1363464 九、發明說明： 【發明所屬之技術領域】 本發明涉及一種不間斷電源裝置，尤指一種改進 的在線式不間斷電源裝置。 【先前技術】1363464 IX. Description of the Invention: [Technical Field] The present invention relates to an uninterruptible power supply device, and more particularly to an improved online uninterruptible power supply device. [Prior Art]
不間斷電源（UPS)是一種交流電源供應器，其可 以在市電不正常時瞬間提供交流電。目前，習知的在 鲁線式不間斷電源裝置’採用交流-直流、直流-交流的 雙轉換裝置，請參看第4圖所示。市電輸入先由濾波 裝置（111)進行濾波，再經過保險絲（112)超載保護， 再由二相全橋整流裝置（113)整流，經電容濾波裝置 (115)濾成直流電壓，電池裝置（114)也經過三相全橋 整流裝置（113 )提供直流電壓，經過保險絲（116 )送到 逆變裝置（117)，將直流電壓用SPWM (SINEWAVEpuLSE • WIDTH MODULATION)控制技術經工頻變壓器隔離升壓 產生正弦波電壓，經過繼電裝置（118)輸出淨化的交 流電源再經過濾波裝置（119)濾波後輸出到用戶端供 電。但疋習知的（請參看第4圖所示）不間斷電源（υρς) 整機滿負荷運行效率約80%〜85%，輕载時效率更低， 並且轉換損粍太多功率。 【發明内容】 本發明的一個目的在於提供一種改進的在線式 5 1363464 不間斷電源裝置’通過直流/直流轉換裝置，將經整 流的直流電壓轉換為正弦波脈寬直流電壓，只在直流 /直流轉換裝置中利用了一次電力轉換實現將輸入電 壓轉換為正弦波脈寬直流電壓，經直流/交流轉換裝 置輸出正弦波脈寬交流電壓。 為實現本發明的上述目的，本發明的在線式不間 斷電源包括： 一交流輸入，耦合於市電輸入端； 一交流輸出，耦合於負載端； 一整流裝置，其輸入端耦合於交流輸入，用來將 輸入的交流電壓整流輸出； 一直流電源，並聯耦合於該整流裝置的輸出端， 用來在市電停電時提供直流電壓； 一矽控開關，電連接於該直流電源的輸出端，該 開關裝置導通時該直流電源供電； 一直流/直流轉換裝置，其輸入端耦合於整流裝An uninterruptible power supply (UPS) is an AC power supply that provides AC power instantaneously when utility power is not normal. At present, the conventional U-wire uninterruptible power supply unit uses an AC-DC, DC-AC double conversion device, as shown in Figure 4. The mains input is first filtered by the filtering device (111), then overloaded by the fuse (112), rectified by the two-phase full-bridge rectifying device (113), filtered into a DC voltage by the capacitive filtering device (115), and the battery device (114) The DC voltage is also supplied to the inverter device (117) via the three-phase full-bridge rectifier (113), and the DC voltage is isolated and boosted by the SPWM (SINEWAVEpuLSE • WIDTH MODULATION) control technology via the power frequency transformer. A sinusoidal voltage is generated, and the purified AC power is outputted by the relay device (118), filtered by the filtering device (119), and output to the user terminal for power supply. However, it is known (see Figure 4) that the uninterruptible power supply (υρς) operates at a full load of about 80% to 85%, is less efficient at light loads, and converts too much power. SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved in-line 5 1363464 uninterruptible power supply unit 'converting a rectified DC voltage into a sinusoidal pulse width DC voltage through a DC/DC converter, only in DC/DC The conversion device utilizes a primary power conversion to convert the input voltage into a sinusoidal pulse width DC voltage, and outputs a sinusoidal pulse width AC voltage via the DC/AC conversion device. To achieve the above object of the present invention, the online uninterruptible power supply of the present invention comprises: an AC input coupled to the mains input; an AC output coupled to the load; a rectifying device having an input coupled to the AC input for use The input AC voltage is rectified and outputted; a DC power source is coupled in parallel to the output end of the rectifying device for providing a DC voltage when the mains is powered off; a control switch electrically connected to the output end of the DC power supply, the switch The DC power supply is provided when the device is turned on; a DC/DC conversion device whose input end is coupled to the rectifying device
以及分別耦合於該初級端的兩 個繞組的第一 功率㈣’該次級端包 6 括兩個繞組’以及分別_合於該次級端的兩個繞組的 第二功率開關和第四功率開關； 直教/交流轉換裝置，其輸入端耦合於該直流/ 直机轉換裝置的輪出端，輸出端耦合於該交流輸出， 該直机/交流轉換裝置包括四個由處理器控制的功率 開關和一低通濾波器； 繼電器轉合於乂流輸出端，用來切換市電供 電與該不間斷電源裝置供電；以及 處理器，用來控制該第一與第三功率開關交替 導通與關斷、第二與第四功率開關交替導通與關斷； 該直流/直流轉換裝置由該處理器控制，將輸入 的直机電壓轉換為正弦波脈寬直流電壓，經該直流/ 交流轉換裝置輪出正弦波脈寬交流電壓，再進行濾波 後輸出。 由於採用了上述的技術方案，本發明的在線式不 1斷電源裝置利用直流/直流轉換裝置將經整流的直 机電壓轉換為正弦波脈寬直流電壓，經直流/交流轉 換裝置輸出正弦波脈寬交流電壓，只在直流/直流轉 換I置中利用了電力轉換’減少了轉換功率損耗。 本發明的另一個目的在於提供一種改進的在線 弋不間斷電源，其利用直流/直流轉換裝置將負載側 1363464 或者直流/交流轉換裝置產生的多餘能量送回直流電 源儲能。 為實現本發明的上述目的，該直流/直流轉換裝 置還包括一充電電路，該充電電路包括一降壓變壓 器、一電容和一二極管，該降壓變壓器包括一初級端 和一次級端，其中該降壓變壓器初級端即為該升壓變 壓器次級端’該降壓變壓器次級端包括一繞組，該直 流/直流轉換裝置通過該充電電路將負載侧或者直流 / 乂流轉換裝置產生的多餘能量送回直流電源儲能。 由於採用了該技術方案’該在線式不間斷電源裝 置在負載側或者直流/交流轉換裝置產生的多餘能量 時’可將多餘能量送回直流電源儲能從而達到節能的 目的。 【實施方式】 以下’根據附圖對本發明的最佳實施形態邊行說 明。 第1圖是根據本發明一較佳具體實施例的在線式 不間斷電源裝置的結構方塊示意圖。該較佳具體實施 例的在線式不間斷電源裝置包括： 一濾、波裝置（1)’耦合於交流輸入端，用來對輸 入的市電進行濾波； 一整流裝置（2)，其輸入端耦合於濾波裝置（1)的 8 1363464 輸出端，用來將經濾波的市電整流輸出； 一電池裝置（3)，並聯耦合於該整流裝置（2)的輸 出端’用來在市電停電時提供直流電壓； 一矽控開關（4)，電連接於該電池裝置（3)，該梦 控開關（4)導通時電池裝置（3)供電； 直、"IL /直流轉換裝置（5 )’其輸入端輕合於整流 裝置（2)的輸出端； 一直流/交流轉換裝置（6)，其輸入端耦合於直流 /直流轉換裝置（5)的輸出端； 一繼電器（7)，耦合於交流輸出端，用來切換市 電供電與該不間斷電源裝置供電； 一濾波裝置（8),耦合於該在線式不間斷電源裝 置的輸出端，用來將輸出的電壓經濾波，供給用戶端 設備；以及 一處理器，用來控制直流/直流轉換裝置（5)、直 流/交流轉換裝置（6)及繼電器（7)的切換。 更具體地，該直流/直流轉換裝置（5)包括一升壓 變壓器’由繞組(51)(52)與第一功率開關(56)、第二 功率開關（57)組成推挽式電路初級端，其導通占空比 小於50%’並由繞組（53)(54)與第三功率開關（58)、 第四功率開關⑽組成次級端並聯輸出，用來將輸入 1363464 的直流電壓轉換為正弦波脈寬直流電壓輸出。當負載 侧或交流/直流轉換裝置（6)工作時產生多餘能量 時，第三功率開關（58)、第四功率開關（59)導通將能 • 量送回降壓變壓器次級端繞組（55)經二極管（5〇1)， . 濾波電容（502)，將能量儲存到電池裝置（3)。由於要 產生的SPWM信號導通占空比大於5〇%，所以由第一功 率開關（56)、第二功率開關（57)各導通一半再經過 • (53、54)繞組相加輸出合成_信號，當不考慮轉 換效率時，為降低成本也可以用二極管代替第三功率 開關（58)、第四功率開關（59)〇可以設定第一功率開 關(56)與第三功率開關(58)同步導通，第二功率開關 (57)與第四功率開關（59)同步導通，降低功率開關導 通時電壓降，提高效率。 該直流/交流轉換裝置⑻，&括四個功率開關 •⑽⑽）⑽（64)，以及由一電感（65)與一電容⑽ 組成的用來進行據波的低通遽波器。利用處理器控制 功率開關（61 )(62) (63)(64)的導通與關斷，功率開 關（61)(62)導通產生正半周的卯龍電壓波形，功率 開關（63)(64)導通產生負半周的SPWM電壓波形，將 從直流/直流轉換裝置(5)輸出的正弦波脈寬直流電 壓經四個功率開關⑽⑽⑽（64)輸出為正弦波 1363464 脈寬交流電壓。 本發明的在線式不間斷電源（UPS),不受市電電 源品質的影響。當市電正常時，市電直接由濾波裝置 (1)濾波經繼電器（7)、濾波裝置（8 )輸出到用戶端； 當電壓過高或過低時，由該在線式不間斷電源裝置提 供純淨的交流電源；當市電停電時無中斷時間轉由電 池裝置（3)提供能量繼續提供純淨的交流電源。 當市電過高或過低時，矽控開關（4)斷開，由處 理器控制繼電器（7 )切換到該在線式不間斷電源供 電。市電輸入從滤波裝置（1)經整流裝置（2)，將交流 電整流成只有正值的市電頻率兩倍的正弦波（請參看 第2圖所示的參考波形17)，提供給直流/直流變換器 (5)的升壓變壓器初級端繞組（51)(52)，由處理器控 制第一功率開關（56)、第二功率開關（57)交替導通產 生高頻率脈波電壓（請參閱第2圖所示的參考波形 12、13)’為避免變壓器飽合’限制升壓變屋器初級 端繞組（51)(52)的最大占空比不大於5〇%，經過升壓 變壓器隔離升壓到次級端繞組（53)(54)，將波形相加 合成真正的正弦波脈寬直流電壓（請參看第2圖所示 的參考波形14)(由處理器計算每一正弦波脈寬的值 除以一，做為第一功率開關（5 6 )、第二功率開關（5 7 ) 11 1363464 - 的開關控制信號），再將正弦波脈寬高頻直流電壓經 直流/交流轉換裝置（6)產生低頻（5〇Hz/6〇Hz)正弦波 脈寬交流電壓，處理器控制功率開關(61)(62)導通時 產生正半周（请參閲第2圖所示的參考波形6162)，處 •理器控制功率開關（63)(64)導通時產生負半周（請參 閱第2圖所禾的參考波形6364)，直流/交流轉換裝置 ⑻將從直流/直流轉換裝置（5)輸出的正弦波脈寬直 •流電壓經四個功率開關（61 )(62)(63)⑽輸出為正 ' 弦波脈寬交流電壓（請參閲第2圖所示的參考波形 • 15)，然後經過電感器（65)與電容器（66)組成的低通 濾波器濾除高頻成份輸出純淨低頻正弦波交流電壓 (請參閱第2圖所示的參考波形16)，再經過繼電器（7) 輸出，經濾波裝置（8)濾除諧波後提供給用戶設備繼 續供電。其中第三功率開關（58)導通時間與第一功率 開關（56)的導通同步，第四功率開關（59)導通時間與 第：功率_ (57)的導通同步，可降低功率開關能量 知耗，也可以用二極管取代第三功率開關（58)、第四 功率開關（59)，降低成本。為了將負载側或直流/交 流轉換裝置⑹產生的多餘能量送回電池端儲能，第 二功率開關（58)與第四功率開關（59)導通，將能量送 回降壓變壓器次級端繞組(55)經二極管⑸"濾波電 12 1363464 容（502)將多餘能量送回電池儲能’並對電池裝置（3) 充電。 市電停電時’由處理器控制繼電器（7)切換到該 不間斷裝置中的電池裝置（3)供電。矽控開關（4)導 通’電池裝置（3)輸出電壓（請參閱第3圖所示的參考 波形11)，提供給直流/直流變換器（5)的升壓變壓器 初級端繞組（51)(52)，由處理器控制第一功率開關 (56)、第一功率開關（57)交替導通產生高頻脈波電壓 (請參看第3圖所示的參考波形12、13)，為避免變壓 器飽合’限制升壓變壓器初級端繞組（51)(52)的最大 占空比不大於50% ’經過升壓變壓器隔離升壓到次級 端繞組（53)(54) ’將波形相加合成真正的正弦波脈寬 尚頻直流電壓（請參閱第3圖所示的參考波形丨4)(由 處理器處理器計算每一正弦波脈寬的值除以二，做為 第一功率開關（56) '第二功率開關（57)的開關控制信 號）’再將正弦波脈寬高頻直流電壓經過直流/交流轉 換裝置（6)產生低頻（50Hz/60Hz)正弦波交流電壓，處 理器控制功率開關（61)(62)導通時產生正半周（請參 看第3圖所示的參考波形6162)，處理器控制功率開 關（63)(64)導通時產生負半周（請參看第3圖所示的 參考波形6364)，直流/交流轉換裝置（6)將從直流/ 13 1363464 直流轉換裝置（5)輸出的正弦波脈寬高頻直流電壓經 四個功率開關（61)(62)(63)(64)輸出為正弦波脈寬 父流電壓（請參看圖示的參考波形15)，然後經過電感 器（65)與電容器（66)組成的低通濾波器濾除高頻成 份輸出純淨低頻正弦波交流電壓（請參看第3圖所示 的參考波形16)，再經過繼電器（7)輸出，經濾波裝置 (8 )濾除諧波後提供給用戶設備繼續供電。 可以理解的是，上述實施例的詳細說明是為了闡 述和解釋本發明的原理而不是對本發明的保護範圍 的限疋。在不脫離本發明的主旨的前提下，本領域的 一般技術人員通過對上述技術方案的所教導的原理 的理解可以在；些實施例基礎上做出修改，變化和改 動°因此本發明的保護範圍由所附的權利要求以及其 等同來限定。 【圖式簡單說明】 第1圖為本發明一較佳具體實施例的在線式不間 斷電源裝置的結構方塊示意圖。 第2圖為本發明一較佳具體實施例的在線式不間 斷電源裝置在有市電時各點的輸出波形示意圖。 第3圖為本發明一較佳具體實施例的在線式不間 斷電源裝置在電池裝置供電時各點的輸出波形示意 14 1363464 圖。 第4圖為習知的在線式不間斷電源裝置的結構方 框示意圖》 【主要元件符號說明】 (2)整流裝置 (4)矽控開關 (6 )直流/交流轉換裝置 (8)濾波裝置 (56)第一功率開關 (58)第三功率開關 (1)濾波裝置 ’ (3)電池裝置 (5)直流/直流轉換裝置 (7)繼電器 ^ (51 )(52)(53)(54)(55)繞組 (57)第二功率開關 (59)第四功率開關 (61)(62)(63)(64)功率開關 (65)電感 （66)電容 (501)二極管 （502)濾波電容 (111)遽波裝置 （112)保險絲 • (113)三相全橋整流裝置 （114)電池 • (115)遽波裝置 （116)保險絲 (117)逆變裝置 （118)繼電裝置 (119)濾波裝置 15And a first power (four) of the two windings respectively coupled to the primary end, the secondary end package 6 includes two windings' and a second power switch and a fourth power switch respectively constituting two windings of the secondary side; a direct teaching/AC conversion device having an input coupled to a wheel end of the DC/DC converter, an output coupled to the AC output, the DC/AC conversion device including four processor-controlled power switches and a low pass filter; a relay coupled to the choke output terminal for switching the mains supply and the uninterruptible power supply; and a processor for controlling the first and third power switches to be alternately turned on and off, The second and fourth power switches are alternately turned on and off; the DC/DC converter is controlled by the processor to convert the input straight machine voltage into a sinusoidal pulse width DC voltage, and the sine wave is rotated by the DC/AC conversion device The pulse width AC voltage is filtered and output. By adopting the above technical solution, the online unpowered power supply device of the present invention converts the rectified straight machine voltage into a sinusoidal pulse width DC voltage by using a DC/DC conversion device, and outputs a sine wave via a DC/AC conversion device. Wide AC voltage, which utilizes power conversion only in DC/DC conversion I, reduces conversion power loss. Another object of the present invention is to provide an improved in-line, uninterruptible power supply that utilizes a DC/DC converter to return excess energy generated by the load side 1363464 or the DC/AC converter to the DC power source. In order to achieve the above object of the present invention, the DC/DC conversion device further includes a charging circuit including a step-down transformer, a capacitor and a diode, the step-down transformer including a primary end and a primary end, wherein the The primary end of the step-down transformer is the secondary end of the step-up transformer. The secondary end of the step-down transformer includes a winding through which the DC/DC converter transmits excess energy generated by the load side or the DC/turbulent converter. Return the DC power storage. Due to the adoption of the technical solution, the on-load uninterruptible power supply device can send excess energy back to the DC power storage to save energy when the excess energy generated by the load side or the DC/AC conversion device is used. [Embodiment] Hereinafter, the best mode for carrying out the invention will be described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram showing the construction of an in-line uninterruptible power supply unit in accordance with a preferred embodiment of the present invention. The online uninterruptible power supply device of the preferred embodiment comprises: a filter, wave device (1)' coupled to the AC input for filtering the input mains; and a rectifying device (2) coupled to the input thereof At the 8 1363464 output of the filtering device (1) for outputting the filtered mains rectification; a battery device (3) coupled in parallel to the output of the rectifying device (2) for providing a DC when the mains is out of power Voltage; a control switch (4) electrically connected to the battery device (3), the battery device (3) is powered when the dream switch (4) is turned on; the straight, "IL/DC converter device (5)' The input end is lightly coupled to the output of the rectifying device (2); a DC/AC converting device (6) having an input coupled to the output of the DC/DC converting device (5); a relay (7) coupled to the AC The output end is used for switching the power supply of the mains and the power supply of the uninterruptible power supply device; a filtering device (8) coupled to the output end of the online uninterruptible power supply device for filtering the output voltage to the user equipment; And a processor, It is used to control the switching of DC/DC converter (5), DC/AC converter (6) and relay (7). More specifically, the DC/DC conversion device (5) includes a step-up transformer 'the primary end of the push-pull circuit formed by the winding (51) (52) and the first power switch (56) and the second power switch (57) The turn-on duty ratio is less than 50%' and is output in parallel with the secondary end of the winding (53) (54) and the third power switch (58) and the fourth power switch (10) for converting the DC voltage of the input 1363464 into Sinusoidal pulse width DC voltage output. When excess energy is generated when the load side or AC/DC converter (6) is operating, the third power switch (58) and the fourth power switch (59) are turned on to return the voltage to the secondary winding of the step-down transformer (55). The energy is stored in the battery device (3) via a diode (5〇1), . filter capacitor (502). Since the SPWM signal to be generated has an on-duty ratio greater than 5〇%, the first power switch (56) and the second power switch (57) are each turned on and then passed through the (53, 54) windings to add the output synthesis_signal. When the conversion efficiency is not considered, in order to reduce the cost, the diode can be used instead of the third power switch (58) and the fourth power switch (59), and the first power switch (56) can be set to be synchronized with the third power switch (58). When turned on, the second power switch (57) and the fourth power switch (59) are turned on synchronously to reduce the voltage drop when the power switch is turned on, thereby improving efficiency. The DC/AC conversion device (8), & includes four power switches • (10) (10)) (10) (64), and a low-pass chopper that is composed of an inductor (65) and a capacitor (10) for performing a wave. The processor is used to control the on and off of the power switch (61) (62) (63) (64), and the power switch (61) (62) is turned on to generate a positive half cycle of the Snapdragon voltage waveform, the power switch (63) (64) The turn-on produces a negative half cycle SPWM voltage waveform, and the sinusoidal pulse width DC voltage output from the DC/DC converter (5) is output as a sine wave 1363464 pulse width AC voltage through four power switches (10)(10)(10)(64). The online uninterruptible power supply (UPS) of the present invention is not affected by the quality of the commercial power supply. When the mains is normal, the mains is directly filtered by the filtering device (1) via the relay (7) and the filtering device (8) to the user terminal; when the voltage is too high or too low, the online uninterruptible power supply device provides pure AC power; when the mains is out of power, no interruption time is transferred to the battery device (3) to provide energy to continue to provide pure AC power. When the mains is too high or too low, the remote control switch (4) is turned off, and the processor control relay (7) switches to the online uninterruptible power supply. The mains input is filtered from the filtering device (1) via the rectifying device (2) to rectify the alternating current into a sine wave with twice the positive mains frequency (see reference waveform 17 shown in Figure 2) for DC/DC conversion. The booster transformer primary-side winding (51) (52) of the device (5) is controlled by the processor to alternately conduct the first power switch (56) and the second power switch (57) to generate a high-frequency pulse wave voltage (see the second The reference waveforms 12, 13) shown in the figure 'To avoid transformer saturation' limit the maximum duty cycle of the primary winding (51) (52) of the boost converter to be no more than 5〇%, and the boost is isolated by the step-up transformer. To the secondary winding (53) (54), add the waveforms to form a true sinusoidal pulse width DC voltage (see reference waveform 14 shown in Figure 2) (the sine wave pulse width is calculated by the processor) The value is divided by one, as the first power switch (5 6 ), the second power switch (5 7 ) 11 1363464 - the switch control signal), and then the sine wave pulse width high frequency DC voltage is passed through the DC/AC conversion device ( 6) Generate low frequency (5〇Hz/6〇Hz) sine wave pulse width AC voltage, processor control function When the rate switch (61) (62) is turned on, a positive half cycle is generated (refer to reference waveform 6162 shown in Figure 2), and the processor controls the power switch (63) (64) to generate a negative half cycle when turned on (see section 2 reference frame 6364), the DC/AC conversion device (8) outputs a sinusoidal pulse width straight current from the DC/DC converter (5) through four power switches (61) (62) (63) (10) The output is a positive 'sine wave pulse width AC voltage (refer to the reference waveform shown in Figure 2 • 15), and then a low-pass filter consisting of an inductor (65) and a capacitor (66) filters out high frequency components. Output pure low frequency sine wave AC voltage (refer to reference waveform 16 shown in Figure 2), and then output through the relay (7), filter the harmonics through the filter device (8) and provide power to the user equipment. The conduction time of the third power switch (58) is synchronized with the conduction of the first power switch (56), and the conduction time of the fourth power switch (59) is synchronized with the conduction of the first power: (57), which can reduce the energy consumption of the power switch. It is also possible to replace the third power switch (58) and the fourth power switch (59) with a diode to reduce the cost. In order to send excess energy generated by the load side or the DC/AC conversion device (6) back to the battery end energy storage, the second power switch (58) and the fourth power switch (59) are turned on, and the energy is sent back to the secondary winding of the step-down transformer. (55) The battery (3) is charged by the diode (5) "filtering power 12 1363464 capacity (502) to return excess energy back to the battery storage device'. When the utility power is cut off, the processor control relay (7) switches to the battery device (3) in the uninterrupted device to supply power. The tamper switch (4) turns on the 'battery unit (3) output voltage (see reference waveform 11 shown in Figure 3) and supplies the step-up transformer primary winding (51) to the dc/dc converter (5) ( 52), the first power switch (56) is controlled by the processor, and the first power switch (57) is alternately turned on to generate a high frequency pulse wave voltage (refer to the reference waveforms 12 and 13 shown in FIG. 3), in order to avoid the transformer full. The 'maximum duty cycle of the primary winding of the step-up transformer (51) (52) is not more than 50% 'Isolated by the step-up transformer to boost the secondary winding (53) (54) 'Add the waveforms to the real The sinusoidal pulse width is still DC voltage (see reference waveform 丨4 shown in Figure 3) (the value of each sine wave pulse width is divided by two by the processor processor as the first power switch (56) 'The switch control signal of the second power switch (57)' then sinusoidal pulse width high frequency DC voltage is generated by the DC/AC conversion device (6) to generate a low frequency (50Hz/60Hz) sine wave AC voltage, and the processor controls the power. The positive half cycle is generated when the switch (61) (62) is turned on (refer to the reference shown in Figure 3). Shape 6162), the processor controls the power switch (63) (64) to generate a negative half cycle when turned on (see reference waveform 6364 shown in Figure 3), and the DC/AC converter (6) will convert from DC / 13 1363464 DC The sine wave pulse width high frequency DC voltage output by the device (5) is output as a sine wave pulse width parental voltage through four power switches (61) (62) (63) (64) (refer to the reference waveform 15 shown in the figure) Then, a low-pass filter composed of an inductor (65) and a capacitor (66) filters out the high-frequency component to output a pure low-frequency sine wave AC voltage (refer to the reference waveform 16 shown in FIG. 3), and then passes through the relay (7). The output is filtered by the filtering device (8) and then supplied to the user equipment to continue to supply power. It is to be understood that the detailed description of the embodiments of the present invention is intended to illustrate and explain the principles of the invention Modifications, variations, and modifications may be made to the embodiments of the present invention without departing from the spirit and scope of the invention. The scope is defined by the appended claims and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing the structure of an in-line uninterruptible power supply unit according to a preferred embodiment of the present invention. Fig. 2 is a schematic diagram showing the output waveform of each point of the online uninterruptible power supply device in the presence of mains according to a preferred embodiment of the present invention. Fig. 3 is a diagram showing the output waveform of each point of the online uninterruptible power supply device in the power supply of the battery device according to a preferred embodiment of the present invention. Figure 4 is a block diagram showing the structure of a conventional online uninterruptible power supply unit. [Description of main components] (2) Rectifier (4) Remote control switch (6) DC/AC conversion device (8) Filter device ( 56) First power switch (58) Third power switch (1) Filter device ' (3) Battery device (5) DC/DC converter device (7) Relay ^ (51) (52) (53) (54) ( 55) Winding (57) Second Power Switch (59) Fourth Power Switch (61) (62) (63) (64) Power Switch (65) Inductance (66) Capacitance (501) Diode (502) Filter Capacitor (111 Chopper device (112) fuse • (113) three-phase full-bridge rectifier (114) battery • (115) chopper device (116) fuse (117) inverter device (118) relay device (119) filter device 15