GB/T 2900.15-1997 Electrical terminology transformers, mutual inductors, voltage regulators and reactors
Some standard content:
GB/T2900.15—1997
The terms listed in this standard comprehensively cover the main varieties, technical performance, structural features, tests and usage functions of current transformer products to meet the needs of production, ordering, scientific and technological exchanges, publishing and foreign trade. This standard adopts IEC:50(421):1990 International Electrotechnical Vocabulary Part 421 Transformers and Reactors and TFC.50(321):1986 International Electrotechnical Vocabulary Part 321 Transformers. In addition to including all the terms in IEC50(421) and IEC50(321) (the content of these terms is equivalent to that of 1EC standards), this standard also includes IEEEstd100 "Electrical Engineering Terms" and some terms that are of great value to this profession that appear in other IEC and IEEE standards. It also compiles some terms that are currently in urgent need with reference to famous domestic and foreign literature. This standard is a revision of GB2900.15-82 (Electrical terminology transformer, mutual inductor, voltage regulator and reactor). When revising GB2900.15-82, more than 40 terms that are outdated, inappropriate or inappropriate to be included were deleted, and several terms with improper original explanations or names were rewritten; some test methods for reflecting product characteristics, new product and new component terms, etc., a total of 118 terms were added. This standard replaces the original GB2900.15-82 standard from the date of implementation. This standard is issued by the Ministry of Machinery of the People's Republic of China The Ministry of Industry proposed that this standard be managed by the National Technical Committee for Standardization of Transformers. The main drafting unit of this standard is Shenyang Transformer Research Institute. The main drafters of this standard are Zhang Yi and Tian Wenge. This standard is interpreted by Shenyang Transformer Research Institute. This standard was first issued in February 1982.
This standard was first revised in March 1997. 1 Scope
National Standard of the People's Republic of China
Electrical Terms
Transformers, Mutual Inductors, Voltage Regulators and ReactorsElectrotechnical terminology Transformer, instrument transformer, voltage regulator and reactor This standard specifies the terminology of transformer, mutual inductor, voltage regulator and reactor. GB/T 2900.15: 1997
neq IEC 50(421):1990
IEC50(321):1986
代栋 GB 2900.1582
This standard is applicable to the formulation of standards, the compilation of technical documents, the writing and translation of professional manuals, teaching materials and books and periodicals, 2 General terms
2.1 General terms for transformers and reactors
2.1.1 Rated value
The numerical value of a set of parameters marked on transformer products to indicate the operating characteristics of the product under specified conditions. The numerical values of these parameters are the basis for the manufacturer's guarantee and testing. 2.1.2 Rated parameters rated quantities The operating characteristics of the transformer are expressed by the numerical values of the rated parameters. It includes the rated capacity, rated voltage, rated current, rated drop and rated temperature rise, etc.
2.1.3 Rated capacity ratedpnwer
The conventional value of the apparent power marked on the winding and the rated voltage of the winding determine the rated current value. Note
1 The two groups of a double-winding transformer have the same rated capacity, so by definition, it is the rated capacity of the transformer. 2 For multi-winding transformers, the rated capacity of each group should be given. 3 For reactor products, except for reactors for certain purposes (such as shunt reactors), the rated capacity is generally not marked, only the rated current is marked. 2.1.4 Rated voltage (of a winding) rated voltagc (of a winding) Between the line terminals of a three-phase transformer or a three-phase reactor, or between the terminals of a single-phase transformer or a single-phase reactor. A specified voltage is induced when applied or no-loaded. 2.1.5 Rated voltage ratio (of a transformer) ratedt voltageratio (of a 2.1.6 Rated frequency The frequency of the AC power supply based on which transformer products are designed. 2.1.7 Rated current (on a transformer or shunt reactor) The current flowing through the line terminals of the winding, which is equal to the rated capacity of the winding divided by the rated voltage of the winding and the corresponding phase factor (for single-phase, the phase factor is 1, and for three-phase, it is /3).
Approved by the State Technical Supervision Department on July 3, 1997 and implemented on May 1, 1998
GB/T 2900.151997
2.1.8 Rated continuous current Rated continuous current For current-limiting reactors, it refers to the continuous current value based on which they are designed. h) For grounding transformers (neutral point couplers), it refers to the continuous current flowing through the neutral point at rated voltage and rated frequency based on which it is designed.
2.1.9 Rated short-time current Rated short-time current For current-limiting reactors or neutral-grounding reactors, it refers to the fault current value designed to withstand for a specified time. b) For grounding transformers (neutral point couplers), it refers to the neutral point current value designed to withstand for a specified time. 2.1.10 Rated current of arc suppression reactor When the main winding of arc suppression reactor is connected to the maximum current tap and the rated voltage is applied at the rated frequency, the current value that can be withstood for a specified time.
2.1.11 Tapping (tap)
Tap drawn from the coil to change the voltage ratio. 2.1.12 Prinuipaltapping The tapping corresponding to the rated parameters,
2.1.13 Tapping factor tapping factor refers to the ratio U./UN (tapping factor) or 100Ua/U% (tapping factor percentage), where: U - rated voltage of the winding:
When a pair of untapped windings is applied with rated voltage, the voltage induced between the ends of the windings at the specified tapping position when no load.
Note: The tapping factor indicates the "effective voltage" of the tapped winding at the corresponding tapping position. When it is equal to 1, it means that the winding is in the main tapping.
4 Plus tapping
Tapping with a tapping factor greater than 1.
2.1.15 Minus tapping
Tapping with a tapping factor less than 1.
2.1.16 Tapping step
The difference in percentage between two adjacent taps 2.1.17 Tapping range
The range of variation of the tapping factor compared to 100 Note: The range of variation of the tapping factor is from 100+ to 100. This tapping range is -α%, -6%. When a=b, it is -a%. 2.1.18 Tapping voltage ratio (of a pair of windings) When the tapped winding is a high voltage winding, its tapping voltage ratio is equal to the rated voltage ratio multiplied by the tapping factor of the winding. When the tapped winding is a low voltage winding, its tapping voltage ratio is equal to the rated voltage ratio divided by the tapping factor of the winding. 2.1.19 Tapping duty
The value marked on some parameters (such as voltage, current) is used for the specified tapping connection position, which serves as the guarantee basis of the manufacturer and, in some cases, as the basis for testing. 2.1.20 Tapping quantities The value of the tapping parameter is used to characterize the tapping condition. For each winding and each tap, the tapping parameters should include: a) tapping voltage;
b) tapping capacity; bzxZ.net
c) tapping current.
Note: The tapping parameters refer to the specified tapping of the transformer, which is applicable to any winding, including windings without tapping. 2.1.21 Tapping voltage of a winding GB/T 2900.15—1997
For a specified tapping, the voltage applied or induced at no load is specified between the line terminals of a three-phase transformer winding or between the winding terminals of a single-phase transformer. 2.1.22 Tapping Power of a winding The customary value of apparent power at a specified tapping, used as the basis for manufacturer's guarantee and, in some cases, as the basis for testing.
2.1.23 Tapping current of a winding The current flowing through the line terminals of a winding, which is equal to the tapping capacity of the winding divided by the tapping voltage of the winding and the corresponding phase factor (for single-phase, the phase factor is 1; for three-phase, it is /3). 2.1.24 Full-power tapping The tapping capacity is equal to the rated capacity. 2.7.25 Recluced-power tapping The tapping capacity is less than the rated capacity. 2.1.26 Connection group symbol cnnner:tion symbol A general symbol that uses a group of letters and clock numbers to indicate the connection method of the high voltage, medium voltage (if any) and low voltage windings of a transformer and the relative phase displacement of the medium and low voltage windings to the high voltage winding. 2.1.27 Phase displacement (transformer) phasedisplacemcnt (for a transformer) When the positive sequence voltage system is applied to the high voltage terminals marked in alphabetical or numerical order, the angular difference between the voltage phasor between the neutral point (real or imaginary) and the line terminal of the low voltage (medium voltage) winding and the voltage phasor between the neutral point and the corresponding line terminal of the high voltage winding. The phasors are assumed to rotate counterclockwise. 2.1.2B Corresponding terminals Terminals of different windings of the transformer marked with the same letters or symbols. 2.1.29 Connection diagran of windings A schematic diagram showing the electrical connections and relative positional relationships between the windings of the transformer or between the taps of a winding. 2.1.30 Total losses
The sum of no-load losses and load losses.
1. For multi-winding transformers, total losses refer to the load combination at the specified locations. 2. The losses in auxiliary equipment are not included in the total losses and should be listed separately. 2.1.31 Load losses
a) Two-winding transformer (for main tap): When the tapped winding is connected to its main tap position, when the rated current flows through the line terminals of one winding and the other winding is short-circuited, the active power absorbed by the transformer at rated frequency. h) Multi-winding transformer refers to a pair of windings (for main tap): When the tapped winding is connected to its main tap position, when the rated current flows through the line terminals of one of the pair of windings with a smaller rated capacity, the other winding is short-circuited until the remaining windings are open. The active power absorbed by the transformer. Notes
1 Load loss can also refer to the non-main tap. In this case, the reference current of the two-winding transformer is the tap current of the tap. For multi-winding transformers, the reference current or reference capacity is related to the specified load combination. 2 Load loss value usually refers to the effective value at the corresponding reference temperature. 2.1.32 Supplementary land Joss The loss value obtained by subtracting IR loss (converted to the corresponding reference temperature) from the load loss. Note: R is equal to direct current.
2. 1. 33 No-load loss The active power absorbed by the transformer when the rated voltage at rated frequency is applied to the terminals of one winding and the other windings are open-circuited. 2.1.34 No-load current GB/T 2900. 15-1997
The current flowing through the line terminals when the rated voltage at rated frequency is applied to the terminals of one winding and the other windings are open-circuited. Notes
1 When the excitation winding has a tap, it should be connected to the main tap. 2 The no-load current of a winding is usually expressed as a percentage of the rated current of the winding. 2.1.35 Loss ratio
The ratio of load loss to no-load loss.
2.1.36 Impedance voltage (for principal tapping) Irmpedance voltage (for principal tapping) a) Double-winding transformer:
The value of the applied voltage when one winding is short-circuited. The voltage at rated frequency is applied to the line terminals of the other winding of a three-phase transformer, or to the terminals of the other winding of a single-phase transformer, and the rated current flows therethrough. b) Multi-winding transformer: refers to a pair of windings. The value of the applied voltage when one winding in a pair of windings is short-circuited, the voltage at rated frequency is applied to the line terminals of the other winding in the pair of three-phase transformers, or to the terminals of the other winding in the pair of single-phase transformers, the remaining windings are open-circuited, and the rated current corresponding to the smaller rated capacity of the winding in the pair flows therethrough. Note: The impedance voltage of a winding or each pair of windings is the value H at the corresponding reference temperature, expressed as a percentage of the rated voltage value of the voltage-applied winding.
2.1.37 Short-circuit impedance (of a pair of windings) The equivalent series impedance ZR between the terminals of one of a pair of windings at rated frequency and reference temperature, when the terminals of the other winding of the pair are short-circuited and the remaining windings (if any) are open-circuited. For three-phase transformers, this impedance is the equivalent of the (star-connected) impedance of each phase:
For transformers with tapped windings, the short-circuit impedance is the impedance at a certain tap position. Unless otherwise specified, it is the impedance at the main tap.
Note: The short-circuit impedance may also be expressed as a fraction of the reference impedance Z of the same winding in the pair: Here 2-
2=100
U\\-Z and Zer are the voltages of the windings (rated or tapped voltages). 5 Rated capacitance.
The above formula is applicable to both three-phase transformers and single-phase transformers. The short-circuit impedance is also equal to the ratio of the actual voltage applied to the other winding at the rated current (or tapping current) when one of the windings is short-circuited to its rated voltage (or tapping voltage). 2.1.38 reactance voltage: the component of the impedance voltage perpendicular to the current vector. 2.1.39 rexiatance voltage: the component of the impedance voltage in the direction opposite to the current vector. 2.1.40 voltage drop or rise for a specified load condition voltage regulation [or a specified load condition] the calculated difference between the no-load voltage of a winding and the voltage produced at its terminals when the winding is loaded with a specified load and a specified power. At this time, the voltage applied to the other winding is equal to: the rated voltage, if the transformer is connected to the main tap (so the no-load voltage of the previous winding is its rated voltage); or the
tap voltage, if the transformer is connected to other taps. The above difference is usually expressed as a percentage of the no-load voltage of the previous winding. ; For multi-winding transformers, the voltage drop or voltage rise is not only related to the load and power factor of the winding itself, but also to the load and power factor of the other windings.
GB/T2900.15-1997
2.1.41 Zero-sequence impedance zero-sequence impedance In three-phase zigzag or zigzag connected windings, the impedance value at rated frequency expressed in ohms per phase between the line terminals and the neutral terminal. 2.1.42 Transformer efficiency efficiency of transformer output power to input power ratio, expressed as a fraction. 2.1.43 Constant flux voltage variation (CFVV): When the transformer is in different tapping positions, the tap voltage of the non-tapped winding is constant, and the tap voltage of the tapped winding is proportional to the tapping factor.
2.1.44 Variable flux voltage variation (VFVV): When the transformer is in different tapping positions, the tap voltage of the tapped winding is constant, and the tap voltage of the non-tapped winding is inversely proportional to the tapping factor.
2.1.45 Combined voltage regulation (ChVV) In transformers with a large tapping range, the voltage regulation methods include constant flux voltage regulation and variable flux voltage regulation, thus forming a mixed voltage regulation method. At this time, the constant flux voltage regulation part is suitable for some tappings with a tapping factor less than the maximum voltage tapping factor, and the variable flux voltage regulation part is suitable for some tappings with a tapping factor greater than the maximum voltage tapping factor. 2.1.46 Temperature rise || tt || The difference between the temperature of a certain part of a transformer product and the temperature of the cooling medium. Note: For air cooling under cooling medium temperature, it refers to the temperature of the surrounding air. For water cooling, it refers to the water humidity at the entrance of the cooling equipment. 2.1.47 Equipment highest voltage UhighestvolageforequipinentU The highest root mean square value (or effective value) of the same voltage. The insulation of transformer-type electrical equipment is designed according to this. 2.1.48 Rated insulation level The insulation of transformer-type electrical equipment is designed to withstand a set of test voltage values under specified conditions. Note: These test voltages are: a) Rated impulse stroke, rated short circuit withstand voltage, rated required impulse, and rated surge withstand voltage. 2.1.49 Uniform insulation of winding All the outgoing terminals of a transformer (discharger, etc.) connected to the terminals have the same insulation to the ground power frequency withstand voltage.
2.1.50 Non uniforninsulation ofawinding transformer (reactor, etc.)When the winding ends are directly or directly grounded, the insulation level of this grounded end or neutral point end is lower than that of the line end.
2. 1.51 Dielectric absorption ratioThe ratio of the insulation resistance value measured at 60s to the value measured at 15s of an insulating structure2.1.52 Dielectric dissipation factor (tans)The ratio of the active power value absorbed by an insulating structure or insulating material under the action of a sinusoidal voltage to the absolute value of the reactive power.2.1.53 Dissolved gas (in oil) analysisDissolved gas (in oil) analysisDraw a certain amount of samples from oil-immersed transformer products and use gas chromatography to measure the composition and content of the dissolved gas in the oil.
2.1.54 Partial discharge discharge occurs between electrodes but does not penetrate. This discharge can occur near the conductor or not.
2.1.55 Sound power level (Lw) sound power level It refers to the logarithm of the ratio of the sound power generated by the equipment to the reference sound power multiplied by 10, measured in decibels. GB/T 2900. 15--1997
Note: The passband L uses the A-weighted sound power level, expressed as Lwa, and the reference sound power is 1pW (1018W). 2. 1. 56 Sound pressure level (L) sound pressure level It refers to the logarithm of the ratio of the sound pressure generated by the equipment to its reference sound pressure multiplied by 20, measured in decibels. Sign: Usually A-weighted sound pressure level is used, expressed as I, and the reference pressure is 20μPa2.2 General terms for switching on and off
2.2.1 Switching current switched urtn
The current that is designed to be interrupted on each on-off contact group or transition contact group in the diverter switch or selector switch during tap change.
2.2.2 Circulating current Current is the current generated by the voltage drop between the taps and flows through the transition impedance when two adjacent taps are bridged during tap change.
2.2.3 Rated through-current is the current flowing through the tapchanger to the external circuit. This current can be transferred from one tap to another by the tapchanger under the relevant step voltage. Under the condition of meeting the relevant regulations, the tapchanger can continuously carry this current: 2.2.4 Maximum rated through-current is the maximum rated through-current required for the contact temperature rise test and the operating condition test of the tapchanger. Note: The operating condition test referred to in this term means that the tapchanger is charged with the maximum rated through-current and subjected to the specified number of operations and tap changes equivalent to the actual operation at the relevant rated step voltage, or the corresponding number of operation tests conducted under the equivalent conditions of the above test conditions. 2.2.5 Rated step voltage is the rated through-current. voltagcFor each rated through-current, the maximum permissible voltage between the two terminals of the tapchanger connected to two adjacent taps of the transformer
Note: The step voltage given for a certain rated through-current is called the "related step voltage". 2.2.6 Maximum rated step voltagemaximinum rated stepvoltaggThe maximum value of the rated step voltage designed for the tapchanger. 2.2.7 Recovery voltagetecoveryvoll.ageThe power frequency voltage appearing on the break after the breaking current is cut off for the main on-off contact group or transition contact group of the switching switch or selector switch.
2.2.8 Transition impedancetransition impedanceA resistor or reactor composed of one or more components, used to bridge the tap in use and the tap to be used, so that the load is transferred from one tap to the other without cutting off the load current or causing a significant change in the load current. At the same time, it also limits the circulating current on both taps during the period when both taps are in use. 2.2.9 Number of inberent Lapping positions The maximum number of tapping positions that a tap changer can use in half an operating cycle according to the design. 2.2.10 Number of servicc tapping positions The maximum number of tapping positions that a tap changer can use in a half operating cycle according to the design. Note: The "tap position number" used on transformers usually refers to the number of working tap positions of the tap changer. 2.2.11 Tap-change operation The entire process from start to finish by which the current is transferred from one tap of the winding to the adjacent tap. 2.2.12 Cycle of operation The action of a tap changer changing from one extreme position to another and then back to the original position. 2.2.13 Step-by-step control control An electrical and mechanical device that can stop the electric mechanism after a tap change is completed. This stop is independent of the operating sequence of the control switch.
2.3 General terms for transformers
GB/T2900.15-1997
2.3.1 Burden (of an instrument transformer) The impedance (current transformer) or admittance (voltage transformer) of the secondary circuit. Note: It should not include the impedance or admittance inside the sensor (the secondary component body). The load is often expressed in terms of apparent volt-ampere value. 2.3.2 Rated hurdlen
The load value based on which the accuracy class of the transformer is determined. 2.3.3 Accuracy class
For the error level marked on the five sensors, the ratio difference and phase difference should be within the specified limits under the specified conditions of use. 2.3.4 Primary current 2.3.5 Primary voltage The voltage applied to the secondary winding of a voltage transformer. 2.3.6 Secondary current The current flowing through the secondary winding when current flows through the primary winding of a current transformer. 2.3.7 Secondary voltage The voltage that appears between the terminals of the secondary winding when voltage is applied to the primary winding of a voltage transformer. 2.3.8 Secondary circuit The external circuit connected to the secondary winding of a voltage transformer. 2.3.9 Exciting current (of a current transformer) Exciting current (of a current transformer) The root mean square value of the current drawn by the secondary winding when a sinusoidal voltage with rated compliance is applied to the secondary terminals when the primary winding of the current transformer and other circuits are open. 2.3.1D Rated current ratio (of a current transformer) Rated transformation ratio (of a current transformer) The ratio of the rated primary current to the rated secondary current of a current transformer. 2.3.11 Rated voltage ratio (of a voltage transformer) Rated transformation ratio (of a voltage transformer) The ratio of the rated primary voltage to the rated secondary voltage of a voltage transformer. 2.3.12 Actual current ratio (of a current transformer) Actual transformation ratio (of a current transformer) The ratio of the actual secondary current in a current transformer to the actual secondary current. 2.3.13 Actual voltage ratio (of a voltage transformer) Actual transformation ratio (of a voltage transformer) The ratio of the actual primary voltage to the actual primary voltage in a voltage transformer. 2.3.14 Current error Current error The error that occurs when a current transformer measures the output current. It is caused by the actual current ratio not being equal to the rated current ratio. 2.3.15 Voltage error voltageerror
The error that occurs when a voltage transformer measures the voltage. It is caused by the actual voltage ratio not being equal to the rated voltage ratio. 2.3.16 Phase difference phasedisplacement The phase difference between the primary current (voltage) and secondary current (voltage) phases of a transformer. The direction of the phase is determined by the ideal transformer phase difference being zero.
When the secondary current (voltage) phase leads the primary current (voltage) phase, the phase difference is taken as a positive value. 2.3.17 Composite error (of a current transformer) The RMS value of the difference between the following two values in steady state when the positive signs of the primary and secondary currents coincide with those specified in the terminal markings:
a) the instantaneous value of the primary current,
b) the product of the instantaneous value of the secondary current and the rated current ratio. The composite error is usually expressed as a percentage of the RMS value of the primary current. Calculate as follows: Where: K, rated current ratio:
GB/T 2900. 15—1997
(K -ij)'de
「———Secondary current root mean square value
: -—: Secondary current instantaneous value
-——Secondary current instantaneous value;
T—period.
2.3.18 Rated short-time thermal current (of a current transformer) Rated short-time thermal current (of a current transformer) The maximum primary current root mean square that the current transformer can withstand and avoid damage within a specified time when the secondary winding is short-circuited.
2.3.19 Rated continuous thermal current (of a current transformer) Rated continuous thermal current (of a current transformer) tratislarmer) When the secondary winding is connected to the rated load, the secondary current value allowed to flow through the primary winding. At this time, the temperature rise of the current transformer does not exceed the specified limit.
2.3.20 Rated dynamic stability current ratedl dynanic current When the secondary winding is short-circuited, the current transformer can withstand the action of electromagnetic force without electrical or mechanical damage - the peak value of the secondary current.
2.3.21 Rated instrument limit - primary current (1PL) Iated inistrument limit primary current The minimum primary current value when the composite error of the measuring current transformer is equal to or greater than 10% when the secondary load is equal to the rated load.
2.3.22 Instrument security factor (FS) instrument security factor The ratio of the rated instrument limit primary current to the rated primary current. 2.3.23 Rated accuracy limit primary current (of protective current transformer) ratecd atcuracylimitprimarycurrent (afaprotecrive current 2.3.24 Error compensation The general term for various error compensation methods in transformers. The most commonly used is turns compensation. 2.3.25 Secondary limiting induced potential The product of the rated load and the impedance of the secondary winding, the instrument safety factor (or accuracy limit factor) and the rated secondary current.
2.3.26 Rated voltage factor The ratio of the maximum primary voltage that can still meet the thermal performance and accuracy requirements of the voltage transformer within the specified time to the rated primary voltage.
2.3.27 Accuracy limit factor (of a protective current transformer) The ratio of the rated accuracy limit primary current to the rated primary current. 2.3.28 Rated primary current (of a current transformer) The secondary current value used as the performance benchmark of a current transformer. 2.3.29 Rated primary voltage (of a voltage transformer) The primary voltage value used as the performance benchmark of a voltage transformer. 2.3.30 Rated secondary current (of a current transformer) The primary current value used as the performance benchmark of a current transformer. 2.3.31 Rated secondary voltage (of a voltage transformer) The secondary voltage value used as the performance benchmark of a voltage transformer. 2.3.32 Rated output (of an instrument transformer) GB/T 2900. 15—1997
The apparent power value supplied by the transformer to the secondary circuit at the rated power factor under the conditions of rated secondary current (voltage) and rated load.
2.3.33 Residual curent The sum of the instantaneous values of the three line currents in a three-phase system. 2.3.34 Extended rating curent (of a measuring current transformer)
The maximum secondary current value, expressed as a percentage of the rated primary current. At this current value, the extended current current transformer should be able to meet the temperature rise and accuracy requirements.
2.3.35 Internal burden (of a current transformer) The impedance of the secondary winding.
2.3.36 Knock point voltage kncc point voltage The voltage of the rated power applied to the secondary terminal of the current transducer. If its RMS value increases by 10%, the excitation voltage will increase by 50%. This voltage RMS value is called the knee point voltage. 2.3.37 Residual voltage residualvoluage The sum of the instantaneous values of the three phase voltages in a three-phase system. 2.3.3B High voltage terminal (capacitor voltage transducer) high voltage Lerminal (of a capacitor voltage transducer) The terminal connected to the transmission line.
2.3.39 Low voltage terminal (of a capacitor voltage transformer) low voltage terminal (of a capacitor voltage transformer) A terminal connected to ground through a carrier communication circuit or a terminal directly connected to ground. 2.3.40 Medium voltage terminal (of a capacitor voltage transformer) intermediate voltage terminal (of a capacitor voltage transformer)
A terminal connected to the electromagnetic unit in a capacitor voltage transformer. 2.3.41 Open-circuit intermediate voltage (of a capacitor voltage transformer) open-circuit intermediate voltage (of a capacitor voltage transformer)
When the primary voltage is applied between the high voltage terminal and the low voltage terminal or ground, the voltage of the medium voltage terminal of the capacitor voltage divider to ground when the electromagnetic unit is not connected to the voltage divider. 2.3.42 Voltage divider ratio of a capacitor voltage divider The ratio of the sum of the capacitance of the high voltage capacitor and the capacitance of the medium voltage capacitor to the capacitance of the high voltage capacitor. 2.3.43 Dielectric thermal stability (of current transformer) Dielectric thermal stability (nf a current transformer) is an electrical characteristic that indicates that a Shangyu current transformer with organic materials as main insulation will not have thermal breakdown during long-term operation under rated working conditions.
Note: The test conducted to determine the insulation thermal stability of the equipment is called insulation thermal stability test 2.4 Terminology for current transformers
2.4.1 Rated apparent power on line side ratedapparentpoweronlineside The apparent power of the line side winding at rated frequency, rated line side voltage and rated line side current. 2.4.2 Rated apparent power on valve side ratedapparentpoweronvalveside The apparent power of the valve side winding at rated frequency, rated valve side voltage and rated valve side current. 2.4.3 Rated cutrent on line side The AC current value of the transformer winding on the line side corresponding to the rated DC current of the converter. Note: When calculating, in multi-phase equipment, it is assumed that the current waveform of the converter circuit unit is rectangular; in single-phase equipment, the calculation basis should be stated. 2.4.4 Rated valve side current rated current on valve side The AC current value of the transformer winding on the valve side corresponding to the rated DC current of the converter. If there is a circulating current, it should be calculated. Note: When calculating, in multi-phase equipment, it is assumed that the current waveform of the converter circuit unit is rectangular; in single-phase equipment, the calculation basis should be stated; GB/T 2900.15 1997
2.4.5 Rated voltage on line side The rated voltage on line side corresponds to the transformer line voltage specified by the rated tapping. 2.4.6 Rated voltage on valve side The open-circuit voltage corresponding to the rated tap between the two phase terminals of the same-phase valve side winding that are switched successively. This value should be able to ensure the rated DC voltage of the converter under rated working conditions. 2.5 General terms for voltage regulators
2.5.1 Accuracy of a voltage stabilizing When the input voltage of an automatic voltage regulator changes within the specified range, the maximum change in the output voltage to the rated output voltage is the percentage of the rated output voltage.
2 Rated input voltage rated inputvoltage 2. 5.2
The voltage specified to be applied at the input end of the voltage regulator. 2.5.3 Input voltage range inputvoltageTanige In order to obtain the specified voltage stabilization accuracy of the output voltage of the automatic voltage regulator, the range of changes in its input voltage is allowed. 2.5.4 Rated output voltage The specified voltage value obtained at the output of the automatic voltage regulator 2.5.5 Output voltage range The range between the minimum and maximum output voltages that the voltage regulator can obtain under the rated input voltage. 2.5.6 Automatic voltage regulation speed The voltage regulation speed (expressed in V/s) required for the output voltage of the automatic voltage regulator to return from the deviation value to the rated output voltage value when the input voltage changes within the specified range and the output current changes between zero and the rated value. 2.5.7 Powerloss variation The difference between the maximum and minimum active power taken by the voltage regulator during the whole process of uniformly regulating the voltage when the output of the voltage regulator is open circuit and the rated input voltage of the rated rate is applied to the input. 2.6 General terms used for small special transformers 2.6.1 Safety extra low voltage (SEIV) safety extra low voltage Agg In a circuit isolated from the power supply by a safety isolation transformer, the simple AC voltage between conductors or between any conductor and the ground does not exceed 50V or the pulsating DC voltage does not exceed 50/2V 2.6.2 Basic insulation basic insulation Insulation on the live parts of the transformer that provides basic protection against electric shock 2.6.3
supplementary insulation independent insulation used outside the basic insulation to prevent electric shock in the event of damage to the basic insulation. 2.6.4 Double insulation double insulation insulation that has both basic insulation and supplementary insulation. 2.6.5 Reinforced insulation reinforced insulation A separate insulation structure equivalent to double insulation protection 2.7 General terms for test classification 2.7.1 Routine test routine tcst Tests conducted on each transformer product 2.7.2 Type test type test Tests conducted on one or more transformers that can represent all transformer products of the factory. 2.7.3 Special test special test Tests conducted in cooperation between the manufacturer and the user in addition to routine tests and type tests. 3 Product terms 3.1 Power transformer 3.1.1 Transformer transfarmer GB/T 2900.15—1997 A stationary power converter that transfers electrical energy without changing the frequency of its AC power supply. 3.1.2 Power transformer power transformer A transformer that converts the AC voltage and current values of one power system into different voltage and current values of another power system to transmit electric energy.
3.1.3 Distribution transformer distributiontransformcr A transformer that reduces the voltage from a higher voltage to the final distribution voltage and is used directly for distribution. Oil-immersed transformer: nil-inmeredtypetransformer3.1.4
A transformer whose core and windings are immersed in insulating oil. 3.1.5 Dry-type transformer A transformer whose core and windings are not immersed in insulating oil. 3.1.6 Step-up transformer step-up transformer A transformer that increases one voltage level to another voltage level. 3.1.7 Step-down transformer step-down transformer A transformer that decreases one voltage level to another voltage level. 3.1.8 Boost transformer boostettransforner A transformer with a series winding that can change the line voltage and (or) phase and an excitation winding. Note: According to the relevant standards of the United States, its English name is \scrics ttansformer\3.1.9 Generator transformer genetatartransformer A power transformer directly connected to a generator. 3.1.10 System-interconnection transformer A power transformer used to connect two or more different transmission systems and can be used as a primary or secondary winding according to the changes in power flow.
3.1.11 Sealed transformer sealed transformer A non-breathing transformer that can avoid the exchange of substances inside the transformer and the external atmosphere. Note
1 In oil-immersed transformers, it can be installed or not to install gas manure +2 Sealed transformers can be divided into two categories
) The total volume of oil, air (or other gas) and their mixture inside the transformer remains unchanged throughout the operating temperature range, b) In the entire operating temperature range, the total volume of oil, air (or other gas) or their mixture inside the transformer changes and a sealed deformable container or deformable film bundle is used to adapt to this change. 3.1.12 Separate winding transformer separate winding transformer All windings have no common parts.
3.1.13 Two-winding transformer
two-windirng transformer
Each independent winding transformer has two windings connected to two voltage levels. 3.1.14 Multi-winding transformer multi-winding transformer Each independent winding transformer has multiple windings. 3.1.15 Auto-transformer A transformer with at least two windings having a common part. 3.1.16 Onload-tap-changing transformer
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