42 results about "Multiple zeros" patented technology

The invention discloses a zero-expansion dot matrix cylindrical shell structure used for a spacecraft and a design method thereof. According to the zero-expansion dot matrix cylindrical shell structure, a zero-expansion planar structure (5) is curved to form a cylinder, the zero-expansion planar structure (5) is obtained by spatially translating and interconnecting multiple zero-expansion basic cells (4) on a plane, each zero-expansion basic cell (4) is obtained by connecting four same micro-structures(3) at a top point, every two adjacent micro-structures (9) in each basic cell (4) are perpendicular to each other, and each micro-structure (3) is a triangle composed of a bottom edge (1) and two bevel edges (2). When the zero-expansion dot matrix cylindrical shell structure is designed, two different types of metal materials are selected to respectively serve as the material of the bottom edges (1) and the material of the bevel edges (2); then geometric dimension of the microstructure (3), the height and diameter of the zero-expansion dot matrix cylindrical shell structure (6), the number of basic cells in the annular direction, the number of basic cells in the height direction, the length of each bottom edge (1), the length of each bevel edge (2) and the section shape are designed in sequence; a finite element method is adopted for simulation; and a final design scheme is obtained through adjusting the length of each bottom edge (1) and the length of each bevel edge (2).

The invention includes: a bitstream updating output unit configured to receive a bitstream and update a syntax element located at a beginning of the bitstream according to a code length thereof and outputs the syntax element; a bitstream decoding unit configured to decode, in response to a decode request, a variable-length code of the syntax element outputted from the bitstream updating output unit; a zerosLeft updating unit configured to update zerosLeft based on a specific syntax element decoded by the bitstream decoding unit; a run_before remaining number updating unit configured to update a run_before remaining number based on a specific syntax element decoded by the bitstream decoding unit; and a syntax selection unit configured to select a syntax element to be decoded by the bitstream decoding unit. Thus, multiple zero run_before syntaxes and one non-zero run_before syntax, or multiple zero run_before syntaxes are decoded all at once.

A multi-stage, push-pull driven, resonant DC-AC converter ties the center-taps of primary windings of respective push-pull stages together, and drives each center-tap with a current source. Tying the center-taps of the primary windings of the respective DC-AC converters' transformers together forces the voltages at these locations to be the same, so as to achieve mutual resonant synchronization between the two stages. Connecting the center-taps to a current source provides the necessary power for each stage and allows for a variation in current between stages, as the center-tap voltages track one another. The tied-together center-tap voltage is monitored to obtain the zero voltage switching required for efficient operation of switching devices of each DC-AC converter stage.

The invention discloses a single-phase grounding leakage line selection method and device of the industrial and mineral low-tension electrical network. A single-phase leakage line selection module of the device comprises a zero-sequence fundamental-wave frequency-multiplication phase discriminating device, a zero-sequence voltage signal u0 processing circuit, a fault discriminating start voltage signal u0q processing circuit, a three-phase electrical network insulation level monitoring signal Ujy processing circuit and multiple zero-sequence current signal i0 processing circuit. According to the invention, frequency multiplication is directly carried out on the fundamental-wave zero-sequence current and voltage signals, the signals after frequency multiplication is sued for selecting and discriminating the single-phase grounding leakage fault, and such method is used for the first time domestically. Via the zero-sequence fundamental-wave frequency-multiplication phase discrimination method, selection time for the single-phase grounding leakage fault is shortened to less than or equivalent to 10ms which is greatly shorter than the protective motion time prescribed in the standard JB6314-92, and the technical problem that rapid and accurate leakage selection cannot be realized in the industrial and mineral low-tension multilevel electrical network with the zero-sequence reactor compensation function.

The invention provides a two-stage superconducting quantum interference apparatus's magnetic flux-voltage conversion device, method and application thereof. Through the amplification and combination of current's positive feedback and limiting amplification, the magnetic flux-voltage transfer rate is improved and the outputted magnetic amplitude is less than 2[phi]0, which avoids multiple zero points of transmission. At the same time, the SQUID magnetic detection module, using an under-feedback principle, achieves a magnetic flux detector that can realize self-reset and has a monotonic transfer characteristic to ensure that the outputted magnetic flux of the SQUID magnetic flux amplification module is conducted at a fixed operating point under a uniquely defined transmission characteristic for magnetic-voltage conversion and that the problem of multi-value transmission characteristics is addressed. The invention has the advantages that the two-stage SQUID amplifying module can improve the magnetic flux-voltage transmission rate and the single operating point cycle value in the transmission characteristic is obtained to avoid the multi-value problem; the operation is simple and the noise performance is improved greatly and can provide a practical high-performance SQUID magnetic sensor, thus a practical high-performance SQUID magnetic sensor can be formed.

The invention relates to a multi-tap electric reactor-based capacitive load power factor compensation circuit comprising a load voltage-current signal processing circuit and a compensation control and power supply circuit. To be specific, the multi-tap electric reactor-based capacitive load power factor compensation circuit is composed of a voltage transformer VS1, a current transformer CS1, a processor IC1, a drive chip IC2, a voltage-stabilized source module U0, an A solid-state relay U1, a B solid-state relay U2, a C solid-state relay U3, a D solid-state relay U4, an E solid-state relay U5, an F-solid state relay U6, a G solid-state relay U7, an electric reactor L1, a reference tube D1, an upper voltage-regulator tube D2, a lower voltage-regulator tube D3, and a load resistor R1 and the like. According to the invention, disturbance-free switch controlling is carried out on a power grid by using the multiple zero-crossing alternating-current solid-state relays and one multi-tap compensation reactor, thereby realizing multi-level compensation control of a power factor; and the requirements of power factor compensation control of most of capacitive loads can be met. Moreover, the provided circuit has advantages of high cost performance, good universality, and high security and reliability.

The invention relates to an access point voltage phase detection method of a line inductance based photovoltaic inverter by applying multiple zero-crossing points, which is simple, has small computation quantity, and can effectively detect the zero-crossing points and determine the phase of an actual grid voltage. The zero-crossing point moment of the actual gird voltage is accurately calculated through detecting before-and-after boundaries of the multiple zero-crossing point region by utilizing a unique characteristic that a multiple zero-crossing point region of the access point voltage wave form of the photovoltaic inverter is in strict bilateral symmetry on the zero-crossing points of the actual grid voltage, and further the specific phase at the current time in the grid voltage is determined .