수용가의 단상부하에 의한 전력계통 불평형 개선 연구

김영달,이재환,전시식 대한전기학회 2022 전기학회논문지 Vol.71 No.6

Electricity companies supply high-quality three-phase equilibrium power to capacity. However, a single phase load of the acceptor results in an amorphous power system. In design and construction, the single-phase load is distributed equally to each phase to minimize the inequality, but inequality is inevitable due to the different time zones of use of many unspecified loads. In the acceptance area, a separate single-phase transformer is installed to supply single-phase power to minimize three-phase inequality, but installation costs and installation spaces such as single-phase transformers and special high-pressure breakers are required. To improve this irrationality, this paper aims to supply single-phase power by introducing an open△ inverse connection method to the transformer tertiary side. The second side of the three-wheel transformer supplies three-phase equilibrium power, and the third side supplies single-phase power by open△reverse connections. Compared to the single-phase power supply method by a single-phase transformer, the quantity and loss of cables on the high-pressure and low-pressure sides are the same, and special high-pressure breakers and single-phase transformers are not required. This is in accordance with the government's energy saving policy and is expected to contribute to the development of the electricity industry by reorganizing related laws and regulations so that it can be applied to the site through active review and verification.

Control Strategies of Active Power Line Conditioners in Single-Phase Circuits

Toshihiko Tanaka,Masayuki Okamoto,Eiji Hiraki 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

This paper deals with two control strategies for the active power line conditioners in single-phase circuits. The first one is a constant dc capacitor voltage control based strategy, which is commonly used in the active power line conditioners. Any detection blocks of the fundamental active, reactive, and harmonic components are not necessary in this method. Thus we offer the simplest way to compensate the fundamental reactive and harmonic currents on the source-side. The other is a reactive power control based strategy, which is with the correlation and cross-correlation coefficients between the feeder voltage and load current. Controlling the detected fundamental reactive component with the cross-correlation coefficient on the source-side reduces the capacity of the PWM inverter, which performs the active power line conditioners. The basic principles of the proposed control strategies are discussed in detail, and then applied to the single-phase active power line conditioners in single-phase based distribution systems. These sigle-phase distributin systems are used in the single-phase three-wire systems and electrified railways. The validity and excellent practicability of the proposed control strategies are confirmed by experimental results.

Static VAR Compensator-Based Voltage Regulation for Variable-Speed Prime Mover Coupled Single- Phase Self-Excited Induction Generator

Ahmed, Tarek,Noro, Osamu,Sato, Shinji,Nakaoka, Mutsuo The Korean Institute of Power Electronics 2003 JOURNAL OF POWER ELECTRONICS Vol.3 No.3

In this paper, the single-phase static VAR compensator (SVC) is applied to regulate and stabilize the generated terminal voltage of the single-phase self-excited induction generator (single-phase SEIG) driven by a variable-speed prime mover (VSPM) under the conditions of the independent inductive load variations and the prime mover speed changes The conventional fixed gain PI controller-based feedback control scheme is employed to adjust the equivalent capacitance of the single-phase SVC composed of the fixed excitation capacitor FC in parallel with the thyristor switched capacitor TSC and the thyristor controlled reactor TCR The feedback closed-loop terminal voltage responses in the single-phase SEIG coupled by a VSPM with different inductive passive load disturbances using the single-phase SVC with the PI controller are considered and discussed herem. A VSPM coupled the single-phase SEIG prototype setup is established. Its experimental results are illustrated as compared with its simulation ones and give good agreements with the digital simulation results for the single-phase SEIG driven by a VSPM, which is based on the SVC voltage regulation feedback control scheme.

Single-phase Active Power Filter Based on Rotating Reference Frame Method for Harmonics Compensation

Jin-Sun Kim,Young-Seok Kim 대한전기학회 2008 Journal of Electrical Engineering & Technology Vol.3 No.1

This paper presents a new control method of single-phase active power filter (APF) for the compensation of harmonic current components in nonlinear loads. To facilitate the possibility of complex calculation for harmonic current detection of the single phase, a single-phase system that has two phases was constructed by including an imaginary second-phase giving time delay to the load current. The imaginary phase, which lagged the load current T/4 (Here T is the fundamental cycle) is used in the conventional method. But in this proposed method, the new signal as the second phase is delayed by the filter. Because this control method is applied to a single-phase system, an instantaneous calculation was developed by using the rotating reference frames synchronized to source-frequency rather than by applying instantaneous reactive power theory that uses the conventional fixed reference frames. The control scheme of single-phase APF for the current source with R-L loads is applied to a laboratory prototype to verify the proposed control method.

분리된 삼상 자속구속형 전류제한기와 일체화된 삼상 자속구속형 전류제한기의 전류제한 특성 비교

두승규,두호익,김민주,박충렬,김용진,이동혁,한병성,Doo, Seung-Gyu,Du, Ho-Ik,Kim, Min-Ju,Park, Chung-Ryul,Kim, Yong-Jin,Lee, Dong-Hyeok,Han, Byoung-Sung 한국전기전자재료학회 2009 전기전자재료학회논문지 Vol.22 No.8

We investigate the comparison of fault current characteristics between the separates three-phase flux-lock type superconducting fault current limiter(SFCL) and integrated three-phase flux-lock type superconducting fault current limiter(SFCL). The single-phase flux-lock type SFCL consists of two coils. The primary coil is wound in parallel to the secondary coil on an iron core and superconducting elements are connected to secondary coil in series. Superconducting elements are used by the YBCO coated conductor. The separated three-phase flux-lock type SFCL consists of single-phase flux-phase type SFCL in each phase. But the integrated three-phase flux-lock type SFCL consists of three-phase flux-reactors wound on an iron core. Flux-reactor consists of the same turn's ratio between coil 1 and coil 2 for each single phase. To compare the current limiting characteristics of the separated three-phase flux-lock type SFCL and integrated three-phase flux-lock type SFCL, the short circuit experiments are carried out fault condition such as the single line-to-ground fault. The experimental result shows that fault current limiting characteristic of the separated three-phase flux-lock type SFCL was better than integrated three-phase flux-lock type SFCL. And the integrated three-phase flux-lock type SFCL has an effect on sound phase.

Single-Phase Z-Source AC/AC Converter with Wide Range Output Voltage Operation

Minh-Khai Nguyen,Young-Gook Jung,Young-Cheol Lim 전력전자학회 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.5

A new type of single-phase Z-source AC/AC converter based on a single-phase matrix converter is proposed in this paper. The proposed single-phase Z-source AC/AC converter has unique features; namely that the output voltage can be bucked and in-phase/out-of-phase with the input voltage; that the output voltage can be boosted and in-phase/out-of-phase with the input voltage. The converter employs a safe-commutation strategy to conduct along a continuous current path, which results in the elimination of voltage spikes on switches without the need for a snubber circuit. The operating principles of the proposed single-phase Z-source AC/AC converter are described, and a circuit analysis is provided. To verify the performance of the proposed converter, a laboratory prototype based on a TMS320F2812 DSP was constructed. The simulation and the experimental results verified that the output voltage can be bucked-boosted and in-phase with the input voltage, and that the output voltage can be bucked-boosted and out-of-phase with the input voltage.

Single-phase Active Power Filter Based on Rotating Reference Frame Method for Harmonics Compensation

Kim, Jin-Sun,Kim, Young-Seok The Korean Institute of Electrical Engineers 2008 Journal of Electrical Engineering & Technology Vol.3 No.1

This paper presents a new control method of single-phase active power filter (APF) for the compensation of harmonic current components in nonlinear loads. To facilitate the possibility of complex calculation for harmonic current detection of the single phase, a single-phase system that has two phases was constructed by including an imaginary second-phase giving time delay to the load current. The imaginary phase, which lagged the load current T/4 (Here T is the fundamental cycle) is used in the conventional method. But in this proposed method, the new signal as the second phase is delayed by the filter. Because this control method is applied to a single-phase system, an instantaneous calculation was developed by using the rotating reference frames synchronized to source-frequency rather than by applying instantaneous reactive power theory that uses the conventional fixed reference frames. The control scheme of single-phase APF for the current source with R-L loads is applied to a laboratory prototype to verify the proposed control method.

Single-Phase Self-Excited Induction Generator with Static VAR Compensator Voltage Regulation for Simple and Low Cost Stand-Alone Renewable Energy Utilizations Part I : Analytical Study

Ahmed, Tarek,Noro, Osamu,Soshin, Koji,Sato, Shinji,Hiraki, Eiji,Nakaoka, Mutsuo The Korean Institute of Electrical Engineers 2003 KIEE International Transactions on Power Engineeri Vol.a3 No.1

In this paper, the comparative steady-state operating performance analysis algorithms of the stand-alone single-phase self-excited induction generator (SEIG) is presented on the basis of the two nodal admittance approaches using the per-unit frequency in addition to a new state variable de-fined by the per-unit slip frequency. The main significant features of the proposed operating circuit analysis with the per-unit slip frequency as a state variable are that the fast effective solution could be achieved with the simple mathematical computation effort. The operating performance results in the simulation of the single-phase SEIG evaluated by using the per-unit slip frequency state variable are compared with those obtained by using the per-unit frequency state variable. The comparative operating performance results provide the close agreements between two steady-state analysis performance algorithms based on the electro-mechanical equivalent circuit of the single-phase SEIG. In addition to these, the single-phase static VAR compensator; SVC composed of the thyristor controlled reactor; TCR in parallel with the fixed excitation capacitor; FC and the thyristor switched capacitor; TSC is ap-plied to regulate the generated terminal voltage of the single-phase SEIG loaded by a variable inductive passive load. The fixed gain PI controller is employed to adjust the equivalent variable excitation capacitor capacitance of the single-phase SVC.

Single-Phase Z-Source AC/AC Converter with Wide Range Output Voltage Operation

Nguyen, Minh-Khai,Jung, Young-Gook,Lim, Young-Cheol The Korean Institute of Power Electronics 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.5

A new type of single-phase Z-source AC/AC converter based on a single-phase matrix converter is proposed in this paper. The proposed single-phase Z-source AC/AC converter has unique features; namely that the output voltage can be bucked and in-phase/out-of-phase with the input voltage; that the output voltage can be boosted and in-phase/out-of-phase with the input voltage. The converter employs a safe-commutation strategy to conduct along a continuous current path, which results in the elimination of voltage spikes on switches without the need for a snubber circuit. The operating principles of the proposed single-phase Z-source AC/AC converter are described, and a circuit analysis is provided. To verify the performance of the proposed converter, a laboratory prototype based on a TMS320F2812 DSP was constructed. The simulation and the experimental results verified that the output voltage can be bucked-boosted and in-phase with the input voltage, and that the output voltage can be bucked-boosted and out-of-phase with the input voltage.

단상 변압기 지그재그 결선에 의한 3고조파 전류 저감 효과 분석

김종겸(Jong-Gyeum Kim),김지명(Ji-Myeong Kim) 대한전기학회 2017 전기학회논문지 P Vol.66 No.3

The three-phase four-wire power distribution system can be used to supply power to single-phase and three-phase loads at the same time. There are linear loads and nonlinear loads as single-phase loads connected to each phase. The nonlinear load generates a harmonic current during the power energy conversion process. In particular, the single-phase nonlinear load has a higher proportion of generation of the third harmonic current than the harmonics of the other orders. In a three-phase four-wire system, the third harmonic current flows through the neutral wire to the power supply side, affecting the power supply side and the line. Furthermore, the magnitude of the current flowing in the neutral line can be higher than the current flowing in the individual phase. If the neutral current is higher than the phase current, the breaker may be blocked. Therefore, it is necessary to reduce the amount of current flowing in the neutral line by harmonics. There is a method of zigzag connecting a single phase transformer by a method of reducing 3 harmonic current. In this study, the method of reducing the magnitude of the three harmonic currents flowing through the zigzag wire by comparing the polarity and the negative polarity characteristics of the single phase transformer was compared through measurement and simulation.