一、（1）设备概述
“NAZJX变压器变比整检装置”（简称“变检”）是用来检定0.1级及以下变压器变比测试仪的变比精度和分辨率的一种装置，同时可以检定变比组别测试仪在组别测试时的变比精度和各种组别选择的正确性，并包括Z形组别。
（2）原理结构
仪器中A、B、C分别为三相输入，接变比测试仪的一次侧，a、b、c为三相输出，接变比测试仪的二次侧。功能开关是功能选择开关，可选择四种功能的测量。选择开关在组别选择时使用，该开关具有三相PT的不同组别的选择功能，同时还可选择Z形组别。X、Y、Z、x、y、z、a，、b，、c，、x，、y，、z，是在检定本装置的标准变比PT和标准三相PT的准确度时使用，除此之外，没有其他用途，但相互不能短接。
二、使用方法
使用时A、B、C、a、b、c与变比组别测试仪的相应端子连接，A、B、C为一次输入电压端钮，a、b、c为二次输出电压端钮。功能选择开关具有4种功能选择，当它置于某一功能档时，“变检”就只能对变比组别测试仪的这一功能进行测试。
K1、K2为组别选择开关，K2、K3为Z形组别选择开关，根据面板上给出的“组别开关选择表”有关K1、K2、K3中的数值来确定此时所选择的组别状态。
分辨率选择开关有两种，即小数点后两位数和三位数的选择。当作分辨率测试时，所显示的小数部分应是标准值与倍率的乘积，两部分小数可以相互迭加，而整数部分始终显示25。
三、性能指标
1. 变比测试功能
可预置的标准变比值是：220/110、220/35、220/10、220/6、110/35、110/10、110/6、35/10、35/6、35/0.4、10/10、10/6、10/0.4、6/0.4、27.5/0.4、27.5/6、24/6、110、550、1100（共20个）即：UAB/Uab的值有上述20种选择，此时，UAB的额定电压为400V，该装置可在额定电压的20%～120%内工作，二次电压Uab可以承担大于等于100KΩ的负荷，即要求被试变比测试仪的二次输入阻抗≥100KΩ，此时的标准变比值的误差小于0.02%。
2. 分辨率测试功能
当功能选择开关置于“分辨率”时，可测试变比测试仪所显示值的分辨率，“变检”可预置25.001、25.002、……25.099共99个值，供测试各种变比测试仪的分辨率时使用，在分辨率测试时，对误差不作要求，但检定变比测试仪分辨率时，变比测试仪的显示值应该随分辨率的增减有明显的变化。
3. 组别测试功能
“变检”将标准三相PT按一次星形、二次星形或三角形和一次三角形、二次星形或三角形接法组成12种组别，可对变比组别测试仪的全部组别进行测试，同时在组别测试时的变比值可有25（10/0.4）、87.5（35/0.4）、1050三种选择，其组别测试时的标准三相PT的各单相误差全部小于0.1%。
4. Z形组别测试功能
Z形组别共有10组（△/Z或Y/Z），其它性能指标与上述的“组别测试功能”完全相同。
5．直通测试功能
该功能是将变比测试仪的一次电压UAB直接连接于二次端（a、b端）即UAB=Uab，可对变比测试仪进行1/1的自校，注意不能在不允许直通的变比测试仪的检定中使用。

NAZJX transformer variable ratio of entire inspection device
Variable ratio checking device, transformer testing device, variable ratio testing device, variable ratio checking device
Overview of NAZJX
"NAZJX transformer ratio of the entire inspection device" (referred to as "variable") is used to test 0.1 and below transformer ratio tester than the accuracy and resolution of a device, and can test variable ratio group tester In the group test when the variable ratio accuracy and the accuracy of various groups of choice, and includes Z-shaped group.
First, the principle of structure
Instrument A, B, C, respectively, for three-phase input, junction ratio of the primary side of the tester, a, b, c for the three-phase output, connected to the secondary side of the tester. Function switch is a function selector switch, you can select the four functions of the measurement. The selector switch is used for group selection. This switch has a selection function for different groups of three-phase PTs, and a Z-shaped group can be selected. X, Y, Z, x, y, z, a ,, b ,, c ,, x ,, y ,, z, is used in verifying the accuracy of the standard transformation PT and the standard three- In addition, there is no other purpose, but not short of each other.
Second, use range of this tester
When used, A, B, C, a, b, c and variable ratio group tester connected to the corresponding terminal, A, B, C for the input voltage side button, a, b, c for the secondary output voltage side button. Function selector switch has four kinds of function selection, when it is placed in a function file, the "variable inspection" can only change the ratio of the group tester to test this function.
K1 and K2 are the group selection switches, and K2 and K3 are the Z group selection switches. The groups selected at this time are determined by the values in K1, K2 and K3 according to the "group switch selection table" given on the panel Do not state.
There are two resolution selection switches, that is, after the decimal point of two digits and three digits of choice. As a resolution test, the fractional part of the display should be the product of the standard value and the magnification, the two parts can be superimposed on each other, and the integer part always shows 25.
Third, performance indicators
1. Variable ratio test function
The presettable ratio values are:
220/6, 220/10, 220/6, 110/35, 110/10, 110/6, 35/10, 35/6,35/4, 10/10, 10/6, UAB / Uab value of the above-mentioned 20 kinds of options, this time, UAB rated voltage of 400V (1), UAB / , The device can work in the rated voltage of 20% to 120%, the secondary voltage Uab can bear 100KΩ or more load, which requires the test variable ratio tester secondary input impedance ≥ 100KΩ, then the standard variable ratio Of the error is less than 0.02%.
2. Resolution test function
When the function selector switch is set to "Resolution", it can test the resolution of the value displayed by the ratio tester, and the "check" can preset 25.001, 25.002, ... 25.099, 99 values for testing various variable ratio When the resolution of the tester is used, the error is not required in the resolution test, but when the test is changed to the resolution of the tester, the display value of the ratio tester should change obviously with the increase or decrease of the resolution.
3. Group test function
"PT" will be the standard three-phase PT by a star, the second star or triangle and a triangle, the second star or delta connection composed of 12 groups, variable ratio group tester can be all groups , And the test values of the standard three-phase PTs are 25 (10 / 0.4), 87.5 (35 / 0.4), 1050 respectively. The single-phase errors of the standard three-phase PTs are all less than 0.1%.
4.Z-shaped group test function
There are 10 groups (△ / Z or Y / Z) in the Z-shaped group. The other performance indexes are the same as the above "group test function".
5. Through test function
This function is to connect the primary voltage UAB of the ratio tester directly to the secondary end (a, b terminal), that is UAB = Uab, can carry on the 1/1 self-calibration of the variable ratio tester, pay attention not to Variable ratio test instrument used in the test.