Structure and Characteristics
The DSR-10 high-voltage electric energy meter consists of an epoxy resin fully cast weak output combination transformer and an electronic electric energy meter, which can be used outdoors or indoors. The transformer is installed on the high-voltage line at the measuring point, and the energy meter is installed in a safe and suitable place for observation.
The A-type high-voltage energy meter uses one A-type combination transformer, which includes two weak output current transformers and two weak output voltage transformers.
The B-type high-voltage energy meter uses two B-type combination transformers, which include one weak output current transformer and one weak output voltage transformer.
The accuracy of current transformers shall not be lower than level 0.2, and the accuracy of voltage transformers shall not be lower than level 0.5. The overall error of electric energy measurement shall not be less than 0.5S level. The DSR-10 high-voltage electric energy meter has the following advantages:
1) Electricity metering is more fair. The errors of high-voltage energy metering devices in the past were synthesized using the square root method through voltage transformers, current transformers, secondary lead voltage drops, and errors in energy meters. This error synthesis method is based on the assumptions of symmetry and uniformity, and can only be used as a qualitative reference quantity, and cannot define the accuracy level of electric energy metering devices. The error of high-voltage electric energy meters is verified by the high-voltage calibration table as a whole, just like low-voltage electric energy meters, which have clear error limits. Facilitating the implementation of metrological supervision.
2) Save a large amount of steel, copper, and insulation materials. The 10KV high-voltage electricity meter using weak output transformers consumes significantly less electricity than traditional metering devices due to the reduction in secondary load. In line with China's national policy of building a resource-saving society.
3) The anti-theft function is stronger. Traditional measuring boxes can only use closed secondary leads to prevent electricity theft. High voltage energy meters using weak output combination transformers can adopt measures such as enclosed secondary leads and enclosed primary current busbars. Because a single current can penetrate through a single turn, it is difficult to steal electricity by short circuiting the primary connector when the current bus is an insulated wire. For the act of stealing electricity by opening the meter box, the multifunctional energy meter has the functions of opening the box cover recording and time period recording. It also has records for meter reversal, abnormal electricity consumption curve, etc. For areas with higher requirements, the information transmission function of the multifunctional energy meter can be activated, sending information to the control center every hour through GPRS, receiving timely reports and processing.
In addition to stealing electricity by destroying measuring devices, another type of electricity loss is technical theft. According to the principle of an electric energy meter, electrical energy is obtained by integrating the time of electrical power, which is the product of voltage and current. The distortion of voltage in the power grid is usually not severe, usually not exceeding 5%, but the distortion of electric current tends to become increasingly severe. The distortion of current is caused by nonlinear components in the circuit, such as the thyristor speed control device of electric locomotives, the half wave temperature control device of electric heaters, the rectification device of electrolysis and electroplating plants, and the electric arc furnace of steelmaking plants. In these polluted power systems, the harmonic content in the current often exceeds 20%, including DC components. The product of the DC component, harmonic component, and the fundamental sine component of the voltage in the current is still a sine quantity, and the result of the periodic integration is zero. In other words, existing energy meters cannot measure the energy consumed by electricity consuming enterprises in terms of DC and harmonic components. The presence of DC component can also cause the iron core of the current transformer to saturate, resulting in a significant decrease in the equivalent magnetic permeability of the iron core and a sharp increase in AC error. According to some regional electricity balance statistics, in enterprises with severe harmonic pollution in the power grid, the power supply department loses more than 20% of the total electricity consumption. We conducted verification tests on the half wave current error of the current transformer, and the results showed that under half wave current, the ratio error of the 0.2 level current transformer reached -82% and the phase error reached 600 ′. For the fairness of electricity billing, it is necessary to use broadband current transformers that can pass through the DC component for users with severe harmonic pollution. The broadband current sensor equipped with high-voltage electric energy meters adopts a Hall and electromagnetic composite structure, ensuring that power grid losses can be avoided even in the event of intentional technical theft by users.
4) It will not cause ferromagnetic resonance. Voltage transformers on 10KV lines often experience ferromagnetic resonance with the line capacitance. When frequency division resonance occurs, a large excitation current is generated, which can burn out the voltage transformers. For measuring boxes equipped with fuses, burning the fuses can prevent the measurement of electrical energy, which can easily lead to measurement disputes. Compact voltage transformers have a primary DC resistance of up to 30K Ω, which reduces the Q value of the circuit to a level where resonance cannot occur.
The electrical structure of the SR-10 high-voltage electric energy meter is shown in Figure 1. In the figure, TV1 and TA1 are AB phase weak output combination transformers, TV2 and TA2 are CB phase weak output combination transformers, and DS is an electronic energy meter module that can measure active and reactive energy in both forward and reverse directions.

DSR-10 High Voltage Electric Energy Meter