controller, and the micro-computer controller respectively calculating absolute values of the phase current signals Ia, Ib and Ic to obtain phase current absolute values Ia1, Ib1 and Ic1 (2.3, 2.4, 2.5); then, performing summation on the phase current absolute values Ia1, Ib1 and Ic1 to obtain a total current value I1 (2.6); and finally, calculating an instantaneous current value Iz ＝ I1/2 in an intermediate DC link (2.7). As long as three phase currents at an AC input side are detected, an instantaneous current value in an intermediate DC link can be obtained, which is applicable to a three-phase input waveform of types such as sine, rectangle, sawtooth and pulse types. A detected signal is completely isolated from an alternating current and a direct current of a three-phase-bridge rectification circuit. A signal can be detected securely and effectively, and the circuit is simple and low in cost, and has high accuracy and a good real-time performance.

Description

交直交电路中间直流环节瞬时电流检测方法及机车Instantaneous current detection method for intermediate DC link of AC/DC circuit and locomotive 技术领域Technical field
本发明涉及一种交直交电路中间直流环节瞬时电流检测方法及机车,属于机车技术领域。The invention relates to an instantaneous current detecting method for an intermediate DC link of a cross-connecting circuit and a locomotive, and belongs to the technical field of locomotives.
背景技术Background technique
交直交电传动机车需要将中间直流环节的瞬时电流信号用于机车牵引及辅助系统的闭环控制，因此对中间直流环节的瞬时电流检测的实时性和准确性非常重要。The AC-DC transmission locomotive needs to use the instantaneous current signal of the intermediate DC link for the closed-loop control of the locomotive traction and auxiliary system. Therefore, the real-time and accuracy of the instantaneous current detection of the intermediate DC link is very important.
在现有技术中，最常见的方案是采用电流分流器，即分流器的阻值固定，直流电流通过时在分流器两端产生电压，测得这个电压值，然后根据欧姆定律将其换算成电流值。由于分流器的阻值较小，工作时会产生损耗发热，尤其在测量大电流时发热功率更大。另外由于分流器在使用时串联在电路中，被测信号和取样信号不能隔离，存在安全隐患。In the prior art, the most common solution is to use a current shunt, that is, the resistance of the shunt is fixed. When a DC current passes, a voltage is generated across the shunt, and the voltage value is measured, and then converted into a current according to Ohm's law. value. Due to the small resistance of the shunt, heat loss occurs during operation, especially when measuring large currents. In addition, since the shunt is connected in series in the circuit when used, the measured signal and the sampling signal cannot be isolated, which poses a safety hazard.
现有技术的另一种方案是采用霍尔式电流传感器。这种方案采集到的信号容易受到中间直流环节中电容放电的干扰，若对信号进行滤波处理则会有延时现象，实时性较差。Another solution of the prior art is to use a Hall-type current sensor. The signal collected by this scheme is easily interfered by the capacitor discharge in the intermediate DC link. If the signal is filtered, there will be a delay phenomenon and the real-time performance is poor.
申请号为201120562073.1的中国专利申请《一种三相整流桥输出直流电流无源隔离取样电路》，将三相交流电流经过进线电流互感器和电流转换电阻将大电流转换为低幅值的交流信号电压，三相交流信号电压采用Y型接法，经信号整流桥输出电路转换为直流电压。该直流信号电压与直流电流按一定的取样比例关系完全对应，通过并联的直流电压表对应显示直流电流幅值，信号整流桥输出并联电容滤波。虽然该方案隔离性强，减少了损耗，但是电路组成复杂、成本较高。Application No. 201120562073.1 Chinese patent application "a three-phase rectifier bridge output DC current passive isolation sampling circuit", the three-phase alternating current through the line current transformer and current conversion resistor to convert large current into low amplitude AC The signal voltage and the three-phase AC signal voltage are connected to the DC voltage through the Y-connected method of the signal rectifier bridge output circuit. The DC signal voltage and the DC current are completely corresponding according to a certain sampling ratio relationship, and the DC current meter correspondingly displays the DC current amplitude, and the signal rectifier bridge output parallel capacitor filter. Although the scheme is highly isolated and reduces losses, the circuit composition is complicated and the cost is high.
发明内容Summary of the invention
本发明的目的就是克服上述现有技术之不足，提供一种交直交电路中间直流环节瞬时电流检测方法及机车。The object of the present invention is to overcome the above deficiencies of the prior art, and to provide an instantaneous current detecting method for an intermediate DC link of a cross-connecting circuit and a locomotive.
本发明的目的是这样实现的：一种交直交电路中间直流环节瞬时电流检测方法，电流互感器同步采集桥式整流器输入侧三相A、B、C相电流信号Ia、Ib、Ic，其特征在于继续下列步骤：The object of the present invention is achieved as follows: an instantaneous current detecting method for an intermediate DC link of an AC-DC circuit, the current transformer synchronously collecting three-phase A, B, and C phase current signals Ia, Ib, and Ic of the input side of the bridge rectifier, and the characteristics thereof Continuation of the following steps:
E.将相电流信号Ia、Ib、Ic输送给微机控制器；E. The phase current signals Ia, Ib, Ic are sent to the microcomputer controller;
F.微机控制器对相电流信号Ia、Ib、Ic分别取绝对值，得到相电流绝对值Ia1、Ib1、 Ic1；F. The microcomputer controller takes the absolute values of the phase current signals Ia, Ib, and Ic, respectively, and obtains the absolute values of the phase currents Ia1, Ib1. Ic1;
G.对相电流绝对值Ia1、Ib1、Ic1求和，得到总电流值I1；G. The phase current absolute values Ia1, Ib1, Ic1 are summed to obtain a total current value I1;
H.计算中间直流环节瞬时电流值Iz＝I1/2。H. Calculate the instantaneous current value Iz=I1/2 of the intermediate DC link.
一种交直交电传动机车，其特征在于采用上述中间直流环节瞬时电流检测方法。An AC-DC transmission locomotive is characterized in that the above-mentioned intermediate DC link instantaneous current detection method is adopted.
本发明的方案，只需检测交流输入侧三相电流，即可得出中间直流环节的瞬时电流值，适用于正弦、矩形、锯齿、脉冲等类型的三相输入波形，将被测信号与三相桥式整流电路的交流电流、直流电流完全隔离，可安全、有效地检测到信号，电路简单、成本低、准确性和实时性好。The solution of the invention only needs to detect the three-phase current of the AC input side, and the instantaneous current value of the intermediate DC link can be obtained, which is suitable for three-phase input waveforms of sinusoidal, rectangular, sawtooth, pulse, etc., and the measured signal and the three The AC current and DC current of the phase bridge rectifier circuit are completely isolated, and the signal can be detected safely and effectively. The circuit is simple, low in cost, accurate and real-time.
附图说明DRAWINGS
图1为本发明实施例的交直交电传动机车主电路原理示意图。1 is a schematic view showing the principle of a main circuit of an AC-DC transmission locomotive according to an embodiment of the present invention.
图2为本发明实施例的交直交电路中间直流环节瞬时电流检测方法程序流程图。2 is a flow chart of a method for detecting an instantaneous current of an intermediate DC link of an AC-DC circuit according to an embodiment of the present invention.
具体实施方式detailed description
为使本发明实施例的目的、技术方案和优点更加清楚，下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。The technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.
参看图1本发明实施例的交直交电传动机车主电路原理示意图，内燃机车主发电机G发出的三相交流电通过桥式整流器向直流母排供电，桥式整流器和逆变器间有两个电容。若干辅助系统和若干牵引电机M通过各自的逆变器从直流母排取电。通过电流互感器(图中未示出)同步采集桥式整流器输入侧三相A、B、C相电流信号Ia、Ib、Ic，然后将其输送给微机控制器。1 is a schematic diagram of the principle of the main circuit of the AC/DC power transmission locomotive according to the embodiment of the present invention. The three-phase AC power generated by the main generator G of the diesel locomotive is supplied to the DC bus through the bridge rectifier, and there are two capacitors between the bridge rectifier and the inverter. . A number of auxiliary systems and a number of traction motors M receive power from the DC busbars via respective inverters. The three-phase A, B, and C phase current signals Ia, Ib, and Ic of the bridge rectifier input side are synchronously collected by a current transformer (not shown) and then supplied to the microcomputer controller.
参看图2本发明实施例的交直交电路中间直流环节瞬时电流检测方法程序流程图。进入框2.1开始检测；进入框2.2同步采集三相电流信号Ia、Ib、Ic；进入框2.3对电流信号Ia进行绝对值运算，得到电流绝对值Ia1；进入框2.4对电流信号Ib进行绝对值运算，得到电流绝对值Ib1；进入框2.5对电流信号Ic进行绝对值运算，得到电流绝对值Ic1；进入框2.6对Ia1、Ib1、Ic1进行求和，得到总电流值I1；进入框2.7计算三相桥式整流输出瞬时电流值Iz＝I1/2，然后进入框2.8返回主程序。Referring to FIG. 2, a flow chart of a method for detecting an instantaneous current of an intermediate DC link of an AC-DC circuit according to an embodiment of the present invention is shown. Proceed to block 2.1 to start detection; enter box 2.2 to synchronously collect three-phase current signals Ia, Ib, and Ic; enter block 2.3 to perform absolute value calculation on current signal I a to obtain current absolute value Ia1; enter block 2.4 to calculate absolute value of current signal Ib Calculate to obtain the current absolute value Ib1; enter the block 2.5 to calculate the absolute value of the current signal Ic to obtain the current absolute value Ic1; enter the frame 2.6 to sum Ia1, Ib1, Ic1 to obtain the total current value I1; enter the box 2.7 to calculate three The phase bridge rectified output instantaneous current value Iz = I1/2, and then proceeds to block 2.8 to return to the main routine.
最后应说明的是：以上实施例仅用以说明本发明的技术方案，而非对其限制；尽管参照前述实施例对本发明进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分技术特征进行等同替换；而 这些修改或者替换，并不使相应技术方案的本质脱离本发明各实施例技术方案的精神和范围。 It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not limited thereto; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that Modifications to the technical solutions described in the foregoing embodiments, or equivalent replacement of some of the technical features; These modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (2)

  1. 一种交直交电路中间直流环节瞬时电流检测方法，电流互感器同步采集桥式整流器输入侧三相A、B、C相电流信号Ia、Ib、Ic，其特征在于继续下列步骤：An instantaneous DC current detection method for an intermediate DC link of an AC-DC circuit, the current transformer synchronously acquires three-phase A, B, and C phase current signals Ia, Ib, and Ic of the input side of the bridge rectifier, and is characterized by continuing the following steps:
    A.将相电流信号Ia、Ib、Ic输送给微机控制器；A. The phase current signals Ia, Ib, Ic are sent to the microcomputer controller;
    B.微机控制器对相电流信号Ia、Ib、Ic分别取绝对值，得到相电流绝对值Ia1、Ib1、Ic1；B. The microcomputer controller takes the absolute values of the phase current signals Ia, Ib, Ic, respectively, to obtain the absolute values of the phase currents Ia1, Ib1, Ic1;
    C.对相电流绝对值Ia1、Ib1、Ic1求和，得到总电流值I1；C. The phase current absolute values Ia1, Ib1, Ic1 are summed to obtain a total current value I1;
    D.计算中间直流环节瞬时电流值Iz＝I1/2。D. Calculate the instantaneous current value Iz=I1/2 of the intermediate DC link.
  2. 一种交直交电传动机车，其特征在于采用权利要求1所述中间直流环节瞬时电流检测方法。 An AC-DC transmission locomotive characterized by using the intermediate DC link instantaneous current detecting method of claim 1.
PCT/CN2016/104652 2016-07-07 2016-11-04 Method for detecting instantaneous current in intermediate dc link of ac-dc-ac circuit and locomotive WO2018006517A1 (en)

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